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Sample records for 1-2man rho alpha

  1. Structural basis of carbohydrate recognition by a Man(alpha1-2)Man-specific lectin from Bowringia milbraedii.

    PubMed

    Buts, Lieven; Garcia-Pino, Abel; Wyns, Lode; Loris, Remy

    2006-07-01

    The crystal structure of the seed lectin from the tropical legume Bowringia milbraedii was determined in complex with the disaccharide ligand Man(alpha1-2)Man. In solution, the protein exhibits a dynamic dimer-tetramer equilibrium, consistent with the concanavalin A-type tetramer observed in the crystal. Contacts between the tetramers are mediated almost exclusively through the carbohydrate ligand, resulting in a crystal lattice virtually identical to that of the concanavalin-A:Man(alpha1-2)Man complex, even though both proteins have less than 50% sequence identity. The disaccharide binds exclusively in a "downstream" binding mode, with the non-reducing mannose occupying the monosaccharide-binding site. The reducing mannose is bound in a predominantly polar subsite involving Tyr131, Gln218, and Tyr219. PMID:16567368

  2. Evidence for B- to rho0rho0 Decay and Implications for the CKM Angle alpha

    SciTech Connect

    Aubert, B.

    2007-01-03

    The authors search for the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0}, B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980), and B{sup 0} {yields} f{sub 0}(980) f{sub 0}(980) in a sample of about 384 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find evidence for B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} with 3.5{sigma} significance and measure the branching fraction {Beta} = (1.07 {+-} 0.33 {+-} 0.19) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.87 {+-} 0.13 {+-} 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the CKM unitarity angle {alpha} due to penguin contributions in B {yields} {rho}{rho} decays is 18{sup o} at the 1{sigma} level. They also set upper limits on the B{sup 0} {yields} {rho}{sup 0} f{sub 0}(980) and B{sup 0} {yields} f{sub 0}(980)f{sub 0}(980) decay rates.

  3. Constraints on the CKM Angle alpha in the B to rho rho Decays

    SciTech Connect

    Li, H.

    2004-11-03

    Using a data sample of 122 million {Upsilon}(4S) {yields} B{bar B} decays collected with BABAR detector at the PEP-II asymmetric B factory at SLAC, we measure the time-dependent-asymmetry parameters of the longitudinally polarized component in the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay as C{sub L} = -0.23 {+-} 0.24(stat) {+-} 0.14(syst) and S{sub L} = -0.19 {+-} 0.33(stat) {+-} 0.11(syst). The B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decay mode is also searched for in a data sample of about 227 million B{bar B} pairs. No significant signal is observed, and an upper limit of 1.1 x 10{sup -6} (90% C.L.) on the branching fraction is set. The penguin contribution to the CKM angle {alpha} uncertainty is measured to be 11{sup o}. All results are preliminary.

  4. Limit on the B0 to rho0rho0 Branching Fraction and Implications for the CKM Angle alpha

    SciTech Connect

    Aubert, B.

    2005-01-03

    The authors search for the decay B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} in a data sample of about 227 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at SLAC. They find no significant signal and set an upper limit of 1.1 x 10{sup -6} at 90% CL on the branching fraction. As a result, the uncertainty due to penguin contributions on the CKM unitarity angle {alpha} measured in B {yields} {rho}{rho} decays is 11{sup o} at 68% CL.

  5. A Study of B0 to rho+rho- Decays and Constraints on theCKM Angle alpha

    SciTech Connect

    Aubert, B.

    2007-05-16

    The authors present results from an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decays using (383.6 {+-} 4.2) x 10{sup 6} B{bar B} pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. The measurements of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} branching fraction, longitudinal polarization fraction f{sub L}, and the CP-violating parameters S{sub long} and C{sub long} are: {Beta}(B{sup 0} {yields} {rho}{sup +}{rho}{sup -}) = (25.5 {+-} 2.1(stat){sub -3.9}{sup +3.6}(syst)) x 10{sup -6}, f{sub L} = 0.992 {+-} 0.024(stat){sub -0.013}{sup +0.026}(syst), S{sub long} = -0.17 {+-} 0.20(stat){sub -0.06}{sup +0.05}(syst), C{sub long} = 0.01 {+-} 0.15(stat) {+-} 0.06(syst). The authors determine the unitarity triangle angle {alpha}, using an isospin analysis of B {yields} {rho}{rho} decays. One of the two solutions, {alpha} = [73.1, 117.0]{sup o} at 68% CL is compatible with standard model-based fits of existing data. Constraints on the unitarity triangle are also evaluated using an SU(3) symmetry based approach.

  6. Evidence for B(0) --> rho(0)rho(0) decays and implications for the Cabibbo-Kobayashi-Maskawa angle alpha.

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Pegna, D Lopes; Lynch, G; Mir, L M; Orimoto, T J; Osipenkov, I; Pripstein, M; Roe, N A; Ronan, M T; Tackmann, K; Wenzel, W A; Sanchez, P Del Amo; Barrett, M; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Vetere, M Lo; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Vazquez, W Panduro; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Lae, C K; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Diberder, F Le; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Lodovico, F Di; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; Nardo, G De; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Chauveau, J; David, P; Buono, L Del; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Marco, E Di; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Gioi, L Li; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-03-16

    We search for the decays B(0) --> rho(0)rho(0), B(0) --> rho(0)f(0)(980), and B(0) --> f(0)(980)f(0)(980) in a sample of about 384 x 10(6) Upsilon(4S) --> BB[over] decays collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at Stanford Linear Accelerator Center. We find evidence for B(0) --> rho(0)rho(0) with 3.5 sigma significance and measure the branching fraction B = (1.07 +/- 0.33 +/- 0.19) x 10(-6) and longitudinal polarization fraction f(L) = 0.87 +/- 0.13 +/- 0.04, where the first uncertainty is statistical, and the second is systematic. The uncertainty on the Cabibbo-Kobayashi-Maskawa quark-mixing matrix unitarity angle alpha due to penguin contributions in B --> rho rho decays is 18 degrees at the 1 sigma level. We also set upper limits on the B(0) --> rho(0)f(0)(980) and B(0) --> f(0)(980)f(0)(980) decay rates. PMID:17501042

  7. Improved measurement of B+ --> rho+ rho0 and determination of the quark-mixing phase angle alpha.

    PubMed

    Aubert, B; Karyotakis, Y; Lees, J P; Poireau, V; Prencipe, E; Prudent, X; Tisserand, V; Garra Tico, J; Grauges, E; Lopez, L; Palano, A; Pappagallo, M; Eigen, G; Stugu, B; Sun, L; Battaglia, M; Brown, D N; Kerth, L T; Kolomensky, Yu G; Lynch, G; Osipenkov, I L; Tackmann, K; Tanabe, T; Hawkes, C M; Soni, N; Watson, A T; Koch, H; Schroeder, T; Asgeirsson, D J; Fulsom, B G; Hearty, C; Mattison, T S; McKenna, J A; Barrett, M; Khan, A; Randle-Conde, A; Blinov, V E; Bukin, A D; Buzykaev, A R; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Atmacan, H; Gary, J W; Liu, F; Long, O; Vitug, G M; Yasin, Z; Zhang, L; Sharma, V; Campagnari, C; Hong, T M; Kovalskyi, D; Mazur, M A; Richman, J D; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Martinez, A J; Schalk, T; Schumm, B A; Seiden, A; Winstrom, L O; Cheng, C H; Doll, D A; Echenard, B; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Andreassen, R; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Bloom, P C; Ford, W T; Gaz, A; Hirschauer, J F; Nagel, M; Nauenberg, U; Smith, J G; Wagner, S R; Ayad, R; Soffer, A; Toki, W H; Wilson, R J; Feltresi, E; Hauke, A; Jasper, H; Karbach, M; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Kobel, M J; Nogowski, R; Schubert, K R; Schwierz, R; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Verderi, M; Clark, P J; Playfer, S; Watson, J E; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cecchi, A; Cibinetto, G; Franchini, P; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Santoro, V; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Contri, R; Guido, E; Lo Vetere, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Tosi, S; Chaisanguanthum, K S; Morii, M; Adametz, A; Marks, J; Schenk, S; Uwer, U; Bernlochner, F U; Klose, V; Lacker, H M; Bard, D J; Dauncey, P D; Tibbetts, M; Behera, P K; Chai, X; Charles, M J; Mallik, U; Cochran, J; Crawley, H B; Dong, L; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gao, Y Y; Gritsan, A V; Guo, Z J; Arnaud, N; Béquilleux, J; D'Orazio, A; Davier, M; Firmino da Costa, J; Grosdidier, G; Le Diberder, F; Lepeltier, V; Lutz, A M; Pruvot, S; Roudeau, P; Schune, M H; Serrano, J; Sordini, V; Stocchi, A; Wormser, G; Lange, D J; Wright, D M; Bingham, I; Burke, J P; Chavez, C A; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Touramanis, C; Bevan, A J; Clarke, C K; Di Lodovico, F; Sacco, R; Sigamani, M; Cowan, G; Paramesvaran, S; Wren, A C; Brown, D N; Davis, C L; Denig, A G; Fritsch, M; Gradl, W; Hafner, A; Alwyn, K E; Bailey, D; Barlow, R J; Jackson, G; Lafferty, G D; West, T J; Yi, J I; Anderson, J; Chen, C; Jawahery, A; Roberts, D A; Simi, G; Tuggle, J M; Dallapiccola, C; Salvati, E; Saremi, S; Cowan, R; Dujmic, D; Fisher, P H; Henderson, S W; Sciolla, G; Spitznagel, M; Yamamoto, R K; Zhao, M; Patel, P M; Robertson, S H; Schram, M; Lazzaro, A; Lombardo, V; Palombo, F; Stracka, S; Bauer, J M; Cremaldi, L; Godang, R; Kroeger, R; Summers, D J; Zhao, H W; Simard, M; Taras, P; Nicholson, H; De Nardo, G; Lista, L; Monorchio, D; Onorato, G; Sciacca, C; Raven, G; Snoek, H L; Jessop, C P; Knoepfel, K J; Losecco, J M; Wang, W F; Corwin, L A; Honscheid, K; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Sekula, S J; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Castelli, G; Gagliardi, N; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Del Amo Sanchez, P; Ben-Haim, E; Briand, H; Chauveau, J; Hamon, O; Leruste, Ph; Ocariz, J; Perez, A; Prendki, J; Sitt, S; Gladney, L; Biasini, M; Manoni, E; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cervelli, A; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Lopes Pegna, D; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Anulli, F; Baracchini, E; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Renga, F; Voena, C; Ebert, M; Hartmann, T; Schröder, H; Waldi, R; Adye, T; Franek, B; Olaiya, E O; Wilson, F F; Emery, S; Esteve, L; Hamel de Monchenault, G; Kozanecki, W; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; White, R M; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Benitez, J F; Cenci, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dunwoodie, W; Field, R C; Gabareen, A M; Graham, M T; Grenier, P; Hast, C; Innes, W R; Kaminski, J; Kelsey, M H; Kim, H; Kim, P; Kocian, M L; Leith, D W G S; Li, S; Lindquist, B; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; Neal, H; Nelson, S; O'Grady, C P; Ofte, I; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; Wagner, A P; Weaver, M; West, C A; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Ziegler, V; Burchat, P R; Edwards, A J; Miyashita, T S; Ahmed, S; Alam, M S; Ernst, J A; Pan, B; Saeed, M A; Zain, S B; Spanier, S M; Wogsland, B J; Eckmann, R; Ritchie, J L; Ruland, A M; Schilling, C J; Schwitters, R F; Drummond, B W; Izen, J M; Lou, X C; Bianchi, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Milanes, D A; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Choi, H H F; Hamano, K; King, G J; Kowalewski, R; Lewczuk, M J; Nugent, I M; Roney, J M; Sobie, R J; Gershon, T J; Harrison, P F; Ilic, J; Latham, T E; Mohanty, G B; Puccio, E M T; Band, H R; Chen, X; Dasu, S; Flood, K T; Pan, Y; Prepost, R; Vuosalo, C O; Wu, S L

    2009-04-10

    We present improved measurements of the branching fraction B, the longitudinal polarization fraction f{L}, and the direct CP asymmetry A{CP} in the B meson decay channel B;{+}-->rho;{+}rho;{0}. The data sample was collected with the BABAR detector at SLAC. The results are B(B;{+}-->rho;{+}rho;{0})=(23.7+/-1.4+/-1.4) x 10;{-6}, f{L}=0.950+/-0.015+/-0.006, and A{CP}=-0.054+/-0.055+/-0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle alpha=arg(-V{td}V{tb};/V{ud}V{ub}) to be (92.4{-6.5};{+6.0}) degrees. PMID:19392426

  8. Improved Measurement of B^ \\to\\rho^ \\rho^0 and Determination of the Quark-Mixing Phase Angle~\\alpha

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Tico, J.Garra; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D.N.; Kerth, L.T.; Kolomensky, Yu.G.; Lynch, G.; Osipenkov, I.L.; /Annecy, LAPP /Barcelona U., ECM /INFN, Bari /Bari U. /Bergen U. /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U.

    2009-07-14

    The authors present improved measurements of the branching fraction {Beta}, the longitudinal polarization fraction f{sub L}, and the direct CP asymmetry A{sub CP} in the B meson decay channel B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. The data sample was collected with the BABAR detector at SLAC. The results are {Beta}(B{sup +} {yields} {rho}{sup +}{rho}{sup 0}) = (23.7 {+-} 1.4 {+-} 1.4) x 10{sup -6}, f{sub L} = 0.950 {+-} 0.015 {+-} 0.006, and A{sub CP} = -0.054 {+-} 0.055 {+-} 0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, they perform an isospin analysis and determine the CKM weak phase angle {alpha} to be (92.4{sub -6.5}{sup +6.0}){sup 0}.

  9. Improved Measurement of the Cabibbo-Kobayashi-Maskawa angle alpha using B0(B) --> rho+rho- decays.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Pappagallo, M; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bondioli, M; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Andreassen, R; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Klose, V; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Pierini, M; Plaszczynski, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Graziani, G; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Allen, M T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kazuhito, S; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Thompson, J M; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mellado, B; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-07-22

    We present results from an analysis of B(0)B(0)--> rho(+)rho(-) using 232 x 10(6) Gamma (4S) --> BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We measure the longitudinal polarization fraction f(L) = 0.978 +/- 0.014(stat) + 0.021 / -0.029(syst) and the CP-violating parameters S(L)= -0.33 +/- 0.24(stat) + 0.08 / -0.14(syst) and C(L)= -0.03 +/- 0.18(stat) +/- 0.09(syst). Using an isospin analysis of B --> rhorho decays, we determine the unitarity triangle parameter alpha. The solution compatible with the standard model is alpha = (100 +/- 13) degrees. PMID:16090799

  10. Measuring {alpha} in B(t){yields}{rho}{sup {+-}}{pi}{sup {+-}}

    SciTech Connect

    Gronau, M.; Zupan, J.

    2004-10-01

    Defining a most economical parametrization of time-dependent B{yields}{rho}{sup {+-}}{pi}{sup {+-}} decays, including a measurable phase {alpha}{sub eff} which equals the weak phase {alpha} in the limit of vanishing penguin amplitudes, we propose two ways for determining {alpha} in this processes. We explain the limitation of one method, assuming only that two relevant tree amplitudes factorize and that their relative strong phase {delta}{sub t} is negligible. The other method, based on broken flavor SU(3), permits a determination of {alpha} in B{sup 0}{yields}{rho}{sup {+-}}{pi}{sup {+-}} in an over constrained system using also rate measurements of B{sup 0,+}{yields}K*{pi} and B{sup 0,+}{yields}{rho}K. Current data are shown to restrict two ratios of penguin and tree amplitudes r{sub {+-}} to a narrow range around 0.2 and to imply an upper bound |{alpha}{sub eff}-{alpha}|<15 deg. . Assuming that {delta}{sub t} is much smaller than 90 deg. , we find {alpha}=(93{+-}16) deg. and (102{+-}20) deg. using BABAR and BELLE results for B(t){yields}{rho}{sup {+-}}{pi}{sup {+-}}. Avoiding this assumption for completeness, we demonstrate the reduction of discrete ambiguities in {alpha} with increased statistics and show that SU(3) breaking effects are effectively second order in r{sub {+-}}.

  11. TUMOR NECROSIS FACTOR ALPHA DECREASES NOS3 EXPRESSION PRIMARILY VIA RHO/RHO KINASE IN THE THICK ASCENDING LIMB

    PubMed Central

    Ramseyer, Vanesa; Hong, Nancy; Garvin, Jeffrey L.

    2013-01-01

    Inappropriate Na+ reabsorption by thick ascending limbs (THALs) induces hypertension. Nitric oxide (NO) produced by NO synthase type 3 (NOS3 or eNOS) inhibits NaCl reabsorption by THALs. Tumor necrosis factor alpha (TNF-α) decreases NOS3 expression in endothelial cells and contributes to increases in blood pressure. However, the effects of TNF-α on THAL NOS3 and the signaling cascade are unknown. TNF-α activates several signaling pathways including Rho/Rho kinase (ROCK) which is known to reduce NOS3 expression in endothelial cells. Therefore, we hypothesized that TNF-α decreases NOS3 expression via Rho/ROCK in rat THAL primary cultures. THAL cells were incubated with either vehicle or 1 nmol/L TNF-α for 24 hrs and NOS3 expression was measured by Western blot. TNF-α decreased NOS3 expression by 51±6% (p<0.002) and blunted stimulus-induced NO production. A 10-minutes treatment with TNF-α stimulated RhoA activity by 60±23% (p<0.04). Inhibition of Rho GTPase with 0.05 μg/mL C3 exoenzyme blocked TNF-α-induced reductions in NOS3 expression by 30±8% (p<0.02). Inhibition of ROCK with 10 μmol/L H-1152 blocked TNF-α-induced decreases in NOS3 expression by 66±15 % (p<0.001). Simultaneous inhibition of Rho and ROCK had no additive effect. Myosin light chain kinase, NO, protein kinase C, mitogen-activated kinase kinase, c-Jun amino terminal kinases and Rac-1 were also not involved in TNF-α-induced decreases in NOS3 expression. We conclude that TNF-α decreases NOS3 expression primarily via Rho/ROCK in rat THALs. These data suggest that some of the beneficial effects of ROCK inhibitors in hypertension could be due to the mitigation of TNF-α-induced reduction in NOS3 expression. PMID:22566503

  12. Improved Measurement of B{sup +}{yields}{rho}{sup +}{rho}{sup 0} and Determination of the Quark-Mixing Phase Angle {alpha}

    SciTech Connect

    Aubert, B.; Karyotakis, Y.; Lees, J. P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Battaglia, M.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.

    2009-04-10

    We present improved measurements of the branching fraction B, the longitudinal polarization fraction f{sub L}, and the direct CP asymmetry A{sub CP} in the B meson decay channel B{sup +}{yields}{rho}{sup +}{rho}{sup 0}. The data sample was collected with the BABAR detector at SLAC. The results are B(B{sup +}{yields}{rho}{sup +}{rho}{sup 0})=(23.7{+-}1.4{+-}1.4)x10{sup -6}, f{sub L}=0.950{+-}0.015{+-}0.006, and A{sub CP}=-0.054{+-}0.055{+-}0.010, where the uncertainties are statistical and systematic, respectively. Based on these results, we perform an isospin analysis and determine the Cabibbo-Kobayashi-Maskawa phase angle {alpha}=arg(-V{sub td}V{sub tb}*/V{sub ud}V{sub ub}*) to be (92.4{sub -6.5}{sup +6.0}) deg.

  13. Limit on the B0-->rho0rho0 branching fraction and implications for the Cabibbo-Kobayashi-Maskawa angle alpha.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges-Pous, E; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Weinstein, A J R; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Ruddick, W O; Smith, J G; Ulmer, K A; Zhang, J; Zhang, L; Chen, A; Eckhart, E A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q; Spaan, B; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Nogowski, R; Otto, S; Petzold, A; Schott, G; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Bernard, D; Bonneaud, G R; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Marks, J; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Mohapatra, A K; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Arnaud, N; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Pierini, M; Plaszczynski, S; Schune, M H; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Touramanis, C; Cormack, C M; Di Lodovico, F; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hodgkinson, M C; Lafferty, G D; Naisbit, M T; Williams, J C; Chen, C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Koeneke, K; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Biasini, M; Covarelli, R; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Simi, G; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Christ, S; Schröder, H; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Graziani, G; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dingfelder, J C; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, J; Strube, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Martinez-Vidal, F; Panvini, R S; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Mohanty, G B; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Flood, K T; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihalyi, A; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-04-01

    We search for the decay B0-->rho(0)rho(0) in a data sample of about 227x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) collider at SLAC. We find no significant signal and set an upper limit of 1.1x10(-6) at 90% C.L. on the branching fraction. As a result, the uncertainty due to penguin contributions on the Cabibbo-Kobayashi-Maskawa unitarity angle alpha measured in B-->rhorho decays is decreased to 11 degrees at 68% C.L. PMID:15903984

  14. Measurement of the CKM Angle Alpha at the BABAR Detector Using B Meson Decays to Rho Final States

    SciTech Connect

    Mihalyi, Attila; /Wisconsin U., Madison

    2006-10-16

    This thesis contains the results of an analysis of B{sup 0} {yields} {rho}{sup +}{rho}{sup -} using 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. From a fitted signal yield of 617 {+-} 52 events, the longitudinal polarizations fraction, f{sub L}, of the decay is measured to be 0.978 {+-} 0.014(stat){sub -0.029}{sup +0.021}(syst). The nearly fully longitudinal dominance of the B{sup 0} {yields} {rho}{sup +}{rho}{sup -} decay allows for a measurement of the time dependent CP parameters S{sub L} and C{sub L}, where the first parameter is sensitive to mixing induced CP violation and the second one to direct CP violation. From the same signal yield, these values are found to be S{sub L} = -0.33 {+-} 0.24(stat){sub -0.14}{sup +0.08}(syst) and C{sub L} = - 0.03 {+-} 0.18(stat) {+-} 0.09(syst). The CKM angle {alpha} is then determined, using these results and the branching fractions and polarizations of the decays B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} and B{sup +} {yields} {rho}{sup +}{rho}{sup 0}. This measurement is done with an isospin analysis, in which a triangle is constructed from the isospin amplitudes of these three decay modes. A {chi}{sup 2} expression that includes the measured quantities expressed as the lengths of the sides of the isospin triangles is constructed and minimized to determine a confidence level on {alpha}. Selecting the solution compatible with the Standard Model, one obtains {alpha} = 100{sup o} {+-} 13{sup o}.

  15. Measurement of the Branching Fraction, Polarization, and CP Asymmetries in B0->rho0rho0 Decay, and Implications for the CKM Angle alpha

    SciTech Connect

    Aubert, B

    2008-09-10

    We study B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider located at the Stanford Linear Accelerator Center (SLAC). We measure the branching fraction {Beta} = (0.92 {+-} 0.32 {+-} 0.14) x 10{sup -6} and longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11} {+-} 0.04, where the first uncertainty is statistical and the second is systematic. The evidence for the B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} signal has a significance of 3.1 standard deviations, including systematic uncertainties. We investigate the proper-time dependence of the longitudinal component in the decay and measure the CP-violating coefficients S{sub L}{sup 00} = (0.3 {+-} 0.7 {+-} 0.2) and C{sub L}{sup 00} = (0.2 {+-} 0.8 {+-} 0.3). They study the implication of these results for the unitarity triangle angle {alpha}.

  16. Study of the decay B0(B- 0)-->rho+rho-, and constraints on the Cabibbo-Kobayashi-Maskawa angle alpha.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; LeClerc, C; Lynch, G; Merchant, A M; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Shelkov, V G; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Shen, B C; Wang, K; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Wilden, L; Jessop, C P; LoSecco, J M; Gabriel, T A; Allmendinger, T; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Cristinziani, M; De Nardo, G; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Rubin, A E; Sekula, S J; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2004-12-01

    Using a data sample of 89 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC, we measure the B0(B (0))-->rho(+)rho(-) branching fraction as [30+/-4(stat)+/-5(syst)]x10(-6) and a longitudinal polarization fraction of f(L)=0.99+/-0.03(stat)+0.04-0.03(syst). We measure the time-dependent-asymmetry parameters of the longitudinally polarized component of this decay as C(L)=-0.17+/-0.27(stat)+/-0.14(syst) and S(L)=-0.42+/-0.42(stat)+/-0.14(syst). We exclude values of alpha between 19 degrees and 71 degrees (90% C.L.). PMID:15601142

  17. Activation of p115-RhoGEF Requires Direct Association of G[alpha subscript 13] and the Dbl Homology Domain

    SciTech Connect

    Chen, Zhe; Guo, Liang; Hadas, Jana; Gutowski, Stephen; Sprang, Stephen R.; Sternweis, Paul C.

    2012-09-05

    RGS-containing RhoGEFs (RGS-RhoGEFs) represent a direct link between the G{sub 12} class of heterotrimeric G proteins and the monomeric GTPases. In addition to the canonical Dbl homology (DH) and pleckstrin homology domains that carry out the guanine nucleotide exchange factor (GEF) activity toward RhoA, these RhoGEFs also possess RGS homology (RH) domains that interact with activated {alpha} subunits of G{sub 12} and G{sub 13}. Although the GEF activity of p115-RhoGEF (p115), an RGS-RhoGEF, can be stimulated by G{alpha}{sub 13}, the exact mechanism of the stimulation has remained unclear. Using combined studies with small angle x-ray scattering, biochemistry, and mutagenesis, we identify an additional binding site for activated G{alpha}{sub 13} in the DH domain of p115. Small angle x-ray scattering reveals that the helical domain of G{alpha}{sub 13} docks onto the DH domain, opposite to the surface of DH that binds RhoA. Mutation of a single tryptophan residue in the {alpha}3b helix of DH reduces binding to activated G{alpha}{sub 13} and ablates the stimulation of p115 by G{alpha}{sub 13}. Complementary mutations at the predicted DH-binding site in the {alpha}B-{alpha}C loop of the helical domain of G{alpha}{sub 13} also affect stimulation of p115 by G{alpha}{sub 13}. Although the GAP activity of p115 is not required for stimulation by G{alpha}{sub 13}, two hydrophobic motifs in RH outside of the consensus RGS box are critical for this process. Therefore, the binding of G{alpha}{sub 13} to the RH domain facilitates direct association of G{alpha}{sub 13} to the DH domain to regulate its exchange activity. This study provides new insight into the mechanism of regulation of the RGS-RhoGEF and broadens our understanding of G protein signaling.

  18. Expected accuracy in a measurement of the CKM angle alpha using a Dalitz plot analysis of B0 ---> rho pi decays in the BTeV project

    SciTech Connect

    Shestermanov, K.E.; Vasiliev, A.N; Butler, J.; Derevschikov, A.A.; Kasper, P.; Kiselev, V.V.; Kravtsov, V.I.; Kubota, Y.; Kutschke, R.; Matulenko, Y.A.; Minaev, N.G.; /Serpukhov, IHEP /Fermilab /Minnesota U. /Syracuse U. /INFN, Milan

    2005-12-01

    A precise measurement of the angle {alpha} in the CKM triangle is very important for a complete test of Standard Model. A theoretically clean method to extract {alpha} is provided by B{sup 0} {yields} {rho}{pi} decays. Monte Carlo simulations to obtain the BTeV reconstruction efficiency and to estimate the signal to background ratio for these decays were performed. Finally the time-dependent Dalitz plot analysis, using the isospin amplitude formalism for tre and penguin contributions, was carried out. It was shown that in one year of data taking BTeV could achieve an accuracy on {alpha} better than 5{sup o}.

  19. RhoA-dependent switch between alpha2beta1 and alpha3beta1 integrins is induced by laminin-5 during early stage of HT-29 cell differentiation.

    PubMed

    Gout, S P; Jacquier-Sarlin, M R; Rouard-Talbot, L; Rousselle, P; Block, M R

    2001-10-01

    Integrin-mediated interactions between the basement membrane and epithelial cells control the differentiation of epithelia. We characterized the modulation of adhesive behaviors to basement membrane proteins and of integrin function in the human colon adenocarcinoma HT-29 cell line, which differentiates into enterocytes after the substitution of galactose for glucose in the medium. We demonstrate an increased capability of these cells to adhere to collagen type IV during the early stage of differentiation. This effect occurs without any changes in integrin cell surface expression but rather results from an alpha2beta1/alpha3beta1 integrin switch, alpha3beta1 integrin becoming the major collagen receptor. The increase in laminin-5 secretion and deposit on the matrix is a key factor in the mechanism regulating cell adhesion, because it is responsible for the activation of alpha3beta1 integrin. Furthermore, down-regulation of RhoA GTPase activity occurs during HT-29 cell differentiation and correlates with the activation of the integrin alpha3beta1. Indeed, C3 transferase, a RhoA GTPase inhibitor, induces a similar alpha2beta1/alpha3beta1 switch in undifferentiated HT-29 cells. These results indicate that the decrease in RhoA activation is the biochemical mechanism underlying this integrin switch observed during cell differentiation. The physiological relevance of such modulation of integrin activity in the functioning of the crypt-villus axis is discussed. PMID:11598208

  20. Crystallization and preliminary X-ray analysis of the Man(α1-2)Man-specific lectin from Bowringia mildbraedii in complex with its carbohydrate ligand

    SciTech Connect

    Garcia-Pino, Abel; Loris, Remy; Wyns, Lode; Buts, Lieven

    2005-10-01

    The lectin from the Nigerian legume B. mildbraedii was crystallized in complex with Man(α1-2)Man and data were collected to a resolution of 1.90 Å using synchrotron radiation. The lectin from Bowringia mildbraedii seeds crystallizes in the presence of the disaccharide Man(α1-2)Man. The best crystals grow at 293 K within four weeks after a pre-incubation at 277 K to induce nucleation. A complete data set was collected to a resolution of 1.90 Å using synchrotron radiation. The crystals belong to space group I222, with unit-cell parameters a = 66.06, b = 86.35, c = 91.76 Å, and contain one lectin monomer in the asymmetric unit.

  1. Rho iso-alpha acids from hops inhibit the GSK-3/NF-κB pathway and reduce inflammatory markers associated with bone and cartilage degradation

    PubMed Central

    Konda, Veera Reddy; Desai, Anuradha; Darland, Gary; Bland, Jeffrey S; Tripp, Matthew L

    2009-01-01

    Background Rho iso-alpha acids (RIAA) from hops have been shown to have anti-inflammatory properties. To understand the mechanisms, we evaluated the effect of RIAA in cell signaling pathways and inflammatory markers using various in vitro models. We also investigated their therapeutic effect in mice with collagen-induced arthritis. Methods The LPS-stimulated RAW 264.7 macrophages were used to evaluate the effect of RIAA on the NF-κB and MAPK signaling pathways; phosphorylation of ERK1/2, p38 and JNK was assessed by western blotting and NF-κB binding by electrophoretic mobility shift assays. Effect on the NF-κB activity was evaluated by the luciferase reporter assays in LPS-stimulated RAW 264.7 cells. GSK-3α/β kinase activity was measured in cell-free assays. The inhibitory effect of RIAA on inflammatory markers was assessed by measuring nitric oxide in LPS-stimulated RAW 264.7 cells, RANKL-mediated TRAP activity in transformed osteoclasts, and TNF-α/IL-1β-mediated MMP-13 expression in SW1353 cells. Mice with collagen-induced arthritis were fed with RIAA for 2 weeks. Symptoms of joint swelling, arthritic index and joint damage were assessed. Results RIAA selectively inhibited the NF-κB pathway while having no effect on ERK1/2, p38 and JNK phosphorylation in LPS-stimulated RAW 264.7 cells. RIAA also inhibited GSK-3α/β kinase activity and GSK-3β dependent phosphorylation of β-catenin in RAW 264.7 cells. In addition, RIAA inhibited NF-κB-mediated inflammatory markers in various cell models, including nitric oxide in LPS-stimulated RAW 264.7 cells, RANKL-mediated TRAP activity in transformed osteoclasts, and TNF-α/IL-1β-mediated MMP-13 expression in SW1353 human chondrosarcoma cells. Finally, in a mouse model of collagen-induced arthritis, RIAA ameliorated joint damage as evidenced by significant reduction of the arthritis index and histology score; at 250 mg/kg-body weight, RIAA had efficacy similar to that of 20 mg/kg-body weight of celecoxib

  2. Rho proteins crosstalk via RhoGDIalpha

    PubMed Central

    Stultiens, Audrey; Ho, T. T. Giang; Nusgens, Betty V.; Colige, Alain C.

    2012-01-01

    The small GTPases of the Rho family are key signaling molecules regulating a plethora of biological pathways. They can exert diverse, sometimes opposite, contributions to specific cellular processes explaining why their regulation and their crosstalk must be finely tuned. Several mechanisms driving crosstalk between Rho GTPases have been described in the literature. They implicate proteins regulating their activity or common downstream effectors. Among the proteins regulating Rho GTPases cycling, RhoGDIs were viewed until very recently as passive inhibitors. Here, we will focus on recent data supporting a role for RhoGDIalpha in the crosstalk between RhoGTPases and present our results suggesting that “preferential” RhoGDIalpha-mediated crosstalk takes place between closely related Rho GTPases. PMID:22482023

  3. Search for the Decay B{sup 0} --> {rho}{sup 0} {rho}{sup 0}

    SciTech Connect

    Aubert, B

    2004-08-16

    The B{sup 0} --> {rho}{sup 0}{rho}{sup 0} decay mode is searched for in a data sample of about 227 million {Upsilon}(4S) --> B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric B factory at SLAC. No significant signal is observed, and an upper limit of 1.1x10{sup -6} (90% C.L.) on the branching fraction is set. Implications on the penguin contribution and constraints on the CKM angle {alpha} with B --> {rho}{rho} decays are discussed. All results are preliminary.

  4. Optimized mixture of hops rho iso-alpha acids-rich extract and acacia proanthocyanidins-rich extract reduces insulin resistance in 3T3-L1 adipocytes and improves glucose and insulin control in db/db mice

    PubMed Central

    Darland, Gary; Konda, Veera Reddy; Pacioretty, Linda M.; Chang, Jyh-Lurn; Bland, Jeffrey S.; Babish, John G.

    2012-01-01

    Rho iso-alpha acids-rich extract (RIAA) from Humulus lupulus (hops) and proanthocyanidins-rich extracts (PAC) from Acacia nilotica exert anti-inflammatory and anti-diabetic activity in vitro and in vivo. We hypothesized that a combination of these two extracts would exert enhanced effects in vitro on inflammatory markers and insulin signaling, and on nonfasting glucose and insulin in db/db mice. Over 49 tested combinations, RIAA:PAC at 5:1 (6.25 µg/mL) exhibited the greatest reductions in TNFα-stimulated lipolysis and IL-6 release in 3T3-L1 adipocytes, comparable to 5 µg/mL troglitazone. Pretreatment of 3T3-L1 adipocytes with this combination (5 µg/mL) also led to a 3-fold increase in insulin-stimulated glucose uptake that was comparable to 5 µg/mL pioglitazone or 901 µg/mL aspirin. Finally, db/db mice fed with RIAA:PAC at 5:1 (100 mg/kg) for 7 days resulted in 22% decrease in nonfasting glucose and 19% decrease in insulin that was comparable to 0.5 mg/kg rosiglitazone and better than 100 mg/kg metformin. RIAA:PAC mixture may have the potential to be an alternative when conventional therapy is undesirable or ineffective, and future research exploring its long-term clinical application is warranted. PMID:23198019

  5. Recent Results on the CKM Angle Alpha

    SciTech Connect

    Mihalyi, A.; /Wisconsin U., Madison

    2005-10-18

    The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).

  6. Time Dependent Analysis of B to rho0rho0 Decays

    SciTech Connect

    Osipenkov, Ilya Leonidovich

    2009-12-11

    The BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider is located at the Stanford Linear Accelerator Center. It has been gathering data on the {Upsilon}(4S) resonance from 2000 until 2007 with the primary objective of studying CP violation in B-meson decays. In this thesis they provide a theoretical overview of how CP violation arises in the context of the Standard Model, why B decays are relevant, and how BABAR gathers the necessary data. Specifically, they present the analysis of B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} decays in a sample of 465 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B}. They measure the corresponding branching fraction {Beta} = (0.92 {+-} 0.32(stat.) {+-} 0.14(syst.)) x 10{sup -6} and the longitudinal polarization fraction f{sub L} = 0.75{sub -0.14}{sup +0.11}(stat.) {+-} 0.04(syst.). The evidence for the B{sup 0} {yields} {rho}{sup 0}{rho}{sup 0} signal has a significance of 3.1 standard deviations ({sigma}), when the systematic uncertainties are included. There is insufficient evidence for B decays into similar modes and the corresponding upper limits are determined to be {Beta}{sub {rho}{sup 0}f{sub 0}} < 0.34 x 10{sup -6}, {Beta}{sub f{sub 0}f{sub 0}} < 0.16 x 10{sup -6}, {Beta}{sub {rho}{sup 0}{pi}{sup +}{pi}{sup -}} < 8.7 x 10{sup -6}, B{sub {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -}} < 21.1 x 10{sup -6} at the 90% Confidence Level (CL). They also investigate the proper-time dependence of the longitudinal component in the decay and measure the Cp-violating coefficients S{sub L} = 0.3 {+-} 0.7(stat.) {+-} 0.2(syst.) and C{sub L} = 0.2 {+-} 0.8(stat.) {+-} 0.3(syst.). By combining these results with other measurements from the B {yields} {rho}{rho} processes and performing an Isospin Analysis, they are able to restrict the unitarity angle {alpha} as well as its uncertainty due to penguin contributions, {Delta}{alpha}. Namely, {alpha} = (92.4{sub -6.5}{sup +6.0}){sup o} with -1.8{sup o} < {Delta}{alpha} < 6.7{sup o

  7. The Rho Kappa Spirit

    ERIC Educational Resources Information Center

    McCullagh, Mary T.

    2012-01-01

    Many years ago, Christopher Columbus High School opened a chapter of Rho Kappa, the Social Studies Honor Society developed through the Florida Council for the Social Studies (FCSS). As department chair and member of FCSS, the author was thrilled to be able to offer their students opportunities in the Honor Society for the Social Studies. They…

  8. RhoA/Rho kinase in spinal cord injury

    PubMed Central

    Wu, Xiangbing; Xu, Xiao-ming

    2016-01-01

    A spinal cord injury refers to an injury to the spinal cord that is caused by a trauma instead of diseases. Spinal cord injury includes a primary mechanical injury and a much more complex secondary injury process involving inflammation, oxidation, excitotoxicity, and cell death. During the secondary injury, many signal pathways are activated and play important roles in mediating the pathogenesis of spinal cord injury. Among them, the RhoA/Rho kinase pathway plays a particular role in mediating spinal degeneration and regeneration. In this review, we will discuss the role and mechanism of RhoA/Rho kinase-mediated spinal cord pathogenesis, as well as the potential of targeting RhoA/Rho kinase as a strategy for promoting both neuroprotection and axonal regeneration. PMID:26981071

  9. RhoGAPs and Rho GTPases in platelets.

    PubMed

    Elvers, Margitta

    2016-08-01

    Platelet cytoskeletal reorganization is essential for platelet adhesion and thrombus formation in hemostasis and thrombosis. The Rho GTPases RhoA, Rac1 and Cdc42 are the main players in cytoskeletal dynamics of platelets responsible for the formation of filopodia and lamellipodia to strongly increase the platelet surface upon activation. They are involved in platelet activation and aggregate formation including platelet secretion, integrin activation and arterial thrombus formation. The activity of Rho GTPases is tightly controlled by different proteins such as GTPase-activating proteins (GAPs). GAPs stimulate GTP hydrolysis to terminate Rho signaling. The role and impact of GAPs in platelets is not well-defined and many of the RhoGAPs identified are not known to be present in platelets or to have any function in platelets. The recently identified RhoGAPs Oligophrenin1 (OPHN1) and Nadrin regulate the activity of RhoA, Rac1 and Cdc42 and subsequent platelet cytoskeletal reorganization, platelet activation and thrombus formation. In the last years, the analysis of genetically modified mice helped to gain the understanding of Rho GTPases and their regulators in cytoskeletal rearrangements and other Rho mediated cellular processes in platelets. PMID:25639730

  10. Measurements of Branching Ratios And Search for CP Violation in the Modes B0 to Rho Pi, Rho K

    SciTech Connect

    Laplace, Sandrine; /Paris U., VI-VII

    2006-09-18

    The BABAR experiment, at the PEP-II collider at SLAC, has been studying since 1999 CP violation in the B meson system. After the precise measurement of sin2{beta}, one is now concentrating on measuring the angles {alpha} and {gamma} of the unitarity triangle. The work presented in this thesis concerns the measurement of the angle {alpha} in the B{sup 0} {yields} {rho}{pi} mode.

  11. Cycling Rho for tissue contraction.

    PubMed

    Teo, Jessica L; Yap, Alpha S

    2016-08-29

    Cell contractility, driven by the RhoA GTPase, is a fundamental determinant of tissue morphogenesis. In this issue, Mason et al. (2016. J. Cell Biol http://dx.doi.org/10.1083/jcb.201603077) reveal that cyclic inactivation of RhoA, mediated by its antagonist, C-GAP, is essential for effective contractility to occur. PMID:27551059

  12. Search for the Decay B^0 -> a^\\pm_1 \\rho^\\mp

    SciTech Connect

    Aubert, B.

    2006-05-10

    The authors present a search for the rare B-meson decay B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}} with {alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}. We use (110 {+-} 1.2) x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEp-II asymmetric-energy B Factory at SLAC. They obtain an upper limit of 30 x 10{sup -6} (90% C.L.) for the branching fraction product {Beta}(B{sup 0} {yields} {alpha}{sub 1}{sup {+-}}{rho}{sup {-+}}) {Beta}({alpha}{sub 1}{sup {+-}} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup {+-}}), where they assume that the {alpha}{sub 1}{sup {+-}} decays exclusively to {rho}{sup 0}{pi}{sup {+-}}.

  13. Rho/Rho-associated kinase pathway in glaucoma (Review).

    PubMed

    Wang, Jing; Liu, Xiaohong; Zhong, Yisheng

    2013-11-01

    The Rho/ROCK pathway plays important roles in the modulation of the cytoskeletal integrity of cells, the synthesis of extracellular matrix components in the aqueous humor outflow tissue and the permeability of Schlemm's canal endothelial cells. The activation of the Rho/ROCK pathway results in trabecular meshwork (TM) contraction, and the inhibition of this pathway would provoke relaxation of TM with subsequent increase in outflow facility and, thereby, decrease intraocular pressure (IOP). ROCK inhibitors also serve as potent anti‑scarring agents via inhibition of transdifferentiation of tenon fibroblasts into myofibroblasts. Furthermore, the RhoA/ROCK pathway is involved in optic nerve neuroprotection. Inactivation of Rho/ROCK signaling increase ocular blood flow, improve retinal ganglion cell (RGC) survival and promote RGC axon regeneration. Considering the IOP modulation, potent bleb anti-scarring effect and neuroprotective properties of ROCK inhibitors, the Rho/ROCK pathway is an attractive target for anti-glaucoma therapy, and it may be used for human therapy in the near future. PMID:24042317

  14. Rho A and the Rho kinase pathway regulate fibroblast contraction: Enhanced contraction in constitutively active Rho A fibroblast cells

    SciTech Connect

    Nobe, Koji; Nobe, Hiromi; Yoshida, Hiroko; Kolodney, Michael S.; Paul, Richard J.; Honda, Kazuo

    2010-08-20

    Research highlights: {yields} Mechanisms of fibroblast cell contraction in collagen matrix. {yields} Assessed an isometric force development using 3D-reconstituted-fibroblast fiber. {yields} Constitutively active Rho A induced the over-contraction of fibroblast cells. {yields} Rho A and Rho kinase pathway has a central role in fibroblast cell contraction. -- Abstract: Fibroblast cells play a central role in the proliferation phase of wound healing processes, contributing to force development. The intracellular signaling pathways regulating this non-muscle contraction are only partially understood. To study the relations between Rho A and contractile responses, constitutively active Rho A (CA-Rho A) fibroblast cells were reconstituted into fibers and the effects of calf serum (CS) on isometric force were studied. CS-induced force in CA-Rho A fibroblast fibers was twice as large as that in wild type (NIH 3T3) fibroblast fibers. During this response, the translocation of Rho A from the cytosol to the membrane was detected by Rho A activity assays and Western blot analysis. Pre-treatment with a Rho specific inhibitor (C3-exoenzyme) suppressed translocation as well as contraction. These results indicate that Rho A activation is essential for fibroblast contraction. The Rho kinase inhibitor ( (Y27632)) inhibited both NIH 3T3 and CA-Rho A fibroblast fiber contractions. Activation of Rho A is thus directly coupled with Rho kinase activity. We conclude that the translocation of Rho A from the cytosol to the membrane and the Rho kinase pathway can regulate wound healing processes mediated by fibroblast contraction.

  15. RhoA mediates cyclooxygenase-2 signaling to disrupt the formation of adherens junctions and increase cell motility.

    PubMed

    Chang, Yu-Wen E; Marlin, Jerry W; Chance, Terry W; Jakobi, Rolf

    2006-12-15

    Cyclooxygenase-2 (COX-2) represents an important target for treatment and prevention of colorectal cancer. Although COX-2 signaling is implicated in promoting tumor cell growth and invasion, the molecular mechanisms that mediate these processes are largely unknown. In this study, we show that the RhoA pathway mediates COX-2 signaling to disrupt the formation of adherens junctions and increase cell motility. Disruption of adherens junctions promotes tumor cell invasion and metastasis and is often associated with tumor progression. We detected high levels of RhoA activity in HCA-7 colon carcinoma cells that constitutively express COX-2. Inhibition of COX-2 significantly reduced the levels of RhoA activity in HCA-7 cells, suggesting that constitutive expression of COX-2 stimulates RhoA activity. Interestingly, inhibition of COX-2 or silencing of COX-2 expression with small interfering RNA (siRNA) stimulated the formation of adherens junctions, concomitant with increased protein levels of E-cadherin and alpha-catenin. Furthermore, inhibition of RhoA or silencing of RhoA expression with siRNA increased the levels of E-cadherin and alpha-catenin. Inhibition of Rho kinases (ROCK), the RhoA effector proteins, also increased levels of E-cadherin and alpha-catenin and stimulated formation of adherens junctions. The motility of HCA-7 cells was significantly decreased when COX-2 or RhoA was inhibited. Therefore, our data reveal a novel molecular mechanism that links COX-2 signaling to disrupt the formation of adherens junctions; COX-2 stimulates the RhoA/ROCK pathway, which reduces levels of E-cadherin and alpha-catenin leading to disruption of adherens junction formation and increased motility. Understanding of COX-2 downstream signaling pathways that promote tumor progression is crucial for the development of novel therapeutic strategies. PMID:17178865

  16. Rational design of small molecule inhibitors targeting RhoA subfamily Rho GTPases

    PubMed Central

    Shang, Xun; Marchioni, Fillipo; Sipes, Nisha; Evelyn, Chris R.; Jerabek-Willemsen, Moran; Duhr, Stefan; Seibel, William; Wortman, Matthew; Zheng, Yi

    2012-01-01

    SUMMARY Rho GTPases have been implicated in diverse cellular functions and are potential therapeutic targets. By virtual screening, we have identified a Rho specific inhibitor, Rhosin. Rhosin contains two-aromatic rings tethered by a linker, and it binds to the surface area sandwiching Trp58 of RhoA with a submicromolar Kd and effectively inhibits GEF-catalyzed RhoA activation. In cells Rhosin specifically inhibited RhoA activity and RhoA-mediated cellular function without affecting Cdc42 or Rac1 signaling activities. By suppressing RhoA or RhoC activity Rhosin could inhibit mammary sphere formation by breast cancer cells, suppress invasion of mammary epithelial cells, and induce neurite outgrowth of PC12 cells in synergy with NGF. Thus, the rational designed RhoA subfamily specific small molecule inhibitor is useful for studying the physiological and pathologic roles of Rho GTPase. PMID:22726684

  17. Deregulation of Rho GTPases in cancer

    PubMed Central

    Porter, Andrew P.; Papaioannou, Alexandra; Malliri, Angeliki

    2016-01-01

    ABSTRACT In vitro and in vivo studies and evidence from human tumors have long implicated Rho GTPase signaling in the formation and dissemination of a range of cancers. Recently next generation sequencing has identified direct mutations of Rho GTPases in human cancers. Moreover, the effects of ablating genes encoding Rho GTPases and their regulators in mouse models, or through pharmacological inhibition, strongly suggests that targeting Rho GTPase signaling could constitute an effective treatment. In this review we will explore the various ways in which Rho signaling can be deregulated in human cancers. PMID:27104658

  18. RhoG regulates anoikis through a phosphatidylinositol 3-kinase-dependent mechanism

    SciTech Connect

    Yamaki, Nao; Negishi, Manabu; Katoh, Hironori . E-mail: hirokato@pharm.kyoto-u.ac.jp

    2007-08-01

    In normal epithelial cells, cell-matrix interaction is required for cell survival and proliferation, whereas disruption of this interaction causes epithelial cells to undergo apoptosis called anoikis. Here we show that the small GTPase RhoG plays an important role in the regulation of anoikis. HeLa cells are capable of anchorage-independent cell growth and acquire resistance to anoikis. We found that RNA interference-mediated knockdown of RhoG promoted anoikis in HeLa cells. Previous studies have shown that RhoG activates Rac1 and induces several cellular functions including promotion of cell migration through its effector ELMO and the ELMO-binding protein Dock180 that function as a Rac-specific guanine nucleotide exchange factor. However, RhoG-induced suppression of anoikis was independent of the ELMO- and Dock180-mediated activation of Rac1. On the other hand, the regulation of anoikis by RhoG required phosphatidylinositol 3-kinase (PI3K) activity, and constitutively active RhoG bound to the PI3K regulatory subunit p85{alpha} and induced the PI3K-dependent phosphorylation of Akt. Taken together, these results suggest that RhoG protects cells from apoptosis caused by the loss of anchorage through a PI3K-dependent mechanism, independent of its activation of Rac1.

  19. RhoG regulates anoikis through a phosphatidylinositol 3-kinase-dependent mechanism.

    PubMed

    Yamaki, Nao; Negishi, Manabu; Katoh, Hironori

    2007-08-01

    In normal epithelial cells, cell-matrix interaction is required for cell survival and proliferation, whereas disruption of this interaction causes epithelial cells to undergo apoptosis called anoikis. Here we show that the small GTPase RhoG plays an important role in the regulation of anoikis. HeLa cells are capable of anchorage-independent cell growth and acquire resistance to anoikis. We found that RNA interference-mediated knockdown of RhoG promoted anoikis in HeLa cells. Previous studies have shown that RhoG activates Rac1 and induces several cellular functions including promotion of cell migration through its effector ELMO and the ELMO-binding protein Dock180 that function as a Rac-specific guanine nucleotide exchange factor. However, RhoG-induced suppression of anoikis was independent of the ELMO- and Dock180-mediated activation of Rac1. On the other hand, the regulation of anoikis by RhoG required phosphatidylinositol 3-kinase (PI3K) activity, and constitutively active RhoG bound to the PI3K regulatory subunit p85alpha and induced the PI3K-dependent phosphorylation of Akt. Taken together, these results suggest that RhoG protects cells from apoptosis caused by the loss of anchorage through a PI3K-dependent mechanism, independent of its activation of Rac1. PMID:17570359

  20. Rho GTPases and their effector proteins.

    PubMed Central

    Bishop, A L; Hall, A

    2000-01-01

    Rho GTPases are molecular switches that regulate many essential cellular processes, including actin dynamics, gene transcription, cell-cycle progression and cell adhesion. About 30 potential effector proteins have been identified that interact with members of the Rho family, but it is still unclear which of these are responsible for the diverse biological effects of Rho GTPases. This review will discuss how Rho GTPases physically interact with, and regulate the activity of, multiple effector proteins and how specific effector proteins contribute to cellular responses. To date most progress has been made in the cytoskeleton field, and several biochemical links have now been established between GTPases and the assembly of filamentous actin. The main focus of this review will be Rho, Rac and Cdc42, the three best characterized mammalian Rho GTPases, though the genetic analysis of Rho GTPases in lower eukaryotes is making increasingly important contributions to this field. PMID:10816416

  1. Cholecystokinin-Mediated RhoGDI Phosphorylation via PKCα Promotes both RhoA and Rac1 Signaling

    PubMed Central

    Sabbatini, Maria Eugenia; Williams, John A.

    2013-01-01

    RhoA and Rac1 have been implicated in the mechanism of CCK-induced amylase secretion from pancreatic acini. In all cell types studied to date, inactive Rho GTPases are present in the cytosol bound to the guanine nucleotide dissociation inhibitor RhoGDI. Here, we identified the switch mechanism regulating RhoGDI1-Rho GTPase dissociation and RhoA translocation upon CCK stimulation in pancreatic acini. We found that both Gα13 and PKC, independently, regulate CCK-induced RhoA translocation and that the PKC isoform involved is PKCα. Both RhoGDI1 and RhoGDI3, but not RhoGDI2, are expressed in pancreatic acini. Cytosolic RhoA and Rac1 are associated with RhoGDI1, and CCK-stimulated PKCα activation releases the complex. Overexpression of RhoGDI1, by binding RhoA, inhibits its activation, and thereby, CCK-induced apical amylase secretion. RhoA translocation is also inhibited by RhoGDI1. Inactive Rac1 influences CCK-induced RhoA activation by preventing RhoGDI1 from binding RhoA. By mutational analysis we found that CCK-induced PKCα phosphorylation on RhoGDI1 at Ser96 releases RhoA and Rac1 from RhoGDI1 to facilitate Rho GTPases signaling. PMID:23776598

  2. Rho guanine nucleotide exchange factors: regulators of Rho GTPase activity in development and disease

    PubMed Central

    Cook, Danielle R.; Rossman, Kent L.; Der, Channing J.

    2016-01-01

    The aberrant activity of Ras homologous (Rho) family small GTPases (20 human members) has been implicated in cancer and other human diseases. However, in contrast to the direct mutational activation of Ras found in cancer and developmental disorders, Rho GTPases are activated most commonly by indirect mechanisms in disease. One prevalent mechanism involves aberrant Rho activation via the deregulated expression and/or activity of Rho family guanine nucleotide exchange factors (RhoGEFs). RhoGEFs promote formation of the active GTP-bound state of Rho GTPases. The largest family of RhoGEFs is comprised of the Dbl family RhoGEFs with 70 human members. The multitude of RhoGEFs that activate a single Rho GTPase reflect the very specific role of each RhoGEF in controlling distinct signaling mechanisms involved in Rho activation. In this review, we summarize the role of Dbl RhoGEFs in development and disease, with a focus on Ect2, Tiam1, Vav and P-Rex1/2. PMID:24037532

  3. Control of Polarized Growth by the Rho Family GTPase Rho4 in Budding Yeast: Requirement of the N-Terminal Extension of Rho4 and Regulation by the Rho GTPase-Activating Protein Bem2

    PubMed Central

    Gong, Ting; Liao, Yuan; He, Fei; Yang, Yang; Yang, Dan-Dan; Chen, Xiang-Dong

    2013-01-01

    In the budding yeast Saccharomyces cerevisiae, Rho4 GTPase partially plays a redundant role with Rho3 in the control of polarized growth, as deletion of RHO4 and RHO3 together, but not RHO4 alone, caused lethality and a loss of cell polarity at 30°C. Here, we show that overexpression of the constitutively active rho4Q131L mutant in an rdi1Δ strain caused a severe growth defect and generated large, round, unbudded cells, suggesting that an excess of Rho4 activity could block bud emergence. We also generated four temperature-sensitive rho4-Ts alleles in a rhorho4Δ strain. These mutants showed growth and morphological defects at 37°C. Interestingly, two rho4-Ts alleles contain mutations that cause amino acid substitutions in the N-terminal region of Rho4. Rho4 possesses a long N-terminal extension that is unique among the six Rho GTPases in the budding yeast but is common in Rho4 homologs in other yeasts and filamentous fungi. We show that the N-terminal extension plays an important role in Rho4 function since rhorho4Δ61 cells expressing truncated Rho4 lacking amino acids (aa) 1 to 61 exhibited morphological defects at 24°C and a growth defect at 37°C. Furthermore, we show that Rho4 interacts with Bem2, a Rho GTPase-activating protein (RhoGAP) for Cdc42 and Rho1, by yeast two-hybrid, bimolecular fluorescence complementation (BiFC), and glutathione S-transferase (GST) pulldown assays. Bem2 specifically interacts with the GTP-bound form of Rho4, and the interaction is mediated by its RhoGAP domain. Overexpression of BEM2 aggravates the defects of rhorho4 mutants. These results suggest that Bem2 might be a novel GAP for Rho4. PMID:23264647

  4. Atorvastatin but not elocalcitol increases sildenafil responsiveness in spontaneously hypertensive rats by regulating the RhoA/ROCK pathway.

    PubMed

    Fibbi, Benedetta; Morelli, Annamaria; Marini, Mirca; Zhang, Xin-Hua; Mancina, Rosa; Vignozzi, Linda; Filippi, Sandra; Chavalmane, Aravinda; Silvestrini, Enrico; Colli, Enrico; Adorini, Luciano; Vannelli, Gabriella Barbara; Maggi, Mario

    2008-01-01

    Spontaneously hypertensive rats (SHR) are characterized by impaired erectile function and overactivity of the procontractile RhoA/Rho-associated, coiled-coil-containing protein kinase (RhoA/ROCK) pathway, as compared with their normotensive counterpart, Wistar-Kyoto rats. By measuring the intracavernous pressure:mean arterial pressure (ICP:MAP) ratio after electrostimulation of the cavernous nerve, we confirmed these findings and showed that responsiveness to sildenafil (25 mg/kg by oral gavage) also is hampered in SHR. A 2-week treatment with atorvastatin (5 and 30 mg/kg) improved the sildenafil-induced ICP:MAP increase and normalized RhoA and ROCK2 overexpression in SHR corpora cavernosa (CC). Conversely, other genes, neuronal nitric oxide synthase (NOS), endothelial NOS, and phosphodiesterase 5, were unaffected. In human fetal smooth muscle cells derived from CC (hfPSMC), atorvastatin inhibited RhoA membrane translocation and ROCK activity, as well as RhoA-dependent biologic functions like cell migration and cell proliferation. Atorvastatin's effect on migration was rescued in a dose-dependent manner by geranylgeranyl pyrophosphate, suggesting the involvement of RhoA geranylgeranylation. In hfPSMC, atorvastatin decreased the expression of RhoA-dependent genes such as ROCK2, desmin, alpha-smooth muscle actin, SM22alpha, and myocardin. In contrast to atorvastatin, elocalcitol, a vitamin D analog that also interferes with RhoA activation in SHR bladder, was unable to restore penile responsiveness to sildenafil. In conclusion, atorvastatin, but not elocalcitol, ameliorates sildenafil-induced penile erections in SHR, likely by interfering with RhoA/ROCK signaling within the penis. PMID:17699803

  5. Plasma membrane restricted RhoGEF activity is sufficient for RhoA-mediated actin polymerization

    PubMed Central

    van Unen, Jakobus; Reinhard, Nathalie R.; Yin, Taofei; Wu, Yi I.; Postma, Marten; Gadella, Theodorus W.J.; Goedhart, Joachim

    2015-01-01

    The small GTPase RhoA is involved in cell morphology and migration. RhoA activity is tightly regulated in time and space and depends on guanine exchange factors (GEFs). However, the kinetics and subcellular localization of GEF activity towards RhoA are poorly defined. To study the mechanism underlying the spatiotemporal control of RhoA activity by GEFs, we performed single cell imaging with an improved FRET sensor reporting on the nucleotide loading state of RhoA. By employing the FRET sensor we show that a plasma membrane located RhoGEF, p63RhoGEF, can rapidly activate RhoA through endogenous GPCRs and that localized RhoA activity at the cell periphery correlates with actin polymerization. Moreover, synthetic recruitment of the catalytic domain derived from p63RhoGEF to the plasma membrane, but not to the Golgi apparatus, is sufficient to activate RhoA. The synthetic system enables local activation of endogenous RhoA and effectively induces actin polymerization and changes in cellular morphology. Together, our data demonstrate that GEF activity at the plasma membrane is sufficient for actin polymerization via local RhoA signaling. PMID:26435194

  6. Rho Kinases and Cardiac Remodeling.

    PubMed

    Shimizu, Toru; Liao, James K

    2016-06-24

    Hypertensive cardiac remodeling is characterized by left ventricular hypertrophy and interstitial fibrosis, which can lead to heart failure with preserved ejection fraction. The Rho-associated coiled-coil containing kinases (ROCKs) are members of the serine/threonine protein kinase family, which mediates the downstream effects of the small GTP-binding protein RhoA. There are 2 isoforms: ROCK1 and ROCK2. They have different functions in different types of cells and tissues. There is growing evidence that ROCKs contribute to the development of cardiovascular diseases, including cardiac fibrosis, hypertrophy, and subsequent heart failure. Recent experimental studies using ROCK inhibitors, such as fasudil, have shown the benefits of ROCK inhibition in cardiac remodeling. Mice lacking each ROCK isoform also exhibit reduced myocardial fibrosis in a variety of pathological models of cardiac remodeling. Indeed, clinical studies with fasudil have suggested that ROCKs could be potential novel therapeutic targets for cardiovascular diseases. In this review, we summarize the current understanding of the roles of ROCKs in the development of cardiac fibrosis and hypertrophy and discuss their therapeutic potential for deleterious cardiac remodeling. (Circ J 2016; 80: 1491-1498). PMID:27251065

  7. RhoGDI3 and RhoG: Vesicular trafficking and interactions with the Sec3 Exocyst subunit.

    PubMed

    Morin, Annie; Cordelières, Fabrice P; Cherfils, Jacqueline; Olofsson, Birgitta

    2010-11-01

    RhoGDIs are negative regulators of small GTP-binding proteins of the Rho family, which have essential cellular functions in most aspects of actin-based morphology and motility processes. They extract Rho proteins from membranes, keep them in inactive rhoGDI/Rho complexes and eventually deliver them again to specific membranes in response to cellular signals. RhoGDI3, the most divergent member of the rhoGDI family, is well suited to document the underlying molecular mechanisms, since the active and inactive forms of its cellular target, RhoG, have well-separated subcellular localizations. In this study, we investigate trafficking structures and molecular interactions involved in rhoGDI3-mediated shuttling of RhoG between the Golgi and the plasma membrane.Bimolecular fluorescence complementation and acceptor-photobleaching FRET experiments suggest that rhoGDI3 and RhoG form complexes on Golgi and vesicular structures in mammalian cells. 4D-videomicroscopy confirms this localization, and show that RhoG/rhoGDI3-labelled structures are less dynamic than RhoG and rhoGDI3-labeled vesicles, consistent with the inhibitory function of rhoGDI3. Next, we identify the Exocyst subunit Sec3 as a candidate rhoGDI3 partner in cells. RhoGDI3 relocates a subcomplex of the Exocyst (Sec3 and Sec8) from the cytoplasm to the Golgi, while Sec6 is unaffected. Remarkably, Sec3 increases the level of GTP-bound endogenous RhoG, the RhoG-dependent induction of membrane ruffles, and the formation of intercellular tunneling nanotube-like protrusions.Altogether, our study identifies a novel link between vesicular traffic and the regulation of Rho proteins by rhoGDIs. It also suggests that components of the Exocyst machinery may be involved in RhoG functions, possibly regulated by rhoGDI3. PMID:21686268

  8. Rho GTPase signalling in cell migration

    PubMed Central

    Ridley, Anne J

    2015-01-01

    Cells migrate in multiple different ways depending on their environment, which includes the extracellular matrix composition, interactions with other cells, and chemical stimuli. For all types of cell migration, Rho GTPases play a central role, although the relative contribution of each Rho GTPase depends on the environment and cell type. Here, I review recent advances in our understanding of how Rho GTPases contribute to different types of migration, comparing lamellipodium-driven versus bleb-driven migration modes. I also describe how cells migrate across the endothelium. In addition to Rho, Rac and Cdc42, which are well known to regulate migration, I discuss the roles of other less-well characterized members of the Rho family. PMID:26363959

  9. Regulating Rho GTPases and their regulators.

    PubMed

    Hodge, Richard G; Ridley, Anne J

    2016-08-01

    Rho GTPases regulate cytoskeletal and cell adhesion dynamics and thereby coordinate a wide range of cellular processes, including cell migration, cell polarity and cell cycle progression. Most Rho GTPases cycle between a GTP-bound active conformation and a GDP-bound inactive conformation to regulate their ability to activate effector proteins and to elicit cellular responses. However, it has become apparent that Rho GTPases are regulated by post-translational modifications and the formation of specific protein complexes, in addition to GTP-GDP cycling. The canonical regulators of Rho GTPases - guanine nucleotide exchange factors, GTPase-activating proteins and guanine nucleotide dissociation inhibitors - are regulated similarly, creating a complex network of interactions to determine the precise spatiotemporal activation of Rho GTPases. PMID:27301673

  10. Investigation of the association between Rho/Rho-kinase gene polymorphisms and systemic sclerosis.

    PubMed

    Pehlivan, Yavuz; Yolbas, Servet; Cetin, Gozde Yıldırım; Alibaz-Oner, Fatma; Cagatay, Yonca; Yilmaz, Neslihan; Oztuzcu, Serdar; Donmez, Salim; Ozgen, Metin; Koca, Suleyman Serdar; Pamuk, Omer Nuri; Sayarlıoglu, Mehmet; Kisacik, Bunyamin; Direskeneli, Haner; Demiryurek, Abdullah Tuncay; Onat, Ahmet Mesut

    2016-03-01

    Systemic sclerosis (SSc) is a disease characterized by inflammation, vascular abnormalities and fibrosis. The role of Rho/Rho-kinase pathway was demonstrated in the pathogenesis of fibrosis, inflammation and vascular abnormalities. This study was aimed to investigate the relation between SSc and Rho/Rho-kinase gene polymorphisms. The study included 339 patients with SSc and 302 healthy subjects who were apparently healthy and at similar age and gender. Genotype distributions and allele frequencies were detected by using Chi-square test or Fisher's exact Chi-square test between groups, and the haplotype analysis was applied using online program (SHEsis). Significant association was found in a polymorphism in the ROCK1 gene (rs35996865), a polymorphism in ROCK2 gene (rs10178332), a polymorphism in RhoA gene (rs2177268) and two polymorphisms in RhoC gene (rs11102522 and rs11538960) with SSc disease (p < 0.0022). In this study, association between SSc disease and Rho/Rho-kinase gene polymorphisms was investigated for the first time; significant associations between ROCK1, ROCK2, RhoA and RhoC gene polymorphisms and SSc disease were demonstrated. The results strongly suggest that this SNP may be an important risk factor for development of SSc. However, further validation of these findings in an independent cohort is necessary. PMID:26615410

  11. Atypical Rho GTPases of the RhoBTB Subfamily: Roles in Vesicle Trafficking and Tumorigenesis

    PubMed Central

    Ji, Wei; Rivero, Francisco

    2016-01-01

    RhoBTB proteins constitute a subfamily of atypical Rho GTPases represented in mammals by RhoBTB1, RhoBTB2, and RhoBTB3. Their characteristic feature is a carboxyl terminal extension that harbors two BTB domains capable of assembling cullin 3-dependent ubiquitin ligase complexes. The expression of all three RHOBTB genes has been found reduced or abolished in a variety of tumors. They are considered tumor suppressor genes and recent studies have strengthened their implication in tumorigenesis through regulation of the cell cycle and apoptosis. RhoBTB3 is also involved in retrograde transport from endosomes to the Golgi apparatus. One aspect that makes RhoBTB proteins atypical among the Rho GTPases is their proposed mechanism of activation. No specific guanine nucleotide exchange factors or GTPase activating proteins are known. Instead, RhoBTB might be activated through interaction with other proteins that relieve their auto-inhibited conformation and inactivated through auto-ubiquitination and destruction in the proteasome. In this review we discuss our current knowledge on the molecular mechanisms of action of RhoBTB proteins and the implications for tumorigenesis and other pathologic conditions. PMID:27314390

  12. T1rho and T2rho MRI in the evaluation of Parkinson's disease.

    PubMed

    Nestrasil, I; Michaeli, S; Liimatainen, T; Rydeen, C E; Kotz, C M; Nixon, J P; Hanson, T; Tuite, Paul J

    2010-06-01

    Prior work has shown that adiabatic T(1rho) and T(2rho) relaxation time constants may have sensitivity to cellular changes and the presence of iron, respectively, in Parkinson's disease (PD). Further understanding of these magnetic resonance imaging (MRI) methods and how they relate to measures of disease severity and progression in PD is needed. Using T(1rho) and T(2rho) on a 4T MRI scanner, we assessed the substantia nigra (SN) of nine non-demented moderately affected PD and ten gender- and age-matched control participants. When compared to controls, the SN of PD subjects had increased T(1rho) and reduced T(2rho). We also found a significant correlation between asymmetric motor features and asymmetry based on T(1rho). This study provides additional validation of T(1rho) and T(2rho) as a means to separate PD from control subjects, and T(1rho) may be a useful marker of asymmetry in PD. PMID:20058018

  13. Measurement of the B+- to rho pi0 Branching Fraction and Direct CP Asymmetry

    SciTech Connect

    Aubert, B.

    2007-01-25

    The authors present improved measurements of the branching fraction and CP asymmetry for the process B{sup {+-}} {yields} {rho}{sup {+-}}{pi}{sup 0}. The data sample corresponding to 211 fb{sup -1} comprises 232 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. The yield and CP asymmetry are measured using an extended maximum likelihood fitting method. The branching fraction and Cp asymmetry are found to be {Beta}(B{sup {+-}} {yields} {rho}{sup {+-}}{pi}{sup 0}) = [10.2 {+-} 1.4(stat) {+-} 0.9(syst)] x 10{sup -6} and {Alpha}{sub CP}(B{sup {+-}} {yields} {rho}{sup {+-}}{pi}{sup 0}) = -0.01 {+-} 0.13(stat) {+-} 0.02(syst).

  14. Rho GTPase RhoJ is Associated with Gastric Cancer Progression and Metastasis

    PubMed Central

    Kim, Chan; Yang, Hannah; Park, Intae; Chon, Hong Jae; Kim, Joo Hoon; Kwon, Woo Sun; Lee, Won Suk; Kim, Tae Soo; Rha, Sun Young

    2016-01-01

    Rho GTPases play a pivotal role in tumor progression by regulating tumor cell migration and invasion. However, the role of Rho GTPases in gastric cancer (GC) remains unexplored. This study aimed to investigate the clinical implications of RhoJ, which is an uncharted member of Rho family. RhoJ expression in human GC cell lines and surgical specimens from GC patients were analyzed. Moreover, in vitro gain-of-function analysis was performed to evaluate the malignant phenotypes of RhoJ-overexpressing GC cells. The extent of RhoJ expression varied among GC cell lines and GC patients. YCC-9 cell line displayed the strongest expression, while YCC-10, -11, and -16 showed scant expressions. Of the 70 GC patients, 34 (48.6%) had RhoJ expression in their GC tissue, and patients with high RhoJ expression had more diffuse type GC (73.5% vs. 41.7%), were at more advanced stages (stage III, IV: 85.3% vs. 58.4%), and had more frequent metastasis (47.1% vs. 11.1%), denoting that RhoJ has a potential role in GC progression and metastasis. High RhoJ expression significantly correlated with poor overall survival and recurrence-free survival after surgical resection of gastric cancer. Finally, In vitro gain-of-function experiments showed 41.3% enhanced motility and 60.4% enhanced invasiveness in RhoJ-overexpressing GC cells compared to control, with negligible difference in cell proliferation. Collectively, high RhoJ expression is an independent negative prognostic factor for the survival outcome of GC and correlated with the increased cell motility and invasiveness. PMID:27471571

  15. Rho-associated kinase, a novel serine/threonine kinase, as a putative target for small GTP binding protein Rho.

    PubMed Central

    Matsui, T; Amano, M; Yamamoto, T; Chihara, K; Nakafuku, M; Ito, M; Nakano, T; Okawa, K; Iwamatsu, A; Kaibuchi, K

    1996-01-01

    The small GTP binding protein Rho is implicated in cytoskeletal responses to extracellular signals such as lysophosphatidic acid to form stress fibers and focal contacts. Here we have purified a Rho-interacting protein with a molecular mass of approximately 164 kDa (p164) from bovine brain. This protein bound to GTPgammaS (a non-hydrolyzable GTP analog).RhoA but not to GDP.RhoA or GTPgammaS.RhoA with a mutation in the effector domain (RhoAA37).p164 had a kinase activity which was specifically stimulated by GTPgammaS.RhoA. We obtained the cDNA encoding p164 on the basis of its partial amino acid sequences and named it Rho-associated kinase (Rho-kinase). Rho-kinase has a catalytic domain in the N-terminal portion, a coiled coil domain in the middle portion and a zinc finger-like motif in the C-terminal portion. The catalytic domain shares 72% sequence homology with that of myotonic dystrophy kinase and the coiled coil domain contains a Rho-interacting interface. When COS7 cells were cotransfected with Rho-kinase and activated RhoA, some Rho-kinase was recruited to membranes. Thus it is likely that Rho-kinase is a putative target serine/threonine kinase for Rho and serves as a mediator of the Rho-dependent signaling pathway. Images PMID:8641286

  16. Rho GTPase Recognition by C3 Exoenzyme Based on C3-RhoA Complex Structure.

    PubMed

    Toda, Akiyuki; Tsurumura, Toshiharu; Yoshida, Toru; Tsumori, Yayoi; Tsuge, Hideaki

    2015-08-01

    C3 exoenzyme is a mono-ADP-ribosyltransferase (ART) that catalyzes transfer of an ADP-ribose moiety from NAD(+) to Rho GTPases. C3 has long been used to study the diverse regulatory functions of Rho GTPases. How C3 recognizes its substrate and how ADP-ribosylation proceeds are still poorly understood. Crystal structures of C3-RhoA complex reveal that C3 recognizes RhoA via the switch I, switch II, and interswitch regions. In C3-RhoA(GTP) and C3-RhoA(GDP), switch I and II adopt the GDP and GTP conformations, respectively, which explains why C3 can ADP-ribosylate both nucleotide forms. Based on structural information, we successfully changed Cdc42 to an active substrate with combined mutations in the C3-Rho GTPase interface. Moreover, the structure reflects the close relationship among Gln-183 in the QXE motif (C3), a modified Asn-41 residue (RhoA) and NC1 of NAD(H), which suggests that C3 is the prototype ART. These structures show directly for the first time that the ARTT loop is the key to target protein recognition, and they also serve to bridge the gaps among independent studies of Rho GTPases and C3. PMID:26067270

  17. Photoproduction of the rho meson and its magnetic moments

    SciTech Connect

    Kaneko, Hiromi; Hosaka, Atsushi; Scholten, Olaf

    2011-10-21

    We study photoproduction of {rho} meson in a model of hidden local symmetry. We introduce the {rho} meson on a hidden gauge boson and phenomenological {rho} meson-nucleon Lagrangian is constructed respecting chiral symmetry. It turns out that the {sigma}-exchange interaction plays an important role in neutral {rho} meson photoproduction to reproduce the experimental cross sections. In charged {rho} meson photoproduction, the model takes into account the {rho} meson magnetic moments from the three-point vertex in the kinetic terms. We show that the magnetic moment of the charged {rho} meson has a significant effect on the total cross sections in proportion to the photon energies.

  18. Noncanonical Myo9b-RhoGAP Accelerates RhoA GTP Hydrolysis by a Dual-Arginine-Finger Mechanism.

    PubMed

    Yi, Fengshuang; Kong, Ruirui; Ren, Jinqi; Zhu, Li; Lou, Jizhong; Wu, Jane Y; Feng, Wei

    2016-07-31

    The GTP hydrolysis activities of Rho GTPases are stimulated by GTPase-activating proteins (GAPs), which contain a RhoGAP domain equipped with a characteristic arginine finger and an auxiliary asparagine for catalysis. However, the auxiliary asparagine is missing in the RhoGAP domain of Myo9b (Myo9b-RhoGAP), a unique motorized RhoGAP that specifically targets RhoA for controlling cell motility. Here, we determined the structure of Myo9b-RhoGAP in complex with GDP-bound RhoA and magnesium fluoride. Unexpectedly, Myo9b-RhoGAP contains two arginine fingers at its catalytic site. The first arginine finger resembles the one within the canonical RhoGAP domains and inserts into the nucleotide-binding pocket of RhoA, whereas the second arginine finger anchors the Switch I loop of RhoA and interacts with the nucleotide, stabilizing the transition state of GTP hydrolysis and compensating for the lack of the asparagine. Mutating either of the two arginine fingers impaired the catalytic activity of Myo9b-RhoGAP and affected the Myo9b-mediated cell migration. Our data indicate that Myo9b-RhoGAP accelerates RhoA GTP hydrolysis by a previously unknown dual-arginine-finger mechanism, which may be shared by other noncanonical RhoGAP domains lacking the auxiliary asparagine. PMID:27363609

  19. Hyperosmotic stress activates Rho: differential involvement in Rho kinase-dependent MLC phosphorylation and NKCC activation.

    PubMed

    Di Ciano-Oliveira, Caterina; Sirokmány, Gábor; Szászi, Katalin; Arthur, William T; Masszi, András; Peterson, Mark; Rotstein, Ori D; Kapus, András

    2003-09-01

    Hyperosmotic stress initiates adaptive responses, including phosphorylation of myosin light chain (MLC) and concomitant activation of Na+-K+-Cl- cotransporter (NKCC). Because the small GTPase Rho is a key regulator of MLC phosphorylation, we investigated 1) whether Rho is activated by hyperosmotic stress, and if so, what the triggering factors are, and 2) whether the Rho/Rho kinase (ROK) pathway is involved in MLC phosphorylation and NKCC activation. Rho activity was measured in tubular epithelial cells by affinity pulldown assay. Hyperosmolarity induced rapid (<1 min) and sustained (>20 min) Rho activation that was proportional to the osmotic concentration and reversed within minutes upon restoration of isotonicity. Both decreased cell volume at constant ionic strength and elevated total ionic strength at constant cell volume were capable of activating Rho. Changes in [Na+] and [K+] at normal total salinity failed to activate Rho, and Cl- depletion did not affect the hyperosmotic response. Thus alterations in cellular volume and ionic strength but not individual ion concentrations seem to be the critical triggering factors. Hyperosmolarity induced mono- and diphosphorylation of MLC, which was abrogated by the Rho-family blocker Clostridium toxin B. ROK inhibitor Y-27632 suppressed MLC phosphorylation under isotonic conditions and prevented its rise over isotonic levels in hypertonically stimulated cells. ML-7 had a smaller inhibitory effect. In contrast, it abolished the hypertonic activation of NKCC, whereas Y-27632 failed to inhibit this response. Thus hyperosmolarity activates Rho, and Rho/ROK pathway contributes to basal and hyperosmotic MLC phosphorylation. However, the hypertonic activation of NKCC is ROK independent, implying that the ROK-dependent component of MLC phosphorylation can be uncoupled from NKCC activation. PMID:12748065

  20. RhoGDI-1 modulation of the activity of monomeric RhoGTPase RhoA regulates endothelial barrier function in mouse lungs.

