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Sample records for acids play important

  1. Play's Importance in School

    ERIC Educational Resources Information Center

    Sandberg, Anette; Heden, Rebecca

    2011-01-01

    The purpose of this study is to contribute knowledge on and gain an understanding of elementary school teachers' perspectives on the function of play in children's learning processes. The study is qualitative with a hermeneutical approach and has George Herbert Mead as a theoretical frame of reference. Interviews have been carried out with seven…

  2. Thioesterase II of Escherichia coli Plays an Important Role in 3-Hydroxydecanoic Acid Production

    PubMed Central

    Zheng, Zhong; Gong, Qiang; Liu, Tao; Deng, Ying; Chen, Jin-Chun; Chen, Guo-Qiang

    2004-01-01

    3-Hydroxydecanoic acid (3HD) was produced in Escherichia coli by mobilizing (R)-3-hydroxydecanoyl-acyl carrier protein-coenzyme A transacylase (PhaG, encoded by the phaG gene). By employing an isogenic tesB (encoding thioesterase II)-negative knockout E. coli strain, CH01, it was found that the expressions of tesB and phaG can up-regulate each other. In addition, 3HD was synthesized from glucose or fructose by recombinant E. coli harboring phaG and tesB. This study supports the hypothesis that the physiological role of thioesterase II in E. coli is to prevent the abnormal accumulation of intracellular acyl-coenzyme A. PMID:15240249

  3. Degradation of oxalic acid by the mycoparasite Coniothyrium minitans plays an important role in interacting with Sclerotinia sclerotiorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coniothyrium minitans is a mycoparasite of the phytopathogenic fungus Sclerotinia sclerotiorum. Sclerotinia sclerotiorum produces a virulence factor oxalic acid (OA) which is toxic to plants and also to C. minitans, and C. minitans detoxifies OA by degradation. In this study, two oxalate decarboxyla...

  4. Degradation of oxalic acid by the mycoparasite Coniothyrium minitans plays an important role in interacting with Sclerotinia sclerotiorum.

    PubMed

    Zeng, Li-Mei; Zhang, Jing; Han, Yong-Chao; Yang, Long; Wu, Ming-de; Jiang, Dao-Hong; Chen, Weidong; Li, Guo-Qing

    2014-08-01

    Coniothyrium minitans (Cm) is a mycoparasite of the phytopathogenic fungus Sclerotinia sclerotiorum (Ss). Ss produces a virulence factor oxalic acid (OA) which is toxic to plants and also to Cm, and Cm detoxifies OA by degradation. In this study, two oxalate decarboxylase genes, Cmoxdc1 and Cmoxdc2, were cloned from Cm strain Chy-1. OA and low pH induced expression of Cmoxdc1, but not Cmoxdc2. Cmoxdc1 was partially responsible for OA degradation, whereas Cmoxdc2 had no effect on OA degradation. Disruption of Cmoxdc1 in Cm reduced its ability to infect Ss in dual cultures where OA accumulated. Compared with Chy-1, the Cmoxdc1-disrupted mutants had reduced expression levels of two mycoparasitism-related genes chitinase (Cmch1) and β-1,3-glucanase (Cmg1), and had no detectable activity of extracellular proteases in the presence of OA. On the other hand, the cultural filtrates of the Cmoxdc1-disrupted mutants in OA-amended media showed enhanced antifungal activity, possibly because of increased production of antifungal substances under acidic pH condition resulted from reduced Cmoxdc1-mediated OA degradation. This study provides direct genetic evidence of OA degradation regulating mycoparasitism and antibiosis of Cm against Ss, and sheds light on the sophisticated strategies of Cm in interacting with metabolically active mycelia and dormant sclerotia of Ss.

  5. The Importance of Play: Why Children Need to Play

    ERIC Educational Resources Information Center

    Bodrova, Elena; Leong, Deborah J.

    2005-01-01

    In this article, the authors discuss the important role of dramatic ("pretend") play in early childhood with increasing emphasis at school on developing academic skills in children at younger and younger ages. Play is especially beneficial to children's learning when it reaches a certain degree of sophistication. In other words, "unproductive"…

  6. DJ-1 plays an important role in caffeic acid-mediated protection of the gastrointestinal mucosa against ketoprofen-induced oxidative damage.

    PubMed

    Cheng, Yu-Ting; Ho, Cheng-Ying; Jhang, Jhih-Jia; Lu, Chi-Cheng; Yen, Gow-Chin

    2014-10-01

    Ketoprofen is widely used to alleviate pain and inflammation in clinical medicine; however, this drug may cause oxidative stress and lead to gastrointestinal (GI) ulcers. We previously reported that nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in protecting cells against reactive oxygen species, and it facilitates the prevention of ketoprofen-induced GI mucosal ulcers. Recent reports suggested that Nrf2 becomes unstable in the absence of DJ-1/PARK7, attenuating the activity of Nrf2-regulated downstream antioxidant enzymes. Thus, increasing Nrf2 translocation by DJ-1 may represent a novel means for GI protection. In vitro, caffeic acid increases the nuclear/cytosolic Nrf2 ratio and the mRNA expression of the downstream antioxidant enzymes, ϒ-glutamyl cysteine synthetase, glutathione peroxidase, glutathione reductase, and heme oxygenase-1, by activating the JNK/p38 pathway in Int-407 cells. Moreover, knockdown of DJ-1 also reversed caffeic acid-induced nuclear Nrf2 protein expression in a JNK/p38-dependent manner. Our results also indicated that treatment of Sprague-Dawley rats with caffeic acid prior to the administration of ketoprofen inhibited oxidative damage and reversed the inhibitory effects of ketoprofen on the antioxidant system and DJ-1 protein expression in the GI mucosa. Our observations suggest that DJ-1 plays an important role in caffeic acid-mediated protection against ketoprofen-induced oxidative damage in the GI mucosa.

  7. A vacuolar β-glucosidase homolog that possesses glucose-conjugated abscisic acid hydrolyzing activity plays an important role in osmotic stress responses in Arabidopsis.

    PubMed

    Xu, Zheng-Yi; Lee, Kwang Hee; Dong, Ting; Jeong, Jae Cheol; Jin, Jing Bo; Kanno, Yuri; Kim, Dae Heon; Kim, Soo Youn; Seo, Mitsunori; Bressan, Ray A; Yun, Dae-Jin; Hwang, Inhwan

    2012-05-01

    The phytohormone abscisic acid (ABA) plays a critical role in various physiological processes, including adaptation to abiotic stresses. In Arabidopsis thaliana, ABA levels are increased both through de novo biosynthesis and via β-glucosidase homolog1 (BG1)-mediated hydrolysis of Glc-conjugated ABA (ABA-GE). However, it is not known how many different β-glucosidase proteins produce ABA from ABA-GE and how the multiple ABA production pathways are coordinated to increase ABA levels. Here, we report that a previously undiscovered β-glucosidase homolog, BG2, produced ABA by hydrolyzing ABA-GE and plays a role in osmotic stress response. BG2 localized to the vacuole as a high molecular weight complex and accumulated to high levels under dehydration stress. BG2 hydrolyzed ABA-GE to ABA in vitro. In addition, BG2 increased ABA levels in protoplasts upon application of exogenous ABA-GE. Overexpression of BG2 rescued the bg1 mutant phenotype, as observed for the overexpression of NCED3 in bg1 mutants. Multiple Arabidopsis bg2 alleles with a T-DNA insertion in BG2 were more sensitive to dehydration and NaCl stress, whereas BG2 overexpression resulted in enhanced resistance to dehydration and NaCl stress. Based on these observations, we propose that, in addition to the de novo biosynthesis, ABA is produced in multiple organelles by organelle-specific β-glucosidases in response to abiotic stresses.

  8. Superoxide anions produced by inflammatory cells play an important part in the pathogenesis of acid and pepsin induced oesophagitis in rabbits.

    PubMed Central

    Naya, M J; Pereboom, D; Ortego, J; Alda, J O; Lanas, A

    1997-01-01

    BACKGROUND: Reactive oxygen metabolites have been associated with gastrointestinal injury. OBJECTIVE: To investigate whether mucosal reactive oxygen metabolites are involved in acid and pepsin induced oesophagitis, and if so, which specific metabolites. METHODS: The effects of free radical scavengers and the anti-inflammatory drug ketotifen on rabbit oesophagitis induced by acidified pepsin were studied. Isolated oesophageal cells were obtained before and after oesophageal injury and the generation of superoxide anion and hydrogen peroxide was analysed by flow cytometry. The presence of inflammatory cells was determined by indirect immunofluorescence with a mouse antirabbit CD11b antibody. RESULTS: Of the free radical scavengers tested, superoxide dismutase, which reacts with the superoxide anion, significantly reduced oesophagitis, whereas catalase, which reacts with hydrogen peroxide, had only a mild effect and dimethylsulphoxide had no effect. Ketotifen significantly reduced the inflammation and also prevented the induction of oesophagitis. Isolated cells obtained from the oesophageal mucosa after acidified pepsin exposure generated increased amounts of superoxide anions, which were mainly produced by CD11b positive cells. CONCLUSIONS: Reactive oxygen metabolites, especially superoxide anion, produced by inflammatory cells play a significant part in the genesis of oesophagitis induced by acid and pepsin in rabbits and might be a target for future medical therapy. Images PMID:9071927

  9. Niflumic acid-sensitive ion channels play an important role in the induction of glucose-stimulated insulin secretion by cyclic AMP in mice

    PubMed Central

    Fujimoto, W.; Miki, T.; Ogura, T.; Zhang, M.; Seino, Y.; Satin, L. S.; Nakaya, H.

    2015-01-01

    Aims/hypothesis We have previously reported that glucose-stimulated insulin secretion (GSIS) is induced by glucagon-like peptide-1 (GLP-1) in mice lacking ATP-sensitive K+ (KATP) channels (Kir6.2−/− mice [up-to-date symbol for Kir6.2 gene is Kcnj11]), in which glucose alone does not trigger insulin secretion. This study aimed to clarify the mechanism involved in the induction of GSIS by GLP-1. Methods Pancreas perfusion experiments were performed using wild-type (Kir6.2+/+) or Kir6.2−/− mice. Glucose concentrations were either changed abruptly from 2.8 to 16.7 mmol/l or increased stepwise (1.4 mmol/l per step) from 2.8 to 12.5 mmol/l. Electrophysiological experiments were performed using pancreatic beta cells isolated from Kir6.2−/− mice or clonal pancreatic beta cells (MIN6 cells) after pharmacologically inhibiting their KATP channels with glibenclamide. Results The combination of cyclic AMP plus 16.7 mmol/l glucose evoked insulin secretion in Kir6.2−/− pancreases where glucose alone was ineffective as a secretagogue. The secretion was blocked by the application of niflumic acid. In KATP channel-inactivated MIN6 cells, niflumic acid similarly inhibited the membrane depolarisation caused by cAMP plus glucose. Surprisingly, stepwise increases of glucose concentration triggered insulin secretion only in the presence of cAMP or GLP-1 in Kir6.2+/+, as in Kir6.2−/− pancreases. Conclusions/interpretation Niflumic acid-sensitive ion channels participate in the induction of GSIS by cyclic AMP in Kir6.2−/− beta cells. Cyclic AMP thus not only acts as a potentiator of insulin secretion, but appears to be permissive for GSIS via novel, niflumic acid-sensitive ion channels. This mechanism may be physiologically important for triggering insulin secretion when the plasma glucose concentration increases gradually rather than abruptly. PMID:19266181

  10. Alteration of a single amino acid in the basic domain of Marek's disease virus Meq oncoprotein plays an important role in T-cell transformation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Marek’s disease virus encoded oncoprotein, Meq, has been shown to play a major role in transformation of T-lymphocytes. We have earlier shown that replacement of the meq gene in the very virulent strain Md5 with that of vaccine strain CVI988/Rispens resulted in virus attenuation in chickens. To dete...

  11. Toward Parent and Teacher Understanding of the Importance of Play.

    ERIC Educational Resources Information Center

    Salvay, Betty

    This paper focuses on the importance of play for a child's physical, emotional, cognitive, and social development. Three major purposes of the report are: (1) to persuade those concerned with the education of young children that play is an essential activity for children's well-being and should be facilitated at home and in the classroom, (2) to…

  12. THE IMPORTANCE OF PLAY DURING HOSPITALIZATION OF CHILDREN

    PubMed Central

    Koukourikos, Konstantinos; Tzeha, Laila; Pantelidou, Parthenopi; Tsaloglidou, Areti

    2015-01-01

    Introduction: Play constitutes an essential parameter of the normal psychosomatic development of children, as well as their statutory right. It is also an important means of communication in childhood. Objective: To review, detect and highlight all data cited regarding the role of play during the hospitalization of children. Methodology: Literature review was achieved by searching the databases Scopus, PubMed, Cinhal in English, using the following key words: therapeutic play, play therapy, hospitalized child, therapist. Results: During hospitalization, play either in the form of therapeutic play, or as in the form of play therapy, is proven to be of high therapeutic value for ill children, thus contributing to both their physical and emotional well-being and to their recovery. It helps to investigate issues related to the child’s experiences in the hospital and reduce the intensity of negative feelings accompanying a child’s admission to hospital and hospitalization. Play is widely used in pre-operative preparation and invasive procedures, while its use among children hospitalized for cancer is beneficial. Conclusion: The use of play in hospital may become a tool in the hands of healthcare professionals, in order to provide substantial assistance to hospitalized children, as long as they have appropriate training, patience, and will to apply it during hospitalization. PMID:26889107

  13. Play.

    ERIC Educational Resources Information Center

    Rogers, Fred; Sharapan, Hedda

    1993-01-01

    Contends that, in childhood, work and play seem to come together. Says that for young children their play is their work, and the more adults encourage children to play, the more they emphasize important lifelong resource. Examines some uses of children's play, making and building, artwork, dramatic play, monsters and superheroes, gun play, and…

  14. The RNA-Binding Chaperone Hfq Is an Important Global Regulator of Gene Expression in Pasteurella multocida and Plays a Crucial Role in Production of a Number of Virulence Factors, Including Hyaluronic Acid Capsule

    PubMed Central

    Mégroz, Marianne; Kleifeld, Oded; Wright, Amy; Powell, David; Harrison, Paul; Adler, Ben; Harper, Marina

    2016-01-01

    The Gram-negative bacterium Pasteurella multocida is the causative agent of a number of economically important animal diseases, including avian fowl cholera. Numerous P. multocida virulence factors have been identified, including capsule, lipopolysaccharide (LPS), and filamentous hemagglutinin, but little is known about how the expression of these virulence factors is regulated. Hfq is an RNA-binding protein that facilitates riboregulation via interaction with small noncoding RNA (sRNA) molecules and their mRNA targets. Here, we show that a P. multocida hfq mutant produces significantly less hyaluronic acid capsule during all growth phases and displays reduced in vivo fitness. Transcriptional and proteomic analyses of the hfq mutant during mid-exponential-phase growth revealed altered transcript levels for 128 genes and altered protein levels for 78 proteins. Further proteomic analyses of the hfq mutant during the early exponential growth phase identified 106 proteins that were produced at altered levels. Both the transcript and protein levels for genes/proteins involved in capsule biosynthesis were reduced in the hfq mutant, as were the levels of the filamentous hemagglutinin protein PfhB2 and its secretion partner LspB2. In contrast, there were increased expression levels of three LPS biosynthesis genes, encoding proteins involved in phosphocholine and phosphoethanolamine addition to LPS, suggesting that these genes are negatively regulated by Hfq-dependent mechanisms. Taken together, these data provide the first evidence that Hfq plays a crucial role in regulating the global expression of P. multocida genes, including the regulation of key P. multocida virulence factors, capsule, LPS, and filamentous hemagglutinin. PMID:26883595

  15. Binning of shallowly sampled metagenomic sequence fragments reveals that low abundance bacteria play important roles in sulfur cycling and degradation of complex organic polymers in an acid mine drainage community

    NASA Astrophysics Data System (ADS)

    Dick, G. J.; Andersson, A.; Banfield, J. F.

    2007-12-01

    not expected to reflect the tetranucleotide frequency signature of the host genome. Four unknown tetranucleotide frequency clusters with significant sequence (6 Mb total) were noted and analyzed further. Based on phylogenetic markers and BLAST results, these clusters represent low abundance bacteria including Acintobacteria, Firmicutes, and Proteobacteria. Functional analysis of these clusters revealved that the low- abundance bacteria harbor genes that could potentially encode important ecosystem functions such as sulfur utilization (e.g. polysulfide reductase) and polymer degradation (e.g. chitinase and glycoside hydrolase). We conclude that ESOM clustering of tetranucleotide frequency patterns is an effective method for rapidly binning shotgun community genomic sequences and a valuable tool for analyzing minor community members, which despite their low abundance may play crucial ecological roles.

  16. Play: An Important Component of Preventative Behavior Management.

    ERIC Educational Resources Information Center

    Patrick, Teri

    This paper discusses linkages between play, healthy social and emotional development, and behavior management in young children. Play is defined as pleasurable, self-motivated, non-goal-directed, and spontaneous behavior, free from adult-imposed rules. Many children have limited time available for play because they are directed by adults in day…

  17. Copy number variation plays an important role in clinical epilepsy

    PubMed Central

    Olson, Heather; Shen, Yiping; Avallone, Jennifer; Sheidley, Beth R.; Pinsky, Rebecca; Bergin, Ann M.; Berry, Gerard T.; Duffy, Frank H.; Eksioglu, Yaman; Harris, David J.; Hisama, Fuki M.; Ho, Eugenia; Irons, Mira; Jacobsen, Christina M.; James, Philip; Kothare, Sanjeev; Khwaja, Omar; Lipton, Jonathan; Loddenkemper, Tobias; Markowitz, Jennifer; Maski, Kiran; Megerian, J. Thomas; Neilan, Edward; Raffalli, Peter C.; Robbins, Michael; Roberts, Amy; Roe, Eugene; Rollins, Caitlin; Sahin, Mustafa; Sarco, Dean; Schonwald, Alison; Smith, Sharon E.; Soul, Janet; Stoler, Joan M.; Takeoka, Masanori; Tan, Wen-Han; Torres, Alcy R.; Tsai, Peter; Urion, David K.; Weissman, Laura; Wolff, Robert; Wu, Bai-Lin; Miller, David T.; Poduri, Annapurna

    2015-01-01

    Objective To evaluate the role of copy number abnormalities detectable by chromosomal microarray (CMA) testing in patients with epilepsy at a tertiary care center. Methods We identified patients with ICD-9 codes for epilepsy or seizures and clinical CMA testing performed between October 2006 and February 2011 at Boston Children’s Hospital. We reviewed medical records and included patients meeting criteria for epilepsy. We phenotypically characterized patients with epilepsy-associated abnormalities on CMA. Results Of 973 patients who had CMA and ICD-9 codes for epilepsy or seizures, 805 patients satisfied criteria for epilepsy. We observed 437 copy number variants (CNVs) in 323 patients (1–4 per patient), including 185 (42%) deletions and 252 (58%) duplications. Forty (9%) were confirmed de novo, 186 (43%) were inherited, and parental data were unavailable for 211 (48%). Excluding full chromosome trisomies, CNV size ranged from 18 kb to 142 Mb, and 34% were over 500 kb. In at least 40 cases (5%), the epilepsy phenotype was explained by a CNV, including 29 patients with epilepsy-associated syndromes and 11 with likely disease-associated CNVs involving epilepsy genes or “hotspots.” We observed numerous recurrent CNVs including 10 involving loss or gain of Xp22.31, a region described in patients with and without epilepsy. Interpretation Copy number abnormalities play an important role in patients with epilepsy. Given that the diagnostic yield of CMA for epilepsy patients is similar to the yield in autism spectrum disorders and in prenatal diagnosis, for which published guidelines recommend testing with CMA, we recommend the implementation of CMA in the evaluation of unexplained epilepsy. PMID:24811917

  18. Parent participation plays an important part in promoting physical activity

    PubMed Central

    Lindqvist, Anna-Karin; Kostenius, Catrine; Gard, Gunvor; Rutberg, Stina

    2015-01-01

    Although physical activity (PA) is an important and modifiable determinant of health, in Sweden only 15% of boys and 10% of girls aged 15 years old achieve the recommended levels of PA 7 days per week. Adolescents’ PA levels are associated with social influence exerted by parents, friends, and teachers. The purpose of this study was to describe parents’ experiences of being a part of their adolescents’ empowerment-inspired PA intervention. A qualitative interview study was performed at a school in the northern part of Sweden. A total of 10 parents were interviewed, and the collected data were analyzed with qualitative content analysis. Three subthemes were combined into one main theme, demonstrating that parents are one important part of a successful PA intervention. The life of an adolescent has many options and demands that make it difficult to prioritize PA. Although parents felt that they were important in supporting their adolescent, a successful PA intervention must have multiple components. Moreover, the parents noted that the intervention had a positive effect upon not only their adolescents’, but also their own PA. Interventions aimed at promoting PA among adolescents should include measures to stimulate parent participation, have an empowerment approach, and preferably be school-based. PMID:26282870

  19. Parent participation plays an important part in promoting physical activity.

    PubMed

    Lindqvist, Anna-Karin; Kostenius, Catrine; Gard, Gunvor; Rutberg, Stina

    2015-01-01

    Although physical activity (PA) is an important and modifiable determinant of health, in Sweden only 15% of boys and 10% of girls aged 15 years old achieve the recommended levels of PA 7 days per week. Adolescents' PA levels are associated with social influence exerted by parents, friends, and teachers. The purpose of this study was to describe parents' experiences of being a part of their adolescents' empowerment-inspired PA intervention. A qualitative interview study was performed at a school in the northern part of Sweden. A total of 10 parents were interviewed, and the collected data were analyzed with qualitative content analysis. Three subthemes were combined into one main theme, demonstrating that parents are one important part of a successful PA intervention. The life of an adolescent has many options and demands that make it difficult to prioritize PA. Although parents felt that they were important in supporting their adolescent, a successful PA intervention must have multiple components. Moreover, the parents noted that the intervention had a positive effect upon not only their adolescents', but also their own PA. Interventions aimed at promoting PA among adolescents should include measures to stimulate parent participation, have an empowerment approach, and preferably be school-based.

  20. Vegetation plays an important role in mediating future water resources

    NASA Astrophysics Data System (ADS)

    Ukkola, A. M.; Keenan, T. F.; Kelley, D. I.; Prentice, I. C.

    2016-09-01

    Future environmental change is expected to modify the global hydrological cycle, with consequences for the regional distribution of freshwater supplies. Regional precipitation projections, however, differ largely between models, making future water resource projections highly uncertain. Using two representative concentration pathways and nine climate models, we estimate 21st century water resources across Australia, employing both a process-based dynamic vegetation model and a simple hydrological framework commonly used in water resource studies to separate the effects of climate and vegetation on water resources. We show surprisingly robust, pathway-independent regional patterns of change in water resources despite large uncertainties in precipitation projections. Increasing plant water use efficiency (due to the changing atmospheric CO2) and reduced green vegetation cover (due to the changing climate) relieve pressure on water resources for the highly populated, humid coastal regions of eastern Australia. By contrast, in semi-arid regions across Australia, runoff declines are amplified by CO2-induced greening, which leads to increased vegetation water use. These findings highlight the importance of including vegetation dynamics in future water resource projections.

  1. Rapid nuclear import of short nucleic acids.

    PubMed

    Kitagawa, Mai; Okamoto, Akimitsu

    2016-10-01

    Exogenous short-chain nucleic acids undergo rapid import into the nucleus. Fluorescence-labeled dT1-13 DNA microinjected into the cytoplasm domain of a HeLa cell was rapidly imported into the nucleus domain within 1min. This is much more rapid than what has been observed for intracellular diffusion of small molecules. In contrast, import of longer nucleic acids with a length of over 30nt into the nucleus was suppressed.

  2. Identification of quantitative trait loci(QTL) controlling important fatty acids in peanut (Arachis hypogaea L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fatty acids play important role in controlling oil quality of peanut. In addition to the major fatty acids, oleic acid (C18:1) and linoleic acid (C18:2) accounting for about 80%, there are several minor fatty acids accounting for about 20% in peanut oil, such as palmitic acid (PA, C16:0), stearic (S...

  3. Importance of lactic acid bacteria in Asian fermented foods

    PubMed Central

    2011-01-01

    Lactic acid bacteria play important roles in various fermented foods in Asia. Besides being the main component in kimchi and other fermented foods, they are used to preserve edible food materials through fermentation of other raw-materials such as rice wine/beer, rice cakes, and fish by producing organic acids to control putrefactive microorganisms and pathogens. These bacteria also provide a selective environment favoring fermentative microorganisms and produce desirable flavors in various fermented foods. This paper discusses the role of lactic acid bacteria in various non-dairy fermented food products in Asia and their nutritional and physiological functions in the Asian diet. PMID:21995342

  4. The importance of play in adulthood. An interview with Joan M. Erikson. Interview by Daniel Benveniste.

    PubMed

    Erikson, J M

    1998-01-01

    Joan M. Erikson (1902-1997) was an artist, a writer, a mother, and the wife and collaborator of Erik H. Erikson (1902-1994), one of the most important and influential psychoanalysts in the world. The following is an edited dialogue on one of her favorite topics--The Importance of Play in Adulthood. It features her thoughts on the subject and reminiscences of the ways she played throughout her life. She muses on play in relation to humor, fun, the role of the fool, and more. The article was a project undertaken in the spirit of play and it will hopefully evoke further playful musings in the minds of readers.

  5. Play

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    Designing a game with a serious purpose involves considering the worlds of Reality and Meaning yet it is undeniably impossible to create a game without a third world, one that is specifically concerned with what makes a game a game: the play elements. This third world, the world of people like designers and artists, and disciplines as computer science and game design, I call the world of Play and this level is devoted to it. The level starts off with some of the misperceptions people have of play. Unlike some may think, we play all the time, even when we grow old—this was also very noticeable in designing the game Levee Patroller as the team exhibited very playful behavior at many occasions. From there, I go into the aspects that characterize this world. The first concerns the goal of the game. This relates to the objectives people have to achieve within the game. This is constituted by the second aspect: the gameplay. Taking actions and facing challenges is subsequently constituted by a gameworld, which concerns the third aspect. And all of it is not possible without the fourth and final aspect, the type of technology that creates and facilitates the game. The four aspects together make up a “game concept” and from this world such a concept can be judged on the basis of three closely interrelated criteria: engagement, immersion, and fun.

  6. The Importance of Free Play in the Early Childhood Classroom: Perspectives from a Teacher

    ERIC Educational Resources Information Center

    Engel, Maria

    2015-01-01

    Teaching is hard. It's the most rewarding, fulfilling job in the world, but it's also frustrating, infuriating, and really, really hard. In this article, the author reflects on the importance of free play in early childhood classrooms. If teachers want to create happy children who love learning, forcing them to sit at desks or tables through early…

  7. Homeodomain-interacting protein kinase 2 plays an important role in normal terminal erythroid differentiation.

    PubMed

    Hattangadi, Shilpa M; Burke, Karly A; Lodish, Harvey F

    2010-06-10

    Gene-targeting experiments report that the homeodomain-interacting protein kinases 1 and 2, Hipk1 and Hipk2, are essential but redundant in hematopoietic development because Hipk1/Hipk2 double-deficient animals exhibit severe defects in hematopoiesis and vasculogenesis, whereas the single knockouts do not. These serine-threonine kinases phosphorylate and consequently modify the functions of several important hematopoietic transcription factors and cofactors. Here we show that Hipk2 knockdown alone plays a significant role in terminal fetal liver erythroid differentiation. Hipk1 and Hipk2 are highly induced during primary mouse fetal liver erythropoiesis. Specific knockdown of Hipk2 inhibits terminal erythroid cell proliferation (explained in part by impaired cell-cycle progression as well as increased apoptosis) and terminal enucleation as well as the accumulation of hemoglobin. Hipk2 knockdown also reduces the transcription of many genes involved in proliferation and apoptosis as well as important, erythroid-specific genes involved in hemoglobin biosynthesis, such as alpha-globin and mitoferrin 1, demonstrating that Hipk2 plays an important role in some but not all aspects of normal terminal erythroid differentiation.

  8. Abscisic acid uridine diphosphate glucosyltransferases play a crucial role in abscisic acid homeostasis in Arabidopsis.

    PubMed

    Dong, Ting; Xu, Zheng-Yi; Park, Youngmin; Kim, Dae Heon; Lee, Yongjik; Hwang, Inhwan

    2014-05-01

    The phytohormone abscisic acid (ABA) is crucial for plant growth and adaptive responses to various stress conditions. Plants continuously adjust the ABA level to meet physiological needs, but how ABA homeostasis occurs is not fully understood. This study provides evidence that UGT71B6, an ABA uridine diphosphate glucosyltransferase (UGT), and its two closely related homologs, UGT71B7 and UGT71B8, play crucial roles in ABA homeostasis and in adaptation to dehydration, osmotic stress, and high-salinity stresses in Arabidopsis (Arabidopsis thaliana). UGT RNA interference plants that had low levels of these three UGT transcripts displayed hypersensitivity to exogenous ABA and high-salt conditions during germination and exhibited a defect in plant growth. However, the ectopic expression of UGT71B6 in the atbg1 (for β-glucosidase) mutant background aggravated the ABA-deficient phenotype of atbg1 mutant plants. In addition, modulation of the expression of the three UGTs affects the expression of CYP707A1 to CYP707A4, which encode ABA 8'-hydroxylases; four CYP707As were expressed at higher levels in the UGT RNA interference plants but at lower levels in the UGT71B6:GFP-overexpressing plants. Based on these data, this study proposes that UGT71B6 and its two homologs play a critical role in ABA homeostasis by converting active ABA to an inactive form (abscisic acid-glucose ester) depending on intrinsic cellular and environmental conditions in plants.

  9. Mitochondria play an important role in the cell proliferation suppressing activity of berberine

    PubMed Central

    Yan, Xiao-Jin; Yu, Xuan; Wang, Xin-Pei; Jiang, Jing-Fei; Yuan, Zhi-Yi; Lu, Xi; Lei, Fan; Xing, Dong-Ming

    2017-01-01

    After being studied for approximately a century, berberine (BBR) has been found to act on various targets and pathways. A great challenge in the pharmacological analysis of BBR at present is to identify which target(s) plays a decisive role. In the study described herein, a rescue experiment was designed to show the important role of mitochondria in BBR activity. A toxic dose of BBR was applied to inhibit cell proliferation and mitochondrial activity, then α-ketobutyrate (AKB), an analogue of pyruvate that serves only as an electron receptor of NADH, was proven to partially restore cell proliferation. However, mitochondrial morphology damage and TCA cycle suppression were not recovered by AKB. As the AKB just help to regenerate NAD+, which is make up for part function of mitochondrial, the recovered cell proliferation stands for the contribution of mitochondria to the activity of BBR. Our results also indicate that BBR suppresses tumour growth and reduces energy charge and mitochondrial DNA (mtDNA) copy number in a HepG2 xenograft model. In summary, our study suggests that mitochondria play an important role in BBR activity regarding tumour cell proliferation and metabolism. PMID:28181523

  10. LKR/SDH Plays Important Roles throughout the Tick Life Cycle Including a Long Starvation Period

    PubMed Central

    Battur, Banzragch; Boldbaatar, Damdinsuren; Umemiya-Shirafuji, Rika; Liao, Min; Battsetseg, Badgar; Taylor, DeMar; Baymbaa, Badarch; Fujisaki, Kozo

    2009-01-01

    Background Lysine-ketoglutarate reductase/saccharopine dehydrogenase (LKR/SDH) is a bifunctional enzyme catalyzing the first two steps of lysine catabolism in plants and mammals. However, to date, the properties of the lysine degradation pathway and biological functions of LKR/SDH have been very little described in arthropods such as ticks. Methodology/Principal Findings We isolated and characterized the gene encoding lysine-ketoglutarate reductase (LKR, EC 1.5.1.8) and saccharopine dehydrogenase (SDH, EC 1.5.1.9) from a tick, Haemaphysalis longicornis, cDNA library that encodes a bifunctional polypeptide bearing domains similar to the plant and mammalian LKR/SDH enzymes. Expression of LKR/SDH was detected in all developmental stages, indicating an important role throughout the tick life cycle, including a long period of starvation after detachment from the host. The LKR/SDH mRNA transcripts were more abundant in unfed and starved ticks than in fed and engorged ticks, suggesting that tick LKR/SDH are important for the starved tick. Gene silencing of LKR/SDH by RNAi indicated that the tick LKR/SDH plays an integral role in the osmotic regulation of water balance and development of eggs in ovary of engorged females. Conclusions/Significance Transcription analysis and gene silencing of LKR/SDH indicated that tick LKR/SDH enzyme plays not only important roles in egg production, reproduction and development of the tick, but also in carbon, nitrogen and water balance, crucial physiological processes for the survival of ticks. This is the first report on the role of LKR/SDH in osmotic regulation in animals including vertebrate and arthropods. PMID:19774086

  11. The Play-Literacy Nexus and the Importance of Evidence-Based Techniques in the Classroom

    ERIC Educational Resources Information Center

    Roskos, Kathleen; Christie, James

    2011-01-01

    A growing body of research has focused on the role of play in young children's literacy development and early-literacy learning. In reviewing this research, the authors define the play-literacy nexus as that space where play, language, and emerging literacy behaviors converge and interact. They describe findings about the play-literacy nexus…

  12. NHE8 plays an important role in mucosal protection via its effect on bacterial adhesion

    PubMed Central

    Liu, Chang; Xu, Hua; Zhang, Bo; Johansson, Malin E. V.; Li, Jing; Hansson, Gunnar C.

    2013-01-01

    The Na+/H+ exchanger NHE8 is expressed on the apical membrane of intestinal epithelial cells and is particularly abundant in the colon. Our previous study showed that Muc2 expression was significantly reduced in NHE8-knockout (NHE8−/−) mice, suggesting that NHE8 plays a role in mucosal protection in the colon. The current study confirms and extends our studies on the role of NHE8 in mucosal protection. The number of bacteria attached on the distal colon was significantly increased in NHE8−/− mice compared with their wild-type littermates. As expected, IL-4 expression was markedly increased in NHE8−/− mice compared with wild-type mice. Immunohistochemistry showed disorganization in the mucin layer of NHE8−/− mice, suggesting a possible direct bacteria-epithelia interaction. Furthermore, NHE8−/− mice were susceptible to dextran sodium sulfate-induced mucosal injury. In wild-type mice, dextran sodium sulfate treatment inhibited colonic NHE8 expression. In Caco-2 cells, the absence of NHE8 expression resulted in higher adhesion rates of Salmonella typhimurium but not Lactobacillus plantarum. Similarly, in vivo, S. typhimurium adhesion rate was increased in NHE8−/− mice compared with wild-type mice. Our study suggests that NHE8 plays important roles in protecting intestinal epithelia from infectious bacterial adherence. PMID:23657568

  13. Sebox plays an important role during the early mouse oogenesis in vitro.

    PubMed

    Moreno, Dafne Linda; Salazar, Zayil; Betancourt, Miguel; Casas, Eduardo; Ducolomb, Yvonne; González, Cristina; Bonilla, Edmundo

    2014-02-01

    Oogenesis is a highly complex process that requires the exquisite temporal and spatial regulation of gene expression at multiple levels. Skin-embryo-brain-oocyte homeobox (Sebox) gene encodes a transcription factor that is highly expressed in germinal vesicle stage oocytes and that plays an essential role in early embryogenesis at the 2-cell stage in the mouse. As Sebox is also expressed in mouse fetal ovaries, the aim of the present study was to study its role during the early oogenesis in vitro. Expression of Sebox was low in 15.5 to 17.5 days post coitum (dpc) ovaries, showed a peak at 18.5 dpc and then its expression decreased dramatically in newborn ovaries. Sebox expression was efficiently knocked down (>80%) in fetal mouse ovary explants in culture using RNAi technology. When fetal ovary explants were transfected with Sebox-specific RNAi, the number of oocytes at germinal vesicle stage and showing a diameter of 40-70 μm was decreased significantly to 75% after 7 days of culture relative to the negative control, and to 22.4% after 10 days of culture, thus indicating that Sebox plays an important role in the early oogenesis in mice.

  14. Thrombin Maybe Plays an Important Role in MK Differentiation into Platelets

    PubMed Central

    Yang, Xiao-Lei; Ge, Meng-Kai; Mao, De-Kui; Lv, Ying-Tao; Sun, Shu-Yan; Yu, Ai-Ping

    2016-01-01

    Objectives. After development and differentiation, megakaryocytes (MKs) can produce platelets. As is well known, thrombopoietin (TPO) can induce MKs to differentiate. The effect of thrombin on MKs differentiation is not clear. In this study, we used a human megakaryoblastic leukemia cell line (Meg-01) to assess the effect of thrombin on MKs differentiation. Methods. In order to interrogate the role of thrombin in Meg-01 cells differentiation, the changes of morphology, cellular function, and expression of diverse factors were analyzed. Results. The results show that thrombin suppresses Meg-01 cells proliferation and induces apoptosis and cell cycle arrest. Thrombin upregulates the expression of CD41b, which is one of the most important MK markers. Globin transcription factor 1 (GATA-1), an important transcriptional regulator, controls MK development and maturation. The expression of GATA-1 is also upregulated by thrombin in Meg-01 cells. The expression of B-cell lymphoma 2 (Bcl-2), an apoptosis-inhibitory protein, is downregulated by thrombin. Phosphorylated protein kinase B (p-AKT) and phosphorylated extracellular signal-regulated kinase (p-ERK) were upregulated by thrombin in Meg-01 cells. All the results are consistent with Meg-01 cells treated with TPO. Discussion and Conclusion. In conclusion, all these data indicate that thrombin maybe plays an important role in MK differentiation into platelets. However, whether the platelet-like particles are certainly platelets remains unknown. PMID:27064425

  15. [Does the diuretic effect of calcium inhibitors play an important role in the hypertensive efficacy?].

    PubMed

    Maldonado Martin, A; Gil Extremera, B; Rubio Luengo, M A

    1995-04-08

    Calcium ions play an important role in the pathophysiology of hypertension. Calcium antagonists, a group of first line drugs in the treatment of hypertension, reduce the intracellular content of calcium in vascular smooth muscle cells, and decrease the peripheral vascular resistance and blood pressure. These drugs differ from other vasodilators in that they also have natriuretic effects; thus they can affect the kidney on three levels: Renal haemodynamics are affected by increased renal blood flow, and increased glomerular filtration rate. Changes in the renin-angiotensin system can decrease aldosterone secretion. Finally, they affect sodium management by acting directly on the renal tubule, increasing sodium excretion and inhibiting tubular reabsorption of this ion. The natriuretic effect of calcium antagonists is independent of the subject's sodium balance. The vasodilating action of these drugs is therefore accompanied by a natriuretic effect that makes satisfactory control of hypertension possible without placing the patient on a low-salt or salt-free diet.

  16. Surface proteins of Staphylococcus aureus play an important role in experimental skin infection.

    PubMed

    Kwiecinski, Jakub; Jin, Tao; Josefsson, Elisabet

    2014-12-01

    Staphylococcus aureus is the most common cause of skin infections that range from mild diseases up to life-threatening conditions. Mechanisms of S. aureus virulence in those infections remain poorly studied. To investigate the impact of S. aureus surface proteins on skin infection, we used mouse models of skin abscess formation and skin necrosis, induced by a subcutaneous injection of bacteria. In the skin abscess model, a sortase-deficient S. aureus strain lacking all of its cell-wall anchored proteins was less virulent than its wild-type strain. Also, strains specifically lacking protein A, fibronecting binding proteins, clumping factor A or surface protein SasF were impaired in their virulence. When a model of dermonecrosis was studied, the S. aureus surface proteins could not be shown to be involved. In summary, surface proteins play an important role in virulence of S. aureus skin abscess infections, but not in formation of skin necrosis.

  17. Interconversion of biologically important carboxylic acids by radiation

    NASA Technical Reports Server (NTRS)

    Negron-Mendoza, A.; Ponnamperuma, C.

    1978-01-01

    The interconversion of a group of biologically important polycarboxylic acids (acetic, fumaric, malic, malonic, succinic, citric, isocitric, tricarballylic) under gamma-ray or ultraviolet radiation was investigated. The formation of high molecular weight compounds was observed in all cases. Succinic acid was formed in almost all radiolysis experiments. Citric, malonic, and succinic acids appeared to be relatively insensitive to radiation. Interconversion of the polycarboxylic acids studied may have occurred under the effect of radiation in the prebiotic earth.

  18. TGF-β signaling plays an important role in resisting γ-irradiation

    SciTech Connect

    An, You Sun; Kim, Mi-Ra; Lee, Seung-Sook; Lee, Yun-Sil; Chung, Eunkyung; Song, Jie-Young; Lee, Jeeyong; Yi, Jae Youn

    2013-02-15

    Transforming growth factor-β1 (TGF-β1) regulates various biological processes, including differentiation, bone remodeling and angiogenesis, and is particularly important as a regulator of homeostasis and cell growth in normal tissue. Interestingly, some studies have reported that TGF-β1 induces apoptosis through induction of specific genes, whereas others suggest that TGF-β1 inhibits apoptosis and facilitates cell survival. Resolving these discrepancies, which may reflect differences in cellular context, is an important research priority. Here, using the parental mink lung epithelial cell line, Mv1Lu, and its derivatives, R1B and DR26, lacking TGF-β receptors, we investigated the involvement of TGF-β signaling in the effects of γ-irradiation. We found that canonical TGF-β signaling played an important role in protecting cells from γ-irradiation. Introduction of functional TGF-β receptors or constitutively active Smads into R1B and DR26 cell lines reduced DNA fragmentation, Caspase-3 cleavage and γ-H2AX foci formation in γ-irradiated cells. Notably, we also found that de novo protein synthesis was required for the radio-resistant effects of TGF-β1. Our data thus indicate that TGF-β1 protected against γ-irradiation, decreasing DNA damage and reducing apoptosis, and thereby enhanced cell survival. - Highlights: ► TGF-β1 pretreatment inhibits γ-irradiation-induced apoptosis. ► TGF-β signaling reduces γ-irradiation-induced γ-H2AX foci formation. ► de novo protein synthesis is necessary for TGF-β1-induced radio-resistance.

  19. Rice WRKY45 plays important roles in fungal and bacterial disease resistance.

    PubMed

    Shimono, Masaki; Koga, Hironori; Akagi, Aya; Hayashi, Nagao; Goto, Shingo; Sawada, Miyuki; Kurihara, Takayuki; Matsushita, Akane; Sugano, Shoji; Jiang, Chang-Jie; Kaku, Hisatoshi; Inoue, Haruhiko; Takatsuji, Hiroshi

    2012-01-01

    Plant 'activators', such as benzothiadiazole (BTH), protect plants from various diseases by priming the plant salicylic acid (SA) signalling pathway. We have reported previously that a transcription factor identified in rice, WRKY45 (OsWRKY45), plays a pivotal role in BTH-induced disease resistance by mediating SA signalling. Here, we report further functional characterization of WRKY45. Different plant activators vary in their action points, either downstream (BTH and tiadinil) or upstream (probenazole) of SA. Rice resistance to Magnaporthe grisea, induced by both types of plant activator, was markedly reduced in WRKY45-knockdown (WRKY45-kd) rice, indicating a universal role for WRKY45 in chemical-induced resistance. Fungal invasion into rice cells was blocked at most attempted invasion sites (pre-invasive defence) in WRKY45-overexpressing (WRKY45-ox) rice. Hydrogen peroxide accumulated within the cell wall underneath invading fungus appressoria or between the cell wall and the cytoplasm, implying a possible role for H(2)O(2) in pre-invasive defence. Moreover, a hypersensitive reaction-like reaction was observed in rice cells, in which fungal growth was inhibited after invasion (post-invasive defence). The two levels of defence mechanism appear to correspond to Type I and II nonhost resistances. The leaf blast resistance of WRKY45-ox rice plants was much higher than that of other known blast-resistant varieties. WRKY45-ox plants also showed strong panicle blast resistance. BTH-induced resistance to Xanthomonas oryzae pv. oryzae was compromised in WRKY45-kd rice, whereas WRKY45-ox plants were highly resistant to this pathogen. However, WRKY45-ox plants were susceptible to Rhizoctonia solani. These results indicate the versatility and limitations of the application of this gene.

  20. Bmi1 plays an important role in dentin and mandible homeostasis by maintaining redox balance

    PubMed Central

    Yin, Ying; Xue, Xian; Wang, Qian; Chen, Ning; Miao, Dengshun

    2016-01-01

    To explore whether polycomb repressor Bmi1 plays an important role in dentin and mandible development homeostasis by maintaining redox balance, 3-week-old Bmi1 gene knockout (Bmi1-/-) mice were treated with the antioxidant N-acetylcysteine (NAC) for 2 weeks in their drinking water and phenotypes of the tooth and mandibles were compared with vehicle-treated Bmi1-/- mice and wild-type mice by radiograph, histochemistry and immunohistochemistry. Alterations of oxidative stress, DNA damage, cell proliferation and cell cycle-related parameters were also examined in mandibles. Results showed that the tooth volume and the dentin sialoprotein immunopositive areas, the cortical thickness, alveolar bone volume, osteoblast number and activity, and mRNA expression levels of Runx2, alkaline phosphatase and type I collagen were all reduced significantly in Bmi1-/- mice compared with their wild-type littermates, whereas these parameters were increased significantly in NAC-treated Bmi1-/- mice compared with vehicle-Bmi1-/- mice, although they were not normalized. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were reduced, DNA damage markers including γ-H2AX and 8-oxoguanine levels were increased, the number of Ki67 positive cells was decreased, whereas protein expression levels of p16, p19, p21, p27 and p53 were up-regulated in mandibles from Bmi1-/- mice compared with those from wild-type mice; alterations of these antioxidative enzyme activities, DNA damage markers, cell proliferation and cell cycle-related parameters were all partially rescued by the treatment with antioxidant NAC in Bmi1 deficient mice. These results demonstrated that Bmi1 deficiency resulted in defects in dentin and alveolar bone formation, while the treatment with antioxidant could improve these defects obviously. Therefore, our results indicate that Bmi1 plays an important role in stimulating dentin formation and alveolar bone formation by maintaining redox homeostasis

  1. Soil surface acidity plays a determining role in the atmospheric-terrestrial exchange of nitrous acid

    PubMed Central

    Donaldson, Melissa A.; Bish, David L.; Raff, Jonathan D.

    2014-01-01

    Nitrous acid (HONO) is an important hydroxyl (OH) radical source that is formed on both ground and aerosol surfaces in the well-mixed boundary layer. Recent studies report the release of HONO from nonacidic soils, although it is unclear how soil that is more basic than the pKa of HONO (∼3) is capable of protonating soil nitrite to serve as an atmospheric HONO source. Here, we used a coated-wall flow tube and chemical ionization mass spectrometry (CIMS) to study the pH dependence of HONO uptake onto agricultural soil and model substrates under atmospherically relevant conditions (1 atm and 30% relative humidity). Experiments measuring the evolution of HONO from pH-adjusted surfaces treated with nitrite and potentiometric titrations of the substrates show, to our knowledge for the first time, that surface acidity rather than bulk aqueous pH determines HONO uptake and desorption efficiency on soil, in a process controlled by amphoteric aluminum and iron (hydr)oxides present. The results have important implications for predicting when soil nitrite, whether microbially derived or atmospherically deposited, will act as a net source or sink of atmospheric HONO. This process represents an unrecognized mechanism of HONO release from soil that will contribute to HONO emissions throughout the day. PMID:25512517

  2. Soil surface acidity plays a determining role in the atmospheric-terrestrial exchange of nitrous acid.

    PubMed

    Donaldson, Melissa A; Bish, David L; Raff, Jonathan D

    2014-12-30

    Nitrous acid (HONO) is an important hydroxyl (OH) radical source that is formed on both ground and aerosol surfaces in the well-mixed boundary layer. Recent studies report the release of HONO from nonacidic soils, although it is unclear how soil that is more basic than the pKa of HONO (∼ 3) is capable of protonating soil nitrite to serve as an atmospheric HONO source. Here, we used a coated-wall flow tube and chemical ionization mass spectrometry (CIMS) to study the pH dependence of HONO uptake onto agricultural soil and model substrates under atmospherically relevant conditions (1 atm and 30% relative humidity). Experiments measuring the evolution of HONO from pH-adjusted surfaces treated with nitrite and potentiometric titrations of the substrates show, to our knowledge for the first time, that surface acidity rather than bulk aqueous pH determines HONO uptake and desorption efficiency on soil, in a process controlled by amphoteric aluminum and iron (hydr)oxides present. The results have important implications for predicting when soil nitrite, whether microbially derived or atmospherically deposited, will act as a net source or sink of atmospheric HONO. This process represents an unrecognized mechanism of HONO release from soil that will contribute to HONO emissions throughout the day.

  3. Biotransformation effect of Bombyx Mori L. may play an important role in treating diabetic nephropathy.

    PubMed

    Zhang, Lei; Zhang, La; Li, Yin; Guo, Xin-Feng; Liu, Xu-Sheng

    2016-11-01

    Compared with herbal drugs, medicine processed from animals (animal medicine) was thought to have more bioactive substances and higher activities. Biotransformation effect often plays an important role in their effect. However, researches about effect of animal medicine on diabetic nephropathy and applying animal medicine as natural bio-transformer were seldom reported. The purpose of this paper was to reveal the use of Bombyx Mori L. on diabetic nephropathy from ancient to modern times. The classical literature indicated that Saosi Decoction (), which contains Bombyx Mori L. or silkworm cocoon, was applied to treat disorders congruent with modern disease diabetic nephropathy from the Ming to Qing Dynasty in ancient China. Modern studies showed that Bombyx Mori L. contains four main active constituents. Among these, 1-deoxynojirimycin (1-DNJ) and quercetin showed promising potential to be new agents in diabetic nephropathy treatment. The concentrations of 1-DNJ and the activities of quercetin in Bombyx Mori L. are higher than in mulberry leaves, because of the biotransformation in the Bombyx Mori L. body. However, these specifific components need further human and mechanistic studies to determine their therapeutic potential for this challenging condition.

  4. Heterocystous Cyanobacteria in Microbialites Play an Important Role in N2 Fixation and Carbonate Mineral Precipitation

    NASA Astrophysics Data System (ADS)

    Alcantara-Hernandez, R. J.

    2015-12-01

    Lake Alchichica is a maars type crater-lake located in Central Mexico (pH > 8.9, EC ~13.39 mS cm-1). This limnological system harbors two types of microbialites that can be found around the entire perimeter of the lake (Fig. 1). These structures are representative examples of complex and diverse microbiological assemblages, where microbial activity promotes lithification by trapping, binding and/or precipitating detrital or chemical sediments. Previous studies determined that the microbialites of Lake Alchichica fix N2 to thrive under the N-limiting conditions of the lake, and that these nitrogenase activity peaks are related to heterocystous cyanobacteria that couple photosynthesis to N2 fixation during daylight periods. Heterocystous cyanobacteria (Nostocales) together with Oscillatoriales (non-heterocystous filamentous cyanobacteria) and other cyanobacterial groups have been described as the most abundant cyanobacteria in Alchichica microbialites, and in lithifying mats. Our results suggest that heterocystous cyanobacteria play an important role not only by fixing N2 for biomass construction, but also because their heterocysts host in their external cell membranes main sites for carbonate mineral precipitation including calcium carbonates and siderite. Previous research has shown that the heterocyst is the specialized site for cellular respiration associated to the pH decrease of vegetative/photosynthetic cells, contributing thus to the precipitation of carbonates and the accretion of the organosedimentary structure

  5. Adiponectin plays an important role in efficient energy usage under energy shortage.

    PubMed

    Saito, Kiyomi; Arata, Satoru; Hosono, Tomohiko; Sano, Yoshihiro; Takahashi, Katsuhiko; Choi-Miura, Nam-Ho; Nakano, Yasuko; Tobe, Takashi; Tomita, Motowo

    2006-07-01

    Adiponectin is an adipose tissue-specific secretory protein known to be an insulin-sensitizing protein. In this study, we generated adiponectin sense and antisense transgenic (Tg) mice to investigate whether adiponectin plays a role in the regulation of energy homeostasis during the growth stage. Spontaneous motor activity of antisense Tg mice were markedly reduced during fasting, particularly in young female mice, compared with wild type (Wt) and sense Tg mice. Furthermore, both body weight and adipose tissue mass of the antisense female Tg mice drastically reduced during fasting. To examine the relationship between the collapse of abdominal white adipose tissue (WAT) and serum adiponectin level, we measured the expression of genes related to energy expenditure, such as uncoupling protein (UCP). Notably, the mRNA of UCP1 in the WAT of antisense Tg female mice was markedly less than that of Wt mice and the UCP1 mRNA was strongly increased during fasting. These findings suggest that the serum adiponectin is important to maintaining energy homeostasis under energy shortage conditions, such as over female pubertal development.

  6. Efflux pump gene hefA of Helicobacter pylori plays an important role in multidrug resistance

    PubMed Central

    Liu, Zhi-Qiang; Zheng, Peng-Yuan; Yang, Ping-Chang

    2008-01-01

    AIM: To determine whether efflux systems contribute to multidrug resistance of H pylori. METHODS: A chloramphenicol-induced multidrug resistance model of six susceptible H pylori strains (5 isolates and H pylori NCTC11637) was developed. Multidrug-resistant (MDR) strains were selected and the minimal inhibitory concentration (MIC) of erythromycin, metronidazole, penicillin G, tetracycline, and ciprofloxacin in multidrug resistant strains and their parent strains was determined by agar dilution tests. The level of mRNA expression of hefA was assessed by fluorescence real-time quantitative PCR. A H pylori LZ1026 knockout mutant (ΔH pylori LZ1026) for (putative) efflux protein was constructed by inserting the kanamycin resistance cassette from pEGFP-N2 into hefA, and its susceptibility profiles to 10 antibiotics were evaluated. RESULTS: The MIC of six multidrug-resistant strains (including 5 clinical isolates and H pylori NCTC11637) increased significantly (≥ 4-fold) compared with their parent strains. The expression level of hefA gene was significantly higher in the MDR strains than in their parent strains (P = 0.033). A H pylori LZ1026 mutant was successfully constructed and the ΔH pylori LZ1026 was more susceptible to four of the 10 antibiotics. All the 20 strains displayed transcripts for hefA that confirmed the in vitro expression of these genes. CONCLUSION: The efflux pump gene hefA plays an important role in multidrug resistance of H pylori. PMID:18777600

  7. Basal Transcription Factor 3 Plays an Important Role in Seed Germination and Seedling Growth of Rice

    PubMed Central

    Wang, Wenyi; Xu, Mengyun; Wang, Ya

    2014-01-01

    BTF3 has been recognized to be involved in plant growth and development. But its function remains mostly unknown during seed germination and seedling stage. Here, we have analyzed OsBTF3-related sequences in Oryza sativa L. subspecies, japonica, which resembles with the conserved domain of a nascent polypeptide associated complex (NAC) with different homologs of OsBTF3 and human BTF3. Inhibition of Osj10gBTF3 has led to considerable morphological changes during seed germination and seedling growth. Germination percentage was not influenced by the application of GA3, ABA, and NaCl but all concentrations caused wild-type (WT) seeds to germinate more rapidly than the RNAi (Osj10gBTF3Ri) transgenic lines. Seedling inhibition was more severe in the Osj10gBTF3Ri seedlings compared with their WT especially when treated with 100 or 200 μM GA3; 50% reduction in shoots was observed in Osj10gBTF3Ri seedlings. The expression of Osj3g1BTF3, Osj3g2BTF3 and Osj10gBTF3 was primarily constitutive and generally modulated by NaCl, ABA, and GA3 stresses in both Osj10gBTF3Ri lines and WT at the early seedling stage, suggesting that Osj3g1BTF3 and Osj10gBTF3 are much similar but different from Osj3g2BTF3 in biological function. These results show that OsBTF3 plays an important role in seed germination and seedling growth gives a new perception demonstrating that more multifaceted regulatory functions are linked with BTF3 in plants. PMID:24971328

  8. LOX-1 plays an important role in ischemia-induced angiogenesis of limbs.

    PubMed

    Shiraki, Takeru; Aoyama, Takuma; Yokoyama, Chiharu; Hayakawa, Yuka; Tanaka, Toshiki; Nishigaki, Kazuhiko; Sawamura, Tatsuya; Minatoguchi, Shinya

    2014-01-01

    LOX-1, lectin-like oxidized low-density lipoprotein (LDL) receptor-1, is a single transmembrane receptor mainly expressed on endothelial cells. LOX-1 mediates the uptake of oxidized LDL, an early step in atherosclerosis; however, little is known about whether LOX-1 is involved in angiogenesis during tissue ischemia. Therefore, we examined the role of LOX-1 in ischemia-induced angiogenesis in the hindlimbs of LOX-1 knockout (KO) mice. Angiogenesis was evaluated in a surgically induced hindlimb ischemia model using laser Doppler blood flowmetry (LDBF) and histological capillary density (CD) and arteriole density (AD). After right hindlimb ischemia, the ischemic/nonischemic hindlimb blood flow ratio was persistently lower in LOX-1 KO mice than in wild-type (WT) mice. CD and AD were significantly smaller in LOX-1 KO mice than in WT mice on postoperative day 14. Immunohistochemical analysis revealed that the number of macrophages infiltrating ischemic tissues was significantly smaller in LOX-1 KO mice than in WT mice. The number of infiltrated macrophages expressing VEGF was also significantly smaller in LOX-1 KO mice than in WT mice. Western blot analysis and ROS production assay revealed that LOX- KO mice show significant decrease in Nox2 expression, ROS production and HIF-1α expression, the phosphorylation of p38 MAPK and NF-κB p65 subunit as well as expression of redox-sensitive vascular cell adhesion molecule-1 (VCAM-1) and LOX-1 itself in ischemic muscles, which is supposed to be required for macrophage infiltration expressing angiogenic factor VEGF. Reduction of VEGF expression successively suppressed the phosphorylation of Akt and eNOS, which accelerated angiogenesis, in the ischemic leg of LOX-1 KO mice. Our findings indicate that LOX-1 plays an important role in ischemia-induced angiogenesis by 1) Nox2-ROS-NF-κB activation, 2) upregulated expression of adhesion molecules: VCAM-1 and LOX-1 and 3) promoting macrophage infiltration, which expresses angiogenic

  9. Subequatorial cytoplasm plays an important role in ectoderm patterning in the sea urchin embryo.

    PubMed

    Kominami, Tetsuya; Akagawa, Megumi; Takata, Hiromi

    2006-02-01

    To gain information on the process of ectoderm patterning, the animal halves of sea urchin embryos were isolated at various stages, and their morphology was examined when control embryos developed into pluteus larvae. The animal halves separated at the 8-cell stage developed into 'dauerblastula', without showing any conspicuous ectoderm differentiation. In contrast, some of the animal halves isolated at the 60-cell stage (after the sixth cleavage) formed a ciliated band and oral opening, suggesting that some patterning signal was transmitted from the vegetal to animal hemisphere during early cleavage. Further patterning of the animal hemisphere did not seem to occur until hatching, since both the animal halves isolated at the 60-cell stage and hatching stage showed the same degree of ectoderm patterning. After hatching, the later animal halves were isolated, the more patterned ectoderm they formed. The animal halves isolated just prior to gastrulation differentiated well-patterned ectoderm. It is of note, however, that the level of separation was a more crucial factor than the timing of separation; even the animal fragments of newly hatched embryos differentiated well-patterned ectoderm if they had been separated at a subequatorial level. This suggests that the signal for ectoderm patterning is transmitted over the equator after hatching, and once the cells in the supra-equatorial region receive the signal, they, in turn, can transmit the signal upwardly. Interestingly, if the third cleavage plane was shifted toward the vegetal pole, the isolated animal pole-side fragments developed into 'embryoids' with fully patterned ectoderm. These results indicate that not the micromere descendants but the subequatorial cytoplasm plays an important role in ectoderm patterning.

  10. Galectin-3 Plays an Important Role in Innate Immunity to Gastric Infection by Helicobacter pylori.

    PubMed

    Park, Ah-Mee; Hagiwara, Satoru; Hsu, Daniel K; Liu, Fu-Tong; Yoshie, Osamu

    2016-04-01

    We studied the role of galectin-3 (Gal3) in gastric infection by Helicobacter pylori We first demonstrated that Gal3 was selectively expressed by gastric surface epithelial cells and abundantly secreted into the surface mucus layer. We next inoculated H. pylori Sydney strain 1 into wild-type (WT) and Gal3-deficient mice using a stomach tube. At 2 weeks postinoculation, the bacterial cells were mostly trapped within the surface mucus layer in WT mice. In sharp contrast, they infiltrated deep into the gastric glands in Gal3-deficient mice. Bacterial loads in the gastric tissues were also much higher in Gal3-deficient mice than in WT mice. At 6 months postinoculation,H. pylori had successfully colonized within the gastric glands of both WT and Gal3-deficient mice, although the bacterial loads were still higher in the latter. Furthermore, large lymphoid clusters mostly consisting of B cells were frequently observed in the gastric submucosa of Gal3-deficient mice.In vitro, peritoneal macrophages from Gal3-deficient mice were inefficient in killing engulfed H. pylori Furthermore, recombinant Gal3 not only induced rapid aggregation of H. pylori but also exerted a potent bactericidal effect on H. pylori as revealed by propidium iodide uptake and a morphological shift from spiral to coccoid form. However, a minor fraction of bacterial cells, probably transient phase variants of Gal3-binding sugar moieties, escaped killing by Gal3. Collectively, our data demonstrate that Gal3 plays an important role in innate immunity to infection and colonization of H. pylori.

  11. LvDJ-1 plays an important role in resistance against Vibrio alginolyticus in Litopenaeus vannamei.

    PubMed

    Huang, Mingzhu; Liu, Yuan; Xie, Chenying; Wang, Wei-Na

    2015-05-01

    DJ-1 was first identified as an oncogene that transformed mouse NIH3T3 cells in cooperation with activated Ras. It has since exhibited a variety of functions in a range of organisms. In this study, the DJ-1 gene in Litopenaeus vannamei (LvDJ-1) was identified and characterized. A recombinant protein LvDJ-1 was produced in Pichia pastoris. LvDJ-1 expression in vivo was knocked down by dsRNA-mediated RNA interference (RNAi), which led to significantly decreased levels of LvDJ-1 mRNA and protein. When the L. vannamei were challenged with RNAi and Vibrio alginolyticus, the transcription and expression of copper zinc superoxide dismutase (LvCZSOD) in the hepatopancreas were dramatically lower in shrimp with knocked down LvDJ-1 than in controls. Transcription and expression of P53 (LvP53) were significantly higher in shrimp lacking LvDJ-1 than in controls. Hepatopancreas samples were analyzed using real time polymerase chain reaction and Western blot. Moreover, blood samples from the shrimp, assessed with flow cytometry, showed significant increases in respiratory burst and apoptosis in those lacking LvDJ-1 compared to the controls. Cumulative mortality in the shrimp lacking LvDJ-1 was significantly different from that in the control group after challenge with V. alginolyticus. Altogether, the results prove that LvDJ-1 regulates apoptosis and antioxidant activity, and that these functions play an important role in L. vannamei resistance against V. alginolyticus.

  12. Proprotein convertases play an important role in regulating PKGI endoproteolytic cleavage and nuclear transport

    PubMed Central

    Kato, Shin; Zhang, Ruiguang

    2013-01-01

    Nitric oxide and cGMP modulate vascular smooth muscle cell (SMC) phenotype by regulating cell differentiation and proliferation. Recent studies suggest that cGMP-dependent protein kinase I (PKGI) cleavage and the nuclear translocation of a constitutively active kinase fragment, PKGIγ, are required for nuclear cGMP signaling in SMC. However, the mechanisms that control PKGI proteolysis are unknown. Inspection of the amino acid sequence of a PKGI cleavage site that yields PKGIγ and a protease database revealed a putative minimum consensus sequence for proprotein convertases (PCs). Therefore we investigated the role of PCs in regulating PKGI proteolysis. We observed that overexpression of PCs, furin and PC5, but not PC7, which are all expressed in SMC, increase PKGI cleavage in a dose-dependent manner in human embryonic kidney (HEK) 293 cells. Moreover, furin-induced proteolysis of mutant PKGI, in which alanines were substituted into the putative PC consensus sequence, was decreased in these cells. In addition, overexpression of furin increased PKGI proteolysis in LoVo cells, which is an adenocarcinoma cell line expressing defective furin without PC activity. Also, expression of α1-PDX, an engineered serpin-like PC inhibitor, reduced PC activity and decreased PKGI proteolysis in HEK293 cells. Last, treatment of low-passage rat aortic SMC with membrane-permeable PC inhibitor peptides decreased cGMP-stimulated nuclear PKGIγ translocation. These data indicate for the first time that PCs have a role in regulating PKGI proteolysis and the nuclear localization of its active cleavage product, which are important for cGMP-mediated SMC phenotype. PMID:23686857

  13. Missense SLC25A38 variations play an important role in autosomal recessive inherited sideroblastic anemia

    PubMed Central

    Kannengiesser, Caroline; Sanchez, Mayka; Sweeney, Marion; Hetet, Gilles; Kerr, Briedgeen; Moran, Erica; Fuster Soler, Jose L.; Maloum, Karim; Matthes, Thomas; Oudot, Caroline; Lascaux, Axelle; Pondarré, Corinne; Sevilla Navarro, Julian; Vidyatilake, Sudharma; Beaumont, Carole; Grandchamp, Bernard; May, Alison

    2011-01-01

    Background Congenital sideroblastic anemias are rare disorders with several genetic causes; they are characterized by erythroblast mitochondrial iron overload, differ greatly in severity and some occur within a syndrome. The most common cause of non-syndromic, microcytic sideroblastic anemia is a defect in the X-linked 5-aminolevulinate synthase 2 gene but this is not always present. Recently, variations in the gene for the mitochondrial carrier SLC25A38 were reported to cause a non-syndromic, severe type of autosomal-recessive sideroblastic anemia. Further evaluation of the importance of this gene was required to estimate the proportion of patients affected and to gain further insight into the range and types of variations involved. Design and Methods In three European diagnostic laboratories sequence analysis of SLC25A38 was performed on DNA from patients affected by congenital sideroblastic anemia of a non-syndromic nature not caused by variations in the 5-aminolevulinate synthase 2 gene. Results Eleven patients whose ancestral origins spread across several continents were homozygous or compound heterozygous for ten different SLC25A38 variations causing premature termination of translation (p.Arg117X, p.Tyr109LeufsX43), predicted splicing alteration (c.625G>C; p.Asp209His) or missense substitution (p.Gln56Lys, p.Arg134Cys, p.Ile147Asn, p.Arg187Gln, p.Pro190Arg, p.Gly228Val, p.Arg278Gly). Only three of these variations have been described previously (p.Arg117X, p.Tyr109LeufsX43 and p.Asp209His). All new variants reported here are missense and affect conserved amino acids. Structure modeling suggests that these variants may influence different aspects of transport as described for mutations in other mitochondrial carrier disorders. Conclusions Mutations in the SLC25A38 gene cause severe, non-syndromic, microcytic/hypochromic sideroblastic anemia in many populations. Missense mutations are shown to be of importance as are mutations that affect protein production

  14. Soil water content plays an important role in soil-atmosphere exchange of carbonyl sulfide (OCS)

    NASA Astrophysics Data System (ADS)

    Yi, Zhigang; Behrendt, Thomas; Bunk, Rüdiger; Wu, Dianming; Kesselmeier, Jürgen

    2016-04-01

    Carbonyl sulfide (OCS) is a quite stable gas in the troposphere and is transported up to the stratosphere, where it contributes to the sulfate aerosol layer (Crutzen 1976). The tropospheric concentration seems to be quite constant, indicating a balance between sinks and sources. Recent work by Sandoval-Soto et al. (2005) demonstrated the enormous strength of the vegetation sink and the urgent needs to understand the sinks and sources. The role of soils is a matter of discussion (Kesselmeier et al., 1999; Van Diest and Kesselmeier, 2008; Maseyk et al., 2014; Whelan et al., 2015). To better understand the influence of soil water content and OCS mixing ratio on OCS fluxes, we used an OCS analyzer (LGR COS/CO Analyzer 907-0028, Los Gatos, CA, USA) coupled with automated soil chamber system (Behrendt et al., 2014) to measure the OCS fluxes with a slow drying of four different types of soil (arable wheat soil in Mainz, blueberry soil in Waldstein, spruce soil in Waldstein and needle forest soil in Finland). Results showed that OCS fluxes as well as the optimum soil water content for OCS uptake varied significantly for different soils. The net production rates changed significantly with the soil drying out from 100% to about 5% water holding capacity (WHC), implying that soil water content play an important role in the uptake processes. The production and uptake processes were distinguished by the regression of OCS fluxes under different OCS mixing ratios. OCS compensation points (CP) were found to differ significantly for different soil types and water content, with the lowest CP at about 20% WHC, implying that when estimating the global budgets of OCS, especially for soils fluxes, soil water content should be taken into serious consideration. References Crutzen, P. J. 1976, Geophys. Res. Lett., 3, 73-76. Sandoval-Soto, L. et al., 2005, Biogeosciences, 2, 125-132. Kesselmeier, J. et al., 1999, J. Geophys. Res., 104, 11577-11584. Van Diest, H. and Kesselmeier, J. 2008

  15. 78 FR 77771 - Culturally Significant Object Imported for Exhibition Determinations: “Love and Play: A Pair of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Object Imported for Exhibition Determinations: ``Love and Play: A Pair of Paintings by..., I hereby determine that the object to be included in the exhibition ``Love and Play: A Pair...

  16. Acid-Tolerant Sulfate-Reducing Bacteria Play a Major Role in Iron Cycling in Acidic Iron Rich Sediments

    NASA Astrophysics Data System (ADS)

    Enright, K. A.; Moreau, J. W.

    2008-12-01

    acidic conditions. The dsrAB genes are related to other novel SRB lineages derived from acidic environments in previous reports, suggesting that these species have adapted to the acidity rather than colonized more circumneutral microenvironments. In an acidic hypersaline lake system in NW Victoria (Australia), previous studies suggested that pore water bisulfide derived from anoxic groundwater transported from distal locations. However, isolated potholes of oxic Fe(III)-rich springwater exhibited nearly a two-fold increase in conductivity and pH increase from 4.5 to 8.0 over time periods on the order of days; and biogeochemical and mineralogical observations were consistent with the presence of active acid- and halo-tolerant SRB. Furthermore, stratified active microbial mat communities, with zones of black FeS formation localized several millimeters below the sediment-air interface, were identified in cross-section from lakeshore sediments near groundwater discharge springs. Culture-independent and culture-based work to characterize the SRB population is ongoing at this site. We infer, from previous sulfur isotope tracer experiments at the lake, that overall sulfate reduction rates may be slow, but are nonetheless proceeding and contributing to the recycling of oxidized iron to a significant degree given the abundance of sulfate evidenced by widespread gypsum precipitation. We conclude from the two study-sites described above that acid-tolerant SRB species play an important role in the linked S, Fe and C cycles in acidifying, iron-rich environments, and their phylogenetic and physiological diversity should be further investigated.

  17. p21 induction plays a dual role in anti-cancer activity of ursolic acid

    PubMed Central

    Zhang, Xudong; Song, Xinhua; Yin, Shutao; Zhao, Chong; Fan, Lihong

    2015-01-01

    Previous studies have shown that induction of G1 arrest and apoptosis by ursolic acid is associated with up-regulation of cyclin-dependent kinase inhibitor (CDKI) protein p21 in multiple types of cancer cells. However, the functional role of p21 induction in G1 cell cycle arrest and apoptosis, and the mechanisms of p21 induction by ursolic acid have not been critically addressed. In the current study, we demonstrated that p21 played a mediator role in G1 cell cycle arrest by ursolic acid, whereas p21-mediated up-regulation of Mcl-1 compromised apoptotic effect of ursolic acid. These results suggest that p21 induction plays a dual role in the anti-cancer activity of ursolic acid in terms of cell cycle and apoptosis regulation. p21 induction by ursolic acid was attributed to p53 transcriptional activation. Moreover, we found that ursolic acid was able to inhibit murine double minute-2 protein (MDM2) and T-LAK cell-originated protein kinase (TOPK), the two negative regulator of p53, which in turn contributed to ursolic acid-induced p53 activation. Our findings provided novel insights into understanding of the mechanisms involved in cell cycle arrest and apoptosis induction in response to ursolic acid exposure. PMID:26582056

  18. Interaction of SDF-1alpha and CXCR4 plays an important role in pulmonary cellular infiltration in differentiation syndrome.

    PubMed

    Zhou, Jin; Hu, Longhu; Cui, Zhe; Jiang, Xian; Wang, Guifang; Krissansen, Geoffrey W; Sun, Xueying

    2010-03-01

    This study aims to investigate the role of stromal cell-derived factor 1alpha (SDF-1alpha) and its receptor CXCR4 in cellular infiltration of the lung in differentiation syndrome (DS). The acute promyelocytic leukemia (APL) NB4 cells and freshly prepared APL cells from the patients were differentiated by all-trans retinoic acid (ATRA). The expression of SDF-1alpha in human lung tissues was examined by RT-PCR and Western blot analysis. The cells were subjected to adhesion, migration or invasion assays, and co-cultured with human lung tissues in a microgravity rotary cell culture system to examine cellular infiltration in situ. ATRA-differentiated cells expressed high levels of CXCR4, and adhered more strongly to matrigel. Their ability to migrate and invade was enhanced by SDF-1alpha and lung homogenate, and diminished by pre-treatment with an anti-CXCR4 blocking antibody. SDF-1alpha was expressed in the lung tissues of all seven human donors. ATRA-differentiated NB4 cells infiltrated into lung tissues, and this was reduced by pre-treatment with an anti-CXCR4 blocking antibody. The interaction of SDF-1alpha and CXCR4 plays an important role in pulmonary cellular infiltration during DS, suggesting that targeting SDF-1alpha and CXCR4 may provide the basis for potential treatments in the management of DS.

  19. Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

    PubMed Central

    Mahanty, Arabinda; Sankar, T. V.; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md.; Debnath, Dipesh; Vijayagopal, P.; Sridhar, N.; Akhtar, M. S.; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Das, Debajeet; Das, Pushpita; Vijayan, K. K.; Laxmanan, P. T.; Sharma, A. P.

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. PMID:25379285

  20. Amino Acid compositions of 27 food fishes and their importance in clinical nutrition.

    PubMed

    Mohanty, Bimal; Mahanty, Arabinda; Ganguly, Satabdi; Sankar, T V; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md; Debnath, Dipesh; Vijayagopal, P; Sridhar, N; Akhtar, M S; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Paria, Prasenjit; Das, Debajeet; Das, Pushpita; Vijayan, K K; Laxmanan, P T; Sharma, A P

    2014-01-01

    Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs.

  1. Myocardin marks the earliest cardiac gene expression and plays an important role in heart development.

    PubMed

    Chen, Jian-Fu; Wang, Shusheng; Wu, Qiulian; Cao, Dongsun; Nguyen, Thiha; Chen, Yiping; Wang, Da-Zhi

    2008-10-01

    Myocardin belongs to the SAP domain family of transcription factors and is expressed specifically in cardiac and smooth muscle during embryogenesis and in adulthood. Myocardin functions as a transcriptional coactivator of SRF and is sufficient and necessary for smooth muscle gene expression. However, the in vivo function of myocardin during cardiogenesis is not completely understood. Here we clone myocardin from chick embryonic hearts and show that myocardin protein sequences are highly conserved cross species. Detailed studies of chick myocardin expression reveal that myocardin is expressed in cardiac and smooth muscle lineage during early embryogenesis, similar to that found in mouse. Interestingly, the expression of myocardin in the heart was found enriched in the outflow tract and the sinoatrial segments shortly after the formation of linear heart tube. Such expression pattern is also maintained in later developing embryos, suggesting that myocardin may play a unique role in the formation of those cardiac modules. Similar to its mouse counterpart, chick myocardin is able to activate cardiac and smooth muscle promoter reporter genes and induce smooth muscle gene expression in nonmuscle cells. Ectopic overexpression of myocardin enlarged the embryonic chick heart. Conversely, repression of the endogenous chick myocardin using antisense oligonucleotides or a dominant negative mutant form of myocardin inhibited cardiogenesis. Together, our data place myocardin as one of the earliest cardiac marker genes for cardiogenesis and support the idea that myocardin plays an essential role in cardiac gene expression and cardiogenesis.

  2. Cationic amino acid transporters play key roles in the survival and transmission of apicomplexan parasites

    PubMed Central

    Rajendran, Esther; Hapuarachchi, Sanduni V.; Miller, Catherine M.; Fairweather, Stephen J.; Cai, Yeping; Smith, Nicholas C.; Cockburn, Ian A.; Bröer, Stefan; Kirk, Kiaran; van Dooren, Giel G.

    2017-01-01

    Apicomplexans are obligate intracellular parasites that scavenge essential nutrients from their hosts via transporter proteins on their plasma membrane. The identities of the transporters that mediate amino acid uptake into apicomplexans are unknown. Here we demonstrate that members of an apicomplexan-specific protein family—the Novel Putative Transporters (NPTs)—play key roles in the uptake of cationic amino acids. We show that an NPT from Toxoplasma gondii (TgNPT1) is a selective arginine transporter that is essential for parasite survival and virulence. We also demonstrate that a homologue of TgNPT1 from the malaria parasite Plasmodium berghei (PbNPT1), shown previously to be essential for the sexual gametocyte stage of the parasite, is a cationic amino acid transporter. This reveals a role for cationic amino acid scavenging in gametocyte biology. Our study demonstrates a critical role for amino acid transporters in the survival, virulence and life cycle progression of these parasites. PMID:28205520

  3. Cationic amino acid transporters play key roles in the survival and transmission of apicomplexan parasites.

    PubMed

    Rajendran, Esther; Hapuarachchi, Sanduni V; Miller, Catherine M; Fairweather, Stephen J; Cai, Yeping; Smith, Nicholas C; Cockburn, Ian A; Bröer, Stefan; Kirk, Kiaran; van Dooren, Giel G

    2017-02-16

    Apicomplexans are obligate intracellular parasites that scavenge essential nutrients from their hosts via transporter proteins on their plasma membrane. The identities of the transporters that mediate amino acid uptake into apicomplexans are unknown. Here we demonstrate that members of an apicomplexan-specific protein family-the Novel Putative Transporters (NPTs)-play key roles in the uptake of cationic amino acids. We show that an NPT from Toxoplasma gondii (TgNPT1) is a selective arginine transporter that is essential for parasite survival and virulence. We also demonstrate that a homologue of TgNPT1 from the malaria parasite Plasmodium berghei (PbNPT1), shown previously to be essential for the sexual gametocyte stage of the parasite, is a cationic amino acid transporter. This reveals a role for cationic amino acid scavenging in gametocyte biology. Our study demonstrates a critical role for amino acid transporters in the survival, virulence and life cycle progression of these parasites.

  4. Dysregulation of JAM-A plays an important role in human tumor progression.

    PubMed

    Zhao, Chen; Lu, Funian; Chen, Hongxia; Zhao, Xianda; Sun, Jun; Chen, Honglei

    2014-01-01

    Junctional adhesion molecule A (JAM-A) is a transmembrane protein that belongs to the immunoglobulin (Ig) superfamily. Evidence determines that JAM-A plays a role in numerous cellular processes, including tight junction assembly, leukocyte migration, platelet activation, angiogenesis and virus binding. Recent research suggests that JAM-A is dysregulated in various cancers and is vital for tumor progression. JAM-A is implicated in carcinogenesis via different signal pathways such as TGF-β1 signaling. Furthermore, JAM-A expression in cancers is usually associated with certain outcome of patients and might be a prognostic indicator. In this review, the correlation between JAM-A expression and human cancers will be described.

  5. Neutrophil extracellular Taps play an important role in clearance of Streptococcus suis in vivo.

    PubMed

    Zhao, Jianqing; Lin, Lan; Fu, Lei; Han, Li; Zhang, Anding

    2016-04-01

    Streptococcus suis infection induces formation of neutrophil extracellular traps (NETs) in vitro; however, the contribution of NETs-mediated killing to the pathogenesis of S. suis in vivo is yet to be elicited. The findings of the present study indicated that extracellular DNA fiber can be induced in a murine model in response to S. suis infection. A nuclease that destroys their structure was used to evaluate the role of NETs on S. suis infection. Treatment with nuclease resulted in a greater bacteria load and higher serum TNF-α concentrations in response to S. suis infection, indicating that NETs structure played an essential role in S. suis clearance and inflammation. Furthermore, nuclease treatment resulted in more severe clinical signs during and higher mortality from S. suis infection. These findings indicated that NETs structure contributes to protection against S. suis infection.

  6. Hepatic Induction of Fatty Acid Binding Protein 4 Plays a Pathogenic Role in Sepsis in Mice.

    PubMed

    Hu, Bingfang; Li, Yujin; Gao, Li; Guo, Yan; Zhang, Yiwen; Chai, Xiaojuan; Xu, Meishu; Yan, Jiong; Lu, Peipei; Ren, Songrong; Zeng, Su; Liu, Yulan; Xie, Wen; Huang, Min

    2017-03-06

    Sepsis is defined as the host's deleterious systemic inflammatory response to microbial infections. Herein, we report an essential role of the fatty acid binding protein 4 (FABP4; alias adipocyte protein 2 or aP2), a lipid-binding chaperone, in sepsis response. Bioinformatic analysis of the Gene Expression Omnibus data sets showed the level of FABP4 was higher in the nonsurvival sepsis patients' whole blood compared to the survival cohorts. The expression of Fabp4 was induced in a liver-specific manner in cecal ligation and puncture (CLP) and lipopolysaccharide treatment models of sepsis. The induction of Fabp4 may have played a pathogenic role, because ectopic expression of Fabp4 in the liver sensitized mice to CLP-induced inflammatory response and worsened the animal's survival. In contrast, pharmacological inhibition of Fabp4 markedly alleviated the CLP responsive inflammation and tissue damage and improved survival. We conclude that FABP4 is an important mediator of the sepsis response. Early intervention by pharmacological inhibition of FABP4 may help to manage sepsis in the clinic.

  7. The stringent response plays a key role in Bacillus subtilis survival of fatty acid starvation.

    PubMed

    Pulschen, André A; Sastre, Diego E; Machinandiarena, Federico; Crotta Asis, Agostina; Albanesi, Daniela; de Mendoza, Diego; Gueiros-Filho, Frederico J

    2017-02-01

    The stringent response is a universal adaptive mechanism to protect bacteria from nutritional and environmental stresses. The role of the stringent response during lipid starvation has been studied only in Gram-negative bacteria. Here, we report that the stringent response also plays a crucial role in the adaptation of the model Gram-positive Bacillus subtilis to fatty acid starvation. B. subtilis lacking all three (p)ppGpp-synthetases (RelBs , RelP and RelQ) or bearing a RelBs variant that no longer synthesizes (p)ppGpp suffer extreme loss of viability on lipid starvation. Loss of viability is paralleled by perturbation of membrane integrity and function, with collapse of membrane potential as the likely cause of death. Although no increment of (p)ppGpp could be detected in lipid starved B. subtilis, we observed a substantial increase in the GTP/ATP ratio of strains incapable of synthesizing (p)ppGpp. Artificially lowering GTP with decoyinine rescued viability of such strains, confirming observations that low intracellular GTP is important for survival of nutritional stresses. Altogether, our results show that activation of the stringent response by lipid starvation is a broadly conserved response of bacteria and that a key role of (p)ppGpp is to couple biosynthetic processes that become detrimental if uncoordinated.

  8. Intragenic CpG islands play important roles in bivalent chromatin assembly of developmental genes.

    PubMed

    Lee, Sun-Min; Lee, Jungwoo; Noh, Kyung-Min; Choi, Won-Young; Jeon, Sejin; Oh, Goo Taeg; Kim-Ha, Jeongsil; Jin, Yoonhee; Cho, Seung-Woo; Kim, Young-Joon

    2017-03-07

    CpG, 5'-C-phosphate-G-3', islands (CGIs) have long been known for their association with enhancers, silencers, and promoters, and for their epigenetic signatures. They are maintained in embryonic stem cells (ESCs) in a poised but inactive state via the formation of bivalent chromatin containing both active and repressive marks. CGIs also occur within coding sequences, where their functional role has remained obscure. Intragenic CGIs (iCGIs) are largely absent from housekeeping genes, but they are found in all genes associated with organ development and cell lineage control. In this paper, we investigated the epigenetic status of iCGIs and found that they too reside in bivalent chromatin in ESCs. Cell type-specific DNA methylation of iCGIs in differentiated cells was linked to the loss of both the H3K4me3 and H3K27me3 marks, and disruption of physical interaction with promoter regions, resulting in transcriptional activation of key regulators of differentiation such as PAXs, HOXs, and WNTs. The differential epigenetic modification of iCGIs appears to be mediated by cell type-specific transcription factors distinct from those bound by promoter, and these transcription factors may be involved in the hypermethylation of iCGIs upon cell differentiation. iCGIs thus play a key role in the cell type-specific regulation of transcription.

  9. Did large animals play an important role in global biogeochemical cycling in the past?

    NASA Astrophysics Data System (ADS)

    Doughty, C.

    2014-12-01

    In the late Pleistocene (~50-10,000 years ago), ninety-seven genera of large animals (>44kg) (megafauna) went extinct, concentrated in the Americas and Australia. The loss of megafauna had major effects on ecosystem structure, seed dispersal and land surface albedo. However, the impact of this dramatic extinction on ecosystem nutrient biogeochemistry, through the lateral transport of dung and bodies, has never been explored. Here we explore these nutrient impacts using a novel mathematical framework that analyses this lateral transport as a diffusion-like process and demonstrates that large animals play a disproportionately large role in the horizontal transfer of nutrients across landscapes. For example, we estimate that the extinction of the Amazonian megafauna led to a >98% reduction in the lateral transfer flux of the limiting nutrient phosphorus (P) with similar, though less extreme, decreases in all continents outside of Africa. This resulted in strong decreases in phosphorus availability in Eastern Amazonia away from fertile floodplains, a decline which may still be ongoing, and current P limitation in the Amazon basin may be partially a relic of an ecosystem without the functional connectedness it once had. More broadly, the Pleistocene megafaunal extinctions resulted in major and ongoing disruptions to terrestrial biogeochemical cycling at continental scales and increased nutrient heterogeneity globally.

  10. Growth temperature and genotype both play important roles in sorghum grain phenolic composition.

    PubMed

    Wu, Gangcheng; Johnson, Stuart K; Bornman, Janet F; Bennett, Sarita J; Clarke, Michael W; Singh, Vijaya; Fang, Zhongxiang

    2016-02-24

    Polyphenols in sorghum grains are a source of dietary antioxidants. Polyphenols in six diverse sorghum genotypes grown under two day/night temperature regimes of optimal temperature (OT, 32/21 °C and high temperature (HT, 38/21 °C) were investigated. A total of 23 phenolic compounds were positively or tentatively identified by HPLC-DAD-ESIMS. Compared with other pigmented types, the phenolic profile of white sorghum PI563516 was simpler, since fewer polyphenols were detected. Brown sorghum IS 8525 had the highest levels of caffeic and ferulic acid, but apigenin and luteolin were not detected. Free luteolinidin and apigeninidin levels were lower under HT than OT across all genotypes (p ≤ 0.05), suggesting HT could have inhibited 3-deoxyanthocyanidins formation. These results provide new information on the effects of HT on specific polyphenols in various Australian sorghum genotypes, which might be used as a guide to grow high antioxidant sorghum grains under projected high temperature in the future.

  11. Growth temperature and genotype both play important roles in sorghum grain phenolic composition

    PubMed Central

    Wu, Gangcheng; Johnson, Stuart K.; Bornman, Janet F.; Bennett, Sarita J.; Clarke, Michael W.; Singh, Vijaya; Fang, Zhongxiang

    2016-01-01

    Polyphenols in sorghum grains are a source of dietary antioxidants. Polyphenols in six diverse sorghum genotypes grown under two day/night temperature regimes of optimal temperature (OT, 32/21 °C and high temperature (HT, 38/21 °C) were investigated. A total of 23 phenolic compounds were positively or tentatively identified by HPLC-DAD-ESIMS. Compared with other pigmented types, the phenolic profile of white sorghum PI563516 was simpler, since fewer polyphenols were detected. Brown sorghum IS 8525 had the highest levels of caffeic and ferulic acid, but apigenin and luteolin were not detected. Free luteolinidin and apigeninidin levels were lower under HT than OT across all genotypes (p ≤ 0.05), suggesting HT could have inhibited 3-deoxyanthocyanidins formation. These results provide new information on the effects of HT on specific polyphenols in various Australian sorghum genotypes, which might be used as a guide to grow high antioxidant sorghum grains under projected high temperature in the future. PMID:26907726

  12. Gravity Plays an Important Role in Muscle Development and the Differentiation of Contractile Protein Phenotype

    NASA Technical Reports Server (NTRS)

    Adams, Gregory A.; Haddad, Fadia; Baldwin, Kenneth M.

    2003-01-01

    Several muscles in the body exist mainly to work against gravity. Whether gravity is important in the development of these muscles is not known. By examining the basic proteins that compose muscle, questions about the role of gravity in muscle development can be answered. Myosin heavy chains (MHCs) are a family of proteins critically important for muscle contraction. Several types of MHCs exist (e.g., neonatal, slow, fast), and each type is produced by a particular gene. Neonatal MHCs are produced early in life. Slow MHCs are important in antigravity muscles, and fast MHCs are found in fast-twitch power muscles. The gene that is turned on or expressed will determine which MHC is produced. Early in development, antigravity skeletal muscles (muscles that work against gravity) normally produce a combination of the neonatal/embryonic MHCs. The expression of these primitive MHCs is repressed early in development; and the adult slow and fast MHC genes become fully expressed. We tested the hypothesis that weightbearing activity is critical for inducing the normal expression of the slow MHC gene typically expressed in adult antigravity muscles. Also, we hypothesized that thyroid hormone, but not opposition to gravity, is necessary for expressing the adult fast IIb MHC gene essential for high-intensity muscle performance. Groups of normal thyroid and thyroid-deficient neonatal rats were studied after their return from the 16-day Neurolab mission and compared to matched controls. The results suggest: (1) Weightlessness impaired body and limb skeletal muscle growth in both normal and thyroid-deficient animals. Antigravity muscles were impaired more than those used primarily for locomotion andor nonweightbearing activity. (2) Systemic and muscle expression of insulin-like growth factor-I (IGF-I), an important body and tissue growth factor, was depressed in flight animals. (3) Normal slow, type I MHC gene expression was markedly repressed in the normal thyroid flight group. (4

  13. Polymer Stability Plays an Important Role in the Positional Regulation of FtsZ

    PubMed Central

    Levin, Petra Anne; Schwartz, Rachel L.; Grossman, Alan D.

    2001-01-01

    We conducted a series of experiments examining the effect of polymer stability on FtsZ localization dynamics in Bacillus subtilis. A loss-of-function mutation in ezrA, a putative polymer-destabilizing factor, suppresses the defects in FtsZ polymer stability associated with minCD overexpression. In addition, a mutation that is predicted to stabilize the FtsZ polymer leads to the formation of polar FtsZ rings. These data support the hypothesis that carefully balanced polymer stability is important for the assembly and localization of FtsZ during the bacterial cell cycle. PMID:11514533

  14. Migrating monocytes recruited to the spleen play an important role in control of blood stage malaria.

    PubMed

    Sponaas, Anne-Marit; Freitas do Rosario, Ana Paula; Voisine, Cecile; Mastelic, Beatris; Thompson, Joanne; Koernig, Sandra; Jarra, William; Renia, Laurent; Mauduit, Marjorie; Potocnik, Alexandre J; Langhorne, Jean

    2009-12-24

    Host responses controlling blood-stage malaria include both innate and acquired immune effector mechanisms. During Plasmodium chabaudi infection in mice, a population of CD11b(high)Ly6C(+) monocytes are generated in bone marrow, most of which depend on the chemokine receptor CCR2 for migration from bone marrow to the spleen. In the absence of this receptor mice harbor higher parasitemias. Most importantly, splenic CD11b(high)Ly6C(+) cells from P chabaudi-infected wild-type mice significantly reduce acute-stage parasitemia in CCR2(-/-) mice. The CD11b(high)Ly6C(+) cells in this malaria infection display effector functions such as production of inducible nitric oxide synthase and reactive oxygen intermediates, and phagocytose P chabaudi parasites in vitro, and in a proportion of the cells, in vivo in the spleen, suggesting possible mechanisms of parasite killing. In contrast to monocyte-derived dendritic cells, CD11b(high)Ly6C(+) cells isolated from malaria-infected mice express low levels of major histocompatibility complex II and have limited ability to present the P chabaudi antigen, merozoite surface protein-1, to specific T-cell receptor transgenic CD4 T cells and fail to activate these T cells. We propose that these monocytes, which are rapidly produced in the bone marrow as part of the early defense mechanism against invading pathogens, are important for controlling blood-stage malaria parasites.

  15. The novel zinc cluster regulator Tog1 plays important roles in oleate utilization and oxidative stress response in Saccharomyces cerevisiae

    SciTech Connect

    Thepnok, Piyasuda; Ratanakhanokchai, Khanok; Soontorngun, Nitnipa

    2014-08-08

    Highlights: • TOG1 deletion results in defective growth on non-fermentable carbon sources. • Removal of TOG1 sensitizes cells to oxidative stress. • Tog1 directly binds and activates expression of oleate utilizing genes. • The Δtog1 cells display reduced peroxisomal content in oleate culture. • S. cerevisiae zinc cluster Tog1 is a novel activator of oleate utilization. - Abstract: Many zinc cluster proteins have been shown to play a role in the transcriptional regulation of glucose-repressible genes during glucose exhaustion and diauxic shift. Here, we studied an additional member of this family called Yer184c (herein called Tog1) for transcriptional regulator of oleate. Our results showed that a Δtog1 strain displays impaired growth with several non-fermentable carbons. Tog1 is also implicated in oxidative stress tolerance. Importantly, during the glucose–oleate shift, combined results from quantitative real time-PCR and chromatin immunoprecipitation (ChIP) experiments showed that Tog1 acts as a direct activator of oleate utilizing genes, encoded key enzymes in β-Oxidation and NADPH regeneration (POX1, FOX2, POT1 and IDP2), the glyoxylate shunt (MLS1 and ICL1), and gluconeogenesis (PCK1 and FBP1). A transmission electron microscopy (TEM) analysis of the Δtog1 strain assayed with oleate also revealed a substantial decrease in peroxisome abundance that is vital for fatty acid oxidation. Overall, our results clearly demonstrated that Tog1 is a newly characterized zinc cluster regulator that functions in the complex network of non-fermentable carbon metabolism in Saccharomycescerevisiae.

  16. Autophagy plays an important role in Sunitinib-mediated cell death in H9c2 cardiac muscle cells

    SciTech Connect

    Zhao Yuqin; Xue Tao; Yang Xiaochun; Zhu Hong; Ding Xiaofei; Lou Liming; Lu Wei; Yang Bo; He Qiaojun

    2010-10-01

    Sunitinib, which is a multitargeted tyrosine-kinase inhibitor, exhibits antiangiogenic and antitumor activity, and extends survival of patients with metastatic renal-cell carcinoma (mRCC) and gastrointestinal stromal tumors (GIST). This molecule has also been reported to be associated with cardiotoxicity at a high frequency, but the mechanism is still unknown. In the present study, we observed that Sunitinib showed high anti-proliferative effect on H9c2 cardiac muscle cells measured by PI staining and the MTT assay. But apoptotic markers (PARP cleavage, caspase 3 cleavage and chromatin condensation) were uniformly negative in H9c2 cells after Sunitinib treatment for 48 h, indicating that another cell death pathway may be involved in Sunitinib-induced cardiotoxicity. Here we found Sunitinib dramatically increased autophagic flux in H9c2 cells. Acidic vesicle fluorescence and high expression of LC3-II in H9c2 cells identified autophagy as a Sunitinib-induced process that might be associated with cytotoxicity. Furthermore, knocking down Beclin 1 by RNA-interference to block autophagy in H9c2 cells revealed that the death rate was decreased when treated with Sunitinib in comparison to control cells. These results confirmed that autophagy plays an important role in Sunitinib-mediated H9c2 cells cytotoxicity. Taken together, the data presented here strongly suggest that autophagy is associated with Sunitinib-induced cardiotoxicity, and that inhibition of autophagy constitutes a viable strategy for reducing Sunitinib-induced cardiomyocyte death thereby alleviating Sunitinib cardiotoxicity.