    PubMed

    Gorovoy, Matvey; Neamu, Radu; Niu, Jiaxin; Vogel, Stephen; Predescu, Dan; Miyoshi, Jun; Takai, Yoshimi; Kini, Vidisha; Mehta, Dolly; Malik, Asrar B; Voyno-Yasenetskaya, Tatyana

    2007-07-01

    Rho family GTPases have been implicated in the regulation of endothelial permeability via their actions on actin cytoskeletal organization and integrity of interendothelial junctions. In cell culture studies, activation of RhoA disrupts interendothelial junctions and increases endothelial permeability, whereas activation of Rac1 and Cdc42 enhances endothelial barrier function by promoting the formation of restrictive junctions. The primary regulators of Rho proteins, guanine nucleotide dissociation inhibitors (GDIs), form a complex with the GDP-bound form of the Rho family of monomeric G proteins, and thus may serve as a nodal point regulating the activation state of RhoGTPases. In the present study, we addressed the in vivo role of RhoGDI-1 in regulating pulmonary microvascular permeability using RhoGDI-1(-/-) mice. We observed that basal endothelial permeability in lungs of RhoGDI-1(-/-) mice was 2-fold greater than wild-type mice. This was the result of opening of interendothelial junctions in lung microvessels which are normally sealed. The activity of RhoA (but not of Rac1 or Cdc42) was significantly increased in RhoGDI-1(-/-) lungs as well as in cultured endothelial cells on downregulation of RhoGDI-1 with siRNA, consistent with RhoGDI-1-mediated modulation RhoA activity. Thus, RhoGDI-1 by repressing RhoA activity regulates lung microvessel endothelial barrier function in vivo. In this regard, therapies augmenting endothelial RhoGDI-1 function may be beneficial in reestablishing the endothelial barrier and lung fluid balance in lung inflammatory diseases such as acute respiratory distress syndrome. PMID:17525371

  1. Novel Rho/MRTF/SRF Inhibitors Block Matrix-stiffness and TGF-β–Induced Fibrogenesis in Human Colonic Myofibroblasts

    PubMed Central

    Johnson, Laura A.; Rodansky, Eva S.; Haak, Andrew J.; Larsen, Scott D.; Neubig, Richard R.; Higgins, Peter D. R.

    2016-01-01

    Background Ras homolog gene family, member A (RhoA)/Rho-associated coiled-coil forming protein kinase signaling is a key pathway in multiple types of solid organ fibrosis, including intestinal fibrosis. However, the pleiotropic effects of RhoA/Rho-associated coiled-coil forming protein kinase signaling have frustrated targeted drug discovery efforts. Recent recognition of the role of Rho-regulated gene transcription by serum response factor (SRF) and its transcriptional cofactor myocardin-related transcription factor A (MRTF-A) suggest a novel locus for pharmacological intervention. Methods Because RhoA signaling is mediated by both physical and biochemical stimuli, we examined whether pharmacological inhibition of RhoA or the downstream transcription pathway of MRTF-A/SRF could block intestinal fibrogenesis in 2 in vitro models. Results In this study, we demonstrate that inhibition of RhoA signaling blocks both matrix-stiffness and transforming growth factor beta–induced fibrogenesis in human colonic myofibroblasts. Repression of alpha-smooth muscle actin and collagen expression was associated with the inhibition of MRTF-A nuclear localization. CCG-1423, a first-generation Rho/MRTF/SRF pathway inhibitor, repressed fibrogenesis in both models, yet has unacceptable cytotoxicity. Novel second-generation inhibitors (CCG-100602 and CCG-203971) repressed both matrix-stiffness and transforming growth factor beta–mediated fibrogenesis as determined by protein and gene expression in a dose-dependent manner. Conclusions Targeting the Rho/MRTF/SRF mechanism with second-generation Rho/MRTF/SRF inhibitors may represent a novel approach to antifibrotic therapeutics. PMID:24280883

  2. Formins as effector proteins of Rho GTPases

    PubMed Central

    Kühn, Sonja; Geyer, Matthias

    2014-01-01

    Formin proteins were recognized as effectors of Rho GTPases some 15 years ago. They contribute to different cellular actin cytoskeleton structures by their ability to polymerize straight actin filaments at the barbed end. While not all formins necessarily interact with Rho GTPases, a subgroup of mammalian formins, termed Diaphanous-related formins or DRFs, were shown to be activated by small GTPases of the Rho superfamily. DRFs are autoinhibited in the resting state by an N- to C-terminal interaction that renders the central actin polymerization domain inactive. Upon the interaction with a GTP-bound Rho, Rac, or Cdc42 GTPase, the C-terminal autoregulation domain is displaced from its N-terminal recognition site and the formin becomes active to polymerize actin filaments. In this review we discuss the current knowledge on the structure, activation, and function of formin-GTPase interactions for the mammalian formin families Dia, Daam, FMNL, and FHOD. We describe both direct and indirect interactions of formins with GTPases, which lead to formin activation and cytoskeletal rearrangements. The multifaceted function of formins as effector proteins of Rho GTPases thus reflects the diversity of the actin cytoskeleton in cells. PMID:24914801

  3. Phylogenetic analysis of sequences from diverse bacteria with homology to the Escherichia coli rho gene.

    PubMed Central

    Opperman, T; Richardson, J P

    1994-01-01

    Genes from Pseudomonas fluorescens, Chromatium vinosum, Micrococcus luteus, Deinococcus radiodurans, and Thermotoga maritima with homology to the Escherichia coli rho gene were cloned and sequenced, and their sequences were compared with other available sequences. The species for all of the compared sequences are members of five bacterial phyla, including Thermotogales, the most deeply diverged phylum. This suggests that a rho-like gene is ubiquitous in the Bacteria and was present in their common ancestor. The comparative analysis revealed that the Rho homologs are highly conserved, exhibiting a minimum identity of 50% of their amino acid residues in pairwise comparisons. The ATP-binding domain had a particularly high degree of conservation, consisting of some blocks with sequences of residues that are very similar to segments of the alpha and beta subunits of F1-ATPase and of other blocks with sequences that are unique to Rho. The RNA-binding domain is more diverged than the ATP-binding domain. However, one of its most highly conserved segments includes a RNP1-like sequence, which is known to be involved in RNA binding. Overall, the degree of similarity is lowest in the first 50 residues (the first half of the RNA-binding domain), in the putative connector region between the RNA-binding and the ATP-binding domains, and in the last 50 residues of the polypeptide. Since functionally defective mutants for E. coli Rho exist in all three of these segments, they represent important parts of Rho that have undergone adaptive evolution. PMID:8051015

  4. Diffractive {rho}0 production at COMPASS

    SciTech Connect

    D'Hose, N.

    2005-10-06

    Diffractive leptoproduction of {rho}0 mesons, {mu} + N {yields} {mu} + N + {rho} is measured at COMPASS at < W > = 10 GeV over a wide range of Q2, 0.01 < Q2 < 10 GeV2. Angular distributions allow to determine spin density matrix elements. Preliminary results from COMPASS 2002 data are presented. They are consistent with a substantial increase of R = {sigma}L/{sigma}T with Q2 and a weak violation of SCHC, in agreement with other high energy experiments.

  5. Approaches of targeting Rho GTPases in cancer drug discovery

    PubMed Central

    Lin, Yuan; Zheng, Yi

    2016-01-01

    Introduction Rho GTPases are master regulators of actomyosin structure and dynamics and play pivotal roles in a variety of cellular processes including cell morphology, gene transcription, cell cycle progression and cell adhesion. Because aberrant Rho GTPase signaling activities are widely associated with human cancer, key components of Rho GTPase signaling pathways have attracted increasing interest as potential therapeutic targets. Similar to Ras, Rho GTPases themselves were, until recently, deemed “undruggable” because of structure-function considerations. Several approaches to interfere with Rho GTPase signaling have been explored and show promise as new ways for tackling cancer cells. Areas covered This review focuses on the recent progress in targeting the signaling activities of three prototypical Rho GTPases, i.e. RhoA, Rac1, and Cdc42. The authors describe the involvement of these Rho GTPases, their key regulators and effectors in cancer. Furthermore, the authors discuss the current approaches for rationally targeting aberrant Rho GTPases along their signaling cascades, upstream and downstream of Rho GTPases and posttranslational modifications at a molecular level. Expert opinion To date, while no clinically effective drugs targeting Rho GTPase signaling for cancer treatment are available, tool compounds and lead drugs that pharmacologically inhibit Rho GTPase pathways have shown promise. Small molecule inhibitors targeting Rho GTPase signaling may add new treatment options for future precision cancer therapy, particularly in combination with other anti-cancer agents. PMID:26087073

  6. Structural and Mechanistic Insights into the Regulation of the Fundamental Rho Regulator RhoGDIα by Lysine Acetylation.

    PubMed

    Kuhlmann, Nora; Wroblowski, Sarah; Knyphausen, Philipp; de Boor, Susanne; Brenig, Julian; Zienert, Anke Y; Meyer-Teschendorf, Katrin; Praefcke, Gerrit J K; Nolte, Hendrik; Krüger, Marcus; Schacherl, Magdalena; Baumann, Ulrich; James, Leo C; Chin, Jason W; Lammers, Michael

    2016-03-11

    Rho proteins are small GTP/GDP-binding proteins primarily involved in cytoskeleton regulation. Their GTP/GDP cycle is often tightly connected to a membrane/cytosol cycle regulated by the Rho guanine nucleotide dissociation inhibitor α (RhoGDIα). RhoGDIα has been regarded as a housekeeping regulator essential to control homeostasis of Rho proteins. Recent proteomic screens showed that RhoGDIα is extensively lysine-acetylated. Here, we present the first comprehensive structural and mechanistic study to show how RhoGDIα function is regulated by lysine acetylation. We discover that lysine acetylation impairs Rho protein binding and increases guanine nucleotide exchange factor-catalyzed nucleotide exchange on RhoA, these two functions being prerequisites to constitute a bona fide GDI displacement factor. RhoGDIα acetylation interferes with Rho signaling, resulting in alteration of cellular filamentous actin. Finally, we discover that RhoGDIα is endogenously acetylated in mammalian cells, and we identify CBP, p300, and pCAF as RhoGDIα-acetyltransferases and Sirt2 and HDAC6 as specific deacetylases, showing the biological significance of this post-translational modification. PMID:26719334

  7. Rho GTPases at the crossroad of signaling networks in mammals

    PubMed Central

    Wojnacki, José; Quassollo, Gonzalo; Marzolo, María-Paz; Cáceres, Alfredo

    2014-01-01

    Microtubule (MT) organization and dynamics downstream of external cues is crucial for maintaining cellular architecture and the generation of cell asymmetries. In interphase cells RhoA, Rac, and Cdc42, conspicuous members of the family of small Rho GTPases, have major roles in modulating MT stability, and hence polarized cell behaviors. However, MTs are not mere targets of Rho GTPases, but also serve as signaling platforms coupling MT dynamics to Rho GTPase activation in a variety of cellular conditions. In this article, we review some of the key studies describing the reciprocal relationship between small Rho-GTPases and MTs during migration and polarization. PMID:24691223

  8. Measurements of branching fraction, polarization, and charge asymmetry of B(+/-)-->rho(+/-)rho(0) and a search for B(+/-)-->rho(+/-)f(0)(980).

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Sanchez, P Del Amo; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Vetere, M Lo; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Vazquez, W Panduro; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Lodovico, F Di; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; Del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Tehrani, F Safai; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; Macfarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2006-12-31

    We measure the branching fraction (B), polarization (f(L)), and CP asymmetry (A(CP)) of B(+/-)-->rho(+/-)rho(0) decays and search for the decay B(+/-)-->rho(+/-)f(0)(980) based on a data sample of 231.8 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B factory. In B(+/-)-->rho(+/-)rho(0) decays we measure B=(16.8+/-2.2+/-2.3) x 10(-), f(L)=0.905+/-0.042(-0.027)(+0.023), and A(CP)=-0.12+/-0.13+/-0.10, and find an upper limit on the branching fraction of B(+/-)-->rho(+/-)f(0)(980)(-->pi(+)pi(-)) decays of 1.9 x 10(-6) at 90% confidence level. PMID:17280416

  9. RhoA GTPase inhibition organizes contraction during epithelial morphogenesis.

    PubMed

    Mason, Frank M; Xie, Shicong; Vasquez, Claudia G; Tworoger, Michael; Martin, Adam C

    2016-08-29

    During morphogenesis, contraction of the actomyosin cytoskeleton within individual cells drives cell shape changes that fold tissues. Coordination of cytoskeletal contractility is mediated by regulating RhoA GTPase activity. Guanine nucleotide exchange factors (GEFs) activate and GTPase-activating proteins (GAPs) inhibit RhoA activity. Most studies of tissue folding, including apical constriction, have focused on how RhoA is activated by GEFs to promote cell contractility, with little investigation as to how GAPs may be important. Here, we identify a critical role for a RhoA GAP, Cumberland GAP (C-GAP), which coordinates with a RhoA GEF, RhoGEF2, to organize spatiotemporal contractility during Drosophila melanogaster apical constriction. C-GAP spatially restricts RhoA pathway activity to a central position in the apical cortex. RhoGEF2 pulses precede myosin, and C-GAP is required for pulsation, suggesting that contractile pulses result from RhoA activity cycling. Finally, C-GAP expression level influences the transition from reversible to irreversible cell shape change, which defines the onset of tissue shape change. Our data demonstrate that RhoA activity cycling and modulating the ratio of RhoGEF2 to C-GAP are required for tissue folding. PMID:27551058

  10. Interaction of Anesthetics with the Rho GTPase Regulator Rho GDP Dissociation Inhibitor†

    PubMed Central

    Ho, Cojen; Shanmugasundararaj, Sivananthaperumal; Miller, Keith W.; Malinowski, Steve A.; Cook, Anthony C.; Slater, Simon J.

    2015-01-01

    The physiological effects of anesthetics have been ascribed to their interaction with hydrophobic sites within functionally relevant CNS proteins. Studies have shown that volatile anesthetics compete for luciferin binding to the hydrophobic substrate binding site within firefly luciferase and inhibit its activity (Franks, N. P., and Lieb, W. R. (1984) Nature 310, 599–601). To assess whether anesthetics also compete for ligand binding to a mammalian signal transduction protein, we investigated the interaction of the volatile anesthetic, halothane, with the Rho GDP dissociation inhibitor (RhoGDIα), which binds the geranylgeranyl moiety of GDP-bound Rho GTPases. Consistent with the existence of a discrete halothane binding site, the intrinsic tryptophan fluorescence of RhoGDIα was quenched by halothane (2-bromo-2-chloro-1,1,1-trifluoroethane) in a saturable, concentration-dependent manner. Bromine quenching of tryptophan fluorescence is short range and W192 and W194 of the RhoGDIα are located within the geranylgeranyl binding pocket, suggesting that halothane binds within this region. Supporting this, N-acetyl-geranylgeranyl cysteine reversed tryptophan quenching by halothane. Short chain n-alcohols (n<6) also reversed tryptophan quenching, suggesting that RhoGDIα may also bind n-alkanols. Consistent with this, E193 was photo-labeled by 3-azibutanol. This residue is located in the vicinity of, but outside, the geranylgeranyl chain binding pocket, suggesting that the alcohol binding site is distinct from that occupied by halothane. Supporting this, N-acetyl-geranylgeranyl cysteine enhanced E193 photo-labeling by 3-azibutanol. Overall, the results suggest that halothane binds to a site within the geranylgeranyl chain binding pocket of RhoGDIα, whereas alcohols bind to a distal site that interacts allosterically with this pocket. PMID:18702520

  11. Rho Signaling Participates in Membrane Fluidity Homeostasis

    PubMed Central

    Lockshon, Daniel; Olsen, Carissa Perez; Brett, Christopher L.; Chertov, Andrei; Merz, Alexey J.; Lorenz, Daniel A.; Van Gilst, Marc R.; Kennedy, Brian K.

    2012-01-01

    Preservation of both the integrity and fluidity of biological membranes is a critical cellular homeostatic function. Signaling pathways that govern lipid bilayer fluidity have long been known in bacteria, yet no such pathways have been identified in eukaryotes. Here we identify mutants of the yeast Saccharomyces cerevisiae whose growth is differentially influenced by its two principal unsaturated fatty acids, oleic and palmitoleic acid. Strains deficient in the core components of the cell wall integrity (CWI) pathway, a MAP kinase pathway dependent on both Pkc1 (yeast's sole protein kinase C) and Rho1 (the yeast RhoA-like small GTPase), were among those inhibited by palmitoleate yet stimulated by oleate. A single GEF (Tus1) and a single GAP (Sac7) of Rho1 were also identified, neither of which participate in the CWI pathway. In contrast, key components of the CWI pathway, such as Rom2, Bem2 and Rlm1, failed to influence fatty acid sensitivity. The differential influence of palmitoleate and oleate on growth of key mutants correlated with changes in membrane fluidity measured by fluorescence anisotropy of TMA-DPH, a plasma membrane-bound dye. This work provides the first evidence for the existence of a signaling pathway that enables eukaryotic cells to control membrane fluidity, a requirement for division, differentiation and environmental adaptation. PMID:23071506

  12. Horse chestnut extract induces contraction force generation in fibroblasts through activation of Rho/Rho kinase.

    PubMed

    Fujimura, Tsutomu; Moriwaki, Shigeru; Hotta, Mitsuyuki; Kitahara, Takashi; Takema, Yoshinori

    2006-06-01

    Contraction forces generated by non-muscle cells such as fibroblasts play important roles in determining cell morphology, vasoconstriction, and/or wound healing. However, few factors that induce cell contraction forces are known, such as lysophosphatidic acid and thrombin. Our study analyzed various plant extracts for ingredients that induce generation of cell contraction forces in fibroblasts populating collagen gels. We found that an extract of Horse chestnut (Aesculus hippocastanum) is able to induce such contraction forces in fibroblasts. The involvement of actin polymerization and stress fiber formation in the force generation was suggested by inhibition of this effect by cytochalasin D and by Rhodamine phalloidin. Rho kinase inhibitors (Y27632 and HA1077) and a Rho inhibitor (exoenzyme C3) significantly inhibited the force generation induced by the Horse chestnut extract. H7, which inhibits Rho kinase as well as other protein kinases, also significantly inhibited induction of force generation. However, inhibitors of other protein kinases such as myosin light chain kinase (ML-9), protein kinase C (Calphostin), protein kinase A (KT5720), and tyrosine kinase (Genistein, Herbimycin A) had no effect on force generation induced by Horse chestnut extract. These results suggest that the Horse chestnut extract induces generation of contraction forces in fibroblasts through stress fiber formation followed by activation of Rho protein and Rho kinase but not myosin light chain kinase or other protein kinases. PMID:16754996

  13. The new Be-type star HD 147196 in the Rho Ophiuchi dark cloud region

    NASA Technical Reports Server (NTRS)

    The, P. S.; Perez, M. R.; De Winter, D.; Van Den Ancker, M. E.

    1993-01-01

    The newly discovered hot-emission line star, HD 147196 in the Rho Oph dark cloud region was observed spectroscopically and photometrically and high and low resolution IUE spectra were obtained. The finding of Irvine (1990) that this relatively bright star show its H-alpha-line in emission is confirmed. Previous H-alpha-surveys of the Rho Oph star-forming region did not detect HD 147196 as an H-alpha-emission star, meaning that it must recently be very active and has perhaps transformed itself from a B-type star at shell phase to a Be-phase. The Mg II h + k resonance lines are in absorption and they appear to be interstellar in nature, which means that either the abundance of Mg in the extended atmosphere of the star is low or that the shell is not extended enough to produce emission lines of Mg II. Photometric observations of this B8 V type star do not show any variations during at least the years covered by our monitoring or any excess of NIR radiation in its spectral energy distribution up to the M-passband at 4.8 microns.

  14. Crocetin ester improves myocardial ischemia via Rho/ROCK/NF-κB pathway.

    PubMed

    Huang, Zhiheng; Nan, Chen; Wang, Hanqing; Su, Qiang; Xue, Wenda; Chen, Yanyan; Shan, Xin; Duan, Jinao; Chen, Gang; Tao, Weiwei

    2016-09-01

    Crocetin ester (CE) is the active ingredient of Crocus sativus L. stigmas and Gardenia jasminoides Ellis fruit. The main purpose of the present study was to investigate the protective effect of CE on isoproterenol (ISO)-induced acute myocardial ischemia (AMI) through Rho/ROCK/NF-κB pathway and explore its underlying mechanism. Administration of CE (25 and 50mg/kg) could significantly reduce the serum contents of pro-inflammatory cytokines including tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6). In addition, pretreatment with CE attenuated the contents of creatine kinase (CK), malondialdehyde (MDA) and the activities of lactate dehydrogenase (LDH), superoxide dismutase (SOD) in serum. Treatment with CE also improved the histopathological alteration and decreased the ST elevation. Furthermore, CE could ameliorate the cardiac expressions of Cu, Zn-superoxide dismutase (SOD1), MDA5, Rho, ROCK, p-IκB and p-NF-κBp65 in ISO-induced rats. It was assumed that CE might be a new therapeutic candidate for the treatment of AMI possibly through the inhibition of Rho/ROCK/NF-κB pathway. PMID:27285672

  15. Molecular mechanism for the regulation of rho-kinase by dimerization and its inhibition by fasudil.

    PubMed

    Yamaguchi, Hiroto; Kasa, Miyuki; Amano, Mutsuki; Kaibuchi, Kozo; Hakoshima, Toshio

    2006-03-01

    Rho-kinase is a key regulator of cytoskeletal events and a promising drug target in the treatment of vascular diseases and neurological disorders. Unlike other protein kinases, Rho-kinase requires both N- and C-terminal extension segments outside the kinase domain for activity, although the details of this requirement have been elusive. The crystal structure of an active Rho-kinase fragment containing the kinase domain and both the extensions revealed a head-to-head homodimer through the N-terminal extension forming a helix bundle that structurally integrates the C-terminal extension. This structural organization enables binding of the C-terminal hydrophobic motif to the N-terminal lobe, which defines the correct disposition of helix alphaC that is important for the catalytic activity. The bound inhibitor fasudil significantly alters the conformation and, consequently, the mode of interaction with the catalytic cleft that contains local structural changes. Thus, both kinase and drug conformational pliability and stability confer selectivity. PMID:16531242

  16. rho/sup 0/. omega. production in photon photon interactions

    SciTech Connect

    Derby, K.A.

    1987-08-01

    The subject of this dissertation is the production of the rho/sup 0/..omega.. final state in photon photon interactions. The production of the rho/sup 0/..omega.. final state has been of interest primarily because of its similarity to the related process ..gamma gamma.. ..-->.. rho/sup 0/rho/sup 0/. The cross section for rho/sup 0/rho/sup 0/ production demonstrates a peaking near threshold, the mechanism of which has been the subject of considerable speculation. The data sample used for the analysis was obtained using the TPC detector facility at the PEP e/sup +/e/sup -/ storage ring, and corresponds to an integrated e/sup +/e/sup -/ luminosity of 64 pb/sup -1/ at 29 GeV center of mass energy. Our estimate of the rho/sup 0/..omega.. cross section is compared to the predictions of several models which have been used to account for the observed rho/sup 0/rho/sup 0/ cross section. The experimental results are consistent with the predictions of a threshold enhancement model, as well as those of a four quark (qq anti q anti q) resonance model. However, they disagree with the predictions of a t-channel factorization approach.

  17. Neutral Rho Omega Production in Photon Photon Interactions.

    NASA Astrophysics Data System (ADS)

    Derby, Kevin Arthur

    1987-09-01

    The subject of this dissertation is the production of the rho^0omega final state in photon photon interactions. The production of the rho^0omega final state has been of interest primarily because of its similarity to the related process gammagamma to rho^0rho ^0. The cross section for rho ^0rho^0 production demonstrates a peaking near threshold, the mechanism of which has been the subject of considerable speculation. The data sample used for the analysis was obtained using the TPC detector facility at the PEP e^+e^- storage ring and corresponds to an integrated e ^+e^- luminosity of 64 pb ^{-1} at 29 GeV center of mass energy. Our estimate of the rho^0 omega cross section is compared to the predictions of several models which have been used to account for the observed rho^0rho^0 cross section. The experimental results are consistent with the predictions of a threshold enhancement model as well as those of a four quark (qqqq) resonance model. However, they disagree with the predictions of a t-channel factorization approach.

  18. Rho kinase as a target for cerebral vascular disorders

    PubMed Central

    Bond, Lisa M; Sellers, James R; McKerracher, Lisa

    2015-01-01

    The development of novel pharmaceutical treatments for disorders of the cerebral vasculature is a serious unmet medical need. These vascular disorders are typified by a disruption in the delicate Rho signaling equilibrium within the blood vessel wall. In particular, Rho kinase overactivation in the smooth muscle and endothelial layers of the vessel wall results in cytoskeletal modifications that lead to reduced vascular integrity and abnormal vascular growth. Rho kinase is thus a promising target for the treatment of cerebral vascular disorders. Indeed, preclinical studies indicate that Rho kinase inhibition may reduce the formation/growth/rupture of both intracranial aneurysms and cerebral cavernous malformations. PMID:26062400

  19. Pattern formation of Rho GTPases in single cell wound healing

    PubMed Central

    Simon, Cory M.; Vaughan, Emily M.; Bement, William M.; Edelstein-Keshet, Leah

    2013-01-01

    The Rho GTPases—Rho, Rac, and Cdc42—control an enormous variety of processes, many of which reflect activation of these GTPases in spatially confined and mutually exclusive zones. By using mathematical models and experimental results to establish model parameters, we analyze the formation and segregation of Rho and Cdc42 zones during Xenopus oocyte wound repair and the role played by Abr, a dual guanine nucleotide exchange factor–GTPase-activating protein, in this process. The Rho and Cdc42 zones are found to be best represented as manifestations of spatially modulated bistability, and local positive feedback between Abr and Rho can account for the maintenance and dynamic properties of the Rho zone. In contrast, the invocation of an Abr-independent positive feedback loop is required to account for Cdc42 spatial bistability. In addition, the model replicates the results of previous in vivo experiments in which Abr activity is manipulated. Further, simulating the model with two closely spaced wounds made nonintuitive predictions about the Rho and Cdc42 patterns; these predictions were confirmed by experiment. We conclude that the model is a useful tool for analysis of Rho GTPase signaling and that the Rho GTPases can be fruitfully considered as components of intracellular pattern formation systems. PMID:23264464

  20. Search for medium modifications of the rho meson.

    PubMed

    Nasseripour, R; Wood, M H; Djalali, C; Weygand, D P; Tur, C; Mosel, U; Muehlich, P; Adams, G; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Barrow, S; Battaglieri, M; Bedlinskiy, I; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Biselli, A S; Blaszczyk, L; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Butuceanu, C; Calarco, J R; Careccia, S L; Carman, D S; Carnahan, B; Casey, L; Chen, S; Cole, P L; Collins, P; Coltharp, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; Dashyan, N; De Masi, R; De Vita, R; De Sanctis, E; Degtyarenko, P V; Denizli, H; Dennis, L; Deur, A; Dharmawardane, K V; Dickson, R; Dodge, G E; Doughty, D; Dugger, M; Dytman, S; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Feldman, G; Feuerbach, R J; Funsten, H; Garçon, M; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Goetz, J T; Gordon, C I O; Gothe, R W; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde-Wright, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kalantarians, N; Kellie, J D; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Kossov, M; Krahn, Z; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Li, Ji; Livingston, K; Lu, H Y; Maccormick, M; Markov, N; Mattione, P; McAleer, S; McKinnon, B; McNabb, J W C; Mecking, B A; Mehrabyan, S; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Minehart, R; Mirazita, M; Miskimen, R; Mokeev, V; Moriya, K; Morrow, S A; Moteabbed, M; Mueller, J; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Pasyuk, E; Paterson, C; Anefalos Pereira, S; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rosner, G; Rossi, P; Sabatié, F; Salamanca, J; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Stavinsky, A; Stepanyan, S S; Stepanyan, S; Stokes, B E; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Tkabladze, A; Tkachenko, S; Todor, L; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Weinstein, L B; Williams, M; Wolin, E; Yegneswaran, A; Zana, L; Zhang, B; Zhang, J; Zhao, B; Zhao, Z W

    2007-12-31

    The photoproduction of vector mesons on various nuclei has been studied using the CLAS detector at Jefferson Laboratory. The vector mesons, rho, omega, and varphi, are observed via their decay to e;{+}e;{-}, in order to reduce the effects of final-state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the rho meson. The rho mass spectrum is extracted from the data on various nuclei, 2H, C, Fe, and Ti. We observe no significant mass shift and some broadening consistent with expected collisional broadening for the rho meson. PMID:18233570

  1. Functional Cross-talk between Ras and Rho Pathways

    PubMed Central

    Jaiswal, Mamta; Dvorsky, Radovan; Amin, Ehsan; Risse, Sarah L.; Fansa, Eyad K.; Zhang, Si-Cai; Taha, Mohamed S.; Gauhar, Aziz R.; Nakhaei-Rad, Saeideh; Kordes, Claus; Koessmeier, Katja T.; Cirstea, Ion C.; Olayioye, Monilola A.; Häussinger, Dieter; Ahmadian, Mohammad R.

    2014-01-01

    The three deleted in liver cancer genes (DLC1–3) encode Rho-specific GTPase-activating proteins (RhoGAPs). Their expression is frequently silenced in a variety of cancers. The RhoGAP activity, which is required for full DLC-dependent tumor suppressor activity, can be inhibited by the Src homology 3 (SH3) domain of a Ras-specific GAP (p120RasGAP). Here, we comprehensively investigated the molecular mechanism underlying cross-talk between two distinct regulators of small GTP-binding proteins using structural and biochemical methods. We demonstrate that only the SH3 domain of p120 selectively inhibits the RhoGAP activity of all three DLC isoforms as compared with a large set of other representative SH3 or RhoGAP proteins. Structural and mutational analyses provide new insights into a putative interaction mode of the p120 SH3 domain with the DLC1 RhoGAP domain that is atypical and does not follow the classical PXXP-directed interaction. Hence, p120 associates with the DLC1 RhoGAP domain by targeting the catalytic arginine finger and thus by competitively and very potently inhibiting RhoGAP activity. The novel findings of this study shed light on the molecular mechanisms underlying the DLC inhibitory effects of p120 and suggest a functional cross-talk between Ras and Rho proteins at the level of regulatory proteins. PMID:24443565

  2. Rho Ophiuchi Cloud Core Extinction Map

    NASA Astrophysics Data System (ADS)

    Gibson, D. J.; Rudolph, A.; Barsony, M.

    1997-12-01

    We present an extinction map of a one square degree region ( ~ 2.2pc square) of the core of the star-forming region rho Ophiuchi derived by the method of star counts. Photometry from the near-infrared J, H, and K band images of Barsony et al. (1997) provided the stellar catalog for this study. From this map an estimate of the mass of the region is made and compared with previous estimates from other methods. Reference Barsony, M., Kenyon, S.J., Lada, E.A., & Teuben, P.J. 1997, ApJS, 112, 109

  3. Insights into the Molecular Activation Mechanism of the RhoA-specific Guanine Nucleotide Exchange Factor, PDZRhoGEF

    SciTech Connect

    Bielnicki, Jakub A.; Shkumatov, Alexander V.; Derewenda, Urszula; Somlyo, Avril V.; Svergun, Dmitri I.; Derewenda, Zygmunt S.

    2012-10-09

    PDZRhoGEF (PRG) belongs to a small family of RhoA-specific nucleotide exchange factors that mediates signaling through select G-protein-coupled receptors via G{alpha}{sub 12/13} and activates RhoA by catalyzing the exchange of GDP to GTP. PRG is a multidomain protein composed of PDZ, regulators of G-protein signaling-like (RGSL), Dbl-homology (DH), and pleckstrin-homology (PH) domains. It is autoinhibited in cytosol and is believed to undergo a conformational rearrangement and translocation to the membrane for full activation, although the molecular details of the regulation mechanism are not clear. It has been shown recently that the main autoregulatory elements of PDZRhoGEF, the autoinhibitory 'activation box' and the 'GEF switch,' which is required for full activation, are located directly upstream of the catalytic DH domain and its RhoA binding surface, emphasizing the functional role of the RGSL-DH linker. Here, using a combination of biophysical and biochemical methods, we show that the mechanism of PRG regulation is yet more complex and may involve an additional autoinhibitory element in the form of a molten globule region within the linker between RGSL and DH domains. We propose a novel, two-tier model of autoinhibition where the activation box and the molten globule region act synergistically to impair the ability of RhoA to bind to the catalytic DH-PH tandem. The molten globule region and the activation box become less ordered in the PRG-RhoA complex and dissociate from the RhoA-binding site, which may constitute a critical step leading to PRG activation.

  4. Observation of e+e- Annihilations into the C=+1 Hadronic Final States \\rho^0\\rho^0 and \\phi\\rho^0

    SciTech Connect

    Aubert, B.

    2006-06-27

    The authors report the first observation of e{sup +}e{sup -} annihilations into states of positive C-parity, namely {rho}{sup 0}{rho}{sup 0} and {phi}{rho}{sup 0}. The two states are observed in the {pi}{sup +}{pi}{sup -}{pi}{sup +}{pi}{sup -} and K{sup +}K{sup -} {pi}{sup +}{pi}{sup -} final states, respectively, in a data sample of 225 fb{sup -1} collected by the BABAR experiment at the PEP-II e{sup +}e{sup -} storage rings at energies near {radical}s = 10.58 GeV. The distributions of cos {theta}*, where {theta}* is the center-of-mass polar angle of the {phi} meson or the forward {rho}{sup 0} meson, suggest production by two-virtual-photon annihilation. They measure cross sections within the range |cos {theta}*| < 0.8 of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup 0} {rho}{sup 0}) = 20.7 {+-} 0.7(stat) {+-} 2.7(syst) fb and {sigma}(e{sup +}e{sup -} {yields} {phi}{rho}{sup 0}) = 5.7 {+-} 0.5(stat) {+-} 0.8(syst) fb.

  5. Regulation of phagocytosis by Rho GTPases

    PubMed Central

    Mao, Yingyu; Finnemann, Silvia C

    2015-01-01

    Phagocytosis is defined as a cellular uptake pathway for particles of greater than 0.5 μm in diameter. Particle clearance by phagocytosis is of critical importance for tissue health and homeostasis. The ultimate goal of anti-pathogen phagocytosis is to destroy engulfed bacteria or fungi and to stimulate cell-cell signaling that mount an efficient immune defense. In contrast, clearance phagocytosis of apoptotic cells and cell debris is anti-inflammatory. High capacity clearance phagocytosis pathways are available to professional phagocytes of the immune system and the retina. Additionally, a low capacity, so-called bystander phagocytic pathway is available to most other cell types. Different phagocytic pathways are stimulated by particle ligation of distinct surface receptors but all forms of phagocytosis require F-actin recruitment beneath tethered particles and F-actin re-arrangement promoting engulfment, which are controlled by Rho family GTPases. The specificity of Rho GTPase activity during the different forms of phagocytosis by mammalian cells is the subject of this review. PMID:25941749

  6. StARD13(Dlc-2) RhoGap mediates ceramide activation of phosphatidylglycerolphosphate synthase and drug response in Chinese hamster ovary cells.

    PubMed

    Hatch, Grant M; Gu, Yuan; Xu, Fred Y; Cizeau, Jeannick; Neumann, Shannon; Park, Ji-Seon; Loewen, Shauna; Mowat, Michael R A

    2008-03-01

    To identify genes involved in etoposide drug response, we used promoter trap mutagenesis to isolate an etoposide-resistant Chinese hamster ovary (CHO) cell line. This resistant CHO-K1 line, named E91, showed cross-resistance to C(2)-ceramide (N-acetylsphingosine). The promoter trap retrovirus was found integrated into intron 1-2 of the Dlc-2 (Stard13) RhoGap gene. The E91 cells showed elevated guanosine triphosphate (GTP)-bound RhoA levels compared with the parental line, suggesting that retrovirus integration had inactivated one of the Dlc-2 RhoGap alleles. To test whether E91 cells were impaired in an intracellular ceramide-regulated process not directly related to cell killing, we measured mitochondrial phosphatidylglycerolphosphate (PGP) synthase and phospholipase A2 enzyme activities in cells after C(2)-ceramide addition. Parental cells showed elevated enzyme activities after treatment with C(2)-ceramide or tumor necrosis factor alpha, but not the E91 cells. These results suggested that intracellular ceramide signaling was defective in E91 cells due to increased levels of active GTP-bound RhoA. RNA knockdown experiments of the Dlc2 RhoGap resulted in increased GTP-bound RhoA and reduced induction of PGP synthase after C(2)-ceramide addition compared with controls. Expression of a dominant-negative RhoA in the E91 cell line allowed induction of PGP synthase by ceramide. The RNA interference knockdown cell line also showed increased etoposide resistance. This study is the first report for the regulation of a phospholipid biosynthetic enzyme through RhoGap expression. PMID:18162584

  7. Spatiotemporal analysis of RhoA/B/C activation in primary human endothelial cells

    PubMed Central

    Reinhard, Nathalie R.; van Helden, Suzanne F.; Anthony, Eloise C.; Yin, Taofei; Wu, Yi I.; Goedhart, Joachim; Gadella, Theodorus W. J.; Hordijk, Peter L.

    2016-01-01

    Endothelial cells line the vasculature and are important for the regulation of blood pressure, vascular permeability, clotting and transendothelial migration of leukocytes and tumor cells. A group of proteins that that control the endothelial barrier function are the RhoGTPases. This study focuses on three homologous (>88%) RhoGTPases: RhoA, RhoB, RhoC of which RhoB and RhoC have been poorly characterized. Using a RhoGTPase mRNA expression analysis we identified RhoC as the highest expressed in primary human endothelial cells. Based on an existing RhoA FRET sensor we developed new RhoB/C FRET sensors to characterize their spatiotemporal activation properties. We found all these RhoGTPase sensors to respond to physiologically relevant agonists (e.g. Thrombin), reaching transient, localized FRET ratio changes up to 200%. These RhoA/B/C FRET sensors show localized GEF and GAP activity and reveal spatial activation differences between RhoA/C and RhoB. Finally, we used these sensors to monitor GEF-specific differential activation of RhoA/B/C. In summary, this study adds high-contrast RhoB/C FRET sensors to the currently available FRET sensor toolkit and uncover new insights in endothelial and RhoGTPase cell biology. This allows us to study activation and signaling by these closely related RhoGTPases with high spatiotemporal resolution in primary human cells. PMID:27147504

  8. Spatiotemporal analysis of RhoA/B/C activation in primary human endothelial cells.

    PubMed

    Reinhard, Nathalie R; van Helden, Suzanne F; Anthony, Eloise C; Yin, Taofei; Wu, Yi I; Goedhart, Joachim; Gadella, Theodorus W J; Hordijk, Peter L

    2016-01-01

    Endothelial cells line the vasculature and are important for the regulation of blood pressure, vascular permeability, clotting and transendothelial migration of leukocytes and tumor cells. A group of proteins that that control the endothelial barrier function are the RhoGTPases. This study focuses on three homologous (>88%) RhoGTPases: RhoA, RhoB, RhoC of which RhoB and RhoC have been poorly characterized. Using a RhoGTPase mRNA expression analysis we identified RhoC as the highest expressed in primary human endothelial cells. Based on an existing RhoA FRET sensor we developed new RhoB/C FRET sensors to characterize their spatiotemporal activation properties. We found all these RhoGTPase sensors to respond to physiologically relevant agonists (e.g. Thrombin), reaching transient, localized FRET ratio changes up to 200%. These RhoA/B/C FRET sensors show localized GEF and GAP activity and reveal spatial activation differences between RhoA/C and RhoB. Finally, we used these sensors to monitor GEF-specific differential activation of RhoA/B/C. In summary, this study adds high-contrast RhoB/C FRET sensors to the currently available FRET sensor toolkit and uncover new insights in endothelial and RhoGTPase cell biology. This allows us to study activation and signaling by these closely related RhoGTPases with high spatiotemporal resolution in primary human cells. PMID:27147504

  9. Rho GEFs and GAPs: Emerging integrators of extracellular matrix signaling

    PubMed Central

    Kutys, Matthew L; Yamada, Kenneth M

    2015-01-01

    Investigating cell migration in 3D settings has revealed that specific extracellular matrix environments require differential activities of the Rho GTPases for efficient migration. However, it is largely unknown how the activities of specific Rho GTPases are modulated to direct cell migration in response to different extracellular matrix cues. We have recently reported that extracellular matrix-dependent regulation of a specific Rho GEF is a fundamental mechanism governing cell migration in different microenvironments, providing a direct mechanism for extracellular matrix-specific regulation of Rho GTPase activity directing cell motility. We discovered that the Rho GEF βPix has a unique function during cell migration in fibrillar collagen environments by restraining RhoA signaling through a conserved signaling axis involving Cdc42 and the Rho GAP srGAP1. In this Commentary, we expand upon this new pathway and discuss potential mechanotransductive and therapeutic applications. Additionally, we speculate on a generalized role for Rho GEFs and GAPs in providing localized, context-dependent responses to the cellular microenvironment during cell migration and other cellular processes. PMID:25862162

  10. RhoA Controls Wnt Upregulation on Microstructured Titanium Surfaces

    PubMed Central

    Mazzotta, Silvia; Piergianni, Maddalena; Piemontese, Marilina; Passeri, Giovanni

    2014-01-01

    Rough topography enhances the activation of Wnt canonical signaling in vitro, and this mediates its effects on cell differentiation. However, the molecular mechanisms underlying topography-dependent control of Wnt signaling are still poorly understood. As the small GTPase RhoA controls cytoskeletal reorganization and actomyosin-induced tensional forces, we hypothesized that RhoA could affect the activation of Wnt signaling in cells on micropatterned titanium surfaces. G-LISA assay revealed that RhoA activation was higher in C2C12 cells on rough (SLA) surfaces under basal conditions than on smooth (Polished) titanium. Transfection with dominant negative RhoA decreased Wnt activation by normalized TCF-Luc activity on SLA, whilst transfection with constitutively active RhoA increased TCF-Luc activation on Polished titanium. One mM Myosin II inhibitor Blebbistatin increased RhoA activation but decreased Wnt activation on SLA surfaces, indicating that tension-generating structures are required for canonical Wnt modulation on titanium surfaces. Actin inhibitor Cytochalasin markedly enhanced RhoA and TCF-Luc activation on both surfaces and increased the expression of differentiation markers in murine osteoblastic MC3T3 cells. Taken together, these data show that RhoA is upregulated in cells on rough surfaces and it affects the activation of Wnt canonical signaling through Myosin II modulation. PMID:24949442

  11. Study of Branching Fractions and CP-Violating Asymmetries in B Meson Decays to Rho And Pion Final State with the BABAR Detector

    SciTech Connect

    Wu, Jinwei; /Wisconsin U., Madison

    2006-03-22

    We present measurements of branching fractions and CP-violating asymmetries in B-meson decays to {rho}{sup +}{pi}{sup 0}, {rho}{sup 0}{pi}{sup +} and {rho}{sup 0}{pi}{sup 0}. The data sample comprises 89 x 10{sup 6} {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the charge-averaged branching fractions {Beta}(B{sup +} {yields} {rho}{sup +}{pi}{sup 0}) = (10.9 {+-} 1.9(stat) {+-} 1.9(syst)) x 10{sup -6} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{pi}{sup +}) = (9.5 {+-} 1.1 {+-} 0.9) x 10{sup -6}, and we set a 90% confidence-level upper limit {Beta}(B{sup 0} {yields} {rho}{sup 0}{pi}{sup 0}) < 2.9 x 10{sup -6}. We measure the charge asymmetries A{sub CP}{rho}{sup +}{pi}{sup 0} = 0.24 {+-} 0.16 {+-} 0.06 and {Alpha}{sub CP}{sup {rho}{sup 0}{pi}{sup +}} = -0.19 {+-} 0.11 {+-} 0.02. We also present the preliminary measurement of CP-violating asymmetries in B{sup 0} {yields} ({rho}{pi}){sup 0} {yields} {pi}{sup +}{pi}{sup -}{pi}{sup 0} decays using a time-dependent Dalitz plot analysis. The results are obtained from a data sample of 213 million {Upsilon}(4S) {yields} B{bar B} decays, collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. This analysis extends the narrow-{rho} quasi-two-body approximation used in the previous analysis, by taking into account the interference between the {rho} resonances of the three charges. We measure 16 coefficients of the bilinear form factor terms occurring in the time-dependent decay rate of the B{sup 0} meson with the use of a maximum-likelihood fit. We derive the physically relevant quantities from these coefficients. We measure the direct CP-violation parameters {Alpha}{sub {rho}{pi}} = -0.088 {+-} 0.049 {+-} 0.013 and C = 0.34 {+-} 0.11 {+-} 0.05, where the first errors are statistical and the second systematic. For the mixing-induced CP-violation parameter we find S = -0.10 {+-} 0.14 {+-} 0.04, and for the dilution and

  12. miR-25 promotes hepatocellular carcinoma cell growth, migration and invasion by inhibiting RhoGDI1

    PubMed Central

    Wang, Congren; Wang, Xuejin; Su, Zijian; Fei, Hongjiang; Liu, Xiaoyu; Pan, Qunxiong

    2015-01-01

    MicroRNA (miRNA)-25 is a small non-coding RNA that has been implicated in the tumorigenesis of many cancers, but little is known on the role of miR-25 in HCC metastasis. We hereby found that miR-25 was significantly upregulated in clinical HCC tissues compared with normal liver tissues. We also revealed that miR-25 dramatically stimulates HCC cell growth and activates the epithelial-mesenchymal transition (EMT). MiR-25 is activated by the WNT/β-catenin signaling pathway, and exerts its pro-metastatic function by directly inhibiting the Rho GDP dissociation inhibitor alpha (RhoGDI1). Downregulation of RhoGDI1 enhances expression of Snail, thereby promoting EMT. MiR-25 levels are positively correlated with β-catenin expression, whereas negatively correlated with the level of RhoGDI1 in HCC. Our findings provide new insights into the role of miR-25 in HCC metastasis, and implicate the potential application of miR-25 in HCC therapy. PMID:26460549

  13. Hadronic particles made of multi-{rho}(770) mesons

    SciTech Connect

    Roca, L.; Oset, E.; Yamagata-Sekihara, J.

    2011-10-21

    We summarize the work [1] where we studied the few body system made of several {rho}(770) mesons. Based on the very strong interaction of two {rho}(770) vector mesons in spin 2 and isospin 0, we show that the resonances {rho}3(1690)(3{sup --}), f4(2050)(4{sup ++}), {rho}5(2350)(5{sup --}) and f6(2510)(6{sup ++}) can be interpreted as few body systems made of an increasing number of {rho}(770) particles. The fixed center approximation of the Faddeev equations is used in order to write the multi-body interaction in terms of the elementary two-body scattering amplitudes. Very good agreement with the experimental masses is found. An extension of the model to include also the interaction with K*(895) is discussed.

  14. Alpha Particle

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Term that is sometimes used to describe a helium nucleus, a positively charged particle that consists of two protons and two neutrons, bound together. Alpha particles, which were discovered by Ernest Rutherford (1871-1937) in 1898, are emitted by atomic nuclei that are undergoing alpha radioactivity. During this process, an unstable heavy nucleus spontaneously emits an alpha particle and transmut...

  15. Testing the dynamics of B{yields}{pi}{pi} and constraints on {alpha}

    SciTech Connect

    Grossman, Yuval; Hoecker, Andreas; Ligeti, Zoltan; Pirjol, Dan

    2005-11-01

    In charmless nonleptonic B decays to {pi}{pi} or {rho}{rho}, the 'color allowed' and 'color suppressed' tree amplitudes can be studied in a systematic expansion in {alpha}{sub s}(m{sub b}) and {lambda}{sub QCD}/m{sub b}. At leading order in this expansion their relative strong phase vanishes. The implications of this prediction are obscured by penguin contributions. We propose to use this prediction to test the relative importance of the various penguin amplitudes using experimental data. The present B{yields}{pi}{pi} data suggest that there are large corrections to the heavy quark limit, which can be due to power corrections to the tree amplitudes, large up-penguin amplitude, or enhanced weak annihilation. Because the penguin contributions are smaller, the heavy quark limit is more consistent with the B{yields}{rho}{rho} data, and its implications may become important for the extraction of {alpha} from this mode in the future.

  16. Conserved roles for yeast Rho1 and mammalian RhoA GTPases in clathrin-independent endocytosis

    PubMed Central

    Prosser, Derek C.; Wendland, Beverly

    2012-01-01

    Eukaryotic cells use numerous endocytic pathways for nutrient uptake, protein turnover and response to the extracellular environment. While clathrin-mediated endocytosis (CME) has been extensively studied in yeast and mammalian cells, recent studies in higher eukaryotes have described multiple clathrin-independent endocytic pathways that depend upon Rho family GTPases and their effector proteins. In contrast, yeast cells have been thought to rely solely on CME. In a recent study, we used CME-defective yeast cells lacking clathrin-binding endocytic adaptor proteins in a genetic screen to identify novel factors involved in endocytosis. This approach revealed the existence of a clathrin-independent endocytic pathway involving the GTPase Rho1, which is the yeast homolog of RhoA. Further characterization of the yeast Rho1-mediated endocytic pathway suggested that the Rho1 pathway requires additional proteins that appear to play conserved roles in RhoA-dependent, clathrin-independent endocytic pathways in mammalian cells. Here, we discuss the parallels between the yeast Rho1-dependent and mammalian RhoA-dependent endocytic pathways, as well as the applications of yeast as a model for studying clathrin-independent endocytosis in higher eukaryotes. PMID:23238351

  17. The RhoGAP activity of CYK-4/MgcRacGAP functions non-canonically by promoting RhoA activation during cytokinesis

    PubMed Central

    Zhang, Donglei; Glotzer, Michael

    2015-01-01

    Cytokinesis requires activation of the GTPase RhoA. ECT-2, the exchange factor responsible for RhoA activation, is regulated to ensure spatiotemporal control of contractile ring assembly. Centralspindlin, composed of the Rho family GTPase-activating protein (RhoGAP) MgcRacGAP/CYK-4 and the kinesin MKLP1/ZEN-4, is known to activate ECT-2, but the underlying mechanism is not understood. We report that ECT-2-mediated RhoA activation depends on the ability of CYK-4 to localize to the plasma membrane, bind RhoA, and promote GTP hydrolysis by RhoA. Defects resulting from loss of CYK-4 RhoGAP activity can be rescued by activating mutations in ECT-2 or depletion of RGA-3/4, which functions as a conventional RhoGAP for RhoA. Consistent with CYK-4 RhoGAP activity contributing to GEF activation, the catalytic domains of CYK-4 and ECT-2 directly interact. Thus, counterintuitively, CYK-4 RhoGAP activity promotes RhoA activation. We propose that the most active form of the cytokinetic RhoGEF involves complex formation between ECT-2, centralspindlin and RhoA. DOI: http://dx.doi.org/10.7554/eLife.08898.001 PMID:26252513

  18. Rho resonance parameters from lattice QCD

    NASA Astrophysics Data System (ADS)

    Guo, Dehua; Alexandru, Andrei; Molina, Raquel; Döring, Michael

    2016-08-01

    We perform a high-precision calculation of the phase shifts for π -π scattering in the I =1 , J =1 channel in the elastic region using elongated lattices with two mass-degenerate quark flavors (Nf=2 ). We extract the ρ resonance parameters using a Breit-Wigner fit at two different quark masses, corresponding to mπ=226 MeV and mπ=315 MeV , and perform an extrapolation to the physical point. The extrapolation is based on a unitarized chiral perturbation theory model that describes well the phase shifts around the resonance for both quark masses. We find that the extrapolated value, mρ=720 (1 )(15 ) MeV , is significantly lower that the physical rho mass and we argue that this shift could be due to the absence of the strange quark in our calculation.

  19. Rho GTPase–independent regulation of mitotic progression by the RhoGEF Net1

    PubMed Central

    Menon, Sarita; Oh, Wonkyung; Carr, Heather S.; Frost, Jeffrey A.

    2013-01-01

    Neuroepithelial transforming gene 1 (Net1) is a RhoA-subfamily–specific guanine nucleotide exchange factor that is overexpressed in multiple human cancers and is required for proliferation. Molecular mechanisms underlying its role in cell proliferation are unknown. Here we show that overexpression or knockdown of Net1 causes mitotic defects. Net1 is required for chromosome congression during metaphase and generation of stable kinetochore microtubule attachments. Accordingly, inhibition of Net1 expression results in spindle assembly checkpoint activation. The ability of Net1 to control mitosis is independent of RhoA or RhoB activation, as knockdown of either GTPase does not phenocopy effects of Net1 knockdown on nuclear morphology, and effects of Net1 knockdown are effectively rescued by expression of catalytically inactive Net1. We also observe that Net1 expression is required for centrosomal activation of p21-activated kinase and its downstream kinase Aurora A, which are critical regulators of centrosome maturation and spindle assembly. These results identify Net1 as a novel regulator of mitosis and indicate that altered expression of Net1, as occurs in human cancers, may adversely affect genomic stability. PMID:23864709

  20. Rho GTPase Transcriptome Analysis Reveals Oncogenic Roles for Rho GTPase-Activating Proteins in Basal-like Breast Cancers.

    PubMed

    Lawson, Campbell D; Fan, Cheng; Mitin, Natalia; Baker, Nicole M; George, Samuel D; Graham, David M; Perou, Charles M; Burridge, Keith; Der, Channing J; Rossman, Kent L

    2016-07-01

    The basal-like breast cancer (BLBC) subtype accounts for a disproportionately high percentage of overall breast cancer mortality. The current therapeutic options for BLBC need improvement; hence, elucidating signaling pathways that drive BLBC growth may identify novel targets for the development of effective therapies. Rho GTPases have previously been implicated in promoting tumor cell proliferation and metastasis. These proteins are inactivated by Rho-selective GTPase-activating proteins (RhoGAP), which have generally been presumed to act as tumor suppressors. Surprisingly, RNA-Seq analysis of the Rho GTPase signaling transcriptome revealed high expression of several RhoGAP genes in BLBC tumors, raising the possibility that these genes may be oncogenic. To evaluate this, we examined the roles of two of these RhoGAPs, ArhGAP11A (also known as MP-GAP) and RacGAP1 (also known as MgcRacGAP), in promoting BLBC. Both proteins were highly expressed in human BLBC cell lines, and knockdown of either gene resulted in significant defects in the proliferation of these cells. Knockdown of ArhGAP11A caused CDKN1B/p27-mediated arrest in the G1 phase of the cell cycle, whereas depletion of RacGAP1 inhibited growth through the combined effects of cytokinesis failure, CDKN1A/p21-mediated RB1 inhibition, and the onset of senescence. Random migration was suppressed or enhanced by the knockdown of ArhGAP11A or RacGAP1, respectively. Cell spreading and levels of GTP-bound RhoA were increased upon depletion of either RhoGAP. We have established that, via the suppression of RhoA, ArhGAP11A and RacGAP1 are both critical drivers of BLBC growth, and propose that RhoGAPs can act as oncogenes in cancer. Cancer Res; 76(13); 3826-37. ©2016 AACR. PMID:27216196

  1. The Rho-GEF Gef3 interacts with the septin complex and activates the GTPase Rho4 during fission yeast cytokinesis

    PubMed Central

    Wang, Ning; Wang, Mo; Zhu, Yi-Hua; Grosel, Timothy W.; Sun, Daokun; Kudryashov, Dmitri S.; Wu, Jian-Qiu

    2015-01-01

    Rho GTPases, activated by Rho guanine nucleotide exchange factors (GEFs), are conserved molecular switches for signal transductions that regulate diverse cellular processes, including cell polarization and cytokinesis. The fission yeast Schizosaccharomyces pombe has six Rho GTPases (Cdc42 and Rho1–Rho5) and seven Rho GEFs (Scd1, Rgf1–Rgf3, and Gef1–Gef3). The GEFs for Rho2–Rho5 have not been unequivocally assigned. In particular, Gef3, the smallest Rho GEF, was barely studied. Here we show that Gef3 colocalizes with septins at the cell equator. Gef3 physically interacts with septins and anillin Mid2 and depends on them to localize. Gef3 coprecipitates with GDP-bound Rho4 in vitro and accelerates nucleotide exchange of Rho4, suggesting that Gef3 is a GEF for Rho4. Consistently, Gef3 and Rho4 are in the same genetic pathways to regulate septum formation and/or cell separation. In gef3∆ cells, the localizations of two potential Rho4 effectors—glucanases Eng1 and Agn1—are abnormal, and active Rho4 level is reduced, indicating that Gef3 is involved in Rho4 activation in vivo. Moreover, overexpression of active Rho4 or Eng1 rescues the septation defects of mutants containing gef3∆. Together our data support that Gef3 interacts with the septin complex and activates Rho4 GTPase as a Rho GEF for septation in fission yeast. PMID:25411334

  2. Inhibition of Rho A activity causes pemphigus skin blistering

    PubMed Central

    Waschke, Jens; Spindler, Volker; Bruggeman, Paola; Zillikens, Detlef; Schmidt, Gudula; Drenckhahn, Detlev

    2006-01-01

    The autoimmune blistering skin diseases pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are mainly caused by autoantibodies against desmosomal cadherins. In this study, we provide evidence that PV–immunoglobulin G (IgG) and PF-IgG induce skin blistering by interference with Rho A signaling. In vitro, pemphigus IgG caused typical hallmarks of pemphigus pathogenesis such as epidermal blistering in human skin, cell dissociation, and loss of desmoglein 1 (Dsg 1)–mediated binding probed by laser tweezers. These changes were accompanied by interference with Rho A activation and reduction of Rho A activity. Pemphigus IgG–triggered keratinocyte dissociation and Rho A inactivation were p38 mitogen-activated protein kinase dependent. Specific activation of Rho A by cytotoxic necrotizing factor-y abolished all pemphigus-triggered effects, including keratin retraction and release of Dsg 3 from the cytoskeleton. These data demonstrate that Rho A is involved in the regulation of desmosomal adhesion, at least in part by maintaining the cytoskeletal anchorage of desmosomal proteins. This may open the possibility of pemphigus treatment with the epidermal application of Rho A agonists. PMID:17130286

  3. Novel peptide recognized by RhoA GTPase.

    PubMed

    Drulis-Fajdasz, Dominika; Jelen, Filip; Oleksy, Arkadiusz; Otlewski, Jacek

    2006-01-01

    A phage-displayed random 7-mer disulfide bridge-constrained peptide library was used to map the surface of the RhoA GTPase and to find peptides able to recognize RhoA switch regions. Several peptide sequences were selected after four rounds of enrichment, giving a high signal in ELISA against RhoA-GDP. A detailed analysis of one such selected peptide, called R2 (CWSFPGYAC), is reported. The RhoA-R2 interaction was investigated using fluorescence spectroscopy, chemical denaturation, and determination of the kinetics of nucleotide exchange and GTP hydrolysis in the presence of RhoA regulatory proteins. All measurements indicate that the affinity of the R2 peptide for RhoA is in the micromolar range and that R2 behaves as an inhibitor of: i) GDP binding to the apo form of RhoA (Mg2+-and nucleotide-free form of the GTPase), ii) nucleotide exchange stimulated by GEF (DH/PH tandem from PDZRhoGEF), and iii) GTP hydrolysis stimulated by the BH domain of GrafGAP protein. PMID:17019437

  4. Scambio, a novel guanine nucleotide exchange factor for Rho

    PubMed Central

    Curtis, Christina; Hemmeryckx, Bianca; Haataja, Leena; Senadheera, Dinithi; Groffen, John; Heisterkamp, Nora

    2004-01-01

    Background Small GTPases of the Rho family are critical regulators of various cellular functions including actin cytoskeleton organization, activation of kinase cascades and mitogenesis. For this reason, a major objective has been to understand the mechanisms of Rho GTPase regulation. Here, we examine the function of a novel protein, Scambio, which shares homology with the DH-PH domains of several known guanine nucleotide exchange factors for Rho family members. Results Scambio is located on human chromosome 14q11.1, encodes a protein of around 181 kDa, and is highly expressed in both heart and skeletal muscle. In contrast to most DH-PH-domain containing proteins, it binds the activated, GTP-bound forms of Rac and Cdc42. However, it fails to associate with V14RhoA. Immunofluorescence studies indicate that Scambio and activated Rac3 colocalize in membrane ruffles at the cell periphery. In accordance with these findings, Scambio does not activate either Rac or Cdc42 but rather, stimulates guanine nucleotide exchange on RhoA and its close relative, RhoC. Conclusion Scambio associates with Rac in its activated conformation and functions as a guanine nucleotide exchange factor for Rho. PMID:15107133

  5. Tension on JAM-A activates RhoA via GEF-H1 and p115 RhoGEF

    PubMed Central

    Scott, David W.; Tolbert, Caitlin E.; Burridge, Keith

    2016-01-01

    Junctional adhesion molecule A (JAM-A) is a broadly expressed adhesion molecule that regulates cell–cell contacts and facilitates leukocyte transendothelial migration. The latter occurs through interactions with the integrin LFA-1. Although we understand much about JAM-A, little is known regarding the protein’s role in mechanotransduction or as a modulator of RhoA signaling. We found that tension imposed on JAM-A activates RhoA, which leads to increased cell stiffness. Activation of RhoA in this system depends on PI3K-mediated activation of GEF-H1 and p115 RhoGEF. These two GEFs are further regulated by FAK/ERK and Src family kinases, respectively. Finally, we show that phosphorylation of JAM-A at Ser-284 is required for RhoA activation in response to tension. These data demonstrate a direct role of JAM-A in mechanosignaling and control of RhoA and implicate Src family kinases in the regulation of p115 RhoGEF. PMID:26985018

  6. Measurement of branching fractions and charge asymmetries in B+/--->rho+/-pi0 and B+/--->rho0pi+/- decays, and search for B0-->rho0pi0.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; LeClerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Romosan, A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Knowles, D J; Morgan, S E; Penny, R C; Watson, A T; Watson, N K; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmuecker, H; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Mackay, C; Wilson, F F; Abe, K; Cuhadar-Donszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Teodorescu, L; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Gary, J W; Layter, J; Shen, B C; Wang, K; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Spradlin, P; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Erwin, R J; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Dubitzky, R S; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Wilden, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Grenier, P; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Khan, A; Lavin, D; Muheim, F; Playfer, S; Swain, J E; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Falciai, D; Finocchiaro, G; Patteri, P; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Won, E; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Gaillard, J R; Morton, G W; Nash, J A; Taylor, G P; Grenier, G J; Lee, S-J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Brigljević, V; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Kay, M; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Shorthouse, H W; Vidal, P B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Jackson, F; Lafferty, G D; Lyon, A J; Weatherall, J H; Williams, J C; Farbin, A; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Cote-Ahern, D; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; LoSecco, J M; Gabriel, T A; Brau, B; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; Stark, J; T'Jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Anulli, F; Biasini, M; Peruzzi, I M; Pioppi, M; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Del Gamba, V; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Tanaka, H A; Varnes, E W; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yeche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Cristinziani, M; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Field, R C; Glanzman, T; Gowdy, S J; Grauges-Pous, E; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocian, M L; Langenegger, U; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, M; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2004-07-30

    We present measurements of branching fractions and charge asymmetries in B-meson decays to rho(+)pi(0), rho(0)pi(+), and rho(0)pi(0). The data sample comprises 89x10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We find the charge-averaged branching fractions B(B+-->rho(+)pi(0))=[10.9+/-1.9(stat)+/-1.9(syst)]x10(-6) and B(B+-->rho(0)pi(+))=(9.5+/-1.1+/-0.9)x10(-6), and we set a 90% confidence-level upper limit B(B0-->rho(0)pi(0))<2.9x10(-6). We measure the charge asymmetries ACP(pi(0))(rho(+))=0.24+/-0.16+/-0.06 and ACP(pi(+))(rho(0))=-0.19+/-0.11+/-0.02. PMID:15323685

  7. Search for medium modification of the $\\rho$ meson

    SciTech Connect

    R. Nasseripour; M. H. Wood; C. Djalali; D. P. Weygand; C. Tur; U. Mosel; P. Muehlich; CLAS Collaboration

    2007-08-01

    The photoproduction of vector mesons on various nuclei has been studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory. The vector mesons, $\\rho$, $\\omega$, and $\\phi$, are observed via their decay to $e^+e^-$, in order to reduce the effects of final state interactions in the nucleus. Of particular interest are possible in-medium effects on the properties of the $\\rho$ meson. The $\\rho$ spectral function is extracted from the data on various nuclei, carbon, iron, and titanium, and compared to the spectrum from liquid deuterium, which is relatively free of nuclear effects. We observe no significant mass shift for the $\\rho$ meson; however, there is some widening of the resonance in titanium and iron, which is consistent with expected collisional broadening.

  8. Safety profile of WinRho anti-D.

    PubMed

    Hong, F; Ruiz, R; Price, H; Griffiths, A; Malinoski, F; Woloski, M

    1998-01-01

    WinRho anti-D is manufactured with multiple processes to minimize the risk of transmitting blood-borne diseases such as viruses. These safety features include donor selection, plasma testing, solvent-detergent viral inactivation, and nanofiltration. To date, there has not been any case of viral transmission in association with use of WinRho anti-D. Adverse drug reactions are infrequent and generally mild; the most common are headache, fever, and chills. Some degree of hemolysis is inevitable due to the mechanism of action of WinRho anti-D, but this is predictable and transient. A few cases of intravascular hemolysis have been reported; hypersensitivity reactions are very rare. WinRho anti-D has been shown in both clinical trials and postmarketing surveillance to be safe and effective in the treatment of idiopathic thrombocytopenic purpura (ITP) and in the prevention of Rh isoimmunization. PMID:9523744

  9. Techni-rho production at SSC and LHC

    SciTech Connect

    Bagger, J. . Dept. of Physics and Astronomy); Han, T. ); Rosenfeld, R. . Dept. of Physics)

    1990-01-01

    We use a parton-level Monte Carlo to assess the reach of the SSC and LHC for discovering a techni-rho through its purely leptonic decay channels. We find the techni-rho couplings using the familiar techniques of nonlinear realizations. We compute the signal and background for techni-rhos of arbitrary mass and width, restricted only by requirements of partial-wave unitarity. 24 refs., 5 figs., 3 tabs.

  10. Constraining |V(td)|/|V(ts)| Using Radiative Penguin B -> V(K*/rho/omega)gamma Decays

    SciTech Connect

    Tan, Ping; /Wisconsin U., Madison

    2006-03-08

    Exclusive radiative penguin B decays, B {yields} (K*{sup 0}/K*{sup +}) and B {yields} ({rho}/{omega}){gamma}, are flavor-changing neutral-current (FCNC) processes. Studies of these decays are of special interest in testing Standard Model (SM) predictions and searching for other beyond-the-SM FCNC interactions. Using 89 x 10{sup 6} B{bar B} pairs from BABAR, we measure the branching fraction ({Beta}), CP-asymmetry ({Alpha}), and isospin asymmetry ({Delta}{sub 0-}) of B {yields} (K*{sup 0}/K*{sup +}){gamma} as follows: {Beta}(B{sup 0} {yields} K*{sup 0}{gamma}) = 3.92 {+-} 0.20(stat.) {+-} 0.24(syst.); {Beta}(B{sup +} {yields} K*{sup +}{gamma}) = 3.87 {+-} 0.28(stat.) {+-} 0.26(syst.); {Alpha}(B {yields} K*{gamma}) = -0.013 {+-} 0.36(stat.) {+-} 0.10(syst.); {Delta}{sub 0-}(B {yields} K*{gamma}) = 0.050 {+-} 0.045(stat.) {+-} 0.028(syst.) {+-} 0.024(R{sup +/0}). The 90% confidence intervals for the CP-asymmetry and the isospin-asymmetry in the B {yields} K*{gamma} decay are given as: -0.074 < {Alpha}(B {yields} K*{gamma}) < 0.049, -0.046 < {Delta}{sub 0-} (B {yields} K*{gamma}) < 0.146. We also search for B {yields} ({rho}/{omega}){gamma} decays using 211 x 10{sup 6} B{bar B} pairs from BABAR. No evidence for these decays is found. We set the upper limits at 90% confidence level for these decays: {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) < 0.4 x 10{sup -6}; {Beta}(B{sup +}{yields} {rho}{sup =}{gamma}) < 1.8 x 10{sup -6}; {Beta}(B{sup 0} {yields} {omega}{gamma}) < 1.0 x 10{sup -6}; {bar {Beta}}(B {yields} ({rho}/{omega}){gamma}) < 1.2 x 10{sup -6}. These results are in good agreement with the SM predictions. The branching fractions of these decays are then used to constrain the ratio |V{sub td}|/|V{sub ts}|.

  11. Regulation of Neurotrophin-Induced Axonal Responses via Rho GTPases

    PubMed Central

    HANDEÖZDINLER, P.; ERZURUMLU, REHA S.

    2014-01-01

    Nerve growth factor (NGF) and related neurotrophins induce differential axon growth patterns from embryonic sensory neurons. In wholemount explant cultures of embryonic rat trigeminal ganglion and brainstem or in dissociated cell cultures of the trigeminal ganglion, exogenous supply of NGF leads to axonal elongation, whereas neurotrophin-3 (NT-3) treatment leads to short branching and arborization. Axonal responses to neurotrophins might be mediated via the Rho GTPases. To investigate this possibility, we prepared wholemount trigeminal pathway cultures from E15 rats. We infected the ganglia with recombinant vaccinia viruses that express GFP-tagged dominant negative Rac, Rho, or constitutively active Rac or treated the cultures with lysophosphatitic acid (LPA) to activate Rho. We then examined axonal responses to NGF by use of the lipophilic tracer DiI. Rac activity induced longer axonal growth from the central trigeminal tract, whereas the dominant negative construct of Rac eliminated NGF-induced axon outgrowth. Rho activity also significantly reduced, and the Rho dominant negative construct increased, axon growth from the trigeminal tract. Similar alterations in axonal responses to NT-3 and brain-derived neurotrophic factor were also noted. Our results demonstrate that Rho GTPases play a major role in neurotrophin-induced axonal differentiation of embryonic trigeminal axons. PMID:11559894

  12. Control of T lymphocyte morphology by the GTPase Rho

    NASA Technical Reports Server (NTRS)

    Woodside, Darren G.; Wooten, David K.; Teague, T. Kent; Miyamoto, Yuko J.; Caudell, Eva G.; Udagawa, Taturo; Andruss, Bernard F.; McIntyre, Bradley W.

    2003-01-01

    BACKGROUND: Rho family GTPase regulation of the actin cytoskeleton governs a variety of cell responses. In this report, we have analyzed the role of the GTPase Rho in maintenance of the T lymphocyte actin cytoskeleton. RESULTS: Inactivation of the GTPase Rho in the human T lymphocytic cell line HPB-ALL does not inhibit constitutively high adhesion to the integrin beta1 substrate fibronectin. It did however result in the aberrant extension of finger-like dendritic processes on the substrates VCAM-1, Fn, and mAb specific to beta1 integrins. Time-lapse video microscopy demonstrated that C3 induced extensions were primarily the result of an altered pseudopod elongation rather than retraction. Once the stellate pseudopodia extended, none retracted, and cells became completely immobile. Filipodial structures were absent and the dendritic-like processes in C3 treated cells were rich in filamentous actin. Immunolocalization of RhoA in untreated HPB-ALL cells spreading on fibronectin demonstrated a diffuse staining pattern within the pseudopodia. In C3 treated cells, clusters of RhoA were pronounced and localized within the altered extensions. CONCLUSIONS: GTPase Rho is actively involved in the regulation of T lymphocyte morphology and motility.

  13. Rho-Kinase–Mediated Contraction of Isolated Stress Fibers

    PubMed Central

    Katoh, Kazuo; Kano, Yumiko; Amano, Mutsuki; Onishi, Hirofumi; Kaibuchi, Kozo; Fujiwara, Keigi

    2001-01-01

    It is widely accepted that actin filaments and the conventional double-headed myosin interact to generate force for many types of nonmuscle cell motility, and that this interaction occurs when the myosin regulatory light chain (MLC) is phosphorylated by MLC kinase (MLCK) together with calmodulin and Ca2+. However, recent studies indicate that Rho-kinase is also involved in regulating the smooth muscle and nonmuscle cell contractility. We have recently isolated reactivatable stress fibers from cultured cells and established them as a model system for actomyosin-based contraction in nonmuscle cells. Here, using isolated stress fibers, we show that Rho-kinase mediates MLC phosphorylation and their contraction in the absence of Ca2+. More rapid and extensive stress fiber contraction was induced by MLCK than was by Rho-kinase. When the activity of Rho-kinase but not MLCK was inhibited, cells not only lost their stress fibers and focal adhesions but also appeared to lose cytoplasmic tension. Our study suggests that actomyosin-based nonmuscle contractility is regulated by two kinase systems: the Ca2+-dependent MLCK and the Rho-kinase systems. We propose that Ca2+ is used to generate rapid contraction, whereas Rho-kinase plays a major role in maintaining sustained contraction in cells. PMID:11331307

  14. Search for radiative penguin decays B(+)-->rho(+)gamma, B(0)-->rho(0)gamma, and B(0)-->omegagamma.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Couderc, F; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Shelkov, V G; Wenzel, W A; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Fritsch, M; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Steinke, M; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Wilson, F F; Cuhadar-Donszelmann, T; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Thiessen, D; Khan, A; Kyberd, P; Teodorescu, L; Blinov, A E; Blinov, V E; Druzhinin, V P; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Bruinsma, M; Chao, M; Eschrich, I; Kirkby, D; Lankford, A J; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; Hartfiel, B L; Foulkes, S D; Gary, J W; Shen, B C; Wang, K; Del Re, D; Hadavand, H K; Hill, E J; Macfarlane, D B; Paar, H P; Rahatlou, Sh; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Eisner, A M; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Blanc, F; Bloom, P; Chen, S; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Smith, J G; Zhang, J; Zhang, L; Chen, A; Harton, J L; Soffer, A; Toki, W H; Wilson, R J; Zeng, Q L; Altenburg, D; Brandt, T; Brose, J; Dickopp, M; Feltresi, E; Hauke, A; Lacker, H M; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Petzold, A; Schubert, J; Schubert, K R; Schwierz, R; Spaan, B; Sundermann, J E; Bernard, D; Bonneaud, G R; Brochard, F; Grenier, P; Schrenk, S; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Bard, D J; Clark, P J; Lavin, D; Muheim, F; Playfer, S; Xie, Y; Andreotti, M; Azzolini, V; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Crosetti, G; Vetere, M Lo; Macri, M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Won, E; Dubitzky, R S; Langenegger, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Gaillard, J R; Morton, G W; Nash, J A; Nikolich, M B; Taylor, G P; Charles, M J; Grenier, G J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Yi, J; Biasini, M; Covarelli, R; Pioppi, M; Davier, M; Giroux, X; Grosdidier, G; Höcker, A; Laplace, S; Diberder, F Le; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Cheng, C H; Lange, D J; Simani, M C; Wright, D M; Bevan, A J; Chavez, C A; Coleman, J P; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Cormack, C M; Harrison, P F; Lodovico, F Di; Mohanty, G B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; Green, M G; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Hart, P A; Hodgkinson, M C; Lafferty, G D; Lyon, A J; Williams, J C; Farbin, A; Hulsbergen, W D; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Sekula, S J; Taylor, F; Yamamoto, R K; Mangeol, D J J; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Nicholson, H; Cavallo, N; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Bulten, H; Raven, G; Snoek, H L; Wilden, L; Jessop, C P; Losecco, J M; Allmendinger, T; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Pulliam, T; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Brau, J; Frey, R; Igonkina, O; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Buono, L Del; Hamon, O; John, M J J; Leruste, Ph; Malcles, J; Ocariz, J; Pivk, M; Roos, L; T'jampens, S; Therin, G; Manfredi, P F; Re, V; Behera, P K; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Gioi, L Li; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Tehrani, F Safai; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; Groot, N De; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; de Monchenault, G Hamel; Kozanecki, W; Legendre, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yèche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Wilson, J R; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; Nardo, G De; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Elsen, E E; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Leith, D W G S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Petersen, B A; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saeed, M A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Satpathy, A; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Bosisio, L; Cartaro, C; Cossutti, F; Ricca, G Della; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Sobie, R J; Band, H R; Cheng, B; Dasu, S; Datta, M; Eichenbaum, A M; Graham, M; Hollar, J J; Johnson, J R; Kutter, P E; Li, H; Liu, R; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Tan, P; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Greene, M G; Neal, H

    2005-01-14

    A search for the decays B-->rho(770)gamma and B0-->omega(782)gamma is performed on a sample of 211 x 10(6) Upsilon(4S)-->BB events collected by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring. No evidence for the decays is seen. We set the following limits on the individual branching fractions: B(B+-->rho(+)gamma)<1.8 x 10(-6), B(B0-->rho(0)gamma)<0.4 x 10(-6), and B(B0-->omegagamma)<1.0 x 10(-6) at the 90% confidence level. We use the quark model to limit the combined branching fraction B [B-->(rho/omega)gamma]<1.2 x 10(-6), from which we determine a constraint on the ratio of Cabibbo-Kobayashi-Maskawa matrix elements |V(td)|/|V(ts)|. PMID:15698065

  15. AAMP Regulates Endothelial Cell Migration and Angiogenesis Through RhoA/Rho Kinase Signaling.

    PubMed

    Hu, Jianjun; Qiu, Juhui; Zheng, Yiming; Zhang, Tao; Yin, Tieying; Xie, Xiang; Wang, Guixue

    2016-05-01

    Angiogenesis is a complicated process including endothelial cell proliferation, migration and tube formation. AAMP plays a role in regulating cell migration of multiple cell types. The purpose of this study was to investigate whether AAMP regulates angiogenesis, and to clarify the role of AAMP in the VEGF-induced angiogenesis. We found that AAMP expressed in multiple cell types and mainly localized in cytoplasm and membrane in vascular endothelial cells. Using tube formation assay in vitro and aortic ring assay, siRNA-mediated knockdown and antibody blockade of AAMP impaired VEGF-induced endothelial cell tube formation and aortic ring angiogenic sprouting. Mechanistic studies showed that AAMP expression was significantly upregulated by VEGF in a concentration and time-dependent manner. Moreover, VEGF recruited AAMP to the cell membrane protrusions. AAMP regulates angiogenesis by mediating the spreading and migration of vascular endothelial cells. AAMP knock-down reduced VEGF-induced actin stress fibers and collagen gel contraction. Furthermore, we identified RhoA/Rho kinase signaling as an important factor that contributes to the action of AAMP in regulating endothelial cell migration and angiogenesis. Altogether, these data demonstrated the critical role of AAMP in angiogenesis and suggested blocking AAMP could serve as a potential therapeutic strategy for angiogenesis-related diseases. PMID:26350504

  16. Diabetes Causes Bone Marrow Endothelial Barrier Dysfunction by Activation of the RhoA–Rho-Associated Kinase Signaling Pathway

    PubMed Central

    Mangialardi, Giuseppe; Katare, Rajesh; Oikawa, Atsuhiko; Meloni, Marco; Reni, Carlotta; Emanueli, Costanza; Madeddu, Paolo

    2013-01-01

    Objective Diabetes mellitus causes bone marrow (BM) microangiopathy. This study aimed to investigate the mechanisms responsible for BM endothelial dysfunction in diabetes mellitus. Methods and Results The analysis of differentially expressed transcripts in BM endothelial cells (BMECs) from type-1 diabetic and nondiabetic mice showed an effect of diabetes mellitus on signaling pathways controlling cell death, migration, and cytoskeletal rearrangement. Type-1 diabetic-BMECs displayed high reactive oxygen species levels, increased expression and activity of RhoA and its associated protein kinases Rho-associated kinase 1/Rho-associated kinase 2, and reduced Akt phosphorylation/activity. Likewise, diabetes mellitus impaired Akt-related BMEC functions, such as migration, network formation, and angiocrine factor-releasing activity, and increased vascular permeability. Moreover, high glucose disrupted BMEC contacts through Src tyrosine kinase phosphorylation of vascular endothelial cadherin. These alterations were prevented by constitutively active Akt (myristoylated Akt), Rho-associated kinase inhibitor Y-27632, and Src inhibitors. Insulin replacement restored BMEC abundance, as assessed by flow cytometry analysis of the endothelial marker MECA32, and endothelial barrier function in BM of type-1 diabetic mice. Conclusion Redox-dependent activation of RhoA/Rho-associated kinase and Src/vascular endothelial cadherin signaling pathways, together with Akt inactivation, contribute to endothelial dysfunction in diabetic BM. Metabolic control is crucial for maintenance of endothelial cell homeostasis and endothelial barrier function in BM of diabetic mice. PMID:23307872

  17. Measurements of Branching Fractions for B+ -> rho+ gamma, B0 -> rho0 gamma, and B0 -> omega gamma

    SciTech Connect

    Aubert, B

    2008-08-15

    The authors present branching fraction measurements for the radiative decays B{sup +} {yields} {rho}{sup +}{gamma}, B{sup 0} {yields} {rho}{sup 0}{gamma}, and B{sup 0} {yields} {omega}{gamma}. The analysis is based on a data sample of 465 million B{bar B} events collected with the BABAR detector at the PEP-II asymmetric-energy B Factory located at the Stanford Linear Accelerator Center (SLAC). They find {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.20{sub -0.37}{sup +0.42} {+-} 0.20) x 10{sup -6}, {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.97{sub -0.22}{sup +0.24} {+-} 0.06) x 10{sup -6}, and a 90% C.L. upper limit {Beta}(B{sup 0} {yields} {omega}{gamma}) < 0.9 x 10{sup -6}, where the first error is statistical and the second is systematic. They also measure the isospin-violating quantity {Lambda}(B{sup +} {yields} {rho}{sup +}{gamma})/2{Lambda}(B{sup 0} {yields} {rho}{sup 0}{gamma}) - 1 = -0.43{sub -0.22}{sup +0.25} {+-} 0.10.