  17. Mechanisms underlying skeletal muscle insulin resistance induced by fatty acids: importance of the mitochondrial function

    PubMed Central

    2012-01-01

    Insulin resistance condition is associated to the development of several syndromes, such as obesity, type 2 diabetes mellitus and metabolic syndrome. Although the factors linking insulin resistance to these syndromes are not precisely defined yet, evidence suggests that the elevated plasma free fatty acid (FFA) level plays an important role in the development of skeletal muscle insulin resistance. Accordantly, in vivo and in vitro exposure of skeletal muscle and myocytes to physiological concentrations of saturated fatty acids is associated with insulin resistance condition. Several mechanisms have been postulated to account for fatty acids-induced muscle insulin resistance, including Randle cycle, oxidative stress, inflammation and mitochondrial dysfunction. Here we reviewed experimental evidence supporting the involvement of each of these propositions in the development of skeletal muscle insulin resistance induced by saturated fatty acids and propose an integrative model placing mitochondrial dysfunction as an important and common factor to the other mechanisms. PMID:22360800

  18. Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise.

    PubMed

    Zheng, Xinyan; Hasegawa, Hiroshi

    2016-10-01

    Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.

  19. Transposons play an important role in the evolution and diversification of centromeres among closely related species.

    PubMed

    Gao, Dongying; Jiang, Ning; Wing, Rod A; Jiang, Jiming; Jackson, Scott A

    2015-01-01

    Centromeres are important chromosomal regions necessary for eukaryotic cell segregation and replication. Due to high amounts of tandem repeats and transposons, centromeres have been difficult to sequence in most multicellular organisms, thus their sequence structure and evolution are poorly understood. In this study, we analyzed transposons in the centromere 8 (Cen8) from the African cultivated rice (O. glaberrima) and two subspecies of the Asian cultivated rice (O. sativa), indica and japonica. We detected much higher transposon contents (>69%) in centromere regions than in the whole genomes of O. sativa ssp. japonica and O. glaberrima (~35%). We compared the three Cen8s and identified numerous recent insertions of transposons that were frequently organized into multiple-layer nested blocks, similar to nested transposons in maize. Except for the Hopi retrotransposon, all LTR retrotransposons were shared but exhibit different abundances amongst the three Cen8s. Even though a majority of the transposons were located in intergenic regions, some gene-related transposons were found and may be involved in gene diversification. Chromatin immunoprecipitated (ChIP) data analysis revealed that 165 families from both Class I and Class II transposons were found in CENH3-associated chromatin sequences. These results indicate essential roles for transposons in centromeres and that the rapid divergence of the Cen8 sequences between the two cultivated rice species was primarily caused by recent transposon insertions.

  20. Intracellularly induced cyclophilins play an important role in stress adaptation and virulence of Brucella abortus.

    PubMed

    Roset, Mara S; García Fernández, Lucía; DelVecchio, Vito G; Briones, Gabriel

    2013-02-01

    Brucella is an intracellular bacterial pathogen that causes the worldwide zoonotic disease brucellosis. Brucella virulence relies on its ability to transition to an intracellular lifestyle within host cells. Thus, this pathogen must sense its intracellular localization and then reprogram gene expression for survival within the host cell. A comparative proteomic investigation was performed to identify differentially expressed proteins potentially relevant for Brucella intracellular adaptation. Two proteins identified as cyclophilins (CypA and CypB) were overexpressed in the intracellular environment of the host cell in comparison to laboratory-grown Brucella. To define the potential role of cyclophilins in Brucella virulence, a double-deletion mutant was constructed and its resulting phenotype was characterized. The Brucella abortus ΔcypAB mutant displayed increased sensitivity to environmental stressors, such as oxidative stress, pH, and detergents. In addition, the B. abortus ΔcypAB mutant strain had a reduced growth rate at lower temperature, a phenotype associated with defective expression of cyclophilins in other microorganisms. The B. abortus ΔcypAB mutant also displays reduced virulence in BALB/c mice and defective intracellular survival in HeLa cells. These findings suggest that cyclophilins are important for Brucella virulence and survival in the host cells.

  1. Platelets play an important role in TNF-induced microvascular endothelial cell pathology.

    PubMed Central

    Lou, J.; Donati, Y. R.; Juillard, P.; Giroud, C.; Vesin, C.; Mili, N.; Grau, G. E.

    1997-01-01

    Tumor necrosis factor-alpha (TNF) is known to be an important mediator in the pathogenesis of several inflammatory diseases. Vascular endothelial cells represent a major target of TNF effects. Platelet sequestration has been found in brain microvessels during experimental cerebral malaria and lung in experimental pulmonary fibrosis, implying that it may participate in TNF-dependent microvascular pathology. In this study, we investigated the mechanisms of platelet-endothelial interaction, using co-cultures between platelets and TNF-activated mouse brain microvascular endothelial cells (MVECs). Adhesion and fusion of platelets to MVECs was evidenced by electron microscopy, dye transfer, and flow cytometry. It was induced by TNF and interferon-gamma and depended on LFA-1 expressed on the platelet surface and ICAM-1 expressed on MVECs. The adhesion and fusion also led to the transfer of platelet markers on the MVEC surface, rendering these more adherent for leukocytes, and to an enhanced MVEC sensitivity to TNF-induced injury. These results suggest that platelets can participate in TNF-induced microvascular pathology. Images Figure 2 Figure 3 Figure 6 PMID:9358766

  2. Ohr plays a central role in bacterial responses against fatty acid hydroperoxides and peroxynitrite.

    PubMed

    Alegria, Thiago G P; Meireles, Diogo A; Cussiol, José R R; Hugo, Martín; Trujillo, Madia; de Oliveira, Marcos Antonio; Miyamoto, Sayuri; Queiroz, Raphael F; Valadares, Napoleão Fonseca; Garratt, Richard C; Radi, Rafael; Di Mascio, Paolo; Augusto, Ohara; Netto, Luis E S

    2017-01-10

    Organic hydroperoxide resistance (Ohr) enzymes are unique Cys-based, lipoyl-dependent peroxidases. Here, we investigated the involvement of Ohr in bacterial responses toward distinct hydroperoxides. In silico results indicated that fatty acid (but not cholesterol) hydroperoxides docked well into the active site of Ohr from Xylella fastidiosa and were efficiently reduced by the recombinant enzyme as assessed by a lipoamide-lipoamide dehydrogenase-coupled assay. Indeed, the rate constants between Ohr and several fatty acid hydroperoxides were in the 10(7)-10(8) M(-1)⋅s(-1) range as determined by a competition assay developed here. Reduction of peroxynitrite by Ohr was also determined to be in the order of 10(7) M(-1)⋅s(-1) at pH 7.4 through two independent competition assays. A similar trend was observed when studying the sensitivities of a ∆ohr mutant of Pseudomonas aeruginosa toward different hydroperoxides. Fatty acid hydroperoxides, which are readily solubilized by bacterial surfactants, killed the ∆ohr strain most efficiently. In contrast, both wild-type and mutant strains deficient for peroxiredoxins and glutathione peroxidases were equally sensitive to fatty acid hydroperoxides. Ohr also appeared to play a central role in the peroxynitrite response, because the ∆ohr mutant was more sensitive than wild type to 3-morpholinosydnonimine hydrochloride (SIN-1 , a peroxynitrite generator). In the case of H2O2 insult, cells treated with 3-amino-1,2,4-triazole (a catalase inhibitor) were the most sensitive. Furthermore, fatty acid hydroperoxide and SIN-1 both induced Ohr expression in the wild-type strain. In conclusion, Ohr plays a central role in modulating the levels of fatty acid hydroperoxides and peroxynitrite, both of which are involved in host-pathogen interactions.

  3. Children's Right to Play: An Examination of the Importance of Play in the Lives of Children Worldwide. Working Papers in Early Childhood Development, No. 57

    ERIC Educational Resources Information Center

    Lester, Stuart; Russell, Wendy

    2010-01-01

    In this working paper, Wendy Russell and Stuart Lester of the UK's University of Gloucestershire discuss why play is fundamental to the health and well-being of children. They argue that both state signatories to the United Nations Convention on the Rights of the Child (Article 31 of which enshrines the right to play) and adults generally should…

  4. Autophagy plays an important role in protecting Pacific oysters from OsHV-1 and Vibrio aestuarianus infections.

    PubMed

    Moreau, Pierrick; Moreau, Kevin; Segarra, Amélie; Tourbiez, Delphine; Travers, Marie-Agnès; Rubinsztein, David C; Renault, Tristan

    2015-01-01

    Recent mass mortality outbreaks around the world in Pacific oysters, Crassostrea gigas, have seriously affected the aquaculture economy. Although the causes for these mortality outbreaks appear complex, infectious agents are involved. Two pathogens are associated with mass mortality outbreaks, the virus ostreid herpesvirus 1 (OsHV-1) and the bacterium Vibrio aestuarianus. Here we describe the interactions between these 2 pathogens and autophagy, a conserved intracellular pathway playing a key role in innate immunity. We show for the first time that autophagy pathway is present and functional in Pacific oysters and plays an important role to protect animals from infections. This study contributes to better understand the innate immune system of Pacific oysters.

  5. Autophagy plays an important role in protecting Pacific oysters from OsHV-1 and Vibrio aestuarianus infections

    PubMed Central

    Moreau, Pierrick; Moreau, Kevin; Segarra, Amélie; Tourbiez, Delphine; Travers, Marie-Agnès; Rubinsztein, David C; Renault, Tristan

    2015-01-01

    Recent mass mortality outbreaks around the world in Pacific oysters, Crassostrea gigas, have seriously affected the aquaculture economy. Although the causes for these mortality outbreaks appear complex, infectious agents are involved. Two pathogens are associated with mass mortality outbreaks, the virus ostreid herpesvirus 1 (OsHV-1) and the bacterium Vibrio aestuarianus. Here we describe the interactions between these 2 pathogens and autophagy, a conserved intracellular pathway playing a key role in innate immunity. We show for the first time that autophagy pathway is present and functional in Pacific oysters and plays an important role to protect animals from infections. This study contributes to better understand the innate immune system of Pacific oysters. PMID:25714877

  6. Polyamine biosynthesis regulated by StARD expression plays an important role in potato wound periderm formation.

    PubMed

    Kim, Jae Hyun; Kim, Hyun Soon; Lee, Yong Hwa; Kim, Yoon Sik; Oh, Hyun Woo; Joung, Hyouk; Chae, Suhn Kee; Suh, Kyong Hoon; Jeon, Jae Heung

    2008-10-01

    An acireductone dioxygenase (ARD) gene of potatoes was isolated from the expressed sequence tags (ESTs) of potato post-suberization cDNA libraries. The highest expression levels of the StARD gene and the protein appeared 36 h after suberization. An approximate 9-fold increase in ARD activity was detected at 36 h after wounding. Real-time reverse transcription-PCR (RT-PCR) analysis and immunolocalization studies revealed that StARD transcripts increase at the wound surface of potato tubers. The polyamine (PA) contents increased significantly after wounding at the wound surface. The increased PA content and ARD activity may play an important role in wound periderm formation.

  7. Mast cells play an important role in Chlamydia pneumoniae lung infection by facilitating immune cell recruitment into the airway

    PubMed Central

    Chiba, Norika; Shimada, Kenichi; Chen, Shuang; Jones, Heather D.; Alsabeh, Randa; Slepenkin, Anatoly V.; Peterson, Ellena; Crother, Timothy R.; Arditi, Moshe

    2015-01-01

    Mast cells are known as central players in allergy and anaphylaxis, and play a pivotal role in host defense against certain pathogens. Chlamydia pneumoniae (Cpn) is an important human pathogen, but it is unclear what role mast cells play during Cpn infection. We infected C57BL/6 (WT) and mast cell-deficient mice, Kitw-sh/w-sh (Wsh), with Cpn. Wsh mice showed improved survival than WT, with fewer cells in Wsh BALF despite similar levels of cytokines and chemokines. We also found a more rapid clearance of bacteria from the lungs of Wsh mice compared with WT. Cromolyn, a mast cell stabilizer, reduced BAL cells and bacterial burden similar to Wsh mice; conversely, Compound 48/80, a mast cell degranulator, increased the number of BAL cells and bacterial burden. Histology showed that WT lungs had diffuse inflammation while Wsh mice had patchy accumulations of neutrophils and perivascular accumulations of lymphocytes. Infected Wsh mice had reduced amounts of MMP-9 in BALF and were resistant to epithelial integral membrane protein degradation, suggesting that barrier integrity remains intact in Wsh mice. Mast cell reconstitution in Wsh mice led to enhanced bacterial growth and normal epithelial integral membrane protein degradation, highlighting the specific role of mast cells in this model. These data suggest that mast cells play a detrimental role during Cpn infection by facilitating immune cell infiltration into the airspace and providing a more favorable replicative environment for Cpn. PMID:25754739

  8. SDF-1 and CXCR4 play an important role in adult SVZ lineage cell proliferation and differentiation.

    PubMed

    Zhu, Chang; Yao, Wen-Long; Tan, Wei; Zhang, Chuan-Han

    2017-02-15

    Evidence has shown that stromal cell-derived factor (SDF-1/CXCL12) plays an important role in maintaining adult neural progenitor cells (NPCs). SDF-1 is also known to enhance recovery by recruiting NPCs to damaged regions and recent studies have revealed that SDF-1α exhibits pleiotropism, thereby differentially affecting NPC subpopulations. In this study, we investigated the role of SDF-1 in in vitro NPC self-renewal, proliferation and differentiation, following treatment with different concentrations of SDF-1 or a CXCR4 antagonist, AMD3100. We observed that AMD3100 inhibited the formation of primary neurospheres. However, SDF-1 and AMD3100 exhibited no effect on proliferation upon inclusion of growth factors in the media. Following growth factor withdrawal, AMD3100 and SDF-1 treatment resulted in differential effects on NPC proliferation. SDF-1, at a concentration of 500ng/ml, resulted in an increase in the relative proportion of oligodendrocytes following growth factor withdrawal-induced differentiation. Using CXCR4 knockout mice, we observed that SDF-1 affected NPC proliferation in the sub-ventricular zone (SVZ). We also investigated the occurrence of differential CXCR4 expression at different stages during lineage progression. These results clearly indicate that signaling interactions between SDF-1 and CXCR4 play an important role in adult SVZ lineage cell proliferation and differentiation.

  9. Fungal production of citric and oxalic acid: importance in metal speciation, physiology and biogeochemical processes.

    PubMed

    Gadd, G M

    1999-01-01

    alteration of terrestrial subsurface limestones. Oxalate also plays an important role in lignocellulose degradation and plant pathogenesis, affecting activities of key enzymes and metal oxido-reduction reactions, therefore underpinning one of the most fundamental roles of fungi in carbon cycling in the natural environment. This review discusses the physiology and chemistry of citric and oxalic acid production in fungi, the intimate association of these acids and processes with metal speciation, physiology and mobility, and their importance and involvement in key fungal-mediated processes, including lignocellulose degradation, plant pathogenesis and metal biogeochemistry.

  10. Mast cells play an important role in chlamydia pneumoniae lung infection by facilitating immune cell recruitment into the airway.

    PubMed

    Chiba, Norika; Shimada, Kenichi; Chen, Shuang; Jones, Heather D; Alsabeh, Randa; Slepenkin, Anatoly V; Peterson, Ellena; Crother, Timothy R; Arditi, Moshe

    2015-04-15

    Mast cells are known as central players in allergy and anaphylaxis, and they play a pivotal role in host defense against certain pathogens. Chlamydia pneumoniae is an important human pathogen, but it is unclear what role mast cells play during C. pneumoniae infection. We infected C57BL/6 (wild-type [WT]) and mast cell-deficient mice (Kit(W-sh/W-sh) [Wsh]) with C. pneumoniae. Wsh mice showed improved survival compared with WT mice, with fewer cells in Wsh bronchoalveolar lavage fluid (BALF), despite similar levels of cytokines and chemokines. We also found a more rapid clearance of bacteria from the lungs of Wsh mice compared with WT mice. Cromolyn, a mast cell stabilizer, reduced BALF cells and bacterial burden similar to the levels seen in Wsh mice; conversely, Compound 48/80, a mast cell degranulator, increased the number of BALF cells and bacterial burden. Histology showed that WT lungs had diffuse inflammation, whereas Wsh mice had patchy accumulations of neutrophils and perivascular accumulations of lymphocytes. Infected Wsh mice had reduced amounts of matrix metalloprotease-9 in BALF and were resistant to epithelial integral membrane protein degradation, suggesting that barrier integrity remains intact in Wsh mice. Mast cell reconstitution in Wsh mice led to enhanced bacterial growth and normal epithelial integral membrane protein degradation, highlighting the specific role of mast cells in this model. These data suggest that mast cells play a detrimental role during C. pneumoniae infection by facilitating immune cell infiltration into the airspace and providing a more favorable replicative environment for C. pneumoniae.

  11. The cyclin-dependent kinase inhibitor Orysa;KRP1 plays an important role in seed development of rice.

    PubMed

    Barrôco, Rosa Maria; Peres, Adrian; Droual, Anne-Marie; De Veylder, Lieven; Nguyen, Le Son Long; De Wolf, Joris; Mironov, Vladimir; Peerbolte, Rindert; Beemster, Gerrit T S; Inzé, Dirk; Broekaert, Willem F; Frankard, Valerie

    2006-11-01

    Kip-related proteins (KRPs) play a major role in the regulation of the plant cell cycle. We report the identification of five putative rice (Oryza sativa) proteins that share characteristic motifs with previously described plant KRPs. To investigate the function of KRPs in rice development, we generated transgenic plants overexpressing the Orysa;KRP1 gene. Phenotypic analysis revealed that overexpressed KRP1 reduced cell production during leaf development. The reduced cell production in the leaf meristem was partly compensated by an increased cell size, demonstrating the existence of a compensatory mechanism in monocot species by which growth rate is less reduced than cell production, through cell expansion. Furthermore, Orysa;KRP1 overexpression dramatically reduced seed filling. Sectioning through the overexpressed KRP1 seeds showed that KRP overproduction disturbed the production of endosperm cells. The decrease in the number of fully formed seeds was accompanied by a drop in the endoreduplication of endosperm cells, pointing toward a role of KRP1 in connecting endocycle with endosperm development. Also, spatial and temporal transcript detection in developing seeds suggests that Orysa;KRP1 plays an important role in the exit from the mitotic cell cycle during rice grain formation.

  12. Vaccinia virus A12L protein and its AG/A proteolysis play an important role in viral morphogenic transition

    PubMed Central

    Yang, Su Jung; Hruby, Dennis E

    2007-01-01

    Like the major vaccinia virus (VV) core protein precursors, p4b and p25K, the 25 kDa VV A12L late gene product (p17K) is proteolytically maturated at the conserved Ala-Gly-Ala motif. However, the association of the precursor and its cleavage product with the core of mature virion suggests that both of the A12L proteins may be required for virus assembly. Here, in order to test the requirement of the A12L protein and its proteolysis in viral replication, a conditional lethal mutant virus (vvtetOA12L) was constructed to regulate A12L expression by the presence or absence of an inducer, tetracycline. In the absence of tetracycline, replication of vvtetOA12L was inhibited by 80% and this inhibition could be overcome by transient expression of the wild-type copy of the A12L gene. In contrast, mutation of the AG/A site abrogated the ability of the transfected A12L gene to rescue, indicating that A12L proteolysis plays an important role in viral replication. Electron microscopy analysis of the A12L deficient virus demonstrated the aberrant virus particles, which were displayed by the AG/A site mutation. Thus, we concluded that the not only A12L protein but also its cleavage processing plays an essential role in virus morphogenic transition. PMID:17625005

  13. Dimer monomer transition and dimer re-formation play important role for ATM cellular function during DNA repair

    SciTech Connect

    Du, Fengxia; Zhang, Minjie; Li, Xiaohua; Yang, Caiyun; Meng, Hao; Wang, Dong; Chang, Shuang; Xu, Ye; Price, Brendan; Sun, Yingli

    2014-10-03

    Highlights: • ATM phosphorylates the opposite strand of the dimer in response to DNA damage. • The PETPVFRLT box of ATM plays a key role in its dimer dissociation in DNA repair. • The dephosphorylation of ATM is critical for dimer re-formation after DNA repair. - Abstract: The ATM protein kinase, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks, mediates responses to ionizing radiation in mammalian cells. Here we show that ATM is held inactive in unirradiated cells as a dimer and phosphorylates the opposite strand of the dimer in response to DNA damage. Cellular irradiation induces rapid intermolecular autophosphorylation of serine 1981 that causes dimer dissociation and initiates cellular ATM kinase activity. ATM cannot phosphorylate the substrates when it could not undergo dimer monomer transition. After DNA repair, the active monomer will undergo dephosphorylation to form dimer again and dephosphorylation is critical for dimer re-formation. Our work reveals novel function of ATM dimer monomer transition and explains why ATM dimer monomer transition plays such important role for ATM cellular activity during DNA repair.

  14. The Photographic History of Greenland's Glaciers - and how the historical data plays an important role in today's glacier research

    NASA Astrophysics Data System (ADS)

    Bjork, A. A.; Kjeldsen, K. K.; Korsgaard, N. J.; Aagaard, S.; Andresen, C. S.; Bamber, J. L.; van den Broeke, M.; Colgan, W. T.; Funder, S.; Khan, S. A.; Larsen, N. K.; Machguth, H.; Nuth, C.; Schomacker, A.; Kjaer, K. H.

    2015-12-01

    As the Greenland Ice Sheet and Greenland's glaciers are continuing to loss mass at high rates, knowledge of their past response to climatic changes is ever important. By harvesting the archives for images, both terrestrial and airborne, we are able to expand the record of glacier observation by several decades, thus supplying crucial knowledge on glacier behavior to important climatic transitions such as the end of the Little Ice Age and the early 20th Century warming. Here we show how a large collection of historical aerial images portray the glacial response to the Little Ice Age deglaciation in Greenland and document frontal change throughout the 20th Century. A detailed story of the LIA-deglaciation is told by supplementing with terrestrial photos that capture the onset of retreat and high resolution aerial images that portray geomorphological evidence of the Little Ice Age maximum extent. This work is the result of several generations of Greenland researches and their efforts to portray and document the state of the glaciers, and highlights that while interpretations and conclusions may be challenged and changed through time, the raw observations remain extremely valuable. Finally, we also show how archival data besides photos may play an important role in future glacier research in Greenland.

  15. Geographic location, sex and nutritional status play an important role in body image concerns among Brazilian adolescents.

    PubMed

    Laus, Maria Fernanda; Miranda, Valter Paulo Neves; Almeida, Sebastião Sousa; Braga Costa, Telma Maria; Ferreira, Maria Elisa Caputo

    2013-03-01

    This study compared body image concerns among adolescents from different geographic locations in Brazil, and the influence of sex and nutritional status. Seven hundred eighty-eight adolescents completed the Body Shape Questionnaire (BSQ) and had their weight and height measured. There were significant cross-regional differences in BSQ scores. Also, body image concerns were more prevalent among girls and among overweight adolescents. It is suggested that sex and nutritional status may play an important role in body image concerns, which is more common between adolescents from urban areas. Furthermore, our findings contribute to the literature by examining patterns of body image concerns within subgroups of adolescents who have received little research attention on these issues.

  16. Dimer monomer transition and dimer re-formation play important role for ATM cellular function during DNA repair.

    PubMed

    Du, Fengxia; Zhang, Minjie; Li, Xiaohua; Yang, Caiyun; Meng, Hao; Wang, Dong; Chang, Shuang; Xu, Ye; Price, Brendan; Sun, Yingli

    2014-10-03

    The ATM protein kinase, is a serine/threonine protein kinase that is recruited and activated by DNA double-strand breaks, mediates responses to ionizing radiation in mammalian cells. Here we show that ATM is held inactive in unirradiated cells as a dimer and phosphorylates the opposite strand of the dimer in response to DNA damage. Cellular irradiation induces rapid intermolecular autophosphorylation of serine 1981 that causes dimer dissociation and initiates cellular ATM kinase activity. ATM cannot phosphorylate the substrates when it could not undergo dimer monomer transition. After DNA repair, the active monomer will undergo dephosphorylation to form dimer again and dephosphorylation is critical for dimer re-formation. Our work reveals novel function of ATM dimer monomer transition and explains why ATM dimer monomer transition plays such important role for ATM cellular activity during DNA repair.

  17. Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance[S

    PubMed Central

    Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

    2015-01-01

    Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a “push” (synthesis) and “pull” (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses. PMID:26323290

  18. Sumoylation of the P protein at K254 plays an important role in growth of parainfluenza virus 5.

    PubMed

    Sun, Dengyun; Xu, Pei; He, Biao

    2011-10-01

    The P protein of parainfluenza virus 5 (PIV5) is an essential cofactor of the viral RNA-dependent RNA polymerase. Phosphorylation of the P protein can positively or negatively regulate viral gene expression, depending on the precise phosphorylation sites. Sumoylation, a process of adding small ubiquitin-like modifier (SUMO) to proteins posttranslationally, plays an important role in regulating protein function. In this study, we have found that the P protein of PIV5 was sumoylated with SUMO1 in both transfected and infected cells. The K254 residue of the P protein is within a consensus sumoylation motif. Mutation of the P protein at K254 to arginine (P-K254R) reduced PIV5 minigenome activity, as well as the sumoylation level of the P protein. Incorporation of K254R into a recombinant PIV5 (rPIV5-P-K254R) resulted in a virus that grew to a lower titer and had lower levels of viral RNA synthesis and protein expression than wild-type PIV5, suggesting that sumoylation of the P protein at K254 is important for PIV5 growth. Biochemical studies did not reveal any defect of P-K254R in its interactions with viral proteins NP and L or formation of homotetramers. We propose that sumoylation of the P protein at K254 regulates PIV5 gene expression through a host protein.

  19. Cyclic electron flow plays an important role in photoprotection for the resurrection plant Paraboea rufescens under drought stress.

    PubMed

    Huang, Wei; Yang, Shi-Jian; Zhang, Shi-Bao; Zhang, Jiao-Lin; Cao, Kun-Fang

    2012-04-01

    Resurrection plants could survive severe drought stress, but the underlying mechanism for protecting their photosynthetic apparatus against drought stress is unclear. Cyclic electron flow (CEF) has been documented as a crucial mechanism for photoprotection in Arabidopsis and tobacco. We hypothesized that CEF plays an important role in protecting photosystem I (PSI) and photosystem II (PSII) against drought stress for resurrection plants. To address this hypothesis, the effects of mild drought stress on light energy distribution in PSII and P700 redox state were examined in a resurrection plant Paraboea rufescens. Cyclic electron flow was not activated below the photosynthetic photon flux density (PPFD) of 400 μmol m⁻² s⁻¹ in leaves without drought stress. However, CEF was activated under low light in leaves with mild drought stress, and the effective quantum yield of PSII significantly decreased. Meanwhile, non-photochemical quenching (NPQ) was significantly stimulated not only under high light but also under low light. Compared with the control, the fraction of overall P700 that cannot be oxidized in a given state (PSI acceptor side limitation) under high light was maintained at low level of 0.1 in leaves with water deficit, indicating that the over-reduction of the PSI acceptor side was prevented by the significant stimulation of CEF. Furthermore, methyl viologen could significantly increase the PSII photo-inhibition induced by high light compared with chloramphenicol. These results suggested that CEF is an important mechanism for protecting PSI and PSII from drought stress in resurrection plants.

  20. The Endothelial Tyrosine Phosphatase SHP-1 Plays an Important Role for Vascular Haemostasis in TNFα-Induced Inflammation In Vivo

    PubMed Central

    Koch, Elisabeth; Pircher, Joachim; Czermak, Thomas; Gaitzsch, Erik; Alig, Stefan; Mannell, Hanna; Niemeyer, Markus; Krötz, Florian; Wörnle, Markus

    2013-01-01

    Introduction. Inflammation and endothelium-derived superoxides are important pathomechanisms in atherothrombotic diseases. We could previously show that the tyrosine phosphatase SHP-1 acts as a negative regulator in endothelial superoxide production. In this study we investigated the influence of SHP-1 on platelet-endothelium interaction and arterial thrombosis in TNFα-induced endothelial inflammation in vivo. Methods. Arteriolar thrombosis and platelet rolling in vivo were investigated in C57BL/6 mice using intravital microscopy in the dorsal skinfold chamber microcirculation model. Results. Inhibition of SHP-1 by the specific pharmacological inhibitor sodium stibogluconate did not significantly enhance platelet-endothelium interaction in vivo under physiological conditions but led to an augmented fraction of rolling platelets in TNFα-induced systemic inflammation. Accordingly, ferric-chloride-induced arteriolar thrombus formation, which was already increased by SHP-1 inhibition, was further enhanced in the setting of TNFα-induced inflammation. Platelet aggregation in vitro as well as ex vivo was not influenced by SHP-1-inhibition. In cultured endothelial cells, sodium stibogluconate increased TNFα-induced surface expression of p-selectin and von Willebrand factor. Additionally, TNFα increased SHP-1 activity and protein expression. Conclusions. The endothelial tyrosine phosphatase SHP-1 plays an important role for vascular hemostasis in vivo, which is crucial in TNFα-induced endothelial inflammation where it may serve as an autoinhibitory molecule to prevent excess inflammatory response and thrombus formation. PMID:23766558

  1. Nutrition metabolism plays an important role in the alternate bearing of the olive tree (Olea europaea L.).

    PubMed

    Turktas, Mine; Inal, Behcet; Okay, Sezer; Erkilic, Emine Gulden; Dundar, Ekrem; Hernandez, Pilar; Dorado, Gabriel; Unver, Turgay

    2013-01-01

    The olive tree (Olea europaea L.) is widely known for its strong tendency for alternate bearing, which severely affects the fruit yield from year to year. Microarray based gene expression analysis using RNA from olive samples (on-off years leaves and ripe-unripe fruits) are particularly useful to understand the molecular mechanisms influencing the periodicity in the olive tree. Thus, we carried out genome wide transcriptome analyses involving different organs and temporal stages of the olive tree using the NimbleGen Array containing 136,628 oligonucleotide probe sets. Cluster analyses of the genes showed that cDNAs originated from different organs could be sorted into separate groups. The nutritional control had a particularly remarkable impact on the alternate bearing of olive, as shown by the differential expression of transcripts under different temporal phases and organs. Additionally, hormonal control and flowering processes also played important roles in this phenomenon. Our analyses provide further insights into the transcript changes between "on year" and "off year" leaves along with the changes from unrpipe to ripe fruits, which shed light on the molecular mechanisms underlying the olive tree alternate bearing. These findings have important implications for the breeding and agriculture of the olive tree and other crops showing periodicity. To our knowledge, this is the first study reporting the development and use of an olive array to document the gene expression profiling associated with the alternate bearing in olive tree.

  2. Proteomic profiling analysis reveals that glutathione system plays important roles responding to osmotic stress in wheat (Triticum aestivum L.) roots

    PubMed Central

    Dong, Wen; Zhang, Daijing; Gao, Xiaolong; Shao, Yun; Tong, Doudou

    2016-01-01

    Wheat is one of the most important crops in the world, and osmotic stress has become one of the main factors affecting wheat production. Understanding the mechanism of the response of wheat to osmotic stress would be greatly significant. In the present study, isobaric tag for relative and absolute quantification (iTRAQ) was used to analyze the changes of protein expression in the wheat roots exposed to different osmotic stresses. A total of 2,228 expressed proteins, including 81 differentially expressed proteins, between osmotic stress and control, were found. The comprehensive analysis of these differentially expressed proteins revealed that osmotic stress increased the variety of expressed proteins and suppressed the quantity of expressed proteins in wheat roots. Furthermore, the proteins for detoxifying and reactive oxygen species scavenging, especially the glutathione system, played important roles in maintaining organism balance in response to osmotic stress in wheat roots. Thus, the present study comprehensively describes the protein expression changes in wheat roots in response to osmotic stress, providing firmer foundation to further study the mechanism of osmotic resistance in wheat. PMID:27602297

  3. Nutrition Metabolism Plays an Important Role in the Alternate Bearing of the Olive Tree (Olea europaea L.)

    PubMed Central

    Turktas, Mine; Inal, Behcet; Okay, Sezer; Erkilic, Emine Gulden; Dundar, Ekrem; Hernandez, Pilar; Dorado, Gabriel; Unver, Turgay

    2013-01-01

    The olive tree (Olea europaea L.) is widely known for its strong tendency for alternate bearing, which severely affects the fruit yield from year to year. Microarray based gene expression analysis using RNA from olive samples (on-off years leaves and ripe-unripe fruits) are particularly useful to understand the molecular mechanisms influencing the periodicity in the olive tree. Thus, we carried out genome wide transcriptome analyses involving different organs and temporal stages of the olive tree using the NimbleGen Array containing 136,628 oligonucleotide probe sets. Cluster analyses of the genes showed that cDNAs originated from different organs could be sorted into separate groups. The nutritional control had a particularly remarkable impact on the alternate bearing of olive, as shown by the differential expression of transcripts under different temporal phases and organs. Additionally, hormonal control and flowering processes also played important roles in this phenomenon. Our analyses provide further insights into the transcript changes between ”on year” and “off year” leaves along with the changes from unrpipe to ripe fruits, which shed light on the molecular mechanisms underlying the olive tree alternate bearing. These findings have important implications for the breeding and agriculture of the olive tree and other crops showing periodicity. To our knowledge, this is the first study reporting the development and use of an olive array to document the gene expression profiling associated with the alternate bearing in olive tree. PMID:23555820

  4. Ruminal Prevotella spp. May Play an Important Role in the Conversion of Plant Lignans into Human Health Beneficial Antioxidants

    PubMed Central

    Schogor, Ana L. B.; Huws, Sharon A.; Santos, Geraldo T. D.; Scollan, Nigel D.; Hauck, Barbara D.; Winters, Ana L.; Kim, Eun J.; Petit, Hélène V.

    2014-01-01

    Secoisolariciresinol diglucoside (SDG), the most abundant lignan in flaxseed, is metabolized by the ruminal microbiota into enterolignans, which are strong antioxidants. Enterolactone (EL), the main mammalian enterolignan produced in the rumen, is transferred into physiological fluids, with potentially human health benefits with respect to menopausal symptoms, hormone-dependent cancers, cardiovascular diseases, osteoporosis and diabetes. However, no information exists to our knowledge on bacterial taxa that play a role in converting plant lignans into EL in ruminants. In order to investigate this, eight rumen cannulated cows were used in a double 4×4 Latin square design and fed with four treatments: control with no flax meal (FM), or 5%, 10% and 15% FM (on a dry matter basis). Concentration of EL in the rumen increased linearly with increasing FM inclusion. Total rumen bacterial 16S rRNA concentration obtained using Q-PCR did not differ among treatments. PCR-T-RFLP based dendrograms revealed no global clustering based on diet indicating between animal variation. PCR-DGGE showed a clustering by diet effect within four cows that had similar basal ruminal microbiota. DNA extracted from bands present following feeding 15% FM and absent with no FM supplementation were sequenced and it showed that many genera, in particular Prevotella spp., contributed to the metabolism of lignans. A subsequent in vitro study using selected pure cultures of ruminal bacteria incubated with SDG indicated that 11 ruminal bacteria were able to convert SDG into secoisolariciresinol (SECO), with Prevotella spp. being the main converters. These data suggest that Prevotella spp. is one genus playing an important role in the conversion of plant lignans to human health beneficial antioxidants in the rumen. PMID:24709940

  5. Genetic diversity analysis reveals that geographical environment plays a more important role than rice cultivar in Villosiclava virens population selection.

    PubMed

    Wang, Fei; Zhang, Shu; Liu, Mei-Gang; Lin, Xian-Song; Liu, Hui-Jiang; Peng, You-Liang; Lin, Yang; Huang, Jun-Bin; Luo, Chao-Xi

    2014-05-01

    Rice false smut caused by Villosiclava virens is an economically important disease of grains worldwide. The genetic diversity of 153 isolates from six fields located in Wuhan (WH), Yichang Wangjia (YCW), Yichang Yaohe (YCY), Huanggang (HG), Yangxin (YX), and Jingzhou (JZ) in Hubei province of China were phylogenetically analyzed to evaluate the influence of environments and rice cultivars on the V. virens populations. Isolates (43) from Wuhan were from two rice cultivars, Wanxian 98 and Huajing 952, while most of the other isolates from fields YCW, YCY, HG, YX, and JZ originated from different rice cultivars with different genetic backgrounds. Genetic diversity of isolates was analyzed using random amplified polymorphic DNA (RAPD) and single-nucleotide polymorphisms (SNP). The isolates from the same cultivars in Wuhan tended to group together, indicating that the cultivars had an important impact on the fungal population. The 110 isolates from individual fields tended to cluster according to geographical origin. The values of Nei's gene diversity (H) and Shannon's information index (I) showed that the genetic diversity among isolates was higher between than within geographical populations. Furthermore, mean genetic distance between groups (0.006) was higher than mean genetic distance within groups (0.0048) according to MEGA 5.2. The pairwise population fixation index (FST) values also showed significant genetic differentiation between most populations. Higher genetic similarity of isolates from individual fields but different rice cultivars suggested that the geographical factor played a more important role in the selection of V. virens isolates than rice cultivars. This information could be used to improve the management strategy for rice false smut by adjusting the cultivation measures, such as controlling fertilizer, water, and planting density, in the rice field to change the microenvironment.

  6. NAC transcription factors play an important role in ethylene biosynthesis, reception and signaling of tomato fruit ripening.

    PubMed

    Kou, Xiaohong; Liu, Chen; Han, Lihua; Wang, Shuang; Xue, Zhaohui

    2016-06-01

    NAC proteins comprise a large family of transcription factors that play important roles in diverse physiological processes during development. To explore the role of NAC transcription factors in the ripening of fruits, we predicted the secondary and tertiary structure as well as regulative function of the SNAC4 (SlNAC48, Accession number: NM 001279348.2) and SNAC9 (SlNAC19, Accession number: XM 004236996.2) transcription factors in tomato. We found that the tertiary structure of SNAC9 was similar to that of ATNAP, which played an important role in the fruit senescence and was required for ethylene stimulation. Likewise, the bio-function prediction results indicated that SNAC4 and SNAC9 participated in various plant hormone signaling and senescence processes. More information about SNACs was obtained by the application of VIGS (virus-induced gene silencing). The silencing of SNAC4 and SNAC9 dramatically repressed the LeACS2, LeACS4 and LeACO1 expression, which consequently led to the inhibition of the ripening process. The silencing of SNACs down-regulated the mRNA levels of the ethylene perception genes and, at the same time, suppressed the expression of ethylene signaling-related genes except for LeERF2 which was induced by the silencing of SNAC4. The expressions of LeRIN were different in two silenced fruits. In addition, the silencing of SNAC4 reduced its mRNA level, while the silencing of SNAC9 induced its expression. Furthermore, the silencing of LeACS4, LeACO1 and LeERF2 reduced the expression of SNAC4 and SNAC9, while the silencing of NR induced the expression of all of them. In particular, these results indicate that SNAC transcription factors bind to the promoter of the ethylene synthesis genes in vitro. This experimental evidence demonstrates that SNAC4 and SNAC9 could positively regulate the tomato fruit ripening process by functioning upstream of ethylene synthesis genes. These outcomes will be helpful to provide a theoretical foundation for further

  7. Geography Plays a More Important Role than Soil Composition on Structuring Genetic Variation of Pseudometallophyte Commelina communis

    PubMed Central

    Li, Jiaokun; Xu, Hui; Song, Yunpeng; Tang, Lulu; Gong, Yanbing; Yu, Runlan; Shen, Li; Wu, Xueling; Liu, Yuandong; Zeng, Weimin

    2016-01-01

    Pseudometallophytes are excellent models to study microevolution and local adaptation to soil pollution, as they can grow both on metalliferous and contrasting non-metalliferous soils. Although, there has been accumulating evidence for the effects of edaphic conditions and geographical isolation on the genetic structure of pesudometallophytes, it is still a difficult problem in evolutionary biology to assess their relative importance. In this study, we investigated the spatial patterns of genetic variability, population differentiation and genetic groups in pseudometallophyte Commelina communis with 12 microsatellite loci. Eight metallicolous and six non-metallicolous populations of C. communis were sampled from cupriferous sites and surrounding non-contaminated areas in China. Neither significant reduction in genetic diversity nor apparent founder and bottleneck effects were observed in metallicolous populations of C. communis. Based on Bayesian and Neighbor-Joining clustering analyses and a principal coordinates analysis, all sampled populations were found to be mainly separated into three genetic groups, corresponding well to their geographical locations rather than edaphic origins. Moreover, a significant and strong correlation between population genetic divergence and geographical distance were detected by Mantel test (r = 0.33; P < 0.05) and multiple matrix regression with randomization (MMRR; βD = 0.57, P < 0.01). However, the effect of copper concentration on genetic patterns of C. communis was not significant (MMRR; βE = -0.17, P = 0.12). Our study clearly demonstrated that the extreme edaphic conditions in metalliferous areas had limited effects on the genetic variability in C. communis. Geographic distance played a more important role in affecting the genetic structure of C. communis than soil composition did. In C. communis, the geographically disjunctive populations on metalliferous soils had multiple origins and evolved independently from nearby non

  8. Geography Plays a More Important Role than Soil Composition on Structuring Genetic Variation of Pseudometallophyte Commelina communis.

    PubMed

    Li, Jiaokun; Xu, Hui; Song, Yunpeng; Tang, Lulu; Gong, Yanbing; Yu, Runlan; Shen, Li; Wu, Xueling; Liu, Yuandong; Zeng, Weimin

    2016-01-01

    Pseudometallophytes are excellent models to study microevolution and local adaptation to soil pollution, as they can grow both on metalliferous and contrasting non-metalliferous soils. Although, there has been accumulating evidence for the effects of edaphic conditions and geographical isolation on the genetic structure of pesudometallophytes, it is still a difficult problem in evolutionary biology to assess their relative importance. In this study, we investigated the spatial patterns of genetic variability, population differentiation and genetic groups in pseudometallophyte Commelina communis with 12 microsatellite loci. Eight metallicolous and six non-metallicolous populations of C. communis were sampled from cupriferous sites and surrounding non-contaminated areas in China. Neither significant reduction in genetic diversity nor apparent founder and bottleneck effects were observed in metallicolous populations of C. communis. Based on Bayesian and Neighbor-Joining clustering analyses and a principal coordinates analysis, all sampled populations were found to be mainly separated into three genetic groups, corresponding well to their geographical locations rather than edaphic origins. Moreover, a significant and strong correlation between population genetic divergence and geographical distance were detected by Mantel test (r = 0.33; P < 0.05) and multiple matrix regression with randomization (MMRR; βD = 0.57, P < 0.01). However, the effect of copper concentration on genetic patterns of C. communis was not significant (MMRR; βE = -0.17, P = 0.12). Our study clearly demonstrated that the extreme edaphic conditions in metalliferous areas had limited effects on the genetic variability in C. communis. Geographic distance played a more important role in affecting the genetic structure of C. communis than soil composition did. In C. communis, the geographically disjunctive populations on metalliferous soils had multiple origins and evolved independently from nearby non

  9. Notch and Wnt/β-catenin signaling pathway play important roles in activating liver cancer stem cells.

    PubMed

    Wang, Ronghua; Sun, Qian; Wang, Peng; Liu, Man; Xiong, Si; Luo, Jing; Huang, Hai; Du, Qiang; Geller, David A; Cheng, Bin

    2016-02-02

    Human hepatocellular carcinoma (HCC) is driven and maintained by liver cancer stem cells (LCSCs) that display stem cell properties. These LCSCs are promoted by the intersecting of Notch and Wnt/β-Catenin signaling pathways. In this study, we demonstrate that LCSCs with markers CD90, CD24, CD13, and CD133 possess stem properties of self-renewal and tumorigenicity in NOD/SCID mice. The increased expression of these markers was correlated with advanced disease stage, larger tumors, and worse overall survival in 61 HCC cases. We also found that both Notch and Wnt/β-catenin signaling pathways played important roles in increasing the stem-ness characteristics of LCSCs. Our data suggested that Notch1 was downstream of Wnt/β-catenin. The active form of Notch1 intracellular domain (NICD) expression depended on Wnt/β-catenin pathway activation. Moreover, Notch1 negatively contributed to Wnt/β-catenin signaling modulation. Knock down of Notch1 with lentivirus N1ShRNA up-regulated the active form of β-catenin. Ectopic expression of NICD with LV-Notch1 in LCSCs attenuated β-catenin/TCF dependent luciferase activity significantly. In addition, there was a non-proteasome mediated feedback loop between Notch1 and Wnt/β-catenin signaling in LCSCs. The central role of Notch and the Wnt/β-catenin signaling pathway in LCSCs may provide an attractive therapeutic strategy against HCC.

  10. Does arsenic play an important role in the soil microbial community around a typical arsenic mining area?

    PubMed

    Wu, Fan; Wang, Jun-Tao; Yang, Jun; Li, Jing; Zheng, Yuan-Ming

    2016-06-01

    Arsenic (As) can cause serious hazards to human health, especially in mining areas. Soil bacterial communities, which are critical parts of the soil ecosystem, were analyzed directly for soil environmental factors. As a consequence, it is of great significance to understand the ecological risk of arsenic contamination on bacteria, especially at the local scale. In this study, 33 pairs of soil and grain samples were collected from the corn and paddy fields around an arsenic mining area in Shimen County in Hunan Province, China. Significant differences were found between the soil nitrogen, As concentrations, and bacteria activities among these two types of land use. According to the structural equation model (SEM) analysis, compared with other environmental factors, soil As was not the key factor affecting the bacterial community, even when grain As was beyond the threshold of the national food hygiene standards of China. In the corn field, soil pH was the main factor dominating the bacterial richness, composition and grain As. Meanwhile, in the paddy field the soil total nitrogen (TN) and total carbon (TC) were the main factors impacting the bacterial richness, and the bacterial community composition was mainly affected by pH. The interactions between grain As and soil As were weak in the corn field. The bacterial communities played important roles in the food chain risk of As. The local policy of transforming paddy soil to dry land could greatly reduce the health risk of As through the food chain.

  11. Discovering the Importance of Play through Personal Histories and Brain Images: An Interview with Stuart L. Brown

    ERIC Educational Resources Information Center

    American Journal of Play, 2009

    2009-01-01

    Stuart L. Brown is founder of the National Institute for Play, a California-based, not-for-profit organization dedicated to the notion that play can help transform the lives of individuals, families, schools, and organizations. Trained in general and internal medicine, psychiatry, and clinical research, Brown was a physician in the United States…

  12. Cyclooxygenase (COX)-1 and COX-2 both play an important role in the protection of the duodenal mucosa in cats.

    PubMed

    Satoh, Hiroshi; Amagase, Kikuko; Ebara, Satomi; Akiba, Yasutada; Takeuchi, Koji

    2013-01-01

    Although nonsteroidal anti-inflammatory drugs often cause ulcers in the duodenum in humans, the role of cyclooxygenase (COX) isoforms in the pathogenesis of duodenal ulcers has not been fully elucidated. We examined in cats the 1) ulcerogenic effects of selective COX-1 (SC-560, ketorolac) and COX-2 (celecoxib, meloxicam) inhibitors on the gastrointestinal mucosa, 2) effect of feeding and cimetidine on the expression of COX isoforms and prostaglandin E(2) (PGE(2)) level in the duodenum, and 3) localization of COX isoforms in the duodenum. COX inhibitors were administered after the morning meal in cats once daily for 3 days. Gastrointestinal lesions were examined on day 4. Localization and expression of COX isoforms (by immunohistochemistry, Western blot) and PGE(2) level (by enzyme immunoassay) were examined. Results were as follows. First, selective COX-1 or COX-2 inhibitors alone produced marked ulcers in the duodenum but did not cause obvious lesions in the small intestine. Coadministration of SC-560 and celecoxib produced marked lesions in the small intestine. Second, feeding increased both the expression of COX isoforms and PGE(2) level in the duodenum, and the effects were markedly inhibited by pretreatment with cimetidine. Third, COX-1 was localized in goblet and Brunner's gland cells, Meissner's and Auerbach's plexus, smooth muscle cells, and arterioles; and COX-2 was observed in capillaries, venules, and basal granulated cells. The expression of COX isoforms in the duodenum is up-regulated by feeding, and inhibition of either COX-1 or COX-2 causes ulcers in the duodenum, suggesting that both isoforms play an important role in the protection of the duodenal mucosa.

  13. Arabidopsis RAP2.2 plays an important role in plant resistance to Botrytis cinerea and ethylene responses.

    PubMed

    Zhao, Yang; Wei, Tong; Yin, Kang-Quan; Chen, Zhangliang; Gu, Hongya; Qu, Li-Jia; Qin, Genji

    2012-07-01

    • Ethylene plays a crucial role in plant resistance to necrotrophic pathogens, in which ETHYLENE RESPONSE FACTORs (ERFs) are often involved. • Here, we evaluated the role of an ERF transcription factor, RELATED TO AP2 2 (RAP2.2), in Botrytis resistance and ethylene responses in Arabidopsis. We analyzed the resistance of transgenic plants overexpressing RAP2.2 and the T-DNA insertion mutant to Botrytis cinerea. We assessed its role in the ethylene signaling pathway by molecular and genetic approaches. • RAP2.2-overexpressing transgenic plants showed increased resistance to B. cinerea, whereas its T-DNA insertion mutant rap2.2-3 showed decreased resistance. Overexpression of RAP2.2 in ethylene insensitive 2 (ein2) and ein3 ein3-like 1 (eil1) mutants restored their resistance to B. cinerea. Both ethylene and Botrytis infection induced the expression of RAP2.2 and the induction was disrupted in ein2 and ein3 eil1 mutants. We identified rap2.12-1 as a T-DNA insertion mutant of RAP2.12, the closest homolog of RAP2.2. The hypocotyls of rap2.2-3 rap2.12-1 double mutants showed ethylene insensitivity. The constitutive triple response in constitutive triple response1 (ctr1) was partially released in the rap2.2-3 rap2.12-1 ctr1 triple mutants. • Our findings demonstrate that RAP2.2 functions as an important regulator in Botrytis resistance and ethylene responses.

  14. Transcription Factor Sp1 Plays an Important Role in the Regulation of Copper Homeostasis in Mammalian Cells

    PubMed Central

    Song, Im-Sook; Chen, Helen H. W.; Aiba, Isamu; Hossain, Anwar; Liang, Zheng D.; Klomp, Leo W. J.; Kuo, Macus Tien

    2008-01-01

    Copper is an essential metal nutrient, yet Cu overload is toxic. Here, we report that human copper transporter 1 (hCtr1) plays an important role in the maintenance of Cu homeostasis by demonstrating that expression of hCtr1 mRNA was up-regulated under Cu-depleted conditions and down-regulated under Cu-replete conditions. Overexpression of full-length hCtr1 by transfection with a recombinant hCtr1 cDNA clone reduced endogenous hCtr1 mRNA levels, whereas overexpression of N-terminus-deleted hCtr1 did not change endogenous hCtr1 mRNA levels, suggesting that increased functional hCtr1 transporter, which leads to increased intracellular Cu contents down-regulates the endogenous hCtr1 mRNA. A luciferase assay using reporter constructs containing the hCtr1 promoter sequences revealed that three Sp1-binding sites are involved in the basal and Cu concentration-dependent regulation of hCtr1 expression. Modulation of Sp1 levels affected the expression of hCtr1. We further demonstrated that zinc finger domain of Sp1 functions as a sensor of Cu that regulates hCtr1 up-and-down in response to Cu concentration variations. Our results demonstrate that mammalian Cu homeostasis is maintained at the hCtr1 mRNA level which is regulated by the Sp1 transcription factor. PMID:18483225

  15. Can Brazil play a more important role in global tuberculosis drug production? An assessment of current capacity and challenges

    PubMed Central

    2013-01-01

    Background Despite the existence of effective treatment, tuberculosis is still a global public health issue. The World Health Organization recommends a six-month four-drug regimen in fixed-dose combination formulation to treat drug sensitive tuberculosis, and long course regimens with several second-line drugs to treat multi-drug resistant tuberculosis. To achieve the projected tuberculosis elimination goal by 2050, it will be essential to ensure a non-interrupted supply of quality-assured tuberculosis drugs. However, quality and affordable tuberculosis drug supply is still a significant challenge for National Tuberculosis Programs. Discussion Quality drug production requires a combination of complex steps. The first challenge is to guarantee the quality of tuberculosis active pharmaceutical ingredients, then ensure an adequate manufacturing process, according to international standards, to guarantee final product´s safety, efficacy and quality. Good practices for storage, transport, distribution and quality control procedures must follow. In contrast to other high-burden countries, Brazil produces tuberculosis drugs through a strong network of public sector drug manufacturers regulated by a World Health Organization-certified national sanitary authority. The installed capacity for production surpasses the 71,000 needed treatments in the country. However, in order to be prepared to act as a global supplier, important bottlenecks are to be overcome. This article presents an in-depth analysis of the current status of production of tuberculosis drugs in Brazil and the bottlenecks and opportunities for the country to sustain national demand and play a role as a potential global supplier. Raw material and drug production, quality control, international certification and pre-qualification, political commitment and regulatory aspects are discussed, as well recommendations for tackling these bottlenecks. This discussion becomes more important as new drugs and regimens to

  16. The SmpB-tmRNA tagging system plays important roles in Streptomyces coelicolor growth and development.

    PubMed

    Yang, Chunzhong; Glover, John R

    2009-01-01

    The ssrA gene encodes tmRNA that, together with a specialized tmRNA-binding protein, SmpB, forms part of a ribonucleoprotein complex, provides a template for the resumption of translation elongation, subsequent termination and recycling of stalled ribosomes. In addition, the mRNA-like domain of tmRNA encodes a peptide that tags polypeptides derived from stalled ribosomes for degradation. Streptomyces are unique bacteria that undergo a developmental cycle culminating at sporulation that is at least partly controlled at the level of translation elongation by the abundance of a rare tRNA that decodes UUA codons found in a relatively small number of open reading frames prompting us to examine the role of tmRNA in S. coelicolor. Using a temperature sensitive replicon, we found that the ssrA gene could be disrupted only in cells with an extra-copy wild type gene but not in wild type cells or cells with an extra-copy mutant tmRNA (tmRNA(DD)) encoding a degradation-resistant tag. A cosmid-based gene replacement method that does not include a high temperature step enabled us to disrupt both the ssrA and smpB genes separately and at the same time suggesting that the tmRNA tagging system may be required for cell survival under high temperature. Indeed, mutant cells show growth and sporulation defects at high temperature and under optimal culture conditions. Interestingly, even though these defects can be completely restored by wild type genes, the DeltassrA strain was only partially corrected by tmRNA(DD). In addition, wildtype tmRNA can restore the hygromycin-resistance to DeltassrA cells while tmRNA(DD) failed to do so suggesting that degradation of aberrant peptides is important for antibiotic resistance. Overall, these results suggest that the tmRNA tagging system plays important roles during Streptomyces growth and sporulation under both normal and stress conditions.

  17. The SmpB-tmRNA Tagging System Plays Important Roles in Streptomyces coelicolor Growth and Development

    PubMed Central

    Yang, Chunzhong; Glover, John R.

    2009-01-01

    The ssrA gene encodes tmRNA that, together with a specialized tmRNA-binding protein, SmpB, forms part of a ribonucleoprotein complex, provides a template for the resumption of translation elongation, subsequent termination and recycling of stalled ribosomes. In addition, the mRNA-like domain of tmRNA encodes a peptide that tags polypeptides derived from stalled ribosomes for degradation. Streptomyces are unique bacteria that undergo a developmental cycle culminating at sporulation that is at least partly controlled at the level of translation elongation by the abundance of a rare tRNA that decodes UUA codons found in a relatively small number of open reading frames prompting us to examine the role of tmRNA in S. coelicolor. Using a temperature sensitive replicon, we found that the ssrA gene could be disrupted only in cells with an extra-copy wild type gene but not in wild type cells or cells with an extra-copy mutant tmRNA (tmRNADD) encoding a degradation-resistant tag. A cosmid-based gene replacement method that does not include a high temperature step enabled us to disrupt both the ssrA and smpB genes separately and at the same time suggesting that the tmRNA tagging system may be required for cell survival under high temperature. Indeed, mutant cells show growth and sporulation defects at high temperature and under optimal culture conditions. Interestingly, even though these defects can be completely restored by wild type genes, the ΔssrA strain was only partially corrected by tmRNADD. In addition, wildtype tmRNA can restore the hygromycin-resistance to ΔssrA cells while tmRNADD failed to do so suggesting that degradation of aberrant peptides is important for antibiotic resistance. Overall, these results suggest that the tmRNA tagging system plays important roles during Streptomyces growth and sporulation under both normal and stress conditions. PMID:19212432

  18. Monomethyl Branched-Chain Fatty Acids Play an Essential Role in Caenorhabditis elegans Development

    PubMed Central

    Crawford, Quinn T; Seiber, Matt; Wang, Cun-Yu

    2004-01-01

    Monomethyl branched-chain fatty acids (mmBCFAs) are commonly found in many organisms from bacteria to mammals. In humans, they have been detected in skin, brain, blood, and cancer cells. Despite a broad distribution, mmBCFAs remain exotic in eukaryotes, where their origin and physiological roles are not understood. Here we report our study of the function and regulation of mmBCFAs in Caenorhabditis elegans, combining genetics, gas chromatography, and DNA microarray analysis. We show that C. elegans synthesizes mmBCFAs de novo and utilizes the long-chain fatty acid elongation enzymes ELO-5 and ELO-6 to produce two mmBCFAs, C15ISO and C17ISO. These mmBCFAs are essential for C. elegans growth and development, as suppression of their biosynthesis results in a growth arrest at the first larval stage. The arrest is reversible and can be overcome by feeding the arrested animals with mmBCFA supplements. We show not only that the levels of C15ISO and C17ISO affect the expression of several genes, but also that the activities of some of these genes affect biosynthesis of mmBCFAs, suggesting a potential feedback regulation. One of the genes, lpd-1, encodes a homolog of a mammalian sterol regulatory element-binding protein (SREBP 1c). We present results suggesting that elo-5 and elo-6 may be transcriptional targets of LPD-1. This study exposes unexpected and crucial physiological functions of C15ISO and C17ISO in C. elegans and suggests a potentially important role for mmBCFAs in other eukaryotes. PMID:15340492

  19. Triterpenoid Acids as Important Antiproliferative Constituents of European Elderberry Fruits.

    PubMed

    Gleńsk, Michał; Czapińska, Elżbieta; Woźniak, Marta; Ceremuga, Ireneusz; Włodarczyk, Maciej; Terlecki, Grzegorz; Ziółkowski, Piotr; Seweryn, Ewa

    2017-03-21

    In Europe, both the fruits and flowers of Sambucus nigra L. have been used against cold, as well as laxative, diaphoretic, and diuretic remedies. There are also a number of commercially available food products that contain elderberry juice, puréed or dried elderberries. Recent comprehensive literature data on pharmacology and chemistry of Sambuci fructus have encouraged us to screen extracts with different polarities from this plant material against cancer cell lines. The cytotoxic activity of the ethyl acetate and aqueous acetone extracts from elderberries as well as detected triterpenoids on human colon adenocarcinoma cell line (LoVo) and human breast cancer cell line (MCF-7) was investigated by sulforhodamine B assay. Moreover, cell migration assay was conducted for triterpenoid fraction and pure compounds. Aqueous acetone extract possessed much lower IC50 value in cancer cell lines compared to ethyl acetate extract. The latter manifested high cytotoxicity against studied cell lines, suggesting that nonpolar compounds are responsible for the cytotoxic activity. Indeed, the phytochemical analysis revealed that ursolic and oleanolic acids are the main triterpenoids in the mentioned extract of which ursolic acid showed the highest activity with IC50 values of 10.7 µg/mL on MCF-7 and 7.7 µg/mL on LoVo cells.

  20. LYZL6, an acidic, bacteriolytic, human sperm-related protein, plays a role in fertilization

    PubMed Central

    Huang, Peng; Li, Wenshu; Yang, Zhifang; Zhang, Ning; Xu, Yixin; Bao, Jianying; Jiang, Deke; Dong, Xianping

    2017-01-01

    Lysozyme-like proteins (LYZLs) belong to the c-type lysozyme/α-lactalbumin family and are selectively expressed in the mammalian male reproductive tract. Two members, human sperm lysozyme-like protein (SLLP) -1 and mouse LYZL4, have been reported to contribute to fertilization but show no bacteriolytic activity. Here, we focused on the possible contribution of LYZL6 to immunity and fertilization. In humans, LYZL6 was selectively expressed by the testis and epididymis and became concentrated on spermatozoa. Native LYZL6 isolated from sperm extracts exhibited bacteriolytic activity against Micrococcus lysodeikticus. Recombinant LYZL6 (rLYZL6) reached its peak activity at pH 5.6 and 15 mM of Na+, and could inhibit the growth of Gram-positive, but not Gram-negative bacteria. Nevertheless, the bacteriolytic activity of rLYZL6 proved to be much lower than that of human lysozyme under physiological conditions. Immunodetection with a specific antiserum localized the LYZL6 protein on the postacrosomal membrane of mature spermatozoa. Immunoneutralization of LYZL6 significantly decreased the numbers of human spermatozoa fused with zona-free hamster eggs in a dose-dependent manner in vitro. Thus, we report here for the first time that LYZL6, an acidic, bacteriolytic and human sperm-related protein, is likely important for fertilization but not for the innate immunity of the male reproductive tract. PMID:28182716

  1. Ursolic acid plays a role in Nepeta sibthorpii Bentham CNS depressing effects.

    PubMed

    Taviano, M F; Miceli, N; Monforte, M T; Tzakou, O; Galati, E M

    2007-04-01

    The sedative, anticonvulsant and analgesic activity of ursolic acid, a terpenoid bioassay-isolated from Nepeta sibthorpii Bentham, was evaluated in mice. The oral administration of ursolic acid (2.3 mg/kg) produced a significant depressant effect on CNS by reducing spontaneous motor activity and the number and lethality of pentylenetetrazol (PTZ)-induced seizures. Two models of nociception, the writhing test and the hot plate test, were also used to examine the analgesic effect of ursolic acid. At a dose of 2.3 mg/kg, ursolic acid caused an inhibition of acetic acid-induced abdominal constriction, but was inactive in the hot plate test. Treatment at a higher dose (20 mg/kg) significantly increased the reaction time in the hot plate test. This effect, reversed by naloxone, evidently involves opioid receptors, but the analgesic activity of ursolic acid may be related also to the antiinflammatory and antioxidant properties of this compound.

  2. The Saccharomyces Cerevisiae Spt7 Gene Encodes a Very Acidic Protein Important for Transcription in Vivo

    PubMed Central

    Gansheroff, L. J.; Dollard, C.; Tan, P.; Winston, F.

    1995-01-01

    Mutations in the SPT7 gene of Saccharomyces cerevisiae originally were identified as suppressors of Ty and {delta small} insertion mutations in the 5' regions of the HIS4 and LYS2 genes. Other genes that have been identified in mutant hunts of this type have been shown to play a role in transcription. In this work we show that SPT7 is also important for proper transcription in vivo. We have cloned and sequenced the SPT7 gene and have shown that it encodes a large, acidic protein that is localized to the nucleus. The SPT7 protein contains a bromodomain sequence; a deletion that removes the bromodomain from the SPT7 protein causes no detectable mutant phenotype. Strains that contain an spt7 null mutation are viable but grow very slowly and have transcriptional defects at many loci including insertion mutations, Ty elements, the INO1 gene and the MFA1 gene. These transcriptional defects and other mutant phenotypes are similar to those caused by certain mutations in SPT15, which encodes the TATA binding protein (TBP). The similarity of the phenotypes of spt7 and spt15 mutants, including effects of spt7 mutations on the transcription start site of certain genes, suggests that SPT7 plays an important role in transcription initiation in vivo. PMID:7713415

  3. Caveolin-1 plays a key role in the oleanolic acid-induced apoptosis of HL-60 cells.

    PubMed

    Ma, Wei; Wang, Di-Di; Li, Li; Feng, Yu-Kuan; Gu, Hong-Mei; Zhu, Gui-Ming; Piao, Jin-Hua; Yang, Yu; Gao, Xu; Zhang, Peng-Xia

    2014-07-01

    Our previous study found that caveolin-1 (CAV-1) protein expression is upregulated during oleanolic acid (OA)-induced inhibition of proliferation and promotion of apoptosis in HL-60 cells. CAV-1 is the main structural protein component of caveolae, playing important roles in tumorigenesis and tumor development. It has been shown that cav-1 expression is lower in leukemia cancer cell lines SUP-B15, HL-60, THP-1 and K562 and in chronic lymphocytic leukemia primary (CLP) cells when compared with normal white blood cells, with the lowest cav-1 expression level found in HL-60 cells. To study the effects of cav-1 in HL-60 cells and the effects of cav-1 overexpression on OA drug efficacy, cav-1 was overexpressed in HL-60 cells using lentiviral-mediated transfection combined with OA treatment. The results showed that cav-1 overexpression inhibited HL-60 cell proliferation, promoted apoptosis, arrested the cell cycle in the G1 phase and inhibited activation of the PI3K/AKT/mTOR signaling pathway. Overexpression of CAV-1 also increased HL-60 cell sensitivity to OA. To further verify whether OA affects HL-60 cells via the activation of downstream signaling pathways by CAV-1, cav-1 gene expression was silenced using RNAi, and the cells were treated with OA to examine its efficacy. The results showed that after cav-1 silencing, OA had little effect on cell activity, apoptosis, the cell cycle and phosphorylation of HL-60 cells. This study is the first to show that CAV-1 plays a crucial role in the effects of OA on HL-60 cells.

  4. Intra-myocellular fatty acid metabolism plays a critical role in mediating responses to dietary restriction in Drosophila melanogaster

    PubMed Central

    Katewa, Subhash D.; Demontis, Fabio; Kolipinski, Marysia; Hubbard, Allan; Gill, Matthew S.; Perrimon, Norbert; Melov, Simon; Kapahi, Pankaj

    2012-01-01

    Summary Changes in fat content have been associated with dietary restriction (DR), but whether they play a causal role in mediating various responses to DR remains unknown. We demonstrate that upon DR, Drosophila melanogaster shift their metabolism towards increasing both fatty acid synthesis and breakdown, which is required for various responses to DR. Inhibition of fatty acid synthesis or oxidation genes specifically in the muscle tissue inhibited lifespan extension upon DR. Furthermore, DR enhances spontaneous activity of flies which was found to be dependent on the enhanced fatty acid metabolism. This increase in activity was found to be at least partially required for the lifespan extension upon DR. Over-expression of adipokinetic hormone (dAKH), the functional ortholog of glucagon, enhances fat metabolism, spontaneous activity and lifespan. Together, these results suggest that enhanced fat metabolism in the muscle and physical activity play a key role in the protective effects of DR. PMID:22768842

  5. Butyrate and deoxycholic acid play common and distinct roles in HCT116 human colon cell proliferation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of a high fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer preventive effects. To distinguish these opposing effects of D...

  6. Butyrate and deoxycholic acid play common and distinct roles in HCT116 human colon cell proliferation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Consumption of a high fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer preventive effects. To distinguish these opposing effects of DCA and...

  7. A petunia homeodomain-leucine zipper protein, PhHD-Zip, plays an important role in flower senescence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flower senescence is mediated in part by changes of plant hormones, such as ethylene, cytokinin and abscisic acid (ABA). Ethylene is known to control flower senescence in many species, especially ethylene sensitive flowers, like petunia, carnation and rose. During flower senescence in petunia and ot...

  8. Repression of ARF10 by microRNA160 plays an important role in the mediation of leaf water loss.

    PubMed

    Liu, Xin; Dong, Xiufen; Liu, Zihan; Shi, Zihang; Jiang, Yun; Qi, Mingfang; Xu, Tao; Li, Tianlai

    2016-10-01

    Solanum lycopersicum auxin response factor 10 (SlARF10) is post-transcriptionally regulated by Sl-miR160. Overexpression of a Sl-miR160-resistant SlARF10 (mSlARF10) resulted in narrower leaflet blades with larger stomata but lower densities. 35S:mSlARF10-6 plants with narrower excised leaves had greater water loss, which was in contrast to the wild type (WT). Further analysis revealed that the actual water loss was not consistent with the calculated stomatal water loss in 35S:mSlARF10-6 and the WT under the dehydration treatment, indicating that there is a difference in hydraulic conductance. Pretreatment with abscisic acid (ABA) and HgCl2 confirmed higher hydraulic conductance in 35S:mSlARF10, which is related to the larger stomatal size and higher activity of aquaporins (AQPs). Under ABA treatment, 35S:mSlARF10-6 showed greater sensitivity, and the stomata closed rapidly. Screening by RNA sequencing revealed that five AQP-related genes, fourteen ABA biosynthesis/signal genes and three stomatal development genes were significantly altered in 35S:mSlARF10-6 plants, and this result was verified by qRT-PCR. The promoter analysis showed that upregulated AQPs contain AuxRE and ABRE, implying that these elements may be responsible for the high expression levels of AQPs in 35S:mSlARF10-6. The three most upregulated AQPs (SlTIP1-1-like, SlPIP2;4 and SlNIP-type-like) were chosen to confirm AuxRE and ABRE function. Promoters transient expression demonstrated that the SlPIP2;4 and SlNIP-type-like AuxREs and SlPIP2;4 and SlTIP1-1-like ABREs could significantly enhance the expression of the GUS reporter in 35S:mSlARF10-6, confirming that AuxRE and ABRE may be the main factors inducing the expression of AQPs. Additionally, two upregulated transcription factors in 35S:mSlARF10-6, SlARF10 and SlABI5-like were shown to directly bind to those elements in an electromobility shift assay and a yeast one-hybrid assay. Furthermore, transient expression of down-regulated ARF10 or up

  9. H2O2 plays an important role in the lifestyle of Colletotrichum gloeosporioides during interaction with cowpea [Vigna unguiculata (L.) Walp].

    PubMed

    Eloy, Ygor R G; Vasconcelos, Ilka M; Barreto, Ana L H; Freire-Filho, Francisco R; Oliveira, Jose T A

    2015-08-01

    Plant-fungus interactions usually generate H(2)O(2) in the infected plant tissue. H(2)O(2) has a direct antimicrobial effect and is involved in the cross-linking of cell walls, signaling, induction of gene expression, hypersensitive cell death and induced systemic acquired resistance. This has raised the hypothesis that H(2)O(2) manipulation by pharmacological compounds could alter the lifestyle of Colletotrichum gloeosporioides during interaction with the BR-3-Tracuateua cowpea genotype. The primary leaves of cowpea were excised, infiltrated with salicylic acid (SA), glucose oxidase + glucose (GO/G), catalase (CAT) or diphenyliodonium chloride (DPI), followed by spore inoculation on the adaxial leaf surface. SA or GO/G-treated plantlets showed increased H(2)O(2) accumulation and lipid peroxidation. The fungus used a subcuticular, intramural necrotrophic strategy, and developed secondary hyphae associated with the quick spread and rapid killing of host cells. However, CAT or DPI-treated leaves exhibited decreased H(2)O(2) concentration and lipid peroxidation and the fungus developed intracellular hemibiotrophic infection with vesicles, in addition to primary and secondary hyphal formation. These results suggest that H(2)O(2) plays an important role in the cowpea (C. gloeosporioides) pathosystem given that it affected fungal lifestyle during interaction.

  10. Metabolic engineering of Pichia pastoris to produce ricinoleic acid, a hydroxy fatty acid of industrial importance.

    PubMed

    Meesapyodsuk, Dauenpen; Chen, Yan; Ng, Siew Hon; Chen, Jianan; Qiu, Xiao

    2015-11-01

    Ricinoleic acid (12-hydroxyoctadec-cis-9-enoic acid) has many specialized uses in bioproduct industries, while castor bean is currently the only commercial source for the fatty acid. This report describes metabolic engineering of a microbial system (Pichia pastoris) to produce ricinoleic acid using a "push" (synthesis) and "pull" (assembly) strategy. CpFAH, a fatty acid hydroxylase from Claviceps purpurea, was used for synthesis of ricinoleic acid, and CpDGAT1, a diacylglycerol acyl transferase for the triacylglycerol synthesis from the same species, was used for assembly of the fatty acid. Coexpression of CpFAH and CpDGAT1 produced higher lipid contents and ricinoleic acid levels than expression of CpFAH alone. Coexpression in a mutant haploid strain defective in the Δ12 desaturase activity resulted in a higher level of ricinoleic acid than that in the diploid strain. Intriguingly, the ricinoleic acid produced was mainly distributed in the neutral lipid fractions, particularly the free fatty acid form, but with little in the polar lipids. This work demonstrates the effectiveness of the metabolic engineering strategy and excellent capacity of the microbial system for production of ricinoleic acid as an alternative to plant sources for industrial uses.

  11. Toxicity of formic acid against red imported fire ants, Solenopsis invicta Buren

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Formic acid is a common defensive chemical of formicine ants. Ants often compete with other ants for resources. However, the toxicity of formic acid to any ant species has not been well understood. This study examined the toxicity of formic acid against the red imported fire ants, Sole...

  12. A Putative Mitochondrial Iron Transporter MrsA in Aspergillus fumigatus Plays Important Roles in Azole-, Oxidative Stress Responses and Virulence.

    PubMed

    Long, Nanbiao; Xu, Xiaoling; Qian, Hui; Zhang, Shizhu; Lu, Ling

    2016-01-01

    Iron is an essential nutrient and enzyme co-factor required for a wide range of cellular processes, especially for the function of mitochondria. For the opportunistic fungal pathogen Aspergillus fumigatus, the ability to obtain iron is required for growth and virulence during the infection process. However, knowledge of how mitochondria are involved in iron regulation is still limited. Here, we show that a mitochondrial iron transporter, MrsA, a homolog of yeast Mrs4p, is critical for adaptation to iron-limited or iron-excess conditions in A. fumigatus. Deletion of mrsA leads to disruption of iron homeostasis with a decreased sreA expression, resulted in activated reductive iron assimilation (RIA) and siderophore-mediated iron acquisition (SIA). Furthermore, deletion of mrsA induces hypersusceptibility to azole and oxidative stresses. An assay for cellular ROS content in ΔmrsA combined with rescue from the mrsA-defective phenotype by the antioxidant reagent L-ascorbic acid indicates that the increased sensitivity of ΔmrsA to the azole itraconazole and to oxidative stress is mainly the result of abnormal ROS accumulation. Moreover, site-directed mutation experiments verified that three conserved histidine residues related to iron transport in MrsA are required for responses to oxidative and azole stresses. Importantly, ΔmrsA causes significant attenuation of virulence in an immunocompromised murine model of aspergillosis. Collectively, our results show that the putative mitochondrial iron transporter MrsA plays important roles in azole- and oxidative-stress responses and virulence by regulating the balance of cellular iron in A. fumigatus.

  13. A Putative Mitochondrial Iron Transporter MrsA in Aspergillus fumigatus Plays Important Roles in Azole-, Oxidative Stress Responses and Virulence

    PubMed Central

    Long, Nanbiao; Xu, Xiaoling; Qian, Hui; Zhang, Shizhu; Lu, Ling

    2016-01-01

    Iron is an essential nutrient and enzyme co-factor required for a wide range of cellular processes, especially for the function of mitochondria. For the opportunistic fungal pathogen Aspergillus fumigatus, the ability to obtain iron is required for growth and virulence during the infection process. However, knowledge of how mitochondria are involved in iron regulation is still limited. Here, we show that a mitochondrial iron transporter, MrsA, a homolog of yeast Mrs4p, is critical for adaptation to iron-limited or iron-excess conditions in A. fumigatus. Deletion of mrsA leads to disruption of iron homeostasis with a decreased sreA expression, resulted in activated reductive iron assimilation (RIA) and siderophore-mediated iron acquisition (SIA). Furthermore, deletion of mrsA induces hypersusceptibility to azole and oxidative stresses. An assay for cellular ROS content in ΔmrsA combined with rescue from the mrsA-defective phenotype by the antioxidant reagent L-ascorbic acid indicates that the increased sensitivity of ΔmrsA to the azole itraconazole and to oxidative stress is mainly the result of abnormal ROS accumulation. Moreover, site-directed mutation experiments verified that three conserved histidine residues related to iron transport in MrsA are required for responses to oxidative and azole stresses. Importantly, ΔmrsA causes significant attenuation of virulence in an immunocompromised murine model of aspergillosis. Collectively, our results show that the putative mitochondrial iron transporter MrsA plays important roles in azole- and oxidative-stress responses and virulence by regulating the balance of cellular iron in A. fumigatus. PMID:27433157

  14. Cold shock protein A plays an important role in the stress adaptation and virulence of Brucella melitensis.

    PubMed

    Wang, Zhen; Wang, Shuangshan; Wu, Qingmin

    2014-05-01

    Brucella melitensis is a facultative intracellular pathogen that mainly resides within macrophages. The mechanisms employed by Brucella to adapt to harsh intracellular environments and survive within host macrophages are not clearly understood. Here, we constructed a cspA gene deletion mutant, NIΔcspA, that did not exhibit any discernible growth defect at a normal culture temperature (37 °C) or at a low temperature (15 °C). However, expression of the cspA gene in Brucella was induced by cold, acidic, and oxidative conditions, as determined via quantitative reverse transcription PCR. Unlike its parental strain, B. melitensis NI, the NIΔcspA mutant showed an increased sensitivity to acidic and H2 O2 stresses, especially during the mid-log-phase, and these stress conditions would presumably be encountered by bacteria during intracellular infections. Moreover, macrophage and mouse infection assays indicated that the NIΔcspA mutant fails to replicate in cultured J774.A1 murine macrophages and is rapidly cleared from the spleens of experimentally infected BALB/c mice. These findings suggest that the Brucella cspA gene makes an essential contribution to virulence in vitro and in vivo, most likely by allowing brucellae to adapt appropriately to the harsh environmental conditions encountered within host macrophages.

  15. mTOR plays an important role in cow's milk allergy-associated behavioral and immunological deficits.

    PubMed

    Wu, Jiangbo; de Theije, Caroline G M; da Silva, Sofia Lopes; van der Horst, Hilma; Reinders, Margot T M; Broersen, Laus M; Willemsen, Linette E M; Kas, Martien J H; Garssen, Johan; Kraneveld, Aletta D

    2015-10-01

    Autism spectrum disorder (ASD) is multifactorial, with both genetic as well as environmental factors working in concert to develop the autistic phenotype. Immunological disturbances in autistic individuals have been reported and a role for food allergy has been suggested in ASD. Single gene mutations in mammalian target of rapamycin (mTOR) signaling pathway are associated with the development of ASD and enhanced mTOR signaling plays a central role in directing immune responses towards allergy as well. Therefore, the mTOR pathway may be a pivotal link between the immune disturbances and behavioral deficits observed in ASD. In this study it was investigated whether the mTOR pathway plays a role in food allergy-induced behavioral and immunological deficits. Mice were orally sensitized and challenged with whey protein. Meanwhile, cow's milk allergic (CMA) mice received daily treatment of rapamycin. The validity of the CMA model was confirmed by showing increased allergic immune responses. CMA mice showed reduced social interaction and increased repetitive self-grooming behavior. Enhanced mTORC1 activity was found in the brain and ileum of CMA mice. Inhibition of mTORC1 activity by rapamycin improved the behavioral and immunological deficits of CMA mice. This effect was associated with increase of Treg associated transcription factors in the ileum of CMA mice. These findings indicate that mTOR activation may be central to both the intestinal, immunological, and psychiatric ASD-like symptoms seen in CMA mice. It remains to be investigated whether mTOR can be seen as a therapeutic target in cow's milk allergic children suffering from ASD-like symptoms.

  16. G-protein-coupled bile acid receptor plays a key role in bile acid metabolism and fasting-induced hepatic steatosis in mice.

    PubMed

    Donepudi, Ajay C; Boehme, Shannon; Li, Feng; Chiang, John Y L

    2017-03-01

    Bile acids are signaling molecules that play a critical role in regulation of hepatic metabolic homeostasis by activating nuclear farnesoid X receptor (Fxr) and membrane G-protein-coupled receptor (Takeda G-protein-coupled receptor 5; Tgr5). The role of FXR in regulation of bile acid synthesis and hepatic metabolism has been studied extensively. However, the role of TGR5 in hepatic metabolism has not been explored. The liver plays a central role in lipid metabolism, and impaired response to fasting and feeding contributes to steatosis and nonalcoholic fatty liver and obesity. We have performed a detailed analysis of gallbladder bile acid and lipid metabolism in Tgr5(-/-) mice in both free-fed and fasted conditions. Lipid profiles of serum, liver and adipose tissues, bile acid composition, energy metabolism, and messenger RNA and protein expression of the genes involved in lipid metabolism were analyzed. Results showed that deficiency of the Tgr5 gene in mice alleviated fasting-induced hepatic lipid accumulation. Expression of liver oxysterol 7α-hydroxylase in the alternative bile acid synthesis pathway was reduced. Analysis of gallbladder bile acid composition showed marked increase of taurocholic acid and decrease of tauro-α and β-muricholic acid in Tgr5(-/-) mice. Tgr5(-/-) mice had increased hepatic fatty acid oxidation rate and decreased hepatic fatty acid uptake. Interestingly, fasting induction of fibroblast growth factor 21 in liver was attenuated. In addition, fasted Tgr5(-/-) mice had increased activation of hepatic growth hormone-signal transducer and activator of transcription 5 (GH-Stat5) signaling compared to wild-type mice.

  17. Mouse ghrelin-O-acyltransferase (GOAT) plays a critical role in bile acid reabsorption.

    PubMed

    Kang, Kihwa; Schmahl, Jennifer; Lee, Jong-Min; Garcia, Karen; Patil, Ketan; Chen, Amelia; Keene, Michelle; Murphy, Andrew; Sleeman, Mark W

    2012-01-01

    Ghrelin is a unique peptide gut hormone that requires post-translational modification to stimulate both feeding and growth hormone release. Ghrelin O-acyltransferase (GOAT) was identified as a specific acyl-transferase for ghrelin, and recent genetic deletion studies of the Goat gene (Goat(-/-)) uncovered the role of ghrelin in the regulation of glucose homeostasis. To further understand the physiological functions of the GOAT/ghrelin system, we have conducted a metabolomic and microarray profile of Goat-null mice, as well as determined Goat expression in different tissues using the lacZ reporter gene. Serum metabolite profile analysis revealed that Goat(-/-) mice exhibited increased secondary bile acids >2.5-fold. This was attributed to increased mRNA and protein expression of the ileal sodium-dependent bile acid transporter (ISBT) in the intestinal and biliary tract. Increased expression of additional solute carrier proteins, including Slc5a12 (>10-fold) were also detected in the small intestine and bile duct. Goat staining was consistently observed in the pituitary glands, stomach, and intestines, and to a lesser extent in the gallbladder and pancreatic duct. This is the first report that the GOAT/ghrelin system regulates bile acid metabolism, and these findings suggest a novel function of GOAT in the regulation of intestinal bile acid reabsorption..

  18. Cell wall properties play an important role in the emergence of lateral root primordia from the parent root.

    PubMed

    Roycewicz, Peter S; Malamy, Jocelyn E

    2014-05-01

    Plants adapt to their unique soil environments by altering the number and placement of lateral roots post-embryonic. Mutants were identified in Arabidopsis thaliana that exhibit increased lateral root formation. Eight mutants were characterized in detail and were found to have increased lateral root formation due to at least three distinct mechanisms. The causal mutation in one of these mutants was found in the XEG113 gene, recently shown to be involved in plant cell wall biosynthesis. Lateral root primordia initiation is unaltered in this mutant. In contrast, synchronization of lateral root initiation demonstrated that mutation of XEG113 increases the rate at which lateral root primordia develop and emerge to form lateral roots. The effect of the XEG113 mutation was specific to the root system and had no apparent effect on shoot growth. Screening of 17 additional cell wall mutants, altering a myriad of cell wall components, revealed that many (but not all) types of cell wall defects promote lateral root formation. These results suggest that proper cell wall biosynthesis is necessary to constrain lateral root primordia emergence. While previous reports have shown that lateral root emergence is accompanied by active remodelling of cell walls overlying the primordia, this study is the first to demonstrate that alteration of the cell wall is sufficient to promote lateral root formation. Therefore, inherent cell wall properties may play a previously unappreciated role in regulation of root system architecture.

  19. The ABA receptor PYL9 together with PYL8 plays an important role in regulating lateral root growth

    PubMed Central

    Xing, Lu; Zhao, Yang; Gao, Jinghui; Xiang, Chengbin; Zhu, Jian-Kang

    2016-01-01

    Abscisic acid is a phytohormone regulating plant growth, development and stress responses. PYR1/PYL/RCAR proteins are ABA receptors that function by inhibiting PP2Cs to activate SnRK2s, resulting in phosphorylation of ABFs and other effectors of ABA response pathways. Exogenous ABA induces growth quiescence of lateral roots, which is prolonged by knockout of the ABA receptor PYL8. Among the 14 members of PYR1/PYL/RCAR protein family, PYL9 is a close relative of PYL8. Here we show that knockout of both PYL9 and PYL8 resulted in a longer ABA-induced quiescence on lateral root growth and a reduced sensitivity to ABA on primary root growth and lateral root formation compared to knockout of PYL8 alone. Induced overexpression of PYL9 promoted the lateral root elongation in the presence of ABA. The prolonged quiescent phase of the pyl8-1pyl9 double mutant was reversed by exogenous IAA. PYL9 may regulate auxin-responsive genes in vivo through direct interaction with MYB77 and MYB44. Thus, PYL9 and PYL8 are both responsible for recovery of lateral root from ABA inhibition via MYB transcription factors. PMID:27256015

  20. Reactive oxygen system plays an important role in shrimp Litopenaeus vannamei defense against Vibrio parahaemolyticus and WSSV infection.

    PubMed

    Ji, Pei-Feng; Yao, Cui-Luan; Wang, Zhi-Yong

    2011-08-29

    The present study investigated the in vivo hemocytic and hepatopancreatic response to Vibrio parahaemolyticus and white spot syndrome virus (WSSV) injection in shrimp Litopenaeus vannamei. The proliferation of bacteria and virus in shrimp, animal mortality, total hemocyte counts (THCs), phenoloxidase (PO) activity, respiratory burst, and gene expression of immune factors associated with immune recognition (lectin), prophenoloxidase (proPO) activation, and the anti-microorganism (lysozyme) and active oxygen defense response (including respiratory burst, cytosolic manganese superoxide dismutase [C-MnSOD], and catalase [CAT]) were quantified. Shrimp death rate increased significantly and was time-dependent after V. parahaemolyticus or WSSV injection. The production of superoxide anion, and the gene expression including lectin in hemocytes, proPO in the hepatopancreas, lysozyme, C-MnSOD and CAT could be induced by injection with V parahaemolyticus and WSSV. The highest value of lysozyme was in the hemocytes with 66.59 times (at 3 h) greater expression than in the control group after WSSV injection and 3.69 times (24 h) greater than in the control group after V parahaemolyticus injection. In the hepatopancreas, CAT expression showed a significant increase, with up to 16 times greater expression than in the control group at 6 h postinjection with WSSV and 7.02 times greater expression than in the control group at 48 h postinjection with V parahaemolyticus (p < 0.05). However, significant decreases in PO activity and proPO transcripts in hemocytes and lectin transcripts in the hepatopancreas were detected after V parahaemolyticus and WSSV injection (p < 0.05). The results suggest that lysozyme, the antioxidase system, and reactive oxygen species might play a crucial role in shrimp defense against bacterial and viral infection.

  1. Carbon nanotubes play an important role in the spatial arrangement of calcium deposits in hydrogels for bone regeneration.

    PubMed

    Cancian, Giulia; Tozzi, Gianluca; Hussain, Amirul Ashraf Bin; De Mori, Arianna; Roldo, Marta

    2016-08-01

    Age related bone diseases such as osteoporosis are considered among the main causes of reduced bone mechanical stability and bone fractures. In order to restore both biological and mechanical function of diseased/fractured bones, novel bioactive scaffolds that mimic the bone structure are constantly under development in tissue engineering applications. Among the possible candidates, chitosan-based thermosensitive hydrogel scaffolds represent ideal systems due to their biocompatibility, biodegradability, enhanced antibacterial properties, promotion of osteoblast formation and ease of injection, which makes them suitable for less invasive surgical procedures. As a main drawback, these chitosan systems present poor mechanical performance that could not support load-bearing applications. In order to produce more mechanically-competent biomaterials, the combined addition of hydroxyapatite and carbon nanotubes (CNTs) is proposed in this study. Specifically, the aim of this work is to develop thermosensitive chitosan hydrogels containing stabilised single-walled and multi-walled CNTs, where their effect on the mechanical/physiochemical properties, calcium deposition patterns and ability to provide a platform for the controlled release of protein drugs was investigated. It was found that the addition of CNTs had a significant effect on the sol-gel transition time and significantly increased the resistance to compression for the hydrogels. Moreover, in vitro calcification studies revealed that CNTs played a major role in the spatial arrangements of newly formed calcium deposits in the composite materials studied, suggesting that they may have a role in the way the repair of fragile and/or fractured bones occurs in vivo.

  2. Tyrosine residues at the carboxyl terminus of Vav1 play an important role in regulation of its biological activity.

    PubMed

    Lazer, Galit; Pe'er, Liron; Farago, Marganit; Machida, Kazuya; Mayer, Bruce J; Katzav, Shulamit

    2010-07-23

    The guanine nucleotide exchange factor (GEF) Vav1 is an essential signal transducer protein in the hematopoietic system, where it is expressed physiologically. It is also involved in several human malignancies. Tyrosine phosphorylation at the Vav1 amino terminus plays a central role in regulating its activity; however, the role of carboxyl terminal tyrosine residues is unknown. We found that mutation of either Tyr-826 (Y826F) or Tyr-841 (Y841F) to phenylalanine led to loss of Vav1 GEF activity. When these Vav1 mutants were ectopically expressed in pancreatic cancer cells lacking Vav1, they failed to induce growth in agar, indicating loss of transforming potential. Furthermore, although Y841F had no effect on Vav1-stimulated nuclear factor of activated T cells (NFAT) activity, Y826F doubled NFAT activity when compared with Vav1, suggesting that Tyr-826 mediates an autoinhibitory effect on NFAT activity. SH2 profiling revealed that Shc, Csk, Abl, and Sap associate with Tyr-826, whereas SH2-B, Src, Brk, GTPase-activating protein, and phospholipase C-gamma associate with Tyr-841. Although the mutations in the Tyr-826 and Tyr-841 did not affect the binding of the carboxyl SH3 of Vav1 to other proteins, binding to several of the proteins identified by the SH2 profiling was lost. Of interest is Csk, which associates with wild-type Vav1 and Y841F, yet it fails to associate with Y826F, suggesting that loss of binding between Y826F and Csk might relieve an autoinhibitory effect, leading to increased NFAT. Our data indicate that GEF activity is critical for the function of Vav1 as a transforming protein but not for NFAT stimulation. The association of Vav1 with other proteins, detected by SH2 profiling, might affect other Vav1-dependent activities, such as NFAT stimulation.

  3. Trapping by amylose of the aliphatic chain grafted onto chlorogenic acid: importance of the graft position.

    PubMed

    Le-Bail, P; Lorentz, C; Pencreac'h, G; Soultani-Vigneron, S; Pontoire, B; López Giraldo, L J; Villeneuve, P; Hendrickx, J; Tran, V

    2015-03-06

    5-Caffeoylquinic acid (chlorogenic acid), is classified in acid-phenols family and as polyphenolic compounds it possesses antioxidant activity. The oxydative modification of chlorogenic acid in foods may lead to alteration of their qualities; to counteract these degradation effects, molecular encapsulation was used to protect chlorogenic acid. Amylose can interact strongly with a number of small molecules, including lipids. In order to enable chlorogenic acid complexation by amylose, a C16 aliphatic chain was previously grafted onto the cycle of quinic acid. This work showed that for the two lipophilic derivatives of chlorogenic acid: hexadecyl chlorogenate obtained by alkylation and 3-O-palmitoyl chlorogenic acid obtained by acylation; only the 3-O-palmitoyl chlorogenic acid complexed amylose. The chlorogenic acid derivatives were studied by X-ray diffraction, differential scanning calorimetry and NMR to elucidate the interaction. By comparing the results with previous work on the complexation of amylose by 4-O-palmitoyl chlorogenic acid, the importance of the aliphatic chain position on the cycle of the quinic acid is clearly highlighted. A study in molecular modeling helped to understand the difference in behavior relative to amylose of these three derivatives of chlorogenic acid.

  4. Heterotrophic denitrification plays an important role in N₂O production from nitritation reactors treating anaerobic sludge digestion liquor.

    PubMed

    Wang, Qilin; Jiang, Guangming; Ye, Liu; Pijuan, Maite; Yuan, Zhiguo

    2014-10-01

    Nitrous oxide (N2O) emissions from nitritation reactors receiving real anaerobic sludge digestion liquor have been reported to be substantially higher than those from reactors receiving synthetic digestion liquor. This study aims to identify the causes for the difference, and to develop strategies to reduce N2O emissions from reactors treating real digestion liquor. Two sequencing batch reactors (SBRs) performing nitritation, fed with real (SBR-R) and synthetic (SBR-S) digestion liquors, respectively, were employed. The N2O emission factors for SBR-R and SBR-S were determined to be 3.12% and 0.80% of the NH4(+)-N oxidized, respectively. Heterotrophic denitrification supported by the organic carbon present in the real digestion liquor was found to be the key contributor to the higher N2O emission from SBR-R. Heterotrophic nitrite reduction likely stopped at N2O (rather than N2), with a hypothesised cause being free nitrous acid inhibition. This implies that all nitrite reduced by heterotrophic bacteria was converted to and emitted as N2O. Increasing dissolved oxygen (DO) concentration from 0.5 to 1.0 mg/L, or above, decreased aerobic N2O production from 2.0% to 0.5% in SBR-R, whereas aerobic N2O production in SBR-S remained almost unchanged (at approximately 0.5%). We hypothesised that DO at 1 mg/L or above suppressed heterotrophic nitrite reduction thus reduced aerobic heterotrophic N2O production. We recommend that DO in a nitritation system receiving anaerobic sludge digestion liquor should be maintained at approximately 1 mg/L to minimise N2O emission.

  5. RAC1 GTPase plays an important role in γ-irradiation induced G2/M checkpoint activation

    PubMed Central

    2012-01-01

    Introduction In response to gamma-irradiation (IR)-induced double-strand DNA breaks, cells undergo cell-cycle arrest, allowing time for DNA repair before reentering the cell cycle. G2/M checkpoint activation involves activation of ataxia telangiectasia mutated (ATM)/ATM- and rad3-related (ATR) kinases and inhibition of Cdc25 phosphatases, resulting in inhibition of Cdc2 kinase and subsequent G2/M cell-cycle arrest. Previous studies from our laboratory showed that the G2/M checkpoint activation after IR exposure of MCF-7 breast cancer cells is dependent on the activation of extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) signaling. In the present studies, we investigated the role of Ras-related C3 botulinum toxin substrate 1 (Rac1) guanosine triphosphatase (GTPase) in IR-induced G2/M checkpoint response and ERK1/2 activation, as well as in cell survival after IR. Methods With Rac1-specific inhibitor, dominant negative mutant Rac1 (N17Rac1) and specific small interfering RNA, the effect of Rac1 on IR-induced G2/M checkpoint response and ERK1/2 activation was examined in human breast cancer cells. In addition, the effect of Rac1 on cell survival after irradiation was assessed by using Rac1-specific inhibitor. Results IR exposure of MCF-7 breast cancer cells was associated with a marked activation of Rac1 GTPase. Furthermore, inhibition of Rac1 by using specific inhibitor, dominant-negative Rac1 mutant, or specific siRNA resulted in attenuation of IR-induced G2/M arrest and concomitant diminution of IR-induced activation of ATM, ATR, Chk1, and Chk2 kinases, as well as phosphorylation of Cdc2-Tyr15. Moreover, Rac1 inhibition or decreased Rac1 expression also abrogated IR-induced phosphorylation of mitogen-activated protein kinase kinase 1 and 2 (MEK1/2) and ERK1/2. Ultimately, inhibition of Rac1 markedly increased cellular sensitivity to IR exposure, which involves induction of apoptosis. Conclusion Studies in this report suggest that Rac1 GTPase plays an

  6. Dihydroflavonol 4-Reductase Genes from Freesia hybrida Play Important and Partially Overlapping Roles in the Biosynthesis of Flavonoids

    PubMed Central

    Li, Yueqing; Liu, Xingxue; Cai, Xinquan; Shan, Xiaotong; Gao, Ruifang; Yang, Song; Han, Taotao; Wang, Shucai; Wang, Li; Gao, Xiang

    2017-01-01

    the divergence of the expression patterns for FhDFR genes might be controlled at transcriptional level, as the expression of FhDFR1/FhDFR2 and FhDFR3 was controlled by a potential MBW regulatory complex with different activation efficiencies. Therefore, it can be concluded that the DFR-like genes from F. hybrida have diverged during evolution to play partially overlapping roles in the flavonoid biosynthesis, and the results will contribute to the study of evolution of DFR gene families in angiosperms, especially for monocot plants.