  18. A conserved RhoGAP limits M phase contractility and coordinates with microtubule asters to confine RhoA during cytokinesis.

    PubMed

    Zanin, Esther; Desai, Arshad; Poser, Ina; Toyoda, Yusuke; Andree, Cordula; Moebius, Claudia; Bickle, Marc; Conradt, Barbara; Piekny, Alisa; Oegema, Karen

    2013-09-16

    During animal cell cytokinesis, the spindle directs contractile ring assembly by activating RhoA in a narrow equatorial zone. Rapid GTPase activating protein (GAP)-mediated inactivation (RhoA flux) is proposed to limit RhoA zone dimensions. Testing the significance of RhoA flux has been hampered by the fact that the GAP targeting RhoA is not known. Here, we identify M phase GAP (MP-GAP) as the primary GAP targeting RhoA during mitosis and cytokinesis. MP-GAP inhibition caused excessive RhoA activation in M phase, leading to the uncontrolled formation of large cortical protrusions and late cytokinesis failure. RhoA zone width was broadened by attenuation of the centrosomal asters but was not affected by MP-GAP inhibition alone. Simultaneous aster attenuation and MP-GAP inhibition led to RhoA accumulation around the entire cell periphery. These results identify the major GAP restraining RhoA during cell division and delineate the relative contributions of RhoA flux and centrosomal asters in controlling RhoA zone dimensions. PMID:24012485

  19. Activated RhoA Binds to the Pleckstrin Homology (PH) Domain of PDZ-RhoGEF, a Potential Site for Autoregulation

    SciTech Connect

    Chen, Zhe; Medina, Frank; Liu, Mu-ya; Thomas, Celestine; Sprang, Stephen R.; Sternweis, Paul C.

    2010-07-19

    Guanine nucleotide exchange factors (GEFs) catalyze exchange of GDP for GTP by stabilizing the nucleotide-free state of the small GTPases through their Dbl homology/pleckstrin homology (DH {center_dot} PH) domains. Unconventionally, PDZ-RhoGEF (PRG), a member of the RGS-RhoGEFs, binds tightly to both nucleotide-free and activated RhoA (RhoA {center_dot} GTP). We have characterized the interaction between PRG and activated RhoA and determined the structure of the PRG-DH {center_dot} PH-RhoA {center_dot} GTP{gamma}S (guanosine 5{prime}-O-[{gamma}-thio]triphosphate) complex. The interface bears striking similarity to a GTPase-effector interface and involves the switch regions in RhoA and a hydrophobic patch in PRG-PH that is conserved among all Lbc RhoGEFs. The two surfaces that bind activated and nucleotide-free RhoA on PRG-DH {center_dot} PH do not overlap, and a ternary complex of PRG-DH {center_dot} PH bound to both forms of RhoA can be isolated by size-exclusion chromatography. This novel interaction between activated RhoA and PH could play a key role in regulation of RhoGEF activity in vivo.

  20. The GNA13-RhoA signaling axis suppresses expression of tumor protective Kallikreins.

    PubMed

    Teo, Cui Rong; Casey, Patrick J; Rasheed, Suhail Ahmed Kabeer

    2016-10-01

    Gα13 (encoded by GNA13 gene) is the alpha subunit of a heterotrimeric G-protein that mediates signaling through specific G-protein-coupled receptors (GPCRs). Increased GNA13 expression has been observed in metastatic breast cancer cells. Recently, we have shown that enhanced GNA13 signaling in MCF-10a cells, a benign breast cancer cell line increased its invasiveness. Previous studies have reported that Kallikrein-related peptidases (KLKs 1-15) are down-regulated in breast tumors and may have a tumor protective function. However, the mechanisms that lead to the down-regulation of KLK genes in breast cancer are yet to be elucidated. We found that enhanced GNA13 signaling represses KLK gene expression in breast cancer, and undertook examination of the mechanisms involved. A microarray analysis revealed down-regulation of several members of the Kallikrein-related peptidases (KLK) gene family, namely KLK5, KLK6, KLK7, KLK8 and KLK10, in MCF-10a lines with enhanced GNA13 protein expression. Using real-time PCR and promoter analysis, we identified that the mRNA expression and promoter activities of these KLKs are suppressed upon enforced expression of GNA13 in MCF-10a cells. Using Rhotekin pull-down assays, we identified that GNA13 suppressed Rho-A activation and protein levels in MCF-10a cells. Blocking Rho-A activation using C3-toxin or by inhibiting its down-stream effector, Rho-associated kinase (ROCK), reduced the above-mentioned KLK mRNAs in MCF-10A cells. Importantly, in a metastatic breast cancer cell line MDA-MB-157, knock down of GNA13 alone was sufficient to induce the expression KLK mRNAs. Taken together, our findings suggested that enhanced GNA13 signaling down-regulates KLK gene transcription. The ability of enhanced GNA13 signaling to suppress KLK gene expression appears at least in part due to the ability of enhanced GNA13 signaling to negatively impact Rho/ROCK-signaling. PMID:27424208

  1. Alpha Thalassemia

    MedlinePlus

    ... an apparently normal individual has a child with hemoglobin H disease or alpha thalassemia minor. It can ... gene on one chromosome 25% 25% 25% 25% hemoglobin H disease there is a 25% chance with ...

  2. TROY Interacts with Rho Guanine Nucleotide Dissociation Inhibitor α (RhoGDIα) to Mediate Nogo-induced Inhibition of Neurite Outgrowth*

    PubMed Central

    Lu, Yan; Liu, Xiujie; Zhou, Jianfeng; Huang, Aijun; Zhou, Jiazhen; He, Cheng

    2013-01-01

    TROY can functionally substitute p75 to comprise the Nogo receptor complex, which transduces the inhibitory signal of myelin-associated inhibitory factors on axon regeneration following CNS injury. The inhibition of neurite extension relies on TROY-dependent RhoA activation, but how TROY activates RhoA remains unclear. Here, we firstly identified Rho guanine nucleotide dissociation inhibitor α (RhoGDIα) as a binding partner of TROY using GST pull-down combined with two-dimensional gel electrophoresis and mass spectra analysis. The interaction was further confirmed by coimmunoprecipitation in vitro and in vivo. Deletion mutagenesis revealed that two regions of the TROY intracellular domain (amino acids 234–256 and 321–350) were essential for the interaction with RhoGDIα. Secondly, TROY and RhoGDIα were coexpressed in postnatal dorsal root ganglion neurons, cortex neurons, and cerebellar granule neurons (CGNs). Thirdly, TROY/RhoGDIα association was potentiated by Nogo-66 and was independent of p75/RhoGDIα interaction. Fourthly, TROY/RhoGDIα interaction was still able to activate RhoA when p75 was deficient. Furthermore, RhoA activation was decreased dramatically when TROY was knocked down in p75-deficient CGNs cells. Finally, RhoGDIα overexpression abolished RhoA activation and following neurite outgrowth inhibition by Nogo-66 in both wild-type and p75-deficient CGNs. These results showed that the association of RhoGDIα with TROY contributed to TROY-dependent RhoA activation and neurite outgrowth inhibition after Nogo-66 stimulation. PMID:24129566

  3. Systematic expression and loss-of-function analysis defines spatially restricted requirements for Drosophila RhoGEFs and RhoGAPs in leg morphogenesis

    PubMed Central

    Greenberg, Lina; Hatini, Victor

    2010-01-01

    The Drosophila leg imaginal disc consists of a peripheral region that contributes to adult body wall, and a central region that forms the leg proper. While the patterning signals and transcription factors that determine the identity of adult structures have been identified, the mechanisms that determine the shape of these structures remain largely unknown. The family of Rho GTPases, which consists of 7 members in flies, modulates cell adhesion, actomyosin contractility, protrusive membrane activity, and cell-matrix adhesion to generate mechanical forces that shape adult structures. The Rho GTPases are ubiquitously expressed and it remains unclear how they orchestrate morphogenetic events. The Rho guanine nucleotide exchange factors (RhoGEFs) and Rho GTPase activating proteins (RhoGAPs), which respectively activate and deactivate corresponding Rho GTPases, have been proposed to regulate the activity of Rho signaling cascades in specific spatiotemporal patterns to orchestrate morphogenetic events. Here we identify restricted expression of 12 of the 20 RhoGEFs and 10 of the 22 Rho RhoGAPs encoded in Drosophila during metamorphosis. Expression of a subset of each family of RhoGTPase regulators was restricted to motile cell populations including tendon, muscle, trachea, and peripodial stalk cells. A second subset was restricted either to all presumptive joints or only to presumptive tarsal joints. Depletion of individual RhoGEFs and RhoGAPs in the epithelium of the disc proper identified several joint-specific genes, which act downstream of segmental patterning signals to control epithelial morphogenesis. Our studies provide a framework with which to understand how Rho signaling cascades orchestrate complex morphogenetic events in multicellular organisms, and evidence that patterning signals regulate these cascades to control apical constriction and epithelial invagination at presumptive joints. PMID:20851182

  4. Made to measure – keeping Rho kinase at a distance

    PubMed Central

    Truebestein, Linda; Elsner, Daniel J.; Leonard, Thomas A.

    2016-01-01

    ABSTRACT The Rho-associated coiled-coil containing kinases (ROCK) were first identified as effectors of the small GTPase RhoA, hence their nomenclature. Since their discovery, two decades ago, scientists have sought to unravel the structure, regulation, and function of these essential kinases. During that time, a consensus model has formed, in which ROCK activity is regulated via both Rho-dependent and independent mechanisms. However, recent findings have raised significant questions regarding this model. In their recent publication in Nature Communications, Truebestein and colleagues present the structure of a full-length Rho kinase for the first time. In contrast to previous reports, the authors could find no evidence for autoinhibition, RhoA binding, or regulation of kinase activity by phosphorylation. Instead, they propose that ROCK functions as a molecular ruler, in which the central coiled-coil bridges the membrane-binding regulatory domains to the kinase domains at a fixed distance from the plasma membrane. Here, we explore the consequences of the new findings, re-examine old data in the context of this model, and emphasize outstanding questions in the field. PMID:27070834

  5. The interdependence of the Rho GTPases and apicobasal cell polarity

    PubMed Central

    Mack, Natalie Ann; Georgiou, Marios

    2014-01-01

    Signaling via the Rho GTPases provides crucial regulation of numerous cell polarization events, including apicobasal (AB) polarity, polarized cell migration, polarized cell division and neuronal polarity. Here we review the relationships between the Rho family GTPases and epithelial AB polarization events, focusing on the 3 best-characterized members: Rho, Rac and Cdc42. We discuss a multitude of processes that are important for AB polarization, including lumen formation, apical membrane specification, cell-cell junction assembly and maintenance, as well as tissue polarity. Our discussions aim to highlight the immensely complex regulatory mechanisms that encompass Rho GTPase signaling during AB polarization. More specifically, in this review we discuss several emerging common themes, that include: 1) the need for Rho GTPase activities to be carefully balanced in both a spatial and temporal manner through a multitude of mechanisms; 2) the existence of signaling feedback loops and crosstalk to create robust cellular responses; and 3) the frequent multifunctionality that exists among AB polarity regulators. Regarding this latter theme, we provide further discussion of the potential plasticity of the cell polarity machinery and as a result the possible implications for human disease. PMID:25469537

  6. The interdependence of the Rho GTPases and apicobasal cell polarity.

    PubMed

    Mack, Natalie Ann; Georgiou, Marios

    2014-01-01

    Signaling via the Rho GTPases provides crucial regulation of numerous cell polarization events, including apicobasal (AB) polarity, polarized cell migration, polarized cell division and neuronal polarity. Here we review the relationships between the Rho family GTPases and epithelial AB polarization events, focusing on the 3 best-characterized members: Rho, Rac and Cdc42. We discuss a multitude of processes that are important for AB polarization, including lumen formation, apical membrane specification, cell-cell junction assembly and maintenance, as well as tissue polarity. Our discussions aim to highlight the immensely complex regulatory mechanisms that encompass Rho GTPase signaling during AB polarization. More specifically, in this review we discuss several emerging common themes, that include: 1) the need for Rho GTPase activities to be carefully balanced in both a spatial and temporal manner through a multitude of mechanisms; 2) the existence of signaling feedback loops and crosstalk to create robust cellular responses; and 3) the frequent multifunctionality that exists among AB polarity regulators. Regarding this latter theme, we provide further discussion of the potential plasticity of the cell polarity machinery and as a result the possible implications for human disease. PMID:25469537

  7. Unique Structural and Nucleotide Exchange Features of the Rho1 GTPase of Entamoeba histolytica

    SciTech Connect

    Bosch, Dustin E.; Wittchen, Erika S.; Qiu, Connie; Burridge, Keith; Siderovski, David P.

    2012-08-10

    The single-celled human parasite Entamoeba histolytica possesses a dynamic actin cytoskeleton vital for its intestinal and systemic pathogenicity. The E. histolytica genome encodes several Rho family GTPases known to regulate cytoskeletal dynamics. EhRho1, the first family member identified, was reported to be insensitive to the Rho GTPase-specific Clostridium botulinum C3 exoenzyme, raising the possibility that it may be a misclassified Ras family member. Here, we report the crystal structures of EhRho1 in both active and inactive states. EhRho1 is activated by a conserved switch mechanism, but diverges from mammalian Rho GTPases in lacking a signature Rho insert helix. EhRho1 engages a homolog of mDia, EhFormin1, suggesting a role in mediating serum-stimulated actin reorganization and microtubule formation during mitosis. EhRho1, but not a constitutively active mutant, interacts with a newly identified EhRhoGDI in a prenylation-dependent manner. Furthermore, constitutively active EhRho1 induces actin stress fiber formation in mammalian fibroblasts, thereby identifying it as a functional Rho family GTPase. EhRho1 exhibits a fast rate of nucleotide exchange relative to mammalian Rho GTPases due to a distinctive switch one isoleucine residue reminiscent of the constitutively active F28L mutation in human Cdc42, which for the latter protein, is sufficient for cellular transformation. Nonconserved, nucleotide-interacting residues within EhRho1, revealed by the crystal structure models, were observed to contribute a moderating influence on fast spontaneous nucleotide exchange. Collectively, these observations indicate that EhRho1 is a bona fide member of the Rho GTPase family, albeit with unique structural and functional aspects compared with mammalian Rho GTPases.

  8. Phosphorylation and Activation of RhoA by ERK in Response to Epidermal Growth Factor Stimulation.

    PubMed

    Tong, Junfeng; Li, Laiji; Ballermann, Barbara; Wang, Zhixiang

    2016-01-01

    The small GTPase RhoA has been implicated in various cellular activities, including the formation of stress fibers, cell motility, and cytokinesis. In addition to the canonical GTPase cycle, recent findings have suggested that phosphorylation further contributes to the tight regulation of Rho GTPases. Indeed, RhoA is phosphorylated on serine 188 (188S) by a number of protein kinases. We have recently reported that Rac1 is phosphorylated on threonine 108 (108T) by extracellular signal-regulated kinases (ERK) in response to epidermal growth factor (EGF) stimulation. Here, we provide evidence that RhoA is phosphorylated by ERK on 88S and 100T in response to EGF stimulation. We show that ERK interacts with RhoA and that this interaction is dependent on the ERK docking site (D-site) at the C-terminus of RhoA. EGF stimulation enhanced the activation of the endogenous RhoA. The phosphomimetic mutant, GFP-RhoA S88E/T100E, when transiently expressed in COS-7 cells, displayed higher GTP-binding than wild type RhoA. Moreover, the expression of GFP-RhoA S88E/T100E increased actin stress fiber formation in COS-7 cells, which is consistent with its higher activity. In contrast to Rac1, phosphorylation of RhoA by ERK does not target RhoA to the nucleus. Finally, we show that regardless of the phosphorylation status of RhoA and Rac1, substitution of the RhoA PBR with the Rac1 PBR targets RhoA to the nucleus and substitution of Rac1 PBR with RhoA PBR significantly reduces the nuclear localization of Rac1. In conclusion, ERK phosphorylates RhoA on 88S and 100T in response to EGF, which upregulates RhoA activity. PMID:26816343

  9. Phosphorylation and Activation of RhoA by ERK in Response to Epidermal Growth Factor Stimulation

    PubMed Central

    Tong, Junfeng; Li, Laiji; Ballermann, Barbara; Wang, Zhixiang

    2016-01-01

    The small GTPase RhoA has been implicated in various cellular activities, including the formation of stress fibers, cell motility, and cytokinesis. In addition to the canonical GTPase cycle, recent findings have suggested that phosphorylation further contributes to the tight regulation of Rho GTPases. Indeed, RhoA is phosphorylated on serine 188 (188S) by a number of protein kinases. We have recently reported that Rac1 is phosphorylated on threonine 108 (108T) by extracellular signal-regulated kinases (ERK) in response to epidermal growth factor (EGF) stimulation. Here, we provide evidence that RhoA is phosphorylated by ERK on 88S and 100T in response to EGF stimulation. We show that ERK interacts with RhoA and that this interaction is dependent on the ERK docking site (D-site) at the C-terminus of RhoA. EGF stimulation enhanced the activation of the endogenous RhoA. The phosphomimetic mutant, GFP-RhoA S88E/T100E, when transiently expressed in COS-7 cells, displayed higher GTP-binding than wild type RhoA. Moreover, the expression of GFP-RhoA S88E/T100E increased actin stress fiber formation in COS-7 cells, which is consistent with its higher activity. In contrast to Rac1, phosphorylation of RhoA by ERK does not target RhoA to the nucleus. Finally, we show that regardless of the phosphorylation status of RhoA and Rac1, substitution of the RhoA PBR with the Rac1 PBR targets RhoA to the nucleus and substitution of Rac1 PBR with RhoA PBR significantly reduces the nuclear localization of Rac1. In conclusion, ERK phosphorylates RhoA on 88S and 100T in response to EGF, which upregulates RhoA activity. PMID:26816343

  10. Coherent rho 0 photoproduction in bulk matter at high energies

    SciTech Connect

    Couderc, Elsa; Klein, Spencer

    2009-01-09

    The momentum transfer {Delta}k required for a photon to scatter from a target and emerge as a {rho}{sup 0} decreases as the photon energy k rises. For k > 3 x 10{sup 14} eV, {Delta}k is small enough that the interaction cannot be localized to a single nucleus. At still higher energies, photons may coherently scatter elastically from bulk matter and emerge as a {rho}{sup 0}, in a manner akin to kaon regeneration. Constructive interference from the different nuclei coherently raises the cross section and the interaction probability rises linearly with energy. At energies above 10{sup 23} eV, coherent conversion is the dominant process; photons interact predominantly as {rho}{sup 0}. We compute the coherent scattering probabilities in slabs of lead, water and rock, and discuss the implications of the increased hadronic interaction probabilities for photons on ultra-high energy shower development.

  11. Rho-modifying bacterial protein toxins from Photorhabdus species.

    PubMed

    Jank, Thomas; Lang, Alexander E; Aktories, Klaus

    2016-06-15

    Photorhabdus bacteria live in symbiosis with entomopathogenic nematodes. The nematodes invade insect larvae, where they release the bacteria, which then produce toxins to kill the insects. Recently, the molecular mechanisms of some toxins from Photorhabdus luminescens and asymbiotica have been elucidated, showing that GTP-binding proteins of the Rho family are targets. The tripartite Tc toxin PTC5 from P. luminescens activates Rho proteins by ADP-ribosylation of a glutamine residue, which is involved in GTP hydrolysis, while PaTox from Photorhabdus asymbiotica inhibits the activity of GTPases by N-acetyl-glucosaminylation at tyrosine residues and activates Rho proteins indirectly by deamidation of heterotrimeric G proteins. PMID:26026623

  12. Involvement of inhibition of RhoA/Rho kinase signaling in simvastatin-induced amelioration of neuropathic pain.

    PubMed

    Ohsawa, Masahiro; Ishikura, Kei-Ichiro; Mutoh, Junpei; Hisa, Hiroaki

    2016-10-01

    Small molecular G-protein plays a key role in several diseases. This study was designed to reveal the role of RhoA signaling in the pathophysiology of neuropathic pain in mice. Partial sciatic nerve injury caused thermal hyperalgesia, mechanical allodynia, and increased plasma membrane translocation of RhoA in the lumber spinal cord. GFAP-immunoreactivity (ir), Iba-1-ir, and Rho kinase 2 (ROCK2-ir) was also increased in the ipsilateral spinal dorsal horn of nerve-ligated mice. Moreover, partial nerve ligation increased the expression of phosphorylated myristoylated alanine-rich protein kinase C substrate (MARCKS)-ir in the ipsilateral spinal dorsal horn. Daily intrathecal administration of simvastatin, beginning 3days before nerve injury, completely blocked all these changes in nerve-ligated mice. Pharmacological inhibition of ROCK also attenuated the increased expression of GFAP-ir and phosphorylated MARCKS-ir. Together, it is suggested that astrogliosis initiated by the activation of RhoA/ROCK signaling results in MARCKS phosphorylation in nerve terminals, which leads to hyperalgesia in neuropathic pain. Furthermore, simvastatin exerts antihyperalgesic and antiallodynic effects through the inhibition of spinal RhoA activation. PMID:27457035

  13. Branching fraction measurements of B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma.

    PubMed

    Aubert, B; Bona, M; Boutigny, D; Karyotakis, Y; Lees, J P; Poireau, V; Prudent, X; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lopes Pegna, D; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Tackmann, K; Wenzel, W A; del Amo Sanchez, P; Barrett, M; Harrison, T J; Hart, A J; Hawkes, C M; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Asgeirsson, D J; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Martin, E C; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Liu, F; Long, O; Shen, B C; Zhang, L; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Schalk, T; Schumm, B A; Seiden, A; Williams, D C; Wilson, M G; Winstrom, L O; Chen, E; Cheng, C H; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Merkel, J; Petzold, A; Spaan, B; Wacker, K; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Dauncey, P D; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Lepeltier, V; Le Diberder, F; Lutz, A M; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Serrano, J; Stocchi, A; Wang, W F; Wormser, G; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; George, K A; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; West, T J; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Salvati, E; Saremi, S; Cowan, R; Koeneke, K; Lang, M I; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Yi, M; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Benelli, G; Corwin, L A; Gan, K K; Honscheid, K; Hufnagel, D; Kagan, H; Kass, R; Morris, J P; Rahimi, A M; Regensburger, J J; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Kolb, J A; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Ben-Haim, E; Briand, H; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; Leruste, Ph; Malclès, J; Ocariz, J; Gladney, L; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Biesiada, J; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Jackson, P D; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; Castelli, G; Franek, B; Olaiya, E O; Ricciardi, S; Roethel, W; Wilson, F F; Aleksan, R; Emery, S; Escalier, M; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Grenier, P; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Wagner, A P; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Wulsin, H W; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Pelliccioni, M; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Lanceri, L; Vitale, L; Azzolini, V; Lopez-March, N; Martinez-Vidal, F; Oyanguren, A; Albert, J; Banerjee, Sw; Bhuyan, B; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Dasu, S; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-04-13

    We present a study of the decays B+-->rho+gamma, B0-->rho0gamma, and B0-->omegagamma. The analysis is based on data containing 347 x 10(6) BB[over ] events recorded with the BABAR detector at the PEP-II asymmetric B factory. We measure the branching fractions B(B+-->rho+)gamma)=(1.10_(-0.33)(+0.37)+/-0.09)x10(-6) and B(B0-->rho0gamma)=(0.79(-0.20)(+0.22)+/-0.06)x10(-6), and set a 90% C.L. upper limit B(B0-->omegagamma)<0.78 x 10(-6). We also measure the isospin-averaged branching fraction B(B-->(rho/omega)gamma)=(1.25(-0.24)(+0.25)+/-0.09)x10(-6), from which we determine |Vtd/Vts|=0.200(-0.020)(+0.021)+/-0.015, where the first uncertainty is experimental and the second is theoretical. PMID:17501336

  14. Impacts of Rho kinase inhibitor Fasudil on Rho/ROCK signaling pathway in rabbits with optic nerve injury

    PubMed Central

    Yu, Jianglong; Lin, Lin; Luan, Xinping; Jing, Xiepan; Maierab

    2015-01-01

    Objective: The aim of this study was to study the impacts of Rho kinase inhibitor Fasudil on expressions of Rho/ROCK signaling pathway associated genes in rabbits with optic nerve injury (ONI), and to explore the therapeutic mechanisms towards ONI. Methods: The rabbit ONI model was established, then the rabbits were divided into model group (treated with saline), control group (treated with dexamethasone, Dex), and intervention group (treated with Fasudil, Fas). The eyeball and optic nerve were sampled at 3, 7, 14 and 21 days after injury. The morphological changes of retina and optic nerve were observed. The expressions of RhoA, Caspase-3, Rock 2 and Nogo-A gene were determined by immunohistochemistry and real-time polymerase chain reaction (RT-PCR) methods. Results: At different time after injury, there were significant differences of RhoA, Caspase-3, Rock 2 and Nogo-A gene expression among three groups (P < 0.05). Conclusions: After ONI, Fas can decrease the expression of Caspase-3 gene, and down-regulate the expressions of Nogo-A and Rock 2 gene. Therefore, it can treat ONI through affecting the Rho/ROCK signaling pathway. PMID:26823796

  15. Observation of e(+)e(-) annihilation into the C = +1 hadronic final states rho(0)rho(0) and phirho(0).

    PubMed

    Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Del Amo Sanchez, P; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Goetzen, K; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, Ch; Verderi, M; Bard, D J; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Lu, M; Potter, C T; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Galeazzi, F; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; David, P; Del Buono, L; de la Vaissière, Ch

    2006-09-15

    We report the first observation of e(+)e(-) annihilation into states of positive C parity, namely, rho(0)rho(0) and phirho(0). The two states are observed in the pi(+)pi(-)pi(+)pi(-) and K(+)K(-)pi(+)pi(-) final states, respectively, in a data sample of 225 fb(-1) collected by the BABAR experiment at the Positron-Electron Project II e(+)e(-) storage rings at energies near sqrt[s]=10.58 GeV. The distributions of costheta(*), where theta(*) is the center-of-mass polar angle of the phi meson or the forward rho(0) meson, suggest production by two-virtual-photon annihilation. We measure cross sections within the range |costheta(*)|<0.8 of sigma(e(+)e(-)-->rho(0)rho(0))=20.7+/-0.7(stat)+/-2.7(syst) fb and sigma(e(+)e(-)-->phirho(0))=5.7+/-0.5(stat)+/-0.8(syst) fb. PMID:17025878

  16. Foam-stabilizing effects and cling formation patterns of iso-alpha-acids and reduced iso-alpha-acids in lager beer.

    PubMed

    Kunimune, Takeshi; Shellhammer, Thomas H

    2008-09-24

    Foam-stabilizing properties and cling formation patterns of iso-alpha-acids and reduced iso-alpha-acids were investigated using an unhopped lager beer. Unhopped beer was dosed with iso-alpha-acid (Iso), rho-iso-alpha-acid (Rho), tetrahydro-iso-alpha-acid (Tetra), and hexahydro-iso-alpha-acid (Hexa), separately, over a range of concentrations from 2 to 10 ppm. A uniform foam was created by Inpack 2000 Flasher Head and was measured by a NIBEM Foam Stability Tester (NIBEM-TPH) followed by a NIBEM Cling Meter (NIBEM-CLM) to determine the relationship between the concentration and NIBEM-30 and the cling formation ability of each compound. The foam-stabilizing power was determined to be Tetra, Hexa, Iso, and Rho from the strongest to weakest. Linear regression models were created using the NIBEM-TPH data set, and on the basis of 95% confidence intervals, the foam stability of Tetra or Hexa became significantly larger than that of Iso when 2.4 or 4.2 ppm of Tetra or Hexa was used as a replacement for Iso, respectively. Cling formation patterns could be categorized into three groups: "ring", "mesh", and "powdery". The control beer had the lowest foam stability and did not yield any foam cling. PMID:18729457

  17. Discovery of new 2 micron sources in Rho Ophiuchi

    NASA Technical Reports Server (NTRS)

    Barsony, M.; Carlstrom, J. E.; Burton, Michael G.; Russell, A. P. G.; Garden, R.

    1989-01-01

    A 144-sq-arcmin region of the Rho Oph star-forming cloud core was surveyed at 2.2 microns, complete to mK = 14. A total of 61 sources are detected, 26 of which have been previously reported, accounting for a total of 35 new sources with mK = 12-14. There is no turnover in the 2-micron luminosity function of the Rho Oph cloud core to a limiting sensitivity of mK = 14. Two of the newly discovered sources are binary companions to previously cataloged objects.

  18. The interstellar carbon abundance. II - Rho Ophiuchi and Beta Scorpii

    NASA Technical Reports Server (NTRS)

    Welty, D. E.; York, D. G.; Hobbs, L. M.

    1986-01-01

    A procedure designed to obtain increased sensitivity from high-dispersion IUE spectra by using a flat-field spectrum to remove nonrandom noise due to the response pattern of the SEC vidicon detector is described. Application of this procedure to spectra of Rho Oph and Beta(1) Sco near the spin-forbidden interstellar 2325 line of C II yields 2 sigma upper limits on absorption of W (lambda) not greater than about 4 mA. The resulting depletion of carbon from the interstellar gas toward Rho Oph exceeds a factor of 1.4.

  19. The Rho GTPase Family Genes in Bivalvia Genomes: Sequence, Evolution and Expression Analysis

    PubMed Central

    Li, Xue; Wang, Ruijia; Xun, Xiaogang; Jiao, Wenqian; Zhang, Mengran; Wang, Shuyue; Wang, Shi; Zhang, Lingling; Huang, Xiaoting; Hu, Xiaoli; Bao, Zhenmin

    2015-01-01

    Background Rho GTPases are important members of the Ras superfamily, which represents the largest signaling protein family in eukaryotes, and function as key molecular switches in converting and amplifying external signals into cellular responses. Although numerous analyses of Rho family genes have been reported, including their functions and evolution, a systematic analysis of this family has not been performed in Mollusca or in Bivalvia, one of the most important classes of Mollusca. Results In this study, we systematically identified and characterized a total set (Rho, Rac, Mig, Cdc42, Tc10, Rnd, RhoU, RhoBTB and Miro) of thirty Rho GTPase genes in three bivalve species, including nine in the Yesso scallop Patinopecten yessoensis, nine in the Zhikong scallop Chlamys farreri, and twelve in the Pacific oyster Crassostrea gigas. Phylogenetic analysis and interspecies comparison indicated that bivalves might possess the most complete types of Rho genes in invertebrates. A multiple RNA-seq dataset was used to investigate the expression profiles of bivalve Rho genes, revealing that the examined scallops share more similar Rho expression patterns than the oyster, whereas more Rho mRNAs are expressed in C. farreri and C. gigas than in P. yessoensis. Additionally, Rho, Rac and Cdc42 were found to be duplicated in the oyster but not in the scallops. Among the expanded Rho genes of C. gigas, duplication pairs with high synonymous substitution rates (Ks) displayed greater differences in expression. Conclusion A comprehensive analysis of bivalve Rho GTPase family genes was performed in scallop and oyster species, and Rho genes in bivalves exhibit greater conservation than those in any other invertebrate. This is the first study focusing on a genome-wide characterization of Rho GTPase genes in bivalves, and the findings will provide a valuable resource for a better understanding of Rho evolution and Rho GTPase function in Bivalvia. PMID:26633655

  20. RhoJ interacts with the GIT-PIX complex and regulates focal adhesion disassembly.

    PubMed

    Wilson, Eleanor; Leszczynska, Katarzyna; Poulter, Natalie S; Edelmann, Francesca; Salisbury, Victoria A; Noy, Peter J; Bacon, Andrea; Rappoport, Joshua Z; Heath, John K; Bicknell, Roy; Heath, Victoria L

    2014-07-15

    RhoJ is a Rho GTPase expressed in endothelial cells and tumour cells, which regulates cell motility, invasion, endothelial tube formation and focal adhesion numbers. This study aimed to further delineate the molecular function of RhoJ. Using timelapse microscopy RhoJ was found to regulate focal adhesion disassembly; small interfering RNA (siRNA)-mediated knockdown of RhoJ increased focal adhesion disassembly time, whereas expression of an active mutant (daRhoJ) decreased it. Furthermore, daRhoJ co-precipitated with the GIT-PIX complex, a regulator of focal adhesion disassembly. An interaction between daRhoJ and GIT1 was confirmed using yeast two-hybrid experiments, and this depended on the Spa homology domain of GIT1. GIT1, GIT2, β-PIX (also known as ARHGEF7) and RhoJ all colocalised in focal adhesions and depended on each other for their recruitment to focal adhesions. Functionally, the GIT-PIX complex regulated endothelial tube formation, with knockdown of both GIT1 and GIT2, or β-PIX phenocopying RhoJ knockdown. RhoJ-knockout mice showed reduced tumour growth and diminished tumour vessel density, identifying a role for RhoJ in mediating tumour angiogenesis. These studies give new insight into the molecular function of RhoJ in regulating cell motility and tumour vessel formation. PMID:24928894

  1. The Role of RhoJ in Endothelial Cell Biology and Tumor Pathology

    PubMed Central

    Shi, Ting-Ting; Li, Gang

    2016-01-01

    Background. RhoJ, an endothelially expressed member of Cdc42 (cell division cycle 42) subfamily of Rho GTPase, plays an important role in endocytic pathway, adipocyte differentiation, endothelial motility, tube formation, and focal adhesion. RhoJ is a selective and effective therapeutic target in tumor tissues or retinopathy. Methods. A systematic review was related to “small Rho GTPase” or “RhoJ” with “endothelial motility, tube formation and focal adhesion” and “tumor therapy”. This led to many cross-references involving RhoJ and these data have been incorporated into the following study. Results. We have grouped the role of RhoJ according to three main effects: RhoJ regulates endocytic pathway and adipocyte differentiation in early studies, and RhoJ shows an important role in endothelial cell biology; furthermore, RhoJ blockade serves as a target in tumor vasculature and enhances the effects of anticancer drug. Conclusions. More research is necessary to understand the role of RhoJ in many aspects, on the basis of current knowledge of the role of RhoJ blockade in tumor vessels, there are opportunities for the therapy of tumor, and RhoJ is expressed outside tumour vasculature and is involved in wound healing. Taking advantage of the opportunities could result in a development in tumor therapy. PMID:27556037

  2. A physical model for the translocation and helicase activities of Escherichia coli transcription termination protein Rho.

    PubMed Central

    Geiselmann, J; Wang, Y; Seifried, S E; von Hippel, P H

    1993-01-01

    Transcription termination protein Rho of Escherichia coli interacts with newly synthesized RNA chains and brings about their release from elongation complexes paused at specific Rho-dependent termination sites. Rho is thought to accomplish this by binding to a specific Rho "loading site" on the nascent RNA and then translocating preferentially along the transcript in a 5'-->3' direction. On reaching the elongation complex, Rho releases the nascent RNA by a 5'-->3' RNA.DNA helicase activity. These translocation and helicase activities are driven by the RNA-dependent ATPase activity of Rho. In this paper we propose a mechanism for these processes that is based on the structure and properties of the Rho protein. Rho is a hexamer of identical subunits that are arranged as a trimer of asymmetric dimers with D3 symmetry. The binding of ATP and RNA to Rho also reflects this pattern; the Rho hexamer carries three strong and three weak binding sites for each of these entities. The asymmetric dimers of Rho correspond to functional dimers that can undergo conformational transitions driven by ATP hydrolysis. We propose that the quaternary structure of Rho coordinates the ATP-driven RNA binding and release processes to produce a biased random walk of the Rho hexamer along the RNA, followed by RNA.DNA helicase activity and transcript release. The proposed model may have implications for other hexameric DNA.DNA, RNA.DNA, and RNA.RNA helicases that function in replication and transcription. Images Fig. 2 PMID:7689228

  3. RhoG protein regulates platelet granule secretion and thrombus formation in mice.

    PubMed

    Goggs, Robert; Harper, Matthew T; Pope, Robert J; Savage, Joshua S; Williams, Christopher M; Mundell, Stuart J; Heesom, Kate J; Bass, Mark; Mellor, Harry; Poole, Alastair W

    2013-11-22

    Rho GTPases such as Rac, RhoA, and Cdc42 are vital for normal platelet function, but the role of RhoG in platelets has not been studied. In other cells, RhoG orchestrates processes integral to platelet function, including actin cytoskeletal rearrangement and membrane trafficking. We therefore hypothesized that RhoG would play a critical role in platelets. Here, we show that RhoG is expressed in human and mouse platelets and is activated by both collagen-related peptide (CRP) and thrombin stimulation. We used RhoG(-/-) mice to study the function of RhoG in platelets. Integrin activation and aggregation were reduced in RhoG(-/-) platelets stimulated by CRP, but responses to thrombin were normal. The central defect in RhoG(-/-) platelets was reduced secretion from α-granules, dense granules, and lysosomes following CRP stimulation. The integrin activation and aggregation defects could be rescued by ADP co-stimulation, indicating that they are a consequence of diminished dense granule secretion. Defective dense granule secretion in RhoG(-/-) platelets limited recruitment of additional platelets to growing thrombi in flowing blood in vitro and translated into reduced thrombus formation in vivo. Interestingly, tail bleeding times were normal in RhoG(-/-) mice, suggesting that the functions of RhoG in platelets are particularly relevant to thrombotic disorders. PMID:24106270

  4. RhoG Protein Regulates Platelet Granule Secretion and Thrombus Formation in Mice*

    PubMed Central

    Goggs, Robert; Harper, Matthew T.; Pope, Robert J.; Savage, Joshua S.; Williams, Christopher M.; Mundell, Stuart J.; Heesom, Kate J.; Bass, Mark; Mellor, Harry; Poole, Alastair W.

    2013-01-01

    Rho GTPases such as Rac, RhoA, and Cdc42 are vital for normal platelet function, but the role of RhoG in platelets has not been studied. In other cells, RhoG orchestrates processes integral to platelet function, including actin cytoskeletal rearrangement and membrane trafficking. We therefore hypothesized that RhoG would play a critical role in platelets. Here, we show that RhoG is expressed in human and mouse platelets and is activated by both collagen-related peptide (CRP) and thrombin stimulation. We used RhoG−/− mice to study the function of RhoG in platelets. Integrin activation and aggregation were reduced in RhoG−/− platelets stimulated by CRP, but responses to thrombin were normal. The central defect in RhoG−/− platelets was reduced secretion from α-granules, dense granules, and lysosomes following CRP stimulation. The integrin activation and aggregation defects could be rescued by ADP co-stimulation, indicating that they are a consequence of diminished dense granule secretion. Defective dense granule secretion in RhoG−/− platelets limited recruitment of additional platelets to growing thrombi in flowing blood in vitro and translated into reduced thrombus formation in vivo. Interestingly, tail bleeding times were normal in RhoG−/− mice, suggesting that the functions of RhoG in platelets are particularly relevant to thrombotic disorders. PMID:24106270

  5. Measurements of Charmless B Decays Related to alpha at BaBar

    SciTech Connect

    Lombardo, Vincenzo; /INFN, Milan

    2009-12-09

    We report recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory. In addition to improved constraints on {alpha} from the decays B{sup {+-}} {yields} {rho}{sup {+-}}{rho}{sup 0}, we also present preliminary results of neutral and charged B meson decays to K{sub 1}(1270){pi} and K{sub 1}(1400){pi} and its impact on the estimate for the CKM angle {alpha} based on time-dependent analysis of CP-violating asymmetries in B{sup 0} {yields} a{sub 1}(1260){sup {+-}} {pi}{sup {-+}}. Moreover we report the first observation of the decay B {yields} a{sub 1}(1260){sup {+-}}a{sub 1}(1260){sup {-+}}; this mode can be used, in principle, to provide an independent measurement of {alpha}.

  6. Interaction between the Type III Effector VopO and GEF-H1 Activates the RhoA-ROCK Pathway

    PubMed Central

    Hiyoshi, Hirotaka; Okada, Ryu; Matsuda, Shigeaki; Gotoh, Kazuyoshi; Akeda, Yukihiro; Iida, Tetsuya; Kodama, Toshio

    2015-01-01

    Vibrio parahaemolyticus is an important pathogen that causes food-borne gastroenteritis in humans. The type III secretion system encoded on chromosome 2 (T3SS2) plays a critical role in the enterotoxic activity of V. parahaemolyticus. Previous studies have demonstrated that T3SS2 induces actin stress fibers in various epithelial cell lines during infection. This stress fiber formation is strongly related to pathogenicity, but the mechanisms that underlie T3SS2-dependent actin stress fiber formation and the main effector have not been elucidated. In this study, we identified VopO as a critical T3SS2 effector protein that activates the RhoA-ROCK pathway, which is an essential pathway for the induction of the T3SS2-dependent stress fiber formation. We also determined that GEF-H1, a RhoA guanine nucleotide exchange factor (GEF), directly binds VopO and is necessary for T3SS2-dependent stress fiber formation. The GEF-H1-binding activity of VopO via an alpha helix region correlated well with its stress fiber-inducing capacity. Furthermore, we showed that VopO is involved in the T3SS2-dependent disruption of the epithelial barrier. Thus, VopO hijacks the RhoA-ROCK pathway in a different manner compared with previously reported bacterial toxins and effectors that modulate the Rho GTPase signaling pathway. PMID:25738744

  7. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... Liver Disease Information > Alpha-1 Antitrypsin Deficiency Alpha-1 Antitrypsin Deficiency Explore this section to learn more about alpha-1 antitrypsin deficiency, including a description of the disorder ...

  8. High-energy photoproduction of rho and phi vector mesons

    SciTech Connect

    Callahan, P.H.

    1983-01-01

    We have studied the photoproduction of rho and phi vector mesons from hydrogen in the Fermilab broad band neutral beam. Forward going two particle final states were detected in a multiparticle spectrometer consisting of two analyzing magnets, a multiwire-proportional-chamber tracking system and a particle identification system. Recoil protons and target fragments were observed in a recoil detector which surrounded the target. The total elastic cross-sections were measured to be independent of energy at the 10% level from 35 to 225 GeV at 10.6 ..mu..b for the rho and from 35 to 165 GeV at 0.64 ..mu..b for the phi. The elastic differential cross-sections were also measured. Approximately 20% of the diffractive rho and phi events were found to be inelastic from an analysis of the recoil detector. The t-dependence of the fraction of diffractive events which are inelastic for both the phi and the psi are consistent with a universal function determined from the rho data.

  9. Rho kinase as a therapeutic target in cardiovascular disease

    PubMed Central

    Surma, Michelle; Wei, Lei; Shi, Jianjian

    2011-01-01

    Rho kinase (ROCK) belongs to the AGC (PKA/PKG/PKC) family of serine/threonine kinases and is a major downstream effector of the small GTPase RhoA. ROCK plays central roles in the organization of the actin cytoskeleton and is involved in a wide range of fundamental cellular functions such as contraction, adhesion, migration, proliferation and gene expression. Two ROCK isoforms, ROCK1 a n d ROCK2, are assumed to be functionally redundant, based largely on the major common activators, the high degree of homology within the kinase domain and studies from overexpression with kinase constructs a n d chemical inhibitors (e.g., Y27632 a n d fasudil), which inhibit both ROCK1 and ROCK2. Extensive experimental a n d clinical studies support a critical role for the RhoA/ROCK pathway in the vascular bed in the pathogenesis of cardiovascular diseases, in which increased ROCK activity mediates vascular smooth muscle cell hypercontraction, endothelial dysfunction, inflammatory cell recruitment and vascular remodeling. Recent experimental studies, using ROCK inhibitors or genetic mouse models, indicate that the RhoA/ROCK pathway in myocardium contributes to cardiac remodeling induced by ischemic injury or persistent hypertrophic stress, thereby leading to cardiac decompensation and heart failure. This article, based on recent molecular, cellular and animal studies, focuses on the current understanding of ROCK signaling in cardiovascular diseases and in the pathogenesis of heart failure. PMID:21929346

  10. Structural Mechanisms and Drug Discovery Prospects of Rho GTPases

    PubMed Central

    Smithers, Cameron C.; Overduin, Michael

    2016-01-01

    Rho GTPases regulate cellular morphology and dynamics, and some are key drivers of cancer progression. This superfamily offers attractive potential targets for therapeutic intervention, with RhoA, Rac1 and Cdc42 being prime examples. The challenges in developing agents that act on these signaling enzymes include the lack of obvious druggable pockets and their membrane-bound activities. However, progress in targeting the similar Ras protein is illuminating new strategies for specifically inhibiting oncogenic GTPases. The structures of multiple signaling and regulatory states of Rho proteins have been determined, and the post-translational modifications including acylation and phosphorylation points have been mapped and their functional effects examined. The development of inhibitors to probe the significance of overexpression and mutational hyperactivation of these GTPases underscores their importance in cancer progression. The ability to integrate in silico, in vitro, and in vivo investigations of drug-like molecules indicates the growing tractability of GTPase systems for lead optimization. Although no Rho-targeted drug molecules have yet been clinically approved, this family is clearly showing increasing promise for the development of precision medicine and combination cancer therapies. PMID:27304967

  11. Epithelial junctions and Rho family GTPases: the zonular signalosome

    PubMed Central

    Citi, Sandra; Guerrera, Diego; Spadaro, Domenica; Shah, Jimit

    2014-01-01

    The establishment and maintenance of epithelial cell-cell junctions is crucially important to regulate adhesion, apico-basal polarity and motility of epithelial cells, and ultimately controls the architecture and physiology of epithelial organs. Junctions are supported, shaped and regulated by cytoskeletal filaments, whose dynamic organization and contractility are finely tuned by GTPases of the Rho family, primarily RhoA, Rac1 and Cdc42. Recent research has identified new molecular mechanisms underlying the cross-talk between these GTPases and epithelial junctions. Here we briefly summarize the current knowledge about the organization, molecular evolution and cytoskeletal anchoring of cell-cell junctions, and we comment on the most recent advances in the characterization of the interactions between Rho GTPases and junctional proteins, and their consequences with regards to junction assembly and regulation of cell behavior in vertebrate model systems. The concept of “zonular signalosome” is proposed, which highlights the close functional relationship between proteins of zonular junctions (zonulae occludentes and adhaerentes) and the control of cytoskeletal organization and signaling through Rho GTPases, transcription factors, and their effectors. PMID:25483301

  12. Structural Mechanisms and Drug Discovery Prospects of Rho GTPases.

    PubMed

    Smithers, Cameron C; Overduin, Michael

    2016-01-01

    Rho GTPases regulate cellular morphology and dynamics, and some are key drivers of cancer progression. This superfamily offers attractive potential targets for therapeutic intervention, with RhoA, Rac1 and Cdc42 being prime examples. The challenges in developing agents that act on these signaling enzymes include the lack of obvious druggable pockets and their membrane-bound activities. However, progress in targeting the similar Ras protein is illuminating new strategies for specifically inhibiting oncogenic GTPases. The structures of multiple signaling and regulatory states of Rho proteins have been determined, and the post-translational modifications including acylation and phosphorylation points have been mapped and their functional effects examined. The development of inhibitors to probe the significance of overexpression and mutational hyperactivation of these GTPases underscores their importance in cancer progression. The ability to integrate in silico, in vitro, and in vivo investigations of drug-like molecules indicates the growing tractability of GTPase systems for lead optimization. Although no Rho-targeted drug molecules have yet been clinically approved, this family is clearly showing increasing promise for the development of precision medicine and combination cancer therapies. PMID:27304967

  13. Rho-signaling pathways in chronic myelogenous leukemia.

    PubMed

    Kuzelová, Katerina; Hrkal, Zbynēk

    2008-12-01

    Chronic myelogenous leukemia (CML) is a hematological malignancy that is characteristic by as expansion of myeloid cells and their premature release into the circulation. The molecular cause of CML is the fusion oncoprotein Bcr-Abl whose constitutive tyrosine-kinase (TK) activity maintains enhanced signaling through multiple signal transduction pathways and confers proliferative and survival advantage to CML cells. These effects can be largely suppressed by TK inhibitor Imatinib mesylate, currently the leading drug in CML treatment. However, Bcr-Abl contains also additional functional domains, in particular a DBL homology (DH) domain with guanine-exchange function (GEF) which can activate small GTPases of Rho family and a Src-homology3 (SH3) domain which recruits other proteins with GEF activity. Bcr-Abl affects among others the RhoA/ROCK/LIM/cofilin pathway that regulates the actin cytoskeleton assembly and thereby the cellular adhesion and migration. This review deals in detail with the known points of interference between Bcr-Abl and Rho kinase pathways and with the effects of Imatinib mesylate on Rho signaling and cell adhesion to the extracellular matrix (ECM) components. The potential protein targets related to Bcr-Abl non-kinase activity are discussed. PMID:19075636

  14. AMPylation of Rho GTPases Subverts Multiple Host Signaling Processes*

    PubMed Central

    Woolery, Andrew R.; Yu, Xiaobo; LaBaer, Joshua; Orth, Kim

    2014-01-01

    Rho GTPases are frequent targets of virulence factors as they are keystone signaling molecules. Herein, we demonstrate that AMPylation of Rho GTPases by VopS is a multifaceted virulence mechanism that counters several host immunity strategies. Activation of NFκB, Erk, and JNK kinase signaling pathways were inhibited in a VopS-dependent manner during infection with Vibrio parahaemolyticus. Phosphorylation and degradation of IKBα were inhibited in the presence of VopS as was nuclear translocation of the NFκB subunit p65. AMPylation also prevented the generation of superoxide by the phagocytic NADPH oxidase complex, potentially by inhibiting the interaction of Rac and p67. Furthermore, the interaction of GTPases with the E3 ubiquitin ligases cIAP1 and XIAP was hindered, leading to decreased degradation of Rac and RhoA during infection. Finally, we screened for novel Rac1 interactions using a nucleic acid programmable protein array and discovered that Rac1 binds to the protein C1QA, a protein known to promote immune signaling in the cytosol. Interestingly, this interaction was disrupted by AMPylation. We conclude that AMPylation of Rho Family GTPases by VopS results in diverse inhibitory consequences during infection beyond the most obvious phenotype, the collapse of the actin cytoskeleton. PMID:25301945

  15. Rho kinase signaling pathways during stretch in primary alveolar epithelia.

    PubMed

    DiPaolo, Brian C; Margulies, Susan S

    2012-05-15

    Alveolar epithelial cells (AECs) maintain integrity of the blood-gas barrier with actin-anchored intercellular tight junctions. Stretched type I-like AECs undergo magnitude- and frequency-dependent actin cytoskeletal remodeling into perijunctional actin rings. On the basis of published studies in human pulmonary artery endothelial cells (HPAECs), we hypothesize that RhoA activity, Rho kinase (ROCK) activity, and phosphorylation of myosin light chain II (MLC2) increase in stretched type I-like AECs in a manner that is dependent on stretch magnitude, and that RhoA, ROCK, or MLC2 activity inhibition will attenuate stretch-induced actin remodeling and preserve barrier properties. Primary type I-like AEC monolayers were stretched biaxially to create a change in surface area (ΔSA) of 12%, 25%, or 37% in a cyclic manner at 0.25 Hz for up to 60 min or left unstretched. Type I-like AECs were also treated with Rho pathway inhibitors (ML-7, Y-27632, or blebbistatin) and stained for F-actin or treated with the myosin phosphatase inhibitor calyculin-A and quantified for monolayer permeability. Counter to our hypothesis, ROCK activity and MLC2 phosphorylation decreased in type I-like AECs stretched to 25% and 37% ΔSA and did not change in monolayers stretched to 12% ΔSA. Furthermore, RhoA activity decreased in type I-like AECs stretched to 37% ΔSA. In contrast, MLC2 phosphorylation in HPAECs increased when HPAECs were stretched to 12% ΔSA but then decreased when they were stretched to 37% ΔSA, similar to type I-like AECs. Perijunctional actin rings were observed in unstretched type I-like AECs treated with the Rho pathway inhibitor blebbistatin. Myosin phosphatase inhibition increased MLC2 phosphorylation in stretched type I-like AECs but had no effect on monolayer permeability. In summary, stretch alters RhoA activity, ROCK activity, and MLC2 phosphorylation in a manner dependent on stretch magnitude and cell type. PMID:22287611

  16. Rho kinase signaling pathways during stretch in primary alveolar epithelia

    PubMed Central

    DiPaolo, Brian C.

    2012-01-01

    Alveolar epithelial cells (AECs) maintain integrity of the blood-gas barrier with actin-anchored intercellular tight junctions. Stretched type I-like AECs undergo magnitude- and frequency-dependent actin cytoskeletal remodeling into perijunctional actin rings. On the basis of published studies in human pulmonary artery endothelial cells (HPAECs), we hypothesize that RhoA activity, Rho kinase (ROCK) activity, and phosphorylation of myosin light chain II (MLC2) increase in stretched type I-like AECs in a manner that is dependent on stretch magnitude, and that RhoA, ROCK, or MLC2 activity inhibition will attenuate stretch-induced actin remodeling and preserve barrier properties. Primary type I-like AEC monolayers were stretched biaxially to create a change in surface area (ΔSA) of 12%, 25%, or 37% in a cyclic manner at 0.25 Hz for up to 60 min or left unstretched. Type I-like AECs were also treated with Rho pathway inhibitors (ML-7, Y-27632, or blebbistatin) and stained for F-actin or treated with the myosin phosphatase inhibitor calyculin-A and quantified for monolayer permeability. Counter to our hypothesis, ROCK activity and MLC2 phosphorylation decreased in type I-like AECs stretched to 25% and 37% ΔSA and did not change in monolayers stretched to 12% ΔSA. Furthermore, RhoA activity decreased in type I-like AECs stretched to 37% ΔSA. In contrast, MLC2 phosphorylation in HPAECs increased when HPAECs were stretched to 12% ΔSA but then decreased when they were stretched to 37% ΔSA, similar to type I-like AECs. Perijunctional actin rings were observed in unstretched type I-like AECs treated with the Rho pathway inhibitor blebbistatin. Myosin phosphatase inhibition increased MLC2 phosphorylation in stretched type I-like AECs but had no effect on monolayer permeability. In summary, stretch alters RhoA activity, ROCK activity, and MLC2 phosphorylation in a manner dependent on stretch magnitude and cell type. PMID:22287611

  17. Problem-Solving Test: The Mechanism of Transcription Termination by the Rho Factor

    ERIC Educational Resources Information Center

    Szeberenyi, Jozsef

    2012-01-01

    Transcription termination comes in two forms in "E. coli" cells. Rho-dependent termination requires the binding of a termination protein called Rho factor to the transcriptional machinery at the terminator region, whereas Rho-independent termination is achieved by conformational changes in the transcript itself. This article presents a test…

  18. Observation of e^+e^- to \\rho^+\\rho^- near \\sqrt{s}=10.58\\gev

    SciTech Connect

    Aubert, B.; Bona, M.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G.S.; Battaglia, M.; Brown, David Nathan; Cahn, R.N.; Jacobsen, R.G.; /LBL, Berkeley /UC, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Ferrara U. /Frascati /INFN, Genoa /Genoa U. /Harvard U. /Heidelberg U. /Humboldt U., Berlin /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT, LNS /McGill U. /INFN, Milan /Milan U. /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /Naples U. /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Padua U. /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /Perugia U. /INFN, Pisa /Pisa U. /Princeton U. /INFN, Rome /Rome U. /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /Turin U. /INFN, Trieste /Trieste U. /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2008-06-26

    The authors report the first observation of e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}, in a data sample of 379 fb{sup -1} collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring at center-of-mass energies near {radical}s = 10.58 GeV. The authors measure a cross section of {sigma}(e{sup +}e{sup -} {yields} {rho}{sup +}{rho}{sup -}) = 19.5 {+-} 1.6(stat) {+-} 3.2(syst) fb. Assuming production through single-photon annihilation, there are three independent helicity amplitudes. They measure the ratios of their squared moduli to be |F{sub 00}|{sup 2} : |F{sub 10}|{sup 2} : |F{sub 11}|{sup 2} = 0.51 {+-} 0.14(stat) {+-} 0.07(syst) : 0.10 {+-} 0.04(stat) {+-} 0.01(syst) : 0.04 {+-} 0.03(stat) {+-} 0.01(syst). The |F{sub 00}|{sup 2} result is inconsistent with the prediction of 1.0 made by QCD models with a significance of 3.1 standard deviations including systematic uncertainties.

  19. PDZ-RhoGEF and LARG Are Essential for Embryonic Development and Provide a Link between Thrombin and LPA Receptors and Rho Activation*

    PubMed Central

    Mikelis, Constantinos M.; Palmby, Todd R.; Simaan, May; Li, Wenling; Szabo, Roman; Lyons, Ruth; Martin, Daniel; Yagi, Hiroshi; Fukuhara, Shigetomo; Chikumi, Hiroki; Galisteo, Rebeca; Mukouyama, Yoh-suke; Bugge, Thomas H.; Gutkind, J. Silvio

    2013-01-01

    G protein-coupled receptors (GPCRs) linked to both members of the Gα12 family of heterotrimeric G proteins α subunits, Gα12 and Gα13, regulate the activation of Rho GTPases, thereby contributing to many key biological processes. Multiple Rho GEFs have been proposed to link Gα12/13 GPCRs to Rho activation, including PDZ-RhoGEF (PRG), leukemia-associated Rho GEF (LARG), p115-RhoGEF (p115), lymphoid blast crisis (Lbc), and Dbl. PRG, LARG, and p115 share the presence of a regulator of G protein signaling homology (RGS) domain. There is limited information on the biological roles of this RGS-containing family of RhoGEFs in vivo. p115-deficient mice are viable with some defects in the immune system and gastrointestinal motor dysfunctions, whereas in an initial study we showed that mice deficient for Larg are viable and resistant to salt-induced hypertension. Here, we generated knock-out mice for Prg and observed that these mice do not display any overt phenotype. However, deficiency in Prg and Larg leads to complex developmental defects and early embryonic lethality. Signaling from Gα11/q-linked GPCRs to Rho was not impaired in mouse embryonic fibroblasts defective in all three RGS-containing RhoGEFs. However, a combined lack of Prg, Larg, and p115 expression abolished signaling through Gα12/13 to Rho and thrombin-induced cell proliferation, directional migration, and nuclear signaling through JNK and p38. These findings provide evidence of an essential role for the RGS-containing RhoGEF family in signaling to Rho by Gα12/13-coupled GPCRs, which may likely play a critical role during embryonic development. PMID:23467409

  20. Vacuum fluctuation effects on the {rho}-meson mass and the one-{rho} exchange potential at finite temperature and density

    SciTech Connect

    Zhang, Yi-Jun; Gao, Song; Su, Ru-Keng Zhang, Yi-Jun Gao, Song Su, Ru-Keng

    1997-12-01

    Based on thermofield dynamics, the temperature- and density-dependent effective mass and screening mass of {rho} meson have been calculated. The effects of vacuum fluctuation corrections through effective nucleon mass are examined. We have shown that vacuum fluctuations give an important correction to the self-energy of the {rho} meson and lead to a reduction of the {rho}-meson mass in hot and dense matter. The temperature and density dependence of one-{rho}-meson exchange potential with vacuum fluctuation correction is also given. {copyright} {ital 1997} {ital The American Physical Society}

  1. Generation of a Single Chain Antibody Variable Fragment (scFv) to Sense Selectively RhoB Activation

    PubMed Central

    Chinestra, Patrick; Olichon, Aurélien; Medale-Giamarchi, Claire; Lajoie-Mazenc, Isabelle; Gence, Rémi; Inard, Cyril; Ligat, Laetitia; Faye, Jean-Charles; Favre, Gilles

    2014-01-01

    Determining the cellular level of activated form of RhoGTPases is of key importance to understand their regulatory functions in cell physiopathology. We previously reported scFvC1, that selectively bind to the GTP-bound form of RhoA, RhoB and RhoC. In this present study we generate, by molecular evolution, a new phage library to isolate scFvs displaying high affinity and selectivity to RhoA and RhoB. Using phage display affinity maturation against the GTP-locked mutant RhoAL63, we isolated scFvs against RhoA active conformation that display Kd values at the nanomolar range, which corresponded to an increase of affinity of three orders of magnitude compared to scFvC1. Although a majority of these evolved scFvs remained selective towards the active conformation of RhoA, RhoB and RhoC, we identified some scFvs that bind to RhoA and RhoC but not to RhoB activated form. Alternatively, we performed a substractive panning towards RhoB, and isolated the scFvE3 exhibiting a 10 times higher affinity for RhoB than RhoA activated forms. We showed the peculiar ability of scFvE3 to detect RhoB but not RhoA GTP-bound form in cell extracts overexpressing Guanine nucleotide Exchange Factor XPLN as well as in EGF stimulated HeLa cells. Our results demonstrated the ability of scFvs to distinguish RhoB from RhoA GTP-bound form and provide new selective tools to analyze the cell biology of RhoB GTPase regulation. PMID:25365345

  2. Implementation of Pollard Rho attack on elliptic curve cryptography over binary fields

    NASA Astrophysics Data System (ADS)

    Wienardo, Yuliawan, Fajar; Muchtadi-Alamsyah, Intan; Rahardjo, Budi

    2015-09-01

    Elliptic Curve Cryptography (ECC) is a public key cryptosystem with a security level determined by discrete logarithm problem called Elliptic Curve Discrete Logarithm Problem (ECDLP). John M. Pollard proposed an algorithm for discrete logarithm problem based on Monte Carlo method and known as Pollard Rho algorithm. The best current brute-force attack for ECC is Pollard Rho algorithm. In this research we implement modified Pollard Rho algorithm on ECC over GF (241). As the result, the runtime of Pollard Rho algorithm increases exponentially with the increase of the ECC key length. This work also presents the estimated runtime of Pollard Rho attack on ECC over longer bits.

  3. The crystal structure of the RhoA–AKAP-Lbc DH–PH domain complex

    PubMed Central

    Abdul Azeez, Kamal R.; Knapp, Stefan; Fernandes, João M. P.; Klussmann, Enno; Elkins, Jonathan M.

    2014-01-01

    The RhoGEF (Rho GTPase guanine-nucleotide-exchange factor) domain of AKAP-Lbc (A-kinase-anchoring protein-Lbc, also known as AKAP13) catalyses nucleotide exchange on RhoA and is involved in the development of cardiac hypertrophy. The RhoGEF activity of AKAP-Lbc has also been implicated in cancer. We have determined the X-ray crystal structure of the complex between RhoA–GDP and the AKAP-Lbc RhoGEF [DH (Dbl-homologous)–PH (pleckstrin homology)] domain to 2.1 Å (1 Å=0.1 nm) resolution. The structure reveals important differences compared with related RhoGEF proteins such as leukaemia-associated RhoGEF. Nucleotide-exchange assays comparing the activity of the DH–PH domain to the DH domain alone showed no role for the PH domain in nucleotide exchange, which is explained by the RhoA–AKAP-Lbc structure. Comparison with a structure of the isolated AKAP-Lbc DH domain revealed a change in conformation of the N-terminal ‘GEF switch’ region upon binding to RhoA. Isothermal titration calorimetry showed that AKAP-Lbc has only micromolar affinity for RhoA, which combined with the presence of potential binding pockets for small molecules on AKAP-Lbc, raises the possibility of targeting AKAP-Lbc with GEF inhibitors. PMID:25186459

  4. Platelet Rho GTPases–a focus on novel players, roles and relationships

    PubMed Central

    Goggs, Robert; Williams, Christopher M.; Mellor, Harry; Poole, Alastair W.

    2015-01-01

    Rho GTPases are critical for platelet function. Although the roles of RhoA, Rac and Cdc42 are characterized, platelets express other Rho GTPases, whose activities are less well understood. This review summarizes our understanding of the roles of platelet Rho GTPases and focuses particularly on the functions of Rif and RhoG. In human platelets, Rif interacts with cytoskeleton regulators including formins mDia1 and mDia3, whereas RhoG binds SNARE-complex proteins and cytoskeletal regulators ELMO and DOCK1. Knockout mouse studies suggest that Rif plays no critical functions in platelets, likely due to functional overlap with other Rho GTPases. In contrast, RhoG is essential for normal granule secretion downstream of the collagen receptor GPVI. The central defect in RhoG−/− platelets is reduced dense granule secretion, which impedes integrin activation and aggregation and limits platelet recruitment to growing thrombi under shear, translating into reduced thrombus formation in vivo. Potential avenues for future work on Rho GTPases in platelets are also highlighted, including identification of the key regulator for platelet filopodia formation and investigation of the role of the many Rho GTPase regulators in platelet function in both health and disease. PMID:25748676

  5. The function of RhoGTPases in axon ensheathment and myelination

    PubMed Central

    Feltri, M. Laura; Suter, Ueli; Relvas, João B.

    2008-01-01

    RhoGTPases are molecular switches that integrate extracellular signals to perform diverse cellular responses. This ability relies on the network of proteins regulating RhoGTPases activity and localization, and on the interaction of RhoGTPases with many different cellular effectors. Myelination is an ideal place for RhoGTPases regulation, as it is the result of fine orchestration of many stimuli from at least two cell types. Recent work has revealed that RhoGTPases are required for Schwann cells to sort, ensheath and myelinate axons. Here we will review recent advances showing the critical roles for RhoGTPases in various aspects of Schwann development and myelination, including the recent discovery of their involvement in Charcot-Marie-Tooth disease. Comparison with potential roles of RhoGTPases in central nervous system myelination will be drawn. PMID:18803320

  6. I'm coming to GEF you: Regulation of RhoGEFs during cell migration.

    PubMed

    Goicoechea, Silvia M; Awadia, Sahezeel; Garcia-Mata, Rafael

    2014-01-01

    Cell migration is a highly regulated multistep process that requires the coordinated regulation of cell adhesion, protrusion, and contraction. These processes require numerous protein-protein interactions and the activation of specific signaling pathways. The Rho family of GTPases plays a key role in virtually every aspect of the cell migration cycle. The activation of Rho GTPases is mediated by a large and diverse family of proteins; the guanine nucleotide exchange factors (RhoGEFs). GEFs work immediately upstream of Rho proteins to provide a direct link between Rho activation and cell-surface receptors for various cytokines, growth factors, adhesion molecules, and G protein-coupled receptors. The regulated targeting and activation of RhoGEFs is essential to coordinate the migratory process. In this review, we summarize the recent advances in our understanding of the role of RhoGEFs in the regulation of cell migration. PMID:25482524

  7. RhoGDI2 antagonizes ovarian carcinoma growth, invasion and metastasis

    PubMed Central

    Stevens, Ellen V; Banet, Natalie; Onesto, Cercina; Plachco, Ana; Alan, Jamie K; Nikolaishvili-Feinberg, Nana; Midkiff, Bentley R; Kuan, Pei Fen; Liu, Jinsong; Miller, C Ryan; Vigil, Dominico; Graves, Lee M

    2011-01-01

    Previous studies described functional roles for Rho GDP dissociation inhibitor 2 (RhoGDI2) in bladder, gastric and breast cancers. However, only limited expression and no functional analyses have been done for RhoGDI2 in ovarian cancer. We determined RhoGDI2 protein expression and function in ovarian cancer. First, protein gel blot analysis was performed to determine the expression levels of RhoGDI2 in ovarian cells lines. RhoGDI2 but not RhoGDI1 protein expression levels varied widely in ovarian carcinoma cell lines, with elevated levels seen in Ras-transformed ovarian epithelial cells. Next, immunohistochemistry was performed to detect RhoGDI2 expression in patient samples of ovarian cysts and ovarian cancer with known histological subtype, stage, grade and outcome. RhoGDI2 protein was significantly overexpressed in high-grade compared with low-grade ovarian cancers, correlated with histological subtype, and did not correlate with stage of ovarian cancer nor between carcinomas and benign cysts. Unexpectedly, stable suppression of RhoGDI2 protein expression in HeyA8 ovarian cancer cells increased anchorage-independent growth and Matrigel invasion in vitro and in tail-vein lung colony metastatic growth in vivo. Finally, we found that RhoGDI2 stably-associated preferentially with Rac1 and suppression of RhoGDI2 expression resulted in decreased Rac1 activity and Rac-associated JNK and p38 mitogenactivated protein kinase signaling. RhoGDI2 antagonizes the invasive and metastatic phenotype of HeyA8 ovarian cancer cells. In summary, our results suggest significant cell context differences in RhoGDI2 function in cancer cell growth. PMID:22145092

  8. RhoA GTPase regulates radiation-induced alterations in endothelial cell adhesion and migration

    SciTech Connect

    Rousseau, Matthieu; Gaugler, Marie-Helene; Rodallec, Audrey; Bonnaud, Stephanie; Paris, Francois; Corre, Isabelle

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer We explore the role of RhoA in endothelial cell response to ionizing radiation. Black-Right-Pointing-Pointer RhoA is rapidly activated by single high-dose of radiation. Black-Right-Pointing-Pointer Radiation leads to RhoA/ROCK-dependent actin cytoskeleton remodeling. Black-Right-Pointing-Pointer Radiation-induced apoptosis does not require the RhoA/ROCK pathway. Black-Right-Pointing-Pointer Radiation-induced alteration of endothelial adhesion and migration requires RhoA/ROCK. -- Abstract: Endothelial cells of the microvasculature are major target of ionizing radiation, responsible of the radiation-induced vascular early dysfunctions. Molecular signaling pathways involved in endothelial responses to ionizing radiation, despite being increasingly investigated, still need precise characterization. Small GTPase RhoA and its effector ROCK are crucial signaling molecules involved in many endothelial cellular functions. Recent studies identified implication of RhoA/ROCK in radiation-induced increase in endothelial permeability but other endothelial functions altered by radiation might also require RhoA proteins. Human microvascular endothelial cells HMEC-1, either treated with Y-27632 (inhibitor of ROCK) or invalidated for RhoA by RNA interference were exposed to 15 Gy. We showed a rapid radiation-induced activation of RhoA, leading to a deep reorganisation of actin cytoskeleton with rapid formation of stress fibers. Endothelial early apoptosis induced by ionizing radiation was not affected by Y-27632 pre-treatment or RhoA depletion. Endothelial adhesion to fibronectin and formation of focal adhesions increased in response to radiation in a RhoA/ROCK-dependent manner. Consistent with its pro-adhesive role, ionizing radiation also decreased endothelial cells migration and RhoA was required for this inhibition. These results highlight the role of RhoA GTPase in ionizing radiation-induced deregulation of essential endothelial

  9. The Interplay between the Escherichia coli Rho Guanine Nucleotide Exchange Factor Effectors and the Mammalian RhoGEF Inhibitor EspH

    PubMed Central

    Wong, Alexander R. C.; Clements, Abigail; Raymond, Benoit; Crepin, Valerie F.; Frankel, Gad

    2012-01-01

    ABSTRACT Rho GTPases are important regulators of many cellular processes. Subversion of Rho GTPases is a common infection strategy employed by many important human pathogens. Enteropathogenic Escherichia coli and enterohemorrhagic Escherichia coli (EPEC and EHEC) translocate the effector EspH, which inactivates mammalian Rho guanine exchange factors (GEFs), as well as Map, EspT, and EspM2, which, by mimicking mammalian RhoGEFs, activate Rho GTPases. In this study we found that EspH induces focal adhesion disassembly, triggers cell detachment, activates caspase-3, and induces cytotoxicity. EspH-induced cell detachment and caspase-3 activation can be offset by EspT, EspM2, and the Salmonella Cdc42/Rac1 GEF effector SopE, which remain active in the presence of EspH. EPEC and EHEC therefore use a novel strategy of controlling Rho GTPase activity by translocating one effector to inactivate mammalian RhoGEFs, replacing them with bacterial RhoGEFs. This study also expands the functional range of bacterial RhoGEFs to include cell adhesion and survival. IMPORTANCE Many human pathogens use a type III secretion system to translocate effectors that can functionally be divided into signaling, disabling, and countervirulence effectors. Among the signaling effectors are those that activate Rho GTPases, which play a central role in coordinating actin dynamics. However, many pathogens also translocate effectors with antagonistic or counteractive functions. For example, Salmonella translocates SopE and SptP, which sequentially turn Rac1 and Cdc42 on and off. In this paper, we show that enteropathogenic E. coli translocates EspH, which inactivates mammalian RhoGEFs and triggers cytotoxicity and at the same time translocates the bacterial RhoGEFs EspM2 and EspT, which are insensitive to EspH, and so neutralizes EspH-induced focal adhesion disassembly, cell detachment, and caspase-3 activation. Our data point to an intriguing infection strategy in which EPEC and EHEC override cellular

  10. Sodium ferulate lowers portal pressure in rats with secondary biliary cirrhosis through the RhoA/Rho-kinase signaling pathway: A preliminary study

    PubMed Central

    WEI, LAI; YANG, JUAN; WANG, MIN; XU, SHENG-NAN; LIANG, HUA-MIN; ZHOU, QI

    2014-01-01

    Cirrhotic rats show higher expression levels of hepatic RhoA and Rho-kinase than normal healthy rats, and the activation of this signaling pathway leads to portal hypertension. Sodium ferulate (SF) has been shown to decrease the production of geranylgeranyl pyrophosphate (GGPP), a substance essential for RhoA activation. In the present study, to investigate the effects of SF on fibrosis, portal hypertension and the RhoA/Rho-kinase pathway, hepatic cirrhosis was induced in rats by bile duct ligation. Liver function and fibrogenesis-related biochemical parameters, the hepatic hydroxyproline content, the pathological characteristics of the liver sections and the levels of hepatic α-smooth muscle actin (α-SMA; by immunohistochemistry) were analyzed to assess effects of SF on hepatic fibrosis. In addition, hepatic RhoA, Rho-kinase and endothelial nitric oxide synthase (eNOS) expression was examined by immunohistochemistry. Apoptosis in the SF-treated and SF + GGPP-treated rat primary hepatic stellate cells (HSCs) and a human stellate cell line (LX-2) was examined by flow cytometry. Intrahepatic resistance and responsiveness to the α1-adrenoceptor agonist, methoxamine, were investigated by in situ liver perfusion. Treatment with SF did not affect fibrosis-related biochemical parameters or the hydroxyproline content; however, SF reduced the histological evidence of fibrosis and hepatocyte damage. The SF-treated rats had a significantly lower expression of α-SMA and Rho-kinase, as well as an increased hepatic eNOS content; however, SF did not affect RhoA expression. The SF-treated HSCs had a significantly increased apoptotic rate compared to the untreated rats. Following the addition of GGPP, the rate apoptotic rate decreased. SF reduced basal intrahepatic resistance and the responsiveness of hepatic vascular smooth muscle to methoxamine. Therefore, our data demonstrate that SF reduces fibrogenesis, decreases portal pressure in cirrhotic rats and inhibits the

  11. Color transparency in incoherent electroproduction of {rho} mesons off nuclei

    SciTech Connect

    Nemchik, J.; Kopeliovich, B. Z.; Potashnikova, I. K.

    2013-04-15

    Color transparency (CT) phenomena in elastic electroproduction of vector mesons off nuclei are usually infected by the onset of coherence length (CL) effects. However, at low energies corresponding to the CLAS experiment at Jefferson Lab (JLab), one can study practically the net CT effects, since CL is much shorter than the nuclear radius. We investigate various manifestations of CT effects using rigorous quantum mechanical approach based on the path integral technique. We include also the effects of {rho} meson decay inside the nucleus leading to a rise of the nuclear suppression towards small values of Q{sup 2}. Motivated by the last CLAS data we predict the A, Q{sup 2} and l{sub c} dependence of nuclear transparency for {rho}{sup 0} mesons produced incoherently off nuclei. We also perform predictions for expected signal of CT corresponding to the planned JLab upgrade to 12 GeV electron beam.

  12. Modelling Rho GTPase biochemistry to predict collective cell migration

    NASA Astrophysics Data System (ADS)

    Merchant, Brian; Feng, James

    The collective migration of cells, due to individual cell polarization and intercellular contact inhibition of locomotion, features prominently in embryogenesis and metastatic cancers. Existing methods for modelling collectively migrating cells tend to rely either on highly abstracted agent-based models, or on continuum approximations of the group. Both of these frameworks represent intercellular interactions such as contact inhibition of locomotion as hard-coded rules defining model cells. In contrast, we present a vertex-dynamics framework which predicts polarization and contact inhibition of locomotion naturally from an underlying model of Rho GTPase biochemistry and cortical mechanics. We simulate the interaction between many such model cells, and study how modulating Rho GTPases affects migratory characteristics of the group, in the context of long-distance collective migration of neural crest cells during embryogenesis.

  13. Resonance Parameters of the Rho-Meson from Lattice QCD

    SciTech Connect

    Xu Feng, Karl Jansen, Dru Renner

    2011-05-01

    We perform a non-perturbative lattice calculation of the P-wave pion-pion scattering phase in the rho-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 MeV to 290 MeV. Making use of finite-size methods, we evaluate the pion-pion scattering phase in the center-of-mass frame and two moving frames. Applying an effective range formula, we find a good description of our results for the scattering phase as a function of the energy covering the resonance region. This allows us to extract the rho-meson mass and decay width and to study their quark mass dependence.

  14. Resonance parameters of the {rho} meson from lattice QCD

    SciTech Connect

    Feng Xu; Jansen, Karl; Renner, Dru B.