  7. Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

    PubMed Central

    2011-01-01

    Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants. PMID:21718548

  8. ScMT2-1-3, a metallothionein gene of sugarcane, plays an important role in the regulation of heavy metal tolerance/accumulation.

    PubMed

    Guo, Jinlong; Xu, Liping; Su, Yachun; Wang, Hengbo; Gao, Shiwu; Xu, Jingsheng; Que, Youxiong

    2013-01-01

    Plant metallothioneins (MTs), which are cysteine-rich, low-molecular-weight, and metal-binding proteins, play important roles in detoxification, metal ion homeostasis, and metal transport adjustment. In this study, a novel metallothionein gene, designated as ScMT2-1-3 (GenBank Accession number JQ627644), was identified from sugarcane. ScMT2-1-3 was 700 bp long, including a 240 bp open reading frame (ORF) encoding 79 amino acid residues. A His-tagged ScMT2-1-3 protein was successfully expressed in Escherichia coli system which had increased the host cell's tolerance to Cd(2+), Cu(2+), PEG, and NaCl. The expression of ScMT2-1-3 was upregulated under Cu(2+) stress but downregulated under Cd(2+) stress. Real-time qPCR demonstrated that the expression levels of ScMT2-1-3 in bud and root were over 14 times higher than those in stem and leaf, respectively. Thus, both the E. coli assay and sugarcane plantlets assay suggested that ScMT2-1-3 is significantly involved in the copper detoxification and storage in the cell, but its functional mechanism in cadmium detoxification and storage in sugarcane cells needs more testification though its expressed protein could obviously increase the host E. coli cell's tolerance to Cd(2+). ScMT2-1-3 constitutes thus a new interesting candidate for elucidating the molecular mechanisms of MTs-implied plant heavy metal tolerance/accumulation and for developing sugarcane phytoremediator varieties.

  9. Human acyl-CoA dehydrogenase-9 plays a novel role in the mitochondrial beta-oxidation of unsaturated fatty acids.

    PubMed

    Ensenauer, Regina; He, Miao; Willard, Jan-Marie; Goetzman, Eric S; Corydon, Thomas J; Vandahl, Brian B; Mohsen, Al-Walid; Isaya, Grazia; Vockley, Jerry

    2005-09-16

    Unsaturated fatty acids play an important role in the prevention of human diseases such as diabetes, obesity, cancer, and neurodegeneration. However, their oxidation in vivo by acyl-CoA dehydrogenases (ACADs) that catalyze the first step of each cycle of mitochondrial fatty acid beta-oxidation is not entirely understood. Recently, a novel ACAD (ACAD-9) of unknown function that is highly homologous to human very-long-chain acyl-CoA dehydrogenase was identified by large-scale random sequencing. To characterize its enzymatic role, we have expressed ACAD-9 in Escherichia coli, purified it, and determined its pattern of substrate utilization. The N terminus of the mature form of the enzyme was identified by in vitro mitochondrial import studies of precursor protein. A 37-amino acid leader peptide was cleaved sequentially by two mitochondrial peptidases to yield a predicted molecular mass of 65 kDa for the mature subunit. Submitochondrial fractionation studies found native ACAD-9 to be associated with the mitochondrial membrane. Gel filtration analysis indicated that, like very-long-chain acyl-CoA dehydrogenase, ACAD-9 is a dimer, in contrast to the other known ACADs, which are tetramers. Purified mature ACAD-9 had maximal activity with long-chain unsaturated acyl-CoAs as substrates (C16:1-, C18:1-, C18:2-, C22:6-CoA). These results suggest a previously unrecognized role for ACAD-9 in the mitochondrial beta-oxidation of long-chain unsaturated fatty acids. Because of the substrate specificity and abundance of ACAD-9 in brain, we speculate that it may play a role in the turnover of lipid membrane unsaturated fatty acids that are essential for membrane integrity and structure.

  10. Phospholipase DZ2 plays an important role in extraplastidic galactolipid biosynthesis and phosphate recycling in Arabidopsis roots

    PubMed Central

    Cruz-Ramírez, Alfredo; Oropeza-Aburto, Araceli; Razo-Hernández, Francisco; Ramírez-Chávez, Enrique; Herrera-Estrella, Luis

    2006-01-01

    Low phosphate (Pi) availability is one of the major constraints for plant productivity in natural and agricultural ecosystems. Plants have evolved a myriad of developmental and biochemical mechanisms to increase internal Pi uptake and utilization efficiency. One important biochemical pathway leading to an increase in internal Pi availability is the hydrolysis of phospholipids. Hydrolyzed phospholipids are replaced by nonphosphorus lipids such as galactolipids and sulfolipids, which help to maintain the functionality and structure of membrane systems. Here we report that a member of the Arabidopsis phospholipase D gene family (PLDZ2) is gradually induced upon Pi starvation in both shoots and roots. From lipid content analysis we show that an Arabidopsis pldz2 mutant is defective in the hydrolysis of phospholipids and has a reduced capacity to accumulate galactolipids under limiting Pi conditions. Morphological analysis of the pldz2 root system shows a premature change in root architecture in response to Pi starvation. These results show that PLDZ2 is involved in the eukaryotic galactolipid biosynthesis pathway, specifically in hydrolyzing phosphatidylcholine and phosphatidylethanolamine to produce diacylglycerol for digalactosyldiacylglycerol synthesis and free Pi to sustain other Pi-requiring processes. PMID:16617110

  11. Surface texture and priming play important roles in predator recognition by the red-backed shrike in field experiments.

    PubMed

    Němec, Michal; Syrová, Michaela; Dokoupilová, Lenka; Veselý, Petr; Šmilauer, Petr; Landová, Eva; Lišková, Silvie; Fuchs, Roman

    2015-01-01

    We compared the responses of the nesting red-backed shrikes (Lanius collurio) to three dummies of a common nest predator, the Eurasian jay (Garrulus glandarius), each made from a different material (stuffed, plush, and silicone). The shrikes performed defensive behaviour including attacks on all three dummies. Nevertheless, the number of attacks significantly decreased from the stuffed dummy through the plush dummy and finally to the silicone dummy. Our results show that wild birds use not only colours but also other surface features as important cues for recognition and categorization of other bird species. Moreover, the silicone dummy was attacked only when presented after the stuffed or plush dummy. Thus, we concluded that the shrikes recognized the jay only the stuffed (with feathered surface) and plush (with hairy surface) dummies during the first encounter. Recognition of the silicon dummy (with glossy surface) was facilitated by previous encounters with the more accurate model. This process resembles the effect of perceptual priming, which is widely described in the literature on humans.

  12. Butyrate and deoxycholic acid play common and distinct roles in HCT116 human colon cell proliferation.

    PubMed

    Zeng, Huawei; Claycombe, Kate J; Reindl, Katie M

    2015-10-01

    Consumption of a high-fat diet causes an increase in bile acid deoxycholic acid (DCA) in colon lumen and colon cancer risk, while butyrate, an intestinal microbiota metabolite of dietary fiber, has been shown to exhibit colon cancer-preventive effects. To distinguish these opposing effects of DCA and butyrate (two major metabolites in colon lumen), we examined the effects of physiologically relevant doses of butyrate (0.5-2 mmol/l) and DCA (0.05-0.3 mmol/l) on colon cell proliferation. We hypothesize that butyrate and DCA each modulates the cell cycle and apoptosis via common and distinct cellular signaling targets. In this study, we demonstrated that both butyrate and DCA inhibited cell proliferation by up to 89% and 92% and increased cell apoptosis rate by up to 3.1- and 4.5-fold, respectively. Cell cycle analyses revealed that butyrate led to an increase in G1 and G2 fractions with a concomitant drop in the S-phase fraction, but DCA induced an increase in only G1 fraction with a concomitant drop in the S-phase fraction when compared with the untreated cells. The examination of early cellular signaling revealed that DCA but not butyrate increased intracellular reactive oxygen species, genomic DNA breakage, the activation of ERK1/2, caspase-3 and PARP. In contrast, DCA decreased activated Rb protein level, and butyrate but not DCA increased p21 expression. Collectively, although both butyrate and DCA inhibit colonic cell proliferation, butyrate increases tumor suppressor gene expression, whereas DCA decreases tumor suppressor activation in cell cycle and apoptosis pathways.

  13. Enhancer of zeste homologue 2 plays an important role in neuroblastoma cell survival independent of its histone methyltransferase activity.

    PubMed

    Bate-Eya, Laurel T; Gierman, Hinco J; Ebus, Marli E; Koster, Jan; Caron, Huib N; Versteeg, Rogier; Dolman, M Emmy M; Molenaar, Jan J

    2017-04-01

    Neuroblastoma is predominantly characterised by chromosomal rearrangements. Next to V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma Derived Homolog (MYCN) amplification, chromosome 7 and 17q gains are frequently observed. We identified a neuroblastoma patient with a regional 7q36 gain, encompassing the enhancer of zeste homologue 2 (EZH2) gene. EZH2 is the histone methyltransferase of lysine 27 of histone H3 (H3K27me3) that forms the catalytic subunit of the polycomb repressive complex 2. H3K27me3 is commonly associated with the silencing of genes involved in cellular processes such as cell cycle regulation, cellular differentiation and cancer. High EZH2 expression correlated with poor prognosis and overall survival independent of MYCN amplification status. Unexpectedly, treatment of 3 EZH2-high expressing neuroblastoma cell lines (IMR32, CHP134 and NMB), with EZH2-specific inhibitors (GSK126 and EPZ6438) resulted in only a slight G1 arrest, despite maximum histone methyltransferase activity inhibition. Furthermore, colony formation in cell lines treated with the inhibitors was reduced only at concentrations much higher than necessary for complete inhibition of EZH2 histone methyltransferase activity. Knockdown of the complete protein with three independent shRNAs resulted in a strong apoptotic response and decreased cyclin D1 levels. This apoptotic response could be rescued by overexpressing EZH2ΔSET, a truncated form of wild-type EZH2 lacking the SET transactivation domain necessary for histone methyltransferase activity. Our findings suggest that high EZH2 expression, at least in neuroblastoma, has a survival function independent of its methyltransferase activity. This important finding highlights the need for studies on EZH2 beyond its methyltransferase function and the requirement for compounds that will target EZH2 as a complete protein.

  14. Nitrite Reductase NirBD Is Induced and Plays an Important Role during In Vitro Dormancy of Mycobacterium tuberculosis

    PubMed Central

    Akhtar, Shamim; Khan, Arshad; Sohaskey, Charles D.; Jagannath, Chinnaswamy

    2013-01-01

    Mycobacterium tuberculosis is one of the strongest reducers of nitrate among all mycobacteria. Reduction of nitrate to nitrite, mediated by nitrate reductase (NarGHJI) of M. tuberculosis, is induced during the dormant stage, and the enzyme has a respiratory function in the absence of oxygen. Nitrite reductase (NirBD) is also functional during aerobic growth when nitrite is the sole nitrogen source. However, the role of NirBD-mediated nitrite reduction during the dormancy is not yet characterized. Here, we analyzed nitrite reduction during aerobic growth as well as in a hypoxic dormancy model of M. tuberculosis in vitro. When nitrite was used as the sole nitrogen source in the medium, the organism grew and the reduction of nitrite was evident in both hypoxic and aerobic cultures of M. tuberculosis. Remarkably, the hypoxic culture of M. tuberculosis, compared to the aerobic culture, showed 32- and 4-fold-increased expression of nitrite reductase (NirBD) at the transcription and protein levels, respectively. More importantly, a nirBD mutant of M. tuberculosis was unable to reduce nitrite and compared to the wild-type (WT) strain had a >2-log reduction in viability after 240 h in the Wayne model of hypoxic dormancy. Dependence of M. tuberculosis on nitrite reductase (NirBD) was also seen in a human macrophage-based dormancy model where the nirBD mutant was impaired for survival compared to the WT strain. Overall, the increased expression and essentiality of nitrite reductase in the in vitro dormancy models suggested that NirBD-mediated nitrite reduction could be critical during the persistent stage of M. tuberculosis. PMID:23935045

  15. Complement and the Alternative Pathway Play an Important Role in LPS/D-GalN-Induced Fulminant Hepatic Failure

    PubMed Central

    Zhao, Guangyu; Zhou, Xiaojun; Li, Junfeng; Hu, Jingya; Yu, Hong; Chen, Yu; Song, Hongbin; Qiao, Fei; Xu, Guilian; Yang, Fei; Wu, Yuzhang; Tomlinson, Stephen; Duan, Zhongping; Zhou, Yusen

    2011-01-01

    Fulminant hepatic failure (FHF) is a clinically severe type of liver injury with an extremely high mortality rate. Although the pathological mechanisms of FHF are not well understood, evidence suggests that the complement system is involved in the pathogenesis of a variety of liver disorders. In the present study, to investigate the role of complement in FHF, we examined groups of mice following intraperitoneal injection of LPS/D-GalN: wild-type C57BL/6 mice, wild-type mice treated with a C3aR antagonist, C5aR monoclonal antibody (C5aRmAb) or CR2-Factor H (CR2-fH, an inhibitor of the alternative pathway), and C3 deficient mice (C3−/− mice). The animals were euthanized and samples analyzed at specific times after LPS/D-GalN injection. The results show that intraperitoneal administration of LPS/D-GalN activated the complement pathway, as evidenced by the hepatic deposition of C3 and C5b-9 and elevated serum levels of the complement activation product C3a, the level of which was associated with the severity of the liver damage. C3a receptor (C3aR) and C5a receptor (C5aR) expression was also upregulated. Compared with wild-type mice, C3−/− mice survived significantly longer and displayed reduced liver inflammation and attenuated pathological damage following LPS/D-GalN injection. Similar levels of protection were seen in mice treated with C3aR antagonist,C5aRmAb or CR2-fH. These data indicate an important role for the C3a and C5a generated by the alternative pathway in LPS/D-GalN-induced FHF. The data further suggest that complement inhibition may be an effective strategy for the adjunctive treatment of fulminant hepatic failure. PMID:22069473

  16. Salicylic acid is important for basal defense of Solanum tuberosum against Phytophthora infestans.

    PubMed

    Halim, Vincentius A; Eschen-Lippold, Lennart; Altmann, Simone; Birschwilks, Mandy; Scheel, Dierk; Rosahl, Sabine

    2007-11-01

    The importance of the signaling compound salicylic acid for basal defense of potato (Solanum tuberosum L. cv. Désirée) against Phytophthora infestans, the causal agent of late blight disease, was assessed using transgenic NahG potato plants which are unable to accumulate salicylic acid. Although the size of lesions caused by P. infestans was not significantly different in wild-type and transgenic NahG plants, real-time polymerase chain reaction analyses revealed a drastic enhancement of pathogen growth in potato plants depleted of salicylic acid. Increased susceptibility of NahG plants correlated with compromised callose formation and reduced early defense gene expression. NahG plants pretreated with the salicylic acid analog 2,6-dichloro-isonicotinic acid allowed pathogen growth to a similar extent as did wild-type plants, indicating that salicylic acid is an important compound required for basal defense of potato against P. infestans.

  17. Autocrine abscisic acid plays a key role in quartz-induced macrophage activation.

    PubMed

    Magnone, Mirko; Sturla, Laura; Jacchetti, Emanuela; Scarfì, Sonia; Bruzzone, Santina; Usai, Cesare; Guida, Lucrezia; Salis, Annalisa; Damonte, Gianluca; De Flora, Antonio; Zocchi, Elena

    2012-03-01

    Inhalation of quartz induces silicosis, a lung disease where alveolar macrophages release inflammatory mediators, including prostaglandin-E(2) (PGE(2)) and tumor necrosis factor α (TNF-α). Here we report the pivotal role of abscisic acid (ABA), a recently discovered human inflammatory hormone, in silica-induced activation of murine RAW264.7 macrophages and of rat alveolar macrophages (AMs). Stimulation of both RAW264.7 cells and AMs with quartz induced a significant increase of ABA release (5- and 10-fold, respectively), compared to untreated cells. In RAW264.7 cells, autocrine ABA released after quartz stimulation sequentially activates the plasma membrane receptor LANCL2 and NADPH oxidase, generating a Ca(2+) influx resulting in NFκ B nuclear translocation and PGE(2) and TNF-α release (3-, 2-, and 3.5-fold increase, respectively, compared to control, unstimulated cells). Quartz-stimulated RAW264.7 cells silenced for LANCL2 or preincubated with a monoclonal antibody against ABA show an almost complete inhibition of NFκ B nuclear translocation and PGE(2) and TNF-α release compared to controls electroporated with a scramble oligonucleotide or preincubated with an unrelated antibody. AMs showed similar early and late ABA-induced responses as RAW264.7 cells. These findings identify ABA and LANCL2 as key mediators in quartz-induced inflammation, providing possible new targets for antisilicotic therapy.

  18. Does Lysosomial Acid Lipase Reduction Play a Role in Adult Non-Alcoholic Fatty Liver Disease?

    PubMed Central

    Baratta, Francesco; Pastori, Daniele; Polimeni, Licia; Tozzi, Giulia; Violi, Francesco; Angelico, Francesco; Del Ben, Maria

    2015-01-01

    Lysosomal Acid Lipase (LAL) is a key enzyme involved in lipid metabolism, responsible for hydrolysing the cholesteryl esters and triglycerides. Wolman Disease represents the early onset phenotype of LAL deficiency rapidly leading to death. Cholesterol Ester Storage Disease is a late onset phenotype that occurs with fatty liver, elevated aminotransferase levels, hepatomegaly and dyslipidaemia, the latter characterized by elevated LDL-C and low HDL-C. The natural history and the clinical manifestations of the LAL deficiency in adults are not well defined, and the diagnosis is often incidental. LAL deficiency has been suggested as an under-recognized cause of dyslipidaemia and fatty liver. Therefore, LAL activity may be reduced also in non-obese patients presenting non-alcoholic fatty liver disease (NAFLD), unexplained persistently elevated liver transaminases or with elevation in LDL cholesterol. In these patients, it could be indicated to test LAL activity. So far, very few studies have been performed to assess LAL activity in representative samples of normal subjects or patients with NAFLD. Moreover, no large study has been carried out in adult subjects with NAFLD or cryptogenic cirrhosis. PMID:26602919

  19. Does α-amino-β-methylaminopropionic acid (BMAA) play a role in neurodegeneration?

    PubMed

    Chiu, Alexander S; Gehringer, Michelle M; Welch, Jeffrey H; Neilan, Brett A

    2011-09-01

    The association of α-amino-β-methylaminopropionic acid (BMAA) with elevated incidence of amyotrophic lateral sclerosis/Parkinson's disease complex (ALS/PDC) was first identified on the island of Guam. BMAA has been shown to be produced across the cyanobacterial order and its detection has been reported in a variety of aquatic and terrestrial environments worldwide, suggesting that it is ubiquitous. Various in vivo studies on rats, mice, chicks and monkeys have shown that it can cause neurodegenerative symptoms such as ataxia and convulsions. Zebrafish research has also shown disruption to neural development after BMAA exposure. In vitro studies on mice, rats and leeches have shown that BMAA acts predominantly on motor neurons. Observed increases in the generation of reactive oxygen species (ROS) and Ca(2+) influx, coupled with disruption to mitochondrial activity and general neuronal death, indicate that the main mode of activity is via excitotoxic mechanisms. The current review pertaining to the neurotoxicity of BMAA clearly demonstrates its ability to adversely affect neural tissues, and implicates it as a potentially significant compound in the aetiology of neurodegenerative disease. When considering the potential adverse health effects upon exposure to this compound, further research to better understand the modes of toxicity of BMAA and the environmental exposure limits is essential.

  20. Does Lysosomial Acid Lipase Reduction Play a Role in Adult Non-Alcoholic Fatty Liver Disease?

    PubMed

    Baratta, Francesco; Pastori, Daniele; Polimeni, Licia; Tozzi, Giulia; Violi, Francesco; Angelico, Francesco; Del Ben, Maria

    2015-11-25

    Lysosomal Acid Lipase (LAL) is a key enzyme involved in lipid metabolism, responsible for hydrolysing the cholesteryl esters and triglycerides. Wolman Disease represents the early onset phenotype of LAL deficiency rapidly leading to death. Cholesterol Ester Storage Disease is a late onset phenotype that occurs with fatty liver, elevated aminotransferase levels, hepatomegaly and dyslipidaemia, the latter characterized by elevated LDL-C and low HDL-C. The natural history and the clinical manifestations of the LAL deficiency in adults are not well defined, and the diagnosis is often incidental. LAL deficiency has been suggested as an under-recognized cause of dyslipidaemia and fatty liver. Therefore, LAL activity may be reduced also in non-obese patients presenting non-alcoholic fatty liver disease (NAFLD), unexplained persistently elevated liver transaminases or with elevation in LDL cholesterol. In these patients, it could be indicated to test LAL activity. So far, very few studies have been performed to assess LAL activity in representative samples of normal subjects or patients with NAFLD. Moreover, no large study has been carried out in adult subjects with NAFLD or cryptogenic cirrhosis.

  1. Extensive mutagenesis of a transcriptional activation domain identifies single hydrophobic and acidic amino acids important for activation in vivo.

    PubMed Central

    Sainz, M B; Goff, S A; Chandler, V L

    1997-01-01

    C1 is a transcriptional activator of genes encoding biosynthetic enzymes of the maize anthocyanin pigment pathway. C1 has an amino terminus homologous to Myb DNA-binding domains and an acidic carboxyl terminus that is a transcriptional activation domain in maize and yeast cells. To identify amino acids critical for transcriptional activation, an extensive random mutagenesis of the C1 carboxyl terminus was done. The C1 activation domain is remarkably tolerant of amino acid substitutions, as changes at 34 residues had little or no effect on transcriptional activity. These changes include introduction of helix-incompatible amino acids throughout the C1 activation domain and alteration of most single acidic amino acids, suggesting that a previously postulated amphipathic alpha-helix is not required for activation. Substitutions at two positions revealed amino acids important for transcriptional activation. Replacement of leucine 253 with a proline or glutamine resulted in approximately 10% of wild-type transcriptional activation. Leucine 253 is in a region of C1 in which several hydrophobic residues align with residues important for transcriptional activation by the herpes simplex virus VP16 protein. However, changes at all other hydrophobic residues in C1 indicate that none are critical for C1 transcriptional activation. The other important amino acid in C1 is aspartate 262, as a change to valine resulted in only 24% of wild-type transcriptional activation. Comparison of our C1 results with those from VP16 reveal substantial differences in which amino acids are required for transcriptional activation in vivo by these two acidic activation domains. PMID:8972191

  2. Electron Transfer Studies of Ruthenium(II) Complexes with Biologically Important Phenolic Acids and Tyrosine.

    PubMed

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Rajagopal, Seenivasan

    2016-03-01

    The ruthenium(II) complexes having 2,2'-bipyridine and phenanthroline derivatives are synthesized and characterized. The photophysical properties of these complexes at pH 12.5 are studied. The electron transfer reaction of biologically important phenolic acids and tyrosine are studied using absorption, emission and transient absorption spectral techniques. Semiclassical theory is applied to calculate the rate of electron transfer between ruthenium(II) complexes and biologically important phenolic acids.

  3. The importance of play in promoting healthy child development and maintaining strong parent-child bond: focus on children in poverty.

    PubMed

    Milteer, Regina M; Ginsburg, Kenneth R

    2012-01-01

    Play is essential to the social, emotional, cognitive, and physical well-being of children beginning in early childhood. It is a natural tool for children to develop resiliency as they learn to cooperate, overcome challenges, and negotiate with others. Play also allows children to be creative. It provides time for parents to be fully engaged with their children, to bond with their children, and to see the world from the perspective of their child. However, children who live in poverty often face socioeconomic obstacles that impede their rights to have playtime, thus affecting their healthy social-emotional development. For children who are underresourced to reach their highest potential, it is essential that parents, educators, and pediatricians recognize the importance of lifelong benefits that children gain from play.

  4. Structured Parent-Child Observations Predict Development of Conduct Problems: the Importance of Parental Negative Attention in Child-Directed Play.

    PubMed

    Fleming, Andrew P; McMahon, Robert J; King, Kevin M

    2017-04-01

    Structured observations of parent-child interactions are commonly used in research and clinical settings, but require additional empirical support. The current study examined the capacity of child-directed play, parent-directed play, and parent-directed chore interaction analogs to uniquely predict the development of conduct problems across a 6-year follow-up period. Parent-child observations were collected from 338 families from high-risk neighborhoods during the summer following the child's first-grade year. Participating children were 49.2 % female, 54.4 % white, and 45.6 % black, and had an average age of 7.52 years at the first assessment. Conduct problems were assessed via parent report and teacher report at five assessment points between first grade and seventh grade. Latent growth curve modeling was used to analyze predictors of conduct problem trajectory across this 6-year follow-up period. When race, sex, socioeconomic status, and maternal depressive symptoms were controlled, parental negative attention during child-directed play predicted higher levels of parent-reported conduct problems concurrently and after a 6-year follow-up period. Parental negative attention during child-directed play also predicted higher teacher-reported conduct problems 6 years later. Findings support the use of child-directed play and parent-directed chore analogs in predicting longitudinal development of conduct problems. The presence of parental negative attention during child-directed play appears to be an especially important predictor of greater conduct problems over time and across multiple domains. Additionally, the potential importance of task-incongruent behavior is proposed for further study.

  5. Disentangling the interactions between photochemical and bacterial degradation of dissolved organic matter: amino acids play a central role.

    PubMed

    Amado, André M; Cotner, James B; Cory, Rose M; Edhlund, Betsy L; McNeill, Kristopher

    2015-04-01

    Photochemical and bacterial degradation are important pathways to carbon mineralization and can be coupled in dissolved organic matter (DOM) decomposition. However, details of several mechanisms of the coupled photochemical and biological processing of DOM remain too poorly understood to achieve accurate predictions of the impact of these processes on DOM fate and reactivity. The aim of this study was to evaluate how photochemical degradation of amino acids affects bacterial metabolism and whether or not photochemical degradation of DOM competes for amino acids with biological processes. We examined the interactions between photochemical and bacterial degradation dynamics using a mixture of 18 amino acids and examined their dynamics and turnover rates within a larger pool of allochthonous or autochthonous DOM. We observed that photochemical exposure of DOM containing amino acids led to delayed biomass production (even though the final biomass did not differ), most likely due to a need for upregulation of biosynthetic pathways for amino acids that were damaged by photochemically produced reactive oxygen species (ROS). This response was most pronounced in bacterial communities where the abundance of photosensitive amino acids was highest (amended treatments and autochthonous DOM) and least pronounced when the abundance of these amino acids was low (unamended and allochthonous DOM), likely because these bacteria already had these biosynthetic pathways functioning. We observed both a cost and benefit associated with photochemical exposure of DOM. We observed a cost associated with photochemically produced ROS that partially degrade key amino acids and a benefit associated with an increase in the availability of other compounds in the DOM. Bacteria growing on DOM sources that are low in labile amino acids, such as those in terrestrially influenced environments, experience more of the benefits associated with photochemical exposure, whereas bacteria growing in more amino

  6. Importance of tetrahydroiso alpha-acids to the microbiological stability of beer.

    PubMed

    Caballero, Isabel; Agut, Montserrat; Armentia, Alicia; Blanco, Carlos A

    2009-01-01

    While beer provides a very stable microbiological environment, a few niche microorganisms are capable of growth in malt, wort, and beer. The production of off-flavors and development of turbidity in the packaged product are due to the growth and metabolic activity of wild yeast, certain lactic acid bacteria (LAB) and anaerobic Gram-negative bacteria. Beer also contains bitter hop compounds, which are toxic to Gram-positive and Gram-negative bacteria, and contribute to preventing the spoilage of this beverage. In the boiling process, the hop alpha-acids (humulones) are isomerized into iso alpha-acids. These products are responsible for the bitter taste of beer, but they also play an essential role in enhancing foam stability. Antibacterial activity of iso alpha-acids and their hydrogenated derivates (rhoiso alpha-acids and tetrahydroiso alpha-acids) in MRS broth and beer have been evaluated against different LAB (Lactobacillus and Pediococcus) for the determination of their beer-stabilizing capabilities. Besides this, we have determined the minimum inhibitory concentration and the bacteriostatic effect of each compound against Pediococcus. We found that tetrahydroiso alpha-acids (added directly to beer during production processes) are the compounds that present the greatest antibacterial activity against the main agents implicated in beer spoilage.

  7. Quorum sensing and indole-3-acetic acid degradation play a role in colonization and plant growth promotion of Arabidopsis thaliana by Burkholderia phytofirmans PsJN.

    PubMed

    Zúñiga, Ana; Poupin, María Josefina; Donoso, Raúl; Ledger, Thomas; Guiliani, Nicolás; Gutiérrez, Rodrigo A; González, Bernardo

    2013-05-01

    Although not fully understood, molecular communication in the rhizosphere plays an important role regulating traits involved in plant-bacteria association. Burkholderia phytofirmans PsJN is a well-known plant-growth-promoting bacterium, which establishes rhizospheric and endophytic colonization in different plants. A competent colonization is essential for plant-growth-promoting effects produced by bacteria. Using appropriate mutant strains of B. phytofirmans, we obtained evidence for the importance of N-acyl homoserine lactone-mediated (quorum sensing) cell-to-cell communication in efficient colonization of Arabidopsis thaliana plants and the establishment of a beneficial interaction. We also observed that bacterial degradation of the auxin indole-3-acetic acid (IAA) plays a key role in plant-growth-promoting traits and is necessary for efficient rhizosphere colonization. Wildtype B. phytofirmans but not the iacC mutant in IAA mineralization is able to restore promotion effects in roots of A. thaliana in the presence of exogenously added IAA, indicating the importance of this trait for promoting primary root length. Using a transgenic A. thaliana line with suppressed auxin signaling (miR393) and analyzing the expression of auxin receptors in wild-type inoculated plants, we provide evidence that auxin signaling in plants is necessary for the growth promotion effects produced by B. phytofirmans. The interplay between ethylene and auxin signaling was also confirmed by the response of the plant to a 1-aminocyclopropane-1-carboxylate deaminase bacterial mutant strain.

  8. Assessment of oil content and fatty acid composition variability in two economically important Hibiscus species.

    PubMed

    Wang, Ming Li; Morris, Brad; Tonnis, Brandon; Davis, Jerry; Pederson, Gary A

    2012-07-04

    The Hibiscus genus encompasses more than 300 species, but kenaf (Hibiscus cannabinus L.) and roselle (Hibiscus sabdariffa L.) are the two most economically important species within the genus. Seeds from these two Hibiscus species contain a relatively high amount of oil with two unusual fatty acids: dihydrosterculic and vernolic acids. The fatty acid composition in the oil can directly affect oil quality and its utilization. However, the variability in oil content and fatty acid composition for these two species is unclear. For these two species, 329 available accessions were acquired from the USDA germplasm collection. Their oil content and fatty acid composition were determined by nuclear magnetic resonance (NMR) and gas chromatography (GC), respectively. Using NMR and GC analyses, we found that Hibiscus seeds on average contained 18% oil and seed oil was composed of six major fatty acids (each >1%) and seven minor fatty acids (each <1%). Hibiscus cannabinus seeds contained significantly higher amounts of oil (18.14%), palmitic (20.75%), oleic (28.91%), vernolic acids (VA, 4.16%), and significantly lower amounts of stearic (3.96%), linoleic (39.49%), and dihydrosterculic acids (DHSA, 1.08%) than H. sabdariffa seeds (17.35%, 18.52%, 25.16%, 3.52%, 4.31%, 44.72%, and 1.57%, respectively). For edible oils, a higher oleic/linoleic (O/L) ratio and lower level of DHSA are preferred, and for industrial oils a high level of VA is preferred. Our results indicate that seeds from H. cannabinus may be of higher quality than H. sabdariffa seeds for these reasons. Significant variability in oil content and major fatty acids was also detected within both species. The variability in oil content and fatty acid composition revealed from this study will be useful for exploring seed utilization and developing new cultivars in these Hibiscus species.

  9. Steroidogenesis in MA-10 mouse Leydig cells is altered via fatty acid import into the mitochondria.

    PubMed

    Rone, Malena B; Midzak, Andrew S; Martinez-Arguelles, Daniel B; Fan, Jinjiang; Ye, Xiaoying; Blonder, Josip; Papadopoulos, Vassilios

    2014-10-01

    Mitochondria are home to many cellular processes, including oxidative phosphorylation and fatty acid metabolism, and in steroid-synthesizing cells, they are involved in cholesterol import and metabolism, which is the initiating step in steroidogenesis. The formation of macromolecular protein complexes aids in the regulation and efficiency of these mitochondrial functions, though because of their dynamic nature, they are hard to identify. To overcome this problem, we used Blue-Native PAGE with whole-gel mass spectrometry on isolated mitochondria from control and hormone-treated MA-10 mouse tumor Leydig cells. The presence of multiple mitochondrial protein complexes was shown. Although these were qualitatively similar under control and human chorionic gonadotropin (hCG)-stimulated conditions, quantitative differences in the components of the complexes emerged after hCG treatment. A prominent decrease was observed with proteins involved in fatty acid import into the mitochondria, implying that mitochondrial beta-oxidation is not essential for steroidogenesis. To confirm this observation, we inhibited fatty acid import utilizing the CPT1a inhibitor etomoxir, resulting in increased steroid production. Conversely, stimulation of mitochondrial beta-oxidation with metformin resulted in a dose-dependent reduction in steroidogenesis. These changes were accompanied by changes in mitochondrial respiration and in the lactic acid formed during glycolysis. Taken together, these results suggest that upon hormonal stimulation, mitochondria efficiently import cholesterol for steroid production at the expense of other lipids necessary for energy production, specifically fatty acids required for beta-oxidation.

  10. Multiple Genome Sequences of Important Beer-Spoiling Lactic Acid Bacteria

    PubMed Central

    Geissler, Andreas J.; Vogel, Rudi F.

    2016-01-01

    Seven strains of important beer-spoiling lactic acid bacteria were sequenced using single-molecule real-time sequencing. Complete genomes were obtained for strains of Lactobacillus paracollinoides, Lactobacillus lindneri, and Pediococcus claussenii. The analysis of these genomes emphasizes the role of plasmids as the genomic foundation of beer-spoiling ability. PMID:27795248

  11. Assessment of oil content and fatty acid composition variability in two economically important Hibiscus species.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Hibiscus genus encompasses more than 300 species, but kenaf (H. cannabinus L.) and roselle (H. sabdariffa L.) are the two most economically important species within the genus. Seeds from these two Hibiscus species contain a relatively high amount of oil with two unusual fatty acids: dihydrosterc...

  12. The purple acid phosphatase GmPAP21 enhances internal phosphorus utilization and possibly plays a role in symbiosis with rhizobia in soybean.

    PubMed

    Li, Chengchen; Li, Caifeng; Zhang, Haiyan; Liao, Hong; Wang, Xiurong

    2017-02-01

    Induction of secreted and intracellular purple acid phosphatases (PAPs; EC 3.1.3.2) is widely recognized as an adaptation of plants to phosphorus (P) deficiency. The secretion of PAPs plays important roles in P acquisition. However, little is known about the functions of intracellular PAP in plants and nodules. In this study, we identified a novel PAP gene GmPAP21 in soybean. Expression of GmPAP21 was induced by P limitation in nodules, roots and old leaves, and increased in roots with increasing duration of P starvation. Furthermore, the induction of GmPAP21 in nodules and roots was more intensive than in leaves in both P-efficient genotype HN89 and P-inefficient genotype HN112 in response to P starvation, and the relative expression in the leaves and nodules of HN89 was significantly greater than that of HN112 after P deficiency treatment. Further functional analyses showed that over-expressing GmPAP21 significantly enhanced both acid phosphatase activity and growth performance of hairy roots under P starvation condition, indicating that GmPAP21 plays an important role in P utilization. Moreover, GUS expression driven by GmPAP21 promoter was shown in the nodules besides roots. Overexpression of GmPAP21 in transgenic soybean significantly inhibited nodule growth, and thereby affected plant growth after inoculation with rhizobia. This suggests that GmPAP21 is also possibly involved in regulating P metabolism in nodules. Taken together, our results suggest that GmPAP21 is a novel plant PAP that functions in the adaptation of soybean to P starvation, possibly through its involvement in P recycling in plants and P metabolism in nodules.

  13. The increased number of tumor-associated macrophage is associated with overexpression of VEGF-C, plays an important role in Kazakh ESCC invasion and metastasis.

    PubMed

    Hu, Jian Ming; Liu, Kai; Liu, Ji Hong; Jiang, Xian Li; Wang, Xue Li; Yang, Lan; Chen, Yun Zhao; Liu, Chun Xia; Li, Shu Gang; Cui, Xiao Bin; Zou, Hong; Pang, Li Juan; Zhao, Jin; Qi, Yan; Liang, Wei Hua; Yuan, Xiang Lin; Li, Feng

    2017-02-01

    Tumor associated macrophages (TAMs) play an important role in the growth, progression, and metastasis of tumors. The distribution of TAMs in Kazakh esophageal squamous cell carcinoma (ESCC) is not determined. We aimed to investigate the role of TAMs in the occurrence and progression of Kazakh ESCC. CD163 was used as the TAM marker, and immunohistochemistry (IHC) counts were used to quantify the density of TAMs in tumor nest and surrounding stroma. IHC staining was used to evaluate the expression of vascular endothelial growth factor C (VEGF-C) in Kazakh ESCC and cancer adjacent normal (CAN) tissues. The density of TAMs in Kazakh ESCCs tumor nest and stromal was significantly higher than that in CAN tissues. The increased number of CD163-positive TAMs in tumor nest and tumor stromal was positively associated with Kazakh ESCC lymph node metastasis and clinical stage progression. Meanwhile, the expression of VEGF-C in Kazakh ESCCs was significantly higher than that in CAN tissues. Overexpression of VEGF-C in Kazakh ESCCs was significantly associated with gender, depth of tumor invasion, lymph node metastasis and tumor clinical stage. The increased number of TAMs, either in the tumor nests or tumor stroma was positively correlated with the overexpression of VEGF-C, which may promote lymphangiogenesis and play an important role in the invasion and metastasis of Kazakh ESCC.

  14. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids

    PubMed Central

    Galloway, Aaron W. E.; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  15. Partitioning the Relative Importance of Phylogeny and Environmental Conditions on Phytoplankton Fatty Acids.

    PubMed

    Galloway, Aaron W E; Winder, Monika

    2015-01-01

    Essential fatty acids (EFA), which are primarily generated by phytoplankton, limit growth and reproduction in diverse heterotrophs. The biochemical composition of phytoplankton is well-known to be governed both by phylogeny and environmental conditions. Nutrients, light, salinity, and temperature all affect both phytoplankton growth and fatty acid composition. However, the relative importance of taxonomy and environment on algal fatty acid content has yet to be comparatively quantified, thus inhibiting predictions of changes to phytoplankton food quality in response to global environmental change. We compiled 1145 published marine and freshwater phytoplankton fatty acid profiles, consisting of 208 species from six major taxonomic groups, cultured in a wide range of environmental conditions, and used a multivariate distance-based linear model to quantify the total variation explained by each variable. Our results show that taxonomic group accounts for 3-4 times more variation in phytoplankton fatty acids than the most important growth condition variables. The results underscore that environmental conditions clearly affect phytoplankton fatty acid profiles, but also show that conditions account for relatively low variation compared to phylogeny. This suggests that the underlying mechanism determining basal food quality in aquatic habitats is primarily phytoplankton community composition, and allows for prediction of environmental-scale EFA dynamics based on phytoplankton community data. We used the compiled dataset to calculate seasonal dynamics of long-chain EFA (LCEFA; ≥C20 ɷ-3 and ɷ-6 polyunsaturated fatty acid) concentrations and ɷ-3:ɷ-6 EFA ratios in Lake Washington using a multi-decadal phytoplankton community time series. These analyses quantify temporal dynamics of algal-derived LCEFA and food quality in a freshwater ecosystem that has undergone large community changes as a result of shifting resource management practices, highlighting diatoms

  16. TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

    PubMed

    Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

    2016-09-25

    The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis.

  17. Fatty acid degradation plays an essential role in proliferation of mouse female primordial germ cells via the p53-dependent cell cycle regulation

    PubMed Central

    Teng, Hui; Sui, Xuesong; Zhou, Cheng; Shen, Cong; Yang, Ye; Zhang, Pang; Guo, Xuejiang; Huo, Ran

    2016-01-01

    ABSTRACT Primordial germ cells (PGCs) are embryonic founders of germ cells that ultimately differentiate into oocytes and spermatogonia. Embryonic proliferation of PGCs starting from E11.5 ensures the presence of germ cells in adulthood, especially in female mammals whose total number of oocytes declines after this initial proliferation period. To better understand mechanisms underlying PGC proliferation in female mice, we constructed a proteome profile of female mouse gonads at E11.5. Subsequent KEGG pathway analysis of the 3,662 proteins profiled showed significant enrichment of pathways involved in fatty acid degradation. Further, the number of PGCs found in in vitro cultured fetal gonads significantly decreased with application of etomoxir, an inhibitor of the key rate-limiting enzyme of fatty acid degradation carnitine acyltransferase I (CPT1). Decrease in PGCs was further determined to be the result of reduced proliferation rather than apoptosis. The inhibition of fatty acid degradation by etomoxir has the potential to activate the Ca2+/CamKII/5′-adenosine monophosphate-activated protein kinase (AMPK) pathway; while as an upstream activator, activated AMPK can function as activator of p53 to induce cell cycle arrest. Thus, we detected the expressional level of AMPK, phosphorylated AMPK (P-AMPK), phosphorylated p53 (P-p53) and cyclin-dependent kinase inhibitor 1 (p21) by Western blots, the results showed increased expression of them after treatment with etomoxir, suggested the activation of p53 pathway was the reason for reduced proliferation of PGCs. Finally, the involvement of p53-dependent G1 cell cycle arrest in defective proliferation of PGCs was verified by rescue experiments. Our results demonstrate that fatty acid degradation plays an important role in proliferation of female PGCs via the p53-dependent cell cycle regulation. PMID:26716399

  18. The DNase domain-containing protein TATDN1 plays an important role in chromosomal segregation and cell cycle progression during zebrafish eye development

    PubMed Central

    Yang, Hui; Liu, Changwei; Jamsen, Joonas; Wu, Zhenxing; Wang, Yingjie; Chen, Jun; Zheng, Li; Shen, Binghui

    2012-01-01

    The DNase domain-containing protein TATDN1 is a conserved nuclease in both prokaryotes and eukaryotes. It was previously implicated to play a role in apoptotic DNA fragmentation in yeast and C. elegans. However, its biological function in higher organisms, such as vertebrates, is unknown. Here, we report that zebrafish TATDN1 (zTATDN1) possesses a novel endonuclease activity, which first makes a nick at the DNA duplex and subsequently converts the nick into a DNA double-strand break in vitro. This biochemical property allows zTATDN1 to catalyze decatenation of catenated kinetoplast DNA to produce separated linear DNA in vitro. We further determine that zTATDN1 is predominantly expressed in eye cells during embryonic development. Knockdown of TATDN1 in zebrafish embryos results in an abnormal cell cycle progression, formation of polyploidy and aberrant chromatin structures. Consequently, the TATDN1-deficient morphants have disordered eye cell layers and significantly smaller eyes compared with the WT control. Altogether, our current studies suggest that zTATDN1 plays an important role in chromosome segregation and eye development in zebrafish. PMID:23187801

  19. The Cyclin-Dependent Kinase Inhibitor Orysa;KRP1 Plays an Important Role in Seed Development of Rice1[W

    PubMed Central

    Barrôco, Rosa Maria; Peres, Adrian; Droual, Anne-Marie; De Veylder, Lieven; Nguyen, Le Son Long; De Wolf, Joris; Mironov, Vladimir; Peerbolte, Rindert; Beemster, Gerrit T.S.; Inzé, Dirk; Broekaert, Willem F.; Frankard, Valerie

    2006-01-01

    Kip-related proteins (KRPs) play a major role in the regulation of the plant cell cycle. We report the identification of five putative rice (Oryza sativa) proteins that share characteristic motifs with previously described plant KRPs. To investigate the function of KRPs in rice development, we generated transgenic plants overexpressing the Orysa;KRP1 gene. Phenotypic analysis revealed that overexpressed KRP1 reduced cell production during leaf development. The reduced cell production in the leaf meristem was partly compensated by an increased cell size, demonstrating the existence of a compensatory mechanism in monocot species by which growth rate is less reduced than cell production, through cell expansion. Furthermore, Orysa;KRP1 overexpression dramatically reduced seed filling. Sectioning through the overexpressed KRP1 seeds showed that KRP overproduction disturbed the production of endosperm cells. The decrease in the number of fully formed seeds was accompanied by a drop in the endoreduplication of endosperm cells, pointing toward a role of KRP1 in connecting endocycle with endosperm development. Also, spatial and temporal transcript detection in developing seeds suggests that Orysa;KRP1 plays an important role in the exit from the mitotic cell cycle during rice grain formation. PMID:17012406

  20. Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

    PubMed Central

    Robert, Agnes; Mfilinge, Prosper; Limbu, Samwel M.; Mwita, Chacha J.

    2014-01-01

    Fatty acids (FAs) particularly ω3 and ω6 polyunsaturated fatty acids (PUFAs) play important role in human health. This study aimed to investigate the composition and levels of selected ω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus), Nile tilapia (Oreochromis niloticus), Tilapia zillii, and dagaa (Rastrineobola argentea) from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA), eicosapentaenoic (EPA), docosapentaenoic (DPA), and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34) compared to L. niloticus (27), T. zillii (26), and R. argentea (21). The levels of EPA differed significantly among the four commercial fish species (F = 6.19,  P = 0.001). The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (F = 0.652,  P = 0.583). The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of ω3 FAs, mainly EPA. PMID:25610654

  1. Elevated levels of perfluoroalkyl acids in family members of occupationally exposed workers: the importance of dust transfer

    PubMed Central

    Fu, Jianjie; Gao, Yan; Wang, Thanh; Liang, Yong; Zhang, Aiqian; Wang, Yawei; Jiang, Guibin

    2015-01-01

    The exposure pathways of perfluoroalkyl acids (PFAAs) to humans are still not clear because of the complex living environment, and few studies have simultaneously investigated the bioaccumulative behaviour of different PFAAs in humans. In this study, serum, dust, duplicate diet, and other matrices were collected around a manufacturing plant in China, and homologous series of PFAAs were analysed. PFAA levels in dust and serum of local residents in this area were considerably higher than those in non-polluted area. Although dietary intake was the major exposure pathway in the present study, dust ingestion played an important role in this case. Serum PFAAs in local residents was significantly correlated with dust PFAAs levels in their living or working microenvironment. Serum PFAAs and dust PFAAs were significantly higher in family members of occupational workers (FM) than in ordinary residents (OR) (p < 0.01). After a careful analysis of the PFAAs exposure pathway, a potential pathway in addition to direct dust ingestion was suggested: PFAAs might transferred from occupational worker's clothes to dinners via cooking processes. The bioaccumulative potential of PFHxS and PFOS were higher than other PFAAs, which suggested a substantial difference between the bioaccumulative ability of perfluorinated sulfonic acids and perfluorinated carboxylic acids. PMID:25791573

  2. Elevated levels of perfluoroalkyl acids in family members of occupationally exposed workers: the importance of dust transfer

    NASA Astrophysics Data System (ADS)

    Fu, Jianjie; Gao, Yan; Wang, Thanh; Liang, Yong; Zhang, Aiqian; Wang, Yawei; Jiang, Guibin

    2015-03-01

    The exposure pathways of perfluoroalkyl acids (PFAAs) to humans are still not clear because of the complex living environment, and few studies have simultaneously investigated the bioaccumulative behaviour of different PFAAs in humans. In this study, serum, dust, duplicate diet, and other matrices were collected around a manufacturing plant in China, and homologous series of PFAAs were analysed. PFAA levels in dust and serum of local residents in this area were considerably higher than those in non-polluted area. Although dietary intake was the major exposure pathway in the present study, dust ingestion played an important role in this case. Serum PFAAs in local residents was significantly correlated with dust PFAAs levels in their living or working microenvironment. Serum PFAAs and dust PFAAs were significantly higher in family members of occupational workers (FM) than in ordinary residents (OR) (p < 0.01). After a careful analysis of the PFAAs exposure pathway, a potential pathway in addition to direct dust ingestion was suggested: PFAAs might transferred from occupational worker's clothes to dinners via cooking processes. The bioaccumulative potential of PFHxS and PFOS were higher than other PFAAs, which suggested a substantial difference between the bioaccumulative ability of perfluorinated sulfonic acids and perfluorinated carboxylic acids.

  3. The current status of prosthodontic specialists in Japan--the Japan Prosthodontic Society has played an important role in certification of prosthodontic specialists.

    PubMed

    Sato, Hironobu

    2014-07-01

    A board certification system for prosthodontic specialists was established in 2005 by the Japan Prosthodontic Society (JPS), significantly later than the system established by the American Board of Prosthodontics in 1947. The purpose of this study is to outline the certification system for prosthodontic specialists in Japan and discuss and evaluate its current status. In 2012, the number of board certified prosthodontic specialists was 1150 and that of mentorial specialists was 693. The number of board certified institutions was 78 and that of certified adjunct institutions was 23. Although the history of the certification system is not very long, we conclude that a well-organized system has been developed. In addition, prosthodontic departments of dental schools also play an important role in the certification system for prosthodontic specialists.

  4. C-Terminal Di-leucine Motif of Dopamine D1 Receptor Plays an Important Role in Its Plasma Membrane Trafficking

    PubMed Central

    Guo, Yan; Jose, Pedro A.

    2011-01-01

    The dopamine D1 receptor (D1R), a G protein-coupled receptor, plays a critical role in regulating blood pressure through its actions on renal hemodynamics and epithelial ion transport, which are highly linked to its intracellular trafficking. In this study, we generated a series of C-terminal mutants of D1R that were tagged with or without enhanced yellow fluorescent protein, and analyzed the consequences of these mutants on the plasma membrane trafficking of D1R and cyclic AMP response to D1R stimulation. D1R with mutations within the endocytic recycling signal (amino acid residues 360–382) continued to be functional, albeit decreased relative to wild-type D1R. Mutation of the palmitoylation site (347C>S) of D1R did not impair its trafficking to the plasma membrane, but abolished its ability to increase cyclic AMP accumulation. In contrast, replacement of di-leucines (344–345L>A) by alanines resulted in the retention of D1R in the early endosome, decreased its glycosylation, and prevented its targeting to the plasma membrane. Our studies suggest that di-L motif at the C-terminus of D1R is critical for the glycosylation and cell surface targeting of D1R. PMID:22206002

  5. Hemichannels formed by connexin 43 play an important role in the release of prostaglandin E(2) by osteocytes in response to mechanical strain.

    PubMed

    Jiang, Jean X; Cherian, Priscilla P

    2003-01-01

    Osteocytes embedded in the matrix of bone are mechanosensory cells that translate strain into signals and regulate bone remodeling. Our previous studies using osteocyte-like MLO-Y4 cells have shown that fluid flow shear stress (FFSS) increases connexin (Cx) 43 protein expression, prostaglandin E(2) (PGE(2)) release, and intercellular coupling, and PGE(2) is an essential mediator between FFSS and gap junctions. However, the role of Cx43 in the release of PGE(2) in response to FFSS is unknown. Here, the FFSS-loaded MLO-Y4 cells with no or few intercellular channels released significantly more PGE(2) per cell than those cells at higher densities. Antisense Cx43 oligonucleotides and 18 beta-glycyrrhetinic acid, a specific gap junction and hemichannel blocker, significantly reduced PGE(2) release by FFSS at all cell densities tested, especially cells at the lowest density without gap junctions. FFSS, fluid flow-conditioned medium, and PGE(2) increased the activity of dye uptake. Moreover, FFSS induced Cx43 to migrate to the surface of the cell; this surface expressed Cx43 developed resistance to Triton-X-100 solublization. Our results suggest that hemichannels formed by Cx43, instead of intercellular channels, are likely to play a predominant role in the release of intracellular PGE(2) in response to FFSS.

  6. Importance of backbone angles versus amino acid configurations in peptide vibrational Raman optical activity spectra

    NASA Astrophysics Data System (ADS)

    Herrmann, Carmen; Ruud, Kenneth; Reiher, Markus

    2008-01-01

    In this work, we investigate whether the differential scattering of right- and left-circularly polarized light in peptide Raman optical activity spectra are uniquely dominated by the backbone conformation, or whether the configurations of the individual amino acid also play a significant role. This is achieved by calculating Raman optical activity spectra using density functional theory for four structurally related peptides with a common backbone conformation, but with different sequences of amino acid configurations. Furthermore, the ROA signals of the amide normal modes are decomposed into contributions from groups of individual atoms. It is found that the amino acid configuration has a considerable influence on the ROA peaks in the amide I, II, and III regions, although the local decomposition reveals that the side-chain atoms only contribute to those peaks directly in the case of the amide II vibrations. Furthermore, small changes in the amide normal modes may lead to large and irregular modifications in the ROA intensity differences, making it difficult to establish transferable ROA intensity differences even for structurally similar vibrations.

  7. Important amino acid residues of hexachlorocyclohexane dehydrochlorinases (LinA) for enantioselective transformation of hexachlorocyclohexane isomers.

    PubMed

    Shrivastava, Nidhi; Macwan, Ankit S; Kohler, Hans-Peter E; Kumar, Ashwani

    2017-03-01

    LinA-type1 and LinA-type2 are two well-characterized variants of the enzyme 'hexachlorocyclohexane (HCH)-dehydrochlorinase'. They differ from each other at ten amino acid positions and exhibit differing enantioselectivity for the transformation of the (-) and (+) enantiomers of α-HCH. Amino acids responsible for this enantioselectivity, however, are not known. An in silico docking analysis identified four amino acids (K20, L96, A131, and T133) in LinA-type1 that could be involved in selective binding of the substrates. Experimental studies with constructed mutant enzymes revealed that a combined presence of three amino acid changes in LinA-type1, i.e. K20Q, L96C, and A131G, caused a reversal in its preference from the (-) to the (+) enantiomer of α-HCH. This preference was enhanced by the additional amino acid change T133 M. Presence of these four changes also caused the reversal of enantioselectivity of LinA-type1 for δ-HCH, and β-, γ-, and δ-pentachlorocyclohexens. Thus, the residues K20, L96, A131, and T133 in LinA-type1 and the residues Q20, C96, G131, and M133 in LinA-type 2 appear to be important determinants for the enantioselectivity of LinA enzymes.

  8. Molecular cloning and functional analysis of GbRVd, a gene in Gossypium barbadense that plays an important role in conferring resistance to Verticillium wilt.

    PubMed

    Yang, Jun; Ma, Qing; Zhang, Yan; Wang, Xingfen; Zhang, Guiyin; Ma, Zhiying

    2016-01-10

    Most of the disease resistance genes already characterized in plants encode nucleotide-binding site-leucine rich repeat (NBS-LRR) proteins that have key roles in resistance to Verticillium dahliae. Using a cDNA library and RACE protocols, we cloned a coiled-coil (CC)-NBS-LRR-type gene, GbRVd, from a resistant tetraploid cotton species, Gossypium barbadense (RVd=Resistance to V. dahliae). We also applied RT-qPCR and VIGS technologies to analyze how expression of GbRVd was induced upon attack by V. dahliae. Its 2862-bp ORF encodes a predicted protein containing 953 amino acid residues, with a predicted molecular weight of 110.17kDa and an isoelectric point of 5.87. GbRVd has three domains - CC, NBS, and LRR - and is most closely related to Gossypium raimondii RVd (88% amino acid identity). Profiling demonstrated that GbRVd is constitutively expressed in all tested tissues, and transcript levels are especially high in the leaves. In plants inoculated with V. dahliae, GbRVd was significantly up-regulated when compared with the control, with expression peaking at 48h post-inoculation. Silencing of GbRVd in cotton through VIGS dramatically down-regulated SA, NO, and H2O2 production, resulting in greater susceptibility to V. dahliae. Taken together, these results suggest that GbRVd has an important role in protecting G. barbadense against infection by V. dahliae.

  9. GhCFE1A, a dynamic linker between the ER network and actin cytoskeleton, plays an important role in cotton fibre cell initiation and elongation.

    PubMed

    Lv, Fenni; Wang, Haihai; Wang, Xinyu; Han, Libo; Ma, Yinping; Wang, Sen; Feng, Zhidi; Niu, Xiaowei; Cai, Caiping; Kong, Zhaosheng; Zhang, Tianzhen; Guo, Wangzhen

    2015-04-01

    Fibre cell initiation and elongation is critical for cotton fibre development. However, little is known about the regulation of initiation and elongation during fibre cell development. Here, the regulatory role of a novel protein GhCFE1A was uncovered. GhCFE1A is preferentially expressed at initiation and rapid elongation stages during fibre development; in addition, much higher expression of GhCFE1A was detected at the fibre initiation stage in fibreless cotton mutants than in the fibre-bearing TM-1 wild-type. Importantly, overexpression of GhCFE1A in cotton not only delayed fibre cell elongation but also significantly reduced the density of lint and fuzz fibre initials and stem trichomes. Yeast two-hybrid assay showed that GhCFE1A interacted with several actin proteins, and the interaction was further confirmed by co-sedimentation assay. Interestingly, a subcellular localization assay showed that GhCFE1A resided on the cortical endoplasmic reticulum (ER) network and co-localized with actin cables. Moreover, the density of F-actin filaments was shown to be reduced in GhCFE1A-overexpressing fibres at the rapid elongation stage compared with the wild-type control. Taken together, the results demonstrate that GhCFE1A probably functions as a dynamic linker between the actin cytoskeleton and the ER network, and plays an important role in fibre cell initiation and elongation during cotton fibre development.

  10. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization.

    PubMed

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-21

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement.

  11. Proteomics Profiling Reveals Carbohydrate Metabolic Enzymes and 14-3-3 Proteins Play Important Roles for Starch Accumulation during Cassava Root Tuberization

    PubMed Central

    Wang, Xuchu; Chang, Lili; Tong, Zheng; Wang, Dongyang; Yin, Qi; Wang, Dan; Jin, Xiang; Yang, Qian; Wang, Liming; Sun, Yong; Huang, Qixing; Guo, Anping; Peng, Ming

    2016-01-01

    Cassava is one of the most important root crops as a reliable source of food and carbohydrates. Carbohydrate metabolism and starch accumulation in cassava storage root is a cascade process that includes large amounts of proteins and cofactors. Here, comparative proteomics were conducted in cassava root at nine developmental stages. A total of 154 identified proteins were found to be differentially expressed during starch accumulation and root tuberization. Many enzymes involved in starch and sucrose metabolism were significantly up-regulated, and functional classification of the differentially expressed proteins demonstrated that the majority were binding-related enzymes. Many proteins were took part in carbohydrate metabolism to produce energy. Among them, three 14-3-3 isoforms were induced to be clearly phosphorylated during storage root enlargement. Overexpression of a cassava 14-3-3 gene in Arabidopsis thaliana confirmed that the older leaves of these transgenic plants contained higher sugar and starch contents than the wild-type leaves. The 14-3-3 proteins and their binding enzymes may play important roles in carbohydrate metabolism and starch accumulation during cassava root tuberization. These results not only deepened our understanding of the tuberous root proteome, but also uncovered new insights into carbohydrate metabolism and starch accumulation during cassava root enlargement. PMID:26791570

  12. The Stable Level of Glutamine synthetase 2 Plays an Important Role in Rice Growth and in Carbon-Nitrogen Metabolic Balance

    PubMed Central

    Bao, Aili; Zhao, Zhuqing; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

    2015-01-01

    Glutamine synthetase 2 (GS2) is a key enzyme involved in the ammonium metabolism in plant leaves. In our previous study, we obtained GS2-cosuppressed plants, which displayed a normal growth phenotype at the seedling stage, while at the tillering stage they showed a chlorosis phenotype. In this study, to investigate the chlorosis mechanism, we systematically analyzed the plant growth, carbon-nitrogen metabolism and gene expressions between the GS2-cosuppressed rice and wild-type plants. The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems. Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage. The analysis of the metabolic profile showed a significant increase of sugars and organic acids. Additionally, gene expression patterns were different in root and leaf of GS2-cosuppressed plants between the seedling and tillering stage. These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth. PMID:26053400

  13. The Stable Level of Glutamine synthetase 2 Plays an Important Role in Rice Growth and in Carbon-Nitrogen Metabolic Balance.

    PubMed

    Bao, Aili; Zhao, Zhuqing; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

    2015-06-04

    Glutamine synthetase 2 (GS2) is a key enzyme involved in the ammonium metabolism in plant leaves. In our previous study, we obtained GS2-cosuppressed plants, which displayed a normal growth phenotype at the seedling stage, while at the tillering stage they showed a chlorosis phenotype. In this study, to investigate the chlorosis mechanism, we systematically analyzed the plant growth, carbon-nitrogen metabolism and gene expressions between the GS2-cosuppressed rice and wild-type plants. The results revealed that the GS2-cosuppressed plants exhibited a poor plant growth phenotype and a poor nitrogen transport ability, which led to nitrogen accumulation and a decline in the carbon/nitrogen ratio in the stems. Interestingly, there was a higher concentration of soluble proteins and a lower concentration of carbohydrates in the GS2-cosuppressed plants at the seedling stage, while a contrasting result was displayed at the tillering stage. The analysis of the metabolic profile showed a significant increase of sugars and organic acids. Additionally, gene expression patterns were different in root and leaf of GS2-cosuppressed plants between the seedling and tillering stage. These results indicated the important role of a stable level of GS2 transcription during normal rice development and the importance of the carbon-nitrogen metabolic balance in rice growth.

  14. Outdoor Play and Play Equipment.

    ERIC Educational Resources Information Center

    Naylor, Heather

    1985-01-01

    Discusses aspects of the play environment and its effect on children's play behavior. Indoor and outdoor play spaces are considered along with factors affecting the use of outdoor environments for play. Children's preferences for different outdoor play environments and for various play structures are explored. Guides for choosing play equipment…

  15. Characterization of amino acid residues within the N-terminal region of Ubc9 that play a role in Ubc9 nuclear localization

    SciTech Connect

    Sekhri, Palak; Tao, Tao; Kaplan, Feige; Zhang, Xiang-Dong

    2015-02-27

    As the sole E2 enzyme for SUMOylation, Ubc9 is predominantly nuclear. However, the underlying mechanisms of Ubc9 nuclear localization are still not well understood. Here we show that RNAi-depletion of Imp13, an importin known to mediate Ubc9 nuclear import, reduces both Ubc9 nuclear accumulation and global SUMOylation. Furthermore, Ubc9-R13A or Ubc9-H20D mutation previously shown to interrupt the interaction of Ubc9 with nucleus-enriched SUMOs reduces the nuclear enrichment of Ubc9, suggesting that the interaction of Ubc9 with the nuclear SUMOs may enhance Ubc9 nuclear retention. Moreover, Ubc9-R17E mutation, which is known to disrupt the interaction of Ubc9 with both SUMOs and Imp13, causes a greater decrease in Ubc9 nuclear accumulation than Ubc9-R13A or Ubc9-H20D mutation. Lastly, Ubc9-K74A/S89D mutations that perturb the interaction of Ubc9 with nucleus-enriched SUMOylation-consensus motifs has no effect on Ubc9 nuclear localization. Altogether, our results have elucidated that the amino acid residues within the N-terminal region of Ubc9 play a pivotal role in regulation of Ubc9 nuclear localization. - Highlights: • Imp13-mediated nuclear import of Ubc9 is critical for global SUMOylation. • Ubc9 mutations disrupting Ubc9-SUMO interaction decrease Ubc9 nuclear accumulation. • N-terminal amino acid residues of Ubc9 are critical for Ubc9 nuclear enrichment.

  16. Inhibition of nocturnal acidity is important but not essential for duodenal ulcer healing.

    PubMed Central

    Bianchi Porro, G; Parente, F; Sangaletti, O

    1990-01-01

    We have determined the relative importance of day and night time gastric acid inhibition for duodenal ulcer healing by comparing the anti-ulcer efficacy of a single morning with that of a single bedtime dose of ranitidine. One hundred and thirty patients with active duodenal ulcer were randomly assigned to a double-blind therapy with ranitidine 300 mg at 8 am or the same dose at 10 pm for up to eight weeks. The antisecretory effects of these regimens were also assessed by 24 h intragastric pH monitoring in 18 of these patients. At four weeks ulcers had healed in 41/61 (67%) of patients taking the morning dose and in 47/63 (75%) of those receiving the nocturnal dose (95% CI for the difference -0.09 +0.25; p ns). At eight weeks, the corresponding healing rates were 82% and 85.5%, respectively (95% CI for the difference -0.11 +0.17; p ns). Both treatments were significantly superior to placebo in raising 24 h intragastric pH, although the effects of the morning dose were of shorter duration than those of the nocturnal dose. These findings suggest that suppression of nocturnal acidity is important but not essential to promote healing of duodenal ulcers; a prolonged period of acid inhibition during the day (as obtained with a single large morning dose of H2-blockers) may be equally effective. PMID:2186980

  17. β3GnT8 plays an important role in CD147 signal transduction as an upstream modulator of MMP production in tumor cells.

    PubMed

    Jiang, Zhi; Hu, Shuijun; Hua, Dong; Ni, Jianlong; Xu, Lan; Ge, Yan; Zhou, Yinghui; Cheng, Zhihong; Wu, Shiliang

    2014-09-01

    Aberrant carbohydration by related glycosyl-transferases plays an important role in the progression of cancer. This study focused on the ablity of β-1,3-N-acetyl-glucosaminyltransferase-8 (β3GnT8) to regulate MMP-2 expression through regulation of the CD147 signal transduction pathway in cancer cells. β3GnT8 catalyzes and then extends a polylactosamine chain specifically on β1-6-branched tetraantennary N-glycans. CD147 is a major carrier of β1-6-branched polylactosamine sugars on tumor cells, and the high glycoform of CD147 (HG-CD147) induces matrix metalloproteinase (MMP) production. In the present study, we analyzed β3GnT8 mRNA expression in 6 cancer cell lines (MCF-7, M231, LN229, U87, SGC-7901 and U251). We found that β3GnT8 expression in the LN229, SGC-7901 and U251 cell lines was higher than that in the other cell lines. Therefore, we established β3GnT8-knockdown cell lines derived from the LN229 and SGC-7901 cell lines to examine the level of polylactosamine and CD147 N-glycosylation. In addition, tunicamycin is widely used as an inhibitor of N-linked glycosylation. Hence, various concentrations of tunicamycin were used to treat the cells in order to study its influence on CD147 N-glycosylation and MMP-2 expression. In conclusion, we found that β3GnT8 regulated the level of N-glycans on CD147 and that N-glycosylation of CD147 has an important effect on MMP-2 expression. Our findings suggest that β3GnT8 affects the signal transduction pathway of MMP-2 by altering the N-glycan structure of CD147.

  18. Central beta-adrenergic receptors play an important role in the enhancing effect of voluntary exercise on learning and memory in rat.

    PubMed

    Ebrahimi, Shima; Rashidy-Pour, Ali; Vafaei, Abbas A; Akhavan, Maziar M

    2010-03-17

    The beneficial effects of physical activity and exercise on brain functions such as improvement in learning and memory are well documented. The aim of this study was to examine the role of the beta-adrenergic system in voluntary exercise-induced enhancement of learning and memory in rat. In order to block the beta-adrenergic receptors, the animals were received propranolol (a beta-blocker), or nadolol (a peripherally acting beta-blocker) before each night of five consecutive nights of exercise. Then their learning and memory were tested on the water maze task using a two-trials-per-day for 5 consecutive days. A probe trial was performed 2 days after the last training day. Our results showed that propranolol, but not nadolol reversed the exercise-induced improvement in learning and memory in rat. Our findings indicate that central beta-adrenergic receptors play an important role in mediating the beneficial effects of voluntary exercise on learning and memory.

  19. Photorespiration plays an important role in the regulation of photosynthetic electron flow under fluctuating light in tobacco plants grown under full sunlight

    PubMed Central

    Huang, Wei; Hu, Hong; Zhang, Shi-Bao

    2015-01-01

    Plants usually experience dynamic fluctuations of light intensities under natural conditions. However, the responses of mesophyll conductance, CO2 assimilation, and photorespiration to light fluctuation are not well understood. To address this question, we measured photosynthetic parameters of gas exchange and chlorophyll fluorescence in tobacco leaves at 2-min intervals while irradiance levels alternated between 100 and 1200 μmol photons m−2 s−1. Compared with leaves exposed to a constant light of 1200 μmol photons m−2 s−1, both stomatal and mesophyll conductances were significantly restricted in leaves treated with fluctuating light condition. Meanwhile, CO2 assimilation rate and electron flow devoted to RuBP carboxylation at 1200 μmol photons m−2 s−1 under fluctuating light were limited by the low chloroplast CO2 concentration. Analysis based on the C3 photosynthesis model indicated that, at 1200 μmol photons m−2 s−1 under fluctuating light, the CO2 assimilation rate was limited by RuBP carboxylation. Electron flow devoted to RuBP oxygenation at 1200 μmol photons m−2 s−1 under fluctuating light remained at nearly the maximum level throughout the experimental period. We conclude that fluctuating light restricts CO2 assimilation by decreasing both stomatal and mesophyll conductances. Under such conditions, photorespiration plays an important role in the regulation of photosynthetic electron flow. PMID:26322062

  20. Does weather play an important role in the early nesting activity of colonial waterbirds? A case study in putrajaya wetlands, malaysia.

    PubMed

    Ismail, Ahmad; Rahman, Faid

    2013-08-01

    Environmental factors can play important roles in influencing waterbird communities. In particular, weather may have various biological and ecological impacts on the breeding activities of waterbirds, though most studies have investigated the effect of weather on the late stages of waterbird breeding (e.g., hatching rate, chick mortality). Conversely, the present study attempts to highlight the influence of weather on the early nesting activities of waterbirds by evaluating a recently established mixed-species colony in Putrajaya Wetlands, Malaysia. The results show that only rainfall and temperature have a significant influence on the species' nesting activities. Rainfall activity is significantly correlated with the Grey Heron's rate of establishment (rainfall: rs = 0.558, p = 0.03, n = 72) whereas both temperature and rainfall are associated with Painted Stork's nesting density (temperature: rs = 0.573, p = 0.013; rainfall: rs = -0.662, p = 0.03, n = 48). There is a possibility that variations in the rainfall and temperature provide a cue for the birds to initiate their nesting. Regardless, this paper addresses concerns on the limitations faced in the study and suggests long-term studies for confirmation.

  1. Mast cells and histamine play an important role in edema and leukocyte recruitment induced by Potamotrygon motoro stingray venom in mice.

    PubMed

    Kimura, Louise F; Prezotto-Neto, José Pedro; Távora, Bianca C L F; Faquim-Mauro, Eliana L; Pereira, Nicole A; Antoniazzi, Marta M; Jared, Simone G S; Teixeira, Catarina F P; Santoro, Marcelo L; Barbaro, Katia C

    2015-09-01

    This work aimed to investigate mechanisms underlying the inflammatory response caused by Potamotrygon motoro stingray venom (PmV) in mouse paws. Pre-treatment of animals with a mast cell degranulation inhibitor (cromolyn) diminished edema (62% of inhibition) and leukocyte influx into the site of PmV injection. Promethazine (histamine type 1 receptor antagonist) or thioperamide (histamine type 3 and 4 receptor antagonist) also decreased edema (up to 30%) and leukocyte numbers, mainly neutrophils (40-50 %). Cimetidine (histamine type 2 receptor antagonist) had no effect on PmV-induced inflammation. In the RBL-2H3 lineage of mast cells, PmV caused proper cell activation, in a dose-dependent manner, with release of PGD2 and PGE2. In addition, the role of COXs products on PmV inflammatory response was evaluated. Indomethacin (COX-1/COX-2 inhibitor) or etoricoxib (COX-2 inhibitor) partially diminished edema (around 20%) in PmV-injected mice. Indomethacin, but not etoricoxib, modulated neutrophil influx into the site of venom injection. In conclusion, mast cell degranulation and histamine, besides COXs products, play an important role in PmV-induced reaction. Since PmV mechanism of action remains unknown, hindering accurate treatment, clinical studies can be performed to validate the prescription of antihistaminic drugs, besides NSAIDs, to patients injured by freshwater stingrays.

  2. cDNA-AFLP analysis reveals heat shock proteins play important roles in mediating cold, heat, and drought tolerance in Ammopiptanthus mongolicus.

    PubMed

    Guo, Huiming; Li, Zhaochun; Zhou, Meiliang; Cheng, Hongmei

    2014-03-01

    Ammopiptanthus mongolicus (Maxim.ex kom.) Cheng F. is the only evergreen broadleaf shrub endemic to the desert of central Asian and it can survive at drought, salt, and alkali stress. It is believed that A. mongolicus is an important germplasm containing abiotic-tolerance genes. In order to identify drought-, cold-, and heat-responsive genes and to gain a better understanding of stress responses in A. mongolicus, genome-wide investigation of drought-, cold-, and heat-responsive genes was performed in A. mongolicus using cDNA-amplified fragment length polymorphism. Selective amplification with 240 primer combinations generated 5,000 differentially expressed transcript derived fragments (TDFs). Of these, 201 TDFs with differential expression patterns were excised from gels, reamplified by PCR, and sequenced. The gene expression patterns of 11 regulated genes were further investigated by semiquantitative reverse transcriptase polymerase chain reaction analysis. Sequencing and similarity analysis revealed that TDFs present homologies chiefly with proteins involved in various abiotic and biotic stress and developmental responses. The information presented in this study reveals that heat shock proteins play an active role in mediating drought, cold, and heat tolerance in A. mongolicus.

  3. Rho-Associated Protein Kinases Play an Important Role in the Differentiation of Rat Adipose-Derived Stromal Cells into Cardiomyocytes In Vitro

    PubMed Central

    Zhao, Lili; Yang, Gongshe; Zhao, Xin

    2014-01-01

    Adipose-derived stromal cells (ADSCs) represent a readily available abundant supply of mesenchymal stem cells and have the ability to differentiate into cardiomyocytes in mice and human, making ADSCs a promising source of cardiomyocytes for transplantation. However, there has been no report of differentiation of rat ADSCs into cardiomyocytes. In addition, signaling pathways in the differentiation process from ADSCs to cardiomyocytes are unknown. In this study, we first demonstrated that rat ADSCs spontaneously differentiated into cardiomyocytes in vitro, when cultured on a complete medium formulation MethoCult GF M3534. These differentiated cells possessed cardiomyocyte phenotype and expressed cardiac markers. Moreover, these cells showed open excitation-contracting coupling and Ca2+ transient and contracted spontaneously. The role of Rho-associated protein kinases (ROCKs) in the differentiation process was then studied by using ROCK-specific inhibitor Y-27632 and ROCK siRNAs. These agents changed the arrangement of cytoskeleton and diminished appearance of cardiomyocyte phenotype, accompanied by inhibition of c-Jun N-terminal kinase (JNK) phosphorylation and promotion of Akt phosphorylation. Collectively, this is the first study to demonstrate that rat ADSCs could spontaneously differentiate into cardiomyocytes in vitro and ROCKs play an important role in the differentiation of ADSCs into beating cardiomyocytes in conjunction of the PI3K/Akt pathway and the JNK pathway. PMID:25522345

  4. RUNX3 plays an important role in As2O3‑induced apoptosis and allows cells to overcome MSC‑mediated drug resistance.

    PubMed

    Pan, Guo-Zheng; Zhai, Feng-Xian; Lu, Yin; Fang, Zhi-Gang; Fan, Rui-Fang; Liu, Xiang-Fu; Lin, Dong-Jun

    2016-10-01

    The interaction between bone marrow stromal cells and leukemia cells is critical for the persistence and progression of leukemia, and this interaction may account for residual disease. However, the link between leukemia cells and their environment is still poorly understood. In our study, runt‑related transcription factor 3 (RUNX3) was identified as a novel target gene affected by As2O3 and involved in mesenchymal stem cell (MSC)‑mediated protection of leukemia cells from As2O3‑induced apoptosis. We observed induction of RUNX3 expression and the translocation of RUNX3 into the nucleus after As2O3 treatment in leukemia cells. In K562 chronic myeloid leukemia cells, downregulation of endogenous RUNX3 compromised As2O3‑induced growth inhibition, cell cycle arrest, and apoptosis. In the presence of MSC, As2O3‑induced expression of RUNX3 was reduced significantly and this reduction was modulated by CXCL12/CXCR4 signaling. Furthermore, overexpression of RUNX3 restored, at least in part, the sensitivity of leukemic cells to As2O3. We conclude that RUNX3 plays an important role in As2O3‑induced cellular responses and allows cells to overcome MSC‑mediated drug resistance. Therefore, RUNX3 is a promising target for therapeutic approaches to overcome MSC‑mediated drug resistance.

  5. Photorespiration plays an important role in the regulation of photosynthetic electron flow under fluctuating light in tobacco plants grown under full sunlight.

    PubMed

    Huang, Wei; Hu, Hong; Zhang, Shi-Bao

    2015-01-01

    Plants usually experience dynamic fluctuations of light intensities under natural conditions. However, the responses of mesophyll conductance, CO2 assimilation, and photorespiration to light fluctuation are not well understood. To address this question, we measured photosynthetic parameters of gas exchange and chlorophyll fluorescence in tobacco leaves at 2-min intervals while irradiance levels alternated between 100 and 1200 μmol photons m(-2) s(-1). Compared with leaves exposed to a constant light of 1200 μmol photons m(-2) s(-1), both stomatal and mesophyll conductances were significantly restricted in leaves treated with fluctuating light condition. Meanwhile, CO2 assimilation rate and electron flow devoted to RuBP carboxylation at 1200 μmol photons m(-2) s(-1) under fluctuating light were limited by the low chloroplast CO2 concentration. Analysis based on the C3 photosynthesis model indicated that, at 1200 μmol photons m(-2) s(-1) under fluctuating light, the CO2 assimilation rate was limited by RuBP carboxylation. Electron flow devoted to RuBP oxygenation at 1200 μmol photons m(-2) s(-1) under fluctuating light remained at nearly the maximum level throughout the experimental period. We conclude that fluctuating light restricts CO2 assimilation by decreasing both stomatal and mesophyll conductances. Under such conditions, photorespiration plays an important role in the regulation of photosynthetic electron flow.

  6. The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus.

    PubMed

    Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-Hua; Chai, Yunrong

    2016-01-01

    Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species.

  7. A complex of Cox4 and mitochondrial Hsp70 plays an important role in the assembly of the cytochrome c oxidase

    PubMed Central

    Böttinger, Lena; Guiard, Bernard; Oeljeklaus, Silke; Kulawiak, Bogusz; Zufall, Nicole; Wiedemann, Nils; Warscheid, Bettina; van der Laan, Martin; Becker, Thomas

    2013-01-01

    The formation of the mature cytochrome c oxidase (complex IV) involves the association of nuclear- and mitochondria-encoded subunits. The assembly of nuclear-encoded subunits like cytochrome c oxidase subunit 4 (Cox4) into the mature complex is poorly understood. Cox4 is crucial for the stability of complex IV. To find specific biogenesis factors, we analyze interaction partners of Cox4 by affinity purification and mass spectroscopy. Surprisingly, we identify a complex of Cox4, the mitochondrial Hsp70 (mtHsp70), and its nucleotide-exchange factor mitochondrial GrpE (Mge1). We generate a yeast mutant of mtHsp70 specifically impaired in the formation of this novel mtHsp70-Mge1-Cox4 complex. Strikingly, the assembly of Cox4 is strongly decreased in these mutant mitochondria. Because Cox4 is a key factor for the biogenesis of complex IV, we conclude that the mtHsp70-Mge1-Cox4 complex plays an important role in the formation of cytochrome c oxidase. Cox4 arrests at this chaperone complex in the absence of mature complex IV. Thus the mtHsp70-Cox4 complex likely serves as a novel delivery system to channel Cox4 into the assembly line when needed. PMID:23864706

  8. The comER Gene Plays an Important Role in Biofilm Formation and Sporulation in both Bacillus subtilis and Bacillus cereus

    PubMed Central

    Yan, Fang; Yu, Yiyang; Wang, Luyao; Luo, Yuming; Guo, Jian-hua; Chai, Yunrong

    2016-01-01

    Bacteria adopt alternative cell fates during development. In Bacillus subtilis, the transition from planktonic growth to biofilm formation and sporulation is controlled by a complex regulatory circuit, in which the most important event is activation of Spo0A, a transcription factor and a master regulator for genes involved in both biofilm formation and sporulation. In B. cereus, the regulatory pathway controlling biofilm formation and cell differentiation is much less clear. In this study, we show that a novel gene, comER, plays a significant role in biofilm formation as well as sporulation in both B. subtilis and B. cereus. Mutations in the comER gene result in defects in biofilm formation and a delay in spore formation in the two Bacillus species. Our evidence supports the idea that comER may be part of the regulatory circuit that controls Spo0A activation. comER likely acts upstream of sda, a gene encoding a small checkpoint protein for both sporulation and biofilm formation, by blocking the phosphor-relay and thereby Spo0A activation. In summary, our studies outlined a conserved, positive role for comER, a gene whose function was previously uncharacterized, in the regulation of biofilm formation and sporulation in the two Bacillus species. PMID:27446060

  9. The Interrelationship between Abscisic Acid and Reactive Oxygen Species Plays a Key Role in Barley Seed Dormancy and Germination

    PubMed Central

    Ishibashi, Yushi; Aoki, Nozomi; Kasa, Shinsuke; Sakamoto, Masatsugu; Kai, Kyohei; Tomokiyo, Reisa; Watabe, Gaku; Yuasa, Takashi; Iwaya-Inoue, Mari

    2017-01-01

    Seed dormancy is one of the adaptive responses in the plant life cycle and an important agronomic trait. Reactive oxygen species (ROS) release seed dormancy and promote seed germination in several cereal crops; however, the key regulatory mechanism of ROS-mediated seed dormancy and germination remains controversial. Here, we focused on the relationship between hydrogen peroxide (a ROS) and abscisic acid (ABA) in dormant and non-dormant barley seeds. The hydrogen peroxide (H2O2) level produced in barley seed embryos after imbibition was higher in non-dormant seeds than in dormant seeds. H2O2 regulated the ABA content in the embryos through ABA-8′-hydroxylase, an ABA catabolic enzyme. Moreover, compared with non-dormant seeds, in dormant seeds the activity of NADPH oxidase, which produces ROS, was lower, whereas the activity of catalase, which is a H2O2 scavenging enzyme, was higher, as was the expression of HvCAT2. Furthermore, precocious germination of isolated immature embryos was suppressed by the transient introduction of HvCAT2 driven by the maize (Zea mays) ubiquitin promoter. HvCAT2 expression was regulated through an ABA-responsive transcription factor (HvABI5) induced by ABA. These results suggest that the changing of balance between ABA and ROS is active in barley seed embryos after imbibition and regulates barley seed dormancy and germination. PMID:28377774

  10. The Interrelationship between Abscisic Acid and Reactive Oxygen Species Plays a Key Role in Barley Seed Dormancy and Germination.

    PubMed

    Ishibashi, Yushi; Aoki, Nozomi; Kasa, Shinsuke; Sakamoto, Masatsugu; Kai, Kyohei; Tomokiyo, Reisa; Watabe, Gaku; Yuasa, Takashi; Iwaya-Inoue, Mari

    2017-01-01

    Seed dormancy is one of the adaptive responses in the plant life cycle and an important agronomic trait. Reactive oxygen species (ROS) release seed dormancy and promote seed germination in several cereal crops; however, the key regulatory mechanism of ROS-mediated seed dormancy and germination remains controversial. Here, we focused on the relationship between hydrogen peroxide (a ROS) and abscisic acid (ABA) in dormant and non-dormant barley seeds. The hydrogen peroxide (H2O2) level produced in barley seed embryos after imbibition was higher in non-dormant seeds than in dormant seeds. H2O2 regulated the ABA content in the embryos through ABA-8'-hydroxylase, an ABA catabolic enzyme. Moreover, compared with non-dormant seeds, in dormant seeds the activity of NADPH oxidase, which produces ROS, was lower, whereas the activity of catalase, which is a H2O2 scavenging enzyme, was higher, as was the expression of HvCAT2. Furthermore, precocious germination of isolated immature embryos was suppressed by the transient introduction of HvCAT2 driven by the maize (Zea mays) ubiquitin promoter. HvCAT2 expression was regulated through an ABA-responsive transcription factor (HvABI5) induced by ABA. These results suggest that the changing of balance between ABA and ROS is active in barley seed embryos after imbibition and regulates barley seed dormancy and germination.

  11. Structure of a Bacterial ABC Transporter Involved in the Import of an Acidic Polysaccharide Alginate.

    PubMed

    Maruyama, Yukie; Itoh, Takafumi; Kaneko, Ai; Nishitani, Yu; Mikami, Bunzo; Hashimoto, Wataru; Murata, Kousaku

    2015-09-01

    The acidic polysaccharide alginate represents a promising marine biomass for the microbial production of biofuels, although the molecular and structural characteristics of alginate transporters remain to be clarified. In Sphingomonas sp. A1, the ATP-binding cassette transporter AlgM1M2SS is responsible for the import of alginate across the cytoplasmic membrane. Here, we present the substrate-transport characteristics and quaternary structure of AlgM1M2SS. The addition of poly- or oligoalginate enhanced the ATPase activity of reconstituted AlgM1M2SS coupled with one of the periplasmic solute-binding proteins, AlgQ1 or AlgQ2. External fluorescence-labeled oligoalginates were specifically imported into AlgM1M2SS-containing proteoliposomes in the presence of AlgQ2, ATP, and Mg(2+). The crystal structure of AlgQ2-bound AlgM1M2SS adopts an inward-facing conformation. The interaction between AlgQ2 and AlgM1M2SS induces the formation of an alginate-binding tunnel-like structure accessible to the solvent. The translocation route inside the transmembrane domains contains charged residues suitable for the import of acidic saccharides.

  12. Organic anion-transporting polypeptide 1a4 (Oatp1a4) is important for secondary bile acid metabolism

    PubMed Central

    Zhang, Youcai; Csanaky, Iván L.; Selwyn, Felcy Pavithra; Lehman-McKeeman, Lois D.; Klaassen, Curtis D.

    2013-01-01

    Organic anion transporting polypeptides (human: OATPs; rodent: Oatps) were thought to have important functions in bile acid (BA) transport. Oatp1a1, 1a4, and 1b2 are the three major Oatp1 family members in rodent liver. Our previous studies have characterized the BA homeostasis in Oatp1a1-null and Oatp1b2-null mice. The present study investigated the physiological role of Oatp1a4 in BA homeostasis by using Oatp1a4-null mice. Oatp1a4 expression is female-predominant in livers of mice, and thereby it was expected that female Oatp1a4-null mice will have more prominent changes than males. Interestingly, the present study demonstrated that female Oatp1a4-null mice had no significant alterations in BA concentrations in serum or liver, though they had increased mRNA of hepatic BA efflux transporters (Mrp4 and Ostα/β) and ileal BA transporters (Asbt and Ostα/β). In contrast, male Oatp1a4-null mice showed significantly altered BA homeostasis, including increased concentrations of deoxycholic acid (DCA) in serum, liver and intestinal contents. After feeding a DCA-supplemented diet, male but not female Oatp1a4-null mice had higher concentrations of DCA in serum and livers than their WT controls. This suggested that Oatp1a4 is important for intestinal absorption of secondary BAs in male mice. Furthermore, loss of Oatp1a4 function did not decrease BA accumulation in serum or livers of bile-ductligated mice, suggesting that Oatp1a4 is not likely a BA uptake transporter. In summary, the present study for the first time demonstrates that Oatp1a4 does not appear to mediate the hepatic uptake of BAs, but plays an important male-predominant role in secondary BA metabolism in mice. PMID:23747753

  13. The mitochondrial protein import component, TRANSLOCASE OF THE INNER MEMBRANE17-1, plays a role in defining the timing of germination in Arabidopsis.

    PubMed

    Wang, Yan; Law, Simon R; Ivanova, Aneta; van Aken, Olivier; Kubiszewski-Jakubiak, Szymon; Uggalla, Vindya; van der Merwe, Margaretha; Duncan, Owen; Narsai, Reena; Whelan, James; Murcha, Monika W

    2014-11-01

    In Arabidopsis (Arabidopsis thaliana), small gene families encode multiple isoforms for many of the components of the mitochondrial protein import apparatus. There are three isoforms of the TRANSLOCASE OF THE INNER MEMBRANE17 (Tim17). Transcriptome analysis indicates that AtTim17-1 is only detectable in dry seed. In this study, two independent transfer DNA insertional mutant lines of tim17-1 exhibited a germination-specific phenotype, showing a significant increase in the rate of germination. Microarray analyses revealed that Attim17-1 displayed alterations in the temporal sequence of transcriptomic events during germination, peaking earlier compared with the wild type. Promoter analysis of AtTim17-1 further identified an abscisic acid (ABA)-responsive element, which binds ABA-responsive transcription factors, acting to repress the expression of AtTim17-1. Attim17-1 dry seeds contained significantly increased levels of ABA and gibberellin, 2- and 5-fold, respectively. These results support the model that mitochondrial biogenesis is regulated in a tight temporal sequence of events during germination and that altering mitochondrial biogenesis feeds back to alter the germination rate, as evidenced by the altered levels of the master regulatory hormones that define germination.

  14. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alexander

    A philosophical analysis of play and games is undertaken in this paper. Playful gaming, which is shown to be a synthesis of play and games, is utilized as a category for undertaking the examination of play and games. The significance of playful gaming to education is demonstrated through analyses of Plato's, Dewey's, Sartre's, and Marcuse's…

  15. Heat tolerance plays an important role in regulating remontant flowering in an F1 population of octoploid strawberry (Fragaria ×ananassa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    BACKGROUND: Flower initiation in strawberry is often classified by photoperiod sensitivity; however, temperature also plays a major role in determining flower initiation. OBJECTIVE: Our goal was to determine the role heat tolerance plays in regulating remontant flowering in a segregating population ...

  16. Prediction of functionally important residues in globular proteins from unusual central distances of amino acids

    PubMed Central

    2011-01-01

    Background Well-performing automated protein function recognition approaches usually comprise several complementary techniques. Beside constructing better consensus, their predictive power can be improved by either adding or refining independent modules that explore orthogonal features of proteins. In this work, we demonstrated how the exploration of global atomic distributions can be used to indicate functionally important residues. Results Using a set of carefully selected globular proteins, we parametrized continuous probability density functions describing preferred central distances of individual protein atoms. Relative preferred burials were estimated using mixture models of radial density functions dependent on the amino acid composition of a protein under consideration. The unexpectedness of extraordinary locations of atoms was evaluated in the information-theoretic manner and used directly for the identification of key amino acids. In the validation study, we tested capabilities of a tool built upon our approach, called SurpResi, by searching for binding sites interacting with ligands. The tool indicated multiple candidate sites achieving success rates comparable to several geometric methods. We also showed that the unexpectedness is a property of regions involved in protein-protein interactions, and thus can be used for the ranking of protein docking predictions. The computational approach implemented in this work is freely available via a Web interface at http://www.bioinformatics.org/surpresi. Conclusions Probabilistic analysis of atomic central distances in globular proteins is capable of capturing distinct orientational preferences of amino acids as resulting from different sizes, charges and hydrophobic characters of their side chains. When idealized spatial preferences can be inferred from the sole amino acid composition of a protein, residues located in hydrophobically unfavorable environments can be easily detected. Such residues turn out to be

  17. Cyclooxygenase-2 derived PGE2 and PGI2 play an important role via EP2 and PPARdelta receptors in early steps of oil induced decidualization in mice.

    PubMed

    Pakrasi, P L; Jain, A K

    2008-06-01

    Differentiation of endometrial stromal cells into decidual cells (decidualization) is prerequisite for blastocyst implantation. Different prostanoids are shown to be involved in the cascade of events found in implantation and decidualization. Previous reports described that cyclooxygenase-2 (COX2) derived prostacyclin (PGI2) plays an important role via peroxisome proliferator activated receptor (PPARdelta) nuclear receptor in implantation and decidualization. Herein, we investigated the role of COX2 derived PGE2 and PGI2 and examined the protein expression and regulation of COX1, COX2, membrane-bound prostaglandin E synthase (mPGES-1), prostaglandin I synthase (PGIS), PGE2 receptor (EP2) and PPARdelta in hormone primed oil infused uterine horn as well as in non-infused uterine horn (control horn). Our results show that selective COX2 inhibitor (Nimesulide) inhibits decidualization while COX1 inhibitor (SC560) does not affect decidualization. COX2, mPGES-1, PGIS, EP2 and PPARdelta immunostaining are strongly observed at 24 h and 48 h in oil-induced horn and than significantly reduced at 72 h and 120 h and absent in non-infused horn. However COX1 immunostaining is observed in infused as well as in non-infused horn. Our immunohistochemical studies corroborated well with follow up western blotting of the same proteins. PGE2 and PGI2 products were also elevated at 24h and 48 h after oil induction in infused horn in comparison to control horn. Our data suggest that COX2 derived both PGE2 and PGI2 mediate its function via EP2 and PPARdelta receptors in early steps of decidualization in mice.

  18. Calpain, Atg5 and Bak play important roles in the crosstalk between apoptosis and autophagy induced by influx of extracellular calcium.

    PubMed

    Shi, Mei; Zhang, Tian; Sun, Lei; Luo, Yan; Liu, De-Hua; Xie, Shu-Tao; Song, Xiao-Yan; Wang, Guo-Fan; Chen, Xiu-Lan; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-04-01

    Calcium (Ca(2+)) signals are involved in important checkpoints in cell death pathways and promote both apoptosis and autophagy. However, the relationship between autophagy and apoptosis in response to Ca(2+) level elevation is poorly understood. Here, we provided evidence that the influx of extracellular Ca(2+) triggered by Trichokonin VI (TK VI), an antimicrobial peptide, induced calpain-dependent apoptosis and autophagy in hepatocellular carcinoma (HCC) cells. Remarkably, TK VI preferentially induced apoptosis that was associated with calpain-mediated Bax and Atg5 cleavage, which resulted in the collapse of the mitochondrial membrane potential and cytochrome c release. Interestingly, truncated, but not full-length Atg5, associated with Bcl-xL and promoted the intrinsic pathway. Moreover, TK VI treatment induced reactive oxygen species (ROS) accumulation, an effect in which Bak might play a major role. This accumulation of ROS resulted in the subsequent disposal of damaged mitochondria within autophagosomes via Atg5-mediated and mitochondria-selective autophagy. Both the inhibition of calpain activity and Bax deficiency activated a switch that promoted an enhancement of autophagy. The inhibition of both apoptosis and autophagy significantly attenuated the TK VI cytotoxicity, indicating that the two processes had stimulatory effects during TK VI-meditated cell death. These results suggested that calpain, Bak and Atg5 were molecular links between autophagy and apoptosis and revealed novel aspects of the crosstalk between these two processes. The potential of TK VI is proposed as a promising anticancer agent for its well-characterized activity of Ca(2+) agonist and as a possible novel therapeutic strategy that acts on cancer cell mitochondria.

  19. hsp90 and hsp47 appear to play an important role in minnow Puntius sophore for surviving in the hot spring run-off aquatic ecosystem.