    2011-05-01

    We perform a nonperturbative lattice calculation of the P-wave pion-pion scattering phase in the {rho}-meson decay channel using two flavors of maximally twisted mass fermions at pion masses ranging from 480 to 290 MeV. Making use of finite-size methods, we evaluate the pion-pion scattering phase in the center-of-mass frame and two moving frames. Applying an effective range formula, we find a good description of our results for the scattering phase as a function of the energy covering the resonance region. This allows us to extract the {rho}-meson mass and decay width and to study their quark mass dependence.

  15. Involvement of Rho-kinase in experimental vascular endothelial dysfunction.

    PubMed

    Shah, Dhvanit I; Singh, Manjeet

    2006-02-01

    The present study has been designed to investigate the effect of fasudil (Rho-kinase inhibitor) in diabetes mellitus (DM) and hyperhomocyteinemia (HHcy) induced vascular endothelial dysfunction (VED). Streptozotocin (55 mg kg(-1), i.v., once only) and methionine (1.7% w/w, p.o., daily for 4 weeks) were administered to rats to produce DM (serum glucose >140 mg dl(-1)) and HHcy (serum homocysteine >10 microM) respectively. VED was assessed using isolated aortic ring, electron microscopy of thoracic aorta, and serum concentration of nitrite/nitrate. Serum thiobarbituric acid reactive substances (TBARS) concentration was estimated to assess oxidative stress. Atorvastatin has been employed in the present study as standard agent to improve vascular endothelial dysfunction. Fasudil (15 mg kg(-1) and 30 mg kg(-1), p.o., daily) and atorvastatin (30 mg kg(-1), p.o., daily) treatments significantly attenuated increase in serum glucose and homocysteine but their concentrations remained markedly higher than sham control value. Fasudil and atorvastatin treatments markedly prevented DM and HHcy-induced (i) attenuation of acetylcholine induced endothelium-dependent relaxation, (ii) impairment of vascular endothelial lining, (iii) decrease in serum nitrite/nitrate concentration, and (iv) increase in serum TBARS. It may be concluded that fasudil prevented DM and HHcy-induced VED partially by decreasing serum glucose and homocysteine concentration due to inhibition of Rho-kinase. Moreover, inhibition of Rho-kinase by fasudil and consequent prevention of oxidative stress may have directly improved VED in diabetic and hyperhomocysteinemic rats. The Rho-kinase appears to be a pivotal target site involved in DM and HHcy-induced VED. PMID:16444602

  16. Necessary conditions for the mapping of. gamma. into rho

    SciTech Connect

    Ludea, E.V.; Sierraalta, A.

    1985-07-01

    We have obtained necessary conditions for the mapping of the reduced first-order density operator ..gamma.. into the density rho. These conditions are given as restrictions on the elements of GAMMA, the reduced first-order density matrix. The implications of these conditions for a density-functional theory based on ..gamma.., with built-in pure-state n-representability conditions, are discussed.

  17. Targeting Rho-GTPases in immune cell migration and inflammation

    PubMed Central

    Biro, Maté; Munoz, Marcia A; Weninger, Wolfgang

    2014-01-01

    Leukocytes are unmatched migrators capable of traversing barriers and tissues of remarkably varied structural composition. An effective immune response relies on the ability of its constituent cells to infiltrate target sites. Yet, unwarranted mobilization of immune cells can lead to inflammatory diseases and tissue damage ranging in severity from mild to life-threatening. The efficacy and plasticity of leukocyte migration is driven by the precise spatiotemporal regulation of the actin cytoskeleton. The small GTPases of the Rho family (Rho-GTPases), and their immediate downstream effector kinases, are key regulators of cellular actomyosin dynamics and are therefore considered prime pharmacological targets for stemming leukocyte motility in inflammatory disorders. This review describes advances in the development of small-molecule inhibitors aimed at modulating the Rho-GTPase-centric regulatory pathways governing motility, many of which stem from studies of cancer invasiveness. These inhibitors promise the advent of novel treatment options with high selectivity and potency against immune-mediated pathologies. Linked Articles This article is part of a themed section on Cytoskeleton, Extracellular Matrix, Cell Migration, Wound Healing and Related Topics. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue-24 PMID:24571448

  18. Salidroside ameliorates arthritis-induced brain cognition deficits by regulating Rho/ROCK/NF-κB pathway.

    PubMed

    Zhu, Lingpeng; Chen, Tong; Chang, Xiayun; Zhou, Rui; Luo, Fen; Liu, Jingyan; Zhang, Kai; Wang, Yue; Yang, Ying; Long, Hongyan; Liu, Yu; Yan, Tianhua; Ma, Chunhua

    2016-04-01

    The prevalence of cognitive impairment in rheumatoid arthritis (RA) patients was increasingly serious nowadays. The purpose of the current study was to explore whether salidroside (Sal) could alleviate arthritis-induced cognition deficits and examine the relationship between the impairment and Rho/ROCK/NF-κB pathway. Collagen-induced arthritis (CIA) was established by the injection of chicken type II collagen (CII), complete Freund's adjuvant (CFA) and incomplete Freund's adjuvant (IFA). Arthritic lesions of CIA rats were assessed by arthritis index score, swelling of paws and histological analysis. Cognitive deficits symptoms of CIA rats were monitored through Morris water maze test. The contents of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in hippocampus and serum were significantly reduced with salidroside (20 mg/kg, 40 mg/kg) treatment compared with those in the CIA group. In parallel, we demonstrated that the expressions of RhoA, ROCK1, ROCK2, p-NF-κBp65, p-IκBα, p-IKKα and p-IKKβ were enhanced accompanying the investigation arthritis-induced cognition deficits, which were remarkably down-regulated by salidroside and confirmed by the results obtained from western blot and immunohistochemistry. LC-MS/MS results ascertained that Sal could enter into the blood and brain tissues to exhibit the protective effect on arthritis-induced cognitive dysfunction. Therefore, it was assumed that Sal might be a potential therapeutic candidate to treat arthritis-induced brain cognition deficits through the regulation of Rho/ROCK/NF-κB signaling. PMID:26690894

  19. Alteration of Pituitary Tumor Transforming Gene-1 Regulates Trophoblast Invasion via the Integrin/Rho-Family Signaling Pathway

    PubMed Central

    Lim, Seung Mook; Jang, Hee Yeon; Lee, Ji Eun; Shin, Joong Sik; Park, Sun-Hwa; Yoon, Bo Hyun; Kim, Gi Jin

    2016-01-01

    Trophoblast invasion ability is an important factor in early implantation and placental development. Recently, pituitary tumor transforming gene 1 (PTTG1) was shown to be involved in invasion and proliferation of cancer. However, the role of PTTG1 in trophoblast invasion remains unknown. Thus, in this study we analyzed PTTG1 expression in trophoblasts and its effect on trophoblast invasion activity and determined the mechanism through which PTTG1 regulates trophoblast invasion. Trophoblast proliferation and invasion abilities, regardless of PTTG1 expression, were analyzed by quantitative real-time polymerase chain reaction, fluorescence-activated cell sorting analysis, invasion assay, western blot, and zymography after treatment with small interfering RNA against PTTG1 (siPTTG1). Additionally, integrin/Rho-family signaling in trophoblasts by PTTG1 alteration was analyzed. Furthermore, the effect of PTTG1 on trophoblast invasion was evaluated by microRNA (miRNA) mimic and inhibitor treatment. Trophoblast invasion was significantly reduced through decreased matrix metalloproteinase (MMP)-2 and MMP-9 expression when PTTG1 expression was inhibited by siPTTG1 (p < 0.05). Furthermore, knockdown of PTTG1 increased expression of integrin alpha 4 (ITGA4), ITGA5, and integrin beta 1 (ITGB1); otherwise, RhoA expression was significantly decreased (p < 0.05). Treatment of miRNA-186-5p mimic and inhibitor controlled trophoblast invasion ability by altering PTTG1 and MMP expression. PTTG1 can control trophoblast invasion ability via regulation of MMP expression through integrin/Rho-family signaling. In addition, PTTG1 expression and its function were regulated by miRNA-186-5p. These results help in understanding the mechanism through which PTTG1 regulates trophoblast invasion and thereby implantation and placental development. PMID:26900962

  20. The Rho-guanine nucleotide exchange factor PDZ-RhoGEF governs susceptibility to diet-induced obesity and type 2 diabetes

    PubMed Central

    Chang, Ying-Ju; Pownall, Scott; Jensen, Thomas E; Mouaaz, Samar; Foltz, Warren; Zhou, Lily; Liadis, Nicole; Woo, Minna; Hao, Zhenyue; Dutt, Previn; Bilan, Philip J; Klip, Amira; Mak, Tak; Stambolic, Vuk

    2015-01-01

    Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide exchange factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-induced obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies. DOI: http://dx.doi.org/10.7554/eLife.06011.001 PMID:26512886

  1. The Rho-guanine nucleotide exchange factor PDZ-RhoGEF governs susceptibility to diet-induced obesity and type 2 diabetes.

    PubMed

    Chang, Ying-Ju; Pownall, Scott; Jensen, Thomas E; Mouaaz, Samar; Foltz, Warren; Zhou, Lily; Liadis, Nicole; Woo, Minna; Hao, Zhenyue; Dutt, Previn; Bilan, Philip J; Klip, Amira; Mak, Tak; Stambolic, Vuk

    2015-01-01

    Adipose tissue is crucial for the maintenance of energy and metabolic homeostasis and its deregulation can lead to obesity and type II diabetes (T2D). Using gene disruption in the mouse, we discovered a function for a RhoA-specific guanine nucleotide exchange factor PDZ-RhoGEF (Arhgef11) in white adipose tissue biology. While PDZ-RhoGEF was dispensable for a number of RhoA signaling-mediated processes in mouse embryonic fibroblasts, including stress fiber formation and cell migration, it's deletion led to a reduction in their proliferative potential. On a whole organism level, PDZ-RhoGEF deletion resulted in an acute increase in energy expenditure, selectively impaired early adipose tissue development and decreased adiposity in adults. PDZ-RhoGEF-deficient mice were protected from diet-induced obesity and T2D. Mechanistically, PDZ-RhoGEF enhanced insulin/IGF-1 signaling in adipose tissue by controlling ROCK-dependent phosphorylation of the insulin receptor substrate-1 (IRS-1). Our results demonstrate that PDZ-RhoGEF acts as a key determinant of mammalian metabolism and obesity-associated pathologies. PMID:26512886

  2. Rho family GTPases: key players in neuronal development, neuronal survival, and neurodegeneration

    PubMed Central

    Stankiewicz, Trisha R.; Linseman, Daniel A.

    2014-01-01

    The Rho family of GTPases belongs to the Ras superfamily of low molecular weight (∼21 kDa) guanine nucleotide binding proteins. The most extensively studied members are RhoA, Rac1, and Cdc42. In the last few decades, studies have demonstrated that Rho family GTPases are important regulatory molecules that link surface receptors to the organization of the actin and microtubule cytoskeletons. Indeed, Rho GTPases mediate many diverse critical cellular processes, such as gene transcription, cell–cell adhesion, and cell cycle progression. However, Rho GTPases also play an essential role in regulating neuronal morphology. In particular, Rho GTPases regulate dendritic arborization, spine morphogenesis, growth cone development, and axon guidance. In addition, more recent efforts have underscored an important function for Rho GTPases in regulating neuronal survival and death. Interestingly, Rho GTPases can exert either a pro-survival or pro-death signal in neurons depending upon both the cell type and neurotoxic insult involved. This review summarizes key findings delineating the involvement of Rho GTPases and their effectors in the regulation of neuronal survival and death. Collectively, these results suggest that dysregulation of Rho family GTPases may potentially underscore the etiology of some forms of neurodegenerative disease such as amyotrophic lateral sclerosis. PMID:25339865

  3. Rho family GTPases: key players in neuronal development, neuronal survival, and neurodegeneration.

    PubMed

    Stankiewicz, Trisha R; Linseman, Daniel A

    2014-01-01

    The Rho family of GTPases belongs to the Ras superfamily of low molecular weight (∼21 kDa) guanine nucleotide binding proteins. The most extensively studied members are RhoA, Rac1, and Cdc42. In the last few decades, studies have demonstrated that Rho family GTPases are important regulatory molecules that link surface receptors to the organization of the actin and microtubule cytoskeletons. Indeed, Rho GTPases mediate many diverse critical cellular processes, such as gene transcription, cell-cell adhesion, and cell cycle progression. However, Rho GTPases also play an essential role in regulating neuronal morphology. In particular, Rho GTPases regulate dendritic arborization, spine morphogenesis, growth cone development, and axon guidance. In addition, more recent efforts have underscored an important function for Rho GTPases in regulating neuronal survival and death. Interestingly, Rho GTPases can exert either a pro-survival or pro-death signal in neurons depending upon both the cell type and neurotoxic insult involved. This review summarizes key findings delineating the involvement of Rho GTPases and their effectors in the regulation of neuronal survival and death. Collectively, these results suggest that dysregulation of Rho family GTPases may potentially underscore the etiology of some forms of neurodegenerative disease such as amyotrophic lateral sclerosis. PMID:25339865

  4. Axon growth inhibition by RhoA/ROCK in the central nervous system

    PubMed Central

    Fujita, Yuki; Yamashita, Toshihide

    2014-01-01

    Rho kinase (ROCK) is a serine/threonine kinase and a downstream target of the small GTPase Rho. The RhoA/ROCK pathway is associated with various neuronal functions such as migration, dendrite development, and axonal extension. Evidence from animal studies reveals that RhoA/ROCK signaling is involved in various central nervous system (CNS) diseases, including optic nerve and spinal cord injuries, stroke, and neurodegenerative diseases. Given that RhoA/ROCK plays a critical role in the pathophysiology of CNS diseases, the development of therapeutic agents targeting this pathway is expected to contribute to the treatment of CNS diseases. The RhoA/ROCK pathway mediates the effects of myelin-associated axon growth inhibitors—Nogo, myelin-associated glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), and repulsive guidance molecule (RGM). Blocking RhoA/ROCK signaling can reverse the inhibitory effects of these molecules on axon outgrowth, and promotes axonal sprouting and functional recovery in animal models of CNS injury. To date, several RhoA/ROCK inhibitors have been under development or in clinical trials as therapeutic agents for neurological disorders. In this review, we focus on the RhoA/ROCK signaling pathway in neurological disorders. We also discuss the potential therapeutic approaches of RhoA/ROCK inhibitors for various neurological disorders. PMID:25374504

  5. Rho GTPase and Shroom direct planar polarized actomyosin contractility during convergent extension.

    PubMed

    Simões, Sérgio de Matos; Mainieri, Avantika; Zallen, Jennifer A

    2014-02-17

    Actomyosin contraction generates mechanical forces that influence cell and tissue structure. During convergent extension in Drosophila melanogaster, the spatially regulated activity of the myosin activator Rho-kinase promotes actomyosin contraction at specific planar cell boundaries to produce polarized cell rearrangement. The mechanisms that direct localized Rho-kinase activity are not well understood. We show that Rho GTPase recruits Rho-kinase to adherens junctions and is required for Rho-kinase planar polarity. Shroom, an asymmetrically localized actin- and Rho-kinase-binding protein, amplifies Rho-kinase and myosin II planar polarity and junctional localization downstream of Rho signaling. In Shroom mutants, Rho-kinase and myosin II achieve reduced levels of planar polarity, resulting in decreased junctional tension, a disruption of multicellular rosette formation, and defective convergent extension. These results indicate that Rho GTPase activity is required to establish a planar polarized actomyosin network, and the Shroom actin-binding protein enhances myosin contractility locally to generate robust mechanical forces during axis elongation. PMID:24535826

  6. ATP-dependent motor activity of the transcription termination factor Rho from Mycobacterium tuberculosis

    PubMed Central

    D'Heygère, François; Schwartz, Annie; Coste, Franck; Castaing, Bertrand; Boudvillain, Marc

    2015-01-01

    The bacterial transcription termination factor Rho—a ring-shaped molecular motor displaying directional, ATP-dependent RNA helicase/translocase activity—is an interesting therapeutic target. Recently, Rho from Mycobacterium tuberculosis (MtbRho) has been proposed to operate by a mechanism uncoupled from molecular motor action, suggesting that the manner used by Rho to dissociate transcriptional complexes is not conserved throughout the bacterial kingdom. Here, however, we demonstrate that MtbRho is a bona fide molecular motor and directional helicase which requires a catalytic site competent for ATP hydrolysis to disrupt RNA duplexes or transcription elongation complexes. Moreover, we show that idiosyncratic features of the MtbRho enzyme are conferred by a large, hydrophilic insertion in its N-terminal ‘RNA binding’ domain and by a non-canonical R-loop residue in its C-terminal ‘motor’ domain. We also show that the ‘motor’ domain of MtbRho has a low apparent affinity for the Rho inhibitor bicyclomycin, thereby contributing to explain why M. tuberculosis is resistant to this drug. Overall, our findings support that, in spite of adjustments of the Rho motor to specific traits of its hosting bacterium, the basic principles of Rho action are conserved across species and could thus constitute pertinent screening criteria in high-throughput searches of new Rho inhibitors. PMID:25999346

  7. RhoB controls endothelial barrier recovery by inhibiting Rac1 trafficking to the cell border.

    PubMed

    Marcos-Ramiro, Beatriz; García-Weber, Diego; Barroso, Susana; Feito, Jorge; Ortega, María C; Cernuda-Morollón, Eva; Reglero-Real, Natalia; Fernández-Martín, Laura; Durán, Maria C; Alonso, Miguel A; Correas, Isabel; Cox, Susan; Ridley, Anne J; Millán, Jaime

    2016-05-01

    Endothelial barrier dysfunction underlies chronic inflammatory diseases. In searching for new proteins essential to the human endothelial inflammatory response, we have found that the endosomal GTPase RhoB is up-regulated in response to inflammatory cytokines and expressed in the endothelium of some chronically inflamed tissues. We show that although RhoB and the related RhoA and RhoC play additive and redundant roles in various aspects of endothelial barrier function, RhoB specifically inhibits barrier restoration after acute cell contraction by preventing plasma membrane extension. During barrier restoration, RhoB trafficking is induced between vesicles containing RhoB nanoclusters and plasma membrane protrusions. The Rho GTPase Rac1 controls membrane spreading and stabilizes endothelial barriers. We show that RhoB colocalizes with Rac1 in endosomes and inhibits Rac1 activity and trafficking to the cell border during barrier recovery. Inhibition of endosomal trafficking impairs barrier reformation, whereas induction of Rac1 translocation to the plasma membrane accelerates it. Therefore, RhoB-specific regulation of Rac1 trafficking controls endothelial barrier integrity during inflammation. PMID:27138256

  8. Diagnosing fuel {rho}R and {rho}R asymmetries in cryogenic deuterium-tritium implosions using charged-particle spectrometry at OMEGA

    SciTech Connect

    Frenje, J. A.; Li, C. K.; Seguin, F. H.; Casey, D. T.; Petrasso, R. D.; Sangster, T. C.; Betti, R.; Glebov, V. Yu.; Meyerhofer, D. D.

    2009-04-15

    Determining fuel areal density ({rho}R) in moderate-{rho}R (100-200 mg/cm{sup 2}) cryogenic deuterium-tritium (DT) implosions is challenging as it requires new spectrometry techniques and analysis methods to be developed. In this paper, we describe a new method for analyzing the spectrum of knock-on deuterons (KO-Ds), elastically scattered by primary DT neutrons, from which a fuel {rho}R can be inferred for values up to {approx}200 mg/cm{sup 2}. This new analysis method, which uses Monte Carlo modeling of a cryogenic DT implosion, improves significantly the previous analysis method in two fundamental ways. First, it is not affected by significant spatial-yield variations, which degrade the diagnosis of the fuel {rho}R (spatial yield variations of about {+-}20% are typically observed), and second, it does not break down when the fuel {rho}R exceeds {approx}70 mg/cm{sup 2}.

  9. Localized RhoA GTPase activity regulates dynamics of endothelial monolayer integrity

    PubMed Central

    Szulcek, Robert; Beckers, Cora M.L.; Hodzic, Jasmina; de Wit, Jelle; Chen, Zhenlong; Grob, Tim; Musters, Rene J.P.; Minshall, Richard D.; van Hinsbergh, Victor W.M.; van Nieuw Amerongen, Geerten P.

    2013-01-01

    Aims Endothelial cells (ECs) control vascular permeability by forming a monolayer that is sealed by extracellular junctions. Various mediators modulate the endothelial barrier by acting on junctional protein complexes and the therewith connected F-actin cytoskeleton. Different Rho GTPases participate in this modulation, but their mechanisms are still partly resolved. Here, we aimed to elucidate whether the opening and closure of the endothelial barrier are associated with distinct localized RhoA activities at the subcellular level. Methods and results Live fluorescence resonance energy transfer (FRET) microscopy revealed spatially distinct RhoA activities associated with different aspects of the regulation of endothelial monolayer integrity. Unstimulated ECs were characterized by hotspots of RhoA activity at their periphery. Thrombin receptor activation in the femoral vein of male wistar rats and in cultured ECs enhanced RhoA activity at membrane protrusions, followed by a more sustained RhoA activity associated with cytoplasmic F-actin filaments, where prolonged RhoA activity coincided with cellular contractility. Unexpectedly, thrombin-induced peripheral RhoA hotspots were not spatially correlated to the formation of large inter-endothelial gaps. Rather, spontaneous RhoA activity at membrane protrusions coincided with the closure of inter-endothelial gaps. Electrical impedance measurements showed that RhoA signalling is essential for this protrusive activity and maintenance of barrier restoration. Conclusion Spontaneous RhoA activity at membrane protrusions is spatially associated with closure, but not formation of inter-endothelial gaps, whereas RhoA activity at distant contractile filaments contributes to thrombin-induced disruption of junctional integrity. Thus, these data indicate that distinct RhoA activities are associated with disruption and re-annealing of endothelial junctions. PMID:23536606

  10. Characterization and expression of the human rhoH12 gene product

    SciTech Connect

    Avraham, H.; Weinberg, R.A.

    1989-05-01

    The rho genes constitute an evolutionarily conserved family having significant homology to the ras oncogene family. These genes have been found in Saccharomyces cerevisiae, Drosophila melanogaster, rat, and human; their 21,000-dalton products show strong conservation of structure. In humans, three classes of rho cDNA clones have been identified which differ by virtue of the presence of variable C-terminal domains: rhoH12, rhoH6, and rhoH9. The predicted 193 amino acids of human rhoH12 protein show 88% similarity with those of the human rhoH6 clone, 96.8% similarity with those of the Aplysia rho product, and 81.8% similarity with those of the yeast RHO1 protein. Rat-1 and NIH 3T3 mouse fibroblasts were transfected with clones containing the normal human rhoH12 allele as well as the variants encoding valine in the place of the glycine and leucine in place of the gutamine normally found at residues 14 and 64, respectively. These replacements mirror the changes responsible for oncogenic activation of the related ras-encoded p21 proteins. These mutant rhoH12 clone alleles did not cause focus formation in monolayers or growth in soft agar. However, amplification of normal rhoH12 via contransfection with a dihydrofolate reductase gene resulted in colonies that displayed reduced dependence on serum for growth, grew to higher saturation densities, and were tumorigenic when inoculated into nude mice. Normal p21rho proteins was detected in the transfected cell lines as well as in normal cell lines by Western immunoblot and immunoprecipitation analysis with rabbit antibodies raised against the peptide corresponding to amino acids 122 to 135.

  11. Signaling Pathways That Control Rho Kinase Activity Maintain the Embryonic Epicardial Progenitor State

    PubMed Central

    Artamonov, Mykhaylo V.; Jin, Li; Franke, Aaron S.; Momotani, Ko; Ho, Ruoya; Dong, Xiu Rong; Majesky, Mark W.; Somlyo, Avril V.

    2015-01-01

    This study identifies signaling pathways that play key roles in the formation and maintenance of epicardial cells, a source of progenitors for coronary smooth muscle cells (SMCs). After epithelial to mesenchymal transition (EMT), mesenchymal cells invade the myocardium to form coronary SMCs. RhoA/Rho kinase activity is required for EMT and for differentiation into coronary SMCs, whereas cAMP activity is known to inhibit EMT in epithelial cells by an unknown mechanism. We use outgrowth of epicardial cells from E9.5 isolated mouse proepicardium (PE) explants, wild type and Epac1 null E12.5 mouse heart explants, adult rat epicardial cells, and immortalized mouse embryonic epicardial cells as model systems to identify signaling pathways that regulate RhoA activity to maintain the epicardial progenitor state. We demonstrate that RhoA activity is suppressed in the epicardial progenitor state, that the cAMP-dependent Rap1 GTP exchange factor (GEF), Epac, known to down-regulate RhoA activity through activation of Rap1 GTPase activity increased, that Rap1 activity increased, and that expression of the RhoA antagonistic Rnd proteins known to activate p190RhoGAP increased and associated with p190RhoGAP. Finally, EMT is associated with increased p63RhoGEF and RhoGEF-H1 protein expression, increased GEF-H1 activity, with a trend in increased p63RhoGEF activity. EMT is suppressed by partial silencing of p63RhoGEF and GEF-H1. In conclusion, we have identified new signaling molecules that act together to control RhoA activity and play critical roles in the maintenance of coronary smooth muscle progenitor cells in the embryonic epicardium. We suggest that their eventual manipulation could promote revascularization after myocardial injury. PMID:25733666

  12. Yeast RNC1 encodes a chimeric protein, RhoNUC, with a human rho motif and deoxyribonuclease activity.

    PubMed Central

    Chow, T Y; Perkins, E L; Resnick, M A

    1992-01-01

    The yeast Saccharomyces cerevisiae contains an endoexonuclease yNucR that has been implicated in both recombination and repair. We describe the isolation and characterization of the corresponding gene. Within the predicted N-terminal half of the protein there is extensive homology (approximately 50%) with human rho genes, which are related to the ras oncogene, particularly in the proposed GTP-binding region. The C-terminal region, which is related to the Escherichia coli recC protein, presumably encodes the endoexonuclease activity. The yNucR may thus represent a new class of GTP-binding proteins. Because of the chimeric nature of the polypeptide, this protein is renamed RhoNUC (rather than the original yNucR) and the gene is RNC1 for Rho-associated-NuClease. Over expression of the gene leads to altered cell growth and nuclear morphology. We propose that the gene plays an important role in cell development as well as DNA repair/recombination. Images PMID:1408836

  13. RhoA/rho kinase signaling reduces connexin43 expression in high glucose-treated glomerular mesangial cells with zonula occludens-1 involvement

    SciTech Connect

    Xie, Xi; Chen, Cheng; Huang, Kaipeng; Wang, Shaogui; Hao, Jie; Huang, Junying; Huang, Heqing

    2014-10-01

    RhoA/Rho kinase (ROCK) signaling has been suggested to be involved in diabetic nephropathy (DN) pathogenesis. Altered expression of connexin43 (Cx43) has been found in kidneys of diabetic animals. Both of them have been found to regulate nuclear factor kappa-B (NF-κB) activation in high glucose-treated glomerular mesangial cells (GMCs). The aim of this study was to investigate the relationship between RhoA/ROCK signaling and Cx43 in the DN pathogenesis. We found that upregulation of Cx43 expression inhibited NF-κB p65 nuclear translocation induced by RhoA/ROCK signaling in GMCs. Inhibition of RhoA/ROCK signaling attenuated the high glucose-induced decrease in Cx43. F-actin accumulation and an enhanced interaction between zonula occludens-1 (ZO-1) and Cx43 were observed in high glucose-treated GMCs. ZO-1 depletion or disruption of F-actin formation also inhibited the reduction in Cx43 protein levels induced by high glucose. In conclusion, activated RhoA/ROCK signaling induces Cx43 degradation in GMCs cultured in high glucose, depending on F-actin regulation. Increased F-actin induced by RhoA/ROCK signaling promotes the association between ZO-1 and Cx43, which possibly triggered Cx43 endocytosis, a mechanism of NF-κB activation in high glucose-treated GMCs. - Highlights: • RhoA/ROCK signaling induces Cx43 degradation in GMCs. • F-actin and ZO-1 have functions in the regulation of Cx43 by RhoA/ROCK signaling. • We reveal the relationship between RhoA/ROCK and Cx43 in the activation of NF-κB.

  14. Alpha(phi2) From a Time-Dependent Analysis of B0 -> (rhopi)0 Dalitz-plot

    SciTech Connect

    Mohanty, G; U., Warwick

    2008-10-13

    The authors present results of time-dependent Dalitz plot analyses of B{sup 0} {yields} ({rho}{pi}){sup 0} and the corresponding constraints on the angle {alpha} or {phi}{sub 2} of the CKM unitarity triangle from the B factories.

  15. The dynamics of spatio-temporal Rho GTPase signaling: formation of signaling patterns

    PubMed Central

    Fritz, Rafael Dominik; Pertz, Olivier

    2016-01-01

    Rho GTPases are crucial signaling molecules that regulate a plethora of biological functions. Traditional biochemical, cell biological, and genetic approaches have founded the basis of Rho GTPase biology. The development of biosensors then allowed measuring Rho GTPase activity with unprecedented spatio-temporal resolution. This revealed that Rho GTPase activity fluctuates on time and length scales of tens of seconds and micrometers, respectively. In this review, we describe Rho GTPase activity patterns observed in different cell systems. We then discuss the growing body of evidence that upstream regulators such as guanine nucleotide exchange factors and GTPase-activating proteins shape these patterns by precisely controlling the spatio-temporal flux of Rho GTPase activity. Finally, we comment on additional mechanisms that might feed into the regulation of these signaling patterns and on novel technologies required to dissect this spatio-temporal complexity. PMID:27158467

  16. Rho-associated protein kinase modulates neurite extension by regulating microtubule remodeling and vinculin distribution

    PubMed Central

    Chen, Ke’en; Zhang, Wenbin; Chen, Jing; Li, Sumei; Guo, Guoqing

    2013-01-01

    Rho-associated protein kinase is an essential regulator of cytoskeletal dynamics during the process of neurite extension. However, whether Rho kinase regulates microtubule remodeling or the distribution of adhesive proteins to mediate neurite outgrowth remains unclear. By specifically modulating Rho kinase activity with pharmacological agents, we studied the morpho-dynamics of neurite outgrowth. We found that lysophosphatidic acid, an activator of Rho kinase, inhibited neurite outgrowth, which could be reversed by Y-27632, an inhibitor of Rho kinase. Meanwhile, reorganization of microtubules was noticed during these processes, as indicated by their significant changes in the soma and growth cone. In addition, exposure to lysophosphatidic acid led to a decreased membrane distribution of vinculin, a focal adhesion protein in neurons, whereas Y-27632 recruited vinculin to the membrane. Taken together, our data suggest that Rho kinase regulates rat hippocampal neurite growth and microtubule formation via a mechanism associated with the redistribution of vinculin. PMID:25206623

  17. Alpha-1 Antitrypsin Deficiency

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Alpha-1 Antitrypsin Deficiency? Alpha-1 antitrypsin (an-tee-TRIP-sin) deficiency, or AAT ... as it relates to lung disease. Overview Alpha-1 antitrypsin, also called AAT, is a protein made ...

  18. Rho GTPases have diverse effects on the organization of the actin filament system.

    PubMed Central

    Aspenström, Pontus; Fransson, Asa; Saras, Jan

    2004-01-01

    The Rho GTPases are related to the Ras proto-oncogenes and consist of 22 family members. These proteins have important roles in regulating the organization of the actin filament system, and thereby the morphogenesis of vertebrate cells as well as their ability to migrate. In an effort to compare the effects of all members of the Rho GTPase family, active Rho GTPases were transfected into porcine aortic endothelial cells and the effects on the actin filament system were monitored. Cdc42, TCL (TC10-like), Rac1-Rac3 and RhoG induced the formation of lamellipodia, whereas Cdc42, Rac1 and Rac2 also induced the formation of thick bundles of actin filaments. In contrast, transfection with TC10 or Chp resulted in the formation of focal adhesion-like structures, whereas Wrch-1 induced long and thin filopodia. Transfection with RhoA, RhoB or RhoC induced the assembly of stress fibres, whereas Rnd1-Rnd3 resulted in the loss of stress fibres, but this effect was associated with the formation of actin- and ezrin-containing dorsal microvilli. Cells expressing RhoD and Rif had extremely long and flexible filopodia. None of the RhoBTB or Miro GTPases had any major influence on the organization of the actin filament system; instead, RhoBTB1 and RhoBTB2 were present in vesicular structures, and Miro-1 and Miro-2 were present in mitochondria. Collectively, the data obtained in this study to some extent confirm earlier observations, but also allow the identification of previously undetected roles of the different members of the Rho GTPases. PMID:14521508

  19. Overactivation of the protein kinase C-signaling pathway suppresses the defects of cells lacking the Rho3/Rho4-GAP Rgd1p in Saccharomyces cerevisiae.

    PubMed Central

    de Bettignies, G; Thoraval, D; Morel, C; Peypouquet, M F; Crouzet, M

    2001-01-01

    The nonessential RGD1 gene encodes a Rho-GTPase activating protein for the Rho3 and Rho4 proteins in Saccharomyces cerevisiae. Previous studies have revealed genetic interactions between RGD1 and the SLG1 and MID2 genes, encoding two putative sensors for cell integrity signaling, and VRP1 encoding an actin and myosin interacting protein involved in polarized growth. To better understand the role of Rgd1p, we isolated multicopy suppressor genes of the cell lethality of the double mutant rgd1Delta mid2Delta. RHO1 and RHO2 encoding two small GTPases, MKK1 encoding one of the MAP-kinase kinases in the protein kinase C (PKC) pathway, and MTL1, a MID2-homolog, were shown to suppress the rgd1Delta defects strengthening the functional links between RGD1 and the cell integrity pathway. Study of the transcriptional activity of Rlm1p, which is under the control of Mpk1p, the last kinase of the PKC pathway, and follow-up of the PST1 transcription, which is positively regulated by Rlm1p, indicate that the lack of RGD1 function diminishes the PKC pathway activity. We hypothesize that the rgd1Delta inactivation, at least through the hyperactivation of the small GTPases Rho3p and Rho4p, alters the secretory pathway and/or the actin cytoskeleton and decreases activity of the PKC pathway. PMID:11779787

  20. Transcription termination factor Rho: a hub linking diverse physiological processes in bacteria.

    PubMed

    Grylak-Mielnicka, Aleksandra; Bidnenko, Vladimir; Bardowski, Jacek; Bidnenko, Elena

    2016-03-01

    Factor-dependent termination of transcription in bacteria relies on the activity of a specific RNA helicase, the termination factor Rho. Rho is nearly ubiquitous in bacteria, but the extent to which its physiological functions are conserved throughout the different phyla remains unknown. Most of our current knowledge concerning the mechanism of Rho's activity and its physiological roles comes from the model micro-organism Escherichia coli, where Rho is essential and involved in the control of several important biological processes. However, the rather comprehensive knowledge about the general mechanisms of action and activities of Rho based on the E. coli paradigm cannot be directly extrapolated to other bacteria. Recent studies performed in different species favour the view that Rho-dependent termination plays a significant role even in bacteria where Rho is not essential. Here, we summarize the current state of the ever-increasing knowledge about the various aspects of the physiological functions of Rho, such as limitation of deleterious foreign DNA expression, control of gene expression, suppression of pervasive transcription, prevention of R-loops and maintenance of chromosome integrity, focusing on similarities and differences of the activities of Rho in various bacterial species. PMID:26796109

  1. Unusually long-lived pause required for regulation of a Rho-dependent transcription terminator

    PubMed Central

    Hollands, Kerry; Sevostiyanova, Anastasia; Groisman, Eduardo A.

    2014-01-01

    Up to half of all transcription termination events in bacteria rely on the RNA-dependent helicase Rho. However, the nucleic acid sequences that promote Rho-dependent termination remain poorly characterized. Defining the molecular determinants that confer Rho-dependent termination is especially important for understanding how such terminators can be regulated in response to specific signals. Here, we identify an extraordinarily long-lived pause at the site where Rho terminates transcription in the 5′-leader region of the Mg2+ transporter gene mgtA in Salmonella enterica. We dissect the sequence elements required for prolonged pausing in the mgtA leader and establish that the remarkable longevity of this pause is required for a riboswitch to stimulate Rho-dependent termination in the mgtA leader region in response to Mg2+ availability. Unlike Rho-dependent terminators described previously, where termination occurs at multiple pause sites, there is a single site of transcription termination directed by Rho in the mgtA leader. Our data suggest that Rho-dependent termination events that are subject to regulation may require elements distinct from those operating at constitutive Rho-dependent terminators. PMID:24778260

  2. Annexin 2 Regulates Intestinal Epithelial Cell Spreading and Wound Closure through Rho-Related Signaling

    PubMed Central

    Babbin, Brian A.; Parkos, Charles A.; Mandell, Kenneth J.; Winfree, L. Matthew; Laur, Oskar; Ivanov, Andrei I.; Nusrat, Asma

    2007-01-01

    Epithelial cell migration is a critical event in gastrointestinal mucosal wound healing and is dependent on actin cytoskeletal reorganization. We observed increased expression of an actin regulatory protein, annexin 2, in migrating intestinal epithelial cells. Small interfering RNA (siRNA)-mediated knockdown of annexin 2 expression in Caco-2 epithelial cells resulted in significant reductions in cell spreading and wound closure associated with decreased formation of filamentous actin bundles along the base of migrating cells. Because annexin 2 has been shown to influences actin cytoskeletal remodeling through targeting signaling molecules to membrane domains, we examined the membrane association and activation status of Rho GTPases after annexin 2 knockdown. We observed Rho dissociation from membranes and decreased Rho activity following annexin 2 siRNA transfection. Inhibition of cell spreading and wound closure in annexin 2 siRNA-transfected cells was prevented by expression of constitutively active RhoA. Rho colocalized with annexin 2 in lamellipodia and along the cytoplasmic face of the plasma membrane. In addition, annexin 2 was observed to co-immunoprecipitate with endogenous Rho and constitutively active RhoA. These findings suggest that annexin 2 plays a role in targeting Rho to cellular membranes, thereby modulating Rho-related signaling events regulating cytoskeletal reorganization during epithelial cell migration. PMID:17322380

  3. The use of GFP to localize Rho GTPases in living cells.

    PubMed

    Michaelson, David; Philips, Mark

    2006-01-01

    The green fluorescent protein (GFP) of the jellyfish Aequorea victoria has revolutionized the study of protein localization and dynamics. GFP fusions permit analysis of proteins in living cells and offer distinct advantages over conventional immunofluorescence. Among these are lower background, higher resolution, robust dual color colocalization, and avoidance of fixation artifacts. In the case of Ras and Rho family proteins, GFP fusions have allowed breakthroughs in the understanding of how CAAX proteins are targeted to specific cell membranes and how signaling at different membranes can result in different cellular responses. GFP-tagged Rho proteins have also been informative in analyzing the interactions with the cytosolic chaperone, RhoGDI. The major disadvantages of studying GFP fusion proteins is that they are generally overexpressed relative to endogenous proteins, and the GFP tag can, in principle, affect protein function. Fortunately, in the case of Ras and Rho family proteins, a GFP tag at the N terminus seems to have little effect on protein targeting and function. Nevertheless, it is prudent to confirm GFP fusion protein data with the study of the endogenous protein. This chapter describes the tagging of Rho proteins with GFP and the analysis of GFP-Rho protein localization by epifluorescence and confocal microscopy. It further describes methods of analyzing endogenous Rho proteins as confirmation of data acquired using GFP-Rho fusion proteins. These techniques will be useful for anyone studying Rho protein function and are widely applicable to many cell types and signal transduction systems. PMID:16472666

  4. RhoA GTPase controls cytokinesis and programmed necrosis of hematopoietic progenitors

    PubMed Central

    Zhou, Xuan; Florian, Maria Carolina; Arumugam, Paritha; Chen, Xiaoyi; Cancelas, Jose A.; Lang, Richard; Malik, Punam; Geiger, Hartmut

    2013-01-01

    Hematopoietic progenitor cells (HPCs) are central to hematopoiesis as they provide large numbers of lineage-defined blood cells necessary to sustain blood homeostasis. They are one of the most actively cycling somatic cells, and their precise control is critical for hematopoietic homeostasis. The small GTPase RhoA is an intracellular molecular switch that integrates cytokine, chemokine, and adhesion signals to coordinate multiple context-dependent cellular processes. By using a RhoA conditional knockout mouse model, we show that RhoA deficiency causes a multilineage hematopoietic failure that is associated with defective multipotent HPCs. Interestingly, RhoA−/− hematopoietic stem cells retained long-term engraftment potential but failed to produce multipotent HPCs and lineage-defined blood cells. This multilineage hematopoietic failure was rescued by reconstituting wild-type RhoA into the RhoA−/− Lin−Sca-1+c-Kit+ compartment. Mechanistically, RhoA regulates actomyosin signaling, cytokinesis, and programmed necrosis of the HPCs, and loss of RhoA results in a cytokinesis failure of HPCs manifested by an accumulation of multinucleated cells caused by failed abscission of the cleavage furrow after telophase. Concomitantly, the HPCs show a drastically increased death associated with increased TNF–RIP-mediated necrosis. These results show that RhoA is a critical and specific regulator of multipotent HPCs during cytokinesis and thus essential for multilineage hematopoiesis. PMID:24101377

  5. Local RhoA activation induces cytokinetic furrows independent of spindle position and cell cycle stage.

    PubMed

    Wagner, Elizabeth; Glotzer, Michael

    2016-06-20

    The GTPase RhoA promotes contractile ring assembly and furrow ingression during cytokinesis. Although many factors that regulate RhoA during cytokinesis have been characterized, the spatiotemporal regulatory logic remains undefined. We have developed an optogenetic probe to gain tight spatial and temporal control of RhoA activity in mammalian cells and demonstrate that cytokinetic furrowing is primarily regulated at the level of RhoA activation. Light-mediated recruitment of a RhoGEF domain to the plasma membrane leads to rapid induction of RhoA activity, leading to assembly of cytokinetic furrows that partially ingress. Furthermore, furrow formation in response to RhoA activation is not temporally or spatially restricted. RhoA activation is sufficient to generate furrows at both the cell equator and cell poles, in both metaphase and anaphase. Remarkably, furrow formation can be initiated in rounded interphase cells, but not adherent cells. These results indicate that RhoA activation is sufficient to induce assembly of functional contractile rings and that cell rounding facilitates furrow formation. PMID:27298323

  6. An RNA motif advances transcription by preventing Rho-dependent termination

    PubMed Central

    Sevostyanova, Anastasia; Groisman, Eduardo A.

    2015-01-01

    The transcription termination factor Rho associates with most nascent bacterial RNAs as they emerge from RNA polymerase. However, pharmacological inhibition of Rho derepresses only a small fraction of these transcripts. What, then, determines the specificity of Rho-dependent transcription termination? We now report the identification of a Rho-antagonizing RNA element (RARE) that hinders Rho-dependent transcription termination. We establish that RARE traps Rho in an inactive complex but does not prevent Rho binding to its recruitment sites. Although translating ribosomes normally block Rho access to an mRNA, inefficient translation of an open reading frame in the leader region of the Salmonella mgtCBR operon actually enables transcription of its associated coding region by favoring an RNA conformation that sequesters RARE. The discovery of an RNA element that inactivates Rho signifies that the specificity of nucleic-acid binding proteins is defined not only by the sequences that recruit these proteins but also by sequences that antagonize their activity. PMID:26630006

  7. Molecular cloning and nucleotide sequence of the 1,2-alpha-D-mannosidase gene, msdS, from Aspergillus saitoi and expression of the gene in yeast cells.

    PubMed

    Inoue, T; Yoshida, T; Ichishima, E

    1995-12-01

    A full-length cDNA encoding 1,2-alpha-D-mannosidase (EC 3.2.1.113) from Aspergillus saitoi was cloned. Analysis of the 1718 bp nucleotide sequence of the cDNA revealed a single open reading frame with 1539 nucleotides of 1,2-alpha-D-mannosidase gene, msdS. The predicted amino-acid sequence of 1,2-alpha-D-mannosidase consists of 513 residues with a molecular mass of 55,767 and is 70%, 26% and 35% identity with those of Penicillium citrinum 1,2-alpha-D-mannosidase, yeast alpha-mannosidase, and mouse alpha-mannosidase. The cDNA of the msdS gene has been cloned and expressed in yeast cells. To identify the activity of expression product methyl-2-O-alpha-mannopyranosyl-alpha-mannopyranoside (Man alpha 1-->2Man-OMe) was used as a substrate at pH 5.0. PMID:8519794

  8. Rho, ROCK and actomyosin contractility in metastasis as drug targets

    PubMed Central

    Bruce, Fanshawe; Sanz-Moreno, Victoria

    2016-01-01

    Metastasis is the spread of cancer cells around the body and the cause of the majority of cancer deaths. Metastasis is a very complex process in which cancer cells need to dramatically modify their cytoskeleton and cope with different environments to successfully colonize a secondary organ. In this review, we discuss recent findings pointing at Rho-ROCK or actomyosin force (or both) as major drivers of many of the steps required for metastatic success. We propose that these are important drug targets that need to be considered in the clinic to palliate metastatic disease. PMID:27158478

  9. Rho-guanine nucleotide exchange factors during development

    PubMed Central

    Mulinari, Shai

    2010-01-01

    The development of multicellular organisms is associated with extensive rearrangements of tissues and cell sheets. The driving force for these rearrangements is generated mostly by the actin cytoskeleton. In order to permit the reproducible development of a specific body plan, dynamic reorganization of the actin cytoskeleton must be precisely coordinated in space and time. GTP-exchange factors that activate small GTPases of the Rho family play an important role in this process. Here we review the role of this class of cytoskeletal regulators during important developmental processes such as epithelial morphogenesis, cytokinesis, cell migration, cell polarity, neuronal growth cone extension and phagocytosis in different model systems. PMID:21686118

  10. Coxiella burnetii Phagocytosis Is Regulated by GTPases of the Rho Family and the RhoA Effectors mDia1 and ROCK

    PubMed Central

    Distel, Jesús S.; Aguilera, Milton O.; Colombo, María I.; Berón, Walter

    2015-01-01

    The GTPases belonging to the Rho family control the actin cytoskeleton rearrangements needed for particle internalization during phagocytosis. ROCK and mDia1 are downstream effectors of RhoA, a GTPase involved in that process. Coxiella burnetii, the etiologic agent of Q fever, is internalized by the host´s cells in an actin-dependent manner. Nevertheless, the molecular mechanism involved in this process has been poorly characterized. This work analyzes the role of different GTPases of the Rho family and some downstream effectors in the internalization of C. burnetii by phagocytic and non-phagocytic cells. The internalization of C. burnetii into HeLa and RAW cells was significantly inhibited when the cells were treated with Clostridium difficile Toxin B which irreversibly inactivates members of the Rho family. In addition, the internalization was reduced in HeLa cells that overexpressed the dominant negative mutants of RhoA, Rac1 or Cdc42 or that were knocked down for the Rho GTPases. The pharmacological inhibition or the knocking down of ROCK diminished bacterium internalization. Moreover, C. burnetii was less efficiently internalized in HeLa cells overexpressing mDia1-N1, a dominant negative mutant of mDia1, while the overexpression of the constitutively active mutant mDia1-ΔN3 increased bacteria uptake. Interestingly, when HeLa and RAW cells were infected, RhoA, Rac1 and mDia1 were recruited to membrane cell fractions. Our results suggest that the GTPases of the Rho family play an important role in C. burnetii phagocytosis in both HeLa and RAW cells. Additionally, we present evidence that ROCK and mDia1, which are downstream effectors of RhoA, are involved in that process. PMID:26674774

  11. Odontogenic Ameloblast-associated Protein (ODAM) Mediates Junctional Epithelium Attachment to Teeth via Integrin-ODAM-Rho Guanine Nucleotide Exchange Factor 5 (ARHGEF5)-RhoA Signaling.

    PubMed

    Lee, Hye-Kyung; Ji, Suk; Park, Su-Jin; Choung, Han-Wool; Choi, Youngnim; Lee, Hyo-Jung; Park, Shin-Young; Park, Joo-Cheol

    2015-06-01

    Adhesion of the junctional epithelium (JE) to the tooth surface is crucial for maintaining periodontal health. Although odontogenic ameloblast-associated protein (ODAM) is expressed in the JE, its molecular functions remain unknown. We investigated ODAM function during JE development and regeneration and its functional significance in the initiation and progression of periodontitis and peri-implantitis. ODAM was expressed in the normal JE of healthy teeth but absent in the pathologic pocket epithelium of diseased periodontium. In periodontitis and peri-implantitis, ODAM was extruded from the JE following onset with JE attachment loss and detected in gingival crevicular fluid. ODAM induced RhoA activity and the expression of downstream factors, including ROCK (Rho-associated kinase), by interacting with Rho guanine nucleotide exchange factor 5 (ARHGEF5). ODAM-mediated RhoA signaling resulted in actin filament rearrangement. Reduced ODAM and RhoA expression in integrin β3- and β6-knockout mice revealed that cytoskeleton reorganization in the JE occurred via integrin-ODAM-ARHGEF5-RhoA signaling. Fibronectin and laminin activated RhoA signaling via the integrin-ODAM pathway. Finally, ODAM was re-expressed with RhoA in regenerating JE after gingivectomy in vivo. These results suggest that ODAM expression in the JE reflects a healthy periodontium and that JE adhesion to the tooth surface is regulated via fibronectin/laminin-integrin-ODAM-ARHGEF5-RhoA signaling. We also propose that ODAM could be used as a biomarker of periodontitis and peri-implantitis. PMID:25911094

  12. Odontogenic Ameloblast-associated Protein (ODAM) Mediates Junctional Epithelium Attachment to Teeth via Integrin-ODAM-Rho Guanine Nucleotide Exchange Factor 5 (ARHGEF5)-RhoA Signaling*

    PubMed Central

    Lee, Hye-Kyung; Ji, Suk; Park, Su-Jin; Choung, Han-Wool; Choi, Youngnim; Lee, Hyo-Jung; Park, Shin-Young; Park, Joo-Cheol

    2015-01-01

    Adhesion of the junctional epithelium (JE) to the tooth surface is crucial for maintaining periodontal health. Although odontogenic ameloblast-associated protein (ODAM) is expressed in the JE, its molecular functions remain unknown. We investigated ODAM function during JE development and regeneration and its functional significance in the initiation and progression of periodontitis and peri-implantitis. ODAM was expressed in the normal JE of healthy teeth but absent in the pathologic pocket epithelium of diseased periodontium. In periodontitis and peri-implantitis, ODAM was extruded from the JE following onset with JE attachment loss and detected in gingival crevicular fluid. ODAM induced RhoA activity and the expression of downstream factors, including ROCK (Rho-associated kinase), by interacting with Rho guanine nucleotide exchange factor 5 (ARHGEF5). ODAM-mediated RhoA signaling resulted in actin filament rearrangement. Reduced ODAM and RhoA expression in integrin β3- and β6-knockout mice revealed that cytoskeleton reorganization in the JE occurred via integrin-ODAM-ARHGEF5-RhoA signaling. Fibronectin and laminin activated RhoA signaling via the integrin-ODAM pathway. Finally, ODAM was re-expressed with RhoA in regenerating JE after gingivectomy in vivo. These results suggest that ODAM expression in the JE reflects a healthy periodontium and that JE adhesion to the tooth surface is regulated via fibronectin/laminin-integrin-ODAM-ARHGEF5-RhoA signaling. We also propose that ODAM could be used as a biomarker of periodontitis and peri-implantitis. PMID:25911094

  13. Cardiac glycoside-induced cell death and Rho/Rho kinase pathway: Implication of different regulation in cancer cell lines.

    PubMed

    Özdemir, Aysun; Şimay, Yaprak Dilber; İbişoğlu, Burçin; Yaren, Biljana; Bülbül, Döne; Ark, Mustafa

    2016-05-01

    Previously, we demonstrated that the Rho/ROCK pathway is involved in ouabain-induced apoptosis in HUVEC. In the current work, we investigated whether the Rho/ROCK pathway is functional during cardiac glycosides-induced cytotoxic effects in cancer cell lines, as well as in non-tumor cells. For that purpose, we evaluated the role of ROCK activation in bleb formation and cell migration over upstream and downstream effectors in addition to ROCK cleavage after cardiac glycosides treatment. All three cardiac glycosides (ouabain, digoxin and bufalin) induced cell death in HeLa and HepG2 cells and increased the formation of blebbing in HeLa cells. In contrast to our previous study, ROCK inhibitor Y27632 did not prevent bleb formation. Observation of ROCK II cleavage after ouabain, digoxin and oxaliplatin treatments in HeLa and/or HepG2 cells suggested that cleavage is independent of cell type and cell death induction. While inhibiting cleavage of ROCK II by the caspase inhibitors z-VAD-fmk, z-VDVAD-fmk and z-DEVD-fmk, evaluation of caspase 2 siRNA ineffectiveness on this truncation indicated that caspase-dependent ROCK II cleavage is differentially regulated in cancer cell lines. In HeLa cells, ouabain induced the activation of ROCK, although it did not induce phosphorylation of ERM, an upstream effector. While Y27632 inhibited the migration of HeLa cells, 10nM ouabain had no effect on cell migration. In conclusion, these findings indicate that the Rho/ROCK pathway is regulated differently in cancer cell lines compared to normal cells during cardiac glycosides-induced cell death. PMID:27017918

  14. Molecular and functional characterization of a Rho GDP dissociation inhibitor in the filamentous fungus Tuber borchii

    PubMed Central

    Menotta, Michele; Amicucci, Antonella; Basili, Giorgio; Polidori, Emanuela; Stocchi, Vilberto; Rivero, Francisco

    2008-01-01

    Background Small GTPases of the Rho family function as tightly regulated molecular switches that govern important cellular functions in eukaryotes. Several families of regulatory proteins control their activation cycle and subcellular localization. Members of the guanine nucleotide dissociation inhibitor (GDI) family sequester Rho GTPases from the plasma membrane and keep them in an inactive form. Results We report on the characterization the RhoGDI homolog of Tuber borchii Vittad., an ascomycetous ectomycorrhizal fungus. The Tbgdi gene is present in two copies in the T. borchii genome. The predicted amino acid sequence shows high similarity to other known RhoGDIs. Real time PCR analyses revealed an increased expression of Tbgdi during the phase preparative to the symbiosis instauration, in particular after stimulation with root exudates extracts, that correlates with expression of Tbcdc42. In a translocation assay TbRhoGDI was able to solubilize TbCdc42 from membranes. Surprisingly, TbRhoGDI appeared not to interact with S. cerevisiae Cdc42, precluding the use of yeast as a surrogate model for functional studies. To study the role of TbRhoGDI we performed complementation experiments using a RhoGDI null strain of Dictyostelium discoideum, a model organism where the roles of Rho signaling pathways are well established. For comparison, complementation with mammalian RhoGDI1 and LyGDI was also studied in the null strain. Although interacting with Rac1 isoforms, TbRhoGDI was not able to revert the defects of the D. discoideum RhoGDI null strain, but displayed an additional negative effect on the cAMP-stimulated actin polymerization response. Conclusion T. borchii expresses a functional RhoGDI homolog that appears as an important modulator of cytoskeleton reorganization during polarized apical growth that antecedes symbiosis instauration. The specificity of TbRhoGDI actions was underscored by its inability to elicit a growth defect in S. cerevisiae or to compensate the

  15. Rho-kinase mediated cytoskeletal stiffness in skinned smooth muscle

    PubMed Central

    Lan, Bo; Wang, Lu; Zhang, Jenny; Pascoe, Chris D.; Norris, Brandon A.; Liu, Jeffrey C.-Y.; Solomon, Dennis; Paré, Peter D.; Deng, Linhong

    2013-01-01

    The structurally dynamic cytoskeleton is important in many cell functions. Large gaps still exist in our knowledge regarding what regulates cytoskeletal dynamics and what underlies the structural plasticity. Because Rho-kinase is an upstream regulator of signaling events leading to phosphorylation of many cytoskeletal proteins in many cell types, we have chosen this kinase as the focus of the present study. In detergent skinned tracheal smooth muscle preparations, we quantified the proteins eluted from the muscle cells over time and monitored the muscle's ability to respond to acetylcholine (ACh) stimulation to produce force and stiffness. In a partially skinned preparation not able to generate active force but could still stiffen upon ACh stimulation, we found that the ACh-induced stiffness was independent of calcium and myosin light chain phosphorylation. This indicates that the myosin light chain-dependent actively cycling crossbridges are not likely the source of the stiffness. The results also indicate that Rho-kinase is central to the ACh-induced stiffness, because inhibition of the kinase by H1152 (1 μM) abolished the stiffening. Furthermore, the rate of relaxation of calcium-induced stiffness in the skinned preparation was faster than that of ACh-induced stiffness, with or without calcium, suggesting that different signaling pathways lead to different means of maintenance of stiffness in the skinned preparation. PMID:24072407

  16. A molecular ruler regulates cytoskeletal remodelling by the Rho kinases

    PubMed Central

    Truebestein, Linda; Elsner, Daniel J.; Fuchs, Elisabeth; Leonard, Thomas A.

    2015-01-01

    The Rho-associated coiled-coil kinases (ROCK) are essential regulators of the actin cytoskeleton; however, the structure of a full-length ROCK is unknown and the mechanisms by which its kinase activity is controlled are not well understood. Here we determine the low-resolution structure of human ROCK2 using electron microscopy, revealing it to be a constitutive dimer, 120 nm in length, with a long coiled-coil tether linking the kinase and membrane-binding domains. We find, in contrast to previous reports, that ROCK2 activity does not appear to be directly regulated by binding to membranes, RhoA, or by phosphorylation. Instead, we show that changing the length of the tether modulates ROCK2 function in cells, suggesting that it acts as a molecular ruler. We present a model in which ROCK activity is restricted to a discrete region of the actin cytoskeleton, governed by the length of its coiled-coil. This represents a new type of spatial control, and hence a new paradigm for kinase regulation. PMID:26620183

  17. Role of Rho small GTPases in meniscus cells.

    PubMed

    Kanazawa, Tomoko; Furumatsu, Takayuki; Matsumoto-Ogawa, Emi; Maehara, Ami; Ozaki, Toshifumi

    2014-11-01

    We previously reported that mechanical stretch regulates Sry-type HMG box (SOX) 9-dependent α1(II) collagen (COL2A1) expression in inner meniscus cells. This study examined the role of the small Rho guanosine 5' triphosphatase Rac1 and Rho-associated kinase (ROCK) in the regulation of stretch-induced SOX9 gene expression in cultured human inner meniscus cells. COL2A1 and SOX9 gene expression was assessed by real-time PCR after application of uni-axial cyclic tensile strain (CTS) in the presence or absence of ROCK and Rac1 inhibitors. The subcellular localization of SOX9 and the Rac1 effector cyclic AMP response element-binding protein (CREB), the phosphorylation state of SOX9, Rac1 activation, and the binding of CREB to the SOX9 promoter were assessed. CTS increased the expression of COL2A1 and SOX9, which was suppressed by inhibition of Rac1. ROCK inhibition enhanced COL2A1 and SOX9 gene expression in the absence of CTS. CTS stimulated the nuclear translocation and phosphorylation of SOX9, and increased Rac1 activation. CTS also increased the binding of CREB to the SOX9 promoter. The results suggest that mechanical stretch-dependent upregulation of SOX9 by CREB in inner meniscus cells depends on the antagonistic activities of ROCK and Rac1. PMID:25130858

  18. Novel Insights into the Roles of Rho Kinase in Cancer.

    PubMed

    Wei, Lei; Surma, Michelle; Shi, Stephanie; Lambert-Cheatham, Nathan; Shi, Jianjian

    2016-08-01

    Rho-associated coiled-coil kinase (ROCK) is a major downstream effector of the small GTPase RhoA. The ROCK family, consisting of ROCK1 and ROCK2, plays a central role in the organization of the actin cytoskeleton, and is involved in a wide range of fundamental cellular functions such as contraction, adhesion, migration, proliferation, and apoptosis. Since the discovery of effective inhibitors such as fasudil and Y27632, the biological roles of ROCK have been extensively explored in numerous diseases, including cancer. Accumulating evidence supports the concept that ROCK plays important roles in tumor development and progression through regulating many key cellular functions associated with malignancy, including tumorigenicity, tumor growth, metastasis, angiogenesis, tumor cell apoptosis/survival and chemoresistance as well. This review focuses on the new advances of the most recent 5 years from the studies on the roles of ROCK in cancer development and progression; the discussion is mainly focused on the potential value of ROCK inhibitors in cancer therapy. PMID:26725045

  19. Structurally Resolved Abundances and Depletions in the Rho OPH Cloud

    NASA Astrophysics Data System (ADS)

    Seab, C.

    1995-07-01

    The mechanism that determines the pattern of depletion ofelements in the interstellar medium has been a problem for along time. It is clear that some of the most refractoryelements such as Si, Fe, and Mg, are heavily depleted onto theinterstellar grains. On the other hand, some elements such asS and Zn are normally either undepleted or very lightlydepleted. The difference between the two cases is notunderstood. We propose to address this question with adetailed study of the depletion patterns in the Rho Ophiuchicloud. This study is strongly based on a combination of thecapabilities of two modern instruments: the GHRS for high-resolution UV data, and the Ultra High Resolution Facility(UHRF) of the AAT. This instrument has been used to obtain NaI line profiles in the Rho Oph cloud with a resolution ofR=1,000,000. The combination of these two types of data willbe used to resolve the velocity structure of the elementdepletions in the cloud.

  20. Fasudil alleviates traumatic optic neuropathy by inhibiting Rho signaling pathway

    PubMed Central

    Yu, Jianglong; Lan, Shiying; Wang, Ruijia; Maier, Aba; Luan, Xinping

    2015-01-01

    Objectives: The present study is to investigate the pathological changes in rabbits with traumatic optic neuropathy (TON), as well as the effect of fasudil on the lesions. Methods: A total of 144 New Zealand rabbits were successfully established as TON models. Twelve hours after surgery, the rabbits in control, dexamethasone, and fasudil groups were administrated with saline, dexamethasone, and fasudil via ear veins, respectively. Then, retinas of the rabbits were obtained at 72 h and on days 7, 14 and 21 after surgery. The pathological changes in retina and optic nerves were observed by hematoxylin and eosin staining and transmission electron microscopy. The expression levels of Rho-associated genes were measured using quantitative real-time polymerase chain reaction. Results: In control group, the axons were swelling, and mitochondria showed vacuolation after optic nerve crush. Mitochondria were swelled slightly in dexamethasone group. By contrast, nerves in fasudil group were repaired. Retinal ganglion cells in control group were reduced significantly due to optic nerve crush. The loss of retinal ganglion cells was alleviated in fasudil group. Quantitative real-time polymerase chain reaction showed that the expression of Rho-associated genes were down-regulated. Conclusions: The present study demonstrates that fasudil inhibits the apoptosis of retinal ganglion cells and ameliorates damages of optic nerves in traumatic optic neuropathy. PMID:26550269

  1. Infrared spectroscopy of solid CO - The Rho Ophiuchi molecular cloud

    NASA Astrophysics Data System (ADS)

    Kerr, T. H.; Adamson, A. J.; Whittet, D. C. B.

    1993-06-01

    Infrared spectra centered on the solid CO feature at 4.76 microns are presented for seven embedded objects in the Rho Oph molecular cloud. Synthetic spectra based on laboratory data for various ice mixtures containing CO are compared with the observations, in an attempt to constrain the abundances of both CO and other grain mantle constituents. The profiles indicate that the CO is embedded in only two types of matrix: pure (or nearly pure) CO, and H2O. A large abundance of CO2 mixed with CO in the mantles is ruled out. There are at least two components to the absorption in most cases, attributed to two or more different grain environments. Column densities of solid CO in these regions are presented, along with upper limits on the depth of the CO feature for a further eight lines of sight in the cloud. The features reflect varying physical and chemical conditions within the Rho Oph cloud. The composite features are fundamentally different within current observational limits from those seen in the Taurus dark cloud.

  2. Direct observation of the translocation mechanism of transcription termination factor Rho

    PubMed Central

    Gocheva, Veronika; Le Gall, Antoine; Boudvillain, Marc; Margeat, Emmanuel; Nollmann, Marcelo

    2015-01-01

    Rho is a ring-shaped, ATP-fueled motor essential for remodeling transcriptional complexes and R-loops in bacteria. Despite years of research on this fundamental model helicase, key aspects of its mechanism of translocation remain largely unknown. Here, we used single-molecule manipulation and fluorescence methods to directly monitor the dynamics of RNA translocation by Rho. We show that the efficiency of Rho activation is strongly dependent on the force applied on the RNA but that, once active, Rho is able to translocate against a large opposing force (at least 7 pN) by a mechanism involving ‘tethered tracking’. Importantly, the ability to directly measure dynamics at the single-molecule level allowed us to determine essential motor properties of Rho. Hence, Rho translocates at a rate of ∼56 nt per second under our experimental conditions, which is 2–5 times faster than velocities measured for RNA polymerase under similar conditions. Moreover, the processivity of Rho (∼62 nt at a 7 pN opposing force) is large enough for Rho to reach termination sites without dissociating from its RNA loading site, potentially increasing the efficiency of transcription termination. Our findings unambiguously establish ‘tethered tracking’ as the main pathway for Rho translocation, support ‘kinetic coupling’ between Rho and RNA polymerase during Rho-dependent termination, and suggest that forces applied on the nascent RNA transcript by cellular substructures could have important implications for the regulation of transcription and its coupling to translation in vivo. PMID:25662222

  3. GPER inhibits diabetes-mediated RhoA activation to prevent vascular endothelial dysfunction.

    PubMed

    Li, Zilin; Cheng, Liang; Liang, Hongliang; Duan, Weixun; Hu, Jing; Zhi, Weiwei; Yang, Jinbao; Liu, Zhenhua; Zhao, Minggao; Liu, Jincheng

    2016-02-01

    The effect of estrogen receptors on diabetes-induced vascular dysfunction is critical, but ambiguous. Individuals with diabetic vascular disease may require estrogen receptor-specific targeted therapy in the future. The G protein-coupled estrogen receptor (GPER) has beneficial effects on vascular function. However, its fundamental mechanisms are unclear. The RhoA/Rho-kinase pathway contributes to diabetic vascular complications, whereas estrogen can suppress Rho-kinase function. Thus, we assumed that GPER inhibits diabetes-mediated RhoA activation to prevent vascular dysfunction. We further investigated the underlying mechanisms involved in this process. Vascular endothelial cells and ex vivo cultured ovariectomized (OVX) C57BL/6 mouse aortae were treated with high glucose (HG) alone or in combination with GPER agonist (G1). G1 treatment was also administered to OVX db/db mice for 8 weeks. An ex-vivo isovolumic myograph was used to analyze the endothelium-dependent vasodilation and endothelium-independent contraction of mouse aortae. Apoptosis, oxidative stress, and inflammation were attenuated in G1-pretreated vascular endothelial cells. G1 significantly decreased the phosphorylation of inhibitory endothelial nitric oxide (NO) synthase residue threonine 495 (eNOS Thr495), inhibited RhoA expression, and increased NO production. Additionally, G1 rescued the impaired endothelium-dependent relaxation and inhibited RhoA activation in the thoracic aorta of OVX db/db mice and ex-vivo cultured OVX C57BL/6 mouse aortae treated with HG. Estrogens acting via GPER could protect vascular endothelium, and GPER activation might elicit ERα-independent effect to inhibit RhoA/Rho-kinase pathway. Additionally, GPER activation might reduce vascular smooth muscle contraction by inhibiting RhoA activation. Thus, the results of the present study suggest a new therapeutic paradigm for end-stage vascular dysfunction by inhibiting RhoA/Rho-kinase pathway via GPER activation. PMID:26785611

  4. Simultaneous and independent tuning of RhoA and Rac1 activity with orthogonally inducible promoters

    PubMed Central

    MacKay, Joanna L.

    2014-01-01

    The GTPases RhoA and Rac1 are key regulators of cell spreading, adhesion, and migration, and they exert distinct effects on the actin cytoskeleton. While RhoA classically stimulates stress fiber assembly and contraction, Rac1 promotes branched actin polymerization and membrane protrusion. These competing influences are reinforced by antagonistic crosstalk between RhoA and Rac1, which has complicated efforts to identify the specific mechanisms by which each GTPase regulates cell behavior. We therefore wondered whether RhoA and Rac1 are intrinsically coupled or whether they can be manipulated independently. To address this question, we placed constitutively active (CA) RhoA under a doxycycline-inducible promoter and CA Rac1 under an orthogonal cumate-inducible promoter, and we stably introduced both constructs into glioblastoma cells. We found that doxycycline addition increased RhoA activity without altering Rac1 and similarly cumate addition increased Rac1 activity without altering RhoA. Furthermore, co-expression of both mutants enabled high activation of RhoA and Rac1 simultaneously. When cells were cultured on collagen hydrogels, RhoA activation prevented cell spreading and motility, whereas Rac1 activation stimulated migration and dynamic cell protrusions. Interestingly, high activation of both GTPases induced a third phenotype, in which cells migrated at intermediate speeds similar to control cells but also aggregated into large, contractile clusters. In addition, we demonstrate dynamic and reversible switching between high RhoA and high Rac1 phenotypes. Overall, this approach represents a unique way to access different combinations of RhoA and Rac1 activity levels in a single cell and may serve as a valuable tool for multiplexed dissection and control of mechanobiological signals. PMID:25044255

  5. Excitation of high-n toroidicity-induced shear Alfven eigenmodes by energetic particles and fusion alpha particles in tokamaks

    SciTech Connect

    Fu, G.Y.; Cheng, C.Z.

    1992-07-01

    The stability of high-n toroidicity-induced shear Alfven eigenmodes (TAE) in the presence of fusion alpha particles or energetic ions in tokamaks is investigated. The TAE modes are discrete in nature and thus can easily tap the free energy associated with energetic particle pressure gradient through wave particle resonant interaction. A quadratic form is derived for the high-n TAE modes using gyro-kinetic equation. The kinetic effects of energetic particles are calculated perturbatively using the ideal MHD solution as the lowest order eigenfunction. The finite Larmor radius (FLR) effects and the finite drift orbit width (FDW) effects are included for both circulating and trapped energetic particles. It is shown that, for circulating particles, FLR and FDW effects have two opposite influences on the stability of the high-n TAE modes. First, they have the usual stabilizing effects by reducing the wave particle interaction strength. Second, they also have destabilizing effects by allowing more particles to resonate with the TAE modes. It is found that the growth rate induced by the circulating alpha particles increase linearly with toroidal mode number n for small {kappa}{sub {theta}}{rho}{sub {alpha}}, and decreases as 1/n for {kappa}{sub {theta}}{rho}{sub {alpha}} {much_gt} 1. The maximum growth rate is obtained at {kappa}{sub {theta}}{rho}{sub {alpha}} on the order of unity and is nearly constant for the range of 0.7 < {upsilon}{sub {alpha}}/{upsilon}{sub A} < 2.5. On the other hand, the trapped particle response is dominated by the precessional drift resonance. The bounce resonant contribution is negligible. The growth rate peaks sharply at the value of {kappa}{sub {theta}}{rho}{sub {alpha}} such that the precessional drift resonance occurs for the most energetic trapped particles. The maximum growth rate due to the energetic trapped particles is comparable to that of circulating particles.

  6. Excitation of high-n toroidicity-induced shear Alfven eigenmodes by energetic particles and fusion alpha particles in tokamaks

    SciTech Connect

    Fu, G.Y.; Cheng, C.Z.

    1992-07-01

    The stability of high-n toroidicity-induced shear Alfven eigenmodes (TAE) in the presence of fusion alpha particles or energetic ions in tokamaks is investigated. The TAE modes are discrete in nature and thus can easily tap the free energy associated with energetic particle pressure gradient through wave particle resonant interaction. A quadratic form is derived for the high-n TAE modes using gyro-kinetic equation. The kinetic effects of energetic particles are calculated perturbatively using the ideal MHD solution as the lowest order eigenfunction. The finite Larmor radius (FLR) effects and the finite drift orbit width (FDW) effects are included for both circulating and trapped energetic particles. It is shown that, for circulating particles, FLR and FDW effects have two opposite influences on the stability of the high-n TAE modes. First, they have the usual stabilizing effects by reducing the wave particle interaction strength. Second, they also have destabilizing effects by allowing more particles to resonate with the TAE modes. It is found that the growth rate induced by the circulating alpha particles increase linearly with toroidal mode number n for small {kappa}{sub {theta}}{rho}{sub {alpha}}, and decreases as 1/n for {kappa}{sub {theta}}{rho}{sub {alpha}} {much gt} 1. The maximum growth rate is obtained at {kappa}{sub {theta}}{rho}{sub {alpha}} on the order of unity and is nearly constant for the range of 0.7 < {upsilon}{sub {alpha}}/{upsilon}{sub A} < 2.5. On the other hand, the trapped particle response is dominated by the precessional drift resonance. The bounce resonant contribution is negligible. The growth rate peaks sharply at the value of {kappa}{sub {theta}}{rho}{sub {alpha}} such that the precessional drift resonance occurs for the most energetic trapped particles. The maximum growth rate due to the energetic trapped particles is comparable to that of circulating particles.

  7. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-04

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  8. Successful prevention of post-transfusion Rh alloimmunization by intravenous Rho (D) immune globulin (WinRho SD).

    PubMed

    Anderson, B; Shad, A T; Gootenberg, J E; Sandler, S G

    1999-03-01

    Alloimmunization to the D blood group antigen following the transfusion of D-positive red blood cells to a D-negative recipient may be prevented in most persons by a prompt and adequate dose of Rho (D) immune globulin (RhIG). Until recently, the only RhIG approved by the US Food and Drug Administration (FDA) for this indication required intramuscular injection, an inconvenient and painful route for the relatively large volume that may be required. We describe the successful prevention of Rh alloimmunization following the unintentional transfusion of D-positive red blood cells to a D-negative infant by the intravenous infusion of WinRho SD, a new RhIG that is FDA-approved for prevention of post-transfusion Rh alloimmunization by intravenous administration. We believe that this more convenient and less painful approach should be the treatment of choice for preventing Rh alloimmunization following the transfusion of D-positive red cells to a D-negative recipient. PMID:10072121

  9. Rho4 interaction with exocyst and septins regulates cell separation in fission yeast.

    PubMed

    Pérez, Pilar; Portales, Elvira; Santos, Beatriz

    2015-05-01

    Rho GTPases are small proteins present in all eukaryotic cells, from yeast to mammals, with a function in actin organization and morphogenetic processes. Schizosaccharomyces pombe Rho4 is not essential but it displays a role during cell separation at high temperature. In fact, Rho4 is involved in the secretion of the hydrolytic enzymes that are required for cell septum degradation during this process. In rho4Δ cells, vesicles accumulate in the septum area and the glucanases Eng1 and Agn1 are not secreted to the culture medium. The localization of Eng1 and Agn1 depends on the exocyst and the septins. The exocyst is a conserved multiprotein complex important for the targeting and fusion of Golgi-derived vesicles with the plasma membrane. Septins are a family of GTP-binding proteins conserved in eukaryotes that function during cytokinesis. Here we show that Rho4 is required for the proper localization of the exocyst and septins at high temperature. Moreover, pull-down experiments demonstrate that Rho4 can interact with exocyst subunits, such as Sec8 and Exo70, and septin proteins, such as Spn3. We observe that Sec8 preferentially binds to activated GTP-Rho4, suggesting that Sec8 could be an effector of this GTPase. We propose that the interaction of Rho4 with the exocyst and septins confers a precise regulation for the secretion of glucanases at the appropriate place and time during the cell cycle. PMID:25724972

  10. 42 CFR 493.859 - Standard; ABO group and D (Rho) typing.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Standard; ABO group and D (Rho) typing. 493.859... SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Participation in Proficiency..., Or Any Combination of These Tests § 493.859 Standard; ABO group and D (Rho) typing. (a) Failure...

  11. Activation of Rac1 by RhoG regulates cell migration.

    PubMed

    Katoh, Hironori; Hiramoto, Kiyo; Negishi, Manabu

    2006-01-01

    Cell migration is essential for normal development and many pathological processes. Rho-family small GTPases play important roles in this event. In particular, Rac regulates lamellipodia formation at the leading edge during migration. The small GTPase RhoG activates Rac through its effector ELMO and the ELMO-binding protein Dock180, which functions as a Rac-specific guanine nucleotide exchange factor. Here we investigated the role of RhoG in cell migration. RNA interference-mediated knockdown of RhoG in HeLa cells reduced cell migration in Transwell and scratch-wound migration assays. In RhoG-knockdown cells, activation of Rac1 and formation of lamellipodia at the leading edge in response to wounding were attenuated. By contrast, expression of active RhoG promoted cell migration through ELMO and Dock180. However, the interaction of Dock180 with Crk was dispensable for the activation of Rac1 and promotion of cell migration by RhoG. Taken together, these results suggest that RhoG contributes to the regulation of Rac activity in migrating cells. PMID:16339170

  12. Differential Activation and Inhibition of RhoA by Fluid Flow Induced Shear Stress in Chondrocytes

    PubMed Central

    Wan, Qiaoqiao; Kim, Seung joon; Yokota, Hiroki; Na, Sungsoo

    2013-01-01

    Physical force environment is a major factor that influences cellular homeostasis and remodeling. It is not well understood, however, as a potential role of force intensities in the induction of cellular mechanotransduction. Using a fluorescence resonance energy transfer (FRET)-based approach, we asked whether activities of GTPase RhoA in chondrocytes are dependent on intensities of flow induced shear stress. We hypothesized that RhoA activities can be either elevated or reduced by selecting different levels of shear stress intensities. The result indicate that C28/I2 chondrocytes have increased RhoA activities in response to high shear stress (10 or 20 dyn/cm2), whereas a decrease in activity was seen with an intermediate shear stress of 5 dyn/cm2. No changes were seen under low shear stress (2 dyn/cm2). The observed 2-level switch of RhoA activities is closely linked to the shear stress-induced alterations in actin cytoskeleton and traction forces. In the presence of constitutively active RhoA (RhoA-V14), intermediate shear stress suppressed RhoA activities, while high shear stress failed to activate them. In chondrocytes, expression of various metalloproteinases is, in part, regulated by shear and normal stresses through a network of GTPases. Collectively, the data suggest that intensities of shear stress are critical in differential activation and inhibition of RhoA activities in chondrocytes. PMID:23408748

  13. Rho-kinase activation in leukocytes plays a pivotal role in myocardial ischemia/reperfusion injury.

    PubMed

    Kitano, Katsunori; Usui, Soichiro; Ootsuji, Hiroshi; Takashima, Shin-ichiro; Kobayashi, Daisuke; Murai, Hisayoshi; Furusho, Hiroshi; Nomura, Ayano; Kaneko, Shuichi; Takamura, Masayuki

    2014-01-01

    The Rho/Rho-kinase pathway plays an important role in many cardiovascular diseases such as hypertension, atherosclerosis, heart failure, and myocardial infarction. Although previous studies have shown that Rho-kinase inhibitors reduce ischemia/reperfusion (I/R) injury and cytokine production, the role of Rho-kinase in leukocytes during I/R injury is not well understood. Mice were subjected to 30-min ischemia and reperfusion. Rho-kinase activity was significantly greater in leukocytes subjected to myocardial I/R compared to the sham-operated mice. Administration of fasudil, a Rho-kinase inhibitor, significantly reduced the I/R-induced expression of the proinflammatory cytokines interleukin (IL)-6, C-C motif chemoattractant ligand 2 (CCL2), and tumor necrosis factor (TNF)-α, in leukocytes, compared with saline as the vehicle. Furthermore, fasudil decreased I/R-induced myocardial infarction/area at risk (IA) and I/R-induced leukocyte infiltration in the myocardium. Interestingly, IA in fasudil-administered mice with leukocyte depletion was similar to that in fasudil-administered mice. I/R also resulted in remarkable increases in the mRNA expression levels of the proinflammatory cytokines TNF-α, IL-6, and CCL2 in the heart. Inhibition of Rho-kinase activation in leukocytes has an important role in fasudil-induced cardioprotective effects. Hence, inhibition of Rho-kinase may be an additional therapeutic intervention for the treatment of acute coronary syndrome. PMID:24638037

  14. Rho-Kinase Activation in Leukocytes Plays a Pivotal Role in Myocardial Ischemia/Reperfusion Injury

    PubMed Central

    Kitano, Katsunori; Usui, Soichiro; Ootsuji, Hiroshi; Takashima, Shin-ichiro; Kobayashi, Daisuke; Murai, Hisayoshi; Furusho, Hiroshi; Nomura, Ayano; Kaneko, Shuichi; Takamura, Masayuki

    2014-01-01

    The Rho/Rho-kinase pathway plays an important role in many cardiovascular diseases such as hypertension, atherosclerosis, heart failure, and myocardial infarction. Although previous studies have shown that Rho-kinase inhibitors reduce ischemia/reperfusion (I/R) injury and cytokine production, the role of Rho-kinase in leukocytes during I/R injury is not well understood. Mice were subjected to 30-min ischemia and reperfusion. Rho-kinase activity was significantly greater in leukocytes subjected to myocardial I/R compared to the sham-operated mice. Administration of fasudil, a Rho-kinase inhibitor, significantly reduced the I/R-induced expression of the proinflammatory cytokines interleukin (IL)-6, C-C motif chemoattractant ligand 2 (CCL2), and tumor necrosis factor (TNF)-α, in leukocytes, compared with saline as the vehicle. Furthermore, fasudil decreased I/R-induced myocardial infarction/area at risk (IA) and I/R-induced leukocyte infiltration in the myocardium. Interestingly, IA in fasudil-administered mice with leukocyte depletion was similar to that in fasudil-administered mice. I/R also resulted in remarkable increases in the mRNA expression levels of the proinflammatory cytokines TNF-α, IL-6, and CCL2 in the heart. Inhibition of Rho-kinase activation in leukocytes has an important role in fasudil-induced cardioprotective effects. Hence, inhibition of Rho-kinase may be an additional therapeutic intervention for the treatment of acute coronary syndrome. PMID:24638037

  15. RhoH Regulates Subcellular Localization of ZAP-70 and Lck in T Cell Receptor Signaling

    PubMed Central

    Chae, Hee-Don; Siefring, Jamie E.; Hildeman, David A.; Gu, Yi; Williams, David A.