    PubMed

    Mahanty, Arabinda; Purohit, Gopal Krishna; Yadav, Ravi Prakash; Mohanty, Sasmita; Mohanty, Bimal Prasanna

    2017-02-01

    Changes in the expression of a number of hsp genes in minnow Puntius sophore collected from a hot spring run-off (Atri hot spring in Odisha, India; 20(o)09'N 85(°)18'E, 36-38 °C) were investigated to study the upper thermal acclimation response under heat stress, using same species from aquaculture ponds (water temperature 27 °C) as control. Expression of hsp genes was analyzed in both groups using RT-qPCR, which showed up-regulation of hsp90 (2.1-fold) and hsp47 (2.5-fold) in hot spring run-off fishes, whereas there was no alteration in expression of other hsps. As the fish inhabit the hot spring run-off area for very long duration, they could have adapted to the environment. To test this hypothesis, fishes collected from hot spring run-off were divided into two groups; one was heat-shocked at 41 °C/24 h, and the other was acclimatized at 27 °C/24 h. Up-regulation of all the hsps (except hsp78) was observed in the heat-shocked fishes, whereas expression of all hsps was found to be down-regulated to the basal level in fishes maintained at 27 °C/24 h. Pathway analysis showed that the expressions of all the hsps except hsp90 are regulated by the transcription factor heat shock factor 1 (Hsf1). This study showed that hsp90 and hsp47 play an important role in Puntius sophore for surviving in the high-temperature environment of the hot spring run-off. Additionally, we show that plasticity in hsp gene expression is not lost in the hot spring run-off population.

  20. The interleukin-2 receptor α chain (CD25) plays an important role in regulating monocyte-derived CD40 expression during anti-porcine cellular responses.

    PubMed

    Sun, Z-G; Wang, Z; Zhu, L-M; Fang, Y-S; Yu, L-Z; Xu, H

    2012-05-01

    Long-term xenograft survival is limited by delayed xenograft rejection, and monocytes are thought to play an important role in this process. Although typically considered a T cell surface marker, interleukin 2 the receptor chain CD25 is also functional on monocytes. We hypothesized that CD25 expression on monocytes functions to augment monocyte activation in xeno-specific cellular responses. Xenogeneic mixed lymphocyte-endothelial cell reactions were used to study the role of CD25 in facilitating xenogeneic cell-mediated immune responses an in vitro. We also tested the effect of the anti-CD25 antibody daclizumab on monocyte-mediated T cell activation during xeno-specific cellular responses. Co-culture with porcine endothelial cells (PEC) elicited a pronounced proliferative response by human peripheral blood mononuclear cells (PBMC) that was accompanied by upregulation of CD25 and CD40 on CD14(+) monocytes. CD4(+) cells proliferated in response to PEC-conditioned monocytes, while blockade of CD25 with daclizumab reduced CD4(+) cell proliferation in the presence of PEC-conditioned monocytes. In addition, daclizumab inhibited proliferation of PBMC in responses to PEC. Analysis of monocytes from PBMC-PEC cocultures by flow cytometry indicated that daclizumab inhibited CD40 upregulation on PEC-activated monocytes. These data demonstrate that CD25 blockade prevents xenogeneic cellular responses by directly blocking CD25 expression on both activated T cells and monocytes. CD25 blockade on T cells or monocytes may indirectly affect upregulation of CD40 on xenoreactive monocytes. Our data strengthen the rationale for incorporating CD25 directed therapy in discordant xenotransplantation.

  1. TLR9 played a more important role than TLR2 in the combination of maltose-binding protein and BCG-induced Th1 activation.

    PubMed

    Ni, Weihua; Wang, Fang; Liu, Guomu; Zhang, Nannan; Yuan, Hongyan; Jie, Jing; Tai, Guixiang

    2016-11-01

    Our previous study demonstrated that maltose-binding protein (MBP) combined with BCG induced synergistic mouse Th1 activation in vivo. Here, to explore the mechanism of MBP combined with BCG on Th1 activation, mouse purified CD4(+) T cells were stimulated with MBP and BCG in vitro. The results showed that MBP combined with BCG synergistically increased IFN-γ production, accompanied with the upregulation of TLR2/9 expressions, suggesting that TLR2/9 were involved in the combination-induced Th1 activation. Next, TLR2 antibodies and TLR9 inhibitor were used to further analyze the effects of TLRs in Th1 activation. Results showed TLR2 antibody partly decreased MBP combined with BCG-induced IFN-γ production, MyD88 expression and IκB phosphorylation, indicating that TLR2-mediated MyD88-dependent pathway was involved in the MBP combined with BCG-induced Th1 activation. Moreover, MBP combined with BCG-induced Th1 activation was completely abrogated by TLR9 inhibitor, suggesting that TLR9-mediated MyD88-dependent pathway played a more important role than TLR2 in the combination-induced Th1 activation. Further study showed that TLR9 inhibitor downregulated TLR2 expression, suggesting that TLR9 signaling regulated TLR2 activation to favor Th1 resonse induced by MBP combined with BCG. Collectively, we demonstrated for the first time that the cross-talk of TLR2 and TLR9 triggered Th1 activation collaboratively and our findings provided valuable information about designing more effective adjuvant for cancer therapy.

  2. Mutagenesis of conserved amino acids of Helicobacter pylori fur reveals residues important for function.

    PubMed

    Carpenter, Beth M; Gancz, Hanan; Benoit, Stéphane L; Evans, Sarah; Olsen, Cara H; Michel, Sarah L J; Maier, Robert J; Merrell, D Scott

    2010-10-01

    The ferric uptake regulator (Fur) of the medically important pathogen Helicobacter pylori is unique in that it has been shown to function as a repressor both in the presence of an Fe2+ cofactor and in its apo (non-Fe2+-bound) form. However, virtually nothing is known concerning the amino acid residues that are important for Fur functioning. Therefore, mutations in six conserved amino acid residues of H. pylori Fur were constructed and analyzed for their impact on both iron-bound and apo repression. In addition, accumulation of the mutant proteins, protein secondary structure, DNA binding ability, iron binding capacity, and the ability to form higher-order structures were also examined for each mutant protein. While none of the mutated residues completely abrogated the function of Fur, we were able to identify residues that were critical for both iron-bound and apo-Fur repression. One mutation, V64A, did not alter regulation of any target genes. However, each of the five remaining mutations showed an effect on either iron-bound or apo regulation. Of these, H96A, E110A, and E117A mutations altered iron-bound Fur regulation and were all shown to influence iron binding to different extents. Additionally, the H96A mutation was shown to alter Fur oligomerization, and the E110A mutation was shown to impact oligomerization and DNA binding. Conversely, the H134A mutant exhibited changes in apo-Fur regulation that were the result of alterations in DNA binding. Although the E90A mutant exhibited alterations in apo-Fur regulation, this mutation did not affect any of the assessed protein functions. This study is the first for H. pylori to analyze the roles of specific amino acid residues of Fur in function and continues to highlight the complexity of Fur regulation in this organism.

  3. Evaluation of liver fibrosis in patients with thalassemia: the important role of hyaluronic acid.

    PubMed

    Papastamataki, Maria; Delaporta, Polyxeni; Premetis, Evangelos; Kattamis, Antonios; Ladis, Vassilios; Papassotiriou, Ioannis

    2010-10-15

    Patients with transfusion-dependent thalassemia major often develop liver fibrosis due to liver iron overload and/or hepatitis virus C (HCV) infection. Hyaluronic acid (HA) plays a prominent role in the pathogenesis of liver fibrosis and the elevation of serum HA concentration is due to either increased synthesis by inflammatory cells and hepatic stellate cells or impaired degradation by sinusoidal endothelial cells (SECs) and thus is proposed as a non-invasive biomarker of liver fibrosis either by itself and/or included in the Hepascore formula. In this study we evaluated prospectively a screening of liver fibrosis in 201 adult patients aged 19-54 years with transfusion-dependent thalassemia major, based on HA measurements. 41/201 patients were HCV-RNA (+). HA was measured with a turbidimetric assay applied on a clinical chemistry analyzer. The Hepascore was computed from the results by using the model previously published. The main results of the study showed that: a) HA levels were increased in 110/201 (55%) thalassemia patients 85.0 ± 10.3 ng/ml, ranged from 15.0 to 1495.0 μg/l, compared to 20.8 ± 7.4 μg/l reference laboratory values, p<0.001, b) HA levels were significantly higher in HCV-RNA(+) compared to HCV-RNA(-) patients, 171.6 ± 202 vs 53.8 ± 35.5 μg/l, p<0.0001 c) no significant correlations were found between HA levels and/or Hepascore with ferritin and liver iron content (LIC) assessed with MRI (p>0.324 and p>0.270, respectively). Our findings indicate that hyaluronic acid measurements contribute to the assessment of liver fibrosis in patients with thalassemia and might be helpful for further evaluation of patients with liver biopsy if this is truly needed. Furthermore, liver fibrosis in thalassemia seems to be independent from liver siderosis.

  4. A novel formaldehyde metabolic pathway plays an important role during formaldehyde metabolism and detoxification in tobacco leaves under liquid formaldehyde stress.

    PubMed

    Wang, Ru; Zeng, Zhidong; Liu, Ting; Liu, Ang; Zhao, Yan; Li, Kunzhi; Chen, Limei

    2016-08-01

    Tobacco and Arabidopsis are two model plants often used in botany research. Our previous study indicated that the formaldehyde (HCHO) uptake and assimilation capacities of tobacco leaves were weaker than those of Arabidopsis leaves. After treatment with a 2, 4 or 6 mM HCHO solution for 24 h, detached tobacco leaves absorbed approximately 40% of the HCHO from the treatment solution. (13)C-NMR analysis detected a novel HCHO metabolic pathway in 2 mM H(13)CHO-treated tobacco leaves. [4-(13)C]Asn, [3-(13)C]Gln and [U-(13)C]oxalic acid (OA) were produced from this pathway after H(13)COOH generation during H(13)CHO metabolism in tobacco leaves. Pretreatments of cyclosporin A (CSA) and dark almost completely inhibited the generation of [4-(13)C]Asn, [3-(13)C]Gln and [U-(13)C]OA from this pathway but did not suppressed the production of H(13)COOH in 2 mM H(13)CHO-treated tobacco leaves. The evidence suggests that this novel pathway has an important role during the metabolic detoxification of HCHO in tobacco leaves. The analysis of the chlorophyll and Rubisco contents indicated that CSA and dark pretreatments did not severely affect the survival of leaf cells but significantly inhibited the HCHO uptake by tobacco leaves. Based on the effects of CSA and dark pretreatments on HCHO uptake and metabolism, it is estimated that the contribution of this novel metabolic pathway to HCHO uptake is approximately 60%. The data obtained from the (13)C-NMR analysis revealed the mechanism underlying the weaker HCHO uptake and assimilation of tobacco leaves compared to Arabidopsis leaves.

  5. The subunit gene Ldα1 of nicotinic acetylcholine receptors plays important roles in the toxicity of imidacloprid and thiamethoxam against Leptinotarsa decemlineata.

    PubMed

    Qu, Yang; Chen, Jinhua; Li, Chenge; Wang, Qiang; Guo, Wenchao; Han, Zhaojun; Jiang, Weihua

    2016-02-01

    Nicotinic acetylcholine receptors (nAChRs) are pentameric ACh-gated ion channels. It is believed that nAChRs composed of different subunits may vary in their function and toxicological characteristics. Neonicotinoids are activators of nAChRs and important insecticides that are extensively used for crop protection and resistance has been developed by some pests. They are also major insecticides for the control of Leptinotarsa decemlineata, which is a destructive defoliator pest that invaded the Xinjiang region of China in the 1990s. However, little is known about the constitution or subunits of the target in this pest. In this study, the full-length cDNAs encoding four new nAChR subunits (named Ldα3, Ldα6, Ldα10, and Ldβ1) were cloned from L. decemlineata. These genes encode 822-, 753-, 672-, and 759-amino acid proteins, respectively, which share typical features of insect nAChRs subunits and closely resemble the corresponding subunits of the nAChRs from Tribolium castaneum. Temporal and spatial expression analyses showed that these genes, as well as the previously identified Ldα1, Ldα2, and Ldα8 genes, are widely expressed in all developmental stages, including eggs, larvae of various instars, pupae, and adults. All genes monitored were expressed at higher levels in the head than in the thorax and abdomen, except for Ldα10. Dietary ingestion of double-stranded RNA bacterially expressed for Ldα1 (dsLdα1) significantly reduced the mRNA level of Ldα1 in treated larvae and adults by 48.0% and 78.6%, respectively. Among the non-target genes, Ldα3, Ldα9, and Ldβ1 were significantly up-regulated in larvae. A toxicity bioassay showed that dsLdα1 treatment greatly decreased the sensitivity to imidacloprid and thiamethoxam in adults. The larval susceptibility to thiamethoxam but not to imidacloprid was also reduced because of the lower down-regulation of Ldα1. Thus, our results suggest that Ldα1 encodes a subunit of a functional nAChR that mediates the

  6. Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress.

    PubMed

    Zhang, Huan; Zhang, Qian; Zhai, Hong; Li, Yan; Wang, Xiangfeng; Liu, Qingchang; He, Shaozhen

    2017-01-13

    Sweet potato is an important food and bio-energy crop, and investigating the mechanisms underlying salt tolerance will provide information for salt-tolerant breeding of this crop. Here, the root transcriptomes of the salt-sensitive variety Lizixiang and the salt-tolerant line ND98 were compared to identify the genes and pathways involved in salt stress responses. In total, 8,744 and 10,413 differentially expressed genes (DEGs) in Lizixiang and ND98, respectively, were involved in salt responses. A lower DNA methylation level was detected in ND98 than in Lizixiang. In both genotypes, the DEGs, which function in phytohormone synthesis and signalling and ion homeostasis, may underlie the different degrees of salt tolerance. Significant up-regulations of the genes involved in the jasmonic acid (JA) biosynthesis and signalling pathways and ion transport, more accumulation of JA, a higher degree of stomatal closure and a lower level of Na(+) were found in ND98 compared to Lizixiang. This is the first report on transcriptome responses to salt tolerance in sweet potato. These results reveal that the JA signalling pathway plays important roles in the response of sweet potato to salt stress. This study provides insights into the mechanisms and genes involved in the salt tolerance of sweet potato.

  7. Transcript profile analysis reveals important roles of jasmonic acid signalling pathway in the response of sweet potato to salt stress

    PubMed Central

    Zhang, Huan; Zhang, Qian; Zhai, Hong; Li, Yan; Wang, Xiangfeng; Liu, Qingchang; He, Shaozhen

    2017-01-01

    Sweet potato is an important food and bio-energy crop, and investigating the mechanisms underlying salt tolerance will provide information for salt-tolerant breeding of this crop. Here, the root transcriptomes of the salt-sensitive variety Lizixiang and the salt-tolerant line ND98 were compared to identify the genes and pathways involved in salt stress responses. In total, 8,744 and 10,413 differentially expressed genes (DEGs) in Lizixiang and ND98, respectively, were involved in salt responses. A lower DNA methylation level was detected in ND98 than in Lizixiang. In both genotypes, the DEGs, which function in phytohormone synthesis and signalling and ion homeostasis, may underlie the different degrees of salt tolerance. Significant up-regulations of the genes involved in the jasmonic acid (JA) biosynthesis and signalling pathways and ion transport, more accumulation of JA, a higher degree of stomatal closure and a lower level of Na+ were found in ND98 compared to Lizixiang. This is the first report on transcriptome responses to salt tolerance in sweet potato. These results reveal that the JA signalling pathway plays important roles in the response of sweet potato to salt stress. This study provides insights into the mechanisms and genes involved in the salt tolerance of sweet potato. PMID:28084460

  8. Crystal Structure and Substrate Recognition of Cellobionic Acid Phosphorylase, Which Plays a Key Role in Oxidative Cellulose Degradation by Microbes.

    PubMed

    Nam, Young-Woo; Nihira, Takanori; Arakawa, Takatoshi; Saito, Yuka; Kitaoka, Motomitsu; Nakai, Hiroyuki; Fushinobu, Shinya

    2015-07-24

    The microbial oxidative cellulose degradation system is attracting significant research attention after the recent discovery of lytic polysaccharide mono-oxygenases. A primary product of the oxidative and hydrolytic cellulose degradation system is cellobionic acid (CbA), the aldonic acid form of cellobiose. We previously demonstrated that the intracellular enzyme belonging to glycoside hydrolase family 94 from cellulolytic fungus and bacterium is cellobionic acid phosphorylase (CBAP), which catalyzes reversible phosphorolysis of CbA into glucose 1-phosphate and gluconic acid (GlcA). In this report, we describe the biochemical characterization and the three-dimensional structure of CBAP from the marine cellulolytic bacterium Saccharophagus degradans. Structures of ligand-free and complex forms with CbA, GlcA, and a synthetic disaccharide product from glucuronic acid were determined at resolutions of up to 1.6 Å. The active site is located near the dimer interface. At subsite +1, the carboxylate group of GlcA and CbA is recognized by Arg-609 and Lys-613. Additionally, one residue from the neighboring protomer (Gln-190) is involved in the carboxylate recognition of GlcA. A mutational analysis indicated that these residues are critical for the binding and catalysis of the aldonic and uronic acid acceptors GlcA and glucuronic acid. Structural and sequence comparisons with other glycoside hydrolase family 94 phosphorylases revealed that CBAPs have a unique subsite +1 with a distinct amino acid residue conservation pattern at this site. This study provides molecular insight into the energetically efficient metabolic pathway of oxidized sugars that links the oxidative cellulolytic pathway to the glycolytic and pentose phosphate pathways in cellulolytic microbes.

  9. Crystal Structure and Substrate Recognition of Cellobionic Acid Phosphorylase, Which Plays a Key Role in Oxidative Cellulose Degradation by Microbes*

    PubMed Central

    Nam, Young-Woo; Nihira, Takanori; Arakawa, Takatoshi; Saito, Yuka; Kitaoka, Motomitsu; Nakai, Hiroyuki; Fushinobu, Shinya

    2015-01-01

    The microbial oxidative cellulose degradation system is attracting significant research attention after the recent discovery of lytic polysaccharide mono-oxygenases. A primary product of the oxidative and hydrolytic cellulose degradation system is cellobionic acid (CbA), the aldonic acid form of cellobiose. We previously demonstrated that the intracellular enzyme belonging to glycoside hydrolase family 94 from cellulolytic fungus and bacterium is cellobionic acid phosphorylase (CBAP), which catalyzes reversible phosphorolysis of CbA into glucose 1-phosphate and gluconic acid (GlcA). In this report, we describe the biochemical characterization and the three-dimensional structure of CBAP from the marine cellulolytic bacterium Saccharophagus degradans. Structures of ligand-free and complex forms with CbA, GlcA, and a synthetic disaccharide product from glucuronic acid were determined at resolutions of up to 1.6 Å. The active site is located near the dimer interface. At subsite +1, the carboxylate group of GlcA and CbA is recognized by Arg-609 and Lys-613. Additionally, one residue from the neighboring protomer (Gln-190) is involved in the carboxylate recognition of GlcA. A mutational analysis indicated that these residues are critical for the binding and catalysis of the aldonic and uronic acid acceptors GlcA and glucuronic acid. Structural and sequence comparisons with other glycoside hydrolase family 94 phosphorylases revealed that CBAPs have a unique subsite +1 with a distinct amino acid residue conservation pattern at this site. This study provides molecular insight into the energetically efficient metabolic pathway of oxidized sugars that links the oxidative cellulolytic pathway to the glycolytic and pentose phosphate pathways in cellulolytic microbes. PMID:26041776

  10. Reduced Triacylglycerol Mobilization during Seed Germination and Early Seedling Growth in Arabidopsis Containing Nutritionally Important Polyunsaturated Fatty Acids

    PubMed Central

    Shrestha, Pushkar; Callahan, Damien L.; Singh, Surinder P.; Petrie, James R.; Zhou, Xue-Rong

    2016-01-01

    There are now several examples of plant species engineered to synthesize and accumulate nutritionally important polyunsaturated fatty acids in their seed triacylglycerols (TAG). The utilization of TAG in germinating seeds of such transgenic plants was unknown. In this study, we examined the TAG utilization efficiency during seed germination in transgenic Arabidopsis seeds containing several examples of these fatty acids. Seed TAG species with native fatty acids had higher utilization rate than the TAG species containing transgenically produced polyunsaturated fatty acids. Conversely, quantification of the fatty acid components remaining in the total TAG after early stages of seed germination revealed that the undigested TAGs tended to contain elevated levels of the engineered polyunsaturated fatty acids (PUFA). LC-MS analysis further revealed asymmetrical mobilization rates for the individual TAG species. TAGs which contained multiple PUFA fatty acids were mobilized slower than the species containing single PUFA. The mobilized engineered fatty acids were used in de novo membrane lipid synthesis during seedling development. PMID:27725822

  11. Hydrophobic interactions and ionic networks play an important role in thermal stability and denaturation mechanism of the porcine odorant-binding protein.

    PubMed

    Stepanenko, Olesya V; Marabotti, Anna; Kuznetsova, Irina M; Turoverov, Konstantin K; Fini, Carlo; Varriale, Antonio; Staiano, Maria; Rossi, Mose'; D'Auria, Sabato

    2008-04-01

    Despite the fact that the porcine odorant-binding protein (pOBP) possesses a single tryptophan residue (Trp 16) that is characterized by a high density microenvironment (80 atoms in a sphere with radius 7 A) with only one polar group (Lys 120) and three bound water molecules, pOBP displayed a red shifted fluorescence emission spectrum (lambda(max) = 340 nm). The protein unfolding in 5M GdnHCl was accompanied by the red shift of the fluorescence emission spectrum (lambda(max) = 353 nm), by the increase of fluorescence quantum yield, and by the decrease of lifetime of the excited state (from 4.25 ns in native state to 3.15 ns in the presence of 5M GdnHCl). Taken together these data indicate the existence of an exciplex complex (Trp 16 with Lys 120 and/or with bound molecules of water) in the protein native state. Heat-induced denaturation of pOBP resulted in significant red shifts of the fluorescence emission spectra: the value of the ratio (I(320)/I(365)) upon excitation at lambda(ex) = 297 nm (parameter A) decreases from 1.07 to 0.64 passing from 60 to 85 degrees C, and the calculated midpoint of transition was centered at 70 degrees C. Interestingly, even at higher temperature, the values of the parameter A both in the absence and in the presence of GdnHCl did not coincide. This suggests that a portion of the protein structure is still preserved upon the temperature-induced denaturation of the protein in the absence of GdnHCl. CD experiments performed on pOBP in the absence and in the presence of GdnHCl and at different temperatures were in agreement with the fluorescence results. In addition, the obtained experimental data were corroborated by the analysis of the 3D structure of pOBP which revealed the amino acid residues that contribute to the protein dynamics and stability. Finally, molecular dynamics simulation experiments pointed out the important role of ion pair interactions as well as the molecular motifs that are responsible for the high thermal stability

  12. Metabolites derived from omega-3 polyunsaturated fatty acids are important for cardioprotection.

    PubMed

    Gilbert, Kim; Malick, Mandy; Madingou, Ness; Touchette, Charles; Bourque-Riel, Valérie; Tomaro, Leandro; Rousseau, Guy

    2015-12-15

    Although controversial, some data suggest that omega-3 polyunsaturated fatty acids (PUFA) are beneficial to cardiovascular diseases, and could reduce infarct size. In parallel, we have reported that the administration of Resolvin D1 (RvD1), a metabolite of docosahexaenoic acid, an omega-3 PUFA, can reduce infarct size. The present study was designed to determine if the inhibition of two important enzymes involved in the formation of RvD1 from omega-3 PUFA could reduce the cardioprotective effect of omega-3 PUFA. Sprague-Dawley rats were fed with a diet rich in omega-3 PUFA during 10 days before myocardial infarction (MI). Two days before MI, rats received a daily dose of Meloxicam, an inhibitor of cyclooxygenase-2, PD146176, an inhibitor of 15-lipoxygenase, both inhibitors or vehicle. MI was induced by the occlusion of the left coronary artery for 40min followed by reperfusion. Infarct size and neutrophil accumulation were evaluated after 24h of reperfusion while caspase-3, -8 and Akt activities were assessed at 30min of reperfusion. Rats receiving inhibitors, alone or in combination, showed a larger infarct size than those receiving omega-3 PUFA alone. Caspase-3 and -8 activities are higher in ischemic areas with inhibitors while Akt activity is diminished in groups treated with inhibitors. Moreover, the study showed that RvD1 restores cardioprotection when added to the inhibitors. Results from this study indicate that the inhibition of the metabolism of Omega-3 PUFA attenuate their cardioprotective properties. Then, resolvins seem to be an important mediator in the cardioprotection conferred by omega-3 PUFA in our experimental model of MI.

  13. Aspartic acid 413 is important for the normal allosteric functioning of ADP-glucose pyrophosphorylase.

    PubMed Central

    Greene, T W; Woodbury, R L; Okita, T W

    1996-01-01

    As part of a structure-function analysis of the higher-plant ADP-glucose pyrophosphorylase (AGP), we used a random mutagenesis approach in combination with a novel bacterial complementation system to isolate over 100 mutants that were defective in glycogen production (T.W. Greene, S.E. Chantler, M.L. Khan, G.F. Barry, J. Preiss, T.W. Okita [1996] Proc Natl Acad Sci USA 93: 1509-1513). One mutant of the large subunit M27 was identified by its capacity to only partially complement a mutation in the structural gene for the bacterial AGP (glg C), as determined by its light-staining phenotype when cells were exposed to l3 vapors. Enzyme-linked immunosorbent assay and enzymatic pyrophosphorylysis assays of M27 cell extracts showed that the level of expression and AGP activity was comparable to those of cells that expressed the wild-type recombinant enzyme. Kinetic analysis indicated that the M27 AGP displays normal Michaelis constant values for the substrates glucose-1-phosphate and ATP but requires 6- to 10-fold greater levels of 3-phosphoglycerate (3-PGA) than the wild-type recombinant enzyme for maximum activation. DNA sequence analysis showed that M27 contains a single point mutation that resulted in the replacement of aspartic acid 413 to alanine. Substitution of a lysine residue at this site almost completely abolished activation by 3-PGA. Aspartic acid 413 is adjacent to a lysine residue that was previously identified by chemical modification studies to be important in the binding of 3-PGA (K. Ball, J. Preiss [1994] J Biol Chem 269: 24706-24711). The kinetic properties of M27 corroborate the importance of this region in the allosteric regulation of a higher-plant AGP. PMID:8938421

  14. Amino acid residues 201-205 in C-terminal acidic tail region plays a crucial role in antibacterial activity of HMGB1

    PubMed Central

    2009-01-01

    Background Antibacterial activity is a novel function of high-mobility group box 1 (HMGB1). However, the functional site for this new effect is presently unknown. Methods and Results In this study, recombinant human HMGB1 A box and B box (rHMGB1 A box, rHMGB1 B box), recombinant human HMGB1 (rHMGB1) and the truncated C-terminal acidic tail mutant (tHMGB1) were prepared by the prokaryotic expression system. The C-terminal acidic tail (C peptide) was synthesized, which was composed of 30 amino acid residues. Antibacterial assays showed that both the full length rHMGB1 and the synthetic C peptide alone could efficiently inhibit bacteria proliferation, but rHMGB1 A box and B box, and tHMGB1 lacking the C-terminal acidic tail had no antibacterial function. These results suggest that C-terminal acidic tail is the key region for the antibacterial activity of HMGB1. Furthermore, we prepared eleven different deleted mutants lacking several amino acid residues in C-terminal acidic tail of HMGB1. Antibacterial assays of these mutants demonstrate that the amino acid residues 201-205 in C-terminal acidic tail region is the core functional site for the antibacterial activity of the molecule. Conclusion In sum, these results define the key region and the crucial site in HMGB1 for its antibacterial function, which is helpful to illustrating the antibacterial mechanisms of HMGB1. PMID:19751520

  15. RodZ and PgsA Play Intertwined Roles in Membrane Homeostasis of Bacillus subtilis and Resistance to Weak Organic Acid Stress

    PubMed Central

    van Beilen, Johan; Blohmke, Christoph J.; Folkerts, Hendrik; de Boer, Richard; Zakrzewska, Anna; Kulik, Wim; Vaz, Fred M.; Brul, Stanley; Ter Beek, Alexander

    2016-01-01

    Weak organic acids like sorbic and acetic acid are widely used to prevent growth of spoilage organisms such as Bacilli. To identify genes involved in weak acid stress tolerance we screened a transposon mutant library of Bacillus subtilis for sorbic acid sensitivity. Mutants of the rodZ (ymfM) gene were found to be hypersensitive to the lipophilic weak organic acid. RodZ is involved in determining the cell’s rod-shape and believed to interact with the bacterial actin-like MreB cytoskeleton. Since rodZ lies upstream in the genome of the essential gene pgsA (phosphatidylglycerol phosphate synthase) we hypothesized that expression of the latter might also be affected in rodZ mutants and hence contribute to the phenotype observed. We show that both genes are co-transcribed and that both the rodZ::mini-Tn10 mutant and a conditional pgsA mutant, under conditions of minimal pgsA expression, were sensitive to sorbic and acetic acid. Both strains displayed a severely altered membrane composition. Compared to the wild-type strain, phosphatidylglycerol and cardiolipin levels were lowered and the average acyl chain length was elongated. Induction of rodZ expression from a plasmid in our transposon mutant led to no recovery of weak acid susceptibility comparable to wild-type levels. However, pgsA overexpression in the same mutant partly restored sorbic acid susceptibility and fully restored acetic acid sensitivity. A construct containing both rodZ and pgsA as on the genome led to some restored growth as well. We propose that RodZ and PgsA play intertwined roles in membrane homeostasis and tolerance to weak organic acid stress. PMID:27818647

  16. Play Therapy

    PubMed Central

    Kool, Ritesh

    2010-01-01

    Play therapy represents a unique form of treatment that is not only geared toward young children, but is translated into a language children can comprehend and utilize—the language of play. For the referring provider or practitioner, questions may remain regarding the nature, course, and efficacy of play therapy. This article reviews the theoretical underpinnings of play therapy, some practical considerations, and finally a summary of the current state of research in regard to play therapy. The authors present the practicing psychiatrist with a road map for referring a patient to play therapy or initiating it in appropriate cases. PMID:21103141

  17. Enhancing Playful Teachers' Perception of the Importance of ICT Use in the Classroom: The Role of Risk Taking as a Mediator

    ERIC Educational Resources Information Center

    Goodwin, A. Lin; Low, Ee Ling; Ng, Pak Tee; Yeung, Alexander S.; Cai, Li

    2015-01-01

    In today's world, teaching and learning processes inevitably involve the application of information and communication technology (ICT). It seems reasonable to expect personal attributes such as cognitive playfulness to be associated with consistent application of ICT. Using survey responses from Singapore students in a teacher education programme…

  18. The behavior and importance of lactic acid complexation in Talspeak extraction systems

    SciTech Connect

    Grimes, Travis S.; Nilsson, Mikael; Nash, Kenneth L.

    2008-07-01

    Advanced partitioning of spent nuclear fuel in the UREX +la process relies on the TALSPEAK process for separation of fission-product lanthanides from trivalent actinides. The classic TALSPEAK utilizes an aqueous medium of both lactic acid and diethylenetriaminepentaacetic acid and the extraction reagent di(2-ethylhexyl)phosphoric acid in an aromatic diluent. In this study, the specific role of lactic acid and the complexes involved in the extraction of the trivalent actinides and lanthanides have been investigated using {sup 14}C-labeled lactic acid. Our results show that lactic acid partitions between the phases in a complex fashion. (authors)

  19. Structure-function studies of nerve growth factor: functional importance of highly conserved amino acid residues.

    PubMed Central

    Ibáñez, C F; Hallböök, F; Ebendal, T; Persson, H

    1990-01-01

    Selected amino acid residues in chicken nerve growth factor (NGF) were replaced by site-directed mutagenesis. Mutated NGF sequences were transiently expressed in COS cells and the yield of NGF protein in conditioned medium was quantified by Western blotting. Binding of each mutant to NGF receptors on PC12 cells was evaluated in a competition assay. The biological activity was determined by measuring stimulation of neurite outgrowth from chick sympathetic ganglia. The residues homologous to the proposed receptor binding site of insulin (Ser18, Met19, Val21, Asp23) were substituted by Ala. Replacement of Ser18, Met19 and Asp23 did not affect NGF activity. Modification of Val21 notably reduced both receptor binding and biological activity, suggesting that this residue is important to retain a fully active NGF. The highly conserved Tyr51 and Arg99 were converted into Phe and Lys respectively, without changing the biological properties of the molecule. However, binding and biological activity were greatly impaired after the simultaneous replacement of both Arg99 and Arg102 by Gly. The three conserved Trp residues at positions 20, 75 and 98 were substituted by Phe. The Trp mutated proteins retained 15-60% of receptor binding and 40-80% of biological activity, indicating that the Trp residues are not essential for NGF activity. However, replacement of Trp20 significantly reduced the amount of NGF in the medium, suggesting that this residue may be important for protein stability. Images Fig. 4. PMID:2328722

  20. The importance of the excitatory amino acid transporter 3 (EAAT3).

    PubMed

    Bjørn-Yoshimoto, Walden E; Underhill, Suzanne M

    2016-09-01

    The neuronal excitatory amino acid transporter 3 (EAAT3) is fairly ubiquitously expressed in the brain, though it does not necessarily maintain the same function everywhere. It is important in maintaining low local concentrations of glutamate, where its predominant post-synaptic localization can buffer nearby glutamate receptors and modulate excitatory neurotransmission and synaptic plasticity. It is also the main neuronal cysteine uptake system acting as the rate-limiting factor for the synthesis of glutathione, a potent antioxidant, in EAAT3 expressing neurons, while on GABAergic neurons, it is important in supplying glutamate as a precursor for GABA synthesis. Several diseases implicate EAAT3, and modulation of this transporter could prove a useful therapeutic approach. Regulation of EAAT3 could be targeted at several points for functional modulation, including the level of transcription, trafficking and direct pharmacological modulation, and indeed, compounds and experimental treatments have been identified that regulate EAAT3 function at different stages, which together with observations of EAAT3 regulation in patients is giving us insight into the endogenous function of this transporter, as well as the consequences of altered function. This review summarizes work done on elucidating the role and regulation of EAAT3.

  1. Fatty acid synthase plays a role in cancer metabolism beyond providing fatty acids for phospholipid synthesis or sustaining elevations in glycolytic activity

    SciTech Connect

    Hopperton, Kathryn E.; Duncan, Robin E.; Bazinet, Richard P.; Archer, Michael C.

    2014-01-15

    Fatty acid synthase is over-expressed in many cancers and its activity is required for cancer cell survival, but the role of endogenously synthesized fatty acids in cancer is unknown. It has been suggested that endogenous fatty acid synthesis is either needed to support the growth of rapidly dividing cells, or to maintain elevated glycolysis (the Warburg effect) that is characteristic of cancer cells. Here, we investigate both hypotheses. First, we compared utilization of fatty acids synthesized endogenously from {sup 14}C-labeled acetate to those supplied exogenously as {sup 14}C-labeled palmitate in the culture medium in human breast cancer (MCF-7 and MDA-MB-231) and untransformed breast epithelial cells (MCF-10A). We found that cancer cells do not produce fatty acids that are different from those derived from exogenous palmitate, that these fatty acids are esterified to the same lipid and phospholipid classes in the same proportions, and that their distribution within neutral lipids is not different from untransformed cells. These results suggest that endogenously synthesized fatty acids do not fulfill a specific function in cancer cells. Furthermore, we observed that cancer cells excrete endogenously synthesized fatty acids, suggesting that they are produced in excess of requirements. We next investigated whether lipogenic activity is involved in the maintenance of high glycolytic activity by culturing both cancer and non-transformed cells under anoxic conditions. Although anoxia increased glycolysis 2–3 fold, we observed no concomitant increase in lipogenesis. Our results indicate that breast cancer cells do not have a specific qualitative or quantitative requirement for endogenously synthesized fatty acids and that increased de novo lipogenesis is not required to sustain elevations in glycolytic activity induced by anoxia in these cells. - Highlights: • Fatty acid synthase (FASN) is over-expressed in cancer but its function is unknown. • We compare

  2. City Play.

    ERIC Educational Resources Information Center

    Dargan, Amanda; Zeitlin, Steve

    2000-01-01

    Today, fewer city blocks preserve the confidence of lifestyle and urban geography that sustain traditional games and outdoor play. Large groups of children choosing sides and organizing Red Rover games are no longer commonplace. Teachers must encourage free play; urban planners must build cities that are safe play havens. (MLH)

  3. Global formic acid measurements from space: The importance of biomass burning emissions

    NASA Astrophysics Data System (ADS)

    Chaliyakunnel, S.; Millet, D. B.; Wells, K. C.; Cady-Pereira, K. E.; Shephard, M. W.

    2013-12-01

    Formic acid is one of the most abundant carboxylic acids in the atmosphere, and a dominant source of acidity in the global troposphere. In this work, we present the first global retrievals of formic acid from the Tropospheric Emission Spectrometer (TES) satellite instrument. We apply the GEOS-Chem Chemical Transport Model (CTM) and an ensemble of airborne and ground observations to evaluate the TES data, and find that the formic acid distributions derived from TES are consistent with in situ measurements. The space-based formic acid data reveal a severe model underestimate that manifests globally; however, the simulated and observed concentrations are spatially well-correlated. The discrepancy between GEOS-Chem and TES is most prominent over tropical biomass burning regions, indicating a major missing source of organic acids from fires. We use the TES data to derive new top-down constraints on the pyrogenic source of formic acid to the atmosphere.

  4. Social-communicative abilities as treatment goals for preschool children with autism spectrum disorder: the importance of imitation, joint attention, and play.

    PubMed

    Warreyn, Petra; van der Paelt, Sara; Roeyers, Herbert

    2014-08-01

    Autism spectrum disorder (ASD) is a pervasive developmental disorder with a lifelong impact on multiple domains of functioning. Often, a diagnosis is possible by 3 years of age. Given the benefits of early intervention, it is advisable to start treatment as soon as possible after the diagnosis has been made. Among other factors, early intervention should focus on social-communicative abilities such as imitation, joint attention, and play. In this review, the typical developmental course and functions of these social-communicative abilities are described, and the problems young children with ASD experience in this domain. In addition, different approaches to promoting these abilities are explained. The authors recommend the inclusion of imitation, joint attention, and play as treatment goals in community settings for children with ASD.

  5. Fatty acid synthase plays a role in cancer metabolism beyond providing fatty acids for phospholipid synthesis or sustaining elevations in glycolytic activity.

    PubMed

    Hopperton, Kathryn E; Duncan, Robin E; Bazinet, Richard P; Archer, Michael C

    2014-01-15

    Fatty acid synthase is over-expressed in many cancers and its activity is required for cancer cell survival, but the role of endogenously synthesized fatty acids in cancer is unknown. It has been suggested that endogenous fatty acid synthesis is either needed to support the growth of rapidly dividing cells, or to maintain elevated glycolysis (the Warburg effect) that is characteristic of cancer cells. Here, we investigate both hypotheses. First, we compared utilization of fatty acids synthesized endogenously from (14)C-labeled acetate to those supplied exogenously as (14)C-labeled palmitate in the culture medium in human breast cancer (MCF-7 and MDA-MB-231) and untransformed breast epithelial cells (MCF-10A). We found that cancer cells do not produce fatty acids that are different from those derived from exogenous palmitate, that these fatty acids are esterified to the same lipid and phospholipid classes in the same proportions, and that their distribution within neutral lipids is not different from untransformed cells. These results suggest that endogenously synthesized fatty acids do not fulfill a specific function in cancer cells. Furthermore, we observed that cancer cells excrete endogenously synthesized fatty acids, suggesting that they are produced in excess of requirements. We next investigated whether lipogenic activity is involved in the maintenance of high glycolytic activity by culturing both cancer and non-transformed cells under anoxic conditions. Although anoxia increased glycolysis 2-3 fold, we observed no concomitant increase in lipogenesis. Our results indicate that breast cancer cells do not have a specific qualitative or quantitative requirement for endogenously synthesized fatty acids and that increased de novo lipogenesis is not required to sustain elevations in glycolytic activity induced by anoxia in these cells.

  6. The source of inoculum plays a defining role in the development of MEC microbial consortia fed with acetic and propionic acid mixtures.

    PubMed

    Ruiz, Vianey; Ilhan, Zehra Esra; Kang, Dae-Wook; Krajmalnik-Brown, Rosa; Buitrón, Germán

    2014-07-20

    Microbial electrolysis cells (MECs) can be used as a downstream process to dark fermentation to further capture electron in volatile fatty acids that remain after fermentation, improving this way the viability of the overall process. Acetic and propionic acid are common products of dark fermentation. The main objective of this work was to investigate the effect of different initial concentrations of a mixture of acetic and propionic acids on MECs microbial ecology and hydrogen production performance. To link microbial structure and function, we characterized the anode respiring biofilm communities using pyrosequencing and quantitative-PCR. The best hydrogen production rates (265mL/d/Lreactor) were obtained in the first block of experiments by MEC fed with 1500mg/L acetic acid and 250mg/L propionic acid. This reactor presents in the anode biofilm an even distribution of Proteobacteria, Firmicutes and Bacteroidetes and Arcobacter was the dominant genera. The above fact also correlated to the highest electron load among all the reactors. It was evidenced that although defined acetic and propionic acid concentrations fed affected the structure of the microbial consortia that developed at the anode, the initial inoculum played a major role in the development of MEC microbial consortia.

  7. Play Therapy

    PubMed Central

    Lawver, Timothy; Blankenship, Kelly

    2008-01-01

    Play therapy is a treatment modality in which the therapist engages in play with the child. Its use has been documented in a variety of settings and with a variety of diagnoses. Treating within the context of play brings the therapist and the therapy to the level of the child. By way of an introduction to this approach, a case is presented of a six-year-old boy with oppositional defiant disorder. The presentation focuses on the events and interactions of a typical session with an established patient. The primary issues of the session are aggression, self worth, and self efficacy. These themes manifest themselves through the content of the child’s play and narration of his actions. The therapist then reflects these back to the child while gently encouraging the child toward more positive play. Though the example is one of nondirective play therapy, a wide range of variation exists under the heading of play therapy. PMID:19724720

  8. Phase diagrams and water activities of aqueous dicarboxylic acid systems of atmospheric importance.

    PubMed

    Beyer, Keith D; Friesen, Katherine; Bothe, Jameson R; Palet, Benjamin

    2008-11-20

    We have studied liquid/solid phase diagrams and water activities of the dicarboxylic acid/water binary systems for maleic, dl-malic, glutaric, and succinc acids using differential scanning calorimetry, infrared (IR) spectroscopy of thin films, and conductivity analysis of saturated solutions. For each binary system we report the measurements of the ice melting envelope, the acid dissolution envelope, and the ice/acid eutectic temperature and composition. Water activities have been determined by using the freezing point depression of ice. Additionally, an irreversible solid/solid phase transition for maleic acid was observed in both DSC and IR studies likely due to the conversion of a meta-stable crystal form of maleic acid to its most stable crystal form. In general we find good agreement with literature values for temperature-dependent acid solubilities.

  9. Two glycerol 3-phosphate dehydrogenase isogenes from Candida versatilis SN-18 play an important role in glycerol biosynthesis under osmotic stress.

    PubMed

    Mizushima, Daiki; Iwata, Hisashi; Ishimaki, Yuki; Ogihara, Jun; Kato, Jun; Kasumi, Takafumi

    2016-05-01

    Two isogenes of glycerol 3-phosphate dehydrogenase (GPD) from Candida versatilis SN-18 were cloned and sequenced. These intronless genes (Cagpd1 and Cagpd2) were both predicted to encode a 378 amino acid polypeptide, and the deduced amino acid sequences mutually showed 76% identity. Interestingly, Cagpd1 and Cagpd2 were located tandemly in a locus of genomic DNA within a 262 bp interval. To our knowledge, this represents a novel instance of isogenic genes relating to glucose metabolism. The stress response element (STRE) was found respectively at -93 to -89 bp upstream of the 5'end of Cagpd1 and -707 to -703 bp upstream of Cagpd2, indicating that these genes are involved in osmotic stress response. In heterologous expression using a gpd1Δgpd2Δ double deletion mutant of Saccharomyces cerevisiae, Cagpd1 and Cagpd2 transformants complemented the function of GPD, with Cagpd2 being much more effective than Cagpd1 in promoting growth and glycerol synthesis. Phylogenetic analysis of the amino acid sequences suggested that Cagpd1p and Cagpd2p are NADP(+)-dependent GPDs (EC 1.1.1.94). However, crude enzyme extract from Cagpd1 and Cagpd2 transformants showed GPD activity with only NAD(+) as cofactor. Hence, both Cagpd1p and Cagpd2p are likely NAD(+)-dependent GPDs (EC 1.1.1.8), similar to GPDs from S. cerevisiae and Candida magnoliae.

  10. Play Sheets. Let's Play! Project.

    ERIC Educational Resources Information Center

    State Univ. of New York, Buffalo. Center for Assistive Technology.

    This collection of play sheets for parents and early intervention personnel was developed by the "Let's Play! Project," a 3-year federally supported project that worked to promote play in infants and toddlers with disabilities through the use of "low-tech" assistive technology. Each single page guide provides guidance to…

  11. Importance of ALDH1A enzymes in determining human testicular retinoic acid concentrations

    PubMed Central

    Arnold, Samuel L.; Kent, Travis; Hogarth, Cathryn A.; Schlatt, Stefan; Prasad, Bhagwat; Haenisch, Michael; Walsh, Thomas; Muller, Charles H.; Griswold, Michael D.; Amory, John K.; Isoherranen, Nina

    2015-01-01

    Retinoic acid (RA), the active metabolite of vitamin A, is required for spermatogenesis and many other biological processes. RA formation requires irreversible oxidation of retinal to RA by aldehyde dehydrogenase enzymes of the 1A family (ALDH1A). While ALDH1A1, ALDH1A2, and ALDH1A3 all form RA, the expression pattern and relative contribution of these enzymes to RA formation in the testis is unknown. In this study, novel methods to measure ALDH1A protein levels and intrinsic RA formation were used to accurately predict RA formation velocities in individual human testis samples and an association between RA formation and intratesticular RA concentrations was observed. The distinct localization of ALDH1A in the testis suggests a specific role for each enzyme in controlling RA formation. ALDH1A1 was found in Sertoli cells, while only ALDH1A2 was found in spermatogonia, spermatids, and spermatocytes. In the absence of cellular retinol binding protein (CRBP)1, ALDH1A1 was predicted to be the main contributor to intratesticular RA formation, but when CRBP1 was present, ALDH1A2 was predicted to be equally important in RA formation as ALDH1A1. This study provides a comprehensive novel methodology to evaluate RA homeostasis in human tissues and provides insight to how the individual ALDH1A enzymes mediate RA concentrations in specific cell types. PMID:25502770

  12. Identification of important abiotic and biotic factors in the biodegradation of poly(l-lactic acid).

    PubMed

    Husárová, Lucie; Pekařová, Silvie; Stloukal, Petr; Kucharzcyk, Pavel; Verney, Vincent; Commereuc, Sophie; Ramone, Audrey; Koutny, Marek

    2014-11-01

    The biodegradation of four poly(l-lactic acid) (PLA) samples with molecular weights (MW) ranging from approximately 34 to 160kgmol(-1) was investigated under composting conditions. The biodegradation rate decreased, and initial retardation was discernible in parallel with the increasing MW of the polymer. Furthermore, the specific surface area of the polymer sample was identified as the important factor accelerating biodegradation. Microbial community compositions and dynamics during the biodegradation of different PLA were monitored by temperature gradient gel electrophoresis, and were found to be virtually identical for all PLA materials and independent of MW. A specific PLA degrading bacteria was isolated and tentatively designated Thermopolyspora flexuosa FTPLA. The addition of a limited amount of low MW PLA did not accelerate the biodegradation of high MW PLA, suggesting that the process is not limited to the number of specific degraders and/or the induction of specific enzymes. In parallel, abiotic hydrolysis was investigated for the same set of samples and their courses found to be quasi-identical with the biodegradation of all four PLA samples investigated. This suggests that the abiotic hydrolysis represented a rate limiting step in the biodegradation process and the organisms present were not able to accelerate depolymerization significantly by the action of their enzymes.

  13. Prionic Acid: An Effective Sex Attractant for an Important Pest of Sugarcane, Dorysthenes granulosus (Coleoptera: Cerambycidae: Prioninae).