    2010-01-01

    RhoH is an hematopoietic-specific, GTPase-deficient Rho GTPase that plays a role in T development. We investigated the mechanisms of RhoH function in TCR signaling. We found that the association between Lck and CD3ζ was impaired in RhoH-deficient T cells, due to defective translocation of both Lck and ZAP-70 to the immunological synapse. RhoH with Lck and ZAP-70 localizes in the detergent-soluble membrane fraction where the complex is associated with CD3ζ phosphorylation. To determine if impaired translocation of ZAP-70 was a major determinant of defective T cell development, Rhoh-/- bone marrow cells were transduced with a chimeric myristoylation-tagged ZAP-70. Myr-ZAP-70 transduced cells partially reversed the in vivo defects of RhoH-associated thymic development and TCR signaling. Together, our results suggest that RhoH regulates TCR signaling via recruitment of ZAP-70 and Lck to CD3ζ in the immunological synapse. Thus, we define a new function for a RhoH GTPase as an adaptor molecule in TCR signaling pathway. PMID:21103055

  16. Binding and translocation of termination factor rho studied at the single-molecule level.

    PubMed

    Koslover, Daniel J; Fazal, Furqan M; Mooney, Rachel A; Landick, Robert; Block, Steven M

    2012-11-01

    Rho termination factor is an essential hexameric helicase responsible for terminating 20-50% of all mRNA synthesis in Escherichia coli. We used single-molecule force spectroscopy to investigate Rho-RNA binding interactions at the Rho utilization site of the λtR1 terminator. Our results are consistent with Rho complexes adopting two states: one that binds 57 ± 2nt of RNA across all six of the Rho primary binding sites, and another that binds 85 ± 2nt at the six primary sites plus a single secondary site situated at the center of the hexamer. The single-molecule data serve to establish that Rho translocates 5'→3' toward RNA polymerase (RNAP) by a tethered-tracking mechanism, looping out the intervening RNA between the Rho utilization site and RNAP. These findings lead to a general model for Rho binding and translocation and establish a novel experimental approach that should facilitate additional single-molecule studies of RNA-binding proteins. PMID:22885804

  17. A multipronged strategy of an anti-terminator protein to overcome Rho-dependent transcription termination

    PubMed Central

    Muteeb, Ghazala; Dey, Debashish; Mishra, Saurabh; Sen, Ranjan

    2012-01-01

    One of the important role of Rho-dependent transcription termination in bacteria is to prevent gene expressions from the bacteriophage DNA. The transcription anti-termination systems of the lambdoid phages have been designed to overcome this Rho action. The anti-terminator protein N has three interacting regions, which interact with the mRNA, with the NusA and with the RNA polymerase. Here, we show that N uses all these interaction modules to overcome the Rho action. N and Rho co-occupy their overlapping binding sites on the nascent RNA (the nutR/tR1 site), and this configuration slows down the rate of ATP hydrolysis and the rate of RNA release by Rho from the elongation complex. N-RNA polymerase interaction is not too important for this Rho inactivation process near/at the nutR site. This interaction becomes essential when the elongation complex moves away from the nutR site. From the unusual NusA-dependence property of a Rho mutant E134K, a suppressor of N, we deduced that the N-NusA complex in the anti-termination machinery reduces the efficiency of Rho by removing NusA from the termination pathway. We propose that NusA-remodelling is also one of the mechanisms used by N to overcome the termination signals. PMID:23024214

  18. Rho GTPase/Rho Kinase Negatively Regulates Endothelial Nitric Oxide Synthase Phosphorylation through the Inhibition of Protein Kinase B/Akt in Human Endothelial Cells

    PubMed Central

    Ming, Xiu-Fen; Viswambharan, Hema; Barandier, Christine; Ruffieux, Jean; Kaibuchi, Kozo; Rusconi, Sandro; Yang, Zhihong

    2002-01-01

    Endothelial nitric oxide synthase (eNOS) is an important regulator of cardiovascular homeostasis by production of nitric oxide (NO) from vascular endothelial cells. It can be activated by protein kinase B (PKB)/Akt via phosphorylation at Ser-1177. We are interested in the role of Rho GTPase/Rho kinase (ROCK) pathway in regulation of eNOS expression and activation. Using adenovirus-mediated gene transfer in human umbilical vein endothelial cells (HUVECs), we show here that both active RhoA and ROCK not only downregulate eNOS gene expression as reported previously but also inhibit eNOS phosphorylation at Ser-1177 and cellular NO production with concomitant suppression of PKB activation. Moreover, coexpression of a constitutive active form of PKB restores the phosphorylation but not gene expression of eNOS in the presence of active RhoA. Furthermore, we show that thrombin inhibits eNOS phosphorylation, as well as expression via Rho/ROCK pathway. Expression of the active PKB reverses eNOS phosphorylation but has no effect on downregulation of eNOS expression induced by thrombin. Taken together, these data demonstrate that Rho/ROCK pathway negatively regulates eNOS phosphorylation through inhibition of PKB, whereas it downregulates eNOS expression independent of PKB. PMID:12446767

  19. RhoA as a Mediator of Clinically Relevant Androgen Action in Prostate Cancer Cells

    PubMed Central

    Schmidt, Lucy J.; Duncan, Kelly; Yadav, Neelu; Regan, Kevin M.; Verone, Alissa R.; Lohse, Christine M.; Pop, Elena A.; Attwood, Kristopher; Wilding, Gregory; Mohler, James L.; Sebo, Thomas J.; Tindall, Donald J.

    2012-01-01

    Recently, we have identified serum response factor (SRF) as a mediator of clinically relevant androgen receptor (AR) action in prostate cancer (PCa). Genes that rely on SRF for androgen responsiveness represent a small fraction of androgen-regulated genes, but distinguish benign from malignant prostate, correlate with aggressive disease, and are associated with biochemical recurrence. Thus, understanding the mechanism(s) by which SRF conveys androgen regulation to its target genes may provide novel opportunities to target clinically relevant androgen signaling. Here, we show that the small GTPase ras homolog family member A (RhoA) mediates androgen-responsiveness of more than half of SRF target genes. Interference with expression of RhoA, activity of the RhoA effector Rho-associated coiled-coil containing protein kinase 1 (ROCK), and actin polymerization necessary for nuclear translocation of the SRF cofactor megakaryocytic acute leukemia (MAL) prevented full androgen regulation of SRF target genes. Androgen treatment induced RhoA activation, increased the nuclear content of MAL, and led to MAL recruitment to the promoter of the SRF target gene FHL2. In clinical specimens RhoA expression was higher in PCa cells than benign prostate cells, and elevated RhoA expression levels were associated with aggressive disease features and decreased disease-free survival after radical prostatectomy. Overexpression of RhoA markedly increased the androgen-responsiveness of select SRF target genes, in a manner that depends on its GTPase activity. The use of isogenic cell lines and a xenograft model that mimics the transition from androgen-stimulated to castration-recurrent PCa indicated that RhoA levels are not altered during disease progression, suggesting that RhoA expression levels in the primary tumor determine disease aggressiveness. Androgen-responsiveness of SRF target genes in castration-recurrent PCa cells continued to rely on AR, RhoA, SRF, and MAL and the presence of

  20. Molecular characterization of a novel RhoGAP, RRC-1 of the nematode Caenorhabditis elegans

    SciTech Connect

    Delawary, Mina; Nakazawa, Takanobu; Tezuka, Tohru; Sawa, Mariko; Iino, Yuichi; Takenawa, Tadaomi; Yamamoto, Tadashi . E-mail: tyamamot@ims.u-tokyo.ac.jp

    2007-06-01

    The GTPase-activating proteins for Rho family GTPases (RhoGAP) transduce diverse intracellular signals by negatively regulating Rho family GTPase-mediated pathways. In this study, we have cloned and characterized a novel RhoGAP for Rac1 and Cdc42, termed RRC-1, from Caenorhabditis elegans. RRC-1 was highly homologous to mammalian p250GAP and promoted GTP hydrolysis of Rac1 and Cdc42 in cells. The rrc-1 mRNA was expressed in all life stages. Using an RRC-1::GFP fusion protein, we found that RRC-1 was localized to the coelomocytes, excretory cell, GLR cells, and uterine-seam cell in adult worms. These data contribute toward understanding the roles of Rho family GTPases in C. elegans.

  1. Always look on the bright site of Rho: structural implications for a conserved intermolecular interface.

    PubMed

    Dvorsky, Radovan; Ahmadian, Mohammad Reza

    2004-12-01

    The signalling functions of Rho-family GTPases are based on the formation of distinctive protein-protein complexes. Invaluable insights into the structure-function relationships of the Rho GTPases have been obtained through the resolution of several of their structures in complex with regulators and downstream effectors. In this review, we use these complexes to compare the binding and specificity-determining sites of the Rho GTPases. Although the properties that characterize these sites are diverse, some fundamental conserved principles that govern their intermolecular interactions have emerged. Notably, all of the interacting partners of the Rho GTPases, irrespective of their function, bind to a common set of conserved amino acids that are clustered on the surface of the switch regions. This conserved region and its specific structural characteristics exemplify the convergence of the Rho GTPases on a consensus binding site. PMID:15577926

  2. Arachidonic acid stimulates formation of a novel complex containing nucleolin and RhoA.

    PubMed

    Garcia, Melissa C; Williams, Jason; Johnson, Katina; Olden, Kenneth; Roberts, John D

    2011-02-18

    Arachidonic acid (AA) stimulates cell adhesion through a p38 mitogen activated protein kinase-mediated RhoA signaling pathway. Here we report that a proteomic screen following AA-treatment identified nucleolin, a multifunctional nucleolar protein, in a complex with the GTPase, RhoA, that also included the Rho kinase, ROCK. AA-stimulated cell adhesion was inhibited by expression of nucleolin-targeted shRNA and formation of the multiprotein complex was blocked by expression of dominant-negative RhoA. AA-treatment also induced ROCK-dependent serine phosphorylation of nucleolin and translocation of nucleolin from the nucleus to the cytoplasm, where it appeared to co-localize with RhoA. These data suggest the existence of a new signaling pathway through which the location and post-translational state of nucleolin are modulated. PMID:21281639

  3. Tyrosine Phosphorylation of SGEF Regulates RhoG Activity and Cell Migration

    PubMed Central

    Okuyama, Yusuke; Umeda, Kentaro; Negishi, Manabu; Katoh, Hironori

    2016-01-01

    SGEF and Ephexin4 are members of the Ephexin subfamily of RhoGEFs that specifically activate the small GTPase RhoG. It is reported that Ephexin1 and Ephexin5, two well-characterized Ephexin subfamily RhoGEFs, are tyrosine-phosphorylated by Src, and that their phosphorylation affect their activities and functions. In this study, we show that SGEF, but not Ephexin4, is tyrosine-phosphorylated by Src. Tyrosine phosphorylation of SGEF suppresses its interaction with RhoG, the elevation of RhoG activity, and SGEF-mediated promotion of cell migration. We identified tyrosine 530 (Y530), which is located within the Dbl homology domain, as a major phosphorylation site of SGEF by Src, and Y530F mutation blocked the inhibitory effect of Src on SGEF. Taken together, these results suggest that the activity of SGEF is negatively regulated by tyrosine phosphorylation of the DH domain. PMID:27437949

  4. Rap1 Spatially Controls ArhGAP29 To Inhibit Rho Signaling during Endothelial Barrier Regulation

    PubMed Central

    Post, A.; Pannekoek, W. J.; Ponsioen, B.; Vliem, M. J.

    2015-01-01

    The small GTPase Rap1 controls the actin cytoskeleton by regulating Rho GTPase signaling. We recently established that the Rap1 effectors Radil and Rasip1, together with the Rho GTPase activating protein ArhGAP29, mediate Rap1-induced inhibition of Rho signaling in the processes of epithelial cell spreading and endothelial barrier function. Here, we show that Rap1 induces the independent translocations of Rasip1 and a Radil-ArhGAP29 complex to the plasma membrane. This results in the formation of a multimeric protein complex required for Rap1-induced inhibition of Rho signaling and increased endothelial barrier function. Together with the previously reported spatiotemporal control of the Rap guanine nucleotide exchange factor Epac1, these findings elucidate a signaling pathway for spatiotemporal control of Rho signaling that operates by successive protein translocations to and complex formation at the plasma membrane. PMID:25963656

  5. The Human Minor Histocompatibility Antigen1 Is a RhoGAP

    PubMed Central

    de Kreuk, Bart-Jan; Schaefer, Antje; Anthony, Eloise C.; Tol, Simon; Fernandez-Borja, Mar; Geerts, Dirk; Pool, Jos; Hambach, Lothar; Goulmy, Els; Hordijk, Peter L.

    2013-01-01

    The human minor Histocompatibility Antigen HMHA-1 is a major target of immune responses after allogeneic stem cell transplantation applied for the treatment of leukemia and solid tumors. The restriction of its expression to hematopoietic cells and many solid tumors raised questions regarding its cellular functions. Sequence analysis of the HMHA-1 encoding HMHA1 protein revealed the presence of a possible C-terminal RhoGTPase Activating Protein (GAP) domain and an N-terminal BAR domain. Rho-family GTPases, including Rac1, Cdc42, and RhoA are key regulators of the actin cytoskeleton and control cell spreading and migration. RhoGTPase activity is under tight control as aberrant signaling can lead to pathology, including inflammation and cancer. Whereas Guanine nucleotide Exchange Factors (GEFs) mediate the exchange of GDP for GTP resulting in RhoGTPase activation, GAPs catalyze the low intrinsic GTPase activity of active RhoGTPases, resulting in inactivation. Here we identify the HMHA1 protein as a novel RhoGAP. We show that HMHA1 constructs, lacking the N-terminal region, negatively regulate the actin cytoskeleton as well as cell spreading. Furthermore, we show that HMHA1 regulates RhoGTPase activity in vitro and in vivo. Finally, we demonstrate that the HMHA1 N-terminal BAR domain is auto-inhibitory as HMHA1 mutants lacking this region, but not full-length HMHA1, showed GAP activity towards RhoGTPases. In conclusion, this study shows that HMHA1 acts as a RhoGAP to regulate GTPase activity, cytoskeletal remodeling and cell spreading, which are crucial functions in normal hematopoietic and cancer cells. PMID:24086303

  6. RhoA Ambivalently Controls Prominent Myofibroblast Characteritics by Involving Distinct Signaling Routes

    PubMed Central

    Jatho, Aline; Hartmann, Svenja; Kittana, Naim; Mügge, Felicitas; Wuertz, Christina M.; Tiburcy, Malte; Zimmermann, Wolfram-Hubertus; Katschinski, Dörthe M.; Lutz, Susanne

    2015-01-01

    Introduction RhoA has been shown to be beneficial in cardiac disease models when overexpressed in cardiomyocytes, whereas its role in cardiac fibroblasts (CF) is still poorly understood. During cardiac remodeling CF undergo a transition towards a myofibroblast phenotype thereby showing an increased proliferation and migration rate. Both processes involve the remodeling of the cytoskeleton. Since RhoA is known to be a major regulator of the cytoskeleton, we analyzed its role in CF and its effect on myofibroblast characteristics in 2 D and 3D models. Results Downregulation of RhoA was shown to strongly affect the actin cytoskeleton. It decreased the myofibroblast marker α-sm-actin, but increased certain fibrosis-associated factors like TGF-β and collagens. Also, the detailed analysis of CTGF expression demonstrated that the outcome of RhoA signaling strongly depends on the involved stimulus. Furthermore, we show that proliferation of myofibroblasts rely on RhoA and tubulin acetylation. In assays accessing three different types of migration, we demonstrate that RhoA/ROCK/Dia1 are important for 2D migration and the repression of RhoA and Dia1 signaling accelerates 3D migration. Finally, we show that a downregulation of RhoA in CF impacts the viscoelastic and contractile properties of engineered tissues. Conclusion RhoA positively and negatively influences myofibroblast characteristics by differential signaling cascades and depending on environmental conditions. These include gene expression, migration and proliferation. Reduction of RhoA leads to an increased viscoelasticity and a decrease in contractile force in engineered cardiac tissue. PMID:26448568

  7. RhoA GTPase interacts with beta-catenin signaling in clinorotated osteoblasts

    PubMed Central

    Wan, Qiaoqiao; Cho, Eunhye; Yokota, Hiroki; Na, Sungsoo

    2014-01-01

    Bone is a dynamic tissue under constant remodeling in response to various signals including mechanical loading. A lack of proper mechanical loading induces disuse osteoporosis that reduces bone mass and structural integrity. β-catenin signaling together with a network of GTPases is known to play a primary role in load-driven bone formation, but little is known about potential interactions of β-catenin signaling and GTPases in bone loss. In this study, we addressed a question: Does unloading suppress an activation level of RhoA GTPase and β-catenin signaling in osteoblasts? If yes, what is the role of RhoA GTPase and actin filaments in osteoblasts in regulating β-catenin signaling? Using a fluorescence resonance energy transfer (FRET) technique with a biosensor for RhoA together with a fluorescent T-cell factor/lymphoid enhancer factor (TCF/LEF) reporter, we examined the effects of clinostat-driven simulated unloading. The results revealed that both RhoA activity and TCF/LEF activity were downregulated by unloading. Reduction in RhoA activity was correlated to a decrease in cytoskeletal organization of actin filaments. Inhibition of β-catenin signaling blocked unloading-induced RhoA suppression, and dominant negative RhoA inhibited TCF/LEF suppression. On the other hand, a constitutively active RhoA enhanced unloading-induced reduction of TCF/LEF activity. The TCF/LEF suppression by unloading was enhanced by co-culture with osteocytes, but it was independent on organization of actin filaments, myosin II activity, or a myosin light chain kinase. Collectively, the results suggest that β-catenin signaling is required for unloading-driven regulation of RhoA, and RhoA, but not actin cytoskeleton or intracellular tension, mediates the responsiveness of β-catenin signaling to unloading. PMID:23529802

  8. Observations of neutral atoms in the Rho Ophiuchi cloud

    NASA Technical Reports Server (NTRS)

    Snow, T. P.; Joseph, C. L.; Meyer, D. M.

    1986-01-01

    New observations of lines from neutral atoms in the lines of sight to three stars in the Rho Oph cloud are combined with literature data to look for evidence of density-enhanced regions with higher elemental depletions than those characterizing the cloud as a whole. The depletions inferred from neutral species, however, are comparable to those measured directly from observations of ions, suggesting that no strong density enhancements exist in the observed lines of sight. This conclusion is supported by electron densities derived from the observed ionization fractions, which also show no evidence for a strong variation of density with depth in the cloud. It appears that the overall density (and overall level of depletion) in the cloud is higher than in typical diffuse clouds, despite the apparent lack of strong condensations with enhanced relative depletions.

  9. Reversed Crystal Growth of RHO Zeolitic Imidazolate Framework (ZIF).

    PubMed

    Self, Katherine; Telfer, Michael; Greer, Heather F; Zhou, Wuzong

    2015-12-21

    RHO zeolitic imidazolate framework (ZIF), Zn1.33 (O.OH)0.33 (nim)1.167 (pur), crystals with a rhombic dodecahedral morphology were synthesized by a solvothermal process. The growth of the crystals was studied over time using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD) and Brunauer-Emmett-Teller (BET) analyses, and a reversed crystal growth mechanism was revealed. Initially, precursor materials joined together to form disordered aggregates, which then underwent surface recrystallization forming a core-shell structure, in which a disordered core is encased in a layer of denser, less porous crystal. When the growth continued, the shell became less and less porous, until it was a layer of true single crystal. The crystallization then extended from the surface to the core over a six-week period until, eventually, true single crystals were formed. PMID:26577835

  10. Reversed Crystal Growth of RHO Zeolitic Imidazolate Framework (ZIF)

    PubMed Central

    Self, Katherine; Telfer, Michael; Greer, Heather F.

    2015-01-01

    Abstract RHO zeolitic imidazolate framework (ZIF), Zn1.33(O.OH)0.33(nim)1.167(pur), crystals with a rhombic dodecahedral morphology were synthesized by a solvothermal process. The growth of the crystals was studied over time using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X‐ray diffraction (PXRD) and Brunauer–Emmett–Teller (BET) analyses, and a reversed crystal growth mechanism was revealed. Initially, precursor materials joined together to form disordered aggregates, which then underwent surface recrystallization forming a core–shell structure, in which a disordered core is encased in a layer of denser, less porous crystal. When the growth continued, the shell became less and less porous, until it was a layer of true single crystal. The crystallization then extended from the surface to the core over a six‐week period until, eventually, true single crystals were formed. PMID:26577835

  11. The depletion of calcium in the Rho Ophiuchi cloud

    NASA Technical Reports Server (NTRS)

    Snow, T. P.; Seab, C. G.; Timothy, J. G.

    1983-01-01

    Data on the interstellar Ca II H and K lines toward HD 147889, a star deeply embedded in the rho Ophiuchi dark cloud, were obtained at the Mauna Kea Observatory of the University of Hawaii, using a multi-anode microchannel array (MAMA) detector. An upper limit on the Ca II column density of 1.7 x 10 to the 11th/sq cm was derived, which, together with ionization considerations and an estimated lower limit on the total hydrogen column density, implies that the calcium-to-hydrogen ratio in this line of sight is 0.00000795 or less, relative to the solar value. The logarithmic depletion is up to -5.10, the largest yet measured, and implies that gas-grain interaction in this region has proceeded to a much greater degree than is typical of diffuse clouds.

  12. Depletion of calcium in the Rho Ophiuchi cloud

    SciTech Connect

    Snow, T.P.; Timothy, J.G.; Seab, C.G.

    1983-02-15

    Data on the interstellar Ca II H and K lines toward HD 147889, a star deeply embedded in the rho Ophiuchi dark cloud, were obtained at the Mauna Kea Observatory of the University of Hawaii, using a multi-anode microchannel array (MAMA) detector. An upper limit on the Ca II column density of 1.7 x 10/sup 11/ cm/sup -2/ was derived, which, together with ionization considerations (published elsewhere) and an estimated lower limit on the total hydrogen column density, implies that the calcium-to-hydrogen ratio in this line of sight is 7.95 x 10/sup -6/ or less, relative to the solar value. The logarithmic depletion is < or =-5.10, the largest yet measured, and implies that gas-grain interaction in this region has proceeded to a much greater degree than is typical of diffuse clouds.

  13. Modulation of osteoclast differentiation and bone resorption by Rho GTPases

    PubMed Central

    Touaitahuata, Heiani; Blangy, Anne; Vives, Virginie

    2014-01-01

    Bone is a dynamic tissue constantly renewed through a regulated balance between bone formation and resorption. Excessive bone degradation by osteoclasts leads to pathological decreased bone density characteristic of osteolytic diseases such as post-menopausal osteoporosis or bone metastasis. Osteoclasts are multinucleated cells derived from hematopoietic stem cells via a complex differentiation process. Their unique ability to resorb bone is dependent on the formation of the actin-rich sealing zone. Within this adhesion structure, the plasma membrane differentiates into the ruffled border where protons and proteases are secreted to demineralize and degrade bone, respectively. On the bone surface, mature osteoclasts alternate between stationary resorptive and migratory phases. These are associated with profound actin cytoskeleton reorganization, until osteoclasts die of apoptosis. In this review, we highlight the role of Rho GTPases in all the steps of osteoclasts differentiation, function, and death and conclude on their interest as targets for treatment of osteolytic pathologies. PMID:24614674

  14. Rho-associated kinase inhibitors: a novel glaucoma therapy.

    PubMed

    Inoue, Toshihiro; Tanihara, Hidenobu

    2013-11-01

    The rho-associated kinase (ROCK) signaling pathway is activated via secreted bioactive molecules or via integrin activation after extracellular matrix binding. These lead to polymerization of actin stress fibers and formation of focal adhesions. Accumulating evidence suggests that actin cytoskeleton-modulating signals are involved in aqueous outflow regulation. Aqueous humor contains various biologically active factors, some of which are elevated in glaucomatous eyes. These factors affect aqueous outflow, in part, through ROCK signaling modulation. Various drugs acting on the cytoskeleton have also been shown to increase aqueous outflow by acting directly on outflow tissue. In vivo animal studies have shown that the trabecular meshwork (TM) actin cytoskeleton in glaucomatous eyes is more disorganized and more randomly oriented than in non-glaucomatous control eyes. In a previous study, we introduced ROCK inhibitors as a potential glaucoma therapy by showing that a selective ROCK inhibitor significantly lowered rabbit IOP. Rho-associated kinase inhibitors directly affect the TM and Schlemm's canal (SC), differing from the target sight of other glaucoma drugs. The TM is affected earlier and more strongly than ciliary muscle cells by ROCK inhibitors, largely because of pharmacological affinity differences stemming from regulatory mechanisms. Additionally, ROCK inhibitors disrupt tight junctions, result in F-actin depolymerization, and modulate intracellular calcium level, effectively increasing SC-cell monolayer permeability. Perfusion of an enucleated eye with a ROCK inhibitor resulted in wider empty spaces in the juxtacanalicular (JCT) area and more giant vacuoles in the endothelial cells of SC, while the endothelial lining of SC was intact. Interestingly, ROCK inhibitors also increase retinal blood flow by relaxing vascular smooth muscle cells, directly protecting neurons against various stresses, while promoting wound healing. These additional effects may help

  15. Blunted activation of Rho-kinase in yak pulmonary circulation.

    PubMed

    Ishizaki, Takeshi; Mizuno, Shiro; Sakai, Akio; Matsukawa, Shigeru; Kojonazarov, Baktybek; Zamirbek, Baiserkeev; Umeda, Yukihiro; Morikawa, Miwa; Anzai, Masaki; Ishizuka, Tamotsu; Aldashev, Almaz

    2015-01-01

    Yaks have adapted to high altitude and they do not develop hypoxic pulmonary hypertension. Although we previously identified the important role of augmented nitric oxide synthase activity in the yak pulmonary circulatory system, evidence of the direct involvement of Rho-kinase as a basal vascular tone regulator is lacking. Four domesticated male pure-bred yaks and four bulls that were born and raised at an altitude of 3000 m in the Tien-Shan mountains were studied at an altitude of 3,100 m. Mean pulmonary artery pressure (mPAP) was measured before and after fasudil (60 mg in 20 mL of saline) was intravenously administered using a Swan-Ganz catheter at a rate of 3.3 mL/min for 30 min. Fasudil decreased mPAP in bulls from 67.8±14.9 to 32.3±5.3 mmHg (P < 0.05) after 15 min and the level was maintained for 30 min, but it merely blunted mPAP in yaks from 28.2±4.5 to 25.1±11.1 and 23.2±2.7 mmHg after 5 and 30 min, respectively. These findings comprise the first evidence of a modest role of Rho-kinase in the maintenance of pulmonary artery pressure in the yak. PMID:25654121

  16. Blunted Activation of Rho-Kinase in Yak Pulmonary Circulation

    PubMed Central

    Sakai, Akio; Matsukawa, Shigeru; Zamirbek, Baiserkeev; Umeda, Yukihiro; Morikawa, Miwa; Anzai, Masaki; Ishizuka, Tamotsu; Aldashev, Almaz

    2015-01-01

    Yaks have adapted to high altitude and they do not develop hypoxic pulmonary hypertension. Although we previously identified the important role of augmented nitric oxide synthase activity in the yak pulmonary circulatory system, evidence of the direct involvement of Rho-kinase as a basal vascular tone regulator is lacking. Four domesticated male pure-bred yaks and four bulls that were born and raised at an altitude of 3000 m in the Tien-Shan mountains were studied at an altitude of 3,100 m. Mean pulmonary artery pressure (mPAP) was measured before and after fasudil (60 mg in 20 mL of saline) was intravenously administered using a Swan-Ganz catheter at a rate of 3.3 mL/min for 30 min. Fasudil decreased mPAP in bulls from 67.8±14.9 to 32.3±5.3 mmHg (P < 0.05) after 15 min and the level was maintained for 30 min, but it merely blunted mPAP in yaks from 28.2±4.5 to 25.1±11.1 and 23.2±2.7 mmHg after 5 and 30 min, respectively. These findings comprise the first evidence of a modest role of Rho-kinase in the maintenance of pulmonary artery pressure in the yak. PMID:25654121

  17. Ab initio alpha-alpha scattering

    NASA Astrophysics Data System (ADS)

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A.; Luu, Thomas; Meißner, Ulf-G.

    2015-12-01

    Processes such as the scattering of alpha particles (4He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei—nuclei with even and equal numbers of protons and neutrons—is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the ‘adiabatic projection method’ to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  18. Ab initio alpha-alpha scattering.

    PubMed

    Elhatisari, Serdar; Lee, Dean; Rupak, Gautam; Epelbaum, Evgeny; Krebs, Hermann; Lähde, Timo A; Luu, Thomas; Meißner, Ulf-G

    2015-12-01

    Processes such as the scattering of alpha particles ((4)He), the triple-alpha reaction, and alpha capture play a major role in stellar nucleosynthesis. In particular, alpha capture on carbon determines the ratio of carbon to oxygen during helium burning, and affects subsequent carbon, neon, oxygen, and silicon burning stages. It also substantially affects models of thermonuclear type Ia supernovae, owing to carbon detonation in accreting carbon-oxygen white-dwarf stars. In these reactions, the accurate calculation of the elastic scattering of alpha particles and alpha-like nuclei--nuclei with even and equal numbers of protons and neutrons--is important for understanding background and resonant scattering contributions. First-principles calculations of processes involving alpha particles and alpha-like nuclei have so far been impractical, owing to the exponential growth of the number of computational operations with the number of particles. Here we describe an ab initio calculation of alpha-alpha scattering that uses lattice Monte Carlo simulations. We use lattice effective field theory to describe the low-energy interactions of protons and neutrons, and apply a technique called the 'adiabatic projection method' to reduce the eight-body system to a two-cluster system. We take advantage of the computational efficiency and the more favourable scaling with system size of auxiliary-field Monte Carlo simulations to compute an ab initio effective Hamiltonian for the two clusters. We find promising agreement between lattice results and experimental phase shifts for s-wave and d-wave scattering. The approximately quadratic scaling of computational operations with particle number suggests that it should be possible to compute alpha scattering and capture on carbon and oxygen in the near future. The methods described here can be applied to ultracold atomic few-body systems as well as to hadronic systems using lattice quantum chromodynamics to describe the interactions of

  19. The Rho guanine exchange factor RHGF-2 acts through the Rho-binding kinase LET-502 to mediate embryonic elongation in C. elegans.

    PubMed

    Chan, Benjamin G; Rocheleau, Simon K; Smit, Ryan B; Mains, Paul E

    2015-09-15

    Morphogenesis allows an organism to develop its final body shape. In Caenorhabditis elegans, a smooth muscle-like contraction of an actin/myosin network in the epidermis mediates the elongation of the worm embryo from a ball of cells into a long, thin worm. This process is controlled by two redundant pathways, one involving the small GTPase RHO-1 and its downstream effectors LET-502/Rho-binding kinase and MEL-11/myosin phosphatase, and another involving PAK-1/p21 activated kinase and FEM-2/PP2c phosphatase. Contraction occurs primarily in the lateral epidermal cells during elongation while the dorsal and ventral epidermal cells have a more passive role, and localized activity of a Rho GEF (guanine exchange factor) could contribute to this asymmetry. We found that loss of the C. elegans Rho GEF encoded by rhgf-2 results in arrest during early elongation. Genetically, rhgf-2 acts as an activator of let-502/Rho-binding kinase, in parallel to fem-2/PP2c phosphatase. Although expressed throughout the embryo, lateral cell-specific RHGF-2 expression can mediate elongation. The Rho GTPase activating protein (GAP) RGA-2 is known to inhibit contraction in the dorsal and ventral epidermis. Although rhgf-2 and rga-2 are individually lethal, the double mutant is viable with elongation still occurring in a let-502 dependent fashion. This indicates that LET-502/Rho-binding kinase has activity independent of the GEF and GAP. Finally, maternal LET-502 and MEL-11 are known to regulate the rate of cleavage furrow ingression in the early embryo and we show that maternal RHGF-2 also influences cleavage but RGA-2 does not. Thus while the LET-502/MEL-11 pathway is employed multiple times during embryogenesis, regulation by GEFs and GAPs differs at different points of the life cycle and fine tunes contractile function. PMID:26188247

  20. Simvastatin Increases Fibulin-2 Expression in Human Coronary Artery Smooth Muscle Cells via RhoA/Rho-Kinase Signaling Pathway Inhibition

    PubMed Central

    Serra, Noemí; Rosales, Roser; Masana, Lluís; Vallvé, Joan-Carles

    2015-01-01

    The composition and structure of the extracellular matrix (ECM) in the vascular wall and in the atherosclerotic plaque are important factors that determine plaque stability. Statins can stabilize atherosclerotic plaques by modulating ECM protein expression. Fibulins are important components of the ECM. We evaluated the in vitro effect of simvastatin on the expression of fibulin-1, -2, -4 and -5 in human coronary artery smooth muscle cells (SMCs) and the mechanisms involved. Cells were incubated with simvastatin (0.05–1 μM), mevalonate (100 and 200 μM), geranylgeranyl pyrophosphate (GGPP) (15 μM), farnesyl pyrophosphate (FPP) (15 μM), the Rho kinase (ROCK) inhibitor Y-27632 (15 and 20 μM), the Rac-1 inhibitor (another member of Rho family) NSC23766 (100 μM), arachidonic acid (a RhoA/ROCK activator, 25–100 μM) and other fatty acids that are not activators of RhoA/ROCK (25–100 μM). Gene expression was analyzed by quantitative real-time PCR, and fibulin protein levels were analyzed by western blotting and ELISA. Simvastatin induced a significant increase in mRNA and protein levels of fibulin-2 at 24 hours of incubation (p<0.05), but it did not affect fibulin-1, -4, and -5 expression. Mevalonate and GGPP were able to reverse simvastatin’s effect, while FPP did not. In addition, Y-27632, but not NSC23766, significantly increased fibulin-2 expression. Furthermore, activation of the RhoA/ROCK pathway with arachidonic acid decreased fibulin-2 mRNA. Simvastatin increased mRNA levels and protein expression of the ECM protein fibulin-2 through a RhoA and Rho-Kinase-mediated pathway. This increase could affect the composition and structure of the ECM. PMID:26207907

  1. alpha-Hexachlorocyclohexane (alpha-HCH)

    Integrated Risk Information System (IRIS)

    alpha - Hexachlorocyclohexane ( alpha - HCH ) ; CASRN 319 - 84 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Ass

  2. The activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 to the distal CCAAT box of the RhoB promoter

    SciTech Connect

    Ahn, Jiwon; Choi, Jeong-Hae; Won, Misun; Kang, Chang-Mo; Gyun, Mi-Rang; Park, Hee-Moon; Kim, Chun-Ho; Chung, Kyung-Sook

    2011-06-03

    Highlights: {yields} Regulation of transcriptional activation of RhoB is still unclear. {yields} We examine the effect of p38 MAPK inhibition, and c-Jun and RhoB depletion on UV-induced RhoB expression and apoptosis. {yields} We identify the regions of RhoB promoter necessary to confer UV responsiveness using pRhoB-luciferase reporter assays. {yields} c-Jun, ATF2 and p300 are dominantly associated with NF-Y on the distal CCAAT box. {yields} The activation of p38 MAPK primarily contribute to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins on distal CCAAT box of RhoB promoter. -- Abstract: The Ras-related small GTP-binding protein RhoB is rapidly induced in response to genotoxic stresses caused by ionizing radiation. It is known that UV-induced RhoB expression results from the binding of activating transcription factor 2 (ATF2) via NF-Y to the inverted CCAAT box (-23) of the RhoB promoter. Here, we show that the association of c-Jun with the distal CCAAT box (-72) is primarily involved in UV-induced RhoB expression and p38 MAPK regulated RhoB induction through the distal CCAAT box. UV-induced RhoB expression and apoptosis were markedly attenuated by pretreatment with the p38 MAPK inhibitor. siRNA knockdown of RhoB, ATF2 and c-Jun resulted in decreased RhoB expression and eventually restored the growth of UV-irradiated Jurkat cells. In the reporter assay using luciferase under the RhoB promoter, inhibition of RhoB promoter activity by the p38 inhibitor and knockdown of c-Jun using siRNA occurred through the distal CCAAT box. Immunoprecipitation and DNA affinity protein binding assays revealed the association of c-Jun and p300 via NF-YA and the dissociation of histone deacetylase 1 (HDAC1) via c-Jun recruitment to the CCAAT boxes of the RhoB promoter. These results suggest that the activation of p38 MAPK primarily contributes to UV-induced RhoB expression by recruiting the c-Jun and p300 proteins to the distal CCAAT box of the RhoB promoter in

  3. RhoA activation promotes transendothelial migration of monocytes via ROCK.

    PubMed

    Honing, Henk; van den Berg, Timo K; van der Pol, Susanne M A; Dijkstra, Christine D; van der Kammen, Rob A; Collard, John G; de Vries, Helga E

    2004-03-01

    Monocyte infiltration into inflamed tissue requires the initial arrest of the cells on the endothelium followed by firm adhesion and their subsequent migration. Migration of monocytes and other leukocytes is believed to involve a coordinated remodeling of the actin cytoskeleton. The small GTPases RhoA, Rac1, and Cdc42 are critical regulators of actin reorganization. In this study, we have investigated the role of Rho-like GTPases RhoA, Rac1, and Cdc42 in the adhesion and migration of monocytes across brain endothelial cells by expressing their constitutively active or dominant-negative constructs in NR8383 rat monocytic cells. Monocytes expressing the active form of Cdc42 show a reduced migration, whereas Rac1 expression did not affect adhesion or migration. In contrast, expression of the active form of RhoA in monocytes leads to a dramatic increase in their adhesion and migration across endothelial cells. The effect of RhoA was found to be mediated by its down-stream effector Rho kinase (ROCK), as pretreatment with the selective ROCK inhibitor Y-27632 prevented this enhanced adhesion and migration. These results demonstrate that RhoA activation in monocytes is sufficient to enhance adhesion and migration across monolayers of endothelial cells. PMID:14634067

  4. Nitric oxide promotes epidermal stem cell migration via cGMP-Rho GTPase signalling

    PubMed Central

    Zhan, Rixing; He, Weifeng; Wang, Fan; Yao, Zhihui; Tan, Jianglin; Xu, Rui; Zhou, Junyi; Wang, Yuzhen; Li, Haisheng; Wu, Jun; LUO, Gaoxing

    2016-01-01

    The migration and reepithelization of epidermal stem cells (ESCs) are the most critical processes in wound healing. The gaseous messenger nitric oxide (NO) has multiple biological effects, but its actions on ESCs are poorly understood. In this study, an NO donor, S-nitroso-N-acetylpenicillamine (SNAP), was found to facilitate the in vitro migration of human ESCs (huESCs) in both live-imaging and scratch models. In addition, pull-down assays demonstrated that SNAP could activate the small GTPases RhoA and Rac1 of the Rho family, but not Cdc42. Moreover, the effects of SNAP on the migration and F-actin polymerization of ESCs could be blocked by inhibitors of cGMP, PKG, RhoA or Rac1, and by a specific siRNA of RhoA or Rac1, but not by a Cdc42 inhibitor or siRNA. Furthermore, the roles of NO in ESC migration via cGMP-Rho GTPase signalling in vivo were confirmed by tracing 5-bromo-2-deoxyuridine (BrdU)-labelled cells in a superficial, partial-thickness scald mouse model. Thus, the present study demonstrated that the NO donor SNAP could promote huESC migration in vitro. Furthermore, NO was found to induce ESC migration via cGMP-Rho GTPase RhoA and Rac1 signalling, but not Cdc42 signalling, both in vivo and in vitro. PMID:27469024

  5. An adventitious interaction of filamin A with RhoGDI2(Tyr153Glu).

    PubMed

    Song, Mia; He, Qianjing; Berk, Benjamin-Andreas; Hartwig, John H; Stossel, Thomas P; Nakamura, Fumihiko

    2016-01-15

    Filamin A (FLNA) is an actin filament crosslinking protein with multiple intracellular binding partners. Mechanical force exposes cryptic FLNA binding sites for some of these ligands. To identify new force-dependent binding interactions, we used a fusion construct composed of two FLNA domains, one of which was previously identified as containing a force-dependent binding site as a bait in a yeast two-hybrid system and identified the Rho dissociation inhibitor 2 (RhoGDI2) as a potential interacting partner. A RhoGDI2 truncate with 81 N-terminal amino acid residues and a phosphomimetic mutant, RhoGDI(Tyr153Glu) interacted with the FLNA construct. However, neither wild-type or full-length RhoGDI2 phosphorylated at Y153 interacted with FLNA. Our interpretation of these contradictions is that truncation and/or mutation of RhoGDI2 perturbs its conformation to expose a site that adventitiously binds FLNA and is not a bona-fide interaction. Therefore, previous studies reporting that a RhoGDI(Y153E) mutant suppresses the metastasis of human bladder cancer cells must be reinvestigated in light of artificial interaction of this point mutant with FLNA. PMID:26707877

  6. A novel role for RhoA GTPase in the regulation of airway smooth muscle contraction.

    PubMed

    Zhang, Wenwu; Huang, Youliang; Wu, Yidi; Gunst, Susan J

    2015-02-01

    Recent studies have demonstrated a novel molecular mechanism for the regulation of airway smooth muscle (ASM) contraction by RhoA GTPase. In ASM tissues, both myosin light chain (MLC) phosphorylation and actin polymerization are required for active tension generation. RhoA inactivation dramatically suppresses agonist-induced tension development and completely inhibits agonist-induced actin polymerization, but only slightly reduces MLC phosphorylation. The inhibition of MLC phosphatase does not reverse the effects of RhoA inactivation on contraction or actin polymerization. Thus, RhoA regulates ASM contraction through its effects on actin polymerization rather than MLC phosphorylation. Contractile stimulation of ASM induces the recruitment and assembly of paxillin, vinculin, and focal adhesion kinase (FAK) into membrane adhesion complexes (adhesomes) that regulate actin polymerization by catalyzing the activation of cdc42 GTPase by the G-protein-coupled receptor kinase-interacting target (GIT) - p21-activated kinase (PAK) - PAK-interacting exchange factor (PIX) complex. Cdc42 is a necessary and specific activator of the actin filament nucleation activator, N-WASp. The recruitment and activation of paxillin, vinculin, and FAK is prevented by RhoA inactivation, thus preventing cdc42 and N-WASp activation. We conclude that RhoA regulates ASM contraction by catalyzing the assembly and activation of membrane adhesome signaling modules that regulate actin polymerization, and that the RhoA-mediated assembly of adhesome complexes is a fundamental step in the signal transduction process in response to a contractile agonist. PMID:25531582

  7. Structural determinants of RGS-RhoGEF signaling critical to Entamoeba histolytica pathogenesis.

    PubMed

    Bosch, Dustin E; Kimple, Adam J; Manning, Alyssa J; Muller, Robin E; Willard, Francis S; Machius, Mischa; Rogers, Stephen L; Siderovski, David P

    2013-01-01

    G protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and guanosine triphosphatase-accelerating protein, EhRGS-RhoGEF, in a nucleotide state-selective fashion. Coexpression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the Dbl homology domain Rho-binding surface and the pleckstrin homology domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical "regulator of G protein signaling" domain rather than a RhoGEF-RGS ("rgRGS") domain, suggesting a convergent evolution toward heterotrimeric and small G protein cross-talk. PMID:23260656

  8. Structural Determinants of RGS-RhoGEF Signaling Critical to Entamoeba histolytica Pathogenesis

    PubMed Central

    Bosch, Dustin E.; Kimple, Adam J.; Manning, Alyssa J.; Muller, Robin E.; Willard, Francis S.; Machius, Mischa; Rogers, Stephen L.; Siderovski, David P.

    2012-01-01

    Summary G-protein signaling pathways, as key components of physiologic responsiveness and timing, are frequent targets for pharmacologic intervention. Here, we identify an effector for heterotrimeric G-protein α subunit (EhGα1) signaling from Entamoeba histolytica, the causative agent of amoebic colitis. EhGα1 interacts with this effector and GTPase-accelerating protein (GAP), EhRGS-RhoGEF, in a nucleotide state-selective fashion. Co-expression of EhRGS-RhoGEF with constitutively active EhGα1 and EhRacC leads to Rac-dependent spreading in Drosophila S2 cells. EhRGS-RhoGEF overexpression in E. histolytica trophozoites leads to reduced migration toward serum and lower cysteine protease activity, as well as reduced attachment to, and killing of, host cells. A 2.3 Å crystal structure of the full-length EhRGS-RhoGEF reveals a putative inhibitory helix engaging the DH domain Rho-binding surface and the PH domain. Mutational analysis of the EhGα1/EhRGS-RhoGEF interface confirms a canonical RGS domain rather than a RhoGEF-RGS (“rgRGS”) domain, suggesting a convergent evolution toward heterotrimeric and small G-protein cross-talk. PMID:23260656

  9. PAK4 promotes kinase-independent stabilization of RhoU to modulate cell adhesion

    PubMed Central

    Dart, Anna E.; Box, Gary M.; Court, William; Gale, Madeline E.; Brown, John P.; Pinder, Sarah E.; Eccles, Suzanne A.

    2015-01-01

    P21-activated kinase 4 (PAK4) is a Cdc42 effector protein thought to regulate cell adhesion disassembly in a kinase-dependent manner. We found that PAK4 expression is significantly higher in high-grade human breast cancer patient samples, whereas depletion of PAK4 modifies cell adhesion dynamics of breast cancer cells. Surprisingly, systematic analysis of PAK4 functionality revealed that PAK4-driven adhesion turnover is neither dependent on Cdc42 binding nor kinase activity. Rather, reduced expression of PAK4 leads to a concomitant loss of RhoU expression. We report that RhoU is targeted for ubiquitination by the Rab40A–Cullin 5 complex and demonstrate that PAK4 protects RhoU from ubiquitination in a kinase-independent manner. Overexpression of RhoU rescues the PAK4 depletion phenotype, whereas loss of RhoU expression reduces cell adhesion turnover and migration. These data support a new kinase-independent mechanism for PAK4 function, where an important role of PAK4 in cellular adhesions is to stabilize RhoU protein levels. Thus, PAK4 and RhoU cooperate to drive adhesion turnover and promote cell migration. PMID:26598620

  10. Thermal dileptons from {pi}-{rho} interactions in a hot pion gas

    SciTech Connect

    Baier, R.; Dirks, M.; Redlich, K. |

    1997-04-01

    The production of low mass dileptons from {pi}-{rho} interactions in a hot medium is studied. Applying finite temperature perturbation theory the dilepton rate is computed up to order g{sub {rho}}{sup 2}. For dilepton masses below the {rho} the two-body reactions {pi}{pi}{r_arrow}{rho}{gamma}{sup {asterisk}}, {pi}{rho}{r_arrow}{pi}{gamma}{sup {asterisk}}, and the decay process {rho}{r_arrow}{pi}{pi}{gamma}{sup {asterisk}} give significant contributions. Nonequilibrium contributions to the thermal rate are estimated, including the modification of the particle distribution function with a nonzero pion chemical potential. A comparison of the dilepton rate with the recent data measured in nucleus-nucleus collisions at CERN SPS energy by the CERES Collaboration is also performed. It is shown that the additional thermal dileptons from {pi}-{rho} interactions can partially account for the excess of the soft dilepton yield seen experimentally. {copyright} {ital 1997} {ital The American Physical Society}

  11. {pi}- and {rho}-mesons, and their diquark partners, from a contact interaction.

    SciTech Connect

    Roberts, H. L. L.; Bashir, A.; Gutierrez-Guerrero, L. X.; Roberts, C. D.; Wilson, D. J.

    2011-06-22

    We present a unified Dyson-Schwinger equation treatment of static and electromagnetic properties of pseudoscalar and vector mesons, and scalar and axial-vector diquark correlations, based upon a vector-vector contact interaction. A basic motivation for this paper is the need to document a comparison between the electromagnetic form factors of mesons and those diquarks that play a material role in nucleon structure. A notable result, therefore, is the large degree of similarity between related meson and diquark form factors. The simplicity of the interaction enables computation of the form factors at arbitrarily large spacelike Q{sup 2}, which enables us to expose a zero in the {rho}-meson electric form factor at z{sub Q}{sup {rho}} {approx} {radical}6m{sub {rho}}. Notably, r{sub {rho}}z{sub Q}{sup {rho}} {approx} r{sub D}z{sub Q}{sup D}, where r{sub {rho}} and r{sub D} are, respectively, the electric radii of the {rho}-meson and deuteron.

  12. {pi} and {rho} mesons, and their diquark partners, from a contact interaction

    SciTech Connect

    Roberts, H. L. L.; Bashir, A.; Gutierrez-Guerrero, L. X.; Roberts, C. D.; Wilson, D. J.

    2011-06-15

    We present a unified Dyson-Schwinger equation treatment of static and electromagnetic properties of pseudoscalar and vector mesons, and scalar and axial-vector diquark correlations, based upon a vector-vector contact interaction. A basic motivation for this paper is the need to document a comparison between the electromagnetic form factors of mesons and those diquarks that play a material role in nucleon structure. A notable result, therefore, is the large degree of similarity between related meson and diquark form factors. The simplicity of the interaction enables computation of the form factors at arbitrarily large spacelike Q{sup 2}, which enables us to expose a zero in the {rho}-meson electric form factor at z{sub Q}{sup {rho}}{approx_equal}{radical}6m{sub {rho}}. Notably, r{sub {rho}}zQ{sup {rho}}{approx_equal}r{sub D}z{sub Q}{sup D}, where r{sub {rho}} and r{sub D} are, respectively, the electric radii of the {rho}-meson and deuteron.

  13. Targeting of Rho Kinase Ameliorates Impairment of Diabetic Endothelial Function in Intrarenal Artery

    PubMed Central

    Yin, Hongping; Ru, Hailong; Yu, Liping; Kang, Yanhua; Lin, Guohua; Liu, Chuanfei; Sun, Lixian; Shi, Liyun; Sun, Qinghua; Liu, Cuiqing

    2013-01-01

    Endothelial dysfunction in kidney vasculature is the initial and key element for nephropathy in diabetes mellitus. Accumulating evidence suggests the protective role of Rho kinase inhibitors in endothelial dysfunction via modulating eNOS activity and NO production. However, the role of Rho kinase in diabetes-related endothelial dysfunction in kidney vasculature and the relevant mechanisms remain unknown. We assessed whether pharmacological inhibition of Rho kinase attenuates endothelial dysfunction in intrarenal arteries from type 1 diabetic rats. Fasudil, a Rho kinase inhibitor effectively decreased the phosphorylated level of MYPT1 without affecting the expression of ROCKs in the kidney. Fasudil treatment showed no improvement in diabetes-related abnormality in metabolic indices, but it significantly ameliorated endothelial dysfunction in intrarenal arteries and lessened the mesangial matrix expansion in the kidney cortex. Mechanistically, superoxide production in the intrarenal artery and NOX4 member of NADPH oxidase in the renal cortex that contribute to diabetic nephropathy were also prevented by the Rho kinase inhibitor. In conclusion, the present results indicate that Rho kinase is involved in endothelial dysfunction in type 1 diabetes via enhancement of oxidative stress and provides new evidence for Rho kinase inhibitors as potential therapeutic agents for the treatment of diabetic nephropathy. PMID:24129169

  14. Therapeutic effects of the Rho GTPase modulator CNF1 in a model of Parkinson's disease.

    PubMed

    Musilli, Marco; Ciotti, Maria Teresa; Pieri, Massimo; Martino, Assunta; Borrelli, Sonia; Dinallo, Vincenzo; Diana, Giovanni

    2016-10-01

    Recent evidence suggests an early involvement of dopaminergic (DA) processes and terminals in Parkinson's disease (PD). The arborization of neurons depends on the actin cytoskeleton, which in turn is regulated by small GTPases of the Rho family, encompassing Rho, Rac and Cdc42 subfamilies. Indeed, some reports point to a role for Rac and Cdc42 signaling in the pathophysiology of inherited parkinsonisms. We thus investigated the potential therapeutic effect of the modulation of cerebral Rho GTPases in PD. Cytotoxic necrotizing factor 1 (CNF1), a 114 kDa protein toxin produced by Escherichia coli, permanently activates RhoA, Rac1 and Cdc42 in intact cells. We report that the modulation of Rho GTPases by CNF1 results in hypertrophy of DA cell processes of cultured substantia nigra neurons, including increase in length, branching and varicosity. In vivo, the treatment corrects long-standing motor and biochemical asymmetries and restores degenerated nigrostriatal DA tissue after 6-hydroxydopamine lesion. We conclude that the pharmacological modulation of Rho GTPases shows neurorestorative potential and represents a promising avenue in the treatment PD. The study also suggests that naturally occurring molecules acting on Rho GTPase signaling, such as some bacterial protein toxins, might play a role in the development of PD. PMID:27350290

  15. Interactions of the Trichoderma reesei rho3 with the secretory pathway in yeast and T. reesei.

    PubMed

    Vasara, T; Salusjärvi, L; Raudaskoski, M; Keränen, S; Penttilä, M; Saloheimo, M

    2001-12-01

    We recently isolated from the filamentous fungus Trichoderma reesei (Hypocrea jecorina) a gene encoding RHOIII as a multicopy suppressor of the yeast temperature-sensitive secretory mutation, sec15-1. To characterize this gene further, we tested its ability to suppress other late-acting secretory mutations. The growth defect of yeast strains with sec1-1, sec1-11, sec3-2, sec6-4 and sec8-9 mutations was suppressed. Expression of rho3 also improved the impaired actin organization of sec15-1 cells at +38 degrees C. Overproduction of yeast Rho3p using the same expression vector as T. reesei RHOIII appeared to be toxic in sec3-101, sec5-24, sec8-9, sec10-2 and sec15-1 cells. When expressed from the GAL1 promoter, RHO3 suppressed the growth defect of sec1 at the restrictive temperature and inhibited the growth of sec3-101 at the permissive temperature. Disruption of the rho3 gene in the T. reesei genome did not affect the hyphal or colony morphology nor the cellular cytoskeleton organization. Furthermore, the growth of T. reesei was not affected on glucose by the rho3 disruption. Instead, both growth and protein secretion of T. reesei in cellulose cultures was remarkably decreased in rho3 disruptant strains when compared with the parental strain. These results suggest that rho3 is involved in secretion processes in T. reesei. PMID:11886564

  16. The Bacterial Transcription Termination Factor Rho Coordinates Mg(2+) Homeostasis with Translational Signals.

    PubMed

    Kriner, Michelle A; Groisman, Eduardo A

    2015-12-01

    The bacterial protein Rho triggers transcription termination at the ends of many operons and when transcription and translation become uncoupled. In addition to these genome wide activities, Rho implements regulation of specific genes by dictating whether RNA polymerase terminates transcription within the 5' leader region or continues into the downstream coding region. Here, we report that the Mg(2+) channel gene corA in Salmonella enterica serovar Typhimurium, which was previously thought to be constitutively expressed, is regulated by a Rho-dependent terminator located within its 5' leader region. We demonstrate that the unusually long and highly conserved corA leader mRNA can adopt two mutually exclusive conformations that determine whether or not Rho interacts with a Rho utilization site on the nascent RNA and thereby prevents transcription of the corA coding region. The RNA conformation that promotes Rho-dependent termination is favored by efficient translation of corL, a short open reading frame located within the corA leader. Thus, corA transcription is inversely coupled to corL translation. This mechanism resembles those governing expression of Salmonella's other two Mg(2+) transport genes, suggesting that Rho links Mg(2+) uptake to translational signals. PMID:26523680

  17. Binding and Translocation of Termination Factor Rho Studied at the Single-Molecule Level

    PubMed Central

    Koslover, Daniel J.; Fazal, Furqan M.; Mooney, Rachel A.; Landick, Robert; Block, Steven M.

    2012-01-01

    Rho termination factor is an essential hexameric helicase responsible for terminating 20–50% of all mRNA synthesis in E. coli. We used single- molecule force spectroscopy to investigate Rho-RNA binding interactions at the Rho- utilization (rut) site of the ? tR1 terminator. Our results are consistent with Rho complexes adopting two states, one that binds 57 ±2 nucleotides of RNA across all six of the Rho primary binding sites, and another that binds 85 ±2 nucleotides at the six primary sites plus a single secondary site situated at the center of the hexamer. The single-molecule data serve to establish that Rho translocates 5′-to-3′ towards RNA polymerase (RNAP) by a tethered-tracking mechanism, looping out the intervening RNA between the rut site and RNAP. These findings lead to a general model for Rho binding and translocation, and establish a novel experimental approach that should facilitate additional single- molecule studies of RNA-binding proteins. PMID:22885804

  18. Simvastatin Attenuates Neuropathic Pain by Inhibiting the RhoA/LIMK/Cofilin Pathway.

    PubMed

    Qiu, Y; Chen, W Y; Wang, Z Y; Liu, F; Wei, M; Ma, C; Huang, Y G

    2016-09-01

    Neuropathic pain occurs due to deleterious changes in the nervous system caused by a lesion or dysfunction. Currently, neuropathic pain management is unsatisfactory and remains a challenge in clinical practice. Studies have suggested that actin cytoskeleton remodeling may be associated with neural plasticity and may involve a nociceptive mechanism. Here, we found that the RhoA/LIM kinase (LIMK)/cofilin pathway, which regulates actin dynamics, was activated after chronic constriction injury (CCI) of the sciatic nerve. Treatments that reduced RhoA/LIMK/cofilin pathway activity, including simvastatin, the Rho kinase inhibitor Y-27632, and the synthetic peptide Tat-S3, attenuated actin filament disruption in the dorsal root ganglion and CCI-induced neuropathic pain. Over-activation of the cytoskeleton caused by RhoA/LIMK/cofilin pathway activation may produce a scaffold for the trafficking of nociceptive signaling factors, leading to chronic neuropathic pain. Here, we found that simvastatin significantly decreased the ratio of membrane/cytosolic RhoA, which was significantly increased after CCI, by inhibiting the RhoA/LIMK/cofilin pathway. This effect was highly dependent on the function of the cytoskeleton as a scaffold for signal trafficking. We conclude that simvastatin attenuated neuropathic pain in rats subjected to CCI by inhibiting actin-mediated intracellular trafficking to suppress RhoA/LIMK/cofilin pathway activity. PMID:27216618

  19. Redundancy of primary RNA-binding functions of the bacterial transcription terminator Rho

    PubMed Central

    Shashni, Rajesh; Qayyum, M. Zuhaib; Vishalini, V.; Dey, Debashish; Sen, Ranjan

    2014-01-01

    The bacterial transcription terminator, Rho, terminates transcription at half of the operons. According to the classical model derived from in vitro assays on a few terminators, Rho is recruited to the transcription elongation complex (EC) by recognizing specific sites (rut) on the nascent RNA. Here, we explored the mode of in vivo recruitment process of Rho. We show that sequence specific recognition of the rut site, in majority of the Rho-dependent terminators, can be compromised to a great extent without seriously affecting the genome-wide termination function as well as the viability of Escherichia coli. These terminators function optimally only through a NusG-assisted recruitment and activation of Rho. Our data also indicate that at these terminators, Rho-EC-bound NusG interaction facilitates the isomerization of Rho into a translocase-competent form by stabilizing the interactions of mRNA with the secondary RNA binding site, thereby overcoming the defects of the primary RNA binding functions. PMID:25081210

  20. THE INITIAL MASS FUNCTION AND DISK FREQUENCY OF THE {rho} OPHIUCHI CLOUD: AN EXTINCTION-LIMITED SAMPLE

    SciTech Connect

    Erickson, Kristen L.; Wilking, Bruce A.; Robinson, John G.; Stephenson, Lauren N.; Meyer, Michael R. E-mail: bwilking@umsl.edu E-mail: lnafff@mail.umsl.edu

    2011-10-15

    We have completed an optical spectroscopic survey of an unbiased, extinction-limited sample of candidate young stars covering 1.3 deg{sup 2} of the {rho} Ophiuchi star-forming region. While infrared, X-ray, and optical surveys of the cloud have identified many young stellar objects (YSOs), these surveys are biased toward particular stages of stellar evolution and are not optimal for studies of the disk frequency and initial mass function. We have obtained over 300 optical spectra to help identify 135 association members based on the presence of H{alpha} in emission, lithium absorption, X-ray emission, a mid-infrared excess, a common proper motion, reflection nebulosity, and/or extinction considerations. Spectral types along with R- and I-band photometry were used to derive effective temperatures and bolometric luminosities for association members to compare with theoretical tracks and isochrones for pre-main-sequence stars. An average age of 3.1 Myr is derived for this population which is intermediate between that of objects embedded in the cloud core of {rho} Ophiuchi and low-mass stars in the Upper Scorpius subgroup. Consistent with this age we find a circumstellar disk frequency of 27% {+-} 5%. We also constructed an initial mass function for an extinction-limited sample of 123 YSOs (A{sub v} {<=} 8 mag), which is consistent with the field star initial mass function for YSOs with masses >0.2 M{sub sun}. There may be a deficit of brown dwarfs but this result relies on completeness corrections and requires confirmation.

  1. Alpha-1 Antitrypsin Test

    MedlinePlus

    ... measures the level of the protein AAT in blood. Alpha-1 antitrypsin phenotype testing evaluates the amount and type of AAT being produced and compares it to normal patterns. Alpha-1 antitrypsin genotype testing ( DNA testing) can ...

  2. Alpha-1 antitrypsin test

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/003715.htm Alpha-1 antitrypsin test To use the sharing features on this page, please enable JavaScript. Alpha-1 antitrypsin is a laboratory test to measure the ...

  3. Lipopolysaccharide-induced Lung Injury Involves the Nitration-mediated Activation of RhoA*

    PubMed Central

    Rafikov, Ruslan; Dimitropoulou, Christiana; Aggarwal, Saurabh; Kangath, Archana; Gross, Christine; Pardo, Daniel; Sharma, Shruti; Jezierska-Drutel, Agnieszka; Patel, Vijay; Snead, Connie; Lucas, Rudolf; Verin, Alexander; Fulton, David; Catravas, John D.; Black, Stephen M.

    2014-01-01

    Acute lung injury (ALI) is characterized by increased endothelial hyperpermeability. Protein nitration is involved in the endothelial barrier dysfunction in LPS-exposed mice. However, the nitrated proteins involved in this process have not been identified. The activation of the small GTPase RhoA is a critical event in the barrier disruption associated with LPS. Thus, in this study we evaluated the possible role of RhoA nitration in this process. Mass spectroscopy identified a single nitration site, located at Tyr34 in RhoA. Tyr34 is located within the switch I region adjacent to the nucleotide-binding site. Utilizing this structure, we developed a peptide designated NipR1 (nitration inhibitory peptide for RhoA 1) to shield Tyr34 against nitration. TAT-fused NipR1 attenuated RhoA nitration and barrier disruption in LPS-challenged human lung microvascular endothelial cells. Further, treatment of mice with NipR1 attenuated vessel leakage and inflammatory cell infiltration and preserved lung function in a mouse model of ALI. Molecular dynamics simulations suggested that the mechanism by which Tyr34 nitration stimulates RhoA activity was through a decrease in GDP binding to the protein caused by a conformational change within a region of Switch I, mimicking the conformational shift observed when RhoA is bound to a guanine nucleotide exchange factor. Stopped flow kinetic analysis was used to confirm this prediction. Thus, we have identified a new mechanism of nitration-mediated RhoA activation involved in LPS-mediated endothelial barrier dysfunction and show the potential utility of “shielding” peptides to prevent RhoA nitration in the management of ALI. PMID:24398689

  4. Rho guanine nucleotide exchange factors involved in cyclic-stretch-induced reorientation of vascular endothelial cells.

    PubMed

    Abiko, Hiyori; Fujiwara, Sachiko; Ohashi, Kazumasa; Hiatari, Ryuichi; Mashiko, Toshiya; Sakamoto, Naoya; Sato, Masaaki; Mizuno, Kensaku

    2015-05-01

    Cyclic stretch is an artificial model of mechanical force loading, which induces the reorientation of vascular endothelial cells and their stress fibers in a direction perpendicular to the stretch axis. Rho family GTPases are crucial for cyclic-stretch-induced endothelial cell reorientation; however, the mechanism underlying stretch-induced activation of Rho family GTPases is unknown. A screen of short hairpin RNAs targeting 63 Rho guanine nucleotide exchange factors (Rho-GEFs) revealed that at least 11 Rho-GEFs – Abr, alsin, ARHGEF10, Bcr, GEF-H1 (also known as ARHGEF2), LARG (also known as ARHGEF12), p190RhoGEF (also known as ARHGEF28), PLEKHG1, P-REX2, Solo (also known as ARHGEF40) and α-PIX (also known as ARHGEF6) – which specifically or broadly target RhoA, Rac1 and/or Cdc42, are involved in cyclic-stretch-induced perpendicular reorientation of endothelial cells. Overexpression of Solo induced RhoA activation and F-actin accumulation at cell-cell and cell-substrate adhesion sites. Knockdown of Solo suppressed cyclic-stretch- or tensile-force-induced RhoA activation. Moreover, knockdown of Solo significantly reduced cyclic-stretch-induced perpendicular reorientation of endothelial cells when cells were cultured at high density, but not when they were cultured at low density or pretreated with EGTA or VE-cadherin-targeting small interfering RNAs. These results suggest that Solo is involved in cell-cell-adhesion-mediated mechanical signal transduction during cyclic-stretch-induced endothelial cell reorientation. PMID:25795300

  5. Detection and Quantification of ADP-Ribosylated RhoA/B by Monoclonal Antibody

    PubMed Central

    Rohrbeck, Astrid; Fühner, Viola; Schröder, Anke; Hagemann, Sandra; Vu, Xuan-Khang; Berndt, Sarah; Hust, Michael; Pich, Andreas; Just, Ingo

    2016-01-01

    Clostridium botulinum exoenzyme C3 is the prototype of C3-like ADP-ribosyltransferases that modify the GTPases RhoA, B, and C. C3 catalyzes the transfer of an ADP-ribose moiety from the co-substrate nicotinamide adenine dinucleotide (NAD) to asparagine-41 of Rho-GTPases. Although C3 does not possess cell-binding/-translocation domains, C3 is able to efficiently enter intact cells, including neuronal and macrophage-like cells. Conventionally, the detection of C3 uptake into cells is carried out via the gel-shift assay of modified RhoA. Since this gel-shift assay does not always provide clear, evaluable results an additional method to confirm the ADP-ribosylation of RhoA is necessary. Therefore, a new monoclonal antibody has been generated that specifically detects ADP-ribosylated RhoA/B, but not RhoC, in Western blot and immunohistochemical assay. The scFv antibody fragment was selected by phage display using the human naive antibody gene libraries HAL9/10. Subsequently, the antibody was produced as scFv-Fc and was found to be as sensitive as a commercially available RhoA antibody providing reproducible and specific results. We demonstrate that this specific antibody can be successfully applied for the analysis of ADP-ribosylated RhoA/B in C3-treated Chinese hamster ovary (CHO) and HT22 cells. Moreover, ADP-ribosylation of RhoA was detected within 10 min in C3-treated CHO wild-type cells, indicative of C3 cell entry. PMID:27043630

  6. Detection and Quantification of ADP-Ribosylated RhoA/B by Monoclonal Antibody.

    PubMed

    Rohrbeck, Astrid; Fühner, Viola; Schröder, Anke; Hagemann, Sandra; Vu, Xuan-Khang; Berndt, Sarah; Hust, Michael; Pich, Andreas; Just, Ingo

    2016-04-01

    Clostridium botulinum exoenzyme C3 is the prototype of C3-like ADP-ribosyltransferases that modify the GTPases RhoA, B, and C. C3 catalyzes the transfer of an ADP-ribose moiety from the co-substrate nicotinamide adenine dinucleotide (NAD) to asparagine-41 of Rho-GTPases. Although C3 does not possess cell-binding/-translocation domains, C3 is able to efficiently enter intact cells, including neuronal and macrophage-like cells. Conventionally, the detection of C3 uptake into cells is carried out via the gel-shift assay of modified RhoA. Since this gel-shift assay does not always provide clear, evaluable results an additional method to confirm the ADP-ribosylation of RhoA is necessary. Therefore, a new monoclonal antibody has been generated that specifically detects ADP-ribosylated RhoA/B, but not RhoC, in Western blot and immunohistochemical assay. The scFv antibody fragment was selected by phage display using the human naive antibody gene libraries HAL9/10. Subsequently, the antibody was produced as scFv-Fc and was found to be as sensitive as a commercially available RhoA antibody providing reproducible and specific results. We demonstrate that this specific antibody can be successfully applied for the analysis of ADP-ribosylated RhoA/B in C3-treated Chinese hamster ovary (CHO) and HT22 cells. Moreover, ADP-ribosylation of RhoA was detected within 10 min in C3-treated CHO wild-type cells, indicative of C3 cell entry. PMID:27043630

  7. Rho Kinase Pathway Alterations in the Brain and Leukocytes in Huntington's Disease.

    PubMed

    Narayanan, K Lakshmi; Chopra, Vanita; Rosas, H Diana; Malarick, Keith; Hersch, Steven

    2016-05-01

    Huntington's disease (HD) is a fatal neurodegenerative disease caused by an expanded polyglutamine tract in the huntingtin gene. Therapeutic approaches targeting mutant huntingtin (mtHtt) or its downstream toxic consequences are under development, including Rho kinase pathway inhibition. We investigated the messenger RNA (mRNA) expression of Rho kinase pathway genes, including RhoA (Ras homolog family member A), ROCK1 (Rho-associated kinase1), PRK2 (protein kinase C-related protein kinase 2), Profilin1, cofilin1, MYPT1 (myosin phosphatase target subunit 1), and LIMK1 (LIM domain kinase 1) in HD human blood leukocytes, postmortem brain, and in R6/2 HD mouse brain tissue using qPCR. RhoA, ROCK1, PRK2, Profilin1, cofilin1, and MYPT1 were significantly increased in HD blood compared to controls. In frontal cortex of HD postmortem brain tissue, the expression of RhoA, ROCK1, PRK2, Profilin1, and MYPT1 were also significantly increased. In the brain from 4-week-old R6/2 mice, the expression of Rock1, Prk2, Cofilin1, and MYPT1 was significantly increased while RhoA, Rock1, Profilin1, Cofilin1, and Mypt1 were increased and Limk1 mRNA decreased in 13-week-old R6/2 mice. Western blot analysis using human postmortem tissues for ROCK1 and Profilin1 demonstrated significantly increased protein levels, which correlated with the mRNA increases. Collectively, we have shown the panel of Rho kinase pathway genes to be highly altered in human HD blood, postmortem brain tissue, and in R6/2 mice. These studies confirm that HD upregulates the Rho kinase pathway and identifies mRNAs that could serve as peripheral markers in HD patients and translational markers in HD mouse models. PMID:25941073

  8. Control of postnatal apoptosis in the neocortex by RhoA-subfamily GTPases determines neuronal density.

    PubMed

    Sanno, Hitomi; Shen, Xiao; Kuru, Nilgün; Bormuth, Ingo; Bobsin, Kristin; Gardner, Humphrey A R; Komljenovic, Dorde; Tarabykin, Victor; Erzurumlu, Reha S; Tucker, Kerry L

    2010-03-24

    Apoptosis of neurons in the maturing neocortex has been recorded in a wide variety of mammals, but very little is known about its effects on cortical differentiation. Recent research has implicated the RhoA GTPase subfamily in the control of apoptosis in the developing nervous system and in other tissue types. Rho GTPases are important components of the signaling pathways linking extracellular signals to the cytoskeleton. To investigate the role of the RhoA GTPase subfamily in neocortical apoptosis and differentiation, we have engineered a mouse line in which a dominant-negative RhoA mutant (N19-RhoA) is expressed from the Mapt locus, such that all neurons of the developing nervous system are expressing the N19-RhoA inhibitor. Postnatal expression of N19-RhoA led to no major changes in neocortical anatomy. Six layers of the neocortex developed and barrels (whisker-related neural modules) formed in layer IV. However, the density and absolute number of neurons in the somatosensory cortex increased by 12-26% compared with wild-type littermates. This was not explained by a change in the migration of neurons during the formation of cortical layers but rather by a large decrease in the amount of neuronal apoptosis at postnatal day 5, the developmental maximum of cortical apoptosis. In addition, overexpression of RhoA in cortical neurons was seen to cause high levels of apoptosis. These results demonstrate that RhoA-subfamily members play a major role in developmental apoptosis in postnatal neocortex of the mouse but that decreased apoptosis does not alter cortical cytoarchitecture and patterning. PMID:20335457

  9. Control of postnatal apoptosis in the neocortex by RhoA-subfamily GTPases determines neuronal density

    PubMed Central

    Sanno, Hitomi; Shen, Xiao; Kuru, Nilgün; Bormuth, Ingo; Bobsin, Kristin; Komljenovic, Dorde; Tarabykin, Victor; Erzurumlu, Reha S.; Tucker, Kerry L.

    2010-01-01

    Apoptosis of neurons in the maturing neocortex has been recorded in a wide variety of mammals, but very little is known about its effects on cortical differentiation. Recent research has implicated the RhoA GTPase subfamily in the control of apoptosis in the developing nervous system and in other tissue types. Rho GTPases are important components of the signaling pathways linking extracellular signals to the cytoskeleton. To investigate the role of the RhoA GTPase subfamily in neocortical apoptosis and differentiation, we have engineered a mouse line in which a dominant-negative RhoA mutant (N19-RhoA) is expressed from the Mapt locus, such that all neurons of the developing nervous system are expressing the N19-RhoA inhibitor. Postnatal expression of N19-RhoA led to no major changes in neocortical anatomy. Six layers of the neocortex developed and barrels (whisker-related neural modules) formed in layer IV. However, the density and absolute number of neurons in the somatosensory cortex increased by 12 - 26%, as compared to wildtype littermates. This was not explained by a change in the migration of neurons during the formation of cortical layers, but rather by a large decrease in the amount of neuronal apoptosis at P5, the developmental maximum of cortical apoptosis. In addition, overexpression of RhoA in cortical neurons was seen to cause high levels of apoptosis. These results demonstrate that RhoA-subfamily members play a major role in developmental apoptosis in postnatal neocortex of the mouse, but that decreased apoptosis does not alter cortical cytoarchitecture and patterning. PMID:20335457

  10. Arachidonic acid induction of Rho-mediated transendothelial migration in prostate cancer

    PubMed Central

    Brown, M; Roulson, J-A; Hart, C A; Tawadros, T; Clarke, N W

    2014-01-01

    Background: Bone metastases in prostate cancer (CaP) result in CaP-related morbidity/mortality. The omega-6 polyunsaturated fatty acid (PUFA) arachidonic acid (AA) and lipophilic statins affect metastasis-like behaviour in CaP cells, regulating the critical metastatic step of CaP migration to the bone marrow stroma. Methods: Microscopic analysis and measurement of adhesion and invasion of CaP cells through bone marrow endothelial cells (BMEC) was undertaken with AA stimulation and/or simvastatin (SIM) treatment. Amoeboid characteristics of PC-3, PC3-GFP and DU-145 were analysed by western blotting and Rho assays. Results: The CaP cell lines PC-3, PC3-GFP and DU-145 share the ability to migrate across a BMEC layer. Specific amoeboid inhibition decreased transendothelial migration (TEM). AA stimulates amoeboid characteristics, driven by Rho signalling. Selective knock-down of components of the Rho pathway (RhoA, RhoC, Rho-associated protein kinase 1 (ROCK1) and ROCK2) showed that Rho signalling is crucial to TEM. Functions of these components were analysed, regarding adhesion to BMEC, migration in 2D and the induction of the amoeboid phenotype by AA. TEM was reduced by SIM treatment of PC3-GFP and DU-145, which inhibited Rho pathway signalling. Conclusions: AA-induced TEM is mediated by the induction of a Rho-driven amoeboid phenotype. Inhibition of this cell migratory process may be an important therapeutic target in high-risk CaP. PMID:24595005

  11. Nuclear RhoA signaling regulates MRTF-dependent SMC-specific transcription

    PubMed Central

    Staus, Dean P.; Weise-Cross, Laura; Mangum, Kevin D.; Medlin, Matt D.; Mangiante, Lee; Taylor, Joan M.

    2014-01-01

    We have previously shown that RhoA-mediated actin polymerization stimulates smooth muscle cell (SMC)-specific transcription by regulating the nuclear localization of the myocardin-related transcription factors (MRTFs). On the basis of the recent demonstration that nuclear G-actin regulates MRTF nuclear export and observations from our laboratory and others that the RhoA effector, mDia2, shuttles between the nucleus and cytoplasm, we investigated whether nuclear RhoA signaling plays a role in regulating MRTF activity. We identified sequences that control mDia2 nuclear-cytoplasmic shuttling and used mDia2 variants to demonstrate that the ability of mDia2 to fully stimulate MRTF nuclear accumulation and SMC-specific gene transcription was dependent on its localization to the nucleus. To test whether RhoA signaling promotes nuclear actin polymerization, we established a fluorescence recovery after photobleaching (FRAP)-based assay to measure green fluorescent protein-actin diffusion in the nuclear compartment. Nuclear actin FRAP was delayed in cells expressing nuclear-targeted constitutively active mDia1 and mDia2 variants and in cells treated with the polymerization inducer, jasplakinolide. In contrast, FRAP was enhanced in cells expressing a nuclear-targeted variant of mDia that inhibits both mDia1 and mDia2. Treatment of 10T1/2 cells with sphingosine 1-phosphate induced RhoA activity in the nucleus and forced nuclear localization of RhoA or the Rho-specific guanine nucleotide exchange factor (GEF), leukemia-associated RhoGEF, enhanced the ability of these proteins to stimulate MRTF activity. Taken together, these data support the emerging idea that RhoA-dependent nuclear actin polymerization has important effects on transcription and nuclear structure. PMID:24906914

  12. Activation of Rho-kinase in the brainstem enhances sympathetic drive in mice with heart failure.

    PubMed

    Ito, Koji; Kimura, Yoshikuni; Hirooka, Yoshitaka; Sagara, Yoji; Sunagawa, Kenji

    2008-11-01

    Rho-kinase is involved in the pathogenesis of hypertension and left ventricular remodelling after myocardial infarction (MI). In an earlier study, we had demonstrated that Rho-kinase in the brainstem contributes to hypertensive mechanisms via the sympathetic nervous system; however, it is not known whether Rho-kinase in the brainstem also contributes to sympathetic nerve activation after MI. Male Institute of Cancer Research mice (8-10 weeks old) were used for the study. Two days before coronary artery occlusion (MI group), the left ventricular function was estimated by echocardiography. Following this, Y-27632 (0.5 mM, 0.25 microL/h), a specific Rho-kinase inhibitor, or a vehicle was intracisternally infused in the mice using an osmotic mini-pump. Nine days after coronary artery occlusion, we evaluated the 24-hour urinary norepinephrine excretion (U-NE) as a marker of sympathetic nerve activity. Ten days after coronary artery occlusion, we measured organ weight and evaluated Rho-kinase activity in the brainstem by measuring the amount of phosphorylated ezrin/radixin/moesin proteins, one of the substrates of Rho-kinase. The control group underwent a sham operation. Rho-kinase activity, U-NE, and lungs and liver weight were significantly greater in the MI group compared with the control group. Left ventricular size increased and percent fractional shortening decreased in the MI group compared with the control group. Y-27632 significantly decreased Rho-kinase activity and attenuated the increase in U-NE after MI. These results demonstrate that Rho-kinase is activated in the brainstem after MI and that the activation of this pathway is involved in the resulting enhanced sympathetic drive. PMID:18762460

  13. Engineering and expression of a RhoA peptide against respiratory syncytial virus infection in plants.

    PubMed

    Ortega-Berlanga, Benita; Musiychuk, Konstantin; Shoji, Yoko; Chichester, Jessica A; Yusibov, Vidadi; Patiño-Rodríguez, Omar; Noyola, Daniel E; Alpuche-Solís, Ángel G

    2016-02-01

    MAIN CONCLUSION : A RhoA-derived peptide fused to carrier molecules from plants showed enhanced biological activity of in vitro assays against respiratory syncytial virus compared to the RhoA peptide alone or the synthetic RhoA peptide. A RhoA-derived peptide has been reported for over a decade as a potential inhibitor of respiratory syncytial virus (RSV) infection both in vitro and in vivo and is anticipated to be a promising alternative to monoclonal antibody-based therapy against RSV infection. However, there are several challenges to furthering development of this antiviral peptide, including improvement in the peptide’s bioavailability, development of an efficient delivery system and identification of a cost-effective production platform. In this study, we have engineered a RhoA peptide as a genetic fusion to two carrier molecules, either lichenase (LicKM) or the coat protein (CP) of Alfalfa mosaic virus. These constructs were introduced into Nicotiana benthamiana plants using a tobacco mosaic virus-based expression vector and targets purified. The results demonstrated that the RhoA peptide fusion proteins were efficiently expressed in N. benthamiana plants, and that two of the resulting fusion proteins, RhoA-LicKM and RhoA2-FL-d25CP, inhibited RSV growth in vitro by 50 and 80 %, respectively. These data indicate the feasibility of transient expression of this biologically active antiviral RhoA peptide in plants and the advantage of using a carrier molecule to enhance target expression and efficacy. PMID:26474991

  14. The role of the Rho/ROCK signaling pathway in inhibiting axonal regeneration in the central nervous system.

    PubMed

    Liu, Jing; Gao, Hong-Yan; Wang, Xiao-Feng

    2015-11-01

    The Rho/Rho-associated coiled-coil containing protein kinase (Rho/ROCK) pathway is a major signaling pathway in the central nervous system, transducing inhibitory signals to block regeneration. After central nervous system damage, the main cause of impaired regeneration is the presence of factors that strongly inhibit regeneration in the surrounding microenvironment. These factors signal through the Rho/ROCK signaling pathway to inhibit regeneration. Therefore, a thorough understanding of the Rho/ROCK signaling pathway is crucial for advancing studies on regeneration and repair of the injured central nervous system. PMID:26807132

  15. The role of the Rho/ROCK signaling pathway in inhibiting axonal regeneration in the central nervous system

    PubMed Central

    Liu, Jing; Gao, Hong-yan; Wang, Xiao-feng

    2015-01-01

    The Rho/Rho-associated coiled-coil containing protein kinase (Rho/ROCK) pathway is a major signaling pathway in the central nervous system, transducing inhibitory signals to block regeneration. After central nervous system damage, the main cause of impaired regeneration is the presence of factors that strongly inhibit regeneration in the surrounding microenvironment. These factors signal through the Rho/ROCK signaling pathway to inhibit regeneration. Therefore, a thorough understanding of the Rho/ROCK signaling pathway is crucial for advancing studies on regeneration and repair of the injured central nervous system. PMID:26807132

  16. A study of the nuclear-medium influence on {rho}{sup 0} neutrinoproduction

    SciTech Connect

    Agababyan, N. M.; Ammosov, V. V.; Atayan, M.; Grigoryan, N.; Gulkanyan, H.; Ivanilov, A.A.; Karamyan, Zh.; Korotkov, V. A.

    2007-11-15

    The nuclear effects in {rho}{sup 0}-meson neutrino production are investigated using the data obtained with the SKAT bubble chamber. The nuclear-medium influence on the {rho}{sup 0} total yield and inclusive distributions on z = E{sub {rho}/}v and Feynman x{sub F} variable is found to be approximately the same as for pions. It is shown that these distributions with increasing A tend to shift toward smaller values of z and x{sub F}, thus indicating an increasing role of secondary intranuclear interactions. The predictions of a simple model incorporating the latter are found to be in qualitative agreement with experimental data.

  17. Spin Density Matrix Elements from {rho}{sup 0} and {phi} Meson Electroproduction at HERMES

    SciTech Connect

    Borissov, A.

    2009-03-23

    Exclusive production of {rho}{sup 0} and {phi} mesons on hydrogen and deuterium targets is studied in the HERMES kinematic region 1rho}{sup 0}, but not for {phi}. In exclusive {rho}{sup 0} production on the proton an indication is observed of a contribution of unnatural-parity exchange amplitudes, for which the dependence on Q{sup 2} and t' is shown.

  18. Drosophila RhoGEF4 encodes a novel RhoA-specific guanine exchange factor that is highly expressed in the embryonic central nervous system.

    PubMed

    Nahm, Minyeop; Lee, Mihye; Baek, Seung-Hak; Yoon, Jin-Ho; Kim, Hong-Hee; Lee, Zang Hee; Lee, Seungbok

    2006-12-15

    Rho family small GTPases act as molecular switches that regulate neuronal morphogenesis, including axon growth and guidance, dendritic spine formation, and synapse formation. These proteins are positively regulated by guanine nucleotide exchange factors (GEFs) of the Dbl family. This study describes the identification and characterization of Drosophila RhoGEF4 (DRhoGEF4), a novel Dbl family protein that is specifically expressed in the central nervous system during Drosophila embryogenesis. The predicted amino acid sequence of DRhoGEF4 contains a Dbl homology (DH) domain and an adjacent C-terminal pleckstrin homology (PH) domain, which are most closely related to those of mammalian frabins. In this study, the DH-PH motif is shown to enhance the dissociation of GDP from either RhoA or Rac1 but not from Cdc42 in vitro. In addition, p21-binding domain pull-down assays demonstrate that DRhoGEF4 activates RhoA, but neither Rac1 nor Cdc42 in HEK293 cells. Finally, overexpression of DRhoGEF4 is able to induce assembly of stress fibers in cultured NIH3T3 cells. Taken together, these findings suggest that DRhoGEF4 may participate in cytoskeleton-related cellular events by specifically activating RhoA in neuronal morphogenesis. PMID:17011730

  19. Branching Fraction Measurements of B+ to rho+ gamma,B0 to rho0 gamma, and B0 to omega gamma

    SciTech Connect

    Aubert, B.

    2007-01-03

    The authors present a study of the decays B{sup +} {yields} {rho}{sup +}{gamma}, B{sup 0} {yields} {rho}{sup 0}{gamma}, and B{sup 0} {yields} {omega}{gamma}. The analysis is based on data containing 347 million B{bar B} events recorded with the BABAR detector at the PEP-II asymmetric B factory. They measure the branching fractions {Beta}(B{sup +} {yields} {rho}{sup +}{gamma}) = (1.10{sub -0.33}{sup +0.37} {+-} 0.09) x 10{sup -6} and {Beta}(B{sup 0} {yields} {rho}{sup 0}{gamma}) = (0.79{sub -0.20}{sup +0.22} {+-} 0.06) x 10{sup -6}, and set a 90% C.L. upper limit {Beta}(B{sup 0} {yields} {omega}{gamma}) < 0.78 x 10{sup -6}. They also measure the isospin-averaged branching fraction {Beta}[B {yields} ({rho}/{omega}){gamma}] = (1.25{sub -0.24}{sup +0.25} {+-} 0.09) x 10{sup -6}, from which they determine |V{sub td}/V{sub ts}| = 0.200{sub -0.020}{sup +0.021} {+-} 0.015, where the first uncertainty is experimental and the second is theoretical.

  20. The Alpha Centauri System.

    ERIC Educational Resources Information Center

    Soderblom, David R.

    1987-01-01

    Describes the Alpha Centauri star system, which is the closest star system to the sun. Discusses the difficulties associated with measurements involving Alpha Centauri, along with some of the recent advances in stellar seismology. Raises questions about the possibilities of planets around Alpha Centauri. (TW)

  1. Inhibition of the RhoA GTPase Activity Increases Sensitivity of Melanoma Cells to UV Radiation Effects

    PubMed Central

    Espinha, Gisele; Osaki, Juliana Harumi; Costa, Erico Tosoni; Forti, Fabio Luis

    2016-01-01

    Ultraviolet radiation is the main cause of DNA damage to melanocytes and development of melanoma, one of the most lethal human cancers, which leads to metastasis due to uncontrolled cell proliferation and migration. These phenotypes are mediated by RhoA, a GTPase overexpressed or overactivated in highly aggressive metastatic tumors that plays regulatory roles in cell cycle progression and cytoskeleton remodeling. This work explores whether the effects of UV on DNA damage, motility, proliferation, and survival of human metastatic melanoma cells are mediated by the RhoA pathway. Mutant cells expressing dominant-negative (MeWo-RhoA-N19) or constitutively active RhoA (MeWo-RhoA-V14) were generated and subjected to UV radiation. A slight reduction in migration and invasion was observed in MeWo and MeWo-RhoA-V14 cells but not in MeWo-RhoA-N19 cells, which presented inefficient motility and invasiveness associated with stress fibers fragmentation. Proliferation and survival of RhoA-deficient cells were drastically reduced by UV compared to cells displaying normal or high RhoA activity, suggesting increased sensitivity to UV. Loss of RhoA activity also caused less efficient DNA repair, with elevated levels of DNA lesions such as strand breaks and cyclobutane pyrimidine dimers (CPDs). Thus, RhoA mediates genomic stability and represents a potential target for sensitizing metastatic tumors to genotoxic agents. PMID:26823948

  2. Cdc42p and Rho1p are sequentially activated and mechanistically linked to vacuole membrane fusion

    SciTech Connect

    Logan, Michael R.; Jones, Lynden; Eitzen, Gary

    2010-03-26

    Small monomeric GTPases act as molecular switches, regulating many biological functions via activation of membrane localized signaling cascades. Activation of their switch function is controlled by GTP binding and hydrolysis. Two Rho GTPases, Cdc42p and Rho1p, are localized to the yeast vacuole where they regulate membrane fusion. Here, we define a method to directly examine vacuole membrane Cdc42p and Rho1p activation based on their affinity to probes derived from effectors. Cdc42p and Rho1p showed unique temporal activation which aligned with distinct subreactions of in vitro vacuole fusion. Cdc42p was rapidly activated in an ATP-independent manner while Rho1p activation was kinetically slower and required ATP. Inhibitors that are known to block vacuole membrane fusion were examined for their effect on Cdc42p and Rho1p activation. Rdi1p, which inhibits the dissociation of GDP from Rho proteins, blocked both Cdc42p and Rho1p activation. Ligands of PI(4,5)P{sub 2} specifically inhibited Rho1p activation while pre-incubation with U73122, which targets Plc1p function, increased Rho1p activation. These results define unique activation mechanisms for Cdc42p and Rho1p, which may be linked to the vacuole membrane fusion mechanism.

  3. The Fer tyrosine kinase regulates interactions of Rho GDP-Dissociation Inhibitor α with the small GTPase Rac

    PubMed Central

    2010-01-01

    Background RhoGDI proteins are important regulators of the small GTPase Rac, because they shuttle Rac from the cytoplasm to membranes and also protect Rac from activation, deactivation and degradation. How the binding and release of Rac from RhoGDI is regulated is not precisely understood. Results We report that the non-receptor tyrosine kinase Fer is able to phosphorylate RhoGDIα and form a direct protein complex with it. This interaction is mediated by the C-terminal end of RhoGDIα. Activation of Fer by reactive oxygen species caused increased phosphorylation of RhoGDIα and pervanadate treatment further augmented this. Tyrosine phosphorylation of RhoGDIα by Fer prevented subsequent binding of Rac to RhoGDIα, but once a RhoGDIα-Rac complex was formed, the Fer kinase was not able to cause Rac release through tyrosine phosphorylation of preformed RhoGDIα-Rac complexes. Conclusions These results identify tyrosine phosphorylation of RhoGDIα by Fer as a mechanism to regulate binding of RhoGDIα to Rac. PMID:21122136

  4. RhoA-Mediated Functions in C3H10T1/2 Osteoprogenitors Are Substrate Topography Dependent.

    PubMed

    Ogino, Yoichiro; Liang, Ruiwei; Mendonça, Daniela B S; Mendonça, Gustavo; Nagasawa, Masako; Koyano, Kiyoshi; Cooper, Lyndon F

    2016-03-01

    Surface topography broadly influences cellular responses. Adherent cell activities are regulated, in part, by RhoA, a member of the Rho-family of GTPases. In this study, we evaluated the influence of surface topography on RhoA activity and associated cellular functions. The murine mesenchymal stem cell line C3H10T1/2 cells (osteoprogenitor cells) were cultured on titanium substrates with smooth topography (S), microtopography (M), and nanotopography (N) to evaluate the effect of surface topography on RhoA-mediated functions (cell spreading, adhesion, migration, and osteogenic differentiation). The influence of RhoA activity in the context of surface topography was also elucidated using RhoA pharmacologic inhibitor. Following adhesion, M and N adherent cells developed multiple projections, while S adherent cells had flattened and widespread morphology. RhoA inhibitor induced remarkable longer and thinner cytoplasmic projections on all surfaces. Cell adhesion and osteogenic differentiation was topography dependent with S < M and N surfaces. RhoA inhibition increased adhesion on S and M surfaces, but not N surfaces. Cell migration in a wound healing assay was greater on S versus M versus N surfaces and RhoA inhibitor increased S adherent cell migration, but not N adherent cell migration. RhoA inhibitor enhanced osteogenic differentiation in S adherent cells, but not M or N adherent cells. RhoA activity was surface topography roughness dependent (S < M, N). RhoA activity and -mediated functions are influenced by surface topography. Smooth surface adherent cells appear highly sensitive to RhoA function, while nano-scale topography adherent cell may utilize alternative cellular signaling pathway(s) to influence adherent cellular functions regardless of RhoA activity. PMID:26205718

  5. Determinants at the N- and C-termini of Gα12 required for activation of Rho-mediated signaling

    PubMed Central

    2013-01-01

    Background Heterotrimeric guanine nucleotide binding proteins of the G12/13 subfamily, which includes the α-subunits Gα12 and Gα13, stimulate the monomeric G protein RhoA through interaction with a distinct subset of Rho-specific guanine nucleotide exchange factors (RhoGEFs). The structural features that mediate interaction between Gα13 and RhoGEFs have been examined in crystallographic studies of the purified complex, whereas a Gα12:RhoGEF complex has not been reported. Several signaling responses and effector interactions appear unique to Gα12 or Gα13, despite their similarity in amino acid sequence. Methods To comprehensively examine Gα12 for regions involved in RhoGEF interaction, we screened a panel of Gα12 cassette substitution mutants for binding to leukemia-associated RhoGEF (LARG) and for activation of serum response element mediated transcription. Results We identified several cassette substitutions that disrupt Gα12 binding to LARG and the related p115RhoGEF. These Gα12 mutants also were impaired in activating serum response element mediated signaling, a Rho-dependent response. Most of these mutants matched corresponding regions of Gα13 reported to contact p115RhoGEF, but unexpectedly, several RhoGEF-uncoupling mutations were found within the N- and C-terminal regions of Gα12. Trypsin protection assays revealed several mutants in these regions as retaining conformational activation. In addition, charge substitutions near the Gα12 N-terminus selectively disrupted binding to LARG but not p115RhoGEF. Conclusions Several structural aspects of the Gα12:RhoGEF interface differ from the reported Gα13:RhoGEF complex, particularly determinants within the C-terminal α5 helix and structurally uncharacterized N-terminus of Gα12. Furthermore, key residues at the Gα12 N-terminus may confer selectivity for LARG as a downstream effector. PMID:23531275

  6. Lipid-induced Muscle Insulin Resistance Is Mediated by GGPPS via Modulation of the RhoA/Rho Kinase Signaling Pathway.

    PubMed

    Tao, Weiwei; Wu, Jing; Xie, Bing-Xian; Zhao, Yuan-Yuan; Shen, Ning; Jiang, Shan; Wang, Xiu-Xing; Xu, Na; Jiang, Chen; Chen, Shuai; Gao, Xiang; Xue, Bin; Li, Chao-Jun

    2015-08-14

    Elevated circulating free fatty acid levels are important contributors to insulin resistance in the muscle and liver, but the underlying mechanisms require further elucidation. Here, we show that geranylgeranyl diphosphate synthase 1 (GGPPS), which is a branch point enzyme in the mevalonic acid pathway, promotes lipid-induced muscle insulin resistance through activation of the RhoA/Rho kinase signaling pathway. We have found that metabolic perturbation would increase GGPPS expression in the skeletal muscles of db/db mice and high fat diet-fed mice. To address the metabolic effects of GGPPS activity in skeletal muscle, we generated mice with specific GGPPS deletions in their skeletal muscle tissue. Heterozygous knock-out of GGPPS in the skeletal muscle improved systemic insulin sensitivity and glucose homeostasis in mice fed both normal chow and high fat diets. These metabolic alterations were accompanied by activated PI3K/Akt signaling and enhanced glucose uptake in the skeletal muscle. Further investigation showed that the free fatty acid-stimulated GGPPS expression in the skeletal muscle was able to enhance the geranylgeranylation of RhoA, which further induced the inhibitory phosphorylation of IRS-1 (Ser-307) by increasing Rho kinase activity. These results implicate a crucial role of the GGPPS/RhoA/Rho kinase/IRS-1 pathway in skeletal muscle, in which it mediates lipid-induced systemic insulin resistance in obese mice. Therefore, skeletal muscle GGPPS may represent a potential pharmacological target for the prevention and treatment of obesity-related type 2 diabetes. PMID:26112408

  7. How we use WinRho in patients with idiopathic thrombocytopenic purpura.

    PubMed

    Stotler, Brie A; Schwartz, Joseph

    2015-11-01

    Primary immune thrombocytopenia (ITP) is an autoimmune disease that affects children and adults. WinRho SDF is a D immune globulin product that is Food and Drug Administration approved for the treatment of ITP in D+ pediatric and adult patients. WinRho is a plasma-derived biologic product dispensed from blood banks. Transfusion medicine physicians serve as a resource to health care providers regarding blood component and derivative usage and, as such, should be familiar with the use of WinRho for ITP, including the dosage, administration, and contraindications. This report details the transfusion medicine consultation practice and guidelines at a tertiary care academic medical center for the usage of WinRho SDF in patients with ITP. PMID:26094894

  8. Probing the {rho} spectral function in hot and dense nuclear matter by dileptons

    SciTech Connect

    Cassing, W.; Bratkovskaya, E.L.; Rapp, R.; Wambach, J.

    1998-02-01

    We present a dynamical study of e{sup +}e{sup {minus}} and {mu}{sup +}{mu}{sup {minus}} production in proton-nucleus and nucleus-nucleus collisions at CERN-SPS energies on the basis of the covariant transport approach HSD employing a momentum-dependent {rho}-meson spectral function that includes the pion modifications in the nuclear medium as well as the polarization of the {rho} meson due to resonant {rho}-N scattering. We find that the experimental data from the CERES and HELIOS-3 Collaborations can be described equally well as within the dropping {rho}-mass scenario. Whereas corresponding dilepton q{sub T} spectra are found to be very similar, the inclusive dilepton yield in the invariant mass range 0.85{le}M{le}1.0 GeV should allow us to disentangle the two scenarios experimentally. {copyright} {ital 1998} {ital The American Physical Society}

  9. Nu Rho Psi, The National Honor Society in Neuroscience: A decade of progress

    PubMed Central

    Hesp, Zoe C.; Cousens, Graham A.; Becker, Lora; Zee, Michele C.; Mickley, G. Andrew

    2016-01-01

    Nu Rho Psi, the National Honor Society in Neuroscience, celebrates its 10th anniversary by reflecting back upon a decade’s worth of growth, successes, and accomplishments of its membership. Fundamentally, Nu Rho Psi seeks to engage the nation’s best and brightest science students early in their educational pursuits and steer them towards future careers in neuroscience, thereby driving higher quality neuroscience education and research at all levels. This article details the history of Nu Rho Psi since its founding by the Faculty for Undergraduate Neuroscience (FUN) and reviews the current programs, benefits, and future initiatives of the Society. We make the case that Nu Rho Psi has enhanced the opportunities for undergraduate students of neuroscience and created a new culture among this vital cohort of budding scientists, reminiscent of the substantial network of faculty educators and departments of neuroscience established by FUN. PMID:27385933

  10. Nu Rho Psi, The National Honor Society in Neuroscience: A decade of progress.

    PubMed

    Hesp, Zoe C; Cousens, Graham A; Becker, Lora; Zee, Michele C; Mickley, G Andrew

    2016-01-01

    Nu Rho Psi, the National Honor Society in Neuroscience, celebrates its 10th anniversary by reflecting back upon a decade's worth of growth, successes, and accomplishments of its membership. Fundamentally, Nu Rho Psi seeks to engage the nation's best and brightest science students early in their educational pursuits and steer them towards future careers in neuroscience, thereby driving higher quality neuroscience education and research at all levels. This article details the history of Nu Rho Psi since its founding by the Faculty for Undergraduate Neuroscience (FUN) and reviews the current programs, benefits, and future initiatives of the Society. We make the case that Nu Rho Psi has enhanced the opportunities for undergraduate students of neuroscience and created a new culture among this vital cohort of budding scientists, reminiscent of the substantial network of faculty educators and departments of neuroscience established by FUN. PMID:27385933

  11. Further exploration of MRI techniques for liver T1rho quantification.

    PubMed

    Zhao, Feng; Yuan, Jing; Deng, Min; Lu, Pu-Xuan; Ahuja, Anil T; Wang, Yi-Xiang J

    2013-12-01

    With biliary duct ligation and CCl4 induced rat liver fibrosis models, recent studies showed that MR T1rho imaging is able to detect liver fibrosis, and the degree of fibrosis is correlated with the degree of elevation of the T1rho measurements, suggesting liver T1rho quantification may play an important role for liver fibrosis early detection and grading. It has also been reported it is feasible to obtain consistent liver T1rho measurement for human subjects at 3 Tesla (3 T), and preliminary clinical data suggest liver T1rho is increased in patients with cirrhosis. In these previous studies, T1rho imaging was used with the rotary-echo spin-lock pulse for T1rho preparation, and number of signal averaging (NSA) was 2. Due to the presence of inhomogeneous B0 field, artifacts may occur in the acquired T1rho-weighted images. The method described by Dixon et al. (Magn Reson Med 1996;36:90-4), which is a hard RF pulse with 135° flip angle and same RF phase as the spin-locking RF pulse is inserted right before and after the spin-locking RF pulse, has been proposed to reduce sensitivity to B0 field inhomogeneity in T1rho imaging. In this study, we compared the images scanned by rotary-echo spin-lock pulse method (sequence 1) and the pulse modified according to Dixon method (sequence 2). When the artifacts occurred in T1rho images, we repeated the same scan until satisfactory. We accepted images if artifact in liver was less than 10% of liver area by visual estimation. When NSA =2, the breath-holding duration for data acquisition of one slice scanning was 8 sec due to a delay time of 6,000 ms for magnetization restoration. If NSA =1, the duration was shortened to be 2 sec. In previous studies, manual region of interest (ROI) analysis of T1rho map was used. In this current study, histogram analysis was also applied to evaluate liver T1rho value on T1rho maps. MRI data acquisition was performed on a 3 T clinical scanner. There were 29 subjects with 61 examinations obtained

  12. Rho, nuclear actin, and actin-binding proteins in the regulation of transcription and gene expression

    PubMed Central

    Rajakylä, Eeva Kaisa; Vartiainen, Maria K

    2014-01-01

    Actin cytoskeleton is one of the main targets of Rho GTPases, which act as molecular switches on many signaling pathways. During the past decade, actin has emerged as an important regulator of gene expression. Nuclear actin plays a key role in transcription, chromatin remodeling, and pre-mRNA processing. In addition, the “status” of the actin cytoskeleton is used as a signaling intermediate by at least the MKL1-SRF and Hippo-pathways, which culminate in the transcriptional regulation of cytoskeletal and growth-promoting genes, respectively. Rho GTPases may therefore regulate gene expression by controlling either cytoplasmic or nuclear actin dynamics. Although the regulation of nuclear actin polymerization is still poorly understood, many actin-binding proteins, which are downstream effectors of Rho, are found in the nuclear compartment. In this review, we discuss the possible mechanisms and key proteins that may mediate the transcriptional regulation by Rho GTPases through actin. PMID:24603113

  13. Rho, nuclear actin, and actin-binding proteins in the regulation of transcription and gene expression.

    PubMed

    Rajakylä, Eeva Kaisa; Vartiainen, Maria K

    2014-01-01

    Actin cytoskeleton is one of the main targets of Rho GTPases, which act as molecular switches on many signaling pathways. During the past decade, actin has emerged as an important regulator of gene expression. Nuclear actin plays a key role in transcription, chromatin remodeling, and pre-mRNA processing. In addition, the "status" of the actin cytoskeleton is used as a signaling intermediate by at least the MKL1-SRF and Hippo-pathways, which culminate in the transcriptional regulation of cytoskeletal and growth-promoting genes, respectively. Rho GTPases may therefore regulate gene expression by controlling either cytoplasmic or nuclear actin dynamics. Although the regulation of nuclear actin polymerization is still poorly understood, many actin-binding proteins, which are downstream effectors of Rho, are found in the nuclear compartment. In this review, we discuss the possible mechanisms and key proteins that may mediate the transcriptional regulation by Rho GTPases through actin. PMID:24603113

  14. Measurement of the CP asymmetry and branching fraction of B0-->rho0K0.

    PubMed

    Aubert, B; Barate, R; Bona, M; Boutigny, D; Couderc, F; Karyotakis, Y; Lees, J P; Poireau, V; Tisserand, V; Zghiche, A; Grauges, E; Palano, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Battaglia, M; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Gill, M S; Groysman, Y; Jacobsen, R G; Kadyk, J A; Kerth, L T; Kolomensky, Yu G; Kukartsev, G; Lynch, G; Mir, L M; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; del Amo Sanchez, P; Barrett, M; Ford, K E; Harrison, T J; Hart, A J; Hawkes, C M; Morgan, S E; Watson, A T; Held, T; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schroeder, T; Steinke, M; Boyd, J T; Burke, J P; Cottingham, W N; Walker, D; Cuhadar-Donszelmann, T; Fulsom, B G; Hearty, C; Knecht, N S; Mattison, T S; McKenna, J A; Khan, A; Kyberd, P; Saleem, M; Sherwood, D J; Teodorescu, L; Blinov, V E; Bukin, A D; Druzhinin, V P; Golubev, V B; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Todyshev, K Yu; Best, D S; Bondioli, M; Bruinsma, M; Chao, M; Curry, S; Eschrich, I; Kirkby, D; Lankford, A J; Lund, P; Mandelkern, M; Mommsen, R K; Roethel, W; Stoker, D P; Abachi, S; Buchanan, C; Foulkes, S D; Gary, J W; Long, O; Shen, B C; Wang, K; Zhang, L; Hadavand, H K; Hill, E J; Paar, H P; Rahatlou, S; Sharma, V; Berryhill, J W; Campagnari, C; Cunha, A; Dahmes, B; Hong, T M; Kovalskyi, D; Richman, J D; Beck, T W; Eisner, A M; Flacco, C J; Heusch, C A; Kroseberg, J; Lockman, W S; Nesom, G; Schalk, T; Schumm, B A; Seiden, A; Spradlin, P; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dvoretskii, A; Fang, F; Hitlin, D G; Narsky, I; Piatenko, T; Porter, F C; Ryd, A; Samuel, A; Mancinelli, G; Meadows, B T; Mishra, K; Sokoloff, M D; Blanc, F; Bloom, P C; Chen, S; Ford, W T; Hirschauer, J F; Kreisel, A; Nagel, M; Nauenberg, U; Olivas, A; Ruddick, W O; Smith, J G; Ulmer, K A; Wagner, S R; Zhang, J; Chen, A; Eckhart, E A; Soffer, A; Toki, W H; Wilson, R J; Winklmeier, F; Zeng, Q; Altenburg, D D; Feltresi, E; Hauke, A; Jasper, H; Petzold, A; Spaan, B; Brandt, T; Klose, V; Lacker, H M; Mader, W F; Nogowski, R; Schubert, J; Schubert, K R; Schwierz, R; Sundermann, J E; Volk, A; Bernard, D; Bonneaud, G R; Grenier, P; Latour, E; Thiebaux, Ch; Verderi, M; Clark, P J; Gradl, W; Muheim, F; Playfer, S; Robertson, A I; Xie, Y; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Petrella, A; Piemontese, L; Prencipe, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Finocchiaro, G; Pacetti, S; Patteri, P; Peruzzi, I M; Piccolo, M; Rama, M; Zallo, A; Buzzo, A; Capra, R; Contri, R; Lo Vetere, M; Macri, M M; Monge, M R; Passaggio, S; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Brandenburg, G; Chaisanguanthum, K S; Morii, M; Wu, J; Dubitzky, R S; Marks, J; Schenk, S; Uwer, U; Bard, D J; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Flack, R L; Nash, J A; Nikolich, M B; Panduro Vazquez, W; Behera, P K; Chai, X; Charles, M J; Mallik, U; Meyer, N T; Ziegler, V; Cochran, J; Crawley, H B; Dong, L; Eyges, V; Meyer, W T; Prell, S; Rosenberg, E I; Rubin, A E; Gritsan, A V; Denig, A G; Fritsch, M; Schott, G; Arnaud, N; Davier, M; Grosdidier, G; Höcker, A; Le Diberder, F; Lepeltier, V; Lutz, A M; Oyanguren, A; Pruvot, S; Rodier, S; Roudeau, P; Schune, M H; Stocchi, A; Wang, W F; Wormser, G; Cheng, C H; Lange, D J; Wright, D M; Chavez, C A; Forster, I J; Fry, J R; Gabathuler, E; Gamet, R; George, K A; Hutchcroft, D E; Payne, D J; Schofield, K C; Touramanis, C; Bevan, A J; Di Lodovico, F; Menges, W; Sacco, R; Cowan, G; Flaecher, H U; Hopkins, D A; Jackson, P S; McMahon, T R; Ricciardi, S; Salvatore, F; Wren, A C; Brown, D N; Davis, C L; Allison, J; Barlow, N R; Barlow, R J; Chia, Y M; Edgar, C L; Lafferty, G D; Naisbit, M T; Williams, J C; Yi, J I; Chen, C; Hulsbergen, W D; Jawahery, A; Lae, C K; Roberts, D A; Simi, G; Blaylock, G; Dallapiccola, C; Hertzbach, S S; Li, X; Moore, T B; Saremi, S; Staengle, H; Cowan, R; Sciolla, G; Sekula, S J; Spitznagel, M; Taylor, F; Yamamoto, R K; Kim, H; McLachlin, S E; Patel, P M; Robertson, S H; Lazzaro, A; Lombardo, V; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Sanders, D A; Summers, D J; Zhao, H W; Brunet, S; Côté, D; Simard, M; Taras, P; Viaud, F B; Nicholson, H; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Monorchio, D; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M; Raven, G; Snoek, H L; Jessop, C P; Losecco, J M; Allmendinger, T; Benelli, G; Gan, K K; Honscheid, K; Hufnagel, D; Jackson, P D; Kagan, H; Kass, R; Rahimi, A M; Ter-Antonyan, R; Wong, Q K; Blount, N L; Brau, J; Frey, R; Igonkina, O; Lu, M; Rahmat, R; Sinev, N B; Strom, D; Strube, J; Torrence, E; Gaz, A; Margoni, M; Morandin, M; Pompili, A; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Voci, C; Benayoun, M; Chauveau, J; Briand, H; David, P; Del Buono, L; de la Vaissière, Ch; Hamon, O; Hartfiel, B L; John, M J J; Leruste, Ph; Malclès, J; Ocariz, J; Roos, L; Therin, G; Gladney, L; Panetta, J; Biasini, M; Covarelli, R; Angelini, C; Batignani, G; Bettarini, S; Bucci, F; Calderini, G; Carpinelli, M; Cenci, R; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Mazur, M A; Morganti, M; Neri, N; Paoloni, E; Rizzo, G; Walsh, J J; Haire, M; Judd, D; Wagoner, D E; Biesiada, J; Danielson, N; Elmer, P; Lau, Y P; Lu, C; Olsen, J; Smith, A J S; Telnov, A V; Bellini, F; Cavoto, G; D'Orazio, A; del Re, D; Di Marco, E; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Li Gioi, L; Mazzoni, M A; Morganti, S; Piredda, G; Polci, F; Safai Tehrani, F; Voena, C; Ebert, M; Schröder, H; Waldi, R; Adye, T; De Groot, N; Franek, B; Olaiya, E O; Wilson, F F; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Hamel de Monchenault, G; Kozanecki, W; Legendre, M; Vasseur, G; Yèche, Ch; Zito, M; Chen, X R; Liu, H; Park, W; Purohit, M V; Wilson, J R; Allen, M T; Aston, D; Bartoldus, R; Bechtle, P; Berger, N; Claus, R; Coleman, J P; Convery, M R; Cristinziani, M; Dingfelder, J C; Dorfan, J; Dubois-Felsmann, G P; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Graham, M T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Leith, D W G S; Li, S; Luitz, S; Luth, V; Lynch, H L; MacFarlane, D B; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Pulliam, T; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Stelzer, J; Su, D; Sullivan, M K; Suzuki, K; Swain, S K; Thompson, J M; Va'vra, J; van Bakel, N; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Yi, K; Young, C C; Burchat, P R; Edwards, A J; Majewski, S A; Petersen, B A; Roat, C; Wilden, L; Ahmed, S; Alam, M S; Bula, R; Ernst, J A; Jain, V; Pan, B; Saeed, M A; Wappler, F R; Zain, S B; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Ritchie, J L; Satpathy, A; Schilling, C J; Schwitters, R F; Izen, J M; Lou, X C; Ye, S; Bianchi, F; Gallo, F; Gamba, D; Bomben, M; Bosisio, L; Cartaro, C; Cossutti, F; Della Ricca, G; Dittongo, S; Lanceri, L; Vitale, L; Azzolini, V; Martinez-Vidal, F; Banerjee, Sw; Bhuyan, B; Brown, C M; Fortin, D; Hamano, K; Kowalewski, R; Nugent, I M; Roney, J M; Sobie, R J; Back, J J; Harrison, P F; Latham, T E; Mohanty, G B; Pappagallo, M; Band, H R; Chen, X; Cheng, B; Dasu, S; Datta, M; Flood, K T; Hollar, J J; Kutter, P E; Mellado, B; Mihalyi, A; Pan, Y; Pierini, M; Prepost, R; Wu, S L; Yu, Z; Neal, H

    2007-02-01

    We present a measurement of the branching fraction and time-dependent CP asymmetry of B(0)-->rho0K0. The results are obtained from a data sample of 227x10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at Stanford Linear Accelerator Center. From a time-dependent maximum likelihood fit yielding 111+/-19 signal events, we find B(B(0)-->rho0K0)=(4.9+/-0.8+/-0.9)x10(-6), where the first error is statistical and the second systematic. We report the measurement of the CP parameters S(rho)(0)K(0)S=0.20+/-0.52+/-0.24 and C(rho)(0)K(0)S=0.64+/-0.41+/-0.20. PMID:17358845

  15. Color transparency in hadronic attenuation of {rho}{sup 0} mesons

    SciTech Connect

    Gallmeister, K.; Kaskulov, M.; Mosel, U.

    2011-01-15

    Ongoing experiments at JLAB investigate the nuclear transparency in exclusive {rho}{sup 0}(770) electroproduction off nuclei. In this work we present transport model predictions for the attenuation of {rho}{sup 0}s in nuclei and for color transparency (CT) effects as observable at CLAS with a 5 GeV electron beam energy. A full event simulation developed here permits to study the impact of actual experimental acceptance conditions and kinematical cuts. The exclusive (e,e{sup '{rho}0}) cross section off nucleons is described by diffractive and color string breaking mechanisms extended toward the onset of the deep inelastic regime. Different hadronization and CT scenarios are compared. We show that a detailed analysis of the elementary cross section, nuclear effects, and experimental cuts is needed to reveal the early onset of {rho}-CT at present JLAB energies.

  16. Lovastatin-induced RhoA modulation and its effect on senescence in prostate cancer cells

    SciTech Connect

    Lee, Jeeyun; Lee, Inkyoung; Park, Chaehwa; Kang, Won Ki . E-mail: wkkang@smc.samsung.co.kr

    2006-01-20

    Lovastatin inhibits a 3-hydroxy 3-methylglutaryl coenzyme A reductase and prevents the synthesis of cholesterol precursors, such as farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP), responsible for important cell signaling in cell proliferation and migration. Recently, the anti-cancer effect of lovastatin has been suggested in various tumor types. In this study, we showed that a low dose lovastatin induced senescence and G1 cell cycle arrest in human prostate cancer cells. Addition of GGPP or mevalonate, but not FPP, prevented the lovastatin-induced G1 phase cell cycle arrest and cell senescence. We found that constitutively active RhoA (caRhoA) reversed lovastatin-induced senescence in caRhoA-transfected PC-3 cells. Thus, we postulate that modulation of RhoA may be critical in lovastatin-induced senescence in PC-3 cells.

  17. Role of Rho kinase isoforms in murine allergic airway responses.

    PubMed

    Zhu, M; Liu, P-Y; Kasahara, D I; Williams, A S; Verbout, N G; Halayko, A J; Fedulov, A; Shoji, T; Williams, E S; Noma, K; Shore, S A; Liao, J K

    2011-10-01

    Inhibition of Rho-associated coiled-coil forming kinases (ROCKs) reduces allergic airway responses in mice. The purpose of this study was to determine the roles of the two ROCK isoforms, ROCK1 and ROCK2, in these responses. Wildtype (WT) mice and heterozygous ROCK1 and ROCK2 knockout mice (ROCK1(+/-) and ROCK2(+/-), respectively) were sensitised and challenged with ovalbumin. ROCK expression and activation were assessed by western blotting. Airway responsiveness was measured by forced oscillation. Bronchoalveolar lavage was performed and the lungs were fixed for histological assessment. Compared with WT mice, ROCK1 and ROCK2 expression were 50% lower in lungs of ROCK1(+/-) and ROCK2(+/-) mice, respectively, without changes in the other isoform. In WT lungs, ROCK activation increased after ovalbumin challenge and was sustained for several hours. This activation was reduced in ROCK1(+/-) and ROCK2(+/-) lungs. Airway responsiveness was comparable in WT, ROCK1(+/-), and ROCK2(+/-) mice challenged with PBS. Ovalbumin challenge caused airway hyperresponsiveness in WT, but not ROCK1(+/-) or ROCK2(+/-) mice. Lavage eosinophils and goblet cell hyperplasia were significantly reduced in ovalbumin-challenged ROCK1(+/-) and ROCK2(+/-) versus WT mice. Ovalbumin-induced changes in lavage interleukin-13, interleukin-5 and lymphocytes were also reduced in ROCK1(+/-) mice. In conclusion, both ROCK1 and ROCK2 are important in regulating allergic airway responses. PMID:21565918

  18. Exclusive rho^0 electroproduction on the proton at CLAS

    SciTech Connect

    Morrow, Steven; Guidal, Michel; Garcon, Michel; Laget, Jean; Smith, Elton; Adams, Gary; Adhikari, Krishna; Aghasyan, Mher; Amaryan, Moscov; Amaryan, Moskov; Anghinolfi, Marco; Asryan, G.; Audit, Gerard; Avagyan, Harutyun; Bagdasaryan, H.; Baillie, Nathan; Ball, J.P.; Ball, Jacques; Baltzell, Nathan; Barrow, Steve; Battaglieri, Marco; Bedlinskiy, Ivan; Bektasoglu, Mehmet; Bellis, Matthew; Benmouna, Nawal; Berman, Barry; Biselli, Angela; Blaszczyk, Lukasz; Bonner, Billy; Bookwalter, Craig; Bouchigny, Sylvain; Boyarinov, Sergey; Bradford, Robert; Branford, Derek; Briscoe, William; Brooks, William; Bultmann, S.; Bueltmann, Stephen; Burkert, Volker; Butuceanu, Cornel; Calarco, John; Careccia, Sharon; Carman, Daniel; Carnahan, Bryan; Casey, Liam; Cazes, Antoine; Chen, Shifeng; Cheng, Lu; Cole, Philip; Collins, Patrick; Coltharp, Philip; Cords, Dieter; Corvisiero, Pietro; Crabb, Donald; Crannell, Hall; Crede, Volker; Cummings, John; Dale, Daniel; Dashyan, Natalya; De Masi, Rita; De Vita, Raffaella; De Sanctis, Enzo; Degtiarenko, Pavel; Denizli, Haluk; Dennis, Lawrence; Deur, Alexandre; Dhamija, Seema; Dharmawardane, Kahanawita; Dhuga, Kalvir; Dickson, Richard; Didelez, Jean-Pierre; Djalali, Chaden; Dodge, Gail; Doughty, David; Dugger, Michael; Dytman, Steven; Dzyubak, Oleksandr; Egiyan, Hovanes; Egiyan, Kim; Elfassi, Lamiaa; Elouadrhiri, Latifa; Eugenio, Paul; Fatemi, Renee; Fedotov, Gleb; Fersch, Robert; Feuerbach, Robert; Forest, Tony; Fradi, Ahmed; Gavalian, Gagik; Gevorgyan, Nerses; Gilfoyle, Gerard; Giovanetti, Kevin; Girod, Francois-Xavier; Goetz, John; Gohn, Wesley; Gordon, Christopher; Gothe, Ralf; Graham, Lewis; Griffioen, Keith; Guillo, Matthieu; Guler, Nevzat; Guo, Lei; Gyurjyan, Vardan; Hadjidakis, Cynthia; Hafidi, Kawtar; Hakobyan, Hayk; Hanretty, Charles; Hardie, John; Hassall, Neil; Heddle, David; Hersman, F.; Hicks, Kenneth; Hleiqawi, Ishaq; Holtrop, Maurik; Hourany, E.; Hyde, Charles; Ilieva, Yordanka; Ireland, David; Ishkhanov, Boris; Isupov, Evgeny; Ito, Mark; Jenkins, David; Jo, Hyon-Suk; Johnstone, John; Joo, Kyungseon; Juengst, Henry; Kalantarians, Narbe; Keller, Dustin; Kellie, James; Khandaker, Mahbubul; Khetarpal, Puneet; Kim, Wooyoung; Klein, Andreas; Klein, Franz; Klimenko, Alexei; Kossov, Mikhail; Kramer, Laird; Kubarovsky, Valery; Kuhn, Joachim; Kuhn, Sebastian; Kuleshov, Sergey; Kuznetsov, Viacheslav; Lachniet, Jeff; Langheinrich, Jorn; Lawrence, Dave; Li, Ji; Livingston, Kenneth; Lu, Haiyun; MacCormick, Marion; Marchand, Claude; Markov, Nikolai; Mattione, Paul; McAleer, Simeon; McCracken, Michael; McKinnon, Bryan; McNabb, John; Mecking, Bernhard; Mehrabyan, Surik; Melone, Joseph; Mestayer, Mac; Meyer, Curtis; Mibe, Tsutomu; Mikhaylov, Konstantin; Minehart, Ralph; Mirazita, Marco; Miskimen, Rory; Mokeev, Viktor; Morand, Ludyvine; Moreno, Brahim; Moriya, Kei; Moteabbed, Maryam; Mueller, James; Munevar Espitia, Edwin; Mutchler, Gordon; Nadel-Turonski, Pawel; Nasseripour, Rakhsha; Niccolai, Silvia; Niculescu, Gabriel; Niculescu, Maria-Ioana; Niczyporuk, Bogdan; Niroula, Megh; Niyazov, Rustam; Nozar, Mina; O'Rielly, Grant; Osipenko, Mikhail; Ostrovidov, Alexander; Park, Kijun; Park, Sungkyun; Pasyuk, Evgueni; Paterson, Craig; Pereira, S.Anefalos; Philips, Sasha; Pierce, Joshua; Pivnyuk, Nikolay; Pocanic, Dinko; Pogorelko, Oleg; Polli, Ermanno; Popa, Iulian; Pozdnyakov, Sergey; Preedom, Barry; Price, John; Procureur, Sebastien; Prok, Yelena; Protopopescu, Dan; Qin, Liming; Raue, Brian; Riccardi, Gregory; Ricco, Giovanni; Ripani, Marco; Ritchie, Barry; Rosner, Guenther; Rossi, Patrizia; Rubin, Philip; Sabatie, Franck; Saini, Mukesh; Salamanca, Julian; Salgado, Carlos; Santoro, Joseph; Sapunenko, Vladimir; Schott, Diane; Schumacher, Reinhard; Serov, Vladimir; Sharabian, Youri; Sharov, Dmitri; Shvedunov, Nikolay; Skabelin, Alexander; Smith, Lee; Sober, Daniel; Sokhan, Daria; Stavinskiy, Aleksey; Stepanyan, Samuel; Stepanyan, Stepan; Stokes, Burnham; Stoler, Paul; Strakovski, Igor; Strauch, Steffen; Taiuti, Mauro

    2009-01-01

    The $e p\\to e^\\prime p \\rho^0$ reaction has been measured, using the 5.754 GeV electron beam of Jefferson Lab and the CLAS detector. This represents the largest ever set of data for this reaction in the valence region. Integrated and differential cross sections are presented. The $W$, $Q^2$ and $t$ dependences of the cross section are compared to theoretical calculations based on $t$-channel meson-exchange Regge theory on the one hand and on quark handbag diagrams related to Generalized Parton Distributions (GPDs) on the other hand. The Regge approach can describe at the $\\approx$ 30% level most of the features of the present data while the two GPD calculations that are presented in this article which succesfully reproduce the high energy data strongly underestimate the present data. The question is then raised whether this discrepancy originates from an incomplete or inexact way of modelling the GPDs or the associated hard scattering amplitude or whether the GPD formalism is simply in

  19. The Yersinia pseudotuberculosis cytotoxic necrotizing factor (CNFY) selectively activates RhoA.

    PubMed

    Hoffmann, Claudia; Pop, Marius; Leemhuis, Jost; Schirmer, Jörg; Aktories, Klaus; Schmidt, Gudula

    2004-04-16

    The cytotoxic necrotizing factors (CNF)1 and CNF2 from pathogenic Escherichia coli strains activate RhoA, Rac1, and Cdc42 by deamidation of Gln63 (RhoA) or Gln61 (Rac and Cdc42). Recently, a novel cytotoxic necrotizing factor termed CNFY was identified in Yersinia pseudotuberculosis strains (Lockman, H. A., Gillespie, R. A., Baker, B. D., and Shakhnovich, E. (2002) Infect. Immun. 70, 2708-2714). We amplified the cnfy gene from genomic DNA of Y. pseudotuberculosis, cloned and expressed the recombinant protein, and studied its activity. Recombinant GST-CNFY induced morphological changes in HeLa cells and caused an upward shift of RhoA in SDS-PAGE, as is known for GST-CNF1 and GST-CNF2. Mass spectrometric analysis of GST-CNFY-treated RhoA confirmed deamidation at Glu63. Treatment of RhoA, Rac1, and Cdc42 with GST-CNFY decreased their GTPase activities, indicating that all of these Rho proteins could serve as substrates for GST-CNFY in vitro. In contrast, RhoA, but not Rac or Cdc42, was the substrate of GST-CNFY in culture cells. GST-CNFY caused marked stress fiber formation in HeLa cells after 2 h. In contrast to GST-CNF1, formation of filopodia or lamellipodia was not induced with GST-CNFY. Accordingly, effector pull-down experiments with lysates of toxin-treated cells revealed strong activation of RhoA but no activation of Rac1 or Cdc42 after 6 h of GST-CNFY-treatment. Moreover, in rat hippocampal neurons, GST-CNFY results in the retraction of neurites, indicating RhoA activation. In contrast, no activation of Rac or Cdc42 was found. Altogether, our data suggest that CNFY from Y. pseudotuberculosis is a strong, selective activator of RhoA, which can be used as a powerful tool for constitutive RhoA activation without concomitant activation of Rac1 or Cdc42. PMID:14761941

  20. Analysis of a minimal Rho-GTPase circuit regulating cell shape

    NASA Astrophysics Data System (ADS)

    Holmes, William R.; Edelstein-Keshet, Leah

    2016-08-01

    Networks of Rho-family GTPases regulate eukaryotic cell polarization and motility by controlling assembly and contraction of the cytoskeleton. The mutually inhibitory Rac–Rho circuit is emerging as a central, regulatory hub that can affect the shape and motility phenotype of eukaryotic cells. Recent experimental manipulation of the amounts of Rac and Rho or their regulators (guanine nucleotide-exchange factors, GTPase-activating proteins, guanine nucleotide dissociation inhibitors) have been shown to bias the prevalence of these different states and promote transitions between them. Here we show that part of this data can be understood in terms of inherent Rac–Rho mutually inhibitory dynamics. We analyze a spatio-temporal mathematical model of Rac–Rho dynamics to produce a detailed set of predictions of how parameters such as GTPase rates of activation and total amounts affect cell decisions (such as Rho-dominated contraction, Rac-dominated spreading, and spatially segregated Rac–Rho polarization). We find that in some parameter regimes, a cell can take on any of these three fates depending on its environment or stimuli. We also predict how experimental manipulations (corresponding to parameter variations) can affect cell shapes observed. Our methods are based on local perturbation analysis (a kind of nonlinear stability analysis), and an approximation of nonlinear feedback by sharp switches. We compare the Rac–Rho model to an even simpler single-GTPase (‘wave-pinning’) model and demonstrate that the overall behavior is inherent to GTPase properties, rather than stemming solely from network topology.

  1. Errors in quantitative T1rho imaging and the correction methods.

    PubMed

    Chen, Weitian

    2015-08-01

    The spin-lattice relaxation time constant in rotating frame (T1rho) is useful for assessment of the properties of macromolecular environment inside tissue. Quantification of T1rho is found promising in various clinical applications. However, T1rho imaging is prone to image artifacts and quantification errors, which remains one of the greatest challenges to adopt this technique in routine clinical practice. The conventional continuous wave spin-lock is susceptible to B1 radiofrequency (RF) and B0 field inhomogeneity, which appears as banding artifacts in acquired images. A number of methods have been reported to modify T1rho prep RF pulse cluster to mitigate this effect. Adiabatic RF pulse can also be used for spin-lock with insensitivity to both B1 RF and B0 field inhomogeneity. Another source of quantification error in T1rho imaging is signal evolution during imaging data acquisition. Care is needed to affirm such error does not take place when specific pulse sequence is used for imaging data acquisition. Another source of T1rho quantification error is insufficient signal-to-noise ratio (SNR), which is common among various quantitative imaging approaches. Measurement of T1rho within an ROI can mitigate this issue, but at the cost of reduced resolution. Noise-corrected methods are reported to address this issue in pixel-wise quantification. For certain tissue type, T1rho quantification can be confounded by magic angle effect and the presence of multiple tissue components. Review of these confounding factors from inherent tissue properties is not included in this article. PMID:26435922

  2. Leptin augments coronary vasoconstriction and smooth muscle proliferation via a Rho-kinase-dependent pathway.

    PubMed

    Noblet, Jillian N; Goodwill, Adam G; Sassoon, Daniel J; Kiel, Alexander M; Tune, Johnathan D

    2016-05-01

    Leptin has been implicated as a key upstream mediator of pathways associated with coronary vascular dysfunction and disease. The purpose of this investigation was to test the hypothesis that leptin modifies the coronary artery proteome and promotes increases in coronary smooth muscle contraction and proliferation via influences on Rho kinase signaling. Global proteomic assessment of coronary arteries from lean swine cultured with obese concentrations of leptin (30 ng/mL) for 3 days revealed significant alterations in the coronary artery proteome (68 proteins) and identified an association between leptin treatment and calcium signaling/contraction (four proteins) and cellular growth and proliferation (35 proteins). Isometric tension studies demonstrated that both acute (30 min) and chronic (3 days, serum-free media) exposure to obese concentrations of leptin potentiated depolarization-induced contraction of coronary arteries. Inhibition of Rho kinase significantly reduced leptin-mediated increases in coronary artery contractions. The effects of leptin on the functional expression of Rho kinase were time-dependent, as acute treatment increased Rho kinase activity while chronic (3 day) exposure was associated with increases in Rho kinase protein abundance. Proliferation assays following chronic leptin administration (8 day, serum-containing media) demonstrated that leptin augmented coronary vascular smooth muscle proliferation and increased Rho kinase activity. Inhibition of Rho kinase significantly reduced these effects of leptin. Taken together, these findings demonstrate that leptin promotes increases in coronary vasoconstriction and smooth muscle proliferation and indicate that these phenotypic effects are associated with alterations in the coronary artery proteome and dynamic effects on the Rho kinase pathway. PMID:26975316

  3. Soft X-ray observation of the Rho Ophiuchus dark cloud region

    NASA Technical Reports Server (NTRS)

    Apparao, K. M. V.; Hayakawa, S.; Hearn, D. R.

    1979-01-01

    Soft X-rays (0.1-0.8 keV) from the region including the Rho Oph dark cloud were observed with the SAS-3 low-energy X-ray telescope. No X-ray absorption by the cloud was observed. This indicates that the diffuse component of soft X-rays in this region is mostly from the foreground of the Rho Oph cloud which is located at a distance of 160-200 pc.

  4. Substrate rigidity regulates Ca2+ oscillation via RhoA pathway in stem cells

    PubMed Central

    Kim, Tae-Jin; Seong, Jihye; Ouyang, Mingxing; Sun, Jie; Lu, Shaoying; Hong, Jun Pyu; Wang, Ning; Wang, Yingxiao

    2008-01-01

    Substrate rigidity plays crucial roles in regulating cellular functions, such as cell spreading, traction forces, and stem cell differentiation. However, it is not clear how substrate rigidity influences early cell signaling events such as calcium in living cells. Using highly-sensitive Ca2+ biosensors based on fluorescence resonance energy transfer (FRET), we investigated the molecular mechanism by which substrate rigidity affects calcium signaling in human mesenchymal stem cells (HMSCs). Spontaneous Ca2+ oscillations were observed inside the cytoplasm and the endoplasmic reticulum (ER) using the FRET biosensors targeted at subcellular locations in cells plated on rigid dishes. Lowering the substrate stiffness to 1 kPa significantly inhibited both the magnitudes and frequencies of the cytoplasmic Ca2+ oscillation in comparison to stiffer or rigid substrate. This Ca2+ oscillation was shown to be dependent on ROCK, a downstream effector molecule of RhoA, but independent of actin filaments, microtubules, myosin light chain kinase, or myosin activity. Lysophosphatidic acid, which activates RhoA, also inhibited the frequency of the Ca2+ oscillation. Consistently, either a constitutive active mutant of RhoA (RhoA-V14) or a dominant negative mutant of RhoA (RhoA-N19) inhibited the Ca2+ oscillation. Further experiments revealed that HMSCs cultured on gels with low elastic moduli displayed low RhoA activities. Therefore, our results demonstrate that RhoA and its downstream molecule ROCK may mediate the substrate rigidity-regulated Ca2+ oscillation, which determines the physiological functions of HMSCs. PMID:18844232

  5. The natural degeneration course in the T1rho values of normal knee cartilage.

    PubMed

    Goto, Hajimu; Iwama, Yuki; Fujii, Masahiko; Aoyama, Nobukazu; Kubo, Seiji; Kuroda, Ryosuke; Ohno, Yoshiharu; Sugimura, Kazuro

    2011-01-01

    The purpose of our study is to investigate whether there is an age-related change in T1 rho values and to evaluate the effects of weight bearing on age-related increase in T1 rho values of normal cartilage. Thirty-two asymptomatic patients were examined using a 3.0T MRI to determine knee cartilage T1 rho values. Femorotibial and patella cartilage was defined as weight-bearing cartilage (WB-C) and non-weight-bearing cartilage (NWB-C), respectively. The femoral cartilage was divided into weight-bearing (WB-P) and less-weight-bearing (LWB-P) portions. Pearson's correlation coefficient and single regression analysis were used to assess the relationship between cartilage T1 rho values and age. The slopes of the regression lines of cartilage T1 rho values and age were compared between WB-C and NWB-C and between WB-P and LWB-P. Cartilage T1 rho values correlated positively with aging for all cartilage regions and all age groups (p<0.001). In the medial femoral cartilage, the age-related increase in T1 rho values was significantly greater for WB-P than for NWB-P (p<0.05). For several cartilage regions, this increase was greater for WB-C than for LWB-C (p<0.05). The T1 rho value is very sensitive to age-related cartilage degeneration and weight bearing-related degeneration, and hence may be a very sensitive and useful measure for the early diagnosis of osteoarthritis. PMID:22971986

  6. Effects of phased joint intervention on Rho/ROCK expression levels in patients with portal hypertension

    PubMed Central

    Shi, Min; Wei, Jue; Meng, Wen-Ying; Wang, Na; Wang, Ting; Wang, Yu-Gang

    2016-01-01

    The current study investigated the effects of phased joint intervention on clinical efficacy and Rho/Rho-associated coil protein kinase (ROCK) expression in patients with portal hypertension complicated by esophageal variceal bleeding (EVB) and hypersplenism. Patients with portal hypertension (n=53) caused by liver cirrhosis complicated by EVB and hypersplenism treated with phased joint intervention were assessed, and portal hemodynamics, blood, liver function, complications, and rebleeding incidence were analyzed. Reverse transcription-quantitative polymerase chain reaction was used to measure Rho, ROCK1 and ROCK2 mRNA expression levels in peripheral blood mononuclear cells prior to and following phased joint intervention, and western blotting was employed to determine the protein expression levels of Rho, ROCK1, ROCK2, phosphorylated (p) myosin phosphatase target subunit 1 (MYPT1) and total-MYPT1. All patients underwent an emergency assessment of hemostasis with a 100% success rate. Varicose veins were alleviated, and portal hemodynamics and liver function improved following intervention. Furthermore, preoperative and postoperative expression levels of Rho, ROCK1 and ROCK2 mRNA were higher compared with the control group. Notably, the mRNA expression levels of Rho, ROCK1 and ROCK2 in the postoperative group were significantly lower when compared with the preoperative group. Protein expression levels of Rho, ROCK1, ROCK2 and pMYPT1 in the postoperative group were lower, as compared with the preoperative group. Concentration levels of transforming growth factor-β1, connective tissue growth factor and platelet-derived growth factor in peripheral blood were significantly reduced following phased joint intervention. Therefore, the present findings demonstrated that phased joint intervention is able to effectively treat EVB and hypersplenism, and improve liver function. The efficacy of phased joint intervention may be associated with its role in the regulation of the

  7. Errors in quantitative T1rho imaging and the correction methods

    PubMed Central

    2015-01-01

    The spin-lattice relaxation time constant in rotating frame (T1rho) is useful for assessment of the properties of macromolecular environment inside tissue. Quantification of T1rho is found promising in various clinical applications. However, T1rho imaging is prone to image artifacts and quantification errors, which remains one of the greatest challenges to adopt this technique in routine clinical practice. The conventional continuous wave spin-lock is susceptible to B1 radiofrequency (RF) and B0 field inhomogeneity, which appears as banding artifacts in acquired images. A number of methods have been reported to modify T1rho prep RF pulse cluster to mitigate this effect. Adiabatic RF pulse can also be used for spin-lock with insensitivity to both B1 RF and B0 field inhomogeneity. Another source of quantification error in T1rho imaging is signal evolution during imaging data acquisition. Care is needed to affirm such error does not take place when specific pulse sequence is used for imaging data acquisition. Another source of T1rho quantification error is insufficient signal-to-noise ratio (SNR), which is common among various quantitative imaging approaches. Measurement of T1rho within an ROI can mitigate this issue, but at the cost of reduced resolution. Noise-corrected methods are reported to address this issue in pixel-wise quantification. For certain tissue type, T1rho quantification can be confounded by magic angle effect and the presence of multiple tissue components. Review of these confounding factors from inherent tissue properties is not included in this article. PMID:26435922

  8. Analysis of a minimal Rho-GTPase circuit regulating cell shape.

    PubMed

    Holmes, William R; Edelstein-Keshet, Leah

    2016-01-01

    Networks of Rho-family GTPases regulate eukaryotic cell polarization and motility by controlling assembly and contraction of the cytoskeleton. The mutually inhibitory Rac-Rho circuit is emerging as a central, regulatory hub that can affect the shape and motility phenotype of eukaryotic cells. Recent experimental manipulation of the amounts of Rac and Rho or their regulators (guanine nucleotide-exchange factors, GTPase-activating proteins, guanine nucleotide dissociation inhibitors) have been shown to bias the prevalence of these different states and promote transitions between them. Here we show that part of this data can be understood in terms of inherent Rac-Rho mutually inhibitory dynamics. We analyze a spatio-temporal mathematical model of Rac-Rho dynamics to produce a detailed set of predictions of how parameters such as GTPase rates of activation and total amounts affect cell decisions (such as Rho-dominated contraction, Rac-dominated spreading, and spatially segregated Rac-Rho polarization). We find that in some parameter regimes, a cell can take on any of these three fates depending on its environment or stimuli. We also predict how experimental manipulations (corresponding to parameter variations) can affect cell shapes observed. Our methods are based on local perturbation analysis (a kind of nonlinear stability analysis), and an approximation of nonlinear feedback by sharp switches. We compare the Rac-Rho model to an even simpler single-GTPase ('wave-pinning') model and demonstrate that the overall behavior is inherent to GTPase properties, rather than stemming solely from network topology. PMID:27434017

  9. Structural and functional regulation of tight junctions by RhoA and Rac1 small GTPases.

    PubMed

    Jou, T S; Schneeberger, E E; Nelson, W J

    1998-07-13

    Tight junctions (TJ) govern ion and solute diffusion through the paracellular space (gate function), and restrict mixing of membrane proteins and lipids between membrane domains (fence function) of polarized epithelial cells. We examined roles of the RhoA and Rac1 GTPases in regulating TJ structure and function in MDCK cells using the tetracycline repressible transactivator to regulate RhoAV14, RhoAN19, Rac1V12, and Rac1N17 expression. Both constitutively active and dominant negative RhoA or Rac1 perturbed TJ gate function (transepithelial electrical resistance, tracer diffusion) in a dose-dependent and reversible manner. Freeze-fracture EM and immunofluoresence microscopy revealed abnormal TJ strand morphology and protein (occludin, ZO-1) localization in RhoAV14 and Rac1V12 cells. However, TJ strand morphology and protein localization appeared normal in RhoAN19 and Rac1N17 cells. All mutant GTPases disrupted the fence function of the TJ (interdomain diffusion of a fluorescent lipid), but targeting and organization of a membrane protein in the apical membrane were unaffected. Expression levels and protein complexes of occludin and ZO-1 appeared normal in all mutant cells, although ZO-1 was more readily solubilized from RhoAV14-expressing cells with Triton X-100. These results show that RhoA and Rac1 regulate gate and fence functions of the TJ, and play a role in the spatial organization of TJ proteins at the apex of the lateral membrane. PMID:9660866

  10. RhoA GTPase Switch Controls Cx43-Hemichannel Activity through the Contractile System

    PubMed Central

    Hertens, Fréderic; Parys, Jan B.; Leybaert, Luc; Vereecke, Johan; Himpens, Bernard; Bultynck, Geert

    2012-01-01

    ATP-dependent paracrine signaling, mediated via the release of ATP through plasma membrane-embedded hemichannels of the connexin family, coordinates a synchronized response between neighboring cells. Connexin 43 (Cx43) hemichannels that are present in the plasma membrane need to be tightly regulated to ensure cell viability. In monolayers of bovine corneal endothelial cells (BCEC),Cx43-mediated ATP release is strongly inhibited when the cells are treated with inflammatory mediators, in particular thrombin and histamine. In this study we investigated the involvement of RhoA activation in the inhibition of hemichannel-mediated ATP release in BCEC. We found that RhoA activation occurs rapidly and transiently upon thrombin treatment of BCEC. The RhoA activity correlated with the onset of actomyosin contractility that is involved in the inhibition of Cx43 hemichannels. RhoA activation and inhibition of Cx43-hemichannel activity were both prevented by pre-treatment of the cells with C3-toxin as well as knock down of RhoA by siRNA. These findings provide evidence that RhoA activation is a key player in thrombin-induced inhibition of Cx43-hemichannel activity. This study demonstrates that RhoA GTPase activity is involved in the acute inhibition of ATP-dependent paracrine signaling, mediated by Cx43 hemichannels, in response to the inflammatory mediator thrombin. Therefore, RhoA appears to be an important molecular switch that controls Cx43 hemichannel openings and hemichannel-mediated ATP-dependent paracrine intercellular communication under (patho)physiological conditions of stress. PMID:22860057

  11. Analysis of pulmonary vasodilator responses to the Rho-kinase inhibitor fasudil in the anesthetized rat.

    PubMed

    Badejo, Adeleke M; Dhaliwal, Jasdeep S; Casey, David B; Gallen, Thomas B; Greco, Anthony J; Kadowitz, Philip J

    2008-11-01

    The small GTP-binding protein Rho and its downstream effector, Rho-kinase, are important regulators of vasoconstrictor tone. Rho-kinase is upregulated in experimental models of pulmonary hypertension, and Rho-kinase inhibitors decrease pulmonary arterial pressure in rodents with monocrotaline and chronic hypoxia-induced pulmonary hypertension. However, less is known about responses to fasudil when pulmonary vascular resistance is elevated on an acute basis by vasoconstrictor agents and ventilatory hypoxia. In the present study, intravenous injections of fasudil reversed pulmonary hypertensive responses to intravenous infusion of the thromboxane receptor agonist, U-46619 and ventilation with a 10% O(2) gas mixture and inhibited pulmonary vasoconstrictor responses to intravenous injections of angiotensin II, BAY K 8644, and U-46619 without prior exposure to agonists, which can upregulate Rho-kinase activity. The calcium channel blocker isradipine and fasudil had similar effects and in small doses had additive effects in blunting vasoconstrictor responses, suggesting parallel and series mechanisms in the lung. When pulmonary vascular resistance was increased with U-46619, fasudil produced similar decreases in pulmonary and systemic arterial pressure, whereas isradipine produced greater decreases in systemic arterial pressure. The hypoxic pressor response was enhanced by 5-10 mg/kg iv nitro-L-arginine methyl ester (L-NAME), and fasudil or isradipine reversed the pulmonary hypertensive response to hypoxia in control and in L-NAME-treated animals, suggesting that the response is mediated by Rho-kinase and L-type Ca(2+) channels. These results suggest that Rho-kinase is constitutively active in regulating baseline tone and vasoconstrictor responses in the lung under physiological conditions and that Rho-kinase inhibition attenuates pulmonary vasoconstrictor responses to agents that act by different mechanisms without prior exposure to the agonist. PMID:18689606

  12. Calibration issues in delta alpha /alpha .

    NASA Astrophysics Data System (ADS)

    Molaro, Paolo; Centurión, Miriam; Levshakov, Sergei

    Laser Comb Wavelength calibration shows that the ThAr one is locally unreliable with possible deviations of up to 100 {m s}-1 within one order range, while delivering an overall 1 {m s}-1 accuracy (Wilken et al 2009). Such deviation corresponds to delta alpha /alpha ≈ 7* 10-6 for a Fe II-Mg II pair. Comparison of line shifts among the 5 Fe II lines, with almost identical sensitivity to fine structure constant changes, offers a clean way to directly test the presence of possible local wavelength calibration errors of whatever origin. We analyzed 5 absorption systems, with zabs ranging from 1.15 to 2.19 towards 3 bright QSOs. The results show that while some lines are aligned within 20 {m s}-1, others reveal large deviations reaching 200 {m s}-1 or higher and corresponding to a delta alpha /alpha > 10-5 level. The origin of these deviations is not clearly identified but could be related to the adaptation of wavelength calibration to CCD manufacturing irregularities. These results suggest that to draw conclusions from delta alpha /alpha analysis based on one or only few lines must be done with extreme care.

  13. Rho/MRTF-A-Induced Integrin Expression Regulates Angiogenesis in Differentiated Multipotent Mesenchymal Stem Cells

    PubMed Central

    Zhang, Rui; Wang, Nan; Zhang, Man; Zhang, Li-Nan; Guo, Zhi-Xia; Luo, Xue-Gang; Zhou, Hao; He, Hong-Peng; Zhang, Tong-Cun

    2015-01-01

    Mesenchymal stem cells (MSCs) are known to undergo endothelial differentiation in response to treatment with vascular endothelial growth factor (VEGF), but their angiogenic ability is poorly characterized. In the present study, we aimed to further investigate the role of Rho/MRTF-A in angiogenesis by MSCs and the effect of the Rho/MRTF-A pathway on the expression of integrins α1β1 and α5β1, which are known to mediate physiological and pathological angiogenesis. Our results showed that increased expression of α1, α5, and β1 was observed during angiogenesis of differentiated MSCs, and the Rho/MRTF-A signaling pathway was demonstrated to be involved in regulating the expression of integrins α1, α5, and β1. Luciferase reporter assay and ChIP assay determined that MRTF-A could bind to and transactivate the integrin α1 and α5 promoters. Treatment with the Rho inhibitor C3 transferase, the Rho-associated protein kinase (ROCK) inhibitor Y27632 or with shMRTF-A inhibited both the upregulation of α1, α5, and β1 as well as angiogenesis. Furthermore, in human umbilical vein endothelial cells (HUVECs), MRTF-A deletion led to marked reductions in cell migration and vessel network formation compared with the control. These data demonstrate that Rho/MRTF-A signaling is an important mediator that controls integrin gene expression during MSC-mediated angiogenic processes. PMID:25949242

  14. Computer vision profiling of neurite outgrowth dynamics reveals spatiotemporal modularity of Rho GTPase signaling.

    PubMed

    Fusco, Ludovico; Lefort, Riwal; Smith, Kevin; Benmansour, Fethallah; Gonzalez, German; Barillari, Caterina; Rinn, Bernd; Fleuret, Francois; Fua, Pascal; Pertz, Olivier

    2016-01-01

    Rho guanosine triphosphatases (GTPases) control the cytoskeletal dynamics that power neurite outgrowth. This process consists of dynamic neurite initiation, elongation, retraction, and branching cycles that are likely to be regulated by specific spatiotemporal signaling networks, which cannot be resolved with static, steady-state assays. We present NeuriteTracker, a computer-vision approach to automatically segment and track neuronal morphodynamics in time-lapse datasets. Feature extraction then quantifies dynamic neurite outgrowth phenotypes. We identify a set of stereotypic neurite outgrowth morphodynamic behaviors in a cultured neuronal cell system. Systematic RNA interference perturbation of a Rho GTPase interactome consisting of 219 proteins reveals a limited set of morphodynamic phenotypes. As proof of concept, we show that loss of function of two distinct RhoA-specific GTPase-activating proteins (GAPs) leads to opposite neurite outgrowth phenotypes. Imaging of RhoA activation dynamics indicates that both GAPs regulate different spatiotemporal Rho GTPase pools, with distinct functions. Our results provide a starting point to dissect spatiotemporal Rho GTPase signaling networks that regulate neurite outgrowth. PMID:26728857

  15. The Role of Rho GTPases in Toxicity of Clostridium difficile Toxins

    PubMed Central

    Chen, Shuyi; Sun, Chunli; Wang, Haiying; Wang, Jufang

    2015-01-01

    Clostridium difficile (C. difficile) is the main cause of antibiotic-associated diarrhea prevailing in hospital settings. In the past decade, the morbidity and mortality of C. difficile infection (CDI) has increased significantly due to the emergence of hypervirulent strains. Toxin A (TcdA) and toxin B (TcdB), the two exotoxins of C. difficile, are the major virulence factors of CDI. The common mode of action of TcdA and TcdB is elicited by specific glucosylation of Rho-GTPase proteins in the host cytosol using UDP-glucose as a co-substrate, resulting in the inactivation of Rho proteins. Rho proteins are the key members in many biological processes and signaling pathways, inactivation of which leads to cytopathic and cytotoxic effects and immune responses of the host cells. It is supposed that Rho GTPases play an important role in the toxicity of C. difficile toxins. This review focuses on recent progresses in the understanding of functional consequences of Rho GTPases glucosylation induced by C. difficile toxins and the role of Rho GTPases in the toxicity of TcdA and TcdB. PMID:26633511

  16. Focal Adhesion Kinase regulates cell-cell contact formation in epithelial cells via modulation of Rho

    SciTech Connect

    Playford, Martin P.; Vadali, Kavita; Cai Xinming; Burridge, Keith; Schaller, Michael D.

    2008-10-15

    Focal Adhesion Kinase (FAK) is a non-receptor tyrosine kinase that plays a key role in cellular processes such as cell adhesion, migration, proliferation and survival. Recent studies have also implicated FAK in the regulation of cell-cell adhesion. Here, evidence is presented showing that siRNA-mediated suppression of FAK levels in NBT-II cells and expression of dominant negative mutants of FAK caused loss of epithelial cell morphology and inhibited the formation of cell-cell adhesions. Rac and Rho have been implicated in the regulation of cell-cell adhesions and can be regulated by FAK signaling. Expression of active Rac or Rho in NBT-II cells disrupted formation of cell-cell contacts, thus promoting a phenotype similar to FAK-depleted cells. The loss of intercellular contacts in FAK-depleted cells is prevented upon expression of a dominant negative Rho mutant, but not a dominant negative Rac mutant. Inhibition of FAK decreased tyrosine phosphorylation of p190RhoGAP and elevated the level of GTP-bound Rho. This suggests that FAK regulates cell-cell contact formation by regulation of Rho.

  17. Extracting Diffusive States of Rho GTPase in Live Cells: Towards In Vivo Biochemistry

    PubMed Central

    Sabanaygam, Chandran R.; van Golen, Kenneth L.; Mochrie, Simon G. J.

    2015-01-01

    Resolving distinct biochemical interaction states when analyzing the trajectories of diffusing proteins in live cells on an individual basis remains challenging because of the limited statistics provided by the relatively short trajectories available experimentally. Here, we introduce a novel, machine-learning based classification methodology, which we call perturbation expectation-maximization (pEM), that simultaneously analyzes a population of protein trajectories to uncover the system of diffusive behaviors which collectively result from distinct biochemical interactions. We validate the performance of pEM in silico and demonstrate that pEM is capable of uncovering the proper number of underlying diffusive states with an accurate characterization of their diffusion properties. We then apply pEM to experimental protein trajectories of Rho GTPases, an integral regulator of cytoskeletal dynamics and cellular homeostasis, in vivo via single particle tracking photo-activated localization microcopy. Remarkably, pEM uncovers 6 distinct diffusive states conserved across various Rho GTPase family members. The variability across family members in the propensities for each diffusive state reveals non-redundant roles in the activation states of RhoA and RhoC. In a resting cell, our results support a model where RhoA is constantly cycling between activation states, with an imbalance of rates favoring an inactive state. RhoC, on the other hand, remains predominantly inactive. PMID:26512894

  18. Model of Rho-Mediated Myosin Recruitment to the Cleavage Furrow during Cytokinesis

    NASA Astrophysics Data System (ADS)

    Veksler, Alexander; Vavylonis, Dimitrios

    2010-03-01

    The formation and constriction of the contractile ring during cytokinesis, the final step of cell division, depends on the recruitment of motor protein myosin to the cell's equatorial region. During cytokinesis, the myosin attached to the cell's cortex progressively disassembles at the flanking regions and concentrates in the equator [1]. This recruitment depends on myosin motor activity and activation by Rho proteins. Central spindle and astral microtubules establish a spatial pattern of differential Rho activity [2]. We propose a reaction-diffusion model for the dynamics of myosin and Rho proteins during cytokinesis. In the model, the mitotic spindle activates Rho at the equator. Active Rho promotes, in a switch-like manner, myosin assembly into cortical minifilaments. Mechanical stress by cortical myosin causes disassembly of myosin minifilaments and deactivates Rho. Our results explain both the recruitment of myosin to the cleavage furrow and the observed damped myosin oscillations in the cell's flanking regions [1]. Spatial extent, period and decay rate of myosin oscillations are calculated. Various regimes of myosin recruitment are predicted. [1] Zhou & Wang, Mol. Biol. Cell 19:318 (2008) [2] Murthy & Wadsworth, J. Cell Sci. 121:2350 (2008)

  19. Elevated Intraocular Pressure Induces Rho GTPase Mediated Contractile Signaling in the Trabecular Meshwork

    PubMed Central

    Pattabiraman, Padmanabhan P; Inoue, Toshihiro; Rao, P. Vasantha

    2015-01-01

    Rho GTPase regulated contractile signaling in the trabecular meshwork (TM) has been shown to modulate aqueous humor (AH) outflow and intraocular pressure (IOP). To explore whether elevated IOP, a major risk factor for primary open angle glaucoma (POAG) influences Rho GTPase signaling in the TM, we recorded AH outflow in enucleated contralateral porcine eyes perfused for 4–5 hours at either 15 mm or 50 mm Hg pressure. After perfusion, TM tissue extracted from perfused eyes was evaluated for the activation status of Rho GTPase, myosin light chain (MLC), myosin phosphatase target substrate 1 (MYPT1), myristoylated alanine-rich C-kinase substrate (MARCKS) and paxillin. Eyes perfused at 50 mm Hg exhibited a significant decrease in AH outflow facility compared with those perfused at 15 mm Hg. Additionally, TM tissue from eyes perfused at 50 mm Hg revealed significantly increased levels of activated RhoA and phosphorylated MLC, MYPT1, MARCKS and paxillin compared to TM tissue derived from eyes perfused at 15 mm Hg. Taken together, these observations indicate that elevated IOP-induced activation of Rho GTPase-dependent contractile signaling in the TM is associated with increased resistance to AH outflow through the trabecular pathway, and demonstrate the sensitivity of Rho GTPase signaling to mechanical force in the AH outflow pathway. PMID:25956210

  20. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation

    PubMed Central

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia; Tenzer, Stefan; Amann, Kerstin; Billmeier, Ulrike; Atreya, Raja; Fiorino, Gionata; Vetrano, Stefania; Danese, Silvio; Ekici, Arif B.; Wirtz, Stefan; Thonn, Veronika; Watson, Alastair J.M.; Brakebusch, Cord; Bergö, Martin; Neurath, Markus F.; Atreya, Imke

    2016-01-01

    Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I–deficient IECs, our findings suggest new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients. PMID:26752649

  1. Rho-A prenylation and signaling link epithelial homeostasis to intestinal inflammation.

    PubMed

    López-Posadas, Rocío; Becker, Christoph; Günther, Claudia; Tenzer, Stefan; Amann, Kerstin; Billmeier, Ulrike; Atreya, Raja; Fiorino, Gionata; Vetrano, Stefania; Danese, Silvio; Ekici, Arif B; Wirtz, Stefan; Thonn, Veronika; Watson, Alastair J M; Brakebusch, Cord; Bergö, Martin; Neurath, Markus F; Atreya, Imke

    2016-02-01

    Although defects in intestinal barrier function are a key pathogenic factor in patients with inflammatory bowel diseases (IBDs), the molecular pathways driving disease-specific alterations of intestinal epithelial cells (IECs) are largely unknown. Here, we addressed this issue by characterizing the transcriptome of IECs from IBD patients using a genome-wide approach. We observed disease-specific alterations in IECs with markedly impaired Rho-A signaling in active IBD patients. Localization of epithelial Rho-A was shifted to the cytosol in IBDs, and inflammation was associated with suppressed Rho-A activation due to reduced expression of the Rho-A prenylation enzyme geranylgeranyltransferase-I (GGTase-I). Functionally, we found that mice with conditional loss of Rhoa or the gene encoding GGTase-I, Pggt1b, in IECs exhibit spontaneous chronic intestinal inflammation with accumulation of granulocytes and CD4+ T cells. This phenotype was associated with cytoskeleton rearrangement and aberrant cell shedding, ultimately leading to loss of epithelial integrity and subsequent inflammation. These findings uncover deficient prenylation of Rho-A as a key player in the pathogenesis of IBDs. As therapeutic triggering of Rho-A signaling suppressed intestinal inflammation in mice with GGTase-I-deficient IECs, our findings suggest new avenues for treatment of epithelial injury and mucosal inflammation in IBD patients. PMID:26752649

  2. Rho GTPase activity in the honey bee mushroom bodies is correlated with age and foraging experience

    PubMed Central

    Dobrin, Scott E.; Fahrbach, Susan E.

    2011-01-01

    Foraging experience is correlated with structural plasticity of the mushroom bodies of the honey bee brain. While several neurotransmitter and intracellular signaling pathways have been previously implicated as mediators of these structural changes, none interact directly with the cytoskeleton, the ultimate effector of changes in neuronal morphology. The Rho family of GTPases are small, monomeric G proteins that, when activated, initiate a signaling cascade that reorganizes the neuronal cytoskeleton. In this study, we measured activity of two members of the Rho family of GTPases, Rac and RhoA, in the mushroom bodies of bees with different durations of foraging experience. A transient increase in Rac activity coupled with a transient decrease in RhoA activity was found in honey bees with 4 days foraging experience compared with same-aged new foragers. These observations are in accord with previous reports based on studies of other species of a growth supporting role for Rac and a growth opposing role for RhoA. This is the first report of Rho GTPase activation in the honey bee brain. PMID:22108023

  3. Rho/ROCK signaling in motility and metastasis of gastric cancer

    PubMed Central

    Matsuoka, Tasuku; Yashiro, Masakazu

    2014-01-01

    Gastric cancer is one of the most frequent and lethal malignancies worldwide because of high frequency of metastasis. Tumor cell motility and invasion play fundamental roles in cancer metastasis. Recent studies have revealed that the Rho/Rho-associated protein kinases (ROCK) pathway plays a critical role in the regulation of cancer cell motility and invasion. In addition, the Rho/ROCK pathway plays important roles in invasion and metastasis on the basis of its predominant function of cell cytoskeletal regulation in gastric cancer. According to the current understanding of tumor motility, there are two modes of tumor cell movement: mesenchymal and amoeboid. In addition, cancer cell movement can be interchangeable between the mesenchymal and amoeboid movements under certain conditions. Control of cell motility through the actin cytoskeleton creates the potential for regulating tumor cell metastasis. In this review we discuss Rho GTPases and ROCK signaling and describe the mechanisms of Rho/ROCK activity with regard to motility and metastasis in gastric cancer. In addition, we provide an insight of the therapeutic potential of targeting the Rho/ROCK pathway. PMID:25320513

  4. Regulation of amino acid transport in Escherichia coli by transcription termination factor rho.

    PubMed Central

    Quay, S C; Oxender, D L

    1977-01-01

    Amino acid transport rates and amino acid binding proteins were examined in a strain containing the rho-120 mutation (formerly SuA), which has been shown to lower the rho-dependent, ribonucleic acid-activated adenosine triphosphatase activity to 9% of the rho activity in the isogenic wild-type strain. Tryptophan and proline transport, which occur by membrane-bound systems, were not altered. On the other hand, arginine, histidine, leucine, isoleucine, and valine transport were variably increased by a factor of 1.4 to 5.0. Kinetics of leucine transport showed that the LIV (leucine, isoleucine, and valine)-I (binding protein-associated) transport system is increased 8.5-fold, whereas the LIV-II (membrane-bound) system is increased 1.5-fold in the rho mutant under leucine-limited growth conditions. The leucine binding protein is increased fourfold under the same growth conditions. The difference in leucine transport in these strains was greatest during leucine-limited growth; growth on complex media repressed both strains to the same transport activity. We propose that rho-dependent transcriptional termination is important for leucine-specific repression of branched-chain amino acid transport, although rho-independent regulation, presumably by a corepressor-aporepressor-type mechanism, must also occur. PMID:324970

  5. Computer vision profiling of neurite outgrowth dynamics reveals spatiotemporal modularity of Rho GTPase signaling

    PubMed Central

    Fusco, Ludovico; Lefort, Riwal; Smith, Kevin; Benmansour, Fethallah; Gonzalez, German; Barillari, Caterina; Rinn, Bernd; Fleuret, Francois; Fua, Pascal

    2016-01-01

    Rho guanosine triphosphatases (GTPases) control the cytoskeletal dynamics that power neurite outgrowth. This process consists of dynamic neurite initiation, elongation, retraction, and branching cycles that are likely to be regulated by specific spatiotemporal signaling networks, which cannot be resolved with static, steady-state assays. We present NeuriteTracker, a computer-vision approach to automatically segment and track neuronal morphodynamics in time-lapse datasets. Feature extraction then quantifies dynamic neurite outgrowth phenotypes. We identify a set of stereotypic neurite outgrowth morphodynamic behaviors in a cultured neuronal cell system. Systematic RNA interference perturbation of a Rho GTPase interactome consisting of 219 proteins reveals a limited set of morphodynamic phenotypes. As proof of concept, we show that loss of function of two distinct RhoA-specific GTPase-activating proteins (GAPs) leads to opposite neurite outgrowth phenotypes. Imaging of RhoA activation dynamics indicates that both GAPs regulate different spatiotemporal Rho GTPase pools, with distinct functions. Our results provide a starting point to dissect spatiotemporal Rho GTPase signaling networks that regulate neurite outgrowth. PMID:26728857

  6. Ameloblasts require active RhoA to generate normal dental enamel

    PubMed Central

    Li, Yong; Xue, Hui; Everett, Eric T.; Ryan, Kathleen; Peng, Li; Porecha, Rakhee; Yan, Yan; Lucchese, Anna M.; Kuehl, Melissa A.; Pugach, Megan K.; Bouchard, Jessica; Gibson, Carolyn W.

    2013-01-01

    RhoA plays a fundamental role in regulation of the actin cytoskeleton, intercellular attachment and cell proliferation. During amelogenesis, ameloblasts which produce the enamel proteins undergo dramatic cytoskeletal changes and RhoA protein level is upregulated. Transgenic mice were generated that express a dominant-negative RhoA transgene in ameloblasts using amelogenin gene regulatory sequences. Transgenic and WT molar tooth germs were incubated with NaF or NaCl in organ culture. F-actin stained with phalloidin was elevated significantly in WT ameloblasts treated with NaF compared to WT ameloblasts treated with NaCl or compared to transgenic ameloblasts treated with NaF, thereby confirming a block in the RhoA/ROCK pathway in the transgenic mice. Little difference in quantitative fluorescence (estimation of fluorosis) was observed between WT and transgenic incisors from mice provided NaF in their drinking water. We subsequently found reduced transgene expression in incisors compared to molars. Transgenic molar teeth had reduced amelogenin, E-cadherin and Ki67 compared to WT. Hypoplastic enamel in transgenic mice correlates with reduced expression of the enamel protein amelogenin, and E-cadherin and cell proliferation are regulated by RhoA in other tissues. Together these findings reveal deficits in molar ameloblast function when RhoA activity is inhibited. PMID:23841780

  7. RhoA Regulates Peroxisome Association to Microtubules and the Actin Cytoskeleton

    PubMed Central

    Lay, Dorothee; Wiese, Sebastian; Meyer, Helmut E.; Warscheid, Bettina; Saffrich, Rainer; Peränen, Johan; Gorgas, Karin; Just, Wilhelm W.

    2010-01-01

    The current view of peroxisome inheritance provides for the formation of new peroxisomes by both budding from the endoplasmic reticulum and autonomous division. Here we investigate peroxisome-cytoskeleton interactions and show by proteomics, biochemical and immunofluorescence analyses that actin, non-muscle myosin IIA (NMM IIA), RhoA, Rho kinase II (ROCKII) and Rab8 associate with peroxisomes. Our data provide evidence that (i) RhoA in its inactive state, maintained for example by C. botulinum toxin exoenzyme C3, dissociates from peroxisomes enabling microtubule-based peroxisomal movements and (ii) dominant-active RhoA targets to peroxisomes, uncouples the organelles from microtubules and favors Rho kinase recruitment to peroxisomes. We suggest that ROCKII activates NMM IIA mediating local peroxisomal constrictions. Although our understanding of peroxisome-cytoskeleton interactions is still incomplete, a picture is emerging demonstrating alternate RhoA-dependent association of peroxisomes to the microtubular and actin cytoskeleton. Whereas association of peroxisomes to microtubules clearly serves bidirectional, long-range saltatory movements, peroxisome-acto-myosin interactions may support biogenetic functions balancing peroxisome size, shape, number, and clustering. PMID:21079737

  8. WGEF activates Rho in the Wnt–PCP pathway and controls convergent extension in Xenopus gastrulation

    PubMed Central

    Tanegashima, Kosuke; Zhao, Hui; Dawid, Igor B

    2008-01-01

    The Wnt–PCP (planar cell polarity, PCP) pathway regulates cell polarity and convergent extension movements during axis formation in vertebrates by activation of Rho and Rac, leading to the re-organization of the actin cytoskeleton. Rho and Rac activation require guanine nucleotide-exchange factors (GEFs), but the identity of the GEF involved in Wnt–PCP-mediated convergent extension is unknown. Here we report the identification of the weak-similarity GEF (WGEF) gene by a microarray-based screen for notochord enriched genes, and show that WGEF is involved in Wnt-regulated convergent extension. Overexpression of WGEF activated RhoA and rescued the suppression of convergent extension by dominant-negative Wnt-11, whereas depletion of WGEF led to suppression of convergent extension that could be rescued by RhoA or Rho-associated kinase activation. WGEF protein preferentially localized at the plasma membrane, and Frizzled-7 induced colocalization of Dishevelled and WGEF. WGEF protein can bind to Dishevelled and Daam-1, and deletion of the Dishevelled-binding domain generates a hyperactive from of WGEF. These results indicate that WGEF is a component of the Wnt–PCP pathway that connects Dishevelled to Rho activation. PMID:18256687

  9. WGEF activates Rho in the Wnt-PCP pathway and controls convergent extension in Xenopus gastrulation.

    PubMed

    Tanegashima, Kosuke; Zhao, Hui; Dawid, Igor B

    2008-02-20

    The Wnt-PCP (planar cell polarity, PCP) pathway regulates cell polarity and convergent extension movements during axis formation in vertebrates by activation of Rho and Rac, leading to the re-organization of the actin cytoskeleton. Rho and Rac activation require guanine nucleotide-exchange factors (GEFs), but the identity of the GEF involved in Wnt-PCP-mediated convergent extension is unknown. Here we report the identification of the weak-similarity GEF (WGEF) gene by a microarray-based screen for notochord enriched genes, and show that WGEF is involved in Wnt-regulated convergent extension. Overexpression of WGEF activated RhoA and rescued the suppression of convergent extension by dominant-negative Wnt-11, whereas depletion of WGEF led to suppression of convergent extension that could be rescued by RhoA or Rho-associated kinase activation. WGEF protein preferentially localized at the plasma membrane, and Frizzled-7 induced colocalization of Dishevelled and WGEF. WGEF protein can bind to Dishevelled and Daam-1, and deletion of the Dishevelled-binding domain generates a hyperactive from of WGEF. These results indicate that WGEF is a component of the Wnt-PCP pathway that connects Dishevelled to Rho activation. PMID:18256687

  10. Formin-like2 regulates Rho/ROCK pathway to promote actin assembly and cell invasion of colorectal cancer

    PubMed Central

    Zeng, Yuanfeng; Xie, Huijun; Qiao, Yudan; Wang, Jianmei; Zhu, Xiling; He, Guoyang; Li, Yuling; Ren, Xiaoli; Wang, Feifei; Liang, Li; Ding, Yanqing

    2015-01-01

    Formin-like2 (FMNL2) is a member of the diaphanous-related formins family, which act as effectors and upstream modulators of Rho GTPases signaling and control the actin-dependent processes, such as cell motility or invasion. FMNL2 has been identified as promoting the motility and metastasis in colorectal carcinoma (CRC). However, whether FMNL2 regulates Rho signaling to promote cancer cell invasion remains unclear. In this study, we demonstrated an essential role for FMNL2 in the activations of Rho/ROCK pathway, SRF transcription or actin assembly, and subsequent CRC cell invasion. FMNL2 could activate Rho/ROCK pathway, and required ROCK to promote CRC cell invasion. Moreover, FMNL2 promoted the formation of filopodia and stress fiber, and activated the SRF transcription in a Rho-dependent manner. We also demonstrated that FMNL2 was necessary for LPA-induced invasion, RhoA/ROCK activation, actin assembly and SRF activation. FMNL2 was an essential component of LPA signal transduction toward RhoA by directly interacting with LARG. LARG silence inhibited RhoA/ROCK pathway and CRC cell invasion. Collectively, these data indicate that FMNL2, acting as upstream of RhoA by interacting with LARG, can promote actin assembly and CRC cell invasion through a Rho/ROCK-dependent mechanism. PMID:26258642

  11. N-terminus-mediated dimerization of ROCK-I is required for RhoE binding and actin reorganization.

    PubMed

    Garg, Ritu; Riento, Kirsi; Keep, Nicholas; Morris, Jonathan D H; Ridley, Anne J

    2008-04-15

    ROCK-I (Rho-associated kinase 1) is a serine/threonine kinase that can be activated by RhoA and inhibited by RhoE. ROCK-I has an N-terminal kinase domain, a central coiled-coil region and a RhoA-binding domain near the C-terminus. We have previously shown that RhoE binds to the N-terminal 420 amino acids of ROCK-I, which includes the kinase domain as well as N-terminal and C-terminal extensions. In the present study, we show that N-terminus-mediated dimerization of ROCK-I is required for RhoE binding. The central coiled-coil domain can also dimerize ROCK-I in cells, but this is insufficient in the absence of the N-terminus to allow RhoE binding. The kinase activity of ROCK-I(1-420) is required for dimerization and RhoE binding; however, inclusion of part of the coiled-coil domain compensates for lack of kinase activity, allowing RhoE to bind. N-terminus-mediated dimerization is also required for ROCK-I to induce the formation of stellate actin stress fibres in cells. These results indicate that dimerization via the N-terminus is critical for ROCK-I function in cells and for its regulation by RhoE. PMID:18215121

  12. TrkB-T1 regulates the RhoA signaling and actin cytoskeleton in glioma cells

    SciTech Connect

    Ohira, Koji; Homma, Koichi J.; Hirai, Hirohisa; Nakamura, Shun; Hayashi, Motoharu . E-mail: hayashi@pri.kyoto-u.ac.jp

    2006-04-14

    Recently, the truncated TrkB receptor, T1, has been reported to be involved in the control of cell morphology via the regulation of Rho proteins, through which T1 binds Rho guanine nucleotide dissociation inhibitor (Rho GDI) 1 and dissociates it in a brain-derived neurotrophic factor (BDNF)-dependent manner. However, it is unclear whether T1 signaling regulates the downstream of Rho signaling and the actin cytoskeleton. In this study, we investigated this question using C6 rat glioma cells, which express T1 endogenously. Rho GDI1 was dissociated from T1 in a BDNF-dependent manner, which also causes decreases in the activities of Rho-signaling molecules such as RhoA, Rho-associated kinase, p21-activated kinase, and extracellular-signal regulated kinase1/2. Moreover, BDNF treatment resulted in the disappearance of stress fibers in the cells treated with lysophosphatidic acid, an activator of RhoA, and in morphological changes in cells. Furthermore, a competitive assay with cyan fluorescent protein fusion proteins of T1-specific sequences reduced the effects of BDNF. These results suggest that T1 regulates the Rho-signaling pathways and the actin cytoskeleton.

  13. Localization of RHO-4 Indicates Differential Regulation of Conidial versus Vegetative Septation in the Filamentous Fungus Neurospora crassa▿ †

    PubMed Central

    Rasmussen, Carolyn G.; Glass, N. Louise

    2007-01-01

    rho-4 mutants of the filamentous fungus Neurospora crassa lack septa and asexual spores (conidia) and grow slowly. In this report, localization of green fluorescent protein-tagged RHO-4 is used to elucidate the differences in factors controlling RHO-4 localization during vegetative growth versus asexual development. RHO-4 forms a ring at incipient vegetative septation sites that constricts with the formation of the septum toward the septal pore; RHO-4 persists around the septal pore after septum completion. During the formation of conidia, RHO-4 localizes to the primary septum but subsequently is relocalized to the cytoplasm after the placement of the secondary septum. Cytoplasmic localization and inactivation of RHO-4 are mediated by a direct physical interaction with RDI-1, a RHO guanosine nucleotide dissociation inhibitor. Inappropriate activation of the cyclic AMP-dependent protein kinase A pathway during vegetative growth causes mislocalization of RHO-4 away from septa to the cytoplasm, a process which was dependent upon RDI-1. An adenylate cyclase cr-1 mutant partially suppresses the aconidial defect of rho-4 mutants but only rarely suppresses the vegetative septation defect, indicating that conidial septation is negatively regulated by CR-1. These data highlight the differences in the regulation of septation during conidiation versus vegetative septation in filamentous fungi. PMID:17496127

  14. Quantitative characterization of gene regulation by Rho dependent transcription termination.

    PubMed

    Hussein, Razika; Lee, Tiffany Y; Lim, Han N

    2015-08-01

    Rho factor dependent transcription termination (RTT) is common within the coding sequences of bacterial genes and it acts to couple transcription and translation levels. Despite the importance of RTT for gene regulation, its effects on mRNA and protein concentrations have not been quantitatively characterized. Here we demonstrate that the exogenous cfp gene encoding the cyan fluorescent protein can serve as a model for gene regulation by RTT. This was confirmed by showing that Psu and bicyclomycin decrease RTT and increase full length cfp mRNAs (but remarkably they have little effect on protein production). We then use cfp to characterize the relationship between its protein and full length mRNA concentrations when the translation initiation rate is varied by sequence modifications of the translation initiation region (TIR). These experiments reveal that the fold change in protein concentration (RP) and the fold change in full length mRNA concentration (Rm) have the relationship RP≈Rm(b), where b is a constant. The average value of b was determined from three separate data sets to be ~3.6. We demonstrate that the above power law function can predict how altering the translation initiation rate of a gene in an operon will affect the mRNA concentrations of downstream genes and specify a lower bound for the associated changes in protein concentrations. In summary, this study defines a simple phenomenological model to help program expression from single genes and operons that are regulated by RTT, and to guide molecular models of RTT. PMID:25982507

  15. [Alpha1-adrenoceptor subtypes and alpha1-adrenoceptor antagonists].

    PubMed

    Muramatsu, Ikunobu; Suzuki, Fumiko; Tanaka, Takashi; Yamamoto, Hatsumi; Morishima, Shigeru

    2006-03-01

    Alpha(1)-adrenoceptors are widely distributed in the human body and play important physiologic roles. Three alpha(1)-adrenoceptor subtypes (alpha(1A), alpha(1B) and alpha(1D)) have been cloned and show different pharmacologic profiles. In addition, a putative alpha(1)-adrenoceptor (alpha(1L) subtype) has also been proposed. Recently, three drugs (tamsulosin, naftopidil, and silodosin) have been developed in Japan for the treatment of urinary obstruction in patients with benign prostatic hyperplasia. In this review, we describe recent alpha(1)-adrenoceptor subclassifications and the pharmacologic characteristics (subtype selectivity and clinical relevance) of alpha(1)-adrenoceptor antagonists. PMID:16518082

  16. E1AF/PEA3 activates the Rho/Rho-associated kinase pathway to increase the malignancy potential of non-small-cell lung cancer cells.

    PubMed

    Hakuma, Nobuyuki; Kinoshita, Ichiro; Shimizu, Yasushi; Yamazaki, Koichi; Yoshida, Koichi; Nishimura, Masaharu; Dosaka-Akita, Hirotoshi

    2005-12-01

    E1AF/PEA3, an Ets family transcription factor, is frequently overexpressed in non-small-cell lung cancers (NSCLCs). Overexpression of E1AF increases motility and invasion of VMRC-LCD and NCI-H226 NSCLC cells, which lack endogenous E1AF expression, and the effect is synergistically increased by hepatocyte growth factor (HGF). The small GTPase Rho/Rho-associated kinase (ROCK) pathway is also involved in motility and invasion. To determine the role of the Rho/ROCK pathway in malignant phenotypes induced by E1AF, we analyzed VMRC-LCD cells transfected with an E1AF expression vector (LCD-E1AF cells) or with empty vector (LCD-vector cells). LCD-E1AF cells had more GTP-bound (active) Rho than LCD-vector cells and Rho activation was synergistically increased by HGF. The Rho activation by E1AF and HGF was also shown in NCI-H226 cells. Phosphorylation of myosin light chain (MLC), a downstream effector of ROCK signaling, was higher in LCD-E1AF cells than in LCD-vector cells, especially under HGF treatment. A specific ROCK inhibitor, Y27632, strongly suppressed MLC phosphorylation, cell motility, and invasion. In nude mice implanted s.c. and intrapulmonarily, LCD-E1AF cells made more local tumors than LCD-vector cells (six of six versus one of seven mice and four of seven versus one of seven mice, respectively). Three of the four mice with lung tumors from LCD-E1AF cells had lymph node metastases whereas the mouse with LCD-vector tumors did not. LCD-E1AF tumors showed higher MLC phosphorylation than LCD-vector tumors. These results suggest that E1AF activates the Rho/ROCK pathway in an HGF-enhanced manner and its activation is important in E1AF-induced motility and invasion as well as tumorigenesis and metastasis in NSCLC cells. PMID:16322223

  17. TrkBT1 Induces Liver Metastasis of Pancreatic Cancer Cells by Sequestering Rho GDP Dissociation Inhibitor and Promoting RhoA Activation

    PubMed Central

    Li, Zhongkui; Chang, Zhe; Chiao, Lucia J.; Kang, Ya’an; Xia, Qianghua; Zhu, Cihui; Fleming, Jason B.; Evans, Douglas B.; Chiao, Paul J.

    2011-01-01

    Many genetic and molecular alterations, such as K-ras mutation and NF-κB activation, have been identified in pancreatic cancer. However, the mechanisms by which pancreatic cancer metastasizes still remain to be determined. Although we previously showed that the tropomyosin-related kinase B (TrkB) was significantly correlated with the development of liver metastasis, its function in pancreatic cancer metastasis remained unresolved. In the present study, we showed that overexpressed TrkB is an alternatively spliced transcript variant of TrkB (TrkBT1) with a unique COOH-terminal 12–amino acid sequence and is mainly localized in the cytoplasm. Our results showed that overexpression of Flag-tagged TrkBT1 but not a Flag-tagged TrkBT1 COOH-terminal deletion mutant (Flag-TrkBT1ΔC) in nonmetastatic pancreatic cancer cells enhanced cell proliferation, promoted formation of colonies in soft agar, stimulated tumor cell invasion, and induced liver metastasis in an orthotopic xenograft mouse model of pancreatic cancer. TrkBT1 interacted with Rho GDP dissociation inhibitor (GDI) in vivo, but Flag-TrkBT1ΔC did not. Furthermore, overexpression of Flag-TrkBT1 and knockdown of RhoGDI expression by RhoGDI short hairpin RNAs promoted RhoA activation, but Flag-TrkBT1ΔC overexpression did not. Therefore, our results showed that TrkBT1 overexpression induces liver metastasis of pancreatic cancer and uncovered a unique signaling mechanism by which TrkBT1 sequesters GDI and activates RhoA signaling. PMID:19773448

  18. Mycobacterium tuberculosis Rho Is an NTPase with Distinct Kinetic Properties and a Novel RNA-Binding Subdomain

    PubMed Central

    Mitra, Anirban; Misquitta, Rachel; Nagaraja, Valakunja

    2014-01-01

    Two mechanisms – factor independent and dependent termination – ensure the completion of RNA synthesis in eubacteria. Factor-dependent mechanism relies on the Rho protein to terminate transcription by interacting with RNA polymerase. Although well studied in Escherichia coli, the properties of the Rho homologs from most bacteria are not known. The rho gene is unusually large in genus Mycobacterium and other members of actinobacteria, having ∼150 additional residues towards the amino terminal end. We describe the distinct properties of Rho from Mycobacterium tuberculosis. It is an NTPase with a preference for purine nucleoside triphosphates with kinetic properties different from E. coli homolog and an ability to use various RNA substrates. The N-terminal subdomain of MtbRho can bind to RNA by itself, and appears to contribute to the interaction of the termination factor with RNAs. Furthermore, the interaction with RNA induces changes in conformation and oligomerization of MtbRho. PMID:25229539

  19. Activator-inhibitor coupling between Rho signaling and actin assembly make the cell cortex an excitable medium

    PubMed Central

    Bement, William M.; Leda, Marcin; Moe, Alison M.; Kita, Angela M.; Larson, Matthew E.; Golding, Adriana E.; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L.; Goryachev, Andrew B.; von Dassow, George

    2016-01-01

    Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, while Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modeling results show that waves represent excitable dynamics of a reaction diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

  20. Activator-inhibitor coupling between Rho signalling and actin assembly makes the cell cortex an excitable medium.

    PubMed

    Bement, William M; Leda, Marcin; Moe, Alison M; Kita, Angela M; Larson, Matthew E; Golding, Adriana E; Pfeuti, Courtney; Su, Kuan-Chung; Miller, Ann L; Goryachev, Andrew B; von Dassow, George

    2015-11-01

    Animal cell cytokinesis results from patterned activation of the small GTPase Rho, which directs assembly of actomyosin in the equatorial cortex. Cytokinesis is restricted to a portion of the cell cycle following anaphase onset in which the cortex is responsive to signals from the spindle. We show that shortly after anaphase onset oocytes and embryonic cells of frogs and echinoderms exhibit cortical waves of Rho activity and F-actin polymerization. The waves are modulated by cyclin-dependent kinase 1 (Cdk1) activity and require the Rho GEF (guanine nucleotide exchange factor), Ect2. Surprisingly, during wave propagation, although Rho activity elicits F-actin assembly, F-actin subsequently inactivates Rho. Experimental and modelling results show that waves represent excitable dynamics of a reaction-diffusion system with Rho as the activator and F-actin the inhibitor. We propose that cortical excitability explains fundamental features of cytokinesis including its cell cycle regulation. PMID:26479320

  1. Amphetamine activates Rho GTPase signaling to mediate dopamine transporter internalization and acute behavioral effects of amphetamine.

    PubMed

    Wheeler, David S; Underhill, Suzanne M; Stolz, Donna B; Murdoch, Geoffrey H; Thiels, Edda; Romero, Guillermo; Amara, Susan G

    2015-12-22

    Acute amphetamine (AMPH) exposure elevates extracellular dopamine through a variety of mechanisms that include inhibition of dopamine reuptake, depletion of vesicular stores, and facilitation of dopamine efflux across the plasma membrane. Recent work has shown that the DAT substrate AMPH, unlike cocaine and other nontransported blockers, can also stimulate endocytosis of the plasma membrane dopamine transporter (DAT). Here, we show that when AMPH enters the cytoplasm it rapidly stimulates DAT internalization through a dynamin-dependent, clathrin-independent process. This effect, which can be observed in transfected cells, cultured dopamine neurons, and midbrain slices, is mediated by activation of the small GTPase RhoA. Inhibition of RhoA activity with C3 exotoxin or a dominant-negative RhoA blocks AMPH-induced DAT internalization. These actions depend on AMPH entry into the cell and are blocked by the DAT inhibitor cocaine. AMPH also stimulates cAMP accumulation and PKA-dependent inactivation of RhoA, thus providing a mechanism whereby PKA- and RhoA-dependent signaling pathways can interact to regulate the timing and robustness of AMPH's effects on DAT internalization. Consistent with this model, the activation of D1/D5 receptors that couple to PKA in dopamine neurons antagonizes RhoA activation, DAT internalization, and hyperlocomotion observed in mice after AMPH treatment. These observations support the existence of an unanticipated intracellular target that mediates the effects of AMPH on RhoA and cAMP signaling and suggest new pathways to target to disrupt AMPH action. PMID:26553986

  2. Amphetamine activates Rho GTPase signaling to mediate dopamine transporter internalization and acute behavioral effects of amphetamine

    PubMed Central

    Wheeler, David S.; Underhill, Suzanne M.; Stolz, Donna B.; Murdoch, Geoffrey H.; Thiels, Edda; Romero, Guillermo; Amara, Susan G.

    2015-01-01

    Acute amphetamine (AMPH) exposure elevates extracellular dopamine through a variety of mechanisms that include inhibition of dopamine reuptake, depletion of vesicular stores, and facilitation of dopamine efflux across the plasma membrane. Recent work has shown that the DAT substrate AMPH, unlike cocaine and other nontransported blockers, can also stimulate endocytosis of the plasma membrane dopamine transporter (DAT). Here, we show that when AMPH enters the cytoplasm it rapidly stimulates DAT internalization through a dynamin-dependent, clathrin-independent process. This effect, which can be observed in transfected cells, cultured dopamine neurons, and midbrain slices, is mediated by activation of the small GTPase RhoA. Inhibition of RhoA activity with C3 exotoxin or a dominant-negative RhoA blocks AMPH-induced DAT internalization. These actions depend on AMPH entry into the cell and are blocked by the DAT inhibitor cocaine. AMPH also stimulates cAMP accumulation and PKA-dependent inactivation of RhoA, thus providing a mechanism whereby PKA- and RhoA-dependent signaling pathways can interact to regulate the timing and robustness of AMPH’s effects on DAT internalization. Consistent with this model, the activation of D1/D5 receptors that couple to PKA in dopamine neurons antagonizes RhoA activation, DAT internalization, and hyperlocomotion observed in mice after AMPH treatment. These observations support the existence of an unanticipated intracellular target that mediates the effects of AMPH on RhoA and cAMP signaling and suggest new pathways to target to disrupt AMPH action. PMID:26553986

  3. WinRho: Rh immune globulin prepared by ion exchange for intravenous use.

    PubMed

    Bowman, J M; Friesen, A D; Pollock, J M; Taylor, W E

    1980-12-01

    An Rh immune globulin [Rh IgG] for intravenous use, WinRho, has been prepared by the Winnipeg Rh Institute by a modification of the ion-exchange column method of Hoppe and colleagues. When administered to Rh-negative male and nonpregnant female volunteers WinRho was found to be nonpyrogenic, nontoxic, safe and protective against Rh alloimmunization. In a clinical trial with 240 microgram given at about 28 weeks' gestation and 120 microgram given after delivery to Rh-negative women at risk of Rh immunization WinRho was effective in preventing Rh immunization. Of the 870 women carrying Rh-positive fetuses who were treated with WinRho during pregnancy and were not tested several months after delivery 14 would have shown evidence of Rh immunization by the time of delivery if WinRho had been ineffective; none showed such evidence. Of the 1122 women carrying Rh-positive fetuses who were retested 4 to 6 months after delivery 83 would have shown evidence of Rh immunization at that time if WinRho had been ineffective; only 1 showed such evidence. The efficiency of yield of anti-D with the modified method of production, the fct that it can be given intravenously (a route that causes the patient less discomfort and immediately results in high anti-D levels) and the lower levels of contaminating IgA and IgM make WinRho the preparation of choice for preventing Rh immunization. PMID:6161687

  4. Enhanced p122RhoGAP/DLC-1 Expression Can Be a Cause of Coronary Spasm

    PubMed Central

    Kinjo, Takahiko; Tanaka, Makoto; Osanai, Tomohiro; Shibutani, Shuji; Narita, Ikuyo; Tanno, Tomohiro; Nishizaki, Kimitaka; Ichikawa, Hiroaki; Kimura, Yoshihiro; Ishida, Yuji; Yokota, Takashi; Shimada, Michiko; Homma, Yoshimi; Tomita, Hirofumi; Okumura, Ken

    2015-01-01

    Background We previously showed that phospholipase C (PLC)-δ1 activity was enhanced by 3-fold in patients with coronary spastic angina (CSA). We also reported that p122Rho GTPase-activating protein/deleted in liver cancer-1 (p122RhoGAP/DLC-1) protein, which was discovered as a PLC-δ1 stimulator, was upregulated in CSA patients. We tested the hypothesis that p122RhoGAP/DLC-1 overexpression causes coronary spasm. Methods and Results We generated transgenic (TG) mice with vascular smooth muscle (VSM)-specific overexpression of p122RhoGAP/DLC-1. The gene and protein expressions of p122RhoGAP/DLC-1 were markedly increased in the aorta of homozygous TG mice. Stronger staining with anti-p122RhoGAP/DLC-1 in the coronary artery was found in TG than in WT mice. PLC activities in the plasma membrane fraction and the whole cell were enhanced by 1.43 and 2.38 times, respectively, in cultured aortic vascular smooth muscle cells from homozygous TG compared with those from WT mice. Immediately after ergometrine injection, ST-segment elevation was observed in 1 of 7 WT (14%), 6 of 7 heterozygous TG (84%), and 7 of 7 homozygous TG mice (100%) (p<0.05, WT versus TGs). In the isolated Langendorff hearts, coronary perfusion pressure was increased after ergometrine in TG, but not in WT mice, despite of the similar response to prostaglandin F2α between TG and WT mice (n = 5). Focal narrowing of the coronary artery after ergometrine was documented only in TG mice. Conclusions VSM-specific overexpression of p122RhoGAP/DLC-1 enhanced coronary vasomotility after ergometrine injection in mice, which is relevant to human CSA. PMID:26624289

  5. WinRho: Rh immune globulin prepared by ion exchange for intravenous use.

    PubMed Central

    Bowman, J M; Friesen, A D; Pollock, J M; Taylor, W E

    1980-01-01

    An Rh immune globulin [Rh IgG] for intravenous use, WinRho, has been prepared by the Winnipeg Rh Institute by a modification of the ion-exchange column method of Hoppe and colleagues. When administered to Rh-negative male and nonpregnant female volunteers WinRho was found to be nonpyrogenic, nontoxic, safe and protective against Rh alloimmunization. In a clinical trial with 240 microgram given at about 28 weeks' gestation and 120 microgram given after delivery to Rh-negative women at risk of Rh immunization WinRho was effective in preventing Rh immunization. Of the 870 women carrying Rh-positive fetuses who were treated with WinRho during pregnancy and were not tested several months after delivery 14 would have shown evidence of Rh immunization by the time of delivery if WinRho had been ineffective; none showed such evidence. Of the 1122 women carrying Rh-positive fetuses who were retested 4 to 6 months after delivery 83 would have shown evidence of Rh immunization at that time if WinRho had been ineffective; only 1 showed such evidence. The efficiency of yield of anti-D with the modified method of production, the fct that it can be given intravenously (a route that causes the patient less discomfort and immediately results in high anti-D levels) and the lower levels of contaminating IgA and IgM make WinRho the preparation of choice for preventing Rh immunization. PMID:6161687

  6. PRL-1 Protein Promotes ERK1/2 and RhoA Protein Activation through a Non-canonical Interaction with the Src Homology 3 Domain of p115 Rho GTPase-activating Protein

    SciTech Connect

    Bai, Yunpeng; Luo, Yong; Liu, Sijiu; Zhang, Lujuan; Shen, Kui; Dong, Yuanshu; Walls, Chad D.; Quilliam, Lawrence A.; Wells, Clark D.; Cao, Youjia; Zhang, Zhong-Yin

    2012-03-15

    Phosphatases of the regenerating liver (PRL) play oncogenic roles in cancer development and metastasis. Although previous studies indicate that PRL-1 promotes cell growth and migration by activating both the ERK1/2 and RhoA pathways, the mechanism by which it activates these signaling events remains unclear. We have identified a PRL-1-binding peptide (Peptide 1) that shares high sequence identity with a conserved motif in the Src homology 3 (SH3) domain of p115 Rho GTPase-activating protein (GAP). p115 RhoGAP directly binds PRL-1 in vitro and in cells via its SH3 domain. Structural analyses of the PRL-1 {center_dot} Peptide 1 complex revealed a novel protein-protein interaction whereby a sequence motif within the PxxP ligand-binding site of the p115 RhoGAP SH3 domain occupies a folded groove within PRL-1. This prevents the canonical interaction between the SH3 domain of p115 RhoGAP and MEKK1 and results in activation of ERK1/2. Furthermore, PRL-1 binding activates RhoA signaling by inhibiting the catalytic activity of p115 RhoGAP. The results demonstrate that PRL-1 binding to p115 RhoGAP provides a coordinated mechanism underlying ERK1/2 and RhoA activation.

  7. A Novel Rho-Like Protein TbRHP Is Involved in Spindle Formation and Mitosis in Trypanosomes

    PubMed Central

    Abbasi, Kanwal; DuBois, Kelly N.; Dacks, Joel B.; Field, Mark C.

    2011-01-01

    Background In animals and fungi Rho subfamily small GTPases are involved in signal transduction, cytoskeletal function and cellular proliferation. These organisms typically possess multiple Rho paralogues and numerous downstream effectors, consistent with the highly complex contributions of Rho proteins to cellular physiology. By contrast, trypanosomatids have a much simpler Rho-signaling system, and the Trypanosoma brucei genome contains only a single divergent Rho-related gene, TbRHP (Tb927.10.6240). Further, only a single RhoGAP-like protein (Tb09.160.4180) is annotated, contrasting with the >70 Rho GAP proteins from Homo sapiens. We wished to establish the function(s) of TbRHP and if Tb09.160.4180 is a potential GAP for this protein. Methods/Findings TbRHP represents an evolutionarily restricted member of the Rho GTPase clade and is likely trypanosomatid restricted. TbRHP is expressed in both mammalian and insect dwelling stages of T. brucei and presents with a diffuse cytoplasmic location and is excluded from the nucleus. RNAi ablation of TbRHP results in major cell cycle defects and accumulation of multi-nucleated cells, coinciding with a loss of detectable mitotic spindles. Using yeast two hybrid analysis we find that TbRHP interacts with both Tb11.01.3180 (TbRACK), a homolog of Rho-kinase, and the sole trypanosome RhoGAP protein Tb09.160.4180, which is related to human OCRL. Conclusions Despite minimization of the Rho pathway, TbRHP retains an important role in spindle formation, and hence mitosis, in trypanosomes. TbRHP is a partner for TbRACK and an OCRL-related trypanosome Rho-GAP. PMID:22096505

  8. RhoB Acts as a Tumor Suppressor That Inhibits Malignancy of Clear Cell Renal Cell Carcinoma.

    PubMed

    Chen, Weihao; Niu, Shaoxi; Ma, Xin; Zhang, Peng; Gao, Yu; Fan, Yang; Pang, Haigang; Gong, Huijie; Shen, Donglai; Gu, Liangyou; Zhang, Yu; Zhang, Xu

    2016-01-01

    This study aims to investigate the biological role of RhoB in clear cell renal cell carcinoma (ccRCC). The expression of RhoB was examined in specimens of patients and cell lines by Western blot and Immunohistochemistry. The correlation between RhoB expression and clinicopathologic variables was also analyzed. The effects of RhoB on cell proliferation, cell cycle, cell apoptosis, and invasion/migration were detected by over-expression and knockdown of RhoB level in ccRCC cells via plasmids and RNAi. The results showed that RhoB was low-expressed in ccRCC surgical specimens and cell lines compared with adjacent normal renal tissues and normal human renal proximal tubular epithelial cell lines (HKC), and its protein expression level was significantly associated with the tumor pathologic parameter embracing tumor size(P = 0.0157), pT stage(P = 0.0035), TNM stage(P = 0.0024) and Fuhrman tumor grade(P = 0.0008). Further, over-expression of RhoB remarkably inhibited the cancer cell proliferation, colony formation and promoted cancer cell apoptosis, and aslo reduced the invasion and migration ability of ccRCC cells. Interestingly, up-regulation of RhoB could induce cell cycle arrest in G2/M phase and led to cell cycle regulators(CyclineB1,CDK1) and pro-apoptotic protein(casp3,casp9) aberrant expression. Moreover, knockdown of RhoB in HKC cells promoted cell proliferation and migration. Taken together, our study indicates that RhoB expression is decreased in ccRCC carcinogenesis and progression. Up-regulation of RhoB significantly inhibits ccRCC cell malignant phenotype. These findings show that RhoB may play a tumor suppressive role in ccRCC cells, raising its potential value in futural therapeutic target for the patients of ccRCC. PMID:27384222

  9. RhoB Acts as a Tumor Suppressor That Inhibits Malignancy of Clear Cell Renal Cell Carcinoma

    PubMed Central

    Ma, Xin; Zhang, Peng; Gao, Yu; Fan, Yang; Pang, Haigang; Gong, Huijie; Shen, Donglai; Gu, Liangyou; Zhang, Yu

    2016-01-01

    This study aims to investigate the biological role of RhoB in clear cell renal cell carcinoma (ccRCC). The expression of RhoB was examined in specimens of patients and cell lines by Western blot and Immunohistochemistry. The correlation between RhoB expression and clinicopathologic variables was also analyzed. The effects of RhoB on cell proliferation, cell cycle, cell apoptosis, and invasion/migration were detected by over-expression and knockdown of RhoB level in ccRCC cells via plasmids and RNAi. The results showed that RhoB was low-expressed in ccRCC surgical specimens and cell lines compared with adjacent normal renal tissues and normal human renal proximal tubular epithelial cell lines (HKC), and its protein expression level was significantly associated with the tumor pathologic parameter embracing tumor size(P = 0.0157), pT stage(P = 0.0035), TNM stage(P = 0.0024) and Fuhrman tumor grade(P = 0.0008). Further, over-expression of RhoB remarkably inhibited the cancer cell proliferation, colony formation and promoted cancer cell apoptosis, and aslo reduced the invasion and migration ability of ccRCC cells. Interestingly, up-regulation of RhoB could induce cell cycle arrest in G2/M phase and led to cell cycle regulators(CyclineB1,CDK1) and pro-apoptotic protein(casp3,casp9) aberrant expression. Moreover, knockdown of RhoB in HKC cells promoted cell proliferation and migration. Taken together, our study indicates that RhoB expression is decreased in ccRCC carcinogenesis and progression. Up-regulation of RhoB significantly inhibits ccRCC cell malignant phenotype. These findings show that RhoB may play a tumor suppressive role in ccRCC cells, raising its potential value in futural therapeutic target for the patients of ccRCC. PMID:27384222

  10. Observation of B^+\\to\\eta\\rho^+ and Search for B^0 Decays to\\eta^\\prime\\eta, \\eta\\pi^0, \\eta^\\prime\\pi^0, and \\omega\\pi^0

    SciTech Connect

    Aubert, Bernard; Bona, Marcella; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Prencipe, E.; Prudent, X.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Lopez, L.; Palano, Antimo; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Abrams, G.S.; Battaglia, Marco; Brown, D.N.; Button-Shafer, Janice; Cahn, Robert N.; /LBL, Berkeley /Birmingham U. /Ruhr U., Bochum /Bristol U. /British Columbia U. /Brunel U. /Novosibirsk, IYF /UC, Irvine /UCLA /UC, Riverside /UC, San Diego /UC, Santa Barbara /UC, Santa Cruz /Caltech /Cincinnati U. /Colorado U. /Colorado State U. /Dortmund U. /Dresden, Tech. U. /Ecole Polytechnique /Edinburgh U. /INFN, Ferrara /Frascati /Genoa U. /INFN, Genoa /Harvard U. /Heidelberg U. /Imperial Coll., London /Iowa U. /Iowa State U. /Johns Hopkins U. /Karlsruhe U. /Orsay, LAL /LLNL, Livermore /Liverpool U. /Queen Mary, U. of London /Royal Holloway, U. of London /Louisville U. /Manchester U. /Maryland U. /Massachusetts U., Amherst /MIT /McGill U. /INFN, Milan /Mississippi U. /Montreal U. /Mt. Holyoke Coll. /INFN, Naples /NIKHEF, Amsterdam /Notre Dame U. /Ohio State U. /Oregon U. /INFN, Padua /Paris U., VI-VII /Pennsylvania U. /INFN, Perugia /INFN, Pisa /Princeton U. /INFN, Rome /Rostock U. /Rutherford /DSM, DAPNIA, Saclay /South Carolina U. /SLAC /Stanford U., Phys. Dept. /SUNY, Albany /Tennessee U. /Texas U. /Texas U., Dallas /INFN, Turin /INFN, Trieste /Valencia U., IFIC /Victoria U. /Warwick U. /Wisconsin U., Madison

    2008-04-22

    The authors present measurements of branching fractions for five B-meson decays to two-body charmless final states. The data, collected with the BABAR detector at the Stanford Linear Accelerator Center, represent 459 million B{bar B} pairs. The results for branching fractions are, in units of 10{sup -6} (upper limits at 90% C.L.): {Beta}(B{sup +} {yields} {eta}{rho}{sup +}) = 9.9 {+-} 1.2 {+-} 0.8, {Beta}(B{sup 0} {yields} {eta}{prime}{eta}) = 0.5 {+-} 0.4 {+-} 0.1 (< 1.2), {Beta}(B{sup 0} {yields} {eta}{pi}{sup 0}) = 0.9 {+-} 0.4 {+-} 0.1 (< 1.5), {Beta}(B{sup 0} {yields} {eta}{prime}{pi}{sup 0}) = 0.9 {+-} 0.4 {+-} 0.1 (< 1.5), and {Beta}(B{sup 0}{sup 0} {yields} {omega}{pi}{sup 0}) = {eta}{rho}{sup +} mode, they measure the charge asymmetry {Alpha}{sub ch} (B{sup +} {yields} {eta}{rho}{sup +}) = 0.13 {+-} 0.11 {+-} 0.02.

  11. RhoC is essential for TGF-{beta}1-induced invasive capacity of rat ascites hepatoma cells

    SciTech Connect

    Mukai, M.; Endo, H.; Iwasaki, T.; Tatsuta, M.; Togawa, A.; Nakamura, H.; Inoue, M. . E-mail: inoue-ma2@mc.pref.osaka.jp

    2006-07-21

    Transforming growth factor-{beta}1 (TGF-{beta}1) is a multifunctional growth factor that plays a role in cell proliferation, differentiation, extracellular matrix production, apoptosis, and cell motility. We show here that TGF-{beta}1 increased the invasiveness of MM1 cells, which are a highly invasive clone of rat ascites hepatoma cells. Both mRNA and protein levels of RhoC but not RhoA in TGF-{beta}1-treated MM1 cells increased. In parallel with this increase in expression, RhoC activity was induced by TGF-{beta}1 treatment. When RhoC was overexpressed in MM1 cells, the invasive capacity increased. The RhoC-overexpressing cells formed more nodules than did mock cells when injected into rat peritoneum. Furthermore, when RhoC expression was reduced by transfection with shRNA/RhoC, the invasiveness of MM1 cells decreased with concomitant suppression of RhoC expression. Thus, the induced expression of RhoC by TGF-{beta}1 in MM1 cells plays a critical role in TGF-{beta}1-induced cell migration.

  12. RhoB Promotes γH2AX Dephosphorylation and DNA Double-Strand Break Repair

    PubMed Central

    Mamouni, Kenza; Cristini, Agnese; Guirouilh-Barbat, Josée; Monferran, Sylvie; Lemarié, Anthony; Faye, Jean-Charles; Lopez, Bernard S.

    2014-01-01

    Unlike other Rho GTPases, RhoB is rapidly induced by DNA damage, and its expression level decreases during cancer progression. Because inefficient repair of DNA double-strand breaks (DSBs) can lead to cancer, we investigated whether camptothecin, an anticancer drug that produces DSBs, induces RhoB expression and examined its role in the camptothecin-induced DNA damage response. We show that in camptothecin-treated cells, DSBs induce RhoB expression by a mechanism that depends notably on Chk2 and its substrate HuR, which binds to RhoB mRNA and protects it against degradation. RhoB-deficient cells fail to dephosphorylate γH2AX following camptothecin removal and show reduced efficiency of DSB repair by homologous recombination. These cells also show decreased activity of protein phosphatase 2A (PP2A), a phosphatase for γH2AX and other DNA damage and repair proteins. Thus, we propose that DSBs activate a Chk2-HuR-RhoB pathway that promotes PP2A-mediated dephosphorylation of γH2AX and DSB repair. Finally, we show that RhoB-deficient cells accumulate endogenous γH2AX and chromosomal abnormalities, suggesting that RhoB loss increases DSB-mediated genomic instability and tumor progression. PMID:24912678

  13. Rho-Associated Kinase Activity Is an Independent Predictor of Cardiovascular Events in Acute Coronary Syndrome

    PubMed Central

    Kajikawa, Masato; Noma, Kensuke; Nakashima, Ayumu; Maruhashi, Tatsuya; Iwamoto, Yumiko; Matsumoto, Takeshi; Iwamoto, Akimichi; Oda, Nozomu; Hidaka, Takayuki; Kihara, Yasuki; Aibara, Yoshiki; Chayama, Kazuaki; Sasaki, Shota; Kato, Masaya; Dote, Keigo; Goto, Chikara; Liao, James K.; Higashi, Yukihito

    2016-01-01

    Rho-associated kinases play an important role in a variety of cellular functions. Although Rho-associated kinase activity has been shown to be an independent predictor for future cardiovascular events in a general population, there is no information on Rho-associated kinase activity in patients with acute coronary syndrome. We evaluated leukocyte Rho-associated kinase activity by Western blot analysis in 73 patients with acute coronary syndrome and 73 age- and gender-matched control subjects. Rho-associated kinase activity within 2 hours of acute coronary syndrome onset was higher in patients with acute coronary syndrome than in the control subjects (0.95±0.55 versus 0.69±0.31; P<0.001). Rho-associated kinase activity promptly increased from 0.95±0.55 to 1.11±0.81 after 3 hours and reached a peak of 1.21±0.76 after 1 day (P=0.03 and P=0.03, respectively) and then gradually decreased to 0.83±0.52 after 7 days, 0.78±0.42 after 14 days, and 0.72±0.30 after 6 months (P=0.22, P=0.29, and P=0.12, respectively). During a median follow-up period of 50.8 months, 31 first major cardiovascular events (death from cardiovascular causes, myocardial infarction, ischemic stroke, and coronary revascularization) occurred. After adjustment for age, sex, cardiovascular risk factors, and concomitant treatment with statins, increased Rho-associated kinase activity was associated with increasing risk of first major cardiovascular events (hazard ratio, 4.56; 95% confidence interval, 1.98–11.34; P<0.001). These findings suggest that Rho-associated kinase activity is dramatically changed after acute coronary syndrome and that Rho-associated kinase activity could be a useful biomarker to predict cardiovascular events in Japanese patients with acute coronary syndrome. PMID:26283039

  14. Event counting alpha detector

    DOEpatents

    Bolton, Richard D.; MacArthur, Duncan W.

    1996-01-01

    An electrostatic detector for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure.

  15. Alpha-particle diagnostics

    SciTech Connect

    Young, K.M.

    1991-01-01

    This paper will focus on the state of development of diagnostics which are expected to provide the information needed for {alpha}- physics studies in the future. Conventional measurement of detailed temporal and spatial profiles of background plasma properties in DT will be essential for such aspects as determining heating effectiveness, shaping of the plasma profiles and effects of MHD, but will not be addressed here. This paper will address (1) the measurement of the neutron source, and hence {alpha}-particle birth profile, (2) measurement of the escaping {alpha}-particles and (3) measurement of the confined {alpha}-particles over their full energy range. There will also be a brief discussion of (4) the concerns about instabilities being generated by {alpha}-particles and the methods necessary for measuring these effects. 51 refs., 10 figs.

  16. Imaging alpha particle detector

    DOEpatents

    Anderson, D.F.

    1980-10-29

    A method and apparatus for detecting and imaging alpha particles sources is described. A dielectric coated high voltage electrode and a tungsten wire grid constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source to be quantitatively or qualitatively analyzed. A thin polyester film window allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  17. Imaging alpha particle detector

    DOEpatents

    Anderson, David F.

    1985-01-01

    A method and apparatus for detecting and imaging alpha particles sources is described. A conducting coated high voltage electrode (1) and a tungsten wire grid (2) constitute a diode configuration discharge generator for electrons dislodged from atoms or molecules located in between these electrodes when struck by alpha particles from a source (3) to be quantitatively or qualitatively analyzed. A thin polyester film window (4) allows the alpha particles to pass into the gas enclosure and the combination of the glass electrode, grid and window is light transparent such that the details of the source which is imaged with high resolution and sensitivity by the sparks produced can be observed visually as well. The source can be viewed directly, electronically counted or integrated over time using photographic methods. A significant increase in sensitivity over other alpha particle detectors is observed, and the device has very low sensitivity to gamma or beta emissions which might otherwise appear as noise on the alpha particle signal.

  18. Event counting alpha detector

    DOEpatents

    Bolton, R.D.; MacArthur, D.W.

    1996-08-27

    An electrostatic detector is disclosed for atmospheric radon or other weak sources of alpha radiation. In one embodiment, nested enclosures are insulated from one another, open at the top, and have a high voltage pin inside and insulated from the inside enclosure. An electric field is produced between the pin and the inside enclosure. Air ions produced by collision with alpha particles inside the decay volume defined by the inside enclosure are attracted to the pin and the inner enclosure. With low alpha concentrations, individual alpha events can be measured to indicate the presence of radon or other alpha radiation. In another embodiment, an electrical field is produced between parallel plates which are insulated from a single decay cavity enclosure. 6 figs.

  19. Rho Kinase Enhances Contractions of Rat Mesenteric Collecting Lymphatics

    PubMed Central

    Kurtz, Kristine H.; Souza-Smith, Flavia M.; Moor, Andrea N.; Breslin, Jerome W.

    2014-01-01

    The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca2+) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H2O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1–10 μM) and Y-27632 (0.5–50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca2+ ([Ca2+]i) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca2+-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1–10 μM H1152 or 25–50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca2+]i preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca2+]i between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca2+]i. Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose

  20. Rho kinase enhances contractions of rat mesenteric collecting lymphatics.

    PubMed

    Kurtz, Kristine H; Souza-Smith, Flavia M; Moor, Andrea N; Breslin, Jerome W

    2014-01-01

    The mechanisms that control phasic and tonic contractions of lymphatic vessels are poorly understood. We hypothesized that rho kinase ROCK, previously shown to increase calcium (Ca2+) sensitivity in vascular smooth muscle, enhances lymphatic contractile activity in a similar fashion. Contractions of isolated rat mesenteric lymphatic vessels were observed at a luminal pressure of 2 cm H2O in a 37°C bath. The expression of ROCK in isolated rat mesenteric lymphatic vessels was assessed by Western blotting and confocal microscopy. The role of ROCK in contractile function was tested using two specific yet structurally distinct inhibitors: H1152 (0.1-10 μM) and Y-27632 (0.5-50 μM). In addition, lymphatics were transfected with constitutively active (ca)-ROCK protein (2 μg/ml) to assess gain of contractile function. Vessel diameter and the concentration of intracellular free Ca2+ ([Ca2+]i) were simultaneously measured in a subset of isolated lymphatics loaded with the Ca2+-sensing dye fura-2. The results show expression of both the ROCK1 and ROCK2 isoforms in lymphatic vessels. Inhibition of ROCK increased lymphatic end diastolic diameter and end systolic diameter in a concentration-dependent manner. Significant reductions in lymphatic tone and contraction amplitude were observed after treatment 1-10 μM H1152 or 25-50 μM Y-27632. H1152 (10 μM) also significantly reduced contraction frequency. Transient increases in [Ca2+]i preceded each phasic contraction, however this pattern was disrupted by either 10 μM H1152 or 50 μM Y-27632 in the majority of lymphatics studied. The significant decrease in tone caused by H1152 or Y-27632 was not associated with a significant change in the basal [Ca2+]i between transients. Transfection with ca-ROCK protein enhanced lymphatic tone, but was not associated with a significant change in basal [Ca2+]i. Our data suggest that ROCK mediates normal tonic constriction and influences phasic contractions in lymphatics. We propose that

  1. CP asymmetries in B{yields}K{pi}, K*{pi}, {rho}K decays

    SciTech Connect

    Gronau, Michael; Pirjol, Dan; Zupan, Jure

    2010-05-01

    We show that ratios of tree and penguin amplitudes in B{yields}K*{pi} and B{yields}{rho}K are 2 to 3 times larger than in B{yields}K{pi}. This allows for considerably larger CP asymmetries in the former processes than the 10% asymmetry measured in B{sup 0{yields}}K{sup +{pi}-}. We study isospin sum rules for rate asymmetries in B{yields}K{pi}, K*{pi}, {rho}K, estimating small violation from interference of tree and electroweak penguin amplitudes. The breaking of the K{pi} asymmetry sum rule is estimated to be 1 to 2% and negative. Violation of K*{pi} and {rho}K sum rules can be estimated from B{yields}{rho}{pi} amplitudes using flavor SU(3), while breaking of a sum rule combining K*{pi} and {rho}K asymmetries can be measured directly in a Dalitz analysis of B{sup 0{yields}}K{sup +{pi}-{pi}0}. The three sum rules can be tested using complete sets of data taken at e{sup +}e{sup -} B factories and in experiments at the LHCb and at a future Super Flavor Factory, providing precision searches for new {Delta}S={Delta}I=1 operators in the low-energy effective Hamiltonian.

  2. Cancer Stem Cells and Radioresistance: Rho/ROCK Pathway Plea Attention.

    PubMed

    Pranatharthi, Annapurna; Ross, Cecil; Srivastava, Sweta

    2016-01-01

    Radiation is the most potent mode of cancer therapy; however, resistance to radiation therapy results in tumor relapse and subsequent fatality. The cancer stem cell (CSC), which has better DNA repair capability, has been shown to contribute to tumor resistance and is an important target for treatment. Signaling molecules such as Notch, Wnt, and DNA repair pathways regulate molecular mechanisms in CSCs; however, none of them have been translated into therapeutic targets. The RhoGTPases and their effector ROCK-signaling pathway, though important for tumor progression, have not been well studied in the context of radioresistance. There are reports that implicate RhoA in radioresistance. ROCK2 has also been shown to interact with BRCA2 in the regulation of cell division. Incidentally, statins (drug for cardiovascular ailment) are functional inhibitors of RhoGTPases. Studies suggest that patients on statins have a better prognosis in cancers. Data from our lab suggest that ROCK signaling regulates radioresistance in cervical cancer cells. Collectively, these findings suggest that Rho/ROCK signaling may be important for radiation resistance. In this review, we enumerate the role of Rho/ROCK signaling in stemness and radioresistance and highlight the need to explore these molecules for a better understanding of radioresistance and development of therapeutics. PMID:27597870

  3. Tyrosine glycosylation of Rho by Yersinia toxin impairs blastomere cell behaviour in zebrafish embryos

    PubMed Central

    Jank, Thomas; Eckerle, Stephanie; Steinemann, Marcus; Trillhaase, Christoph; Schimpl, Marianne; Wiese, Sebastian; van Aalten, Daan M. F.; Driever, Wolfgang; Aktories, Klaus

    2015-01-01

    Yersinia species cause zoonotic infections, including enterocolitis and plague. Here we studied Yersinia ruckeri antifeeding prophage 18 (Afp18), the toxin component of the phage tail-derived protein translocation system Afp, which causes enteric redmouth disease in salmonid fish species. Here we show that microinjection of the glycosyltransferase domain Afp18G into zebrafish embryos blocks cytokinesis, actin-dependent motility and cell blebbing, eventually abrogating gastrulation. In zebrafish ZF4 cells, Afp18G depolymerizes actin stress fibres by mono-O-GlcNAcylation of RhoA at tyrosine-34; thereby Afp18G inhibits RhoA activation by guanine nucleotide exchange factors, and blocks RhoA, but not Rac and Cdc42 downstream signalling. The crystal structure of tyrosine-GlcNAcylated RhoA reveals an open conformation of the effector loop distinct from recently described structures of GDP- or GTP-bound RhoA. Unravelling of the molecular mechanism of the toxin component Afp18 as glycosyltransferase opens new perspectives in studies of phage tail-derived protein translocation systems, which are preserved from archaea to human pathogenic prokaryotes. PMID:26190758

  4. Quantitative Assessment of Local Collagen Matrix Remodeling in 3-D Culture: The Role of Rho Kinase

    PubMed Central

    Kim, Areum; Lakshman, Neema; Petroll, W.Matthew

    2007-01-01

    The purpose of this study was to quantitatively assess the role of Rho kinase in modulating the pattern and amount of local cell-induced collagen matrix remodeling. Human corneal fibroblasts were plated inside 100 μm thick fibrillar collagen matrices and cultured for 24 hours in media with or without the Rho kinase inhibitor Y-27632. Cells were then fixed and stained with phalloidin. Fluorescent (for f-actin) and reflected light (for collagen fibrils) 3-D optical section images were acquired using laser confocal microscopy. Fourier transform analysis was used to assess collagen fibril alignment, and 3-D cell morphology and local collagen density were measured using MetaMorph. Culture in serum-containing media induced significant global matrix contraction, which was inhibited by blocking Rho kinase (p < 0.001). Fibroblasts generally had a bipolar morphology and intracellular stress fibers. Collagen fibrils were compacted and aligned parallel to stress fibers and pseudopodia. When Rho kinase was inhibited, cells had a more cortical f-actin distribution and dendritic morphology. Both local collagen fibril density and alignment were significantly reduced (p<0.01). Overall, the data suggests that Rho kinase dependent contractile force generation leads to co-alignment of cells and collagen fibrils along the plane of greatest resistance, and that this process contributes to global matrix contraction. PMID:16978606

  5. Ornithine decarboxylase regulates the activity and localization of rhoA via polyamination.

    PubMed

    Mäkitie, Laura T; Kanerva, Kristiina; Andersson, Leif C

    2009-04-01

    Ornithine decarboxylase (ODC) is the rate-limiting enzyme of polyamine synthesis. Polyamines and ODC are connected to cell proliferation and transformation. Resting cells display a low ODC activity while normal, proliferating cells display fluctuations in ODC activity that coincide with changes in the actin cytoskeleton during the cell cycle. Cancerous cells display constitutively elevated ODC activity. Overexpression of ODC in NIH 3T3 fibroblasts induces a transformed phenotype. The cytoskeletal rearrangements during cytokinesis and cell transformation are intimately coupled to the ODC activity but the molecular mechanisms have remained elusive. In this study we investigated how ODC and polyamines influence the organization of the cytoskeleton. Given that the small G-proteins of the rho family are key modulators of the actin cytoskeleton, we investigated the molecular interactions of rhoA with ODC and polyamines. Our results show that transglutaminase-catalyzed polyamination of rhoA regulates its activity. The polyamination status of rhoA crucially influences the progress of the cell cycle as well as the rate of transformation of rat fibroblasts infected with temperature-sensitive v-src. We also show that ODC influences the intracellular distribution of rhoA. These findings provide novel insights into the mechanisms by which ODC and polyamines regulate the dynamics of the cytoskeleton during cell proliferation and transformation. PMID:19331812

  6. Cancer Stem Cells and Radioresistance: Rho/ROCK Pathway Plea Attention

    PubMed Central

    Pranatharthi, Annapurna; Ross, Cecil

    2016-01-01

    Radiation is the most potent mode of cancer therapy; however, resistance to radiation therapy results in tumor relapse and subsequent fatality. The cancer stem cell (CSC), which has better DNA repair capability, has been shown to contribute to tumor resistance and is an important target for treatment. Signaling molecules such as Notch, Wnt, and DNA repair pathways regulate molecular mechanisms in CSCs; however, none of them have been translated into therapeutic targets. The RhoGTPases and their effector ROCK-signaling pathway, though important for tumor progression, have not been well studied in the context of radioresistance. There are reports that implicate RhoA in radioresistance. ROCK2 has also been shown to interact with BRCA2 in the regulation of cell division. Incidentally, statins (drug for cardiovascular ailment) are functional inhibitors of RhoGTPases. Studies suggest that patients on statins have a better prognosis in cancers. Data from our lab suggest that ROCK signaling regulates radioresistance in cervical cancer cells. Collectively, these findings suggest that Rho/ROCK signaling may be important for radiation resistance. In this review, we enumerate the role of Rho/ROCK signaling in stemness and radioresistance and highlight the need to explore these molecules for a better understanding of radioresistance and development of therapeutics. PMID:27597870

  7. Abr and Bcr are multifunctional regulators of the Rho GTP-binding protein family.

    PubMed Central

    Chuang, T H; Xu, X; Kaartinen, V; Heisterkamp, N; Groffen, J; Bokoch, G M

    1995-01-01

    Philadelphia chromosome-positive leukemias result from the fusion of the BCR and ABL genes, which generates a functional chimeric molecule. The Abr protein is very similar to Bcr but lacks a structural domain which may influence its biological regulatory capabilities. Both Abr and Bcr have a GTPase-activating protein (GAP) domain similar to those found in other proteins that stimulate GTP hydrolysis by members of the Rho family of GTP-binding proteins, as well as a region of homology with the guanine nucleotide dissociation-stimulating domain of the DBL oncogene product. We purified as recombinant fusion proteins the GAP- and Dbl-homology domains of both Abr and Bcr. The Dbl-homology domains of Bcr and Abr were active in stimulating GTP binding to CDC42Hs, RhoA, Rac1, and Rac2 (rank order, CDC42Hs > RhoA > Rac1 = Rac2) but were inactive toward Rap1A and Ha-Ras. Both Bcr and Abr acted as GAPs for Rac1, Rac2, and CDC42Hs but were inactive toward RhoA, Rap1A, and Ha-Ras. Each individual domain bound in a noncompetitive manner to GTP-binding protein substrates. These data suggest the multifunctional Bcr and Abr proteins might interact simultaneously and/or sequentially with members of the Rho family to regulate and coordinate cellular signaling. Images Fig. 3 PMID:7479768

  8. Control of Homeostasis and Dendritic Cell Survival by the GTPase RhoA.

    PubMed

    Li, Shuai; Dislich, Bastian; Brakebusch, Cord H; Lichtenthaler, Stefan F; Brocker, Thomas

    2015-11-01

    Tissues accommodate defined numbers of dendritic cells (DCs) in highly specific niches where different intrinsic and environmental stimuli control DC life span and numbers. DC homeostasis in tissues is important, because experimental changes in DC numbers influence immunity and tolerance toward various immune catastrophes and inflammation. However, the precise molecular mechanisms regulating DC life span and homeostasis are unclear. We report that the GTPase RhoA controls homeostatic proliferation, cytokinesis, survival, and turnover of cDCs. Deletion of RhoA strongly decreased the numbers of CD11b(-)CD8(+) and CD11b(+)Esam(hi) DC subsets, whereas CD11b(+)Esam(lo) DCs were not affected in conditional RhoA-deficient mice. Proteome analyses revealed a defective prosurvival pathway via PI3K/protein kinase B (Akt1)/Bcl-2-associated death promoter in the absence of RhoA. Taken together, our findings identify RhoA as a central regulator of DC homeostasis, and its deletion decreases DC numbers below critical thresholds for immune protection and homeostasis, causing aberrant compensatory DC proliferation. PMID:26408665

  9. Tyrosine glycosylation of Rho by Yersinia toxin impairs blastomere cell behaviour in zebrafish embryos.

    PubMed

    Jank, Thomas; Eckerle, Stephanie; Steinemann, Marcus; Trillhaase, Christoph; Schimpl, Marianne; Wiese, Sebastian; van Aalten, Daan M F; Driever, Wolfgang; Aktories, Klaus

    2015-01-01

    Yersinia species cause zoonotic infections, including enterocolitis and plague. Here we studied Yersinia ruckeri antifeeding prophage 18 (Afp18), the toxin component of the phage tail-derived protein translocation system Afp, which causes enteric redmouth disease in salmonid fish species. Here we show that microinjection of the glycosyltransferase domain Afp18(G) into zebrafish embryos blocks cytokinesis, actin-dependent motility and cell blebbing, eventually abrogating gastrulation. In zebrafish ZF4 cells, Afp18(G) depolymerizes actin stress fibres by mono-O-GlcNAcylation of RhoA at tyrosine-34; thereby Afp18(G) inhibits RhoA activation by guanine nucleotide exchange factors, and blocks RhoA, but not Rac and Cdc42 downstream signalling. The crystal structure of tyrosine-GlcNAcylated RhoA reveals an open conformation of the effector loop distinct from recently described structures of GDP- or GTP-bound RhoA. Unravelling of the molecular mechanism of the toxin component Afp18 as glycosyltransferase opens new perspectives in studies of phage tail-derived protein translocation systems, which are preserved from archaea to human pathogenic prokaryotes. PMID:26190758

  10. Molecular characterization of the human red cell Rho(D) antigen.

    PubMed Central

    Gahmberg, C G

    1983-01-01

    Human red cells of Rh blood groups -D-/-D- ('super-D'), -/- (Rhnull) and normal Rho(D)+ cells were radioactively surface-labeled using the lactoperoxidase 125I method. Polyacrylamide gel electrophoresis in the presence of SDS followed by fluorography showed a strong enrichment of a polypeptide with an apparent mol. wt. of 28,0000-33,000 in the 125I-labeled -D-/-D- membranes. This polypeptide was specifically immune precipitated with anti-Rho(D) antiserum. Treatment of intact cells with trypsin or Pronase did not digest the protein. The Rho polypeptide migrated identically on polyacrylamide gel electrophoresis under reducing and non-reducing conditions. It was not phosphorylated after in vitro incubation of red cells with 32P. When whole labeled membranes were solubilized in neutral detergent and applied to lectin-Sepharose columns the Rho(D) polypeptide adsorbed to Ricinus communis lectin but not to wheat germ lectin or Lens culinaris lectin. The purified molecule did not adsorb to R. communis lectin-Sepharose. Treatment of the Rho(D) antigen with endo-N-acetyl glucosaminidase H, endo-beta-galactosidase or mild alkali did not lower its apparent mol. wt. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. PMID:11894930

  11. Microtubules Regulate Migratory Polarity through Rho/ROCK Signaling in T Cells

    PubMed Central

    Takesono, Aya; Heasman, Sarah J.; Wojciak-Stothard, Beata; Garg, Ritu; Ridley, Anne J.

    2010-01-01

    Background Migrating leukocytes normally have a polarized morphology with an actin-rich lamellipodium at the front and a uropod at the rear. Microtubules (MTs) are required for persistent migration and chemotaxis, but how they affect cell polarity is not known. Methodology/Principal Findings Here we report that T cells treated with nocodazole to disrupt MTs are unable to form a stable uropod or lamellipodium, and instead often move by membrane blebbing with reduced migratory persistence. However, uropod-localized receptors and ezrin/radixin/moesin proteins still cluster in nocodazole-treated cells, indicating that MTs are required specifically for uropod stability. Nocodazole stimulates RhoA activity, and inhibition of the RhoA target ROCK allows nocodazole-treated cells to re-establish lamellipodia and uropods and persistent migratory polarity. ROCK inhibition decreases nocodazole-induced membrane blebbing and stabilizes MTs. The myosin inhibitor blebbistatin also stabilizes MTs, indicating that RhoA/ROCK act through myosin II to destabilize MTs. Conclusions/Significance Our results indicate that RhoA/ROCK signaling normally contributes to migration by affecting both actomyosin contractility and MT stability. We propose that regulation of MT stability and RhoA/ROCK activity is a mechanism to alter T-cell migratory behavior from lamellipodium-based persistent migration to bleb-based migration with frequent turning. PMID:20098744

  12. Measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)h(-/+) decays.

    PubMed

    Aubert, B; Barate, R; Boutigny, D; Gaillard, J-M; Hicheur, A; Karyotakis, Y; Lees, J P; Robbe, P; Tisserand, V; Zghiche, A; Palano, A; Pompili, A; Chen, J C; Qi, N D; Rong, G; Wang, P; Zhu, Y S; Eigen, G; Ofte, I; Stugu, B; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R N; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Yu G; Kral, J F; Kukartsev, G; LeClerc, C; Levi, M E; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Romosan, A; Ronan, M T; Shelkov, V G; Telnov, A V; Wenzel, W A; Ford, K; Harrison, T J; Hawkes, C M; Knowles, D J; Morgan, S E; Penny, R C; Watson, A T; Watson, N K; Deppermann, T; Goetzen, K; Koch, H; Lewandowski, B; Pelizaeus, M; Peters, K; Schmuecker, H; Steinke, M; Barlow, N R; Boyd, J T; Chevalier, N; Cottingham, W N; Kelly, M P; Latham, T E; Mackay, C; Wilson, F F; Abe, K; Cuhadar-Donszelmann, T; Hearty, C; Mattison, T S; McKenna, J A; Thiessen, D; Kyberd, P; McKemey, A K; Blinov, V E; Bukin, A D; Golubev, V B; Ivanchenko, V N; Kravchenko, E A; Onuchin, A P; Serednyakov, S I; Skovpen, Yu I; Solodov, E P; Yushkov, A N; Best, D; Chao, M; Kirkby, D; Lankford, A J; Mandelkern, M; McMahon, S; Mommsen, R K; Roethel, W; Stoker, D P; Buchanan, C; del Re, D; Hadavand, H K; Hill, E J; MacFarlane, D B; Paar, H P; Rahatlou, Sh; Schwanke, U; Sharma, V; Berryhill, J W; Campagnari, C; Dahmes, B; Kuznetsova, N; Levy, S L; Long, O; Lu, A; Mazur, M A; Richman, J D; Verkerke, W; Beck, T W; Beringer, J; Eisner, A M; Heusch, C A; Lockman, W S; Schalk, T; Schmitz, R E; Schumm, B A; Seiden, A; Turri, M; Walkowiak, W; Williams, D C; Wilson, M G; Albert, J; Chen, E; Dubois-Felsmann, G P; Dvoretskii, A; Hitlin, D G; Narsky, I; Porter, F C; Ryd, A; Samuel, A; Yang, S; Jayatilleke, S; Mancinelli, G; Meadows, B T; Sokoloff, M D; Abe, T; Barillari, T; Blanc, F; Bloom, P; Clark, P J; Ford, W T; Nauenberg, U; Olivas, A; Rankin, P; Roy, J; Smith, J G; van Hoek, W C; Zhang, L; Harton, J L; Hu, T; Soffer, A; Toki, W H; Wilson, R J; Zhang, J; Altenburg, D; Brandt, T; Brose, J; Colberg, T; Dickopp, M; Dubitzky, R S; Hauke, A; Lacker, H M; Maly, E; Müller-Pfefferkorn, R; Nogowski, R; Otto, S; Schubert, K R; Schwierz, R; Spaan, B; Wilden, L; Bernard, D; Bonneaud, G R; Brochard, F; Cohen-Tanugi, J; Thiebaux, Ch; Vasileiadis, G; Verderi, M; Khan, A; Lavin, D; Muheim, F; Playfer, S; Swain, J E; Tinslay, J; Andreotti, M; Bettoni, D; Bozzi, C; Calabrese, R; Cibinetto, G; Luppi, E; Negrini, M; Piemontese, L; Sarti, A; Treadwell, E; Anulli, F; Baldini-Ferroli, R; Calcaterra, A; de Sangro, R; Falciai, D; Finocchiaro, G; Patteri, P; Peruzzi, I M; Piccolo, M; Zallo, A; Buzzo, A; Contri, R; Crosetti, G; Lo Vetere, M; Macri, M; Monge, M R; Passaggio, S; Pastore, F C; Patrignani, C; Robutti, E; Santroni, A; Tosi, S; Bailey, S; Morii, M; Aspinwall, M L; Bhimji, W; Bowerman, D A; Dauncey, P D; Egede, U; Eschrich, I; Morton, G W; Nash, J A; Sanders, P; Taylor, G P; Grenier, G J; Lee, S-J; Mallik, U; Cochran, J; Crawley, H B; Lamsa, J; Meyer, W T; Prell, S; Rosenberg, E I; Yi, J; Davier, M; Grosdidier, G; Höcker, A; Laplace, S; Le Diberder, F; Lepeltier, V; Lutz, A M; Petersen, T C; Plaszczynski, S; Schune, M H; Tantot, L; Wormser, G; Brigljević, V; Cheng, C H; Lange, D J; Wright, D M; Bevan, A J; Coleman, J P; Fry, J R; Gabathuler, E; Gamet, R; Kay, M; Parry, R J; Payne, D J; Sloane, R J; Touramanis, C; Back, J J; Harrison, P F; Shorthouse, H W; Strother, P; Vidal, P B; Brown, C L; Cowan, G; Flack, R L; Flaecher, H U; George, S; Green, M G; Kurup, A; Marker, C E; McMahon, T R; Ricciardi, S; Salvatore, F; Vaitsas, G; Winter, M A; Brown, D; Davis, C L; Allison, J; Barlow, R J; Forti, A C; Hart, P A; Jackson, F; Lafferty, G D; Lyon, A J; Weatherall, J H; Williams, J C; Farbin, A; Jawahery, A; Kovalskyi, D; Lae, C K; Lillard, V; Roberts, D A; Blaylock, G; Dallapiccola, C; Flood, K T; Hertzbach, S S; Kofler, R; Koptchev, V B; Moore, T B; Saremi, S; Staengle, H; Willocq, S; Cowan, R; Sciolla, G; Taylor, F; Yamamoto, R K; Mangeol, D J J; Milek, M; Patel, P M; Lazzaro, A; Palombo, F; Bauer, J M; Cremaldi, L; Eschenburg, V; Godang, R; Kroeger, R; Reidy, J; Sanders, D A; Summers, D J; Zhao, H W; Hast, C; Taras, P; Nicholson, H; Cartaro, C; Cavallo, N; De Nardo, G; Fabozzi, F; Gatto, C; Lista, L; Paolucci, P; Piccolo, D; Sciacca, C; Baak, M A; Raven, G; LoSecco, J M; Gabriel, T A; Brau, B; Pulliam, T; Brau, J; Frey, R; Potter, C T; Sinev, N B; Strom, D; Torrence, E; Colecchia, F; Dorigo, A; Galeazzi, F; Margoni, M; Morandin, M; Posocco, M; Rotondo, M; Simonetto, F; Stroili, R; Tiozzo, G; Voci, C; Benayoun, M; Briand, H; Chauveau, J; David, P; de la Vaissière, Ch; Del Buono, L; Hamon, O; John, M J J; Leruste, Ph; Ocariz, J; Pivk, M; Roos, L; Stark, J; T'Jampens, S; Manfredi, P F; Re, V; Gladney, L; Guo, Q H; Panetta, J; Angelini, C; Batignani, G; Bettarini, S; Bondioli, M; Bucci, F; Calderini, G; Carpinelli, M; Forti, F; Giorgi, M A; Lusiani, A; Marchiori, G; Martinez-Vidal, F; Morganti, M; Neri, N; Paoloni, E; Rama, M; Rizzo, G; Sandrelli, F; Walsh, J; Haire, M; Judd, D; Paick, K; Wagoner, D E; Danielson, N; Elmer, P; Lu, C; Miftakov, V; Olsen, J; Smith, A J S; Varnes, E W; Bellini, F; Cavoto, G; Faccini, R; Ferrarotto, F; Ferroni, F; Gaspero, M; Mazzoni, M A; Morganti, S; Pierini, M; Piredda, G; Safai Tehrani, F; Voena, C; Christ, S; Wagner, G; Waldi, R; Adye, T; De Groot, N; Franek, B; Geddes, N I; Gopal, G P; Olaiya, E O; Xella, S M; Aleksan, R; Emery, S; Gaidot, A; Ganzhur, S F; Giraud, P-F; Hamel de Monchenault, G; Kozanecki, W; Langer, M; London, G W; Mayer, B; Schott, G; Vasseur, G; Yeche, Ch; Zito, M; Purohit, M V; Weidemann, A W; Yumiceva, F X; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Convery, M R; Coupal, D P; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Field, R C; Glanzman, T; Gowdy, S J; Grauges-Pous, E; Hadig, T; Halyo, V; Hryn'ova, T; Innes, W R; Jessop, C P; Kelsey, M H; Kim, P; Kocian, M L; Langenegger, U; Leith, D W G S; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Menke, S; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Robertson, S H; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Simi, G; Snyder, A; Soha, A; Stelzer, J; Su, D; Sullivan, M K; Tanaka, H A; Va'vra, J; Wagner, S R; Weaver, M; Weinstein, A J R; Wisniewski, W J; Wright, D H; Young, C C; Burchat, P R; Edwards, A J; Meyer, T I; Roat, C; Ahmed, S; Alam, M S; Ernst, J A; Saleem, M; Wappler, F R; Bugg, W; Krishnamurthy, M; Spanier, S M; Eckmann, R; Kim, H; Ritchie, J L; Schwitters, R F; Izen, J M; Kitayama, I; Lou, X C; Ye, S; Bianchi, F; Bona, M; Gallo, F; Gamba, D; Borean, C; Bosisio, L; Della Ricca, G; Dittongo, S; Grancagnolo, S; Lanceri, L; Poropat, P; Vitale, L; Vuagnin, G; Panvini, R S; Banerjee, Sw; Brown, C M; Fortin, D; Jackson, P D; Kowalewski, R; Roney, J M; Band, H R; Dasu, S; Datta, M; Eichenbaum, A M; Hu, H; Johnson, J R; Kutter, P E; Li, H; Liu, R; Di Lodovico, F; Mihalyi, A; Mohapatra, A K; Pan, Y; Prepost, R; Sekula, S J; von Wimmersperg-Toeller, J H; Wu, J; Wu, S L; Yu, Z; Neal, H

    2003-11-14

    We present measurements of branching fractions and CP-violating asymmetries in B0-->rho(+/-)pi(-/+) and B0-->rho-K+ decays. The results are obtained from a data sample of 88.9 x 10(6) Upsilon(4S)-->BB decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy B Factory. From a time-dependent maximum likelihood fit we measure the branching fractions B(B0-->rho(+/-)pi(-/+))=[22.6+/-1.8 (stat)+/-2.2 (syst)]x10(-6) and B(B0-->rho-K+)=(7.3 -1.2( +1.3)+/-1.3)x10(-6), and the CP-violating charge asymmetries A(rhopi)(CP)=-0.18+/-0.08+/-0.03 and A(rhoK)(CP)=0.28+/-0.17+/-0.08, the direct CP violation parameter C(rhopi)=0.36+/-0.18+/-0.04 and the mixing-induced CP violation parameter S(rhopi)=0.19+/-0.24+/-0.03, and the dilution parameters DeltaC(rhopi)=0.28 -0.19( +0.18)+/-0.04 and DeltaS(rhopi)=0.15+/-0.25+/-0.03. PMID:14683353

  13. Rho-associated kinase signalling and the cancer microenvironment: novel biological implications and therapeutic opportunities.

    PubMed

    Chin, Venessa T; Nagrial, Adnan M; Chou, Angela; Biankin, Andrew V; Gill, Anthony J; Timpson, Paul; Pajic, Marina

    2015-01-01

    The Rho/ROCK pathway is involved in numerous pivotal cellular processes that have made it an area of intense study in cancer medicine, however, Rho-associated coiled-coil containing protein kinase (ROCK) inhibitors are yet to make an appearance in the clinical cancer setting. Their performance as an anti-cancer therapy has been varied in pre-clinical studies, however, they have been shown to be effective vasodilators in the treatment of hypertension and post-ischaemic stroke vasospasm. This review addresses the various roles the Rho/ROCK pathway plays in angiogenesis, tumour vascular tone and reciprocal feedback from the tumour microenvironment and explores the potential utility of ROCK inhibitors as effective vascular normalising agents. ROCK inhibitors may potentially enhance the delivery and efficacy of chemotherapy agents and improve the effectiveness of radiotherapy. As such, repurposing of these agents as adjuncts to standard treatments may significantly improve outcomes for patients with cancer. A deeper understanding of the controlled and dynamic regulation of the key components of the Rho pathway may lead to effective use of the Rho/ROCK inhibitors in the clinical management of cancer. PMID:26507949

  14. Bacterial factors exploit eukaryotic Rho GTPase signaling cascades to promote invasion and proliferation within their host

    PubMed Central

    Popoff, Michel R

    2014-01-01

    Actin cytoskeleton is a main target of many bacterial pathogens. Among the multiple regulation steps of the actin cytoskeleton, bacterial factors interact preferentially with RhoGTPases. Pathogens secrete either toxins which diffuse in the surrounding environment, or directly inject virulence factors into target cells. Bacterial toxins, which interfere with RhoGTPases, and to some extent with RasGTPases, catalyze a covalent modification (ADPribosylation, glucosylation, deamidation, adenylation, proteolysis) blocking these molecules in their active or inactive state, resulting in alteration of epithelial and/or endothelial barriers, which contributes to dissemination of bacteria in the host. Injected bacterial virulence factors preferentially manipulate the RhoGTPase signaling cascade by mimicry of eukaryotic regulatory proteins leading to local actin cytoskeleton rearrangement, which mediates bacterial entry into host cells or in contrast escape to phagocytosis and immune defense. Invasive bacteria can also manipulate RhoGTPase signaling through recognition and stimulation of cell surface receptor(s). Changes in RhoGTPase activation state is sensed by the innate immunity pathways and allows the host cell to adapt an appropriate defense response. PMID:25203748

  15. The alpha channeling effect

    SciTech Connect

    Fisch, N. J.

    2015-12-10

    Alpha particles born through fusion reactions in a tokamak reactor tend to slow down on electrons, but that could take up to hundreds of milliseconds. Before that happens, the energy in these alpha particles can destabilize on collisionless timescales toroidal Alfven modes and other waves, in a way deleterious to energy confinement. However, it has been speculated that this energy might be instead be channeled into useful energy, so as to heat fuel ions or to drive current. Such a channeling needs to be catalyzed by waves Waves can produce diffusion in energy of the alpha particles in a way that is strictly coupled to diffusion in space. If these diffusion paths in energy-position space point from high energy in the center to low energy on the periphery, then alpha particles will be cooled while forced to the periphery. The energy from the alpha particles is absorbed by the wave. The amplified wave can then heat ions or drive current. This process or paradigm for extracting alpha particle energy collisionlessly has been called alpha channeling. While the effect is speculative, the upside potential for economical fusion is immense. The paradigm also operates more generally in other contexts of magnetically confined plasma.

  16. RhoGTPases as Key Players in Mammalian Cell Adaptation to Microgravity

    PubMed Central

    Deroanne, Christophe; Nusgens, Betty; Vico, Laurence; Guignandon, Alain

    2015-01-01

    A growing number of studies are revealing that cells reorganize their cytoskeleton when exposed to conditions of microgravity. Most, if not all, of the structural changes observed on flown cells can be explained by modulation of RhoGTPases, which are mechanosensitive switches responsible for cytoskeletal dynamics control. This review identifies general principles defining cell sensitivity to gravitational stresses. We discuss what is known about changes in cell shape, nucleus, and focal adhesions and try to establish the relationship with specific RhoGTPase activities. We conclude by considering the potential relevance of live imaging of RhoGTPase activity or cytoskeletal structures in order to enhance our understanding of cell adaptation to microgravity-related conditions. PMID:25649831

  17. Possible additional roles in mating for Ustilago maydis Rho1 and 14-3-3 homologues

    PubMed Central

    Pham, Cau D

    2010-01-01

    Both the Rho GTPases and 14-3-3 proteins each belong to ubiquitous families of proteins involved in a variety of cellular processes, including cytokinesis, cell polarity, cellular differentiation and apoptosis. In fungi, these components of signaling pathways are involved in cell cycle regulation, cytokinesis and virulence. We study cellular differentiation and pathogenesis for Ustilago maydis, the dimorphic fungal pathogen of maize. We have reported on the interactions of Pdc1, a U. maydis homologue of human 14-3-3ɛ, with Rho1, a small GTP binding protein; these proteins participate in cell polarity and filamentation pathways that include another small G protein, Rac1, and its effector PAK kinase, Cla4. Here we describe additional experiments that explore possible relationships of Pdc1 and Rho1 with another PAK-like kinase pathway and with the a matingtype locus. PMID:20539785

  18. Foci of cyclin A2 interact with actin and RhoA in mitosis

    PubMed Central

    Loukil, Abdelhalim; Izard, Fanny; Georgieva, Mariya; Mashayekhan, Shaereh; Blanchard, Jean-Marie; Parmeggiani, Andrea; Peter, Marion

    2016-01-01

    Cyclin A2 is a key player in the regulation of the cell cycle. Its degradation in mid-mitosis depends primarily on the ubiquitin-proteasome system (UPS), while autophagy also contributes. However, a fraction of cyclin A2 persists beyond metaphase. In this work, we focus on cyclin A2-rich foci detected in mitosis by high resolution imaging and analyse their movements. We demonstrate that cyclin A2 interacts with actin and RhoA during mitosis, and that cyclin A2 depletion induces a dramatic decrease in active RhoA in mitosis. Our data suggest cyclin A2 participation in RhoA activation in late mitosis. PMID:27279564

  19. Nonperturbative finite T broadening of the {rho} meson and dilepton emission in heavy-ion collisions

    SciTech Connect

    Ruppert, Joerg; Renk, Thorsten

    2005-06-01

    We study self-consistently the finite T broadening of the {rho} meson and its implications for dilepton emission in heavy-ion collisions. For this purpose finite width effects at finite temperature due to the {rho}-{pi} interaction are investigated in a self-consistent {phi}-functional approach. The temperature dependence of the {rho} meson and pion spectral functions and self-energies is discussed. The spectral functions show considerable broadening in comparison with a perturbative calculation on the one-loop level. Using these spectral functions, we make a comparison to dilepton emission data from the CERES NA49 Collaboration employing a parametrized fireball evolution model of collision. We demonstrate that these nonperturbative finite width effects are in-medium modifications relevant to the understanding of the enhancement of the low invariant mass spectrum of dileptons emitted in A-A collisions.

  20. Structural basis for induced-fit binding of Rho-kinase to the inhibitor Y-27632.

    PubMed

    Yamaguchi, Hiroto; Miwa, Yukiko; Kasa, Miyuki; Kitano, Ken; Amano, Mutsuki; Kaibuchi, Kozo; Hakoshima, Toshio

    2006-09-01

    Rho-kinase is a main player in the regulation of cytoskeletal events and a promising drug target in the treatment of both vascular and neurological disorders. Here we report the crystal structure of the Rho-kinase catalytic domain in complex with the specific inhibitor Y-27632. Comparison with the structure of PKA bound to this inhibitor revealed a potential induced-fit binding mode that can be accommodated by the phosphate binding loop. This binding mode resembles to that observed in the Rho-kinase-fasudil complex. A structural database search indicated that a pocket underneath the phosphate-binding loop is present that favors binding to a small aromatic ring. Introduction of such a ring group might spawn a new modification scheme of pre-existing protein kinase inhibitors for improved binding capability. PMID:16891330

  1. The Regulation of Cellular Responses to Mechanical Cues by Rho GTPases

    PubMed Central

    Hoon, Jing Ling; Tan, Mei Hua; Koh, Cheng-Gee

    2016-01-01

    The Rho GTPases regulate many cellular signaling cascades that modulate cell motility, migration, morphology and cell division. A large body of work has now delineated the biochemical cues and pathways, which stimulate the GTPases and their downstream effectors. However, cells also respond exquisitely to biophysical and mechanical cues such as stiffness and topography of the extracellular matrix that profoundly influence cell migration, proliferation and differentiation. As these cellular responses are mediated by the actin cytoskeleton, an involvement of Rho GTPases in the transduction of such cues is not unexpected. In this review, we discuss an emerging role of Rho GTPase proteins in the regulation of the responses elicited by biophysical and mechanical stimuli. PMID:27058559

  2. High Throughput Flow Cytometry Bead-based Multiplex Assay for Identification of Rho GTPase Inhibitors

    PubMed Central

    Surviladze, Zurab; Young, Susan M; Sklar, Larry A

    2015-01-01

    Summary Rho family GTPases and their effector proteins regulate a wide range of cell signaling pathways. In normal physiological conditions their activity is tightly controlled and it is not surprising that their aberrant activation contributes to tumorigenesis or other diseases. For this reason, the identification of small, cell permeable molecules capable of inhibition of Rho GTPases can be extraordinarily useful, particularly if they are specific and act reversibly. Herein we describe a flow cytometric assay, which allows us to measure the activity of six small GTPases simultaneously. GST-tagged small GTPases are bound to six glutathione bead sets each set having a different intensity of red fluorescence at a fixed wavelength. The coated bead sets were washed, combined, and dispensed into 384-well plates with test compounds, and fluorescent-GTP binding was used as the read-out. This multiplex bead-based assay was successfully used for to identify both general and selective inhibitors of Rho family GTPases. PMID:22144280

  3. Photoproduction of the rho(0) meson on the proton at large momentum transfer.

    PubMed

    Battaglieri, M; Anciant, E; Anghinolfi, M; De Vita, R; Golovach, E; Laget, J M; Mokeev, V; Ripani, M; Adams, G; Amaryan, M J; Armstrong, D S; Asavapibhop, B; Asryan, G; Audit, G; Auger, T; Avakian, H; Barrow, S; Beard, K; Bektasoglu, M; Berman, B L; Bianchi, N; Biselli, A S; Boiarinov, S; Branford, D; Briscoe, W J; Brooks, W K; Burkert, V D; Calarco, J R; Capitani, G P; Carman, D S; Carnahan, B; Cazes, A; Cetina, C; Cole, P L; Coleman, A; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J P; DeSanctis, E; Degtyarenko, P V; Demirchyan, R; Denizli, H; Dennis, L; Dharmawardane, K V; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Eckhause, M; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Farhi, L; Feuerbach, R J; Ficenec, J; Forest, T A; Freyberger, A P; Frolov, V; Funsten, H; Gaff, S J; Gai, M; Gilad, S; Gilfoyle, G P; Giovanetti, K L; Griffioen, K; Guidal, M; Guillo, M; Gyurjyan, V; Hancock, D; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Hicks, R S; Holtrop, M; Hyde-Wright, C E; Ito, M M; Joo, K; Kelley, J H; Khandaker, M; Kim, W; Klein, A; Klein, F J; Klusman, M; Kossov, M; Kramer, L H; Kuang, Y; Kuhn, S E; Lawrence, D; Lucas, M; Lukashin, K; Major, R W; Manak, J J; Marchand, C; McAleer, S; McCarthy, J; McNabb, J W; Mecking, B A; Mestayer, M D; Meyer, C A; Mikhailov, K; Minehart, R; Mirazita, M; Miskimen, R; Muccifora, V; Mueller, J; Mutchler, G S; Napolitano, J; Nelson, S O; Niczyporuk, B B; Niyazov, R A; O'Brien, J T; Opper, A K; Peterson, G; Philips, S A; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Preedom, B M; Price, J W; Protopopescu, D; Qin, L M; Raue, B A; Reolon, A R; Riccardi, G; Ricco, G; Ritchie, B G; Ronchetti, F; Rossi, P; Rowntree, D; Rubin, P D; Sabourov, K; Salgado, C; Sanzone-Arenhovel, M; Sapunenko, V; Schumacher, R A; Serov, V S; Shafi, A; Sharabian, Y G; Shaw, J; Skabelin, A V; Smith, E S; Smith, T; Smith, L C; Sober, D I; Spraker, M; Stavinsky, A; Stepanyan, S; Stoler, P; Taiuti, M; Taylor, S; Tedeschi, D J; Todor, L; Thompson, R; Vineyard, M F; Vlassov, A V; Weinstein, L B; Weisberg, A; Weller, H; Weygand, D P; Whisnant, C S; Wolin, E; Wood, M; Yegneswaran, A; Yun, J; Zhang, B; Zhao, J; Zhou, Z

    2001-10-22

    The differential cross section, d sigma/dt, for rho(0) meson photoproduction on the proton above the resonance region was measured up to a momentum transfer -t = 5 GeV2 using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The rho(0) channel was extracted from the measured two charged-pion cross sections by fitting the pi(+)pi(-) and p pi(+) invariant masses. The low momentum transfer region shows the typical diffractive pattern expected from Reggeon exchange. The flatter behavior at large -t cannot be explained solely in terms of QCD-inspired two-gluon exchange models. The data indicate that other processes, like quark interchange, are important to fully describe rho photoproduction. PMID:11690264

  4. Induction of transient macroapertures in endothelial cells through RhoA inhibition by Staphylococcus aureus factors.

    PubMed

    Boyer, Laurent; Doye, Anne; Rolando, Monica; Flatau, Gilles; Munro, Patrick; Gounon, Pierre; Clément, René; Pulcini, Céline; Popoff, Michel R; Mettouchi, Amel; Landraud, Luce; Dussurget, Olivier; Lemichez, Emmanuel

    2006-06-01

    The GTPase RhoA is a major regulator of the assembly of actin stress fibers and the contractility of the actomyosin cytoskeleton. The epidermal cell differentiation inhibitor (EDIN) and EDIN-like ADP-ribosyltransferases of Staphylococcus aureus catalyze the inactivation of RhoA, producing actin cable disruption. We report that purified recombinant EDIN and EDIN-producing S. aureus provoke large transcellular tunnels in endothelial cells that we have named macroapertures (MAs). These structures open transiently, followed by the appearance of actin-containing membrane waves extending over the aperture. Disruption of actin cables, either directly or indirectly, through rhoA RNAi knockdown also triggers the formation of MAs. Intoxication of endothelial monolayers by EDIN produces a loss of barrier function and provides direct access of the endothelium basement membrane to S. aureus. PMID:16754962

  5. Structure and decay constant of the {rho} meson within the Bethe-Salpeter equation

    SciTech Connect

    Wang, Z. G.; Wan, S. L.

    2007-08-15

    In this article, we study the structure of the {rho} meson in the framework of the coupled rainbow Schwinger-Dyson equation and ladder Bethe-Salpeter equation with a confining effective potential. The u and d quark propagators get significantly modified, the mass poles are absent in the timelike region, which implements confinement naturally. The Bethe-Salpeter amplitudes of the {rho} meson center around zero momentum and extend to the energy scale about q{sup 2}=1 GeV{sup 2}, which happens to be the energy scale of chiral symmetry breaking, strong interactions in the infrared region result in bound state. The numerical results of the mass and decay constant of the {rho} meson are in agreement with the experimental data.

  6. High RhoA expression at the tumor front in clinically localized prostate cancer and association with poor tumor differentiation

    PubMed Central

    CHEN, WEIHUA; DELONGCHAMPS, NICOLAS BARRY; MAO, KAILI; BEUVON, FRÉDÉRIC; PEYROMAURE, MICHAËL; LIU, ZHONGMIN; DINH-XUAN, ANH TUAN

    2016-01-01

    Ras homolog gene family, member A (RhoA) has been reported as essential to the invasion process and aggressiveness of numerous cancers. However, there are only sparse data on the expression and activity of RhoA in clinically localised prostate cancer. In numerous cancers, tumour cells at the invasive front demonstrate more aggressive behaviour in comparison with the cells in the central regions. In the present study, the expression and activity of RhoA was evaluated in 34 paraffin-embedded and 20 frozen prostate tissue specimens obtained from 45 patients treated with radical prostatectomy for clinically localised cancer. The expression patterns of RhoA were assessed by immunohistochemical staining and western blotting. Additional comparisons were performed between the tumour centre, tumour front and distant peritumoural tissue. RhoA activity was assessed by G-LISA. Associations between RhoA expression and the clinical features and outcome of the patients were also analysed. The present study found an increasing gradient of expression from the centre to the periphery of index tumour foci. RhoA expression was significantly increased at the tumour front compared to the tumour centre, which was determined using immunohistochemistry (P=0.001). Increased RhoA expression was associated with poor tumour differentiation in the tumour front (P=0.044) and tumour centre (P=0.039). Subsequent to a median follow-up period of 52 months, the rate of prostate-specific antigen (PSA) relapse was increased in patients with higher RhoA expression at the tumour front when compared with patients with lower RhoA expression (62.5 vs. 35.0%), although the difference was not significant (P=0.09). There was no association between RhoA expression and the PSA level or pathological stage in the present study. In conclusion, RhoA expression was increased at the tumour front and was associated with poor tumour differentiation in the tumour front and tumour centre, indicating the potential role of

  7. Antipsychotic drugs induce cell cytoskeleton reorganization in glial and neuronal cells via Rho/Cdc42 signal pathway.

    PubMed

    Chen, Mao-Liang; Tsai, Fu-Ming; Lee, Ming-Cheng; Lin, Yi-Yin

    2016-11-01

    Long-term administration of antipsychotic drugs (APDs) has been theorized to effect drug-induced changes in protein expression in the brain. Our previous findings revealed that ADPs can regulate Rho GDP-dissociation inhibitor 1 (RhoGDI1) expression in glial cells. To reveal whether APDs (haloperidol, risperidone, and clozapine) might regulate cell functions in rat brain by affecting RhoGDI1, RhoGDI1 regulation, RhoGDI1-related Rho family protein, and also MLC2 in brain of 7-day APD treatment rat were examined. Increased expression of RhoGDI1 and RhoA and decreased expression of MLC2, p-MLC2 and ARP2/3 were found in the cortex of APD-treated rats. The activation of RhoA in APD-treated rat cortex was also found. The regulation of RhoGDI1-induced protein expression and its relation to intracellular stress filament production and cell migration were further examined in APD-treated C6 and B35 cells. APD-induced RhoA expression and activation in C6 cells and Cdc42 expression and activation in B35 cells were investigated. In C6 cells, ARP2/3, ROCK1, pMLC2, and PFN1 expressions were decreased, and N-WASP expression was increased by any of the three APDs. In B35 cells, haloperidol decreased ROCK1 expression, but risperidone increased ROCK1 expression. MLC2, p-MLC2, and PFN1 expressions were decreased in B35 cells treated with either risperidone or clozapine. N-WASP expression was decreased by haloperidol and clozapine. We also found all three APDs enhance C6 and B35 F-actin condensation and migration ability. PMID:27302765

  8. Rho1 GTPase and PKC Ortholog Pck1 Are Upstream Activators of the Cell Integrity MAPK Pathway in Fission Yeast

    PubMed Central

    Sánchez-Mir, Laura; Soto, Teresa; Franco, Alejandro; Madrid, Marisa; Viana, Raúl A.; Vicente, Jero; Gacto, Mariano; Pérez, Pilar; Cansado, José

    2014-01-01

    In the fission yeast Schizosaccharomyces pombe the cell integrity pathway (CIP) orchestrates multiple biological processes like cell wall maintenance and ionic homeostasis by fine tuning activation of MAPK Pmk1 in response to various environmental conditions. The small GTPase Rho2 positively regulates the CIP through protein kinase C ortholog Pck2. However, Pmk1 retains some function in mutants lacking either Rho2 or Pck2, suggesting the existence of additional upstream regulatory elements to modulate its activity depending on the nature of the environmental stimulus. The essential GTPase Rho1 is a candidate to control the activity of the CIP by acting upstream of Pck2, whereas Pck1, a second PKC ortholog, appears to negatively regulate Pmk1 activity. However, the exact regulatory nature of these two proteins within the CIP has remained elusive. By exhaustive characterization of strains expressing a hypomorphic Rho1 allele (rho1-596) in different genetic backgrounds we show that both Rho1 and Pck1 are positive upstream regulatory members of the CIP in addition to Rho2 and Pck2. In this new model Rho1 and Rho2 control Pmk1 basal activity during vegetative growth mainly through Pck2. Notably, whereas Rho2-Pck2 elicit Pmk1 activation in response to most environmental stimuli, Rho1 drives Pmk1 activation through either Pck2 or Pck1 exclusively in response to cell wall damage. Our study reveals the intricate and complex functional architecture of the upstream elements participating in this signaling pathway as compared to similar routes from other simple eukaryotic organisms. PMID:24498240

  9. RhoB is a component of the human cytomegalovirus assembly complex and is required for efficient viral production

    PubMed Central

    Goulidaki, Nektaria; Alarifi, Saud; Alkahtani, Saad H; Al-Qahtani, Ahmed; Spandidos, Demetrios A; Stournaras, Christos; Sourvinos, George

    2015-01-01

    Human Cytomegalovirus (HCMV), an ubiquitous β-herpesvirus, is a significant pathogen that causes medically severe diseases in immunocompromised individuals and in congenitally infected neonates. RhoB belongs to the family of Rho GTPases, which regulates diverse cellular processes. Rho proteins are implicated in the entry and egress from the host cell of mainly α- and γ-herpesviruses, whereas β-herpesviruses are the least studied in this regard. Here, we studied the role of RhoB GTPase during HCMV lytic infection. Microscopy analysis, both in fixed and live infected cells showed that RhoB was translocated to the assembly complex/compartment (AC) of HCMV, a cytoplasmic zone in infected cells where many viral structural proteins are known to accumulate and assembly of new virions takes place. Furthermore, RhoB was localized at the AC even when the expression of the late HCMV AC proteins was inhibited. At the very late stages of infection, cellular projections were formed containing RhoB and HCMV virions, potentially contributing to the successful viral spread. Interestingly, the knockdown of RhoB in HCMV-infected cells resulted in a significant reduction of the virus titer and could also affect the accumulation of AC viral proteins at this subcellular compartment. RhoB knockdown also affected actin fibers' structure. Actin reorganization was observed at late stages of infection originating from the viral AC and surrounding the cellular projections, implying a potential interplay between RhoB and actin during HCMV assembly and egress. In conclusion, our results demonstrate for the first time that RhoB is a constituent of the viral AC and is required for HCMV productive infection. PMID:26114383

  10. Transcription Elongation Factor NusA Is a General Antagonist of Rho-dependent Termination in Escherichia coli.

    PubMed

    Qayyum, M Zuhaib; Dey, Debashish; Sen, Ranjan

    2016-04-01

    NusA is an essential protein that binds to RNA polymerase and also to the nascent RNA and influences transcription by inducing pausing and facilitating the process of transcription termination/antitermination. Its participation in Rho-dependent transcription termination has been perceived, but the molecular nature of this involvement is not known. We hypothesized that, because both Rho and NusA are RNA-binding proteins and have the potential to target the same RNA, the latter is likely to influence the global pattern of the Rho-dependent termination. Analyses of the nascent RNA binding properties and consequent effects on the Rho-dependent termination functions of specific NusA-RNA binding domain mutants revealed an existence of Rho-NusA direct competition for the overlappingnut(NusA-binding site) andrut(Rho-binding site) sites on the RNA. This leads to delayed entry of Rho at therutsite that inhibits the latter's RNA release process. High density tiling microarray profiles of these NusA mutants revealed that a significant number of genes, together with transcripts from intergenic regions, are up-regulated. Interestingly, the majority of these genes were also up-regulated when the Rho function was compromised. These results provide strong evidence for the existence of NusA-binding sites in different operons that are also the targets of Rho-dependent terminations. Our data strongly argue in favor of a direct competition between NusA and Rho for the access of specific sites on the nascent transcripts in different parts of the genome. We propose that this competition enables NusA to function as a global antagonist of the Rho function, which is unlike its role as a facilitator of hairpin-dependent termination. PMID:26872975

  11. Oxidized LDL signals through Rho-GTPase to induce endothelial cell stiffening and promote capillary formation.

    PubMed

    Oh, Myung-Jin; Zhang, Chongxu; LeMaster, Elizabeth; Adamos, Crystal; Berdyshev, Evgeny; Bogachkov, Yedida; Kohler, Erin E; Baruah, Jugajyoti; Fang, Yun; Schraufnagel, Dean E; Wary, Kishore K; Levitan, Irena

    2016-05-01

    Endothelial biomechanics is emerging as a key factor in endothelial function. Here, we address the mechanisms of endothelial stiffening induced by oxidized LDL (oxLDL) and investigate the role of oxLDL in lumen formation. We show that oxLDL-induced endothelial stiffening is mediated by CD36-dependent activation of RhoA and its downstream target, Rho kinase (ROCK), via inhibition of myosin light-chain phosphatase (MLCP) and myosin light-chain (MLC)2 phosphorylation. The LC-MS/MS analysis identifies 7-ketocholesterol (7KC) as the major oxysterol in oxLDL. Similarly to oxLDL, 7KC induces RhoA activation, MLCP inhibition, and MLC2 phosphorylation resulting in endothelial stiffening. OxLDL also facilitates formation of endothelial branching networks in 3D collagen gels in vitro and induces increased formation of functional blood vessels in a Matrigel plug assay in vivo. Both effects are RhoA and ROCK dependent. An increase in lumen formation was also observed in response to pre-exposing the cells to 7KC, an oxysterol that induces endothelial stiffening, but not to 5α,6α epoxide that does not affect endothelial stiffness. Importantly, loading cells with cholesterol prevented oxLDL-induced RhoA activation and the downstream signaling cascade, and reversed oxLDL-induced lumen formation. In summary, we show that oxLDL-induced endothelial stiffening is mediated by the CD36/RhoA/ROCK/MLCP/MLC2 pathway and is associated with increased endothelial angiogenic activity. PMID:26989083

  12. The Role of Ect2 Nuclear RhoGEF Activity in Ovarian Cancer Cell Transformation

    PubMed Central

    Huff, Lauren P.; DeCristo, Molly J.; Trembath, Dimitri; Kuan, Pei Fen; Yim, Margaret; Liu, Jinsong; Cook, Danielle R.; Miller, C. Ryan; Der, Channing J.

    2013-01-01

    Ect2, a Rho guanine nucleotide exchange factor (RhoGEF), is atypical among RhoGEFs in its predominantly nuclear localization in interphase cells. One current model suggests that Ect2 mislocalization drives cellular transformation by promoting aberrant activation of cytoplasmic Rho family GTPase substrates. However, in ovarian cancers, where Ect2 is both amplified and overexpressed at the mRNA level, we observed that the protein is highly expressed and predominantly nuclear and that nuclear but not cytoplasmic Ect2 increases with advanced disease. Knockdown of Ect2 in ovarian cancer cell lines impaired their anchorage-independent growth without affecting their growth on plastic. Restoration of Ect2 expression rescued the anchorage-independent growth defect, but not if either the DH catalytic domain or the nuclear localization sequences of Ect2 were mutated. These results suggested a novel mechanism whereby Ect2 could drive transformation in ovarian cancer cells by acting as a RhoGEF specifically within the nucleus. Interestingly, Ect2 had an intrinsically distinct GTPase specificity profile in the nucleus versus the cytoplasm. Nuclear Ect2 bound preferentially to Rac1, while cytoplasmic Ect2 bound to RhoA but not Rac. Consistent with nuclear activation of endogenous Rac, Ect2 overexpression was sufficient to recruit Rac effectors to the nucleus, a process that required a functional Ect2 catalytic domain. Furthermore, expression of active nuclearly targeted Rac1 rescued the defect in transformed growth caused by Ect2 knockdown. Our work suggests a novel mechanism of Ect2-driven transformation, identifies subcellular localization as a regulator of GEF specificity, and implicates activation of nuclear Rac1 in cellular transformation. PMID:24386507

  13. Regulation of plasticity and fibrogenic activity of trabecular meshwork cells by Rho GTPase signaling.

    PubMed

    Pattabiraman, Padmanabhan P; Maddala, Rupalatha; Rao, Ponugoti Vasantha

    2014-07-01

    Glaucoma, a prevalent blinding disease is commonly associated with increased intraocular pressure due to impaired aqueous humor (AH) drainage through the trabecular meshwork (TM). Although increased TM tissue contraction and stiffness in association with accumulation of extracellular matrix (ECM) are believed to be partly responsible for increased resistance to AH outflow, the extracellular cues and intracellular mechanisms regulating TM cell contraction and ECM production are not well defined. This study tested the hypothesis that sustained activation of Rho GTPase signaling induced by lysophosphatidic acid (LPA), TGF-β, and connective tissue growth factor (CTGF) influences TM cell plasticity and fibrogenic activity which may eventually impact resistance to AH outflow. Various experiments performed using human TM cells revealed that constitutively active RhoA (RhoAV14), TGF-β2, LPA, and CTGF significantly increase the levels and expression of Fibroblast Specific Protein-1 (FSP-1), α-smooth muscle actin (αSMA), collagen-1A1 and secretory total collagen, as determined by q-RT-PCR, immunofluorescence, immunoblot, flow cytometry and the Sircol assay. Significantly, these changes appear to be mediated by Serum Response Factor (SRF), myocardin-related transcription factor (MRTF-A), Slug, and Twist-1, which are transcriptional regulators known to control cell plasticity, myofibroblast generation/activation and fibrogenic activity. Additionally, the Rho kinase inhibitor-Y27632 and anti-fibrotic agent-pirfenidone were both found to suppress the TGF-β2-induced expression of αSMA, FSP-1, and collagen-1A1. Taken together, these observations demonstrate the significance of RhoA/Rho kinase signaling in regulation of TM cell plasticity, fibrogenic activity, and myofibroblast activation, events with potential implications for the pathobiology of elevated intraocular pressure in glaucoma patients. PMID:24318513

  14. Alpha-thalassaemia.

    PubMed

    Harteveld, Cornelis L; Higgs, Douglas R

    2010-01-01

    Alpha-thalassaemia is inherited as an autosomal recessive disorder characterised by a microcytic hypochromic anaemia, and a clinical phenotype varying from almost asymptomatic to a lethal haemolytic anaemia.It is probably the most common monogenic gene disorder in the world and is especially frequent in Mediterranean countries, South-East Asia, Africa, the Middle East and in the Indian subcontinent. During the last few decades the incidence of alpha thalassaemia in North-European countries and Northern America has increased because of demographic changes. Compound heterozygotes and some homozygotes have a moderate to severe form of alpha thalassaemia called HbH disease. Hb Bart's hydrops foetalis is a lethal form in which no alpha-globin is synthesized. Alpha thalassaemia most frequently results from deletion of one or both alpha genes from the chromosome and can be classified according to its genotype/phenotype correlation. The normal complement of four functional alpha-globin genes may be decreased by 1, 2, 3 or all 4 copies of the genes, explaining the clinical variation and increasing severity of the disease. All affected individuals have a variable degree of anaemia (low Hb), reduced mean corpuscular haemoglobin (MCH/pg), reduced mean corpuscular volume (MCV/fl) and a normal/slightly reduced level of HbA2. Molecular analysis is usually required to confirm the haematological observations (especially in silent alpha-thalassaemia and alpha-thalassaemia trait). The predominant features in HbH disease are anaemia with variable amounts of HbH (0.8-40%). The type of mutation influences the clinical severity of HbH disease. The distinguishing features of the haemoglobin Bart's hydrops foetalis syndrome are the presence of Hb Bart's and the total absence of HbF. The mode of transmission of alpha thalassaemia is autosomal recessive. Genetic counselling is offered to couples at risk for HbH disease or haemoglobin Bart's Hydrops Foetalis Syndrome. Carriers of alpha+- or

  15. MgcRacGAP restricts active RhoA at the cytokinetic furrow and both RhoA and Rac1 at cell–cell junctions in epithelial cells

    PubMed Central

    Breznau, Elaina B.; Semack, Ansley C.; Higashi, Tomohito; Miller, Ann L.

    2015-01-01

    Localized activation of Rho GTPases is essential for multiple cellular functions, including cytokinesis and formation and maintenance of cell–cell junctions. Although MgcRacGAP (Mgc) is required for spatially confined RhoA-GTP at the equatorial cortex of dividing cells, both the target specificity of Mgc's GAP activity and the involvement of phosphorylation of Mgc at Ser-386 are controversial. In addition, Mgc's function at cell–cell junctions remains unclear. Here, using gastrula-stage Xenopus laevis embryos as a model system, we examine Mgc's role in regulating localized RhoA-GTP and Rac1-GTP in the intact vertebrate epithelium. We show that Mgc's GAP activity spatially restricts accumulation of both RhoA-GTP and Rac1-GTP in epithelial cells—RhoA at the cleavage furrow and RhoA and Rac1 at cell–cell junctions. Phosphorylation at Ser-386 does not switch the specificity of Mgc's GAP activity and is not required for successful cytokinesis. Furthermore, Mgc regulates adherens junction but not tight junction structure, and the ability to regulate adherens junctions is dependent on GAP activity and signaling via the RhoA pathway. Together these results indicate that Mgc's GAP activity down-regulates the active populations of RhoA and Rac1 at localized regions of epithelial cells and is necessary for successful cytokinesis and cell–cell junction structure. PMID:25947135

  16. Monitoring conformational dynamics with solid-state R 1rho experiments.

    PubMed

    Quinn, Caitlin M; McDermott, Ann E

    2009-09-01

    A new application of solid-state rotating frame (R(1rho)) relaxation experiments to observe conformational dynamics is presented. Studies on a model compound, dimethyl sulfone (DMS), show that R(1rho) relaxation due to reorientation of a chemical shift anisotropy (CSA) tensor undergoing chemical exchange can be used to monitor slow-to-intermediate timescale conformational exchange processes. Control experiments used d ( 6 ) -DMS and alanine to confirm that the technique is monitoring reorientation of the CSA tensor rather than dipolar interactions or methyl group rotation. The application of this method to proteins could represent a new site-specific probe of conformational dynamics. PMID:19636799

  17. Angular distributions in J/{psi}({rho}{sup 0},{omega}) states near threshold

    SciTech Connect

    Rosner, Jonathan L.

    2004-11-01

    A resonance X(3872), first observed in the decays B{yields}KX, has been seen to decay to J/{psi}{pi}{sup +}{pi}{sup -}. The {pi}{sup +}{pi}{sup -} mass spectrum peaks near its kinematic upper limit, prompting speculation that the dipion system may be in a {rho}{sup 0}. The decay X(3872){yields}J/{psi}{omega} also has been observed. The reaction {gamma}{gamma}{yields}J/{psi}{pi}{sup +}{pi}{sup -} has been studied. Consequently, angular distributions in decays of J/{psi}({rho}{sup 0},{omega}) states near threshold are of interest, and results are presented.

  18. Eukaryotic Translation Initiation Factor 5A (EIF5A) Regulates Pancreatic Cancer Metastasis by Modulating RhoA and Rho-associated Kinase (ROCK) Protein Expression Levels.

    PubMed

    Fujimura, Ken; Choi, Sunkyu; Wyse, Meghan; Strnadel, Jan; Wright, Tracy; Klemke, Richard

    2015-12-11

    Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with an overall survival rate of less than 5%. The poor patient outcome in PDAC is largely due to the high prevalence of systemic metastasis at the time of diagnosis and lack of effective therapeutics that target disseminated cells. The fact that the underlying mechanisms driving PDAC cell migration and dissemination are poorly understood have hindered drug development and compounded the lack of clinical success in this disease. Recent evidence indicates that mutational activation of K-Ras up-regulates eIF5A, a component of the cellular translational machinery that is critical for PDAC progression. However, the role of eIF5A in PDAC cell migration and metastasis has not been investigated. We report here that pharmacological inhibition or genetic knockdown of eIF5A reduces PDAC cell migration, invasion, and metastasis in vitro and in vivo. Proteomic profiling and bioinformatic analyses revealed that eIF5A controls an integrated network of cytoskeleton-regulatory proteins involved in cell migration. Functional interrogation of this network uncovered a critical RhoA/ROCK signaling node that operates downstream of eIF5A in invasive PDAC cells. Importantly, eIF5A mediates PDAC cell migration and invasion by modulating RhoA/ROCK protein expression levels. Together our findings implicate eIF5A as a cytoskeletal rheostat controlling RhoA/ROCK protein expression during PDAC cell migration and metastasis. Our findings also implicate the eIF5A/RhoA/ROCK module as a potential new therapeutic target to treat metastatic PDAC cells. PMID:26483550

  19. The absence of a mitochondrial genome in rho0 yeast cells extends lifespan independently of retrograde regulation

    PubMed Central

    Woo, Dong Kyun; Poyton, Robert O.

    2009-01-01

    The absence of mtDNA in rho0 yeast cells affects both respiration and mitochondrial-nuclear communication (e.g., retrograde regulation, intergenomic signaling, or pleiotropic drug resistance). Previously, it has been reported that some rho0 strains have increased replicative lifespans, attributable to the lack of respiration and retrograde regulation. Here, we have been able to confirm that rho0 cells exhibit increased replicative lifespans but have found that this is not associated with the lack of respiration or reduced oxidative stress but instead, is related to the lack of mtDNA per se in rho0 cells. Also, we find no correlation between the strength of retrograde regulation and lifespan. Furthermore, we find that pdr3- or rtg2- mutations are not responsible for lifespan extension in rho0 cells, ruling out a specific role for PDR3-pleiotropic drug resistance or RGT2-retrograde regulation pathways in the extended lifespans of rho0 cells. Surprisingly, Rtg3p, which acts downstream of Rtg2p, is required for lifespan increase in rho0 cells. Together, these findings indicate that the loss of mtDNA per se and not the lack of respiration lead to extended longevity in rho0 cells. They also suggest that Rtg3p, acting independently of retrograde regulation, mediates this effect, possibly via intergenomic signaling. PMID:19285548

  20. Distinct roles of Rho1, Cdc42, and Cyk3 in septum formation and abscission during yeast cytokinesis

    PubMed Central

    Onishi, Masayuki; Ko, Nolan; Nishihama, Ryuichi

    2013-01-01

    In yeast and animal cytokinesis, the small guanosine triphosphatase (GTPase) Rho1/RhoA has an established role in formation of the contractile actomyosin ring, but its role, if any, during cleavage-furrow ingression and abscission is poorly understood. Through genetic screens in yeast, we found that either activation of Rho1 or inactivation of another small GTPase, Cdc42, promoted secondary septum (SS) formation, which appeared to be responsible for abscission. Consistent with this hypothesis, a dominant-negative Rho1 inhibited SS formation but not cleavage-furrow ingression or the concomitant actomyosin ring constriction. Moreover, Rho1 is temporarily inactivated during cleavage-furrow ingression; this inactivation requires the protein Cyk3, which binds Rho1-guanosine diphosphate via its catalytically inactive transglutaminase-like domain. Thus, unlike the active transglutaminases that activate RhoA, the multidomain protein Cyk3 appears to inhibit activation of Rho1 (and thus SS formation), while simultaneously promoting cleavage-furrow ingression through primary septum formation. This work suggests a general role for the catalytically inactive transglutaminases of fungi and animals, some of which have previously been implicated in cytokinesis. PMID:23878277

  1. Viral vector-mediated downregulation of RhoA increases survival and axonal regeneration of retinal ganglion cells

    PubMed Central

    Koch, Jan Christoph; Tönges, Lars; Michel, Uwe; Bähr, Mathias; Lingor, Paul

    2014-01-01

    The Rho/ROCK pathway is a promising therapeutic target in neurodegenerative and neurotraumatic diseases. Pharmacological inhibition of various pathway members has been shown to promote neuronal regeneration and survival. However, because pharmacological inhibitors are inherently limited in their specificity, shRNA-mediated approaches can add more information on the function of each single kinase involved. Thus, we generated adeno-associated viral vectors (AAV) to specifically downregulate Ras homologous member A (RhoA) via shRNA. We found that specific knockdown of RhoA promoted neurite outgrowth of retinal ganglion cells (RGC) grown on the inhibitory substrate chondroitin sulfate proteoglycan (CSPG) as well as neurite regeneration of primary midbrain neurons (PMN) after scratch lesion. In the rat optic nerve crush (ONC) model in vivo, downregulation of RhoA significantly enhanced axonal regeneration compared to control. Moreover, survival of RGC transduced with AAV expressing RhoA-shRNA was substantially increased at 2 weeks after optic nerve axotomy. Compared to previous data using pharmacological inhibitors to target RhoA, its upstream regulator Nogo or its main downstream target ROCK, the specific effects of RhoA downregulation shown here were most pronounced in regard to promoting RGC survival but neurite outgrowth and axonal regeneration were also increased significantly. Taken together, we show here that specific knockdown of RhoA substantially increases neuronal survival after optic nerve axotomy and modestly increases neurite outgrowth in vitro and axonal regeneration after optic nerve crush. PMID:25249936

  2. A Point Mutation in p190A RhoGAP Affects Ciliogenesis and Leads to Glomerulocystic Kidney Defects

    PubMed Central

    Shafer, Maxwell E. R.; Aoudjit, Lamine; Hu, Di; Sharma, Richa; Tremblay, Mathieu; Ishii, Hidetaka; Marcotte, Michael; Stanga, Daniela; Tang, You Chi; Boualia, Sami Kamel; Nguyen, Alana H. T.; Takano, Tomoko; Lamarche-Vane, Nathalie; Vidal, Silvia; Bouchard, Maxime

    2016-01-01

    Rho family GTPases act as molecular switches regulating actin cytoskeleton dynamics. Attenuation of their signaling capacity is provided by GTPase-activating proteins (GAPs), including p190A, that promote the intrinsic GTPase activity of Rho proteins. In the current study we have performed a small-scale ENU mutagenesis screen and identified a novel loss of function allele of the p190A gene Arhgap35, which introduces a Leu1396 to Gln substitution in the GAP domain. This results in decreased GAP activity for the prototypical Rho-family members, RhoA and Rac1, likely due to disrupted ordering of the Rho binding surface. Consequently, Arhgap35-deficient animals exhibit hypoplastic and glomerulocystic kidneys. Investigation into the cystic phenotype shows that p190A is required for appropriate primary cilium formation in renal nephrons. P190A specifically localizes to the base of the cilia to permit axoneme elongation, which requires a functional GAP domain. Pharmacological manipulations further reveal that inhibition of either Rho kinase (ROCK) or F-actin polymerization is able to rescue the ciliogenesis defects observed upon loss of p190A activity. We propose a model in which p190A acts as a modulator of Rho GTPases in a localized area around the cilia to permit the dynamic actin rearrangement required for cilia elongation. Together, our results establish an unexpected link between Rho GTPase regulation, ciliogenesis and glomerulocystic kidney disease. PMID:26859289

  3. The SH3/PH domain protein AgBoi1/2 collaborates with the Rho-type GTPase AgRho3 to prevent nonpolar growth at hyphal tips of Ashbya gossypii.

    PubMed

    Knechtle, Philipp; Wendland, Jürgen; Philippsen, Peter

    2006-10-01

    Unlike most other cells, hyphae of filamentous fungi permanently elongate and lack nonpolar growth phases. We identified AgBoi1/2p in the filamentous ascomycete Ashbya gossypii as a component required to prevent nonpolar growth at hyphal tips. Strains lacking AgBoi1/2p frequently show spherical enlargement at hyphal tips with concomitant depolarization of actin patches and loss of tip-located actin cables. These enlarged tips can repolarize and resume hyphal tip extension in the previous polarity axis. AgBoi1/2p permanently localizes to hyphal tips and transiently to sites of septation. Only the tip localization is important for sustained elongation of hyphae. In a yeast two-hybrid experiment, we identified the Rho-type GTPase AgRho3p as an interactor of AgBoi1/2p. AgRho3p is also required to prevent nonpolar growth at hyphal tips, and strains deleted for both AgBOI1/2 and AgRHO3 phenocopied the respective single-deletion strains, demonstrating that AgBoi1/2p and AgRho3p function in a common pathway. Monitoring the polarisome of growing hyphae using AgSpa2p fused to the green fluorescent protein as a marker, we found that polarisome disassembly precedes the onset of nonpolar growth in strains lacking AgBoi1/2p or AgRho3p. AgRho3p locked in its GTP-bound form interacts with the Rho-binding domain of the polarisome-associated formin AgBni1p, implying that AgRho3p has the capacity to directly activate formin-driven actin cable nucleation. We conclude that AgBoi1/2p and AgRho3p support polarisome-mediated actin cable formation at hyphal tips, thereby ensuring permanent polar tip growth. PMID:16950929

  4. Alpha Particle Diagnostic

    SciTech Connect

    Fisher, Ray, K.

    2009-05-13

    The study of burning plasmas is the next frontier in fusion energy research, and will be a major objective of the U.S. fusion program through U.S. collaboration with our international partners on the ITER Project. For DT magnetic fusion to be useful for energy production, it is essential that the energetic alpha particles produced by the fusion reactions be confined long enough to deposit a significant fraction of their initial ~3.5 MeV energy in the plasma before they are lost. Development of diagnostics to study the behavior of energetic confined alpha particles is a very important if not essential part of burning plasma research. Despite the clear need for these measurements, development of diagnostics to study confined the fast confined alphas to date has proven extremely difficult, and the available techniques remain for the most part unproven and with significant uncertainties. Research under this grant had the goal of developing diagnostics of fast confined alphas, primarily based on measurements of the neutron and ion tails resulting from alpha particle knock-on collisions with the plasma deuterium and tritium fuel ions. One of the strengths of this approach is the ability to measure the alphas in the hot plasma core where the interesting ignition physics will occur.

  5. Sip1, an AP-1 accessory protein in fission yeast, is required for localization of Rho3 GTPase.

    PubMed

    Yu, Yang; Li, Cuifang; Kita, Ayako; Katayama, Yuta; Kubouchi, Koji; Udo, Masako; Imanaka, Yukako; Ueda, Shiho; Masuko, Takashi; Sugiura, Reiko

    2013-01-01

    Rho family GTPases act as molecular switches to regulate a range of physiological functions, including the regulation of the actin-based cytoskeleton, membrane trafficking, cell morphology, nuclear gene expression, and cell growth. Rho function is regulated by its ability to bind GTP and by its localization. We previously demonstrated functional and physical interactions between Rho3 and the clathrin-associated adaptor protein-1 (AP-1) complex, which revealed a role of Rho3 in regulating Golgi/endosomal trafficking in fission yeast. Sip1, a conserved AP-1 accessory protein, recruits the AP-1 complex to the Golgi/endosomes through physical interaction. In this study, we showed that Sip1 is required for Rho3 localization. First, overexpression of rho3⁺ suppressed defective membrane trafficking associated with sip1-i4 mutant cells, including defects in vacuolar fusion, Golgi/endosomal trafficking and secretion. Notably, Sip1 interacted with Rho3, and GFP-Rho3, similar to Apm1-GFP, did not properly localize to the Golgi/endosomes in sip1-i4 mutant cells at 27°C. Interestingly, the C-terminal region of Sip1 is required for its localization to the Golgi/endosomes, because Sip1-i4-GFP protein failed to properly localize to Golgi/endosomes, whereas the fluorescence of Sip1ΔN mutant protein co-localized with that of FM4-64. Consistently, in the sip1-i4 mutant cells, which lack the C-terminal region of Sip1, binding between Apm1 and Rho3 was greatly impaired, presumably due to mislocalization of these proteins in the sip1-i4 mutant cells. Furthermore, the interaction between Apm1 and Rho3 as well as Rho3 localization to the Golgi/endosomes were significantly rescued in sip1-i4 mutant cells by the expression of Sip1ΔN. Taken together, these results suggest that Sip1 recruits Rho3 to the Golgi/endosomes through physical interaction and enhances the formation of the Golgi/endosome AP-1/Rho3 complex, thereby promoting crosstalk between AP-1 and Rho3 in the regulation of

  6. Sip1, an AP-1 Accessory Protein in Fission Yeast, Is Required for Localization of Rho3 GTPase

    PubMed Central

    Yu, Yang; Li, Cuifang; Kita, Ayako; Katayama, Yuta; Kubouchi, Koji; Udo, Masako; Imanaka, Yukako; Ueda, Shiho; Masuko, Takashi; Sugiura, Reiko

    2013-01-01

    Rho family GTPases act as molecular switches to regulate a range of physiological functions, including the regulation of the actin-based cytoskeleton, membrane trafficking, cell morphology, nuclear gene expression, and cell growth. Rho function is regulated by its ability to bind GTP and by its localization. We previously demonstrated functional and physical interactions between Rho3 and the clathrin-associated adaptor protein-1 (AP-1) complex, which revealed a role of Rho3 in regulating Golgi/endosomal trafficking in fission yeast. Sip1, a conserved AP-1 accessory protein, recruits the AP-1 complex to the Golgi/endosomes through physical interaction. In this study, we showed that Sip1 is required for Rho3 localization. First, overexpression of rho3+ suppressed defective membrane trafficking associated with sip1-i4 mutant cells, including defects in vacuolar fusion, Golgi/endosomal trafficking and secretion. Notably, Sip1 interacted with Rho3, and GFP-Rho3, similar to Apm1-GFP, did not properly localize to the Golgi/endosomes in sip1-i4 mutant cells at 27°C. Interestingly, the C-terminal region of Sip1 is required for its localization to the Golgi/endosomes, because Sip1-i4-GFP protein failed to properly localize to Golgi/endosomes, whereas the fluorescence of Sip1ΔN mutant protein co-localized with that of FM4-64. Consistently, in the sip1-i4 mutant cells, which lack the C-terminal region of Sip1, binding between Apm1 and Rho3 was greatly impaired, presumably due to mislocalization of these proteins in the sip1-i4 mutant cells. Furthermore, the interaction between Apm1 and Rho3 as well as Rho3 localization to the Golgi/endosomes were significantly rescued in sip1-i4 mutant cells by the expression of Sip1ΔN. Taken together, these results suggest that Sip1 recruits Rho3 to the Golgi/endosomes through physical interaction and enhances the formation of the Golgi/endosome AP-1/Rho3 complex, thereby promoting crosstalk between AP-1 and Rho3 in the regulation of Golgi

  7. RhoBTB2 (DBC2) functions as a multifunctional tumor suppressor in thyroid cancer cells via mitochondrial apoptotic pathway

    PubMed Central

    Wang, Chuan-Jiang; Yang, Dong; Luo, Ying-Wei

    2015-01-01

    Thyroid cancer is the most common endocrine malignancy worldwide. Tumor suppressor gene RhoBTB2 (also known as Deleted in Breast Cancer 2, DBC2) was observed in various carcinomas, however, no reports showed the effects of RhoBTB2 on thyroid cancer. In our study, we found that RhoBTB2 decreases proliferation, increases apoptosis, inhibits mobility, and induces mitochondria damage in SW579 cells through increased Bax and decreased Bcl-2 and Bcl-xL protein expression. The effects of RhoBTB2 on SW579 cells were inversed by using butin (an inhibitor of the mitochondrial apoptosis pathway). Our results suggest that RhoBTB2 suppresses the growth of SW579 cells through a mitochondrial apoptosis pathway. PMID:26131191

  8. Radiation-Induced RhoGDIβ Cleavage Leads to Perturbation of Cell Polarity: A Possible Link to Cancer Spreading.

    PubMed

    Fujiwara, Mamoru; Okamoto, Mayumi; Hori, Masato; Suga, Hiroshi; Jikihara, Hiroshi; Sugihara, Yuka; Shimamoto, Fumio; Mori, Toshio; Nakaoji, Koichi; Hamada, Kazuhiko; Ota, Takahide; Wiedemuth, Ralf; Temme, Achim; Tatsuka, Masaaki

    2016-11-01

    The equilibrium between proliferation and apoptosis is tightly balanced to maintain tissue homeostasis in normal tissues and even in tumors. Achieving and maintaining such a balance is important for cancer regrowth and spreading after cytotoxic treatments. Caspase-3 activation and tumor cell death following anticancer therapy as well as accompanying cell death pathways are well characterized, but their association to homeostasis of cancerous tissue and tumor progression remains poorly understood. Here we proposed a novel mechanism of cancer spreading induced by caspase-3. RhoGDIβ, known as a direct cleavage substrate of caspase-3, is overexpressed in many epithelial cancers. The N-terminal-truncated RhoGDIβ (ΔN-RhoGDIβ) is accumulated in caspase-3-activated cells. Stable expression of ΔN-RhoGDIβ in HeLa cells did not induce apoptosis, but impaired directional cell migration in a wound-healing assay accompanied by a perturbed direction of cell division at the wound edge. Subcellular protein fractionation experiments revealed that ΔN-RhoGDIβ but not wild-type RhoGDIβ was present in the detergent-soluble cytoplasmic and nuclear fractions and preferentially associated with Cdc42. Furthermore, Cdc42 activity was constitutively inhibited by stable expression of ΔN-RhoGDIβ, resulting in increased radiation-induced compensatory proliferation linking to RhoA activation. Thus, ΔN-RhoGDIβ dominant-negatively regulates Cdc42 activity and contributes to loss of polarity-related functions. The caspase-3-cleaved RhoGDIβ is a possible determinant to promote cancer spreading due to deregulation of directional organization of tumor cell population and inhibition of default equilibrium between proliferation and apoptosis after cytotoxic damage. J. Cell. Physiol. 231: 2493-2505, 2016. © 2016 Wiley Periodicals, Inc. PMID:26919575

  9. Automated NMR Fragment Based Screening Identified a Novel Interface Blocker to the LARG/RhoA Complex

    PubMed Central

    Gao, Jia; Ma, Rongsheng; Wang, Wei; Wang, Na; Sasaki, Ryan; Snyderman, David; Wu, Jihui; Ruan, Ke

    2014-01-01

    The small GTPase cycles between the inactive GDP form and the activated GTP form, catalyzed by the upstream guanine exchange factors. The modulation of such process by small molecules has been proven to be a fruitful route for therapeutic intervention to prevent the over-activation of the small GTPase. The fragment based approach emerging in the past decade has demonstrated its paramount potential in the discovery of inhibitors targeting such novel and challenging protein-protein interactions. The details regarding the procedure of NMR fragment screening from scratch have been rarely disclosed comprehensively, thus restricts its wider applications. To achieve a consistent screening applicable to a number of targets, we developed a highly automated protocol to cover every aspect of NMR fragment screening as possible, including the construction of small but diverse libray, determination of the aqueous solubility by NMR, grouping compounds with mutual dispersity to a cocktail, and the automated processing and visualization of the ligand based screening spectra. We exemplified our streamlined screening in RhoA alone and the complex of the small GTPase RhoA and its upstream guanine exchange factor LARG. Two hits were confirmed from the primary screening in cocktail and secondary screening over individual hits for LARG/RhoA complex, while one of them was also identified from the screening for RhoA alone. HSQC titration of the two hits over RhoA and LARG alone, respectively, identified one compound binding to RhoA.GDP at a 0.11 mM affinity, and perturbed the residues at the switch II region of RhoA. This hit blocked the formation of the LARG/RhoA complex, validated by the native gel electrophoresis, and the titration of RhoA to 15N labeled LARG in the absence and presence the compound, respectively. It therefore provides us a starting point toward a more potent inhibitor to RhoA activation catalyzed by LARG. PMID:24505392

  10. Role of RhoA/ROCK-dependent actin contractility in the induction of tenascin-C by cyclic tensile strain.

    PubMed

    Sarasa-Renedo, Ana; Tunç-Civelek, Vildan; Chiquet, Matthias

    2006-05-01

    In chick embryo fibroblasts, the mRNA for extracellular matrix protein tenascin-C is induced 2-fold by cyclic strain (10%, 0.3 Hz, 6 h). This response is attenuated by inhibiting Rho-dependent kinase (ROCK). The RhoA/ROCK signaling pathway is primarily involved in actin dynamics. Here, we demonstrate its crucial importance in regulating tenascin-C expression. Cyclic strain stimulated RhoA activation and induced fibroblast contraction. Chemical activators of RhoA synergistically enhanced the effects of cyclic strain on cell contractility. Interestingly, tenascin-C mRNA levels perfectly matched the extent of RhoA/ROCK-mediated actin contraction. First, RhoA activation by thrombin, lysophosphatidic acid, or colchicine induced tenascin-C mRNA to a similar extent as strain. Second, RhoA activating drugs in combination with cyclic strain caused a super-induction (4- to 5-fold) of tenascin-C mRNA, which was again suppressed by ROCK inhibition. Third, disruption of the actin cytoskeleton with latrunculin A abolished induction of tenascin-C mRNA by chemical RhoA activators in combination with cyclic strain. Lastly, we found that myosin II activity is required for tenascin-C induction by cyclic strain. We conclude that RhoA/ROCK-controlled actin contractility has a mechanosensory function in fibroblasts that correlates directly with tenascin-C gene expression. Previous RhoA/ROCK activation, either by chemical or mechanical signals, might render fibroblasts more sensitive to external tensile stress, e.g., during wound healing. PMID:16448650

  11. Potential drug interaction between Rho(D) immune globulin and live virus vaccine.

    PubMed

    Holmes, Amy; Wright, Debra

    2014-12-01

    Women often receive Rho(D) immune globulin as well as a live virus vaccine in the immediate postpartum period. The immune globulin product has the potential to interfere with appropriate immune response to the vaccine. Here we describe our approach to identifying and following up on this often overlooked potential drug interaction. PMID:25495973

  12. Infralimbic cortex Rho-kinase inhibition causes antidepressant-like activity in rats.

    PubMed

    Inan, Salim Yalcin; Soner, Burak Cem; Sahin, Ayse Saide

    2015-03-01

    Depression is one of the most common psychiatric disorders in the world; however, its mechanisms remain unclear. Recently, a new signal-transduction pathway, namely Rho/Rho-kinase signalling, has been suggested to be involved in diverse cellular events in the central nervous system; such as epilepsy, anxiety-related behaviors, regulation of dendritic and axonal morphology, antinociception, subarachnoid haemorrhage, spinal cord injury and amyotrophic lateral sclerosis. However there is no evidence showing the involvement of Rho-kinase pathway in depression. In addition, the infralimbic cortex, rodent equivalent to subgenual cingulate cortex has been shown to be responsible for emotional responses. Thus, in the present study, intracranial guide cannulae were stereotaxically implanted bilaterally into the infralimbic cortex, and the effects of repeated microinjections of a Rho-kinase (ROCK) inhibitor Y-27632 (10 nmol) were investigated in rats. Y-27632 significantly decreased immobility time and increased swimming and climbing behaviors when compared to fluoxetine (10 μg) and saline groups in the forced swim test. In addition, Y-27632 treatment did not affect spontaneous locomotor activity and forelimb use in the open-field and cylinder tests respectively; but it enhanced limb placing accuracy in the ladder rung walking test. Our results suggest that Y-27632 could be a potentially active antidepressant agent. PMID:25445474

  13. Measurements of B meson decays to (omega)K* and (omega)(rho)

    SciTech Connect

    Aubert, B; Cheng, C H; Lange, D J; Simani, M C; . Wright, D M; Abrams, G S; Borgland, A W; Breon, A B; Brown, D N; Button-Shafer, J; Cahn, R H; Charles, E; Day, C T; Gill, M S; Gritsan, A V; Groysman, Y; Jacobsen, R G; Kadel, R W; Kadyk, J; Kerth, L T; Kolomensky, Y G; Kukartsev, G; Lynch, G; Mir, L M; Oddone, P J; Orimoto, T J; Pripstein, M; Roe, N A; Ronan, M T; Wenzel, W A; Abe, T; Aston, D; Bartoldus, R; Berger, N; Boyarski, A M; Buchmueller, O L; Claus, R; Convery, M R; Cristinziani, M; De Nardo, G; Dong, D; Dorfan, J; Dujmic, D; Dunwoodie, W; Fan, S; Field, R C; Glanzman, T; Gowdy, S J; Hadig, T; Halyo, V; Hast, C; Hryn'ova, T; Innes, W R; Kelsey, M H; Kim, P; Kocian, M L; Keith, D W . S; Libby, J; Luitz, S; Luth, V; Lynch, H L; Marsiske, H; Messner, R; Muller, D R; O'Grady, C P; Ozcan, V E; Perazzo, A; Perl, M; Petrak, S; Ratcliff, B N; Roodman, A; Salnikov, A A; Schindler, R H; Schwiening, J; Snyder, A; Soha, A; Stelzer, H; Strube, J; Su, D; Sullivan, M K; Va'vra, J; Wagner, S R; Weaver, M; Wisniewski, W J; Wittgen, M; Wright, D H; Yarritu, A K; Young, C C; Collaboration, B

    2006-03-14

    The authors describe searches for B meson decays to the charmless vector-vector final states {omega}K* and {omega}{rho} in 89 million B{bar B} pairs produced in e{sup +}e{sup -} annihilation at {radical}s = 10.58 GeV.

  14. On the Mass Difference Between pi and rho Using a Relativistic Two-Body Model

    SciTech Connect

    Wong, Cheuk-Yin; Kim, Byeong-Noh; Crater, H. W.; Yoon, Jin-Hee

    2012-01-01

    The big mass difference between the pion(pi) and rho meson(rho) possibly originated from the spin-dependent nature of the interactions in the two states since these two states are similar except for spin. Both pi and rho are quark-antiquark systems which can be treated using the two-body Dirac equations (TBDE) of constraint dynamics. This relativistic approach for the two-body system has the advantage over the non-relativistic treatment in the sense that the spin-dependent nature is automatically coming out from the formalism. We employed Dirac's relativistic constraint dynamics to describe quark-antiquark systems. Within this formalism, the 16-component Dirac equation is reduced to the 4-component 2nd-order differential equation and the radial part of this equation is simply a Schroedinger-type equation with various terms calculated from the basic radial potential. We used a modified Richardson potential for quark-antiquark systems which satisfies the conditions of confinement and asymptotic freedom. We obtained the wave functions for these two mesons which are not singular at short distances. We also found that the cancellation between the Darwin and spin-spin interaction terms occurs in the pi mass but not in the rho mass, and this is the main source of the big difference in the two meson masses.

  15. Photoproduction of an isovector. rho. pi. state at 1775 MeV

    SciTech Connect

    Condo, G.T.; Handler, T.; Shimony, J.; Abe, K.; Armenteros, R.; Austern, M.; Bacon, T.C.; Ballam, J.; Bingham, H.H.; Brau, J.E.; Braune, K.; Brick, D.; Bugg, W.M.; Butler, J.M.; Cameron, W.; Cohn, H.O.; Colley, D.C.; Dado, S.; Diamond, R.; Dingus, P.; Erickson, R.; Falicov, A.; Field, R.C.; Fortney, L.R.; Franek, B.; Fujiwara, N.; Glanzman, T.; Godfrey, I.M.; Goldberg, J.J.; Goshaw, A.T.; Hall, G.; Hancock, E.R.; Hargis, H.J.; Hart, E.L.; Harwin, M.J.; Hasegawa, K.; Hulsizer, R.I.; Jobes, M.; Kafka, T.; Kalmus, G.E.; Kelsey, D.P.; Kent, J.; Kitagaki, T.; Levy, A.; Lucas, P.W.; Mann, W.A.; McCrory, E.S.; Merenyi, R.; Milburn, R.; Milstene, C.; Moffeit, K.C.; Napier, A.; Noguchi, S.; O'Dell, V.R.; O'Neale, S.; Palounek, A.P.T.; Pless, I.A.; Rankin, P.; Robertson, W.J.; Sagawa, H.; Sato, T.; Schneps, J.; Sewell, S.J.; Shank, J.; Shapiro, A.M.; Sugahara, R.; Takahashi, K.; Tamai, K.; Tanaka, S.; Tether, S.; Waide, D.A.; Walker, W.D.; White, S.L.; Widgoff, M.; Wilkins, C.G.; Wolbers, S.; Wo

    1991-05-01

    Evidence is presented for the charge-exchange photoproduction, in two distinct reactions, of an isovector {rho}{pi} state of mass {similar to}1775 MeV. Results of an analysis of the decay-angular distributions are also presented, from which it is concluded that {ital J}{sup {ital P}}=1{sup {minus}}, 2{sup {minus}}, or 3{sup +}.

  16. Selective glucocorticoid control of Rho kinase isoforms regulate cell-cell interactions

    PubMed Central

    Rubenstein, Nicola M.; Callahan, Joseph A.; Lo, Daniel H.; Firestone, Gary L.

    2007-01-01

    The two Rho kinase isoforms ROCK1 and ROCK2 are downstream effectors of the small GTPase RhoA, although relatively little is known about potential isoform specific functions or the selective control of their cellular activities. Using Con8 rat mammary epithelial cells, we show that the synthetic glucocorticoid dexamethasone strongly stimulates the level of ROCK2 protein, which accounts for the increase in total cellular ROCK2 activity, whereas, steroid treatment down-regulated ROCK1 specific kinase activity without altering ROCK1 protein levels. In Con8 cells, the glucocorticoid induced formation of tight junctions requires the steroid-mediated down-regulation RhoA and function of the RhoA antagonist Rnd3. Treatment with the ROCK inhibitor Y-27632 ablated both the glucocorticoid-induced and Rnd3-mediated stimulation in tight junction sealing. Taken together, our results demonstrate that the expression and activity of ROCK1 and ROCK2 can be uncoupled in a signal-dependent manner, and further implicate a new function for ROCK2 in the steroid control of tight junction dynamics. PMID:17240358

  17. Role of Rho-kinase and its inhibitors in pulmonary hypertension.

    PubMed

    Duong-Quy, Sy; Bei, Yihua; Liu, Zhongmin; Dinh-Xuan, Anh Tuan

    2013-03-01

    Pulmonary hypertension (PH) is an incurable disease with a dreadful survival rate. The disease is characterized by sustained vasoconstriction, progressive vascular remodeling, and irreversible right heart dysfunction. While hypoxic pulmonary vasoconstriction (HPV) is known to be the main pathophysiological factor causing the rise in pulmonary arterial pressure, biological mechanisms leading to HPV and vascular remodeling are multiple and complex and, as yet, incompletely understood. It is thought that molecular interactions and cross talks are involved in the pathogenesis of PH, perturbing the physiological balance between substances controlling vascular tone, cell growth and apoptosis. This balance is achieved by subtle interactions between factors acting as both vasodilators and inhibitors of cell growth like nitric oxide, prostacyclin, vasoactive intestinal peptide and molecules with potent vasoconstrictor and cell growth activities like endothelin-1. Recent in vivo studies showed that the Rho GTPase/RhoA pathway and its downstream effectors, the Rho-kinases (ROCK-1 and ROCK-2), had an important role in PH, due to its lasting effects on vasoconstriction and pulmonary cell proliferation leading to vascular remodeling. Beneficial effects obtained in vivo with Rho-kinase inhibitors (e.g.Y-27632 and fasudil) in experimental PH will hopefully lead to future clinical trials with new compounds selectively targeting this pathway, which is now proven to be detrimental when over-activated in both experimental animals and human patients. PMID:23261521

  18. RhoA and ROCK mediate histamine-induced vascular leakage and anaphylactic shock

    PubMed Central

    Mikelis, Constantinos M.; Simaan, May; Ando, Koji; Fukuhara, Shigetomo; Sakurai, Atsuko; Amornphimoltham, Panomwat; Masedunskas, Andrius; Weigert, Roberto; Chavakis, Triantafyllos; Adams, Ralf; Offermanns, Stefan; Mochizuki, Naoki; Zheng, Yi; Gutkind, J. Silvio

    2015-01-01

    Histamine-induced vascular leakage is an integral component of many highly prevalent human diseases, including allergies, asthma, and anaphylaxis. Yet, how histamine induces the disruption of the endothelial barrier is not well defined. By using genetically modified animal models, pharmacologic inhibitors, and a synthetic biology approach, here we show that the small GTPase RhoA mediates histamine-induced vascular leakage. Histamine causes the rapid formation of focal adherens junctions, disrupting the endothelial barrier by acting on H1R Gαq-coupled receptors, which is blunted in endothelial Gαq/11 KO mice. Interfering with RhoA and ROCK function abolishes endothelial permeability, while phospholipase Cβ plays a limited role. Moreover, endothelial-specific RhoA gene deletion prevents vascular leakage and passive cutaneous anaphylaxis in vivo, and ROCK inhibitors protect from lethal systemic anaphylaxis. This study supports a key role for the RhoA signaling circuitry in vascular permeability, thereby identifying novel pharmacological targets for many human diseases characterized by aberrant vascular leakage. PMID:25857352

  19. Rho0 Photoproduction in Ultra-Peripheral Relativistic Heavy Ion Collisions with STAR

    SciTech Connect

    STAR Coll

    2007-12-20

    Photoproduction reactions occur when the electromagnetic field of a relativistic heavy ion interacts with another heavy ion. The STAR collaboration presents a measurement of {rho}{sup 0} and direct {pi}{sup +}{pi}{sup -} photoproduction in ultra-peripheral relativistic heavy ion collisions at {radical}s{sub NN} = 200 GeV. We observe both exclusive photoproduction and photoproduction accompanied by mutual Coulomb excitation. We find a coherent cross-section of {sigma}(AuAu {yields} Au*Au* {rho}{sup 0}) = 530 {+-} 19 (stat.) {+-} 57 (syst.) mb, in accord with theoretical calculations based on a Glauber approach, but considerably below the predictions of a color dipole model. The {rho}{sup 0} transverse momentum spectrum (p{sub T}{sup 2}) is fit by a double exponential curve including both coherent and incoherent coupling to the target nucleus; we find {sigma}{sub inc}/{sigma}{sub coh} = 0.29 {+-} 0.03 (stat.) {+-} 0.08 (syst.). The ratio of direct {pi}{sup +}{pi}{sup -} production is comparable to that observed in {gamma}p collisions at HERA, and appears to be independent of photon energy. Finally, the measured {rho}{sup 0} spin helicity matrix elements agree within errors with the expected s-channel helicity conservation.

  20. KIF17 regulates RhoA-dependent actin remodeling at epithelial cell-cell adhesions.

    PubMed

    Acharya, Bipul R; Espenel, Cedric; Libanje, Fotine; Raingeaud, Joel; Morgan, Jessica; Jaulin, Fanny; Kreitzer, Geri

    2016-03-01

    The kinesin KIF17 localizes at microtubule plus-ends where it contributes to regulation of microtubule stabilization and epithelial polarization. We now show that KIF17 localizes at cell-cell adhesions and that KIF17 depletion inhibits accumulation of actin at the apical pole of cells grown in 3D organotypic cultures and alters the distribution of actin and E-cadherin in cells cultured in 2D on solid supports. Overexpression of full-length KIF17 constructs or truncation mutants containing the N-terminal motor domain resulted in accumulation of newly incorporated GFP-actin into junctional actin foci, cleared E-cadherin from cytoplasmic vesicles and stabilized cell-cell adhesions to challenge with calcium depletion. Expression of these KIF17 constructs also increased cellular levels of active RhoA, whereas active RhoA was diminished in KIF17-depleted cells. Inhibition of RhoA or its effector ROCK, or expression of LIMK1 kinase-dead or activated cofilin(S3A) inhibited KIF17-induced junctional actin accumulation. Interestingly, KIF17 activity toward actin depends on the motor domain but is independent of microtubule binding. Together, these data show that KIF17 can modify RhoA-GTPase signaling to influence junctional actin and the stability of the apical junctional complex of epithelial cells. PMID:26759174

  1. Rapid Remodeling of Invadosomes by Gi-coupled Receptors: DISSECTING THE ROLE OF Rho GTPases.

    PubMed

    Kedziora, Katarzyna M; Leyton-Puig, Daniela; Argenzio, Elisabetta; Boumeester, Anja J; van Butselaar, Bram; Yin, Taofei; Wu, Yi I; van Leeuwen, Frank N; Innocenti, Metello; Jalink, Kees; Moolenaar, Wouter H

    2016-02-26

    Invadosomes are actin-rich membrane protrusions that degrade the extracellular matrix to drive tumor cell invasion. Key players in invadosome formation are c-Src and Rho family GTPases. Invadosomes can reassemble into circular rosette-like superstructures, but the underlying signaling mechanisms remain obscure. Here we show that Src-induced invadosomes in human melanoma cells (A375M and MDA-MB-435) undergo rapid remodeling into dynamic extracellular matrix-degrading rosettes by distinct G protein-coupled receptor agonists, notably lysophosphatidic acid (LPA; acting through the LPA1 receptor) and endothelin. Agonist-induced rosette formation is blocked by pertussis toxin, dependent on PI3K activity and accompanied by localized production of phosphatidylinositol 3,4,5-trisphosphate, whereas MAPK and Ca(2+) signaling are dispensable. Using FRET-based biosensors, we show that LPA and endothelin transiently activate Cdc42 through Gi, concurrent with a biphasic decrease in Rac activity and differential effects on RhoA. Cdc42 activity is essential for rosette formation, whereas G12/13-mediated RhoA-ROCK signaling suppresses the remodeling process. Our results reveal a Gi-mediated Cdc42 signaling axis by which G protein-coupled receptors trigger invadosome remodeling, the degree of which is dictated by the Cdc42-RhoA activity balance. PMID:26740622

  2. Dock4 is regulated by RhoG and promotes Rac-dependent cell migration.

    PubMed

    Hiramoto,