    PubMed

    Wickham, Jacob D; Lu, Wen; Jin, Tao; Peng, Zhengqiang; Guo, Dongfeng; Millar, Jocelyn G; Hanks, Lawrence M; Chen, Yi

    2016-02-01

    Male Dorysthenes granulosus (Thomson, 1860) (Coleoptera: Cerambycidae: Prioninae) were caught in traps baited with racemic 3,5-dimethyldodecanoic acid (prionic acid) during field screening trials in China that tested known cerambycid pheromones. This species is an important pest of sugarcane (Saccharum officinarum L.). In follow-up dose-response trials, plastic sachets loaded with 1 or 0.1 mg of prionic acid were equally attractive to male beetles, whereas lower doses were no better than controls. Two commercial prionic acid lures also were attractive, suggesting that traps baited with prionic acid can be rapidly incorporated into integrated pest management programs targeting this major pest. It is likely that this compound is a major component of the female-produced sex pheromone of D. granulosus because this species is in the same subfamily as Prionus californicus Motschulsky, 1845, the species from which prionic acid was originally identified.

  14. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities

    PubMed Central

    FitzGerald, Jamie A.; Allen, Eoin; Wall, David M.; Jackson, Stephen A.; Murphy, Jerry D.; Dobson, Alan D. W.

    2015-01-01

    Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1) and strongest (R6) performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA) showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation. PMID:26555136

  15. β-Ketoacyl-acyl Carrier Protein Synthase I (KASI) Plays Crucial Roles in the Plant Growth and Fatty Acids Synthesis in Tobacco

    PubMed Central

    Yang, Tianquan; Xu, Ronghua; Chen, Jianghua; Liu, Aizhong

    2016-01-01

    Fatty acids serve many functions in plants, but the effects of some key genes involved in fatty acids biosynthesis on plants growth and development are not well understood yet. To understand the functions of 3-ketoacyl-acyl-carrier protein synthase I (KASI) in tobacco, we isolated two KASI homologs, which we have designated NtKASI-1 and NtKASI-2. Expression analysis showed that these two KASI genes were transcribed constitutively in all tissues examined. Over-expression of NtKASI-1 in tobacco changed the fatty acid content in leaves, whereas over-expressed lines of NtKASI-2 exhibited distinct phenotypic features such as slightly variegated leaves and reduction of the fatty acid content in leaves, similar to the silencing plants of NtKASI-1 gene. Interestingly, the silencing of NtKASI-2 gene had no discernibly altered phenotypes compared to wild type. The double silencing plants of these two genes enhanced the phenotypic changes during vegetative and reproductive growth compared to wild type. These results uncovered that these two KASI genes had the partially functional redundancy, and that the KASI genes played a key role in regulating fatty acids synthesis and in mediating plant growth and development in tobacco. PMID:27509494

  16. Looking into Children's Play Communities

    ERIC Educational Resources Information Center

    Mabry, Mark; Fucigna, Carolee

    2009-01-01

    Play, particularly children's sociodramatic play, is the cornerstone of early childhood classrooms in the United States. Early childhood educators learn and expound mantras of "the value of play," "play-based programs," "children learning through play," and "play as child's work." They strive to promote the importance of making a place for play in…

  17. Deep cerebellar nuclei play an important role in two-tone discrimination on delay eyeblink conditioning in C57BL/6 mice.

    PubMed

    Sakamoto, Toshiro; Endo, Shogo

    2013-01-01

    Previous studies have shown that deep cerebellar nuclei (DCN)-lesioned mice develop conditioned responses (CR) on delay eyeblink conditioning when a salient tone conditioned stimulus (CS) is used, which suggests that the cerebellum potentially plays a role in more complicated cognitive functions. In the present study, we examined the role of DCN in tone frequency discrimination in the delay eyeblink-conditioning paradigm. In the first experiment, DCN-lesioned and sham-operated mice were subjected to standard simple eyeblink conditioning under low-frequency tone CS (LCS: 1 kHz, 80 dB) or high-frequency tone CS (HCS: 10 kHz, 70 dB) conditions. DCN-lesioned mice developed CR in both CS conditions as well as sham-operated mice. In the second experiment, DCN-lesioned and sham-operated mice were subjected to two-tone discrimination tasks, with LCS+ (or HCS+) paired with unconditioned stimulus (US), and HCS- (or LCS-) without US. CR% in sham-operated mice increased in LCS+ (or HCS+) trials, regardless of tone frequency of CS, but not in HCS- (or LCS-) trials. The results indicate that sham-operated mice can discriminate between LCS+ and HCS- (or HCS+ and LCS-). In contrast, DCN-lesioned mice showed high CR% in not only LCS+ (or HCS+) trials but also HCS- (or LCS-) trials. The results indicate that DCN lesions impair the discrimination between tone frequency in eyeblink conditioning. Our results suggest that the cerebellum plays a pivotal role in the discrimination of tone frequency.

  18. The Polo-like kinase PLKA in Aspergillus nidulans is not essential but plays important roles during vegetative growth and development.

    PubMed

    Mogilevsky, Klarita; Glory, Amandeep; Bachewich, Catherine

    2012-02-01

    The Polo-like kinases (Plks) are conserved, multifunctional cell cycle regulators that are induced in many forms of cancer and play additional roles in metazoan development. We previously identified plkA in Aspergillus nidulans, the only Plk investigated in filamentous fungi to date, and partially characterized its function through overexpression. Here, we report the plkA null phenotype. Surprisingly, plkA was not essential, unlike Plks in other organisms that contain a single homologue. A subset of cells lacking PLKA contained defects in spindle formation and chromosome organization, supporting some conservation in cell cycle function. However, septa were present, suggesting that PLKA, unlike other Plks, is not a central regulator of septation. Colonies lacking PLKA were compact with multibranched hyphae, implying a role for this factor in aspects of hyphal morphogenesis. These defects were suppressed by high temperature or low concentrations of benomyl, suggesting that PLKA may function during vegetative growth by influencing microtubule dynamics. However, the colonies also showed reduced conidiation and precocious formation of sexual Hülle cells in a benomyl- and temperature-insensitive manner. This result suggests that PLKA may influence reproduction through distinct mechanisms and represents the first example of a link between Plk function and development in fungi. Finally, filamentous fungal Plks have distinct features, and phylogenetic analyses reveal that they may group more closely with metazoan PLK4. In contrast, yeast Plks are more similar to metazoan proteins PLK1 to PLK3. Thus, A. nidulans PLKA shows some conservation in cell cycle function but may also play novel roles during hyphal morphogenesis and development.

  19. Why Play?

    ERIC Educational Resources Information Center

    Weininger, O.

    This paper draws together briefly theories and knowledge from research in morphology and cognitive psychology, as well as some hypothetical information from traditional psychiatry, to show the ramifications of play in children's development. Play is defined as any of a wide variety of behaviors through which an individual attempts to discover what…

  20. Playful Gaming.

    ERIC Educational Resources Information Center

    Makedon, Alex

    1984-01-01

    Discusses the concept of playful gaming (an idea not expressed fully by either term alone) and uses it as an analytical tool to study the playfulness of games in the context of several social phenomena; i.e., social change, socialization, utopian systems, and educational gaming. An extensive reference list is provided. (MBR)

  1. Playing Shakespeare.

    ERIC Educational Resources Information Center

    Bashian, Kathleen Ryniker

    1993-01-01

    Describes a yearlong project at 12 Catholic middle schools in the Diocese of Arlington, Virginia, to incorporate the plays of William Shakespeare into the curriculum. Teachers attended university lectures and directed students in performances of the plays. Concludes that Shakespeare can be understood and enjoyed by middle school students. (BCY)

  2. Shadow Play

    ERIC Educational Resources Information Center

    Trundle, Kathy Cabe; Hilson, Margilee P.

    2012-01-01

    A bunny rabbit playfully hops across the wall. Then hands realign and fingers shift to make a hawk soar toward the ceiling. Most children have enjoyed the delightful experience of playing with shadow puppets. The authors build on this natural curiosity to help students link shadows to complex astronomical concepts such as seasons. The…

  3. Prediction of enzyme function based on 3D templates of evolutionarily important amino acids

    PubMed Central

    Kristensen, David M; Ward, R Matthew; Lisewski, Andreas Martin; Erdin, Serkan; Chen, Brian Y; Fofanov, Viacheslav Y; Kimmel, Marek; Kavraki, Lydia E; Lichtarge, Olivier

    2008-01-01

    Background Structural genomics projects such as the Protein Structure Initiative (PSI) yield many new structures, but often these have no known molecular functions. One approach to recover this information is to use 3D templates – structure-function motifs that consist of a few functionally critical amino acids and may suggest functional similarity when geometrically matched to other structures. Since experimentally determined functional sites are not common enough to define 3D templates on a large scale, this work tests a computational strategy to select relevant residues for 3D templates. Results Based on evolutionary information and heuristics, an Evolutionary Trace Annotation (ETA) pipeline built templates for 98 enzymes, half taken from the PSI, and sought matches in a non-redundant structure database. On average each template matched 2.7 distinct proteins, of which 2.0 share the first three Enzyme Commission digits as the template's enzyme of origin. In many cases (61%) a single most likely function could be predicted as the annotation with the most matches, and in these cases such a plurality vote identified the correct function with 87% accuracy. ETA was also found to be complementary to sequence homology-based annotations. When matches are required to both geometrically match the 3D template and to be sequence homologs found by BLAST or PSI-BLAST, the annotation accuracy is greater than either method alone, especially in the region of lower sequence identity where homology-based annotations are least reliable. Conclusion These data suggest that knowledge of evolutionarily important residues improves functional annotation among distant enzyme homologs. Since, unlike other 3D template approaches, the ETA method bypasses the need for experimental knowledge of the catalytic mechanism, it should prove a useful, large scale, and general adjunct to combine with other methods to decipher protein function in the structural proteome. PMID:18190718

  4. Glycolysis plays an important role in energy transfer from the base to the distal end of the flagellum in mouse sperm.

    PubMed

    Takei, Gen L; Miyashiro, Daisuke; Mukai, Chinatsu; Okuno, Makoto

    2014-06-01

    Many studies have been conducted to elucidate the relationship between energy metabolic pathways (glycolysis and respiration) and flagellar motility in mammalian sperm, but the contribution of glycolysis to sperm motility has not yet been fully elucidated. In the present study, we performed detailed analysis of mouse sperm flagellar motility for further understanding of the contribution of glycolysis to mammalian sperm motility. Mouse sperm maintained vigorous motility in the presence of substrates either for glycolysis or for respiration. By contrast, inhibition of glycolysis by alpha-chlorohydrine caused a significant decrease in the bend angle of the flagellar bending wave, sliding velocity of outer doublet microtubules and ATP content even in the presence of respiratory substrates (pyruvate or β-hydroxybutyrate). The decrease of flagellar bend angle and sliding velocity are prominent in the distal part of the flagellum, indicating that glycolysis inhibition caused the decrease in ATP concentration threrein. These results suggest that glycolysis potentially acts as a spatial ATP buffering system, transferring energy (ATP) synthesized by respiration at the mitochondria located in the basal part of the flagellum to the distal part. In order to validate that glycolytic enzymes can transfer high energy phosphoryls, we calculated intraflagellar concentration profiles of adenine nucleotides along the flagellum by computer simulation analysis. The result demonstrated the involvement of glycolysis for maintaining the ATP concentration at the tip of the flagellum. It is likely that glycolysis plays a key role in energy homeostasis in mouse sperm not only through ATP production but also through energy transfer.

  5. Five glutamic acid residues in the C-terminal domain of the ChlD subunit play a major role in conferring Mg(2+) cooperativity upon magnesium chelatase.

    PubMed

    Brindley, Amanda A; Adams, Nathan B P; Hunter, C Neil; Reid, James D

    2015-11-10

    Magnesium chelatase catalyzes the first committed step in chlorophyll biosynthesis by inserting a Mg(2+) ion into protoporphyrin IX in an ATP-dependent manner. The cyanobacterial (Synechocystis) and higher-plant chelatases exhibit a complex cooperative response to free magnesium, while the chelatases from Thermosynechococcus elongatus and photosynthetic bacteria do not. To investigate the basis for this cooperativity, we constructed a series of chimeric ChlD proteins using N-terminal, central, and C-terminal domains from Synechocystis and Thermosynechococcus. We show that five glutamic acid residues in the C-terminal domain play a major role in this process.

  6. Salicylic acid binding of mitochondrial alpha-ketoglutarate dehydrogenase E2 affects mitochondrial oxidative phosphorylation and electron transport chain components and plays a role in basal defense against tobacco mosaic virus in tomato.

    PubMed

    Liao, Yangwenke; Tian, Miaoying; Zhang, Huan; Li, Xin; Wang, Yu; Xia, Xiaojian; Zhou, Jie; Zhou, Yanhong; Yu, Jingquan; Shi, Kai; Klessig, Daniel F

    2015-02-01

    Salicylic acid (SA) plays a critical role in plant defense against pathogen invasion. SA-induced viral defense in plants is distinct from the pathways mediating bacterial and fungal defense and involves a specific pathway mediated by mitochondria; however, the underlying mechanisms remain largely unknown. The SA-binding activity of the recombinant tomato (Solanum lycopersicum) alpha-ketoglutarate dehydrogenase (Slα-kGDH) E2 subunit of the tricarboxylic acid (TCA) cycle was characterized. The biological role of this binding in plant defenses against tobacco mosaic virus (TMV) was further investigated via Slα-kGDH E2 silencing and transient overexpression in plants. Slα-kGDH E2 was found to bind SA in two independent assays. SA treatment, as well as Slα-kGDH E2 silencing, increased resistance to TMV. SA did not further enhance TMV defense in Slα-kGDH E2-silenced tomato plants but did reduce TMV susceptibility in Nicotiana benthamiana plants transiently overexpressing Slα-kGDH E2. Furthermore, Slα-kGDH E2-silencing-induced TMV resistance was fully blocked by bongkrekic acid application and alternative oxidase 1a silencing. These results indicated that binding by Slα-kGDH E2 of SA acts upstream of and affects the mitochondrial electron transport chain, which plays an important role in basal defense against TMV. The findings of this study help to elucidate the mechanisms of SA-induced viral defense.

  7. Lysophosphatidic Acid Receptor Type 1 (LPA1) Plays a Functional Role in Osteoclast Differentiation and Bone Resorption Activity*

    PubMed Central

    David, Marion; Machuca-Gayet, Irma; Kikuta, Junichi; Ottewell, Penelope; Mima, Fuka; Leblanc, Raphael; Bonnelye, Edith; Ribeiro, Johnny; Holen, Ingunn; Vales, Rùben Lopez; Jurdic, Pierre; Chun, Jerold; Clézardin, Philippe; Ishii, Masaru; Peyruchaud, Olivier

    2014-01-01

    Lysophosphatidic acid (LPA) is a natural bioactive lipid that acts through six different G protein-coupled receptors (LPA1–6) with pleiotropic activities on multiple cell types. We have previously demonstrated that LPA is necessary for successful in vitro osteoclastogenesis of bone marrow cells. Bone cells controlling bone remodeling (i.e. osteoblasts, osteoclasts, and osteocytes) express LPA1, but delineating the role of this receptor in bone remodeling is still pending. Despite Lpar1−/− mice displaying a low bone mass phenotype, we demonstrated that bone marrow cell-induced osteoclastogenesis was reduced in Lpar1−/− mice but not in Lpar2−/− and Lpar3−/− animals. Expression of LPA1 was up-regulated during osteoclastogenesis, and LPA1 antagonists (Ki16425, Debio0719, and VPC12249) inhibited osteoclast differentiation. Blocking LPA1 activity with Ki16425 inhibited expression of nuclear factor of activated T-cell cytoplasmic 1 (NFATc1) and dendritic cell-specific transmembrane protein and interfered with the fusion but not the proliferation of osteoclast precursors. Similar to wild type osteoclasts treated with Ki16425, mature Lpar1−/− osteoclasts had reduced podosome belt and sealing zone resulting in reduced mineralized matrix resorption. Additionally, LPA1 expression markedly increased in the bone of ovariectomized mice, which was blocked by bisphosphonate treatment. Conversely, systemic treatment with Debio0719 prevented ovariectomy-induced cancellous bone loss. Moreover, intravital multiphoton microscopy revealed that Debio0719 reduced the retention of CX3CR1-EGFP+ osteoclast precursors in bone by increasing their mobility in the bone marrow cavity. Overall, our results demonstrate that LPA1 is essential for in vitro and in vivo osteoclast activities. Therefore, LPA1 emerges as a new target for the treatment of diseases associated with excess bone loss. PMID:24429286

  8. Campylobacter jejuni serine protease HtrA plays an important role in heat tolerance, oxygen resistance, host cell adhesion, invasion, and transmigration

    PubMed Central

    Lind, Judith; Backert, Steffen; Tegtmeyer, Nicole

    2015-01-01

    Campylobacter jejuni is an important pathogen of foodborne illness. Transmigration across the intestinal epithelial barrier and invasion are considered as primary reasons for tissue damage triggered by C. jejuni. Using knockout mutants, it was shown that the serine protease HtrA may be important for stress tolerance and physiology of C. jejuni. HtrA is also secreted in the extra­cellular environment, where it can cleave junctional host cell proteins such as E-cadherin. Aim of the present study was to establish a genetic complementation system in two C. jejuni strains in order to introduce the wild-type htrA gene in trans, test known htrA phenotypes, and provide the basis to perform further mutagenesis. We confirm that reexpression of the htrA wild-type gene in ΔhtrA mutants restored the following phenotypes: 1) C. jejuni growth at high temperature (44 °C), 2) growth under high oxygen stress conditions, 3) expression of proteolytically active HtrA oligomers, 4) secretion of HtrA into the supernatant, 5) cell attachment and invasion, and 6) transmigration across polarized epithelial cells. These results establish a genetic complementation system for htrA in C. jejuni, exclude polar effects in the ΔhtrA mutants, confirm important HtrA properties, and permit the discovery and dissection of new functions. PMID:25883795

  9. Play Is the Way

    ERIC Educational Resources Information Center

    Gross, Steve; Sanderson, Rebecca Cornelli

    2012-01-01

    Historically, play has been viewed as a frivolous break from important endeavors like working and learning when, in fact, a child's ability to fully and freely engage in play is essential to their learning, productivity, and overall development. A natural drive to play is universal across all young mammals. Children from every society on earth…

  10. The Pedagogy of Play

    ERIC Educational Resources Information Center

    Giesbrecht, Sheila

    2012-01-01

    Play is important. Environmental educators Sobel and Louv write about the relationship between children and outside play and suggest that early transcendental experiences within nature allow children to develop empathetic orientations towards the natural world. Children who play out-of-doors develop an appreciation for the environment and…

  11. Two people playing together: some thoughts on play, playing, and playfulness in psychoanalytic work.

    PubMed

    Vliegen, Nicole

    2009-01-01

    Children's play and the playfulness of adolescents and adults are important indicators of personal growth and development. When a child is not able to play, or an adolescent/adult is not able to be playful with thoughts and ideas, psychotherapy can help to find a more playful and creative stance. Elaborating Winnicott's (1968, p. 591) statement that "psychotherapy has to do with two people playing together," three perspectives on play in psychotherapy are discussed. In the first point of view, the child gets in touch with and can work through aspects of his or her inner world, while playing in the presence of the therapist. The power of play is then rooted in the playful communication with the self In a second perspective, in play the child is communicating aspects of his or her inner world to the therapist as a significant other. In a third view, in "playing together" child and therapist are coconstructing new meanings. These three perspectives on play are valid at different moments of a therapy process or for different children, depending on the complex vicissitudes of the child's constitution, life experiences, development, and psychic structure. Concerning these three perspectives, a parallel can be drawn between the therapist's attitude toward the child's play and the way the therapist responds to the verbal play of an adolescent or adult. We illustrate this with the case of Jacob, a late adolescent hardly able to play with ideas.

  12. Upregulation of PDZK1 by Calculus Bovis Sativus May Play an Important Role in Restoring Biliary Transport Function in Intrahepatic Cholestasis

    PubMed Central

    Xiang, Dong; Feng, Cheng-Yang; Li, Xi-Ping; Xu, Yan-Jiao; He, Wen-Xi; Lei, Kai; Cai, Hong-Jiao

    2017-01-01

    Intrahepatic cholestasis is a main cause of hepatic accumulation of bile acids leading to liver injury, fibrosis, and liver failure. Our previous studies proved that Calculus Bovis Sativus (CBS) can restore biliary transport function through upregulating the multidrug resistance-associated protein 2 (MRP2) and breast cancer resistance protein (BCRP) in 17α-ethynylestradiol- (EE-) induced intrahepatic cholestasis rats. The regulation mechanism of CBS on these transporters, however, remains unclear. This study was designed to evaluate the possible relationship between the effect of CBS on transport activities and the regulation of CBS on the expression of PDZK1, a mainly scaffold protein which can regulate MRP2 and BCRP. Intrahepatic cholestasis model was induced in rats with injection of EE for five consecutive days and then the biliary excretion rates and cumulative biliary excretions were measured. The mRNA and protein expression levels of PDZK1 were detected by reverse transcription-quantitative real-time polymerase chain reaction, western blot, and immunohistochemical analysis. When treated with CBS, cumulative biliary excretions and mRNA and protein expressions of PDZK1 were significantly increased in intrahepatic cholestasis rats. This study demonstrated that CBS exerted a beneficial effect on EE-induced intrahepatic cholestasis rats by restoring biliary transport function, which may result from the upregulation of PDZK1 expression. PMID:28133487

  13. Store-operated Ca2+ Entry-associated Regulatory factor (SARAF) Plays an Important Role in the Regulation of Arachidonate-regulated Ca2+ (ARC) Channels.

    PubMed

    Albarran, Letizia; Lopez, Jose J; Woodard, Geoffrey E; Salido, Gines M; Rosado, Juan A

    2016-03-25

    The store-operated Ca(2+)entry-associated regulatory factor (SARAF) has recently been identified as a STIM1 regulatory protein that facilitates slow Ca(2+)-dependent inactivation of store-operated Ca(2+)entry (SOCE). Both the store-operated channels and the store-independent arachidonate-regulated Ca(2+)(ARC) channels are regulated by STIM1. In the present study, we show that, in addition to its location in the endoplasmic reticulum, SARAF is constitutively expressed in the plasma membrane, where it can interact with plasma membrane (PM)-resident ARC forming subunits in the neuroblastoma cell line SH-SY5Y. Using siRNA-based and overexpression approaches we report that SARAF negatively regulates store-independent Ca(2+)entry via the ARC channels. Arachidonic acid (AA) increases the association of PM-resident SARAF with Orai1. Finally, our results indicate that SARAF modulates the ability of AA to promote cell survival in neuroblastoma cells. In addition to revealing new insight into the biology of ARC channels in neuroblastoma cells, these findings provide evidence for an unprecedented location of SARAF in the plasma membrane.

  14. The importance of an asymmetric distribution of acidic lipids for synaptotagmin 1 function as a Ca2+ sensor.

    PubMed

    Lai, Ying; Shin, Yeon-Kyun

    2012-04-01

    Syt1 (synaptotagmin 1) is a major Ca2+ sensor for synaptic vesicle fusion. Although Syt1 is known to bind to SNARE (soluble N-ethylmaleimide-sensitive fusion protein-attachment protein receptor) complexes and to the membrane, the mechanism by which Syt1 regulates vesicle fusion is controversial. In the present study we used in vitro lipid-mixing assays to investigate the Ca2+-dependent Syt1 function in proteoliposome fusion. To study the role of acidic lipids, the concentration of negatively charged DOPS (1,2-dioleoyl-sn-glycero-3-phospho-L-serine) in the vesicle was varied. Syt1 stimulated lipid mixing by 3-10-fold without Ca2+. However, with Ca2+ there was an additional 2-5-fold enhancement. This Ca2+-dependent stimulation was observed only when there was excess PS (phosphatidylserine) on the t-SNARE (target SNARE) side. If there was equal or more PS on the v-SNARE (vesicule SNARE) side the Ca2+-dependent stimulation was not observed. We found that Ca2+ at a concentration between 10 and 50 μM was sufficient to give rise to the maximal enhancement. The single-vesicle-fusion assay indicates that the Ca2+-dependent enhancement was mainly on docking, whereas its effect on lipid mixing was small. Thus for Syt1 to function as a Ca2+ sensor, a charge asymmetry appears to be important and this may play a role in steering Syt1 to productively trans bind to the plasma membrane.

  15. Induction of thrombospondin 1 by retinoic acid is important during differentiation of neuroblastoma cells.

    PubMed Central

    Castle, V P; Ou, X; O'Shea, S; Dixit, V M

    1992-01-01

    Neuroblastoma, a malignant neoplasm that arises in the adrenal medulla or sympathetic ganglion, is one of the most common solid tumors of childhood. Reports that neuroblastomas spontaneously mature to form benign ganglioneuromas have prompted investigations into the efficacy of using agents that induce neuronal differentiation in the treatment of this malignancy. Retinoic acid is one agent in particular that has been shown to induce growth inhibition and terminal differentiation of neuroblastoma cell lines in vitro. Using the human neuroblastoma cell line SMH-KCNR, we have investigated the role of the extracellular matrix protein thrombospondin in retinoic acid induced neuroblastoma differentiation. Treatment with retinoic acid results in a rapid induction (within 4 h) of thrombospondin (TSP) message which is independent of intervening protein synthesis and superinducible in the presence of cycloheximide. This suggests that TSP functions as a retinoic acid inducible immediate early response gene. A concomitant increase in both cell associated and soluble forms of TSP protein can be detected within 24 h of retinoic acid treatment. A functional role for TSP in SMH-KCNR differentiation was established in experiments which showed that exposure to anti-TSP monoclonal antibodies delay retinoic acid differentiation for 48 h. At the time the cells overcome the effects of TSP inhibition, laminin production becomes maximal. Treatment of the cells with a combination of anti-TSP and antilaminin antibodies results in complete inhibition of differentiation. Images PMID:1430209

  16. Interaction of myosin VI and its binding partner DOCK7 plays an important role in NGF-stimulated protrusion formation in PC12 cells.

    PubMed

    Sobczak, Magdalena; Chumak, Vira; Pomorski, Paweł; Wojtera, Emilia; Majewski, Łukasz; Nowak, Jolanta; Yamauchi, Junji; Rędowicz, Maria Jolanta

    2016-07-01

    DOCK7 (dedicator of cytokinesis 7) is a guanidine nucleotide exchange factor (GEF) for Rac1 GTPase that is involved in neuronal polarity and axon generation as well in Schwann cell differentiation and myelination. Recently, we identified DOCK7 as the binding partner of unconventional myosin VI (MVI) in neuronal-lineage PC12 cells and postulated that this interaction could be important in vivo [Majewski et al. (2012) Biochem Cell Biol., 90:565-574]. Herein, we found that MVI-DOCK7 interaction takes also place in other cell lines and demonstrated that MVI cargo domain via its RRL motif binds to DOCK7 C-terminal M2 and DHR2 domains. In MVI knockdown cells, lower Rac1 activity and a decrease of DOCK7 phosphorylation on Tyr1118 were observed, indicating that MVI could contribute to DOCK7 activity. MVI and DOCK7 co-localization was maintained during NGF-stimulated PC12 cell differentiation and observed also in the outgrowths. Also, during differentiation an increase in phosphorylation of DOCK7 as well as of its downstream effector JNK kinase was detected. Interestingly, overexpression of GFP-tagged MVI cargo domain (GFP-GT) impaired protrusion formation indicating that full length protein is important for this process. Moreover, a transient increase in Rac activity observed at 5min of NGF-stimulated differentiation of PC12 cells (overexpressing either GFP or GFP-MVI) was not detected in cells overexpressing the cargo domain. These data indicate that MVI-DOCK7 interaction could have functional implications in the protrusion outgrowth, and full length MVI seems to be important for delivery and maintenance of DOCK7 along the protrusions, and exerting its GEF activity.

  17. IGF-1 Signaling Plays an Important Role in the Formation of Three-Dimensional Laminated Neural Retina and Other Ocular Structures From Human Embryonic Stem Cells.

    PubMed

    Mellough, Carla B; Collin, Joseph; Khazim, Mahmoud; White, Kathryn; Sernagor, Evelyne; Steel, David H W; Lako, Majlinda

    2015-08-01

    We and others have previously demonstrated that retinal cells can be derived from human embryonic stem cells (hESCs) and induced pluripotent stem cells under defined culture conditions. While both cell types can give rise to retinal derivatives in the absence of inductive cues, this requires extended culture periods and gives lower overall yield. Further understanding of this innate differentiation ability, the identification of key factors that drive the differentiation process, and the development of clinically compatible culture conditions to reproducibly generate functional neural retina is an important goal for clinical cell based therapies. We now report that insulin-like growth factor 1 (IGF-1) can orchestrate the formation of three-dimensional ocular-like structures from hESCs which, in addition to retinal pigmented epithelium and neural retina, also contain primitive lens and corneal-like structures. Inhibition of IGF-1 receptor signaling significantly reduces the formation of optic vesicle and optic cups, while exogenous IGF-1 treatment enhances the formation of correctly laminated retinal tissue composed of multiple retinal phenotypes that is reminiscent of the developing vertebrate retina. Most importantly, hESC-derived photoreceptors exhibit advanced maturation features such as the presence of primitive rod- and cone-like photoreceptor inner and outer segments and phototransduction-related functional responses as early as 6.5 weeks of differentiation, making these derivatives promising candidates for cell replacement studies and in vitro disease modeling.

  18. Proteomics of Fusarium oxysporum race 1 and race 4 reveals enzymes involved in carbohydrate metabolism and ion transport that might play important roles in banana Fusarium wilt.

    PubMed

    Sun, Yong; Yi, Xiaoping; Peng, Ming; Zeng, Huicai; Wang, Dan; Li, Bo; Tong, Zheng; Chang, Lili; Jin, Xiang; Wang, Xuchu

    2014-01-01

    Banana Fusarium wilt is a soil-spread fungal disease caused by Fusarium oxysporum. In China, the main virulence fungi in banana are F. oxysporum race 1 (F1, weak virulence) and race 4 (F4, strong virulence). To date, no proteomic analyses have compared the two races, but the difference in virulence between F1 and F4 might result from their differentially expressed proteins. Here we report the first comparative proteomics of F1 and F4 cultured under various conditions, and finally identify 99 protein species, which represent 59 unique proteins. These proteins are mainly involved in carbohydrate metabolism, post-translational modification, energy production, and inorganic ion transport. Bioinformatics analysis indicated that among the 46 proteins identified from F4 were several enzymes that might be important for virulence. Reverse transcription PCR analysis of the genes for 15 of the 56 proteins revealed that their transcriptional patterns were similar to their protein expression patterns. Taken together, these data suggest that proteins involved in carbohydrate metabolism and ion transport may be important in the pathogenesis of banana Fusarium wilt. Some enzymes such as catalase-peroxidase, galactosidase and chitinase might contribute to the strong virulence of F4. Overexpression or knockout of the genes for the F4-specific proteins will help us to further understand the molecular mechanism of Fusarium-induced banana wilt.

  19. IGF‐1 Signaling Plays an Important Role in the Formation of Three‐Dimensional Laminated Neural Retina and Other Ocular Structures From Human Embryonic Stem Cells

    PubMed Central

    Mellough, Carla B.; Collin, Joseph; Khazim, Mahmoud; White, Kathryn; Sernagor, Evelyne; Steel, David H. W.

    2015-01-01

    Abstract We and others have previously demonstrated that retinal cells can be derived from human embryonic stem cells (hESCs) and induced pluripotent stem cells under defined culture conditions. While both cell types can give rise to retinal derivatives in the absence of inductive cues, this requires extended culture periods and gives lower overall yield. Further understanding of this innate differentiation ability, the identification of key factors that drive the differentiation process, and the development of clinically compatible culture conditions to reproducibly generate functional neural retina is an important goal for clinical cell based therapies. We now report that insulin‐like growth factor 1 (IGF‐1) can orchestrate the formation of three‐dimensional ocular‐like structures from hESCs which, in addition to retinal pigmented epithelium and neural retina, also contain primitive lens and corneal‐like structures. Inhibition of IGF‐1 receptor signaling significantly reduces the formation of optic vesicle and optic cups, while exogenous IGF‐1 treatment enhances the formation of correctly laminated retinal tissue composed of multiple retinal phenotypes that is reminiscent of the developing vertebrate retina. Most importantly, hESC‐derived photoreceptors exhibit advanced maturation features such as the presence of primitive rod‐ and cone‐like photoreceptor inner and outer segments and phototransduction‐related functional responses as early as 6.5 weeks of differentiation, making these derivatives promising candidates for cell replacement studies and in vitro disease modeling. Stem Cells 2015;33:2416–2430 PMID:25827910

  20. Comparative Analysis of Lipid Content and Fatty Acid Composition of Commercially Important Fish and Shellfish from Sri Lanka and Japan.

    PubMed

    Devadason, Chandravathany; Jayasinghe, Chamila; Sivakanesan, Ramiah; Senarath, Samanthika; Beppu, Fumiaki; Gotoh, Naohiro

    2016-01-01

    Sri Lanka is surrounded by the Indian Ocean, allowing plenty of fishes to be caught. Moreover, these fishes represent one of the undocumented fish resources in the world and their detailed lipid profiles have not been previously examined. In this study, the lipid content and fatty acid composition of 50 commercially important fishes from the Indian Ocean (Sri Lanka) and the Pacific Ocean (Japan) were compared. The total lipid content and fatty acid composition, including eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:6n-3, DHA), differed significantly among species. Fish from the Pacific Ocean had higher proportions of fatty acids, including EPA and DHA. Herrings and mackerels from both oceanic areas demonstrated high levels of EPA and DHA, and n-3/n-6 ratio. Brackish and freshwater fishes from both groups showed low levels of PUFAs. Fish from the Indian Ocean were high in n-6 fatty acids. Monounsaturated fatty acid levels were high in omnivorous fish from the Pacific Ocean, and saturated fatty acid levels were high in fish from the Indian Ocean. The results of this study will be of value in determining the dietary usefulness of fish caught in Sri Lanka.

  1. Steroidogenesis in MA-10 Mouse Leydig Cells Is Altered via Fatty Acid Import into the Mitochondria1

    PubMed Central

    Rone, Malena B.; Midzak, Andrew S.; Martinez-Arguelles, Daniel B.; Fan, Jinjiang; Ye, Xiaoying; Blonder, Josip; Papadopoulos, Vassilios

    2014-01-01

    ABSTRACT Mitochondria are home to many cellular processes, including oxidative phosphorylation and fatty acid metabolism, and in steroid-synthesizing cells, they are involved in cholesterol import and metabolism, which is the initiating step in steroidogenesis. The formation of macromolecular protein complexes aids in the regulation and efficiency of these mitochondrial functions, though because of their dynamic nature, they are hard to identify. To overcome this problem, we used Blue-Native PAGE with whole-gel mass spectrometry on isolated mitochondria from control and hormone-treated MA-10 mouse tumor Leydig cells. The presence of multiple mitochondrial protein complexes was shown. Although these were qualitatively similar under control and human chorionic gonadotropin (hCG)-stimulated conditions, quantitative differences in the components of the complexes emerged after hCG treatment. A prominent decrease was observed with proteins involved in fatty acid import into the mitochondria, implying that mitochondrial beta-oxidation is not essential for steroidogenesis. To confirm this observation, we inhibited fatty acid import utilizing the CPT1a inhibitor etomoxir, resulting in increased steroid production. Conversely, stimulation of mitochondrial beta-oxidation with metformin resulted in a dose-dependent reduction in steroidogenesis. These changes were accompanied by changes in mitochondrial respiration and in the lactic acid formed during glycolysis. Taken together, these results suggest that upon hormonal stimulation, mitochondria efficiently import cholesterol for steroid production at the expense of other lipids necessary for energy production, specifically fatty acids required for beta-oxidation. PMID:25210128

  2. Chicken gga-miR-19a Targets ZMYND11 and Plays an Important Role in Host Defense against Mycoplasma gallisepticum (HS Strain) Infection

    PubMed Central

    Hu, Qingchang; Zhao, Yabo; Wang, Zaiwei; Hou, Yue; Bi, Dingren; Sun, Jianjun; Peng, Xiuli

    2016-01-01

    Mycoplasma gallisepticum (MG), one of the most pathogenic Mycoplasmas, can cause chronic respiratory disease (CRD) in chickens. It has been suggested that micro-ribonucleic acids (miRNAs) are involved in microbial pathogenesis. However, little is known about the roles of miRNAs in MG infection. Previously, we found by deep sequencing that gga-miR-19a was significantly up-regulated in the lungs of MG-infected chicken embryos. In this work, we confirmed that gga-miR-19a was up-regulated in both MG-infected chicken embryonic lungs and MG-infected DF-1 (chicken embryo fibroblast) cells. At 72 h post-transfection, we found that the over-expression of gga-miR-19a significantly enhanced the proliferation of MG-infected DF-1 cells by promoting the transition from the G1 phase to the S and G2 phases, while a gga-miR-19a inhibitor repressed the proliferation of MG-infected DF-1 cells by arresting the cell cycle in the G1 phase. Moreover, we found that gga-miR-19a regulated the expression of the host zinc-finger protein, MYND-type containing 11 (ZMYND11), through binding to its 3′ untranslated region (3′-UTR). DAVID analysis revealed that ZMYND11 could negatively regulate the NF-kappaB (NF-κB) signaling pathway in chickens (Gallus gallus). Upon MG infection, gga-miR-19a, NF-κB, MyD88, and TNF-α were all up-regulated, whereas ZMYND11 was down-regulated. The over-expression of gga-miR-19a in the DF-1 cells did not affect the above gene expression patterns, and gga-miR-19a inhibitor repressed the expression of NF-κB, MyD88, and TNF-α, but enhanced the expression of ZMYND11. In conclusion, gga-miR-19a might suppress the expression of ZMYND11 in MG-infected chicken embryonic lungs and DF-1 cells, activate the NF-κB signaling pathway, and promote pro-inflammatory cytokines expression, the cell cycle progression and cell proliferation to defend against MG infection. PMID:27683641

  3. ‘Serious thigh muscle strains’: beware the intramuscular tendon which plays an important role in difficult hamstring and quadriceps muscle strains

    PubMed Central

    Brukner, Peter; Connell, David

    2016-01-01

    Why do some hamstring and quadriceps strains take much longer to repair than others? Which injuries are more prone to recurrence? Intramuscular tendon injuries have received little attention as an element in ‘muscle strain’. In thigh muscles, such as rectus femoris and biceps femoris, the attached tendon extends for a significant distance within the muscle belly. While the pathology of most muscle injures occurs at a musculotendinous junction, at first glance the athlete appears to report pain within a muscle belly. In addition to the musculotendinous injury being a site of pathology, the intramuscular tendon itself is occasionally injured. These injuries have a variety of appearances on MRIs. There is some evidence that these injuries require a prolonged rehabilitation time and may have higher recurrence rates. Therefore, it is important to recognise the tendon component of a thigh ‘muscle strain’. PMID:26519522

  4. Omp31 plays an important role on outer membrane properties and intracellular survival of Brucella melitensis in murine macrophages and HeLa cells.

    PubMed

    Verdiguel-Fernández, L; Oropeza-Navarro, R; Basurto-Alcántara, Francisco J; Castañeda-Ramírez, A; Verdugo-Rodríguez, Antonio

    2017-04-05

    Brucellosis is an infectious disease that affects practically all species of mammals, including human, and is a major zoonosis worldwide. Brucella spp. are facultative intracellular pathogens that have the ability to survive and multiply in phagocytic and nonphagocytic cells such as trophoblast and epithelial cells. Among the six recognized species of the genus Brucella, Brucella melitensis is the main etiological agent involved in goat brucellosis and is also the most pathogenic for human. It causes significant losses in livestock production as a result of abortions, metritis, infertility, and birth of weak animals. Outer membrane proteins (OMPs) are exposed on the bacterial surface and are in contact with cells and effectors of the host immune response, whereby they could be important virulence factors of Brucella species. To evaluate this hypothesis, the gene encoding for the major outer membrane protein Omp31 was amplified, cloned into pUC18 plasmid, and inactivated by inserting a kanamycin cassette, rendering pLVM31 plasmid which was transformed into B. melitensis wild-type strain to obtain LVM31 mutant strain. The Outer membrane (OM) properties of the mutant strain were compared with B. melitensis Bm133 wild-type and B. melitensis Rev1 vaccine strains, in assessing its susceptibility to polymyxin B, sodium deoxycholate, and nonimmune serum. The mutant strain was assessed in vitro with survival assays in murine macrophages J774.A1 and HeLa cells. Our results demonstrate that LVM31 mutant is more susceptible to polymyxin B, sodium deoxycholate, and nonimmune serum than control strains; moreover, Omp31 mutation caused a decrease in the internalization and a significant decrease in the intracellular survival compared with the reference strains in both cell lines. These results allow us to conclude that Omp31 is important for maintaining OM integrity, but also it is necessary for bacterial internalization, establishment and development of an optimal replication

  5. The importance of lactic acid bacteria for phytate degradation during cereal dough fermentation.

    PubMed

    Reale, Anna; Konietzny, Ursula; Coppola, Raffaele; Sorrentino, Elena; Greiner, Ralf

    2007-04-18

    Lactic acid fermentation of cereal flours resulted in a 100 (rye), 95-100 (wheat), and 39-47% (oat) reduction in phytate content within 24 h. The extent of phytate degradation was shown to be independent from the lactic acid bacteria strain used for fermentation. However, phytate degradation during cereal dough fermentation was positively correlated with endogenous plant phytase activity (rye, 6750 mU g(-1); wheat, 2930 mU g(-1); and oat, 23 mU g(-1)), and heat inactivation of the endogenous cereal phytases prior to lactic acid fermentation resulted in a complete loss of phytate degradation. Phytate degradation was restored after addition of a purified phytase to the liquid dough. Incubation of the cereal flours in buffered solutions resulted in a pH-dependent phytate degradation. The optimum of phytate degradation was shown to be around pH 5.5. Studies on phytase production of 50 lactic acid bacteria strains, previously isolated from sourdoughs, did not result in a significant production of intra- as well as extracellular phytase activity. Therefore, lactic acid bacteria do not participate directly in phytate degradation but provide favorable conditions for the endogenous cereal phytase activity by lowering the pH value.

  6. [Treatment of citrullinemia. Apropos of a case followed from birth. Importance of alpha-ketonic acids].

    PubMed

    Tenenbaum, D; Petion, A M; Desgres, J; Nivelon-Chevallier, A; Gambert, P; Nivelon, J L

    1987-12-01

    From day 1 to day 3, the protein intake of this neonate was restricted to 1 g/kg/d. It included a) essential amino acids (i.e. histidine, lysine, threonine, tryptophan), b) arginine (1,000 mg/d), c) alphaketoisovaleric 500 mg/d, alpha-ketoisocaproic (500 mg/d), alphaketobetamethylvaleric (500 mg/d), alphaketogammamethylthiobutyric (200 mg/d), betaphenylpyruvic (400 mg/d) acids. 250 mg/kg/d of sodium benzoate were given. Caloric and water intakes were 120 cal/kg/d and 120 ml/kg/d respectively. Afterwards, this procedure was modified according to clinical and biological data including serum ammonia and amino acid levels. Alpha-ketonic acid absorption and metabolism were studied on day 29. Both were fast. The detection of alloisoleucine, which is not metabolized was the consequence of the use of alphaketobetamethylvaleric acid. Until the age of 21 months, clinical and metabolic status was satisfactory. At this time, repeated seizures without metabolic failure were accompanied by psychomotor damages.

  7. Mig-14 plays an important role in influencing gene expression of Salmonella enterica serovar Typhi, which contributes to cell invasion under hyperosmotic conditions.

    PubMed

    Sheng, Xiumei; Zhang, Hong; Xia, Qiufeng; Xu, Shungao; Xu, Huaxi; Huang, Xinxiang

    2013-11-01

    mig-14 is a horizontally acquired host-induced virulence gene in Salmonella enterica serovar Typhi. The molecular function of mig-14 is still unknown; sequence analysis showed that mig-14 shared homology with the helix-loop-helix motif of the AraC family of transcriptional regulatory proteins. In our previous microarray-based studies, mig-14 was upregulated at the early stage of high osmotic stress, indicating a potential role under this condition. Therefore, we compared growth and the global transcriptional difference between wild-type and mig-14 mutant strains to identify the role of Mig-14. The results showed that growth of mig-14 mutant strain was clearly slower than that of the wild-type strain, and 148 genes showed significant differences in expression between these two strains under upshift high osmotic treatment for 30 min. In total, 77 genes and 71 genes in the mig-14 mutant strain were upregulated and downregulated, respectively. Genes involved in invasion, virulence, flagellation, motility and chemotaxis of Salmonella were downregulated. Thus, cell invasion abilities of these two strains were further analyzed. The results confirmed that activities of mig-14 were important for cell invasion.

  8. An inhibitor of yeast cyclin-dependent protein kinase plays an important role in ensuring the genomic integrity of daughter cells.

    PubMed Central

    Nugroho, T T; Mendenhall, M D

    1994-01-01

    The gene encoding a 40-kDa protein, previously studied as a substrate and inhibitor of the yeast cyclin-dependent protein kinase, Cdc28, has been cloned. The DNA sequence reveals that p40 is a highly charged protein of 32,187 Da with no significant homology to other proteins. Overexpression of the gene encoding p40, SIC1, produces cells with an elongated but morphology similar to that of cells with depleted levels of the CLB gene products, suggesting that p40 acts as an inhibitor of Cdc28-Clb complexes in vivo. A SIC1 deletion is viable and has highly increased frequencies of broken and lost chromosomes. The deletion strain segregates out many dead cells that are primarily arrested at the G2 checkpoint in an asymmetric fashion. Only daughters and young mothers display the lethal defect, while experienced mothers appear to grow normally. These results suggest that negative regulation of Cdc28 protein kinase activity by p40 is important for faithful segregation of chromosomes to daughter cells. Images PMID:8164683

  9. The presence of Anf/Hesx1 homeobox gene in lampreys suggests that it could play an important role in emergence of telencephalon

    PubMed Central

    Bayramov, Andrey V.; Ermakova, Galina V.; Eroshkin, Fedor M.; Kucheryavyy, Alexandr V.; Martynova, Natalia Y.; Zaraisky, Andrey G.

    2016-01-01

    Accumulated evidence indicates that the core genetic mechanisms regulating early patterning of the brain rudiment in vertebrates are very similar to those operating during development of the anterior region of invertebrate embryos. However, the mechanisms underlying the morphological differences between the elaborate vertebrate brain and its simpler invertebrate counterpart remain poorly understood. Recently, we hypothesized that the emergence of the most anterior unit of the vertebrate brain, the telencephalon, could be related to the appearance in vertebrates’ ancestors of a unique homeobox gene, Anf/Hesx1(further Anf), which is absent from all invertebrates and regulates the earliest steps of telencephalon development in vertebrates. However, the failure of Anf to be detected in one of the most basal extant vertebrate species, the lamprey, seriously compromises this hypothesis. Here, we report the cloning of Anf in three lamprey species and demonstrate that this gene is indeed expressed in embryos in the same pattern as in other vertebrates and executes the same functions by inhibiting the expression of the anterior general regulator Otx2 in favour of the telencephalic regulator FoxG1. These results are consistent with the hypothesis that the Anf homeobox gene may have been important in the evolution of the telencephalon. PMID:28008996

  10. Hypochlorous acid-mediated protein oxidation: how important are chloramine transfer reactions and protein tertiary structure?

    PubMed

    Pattison, David I; Hawkins, Clare L; Davies, Michael J

    2007-08-28

    Hypochlorous acid (HOCl) is a powerful oxidant generated from H2O2 and Cl- by the heme enzyme myeloperoxidase, which is released from activated leukocytes. HOCl possesses potent antibacterial properties, but excessive production can lead to host tissue damage that occurs in numerous human pathologies. As proteins and amino acids are highly abundant in vivo and react rapidly with HOCl, they are likely to be major targets for HOCl. In this study, two small globular proteins, lysozyme and insulin, have been oxidized with increasing excesses of HOCl to determine whether the pattern of HOCl-mediated amino acid consumption is consistent with reported kinetic data for isolated amino acids and model compounds. Identical experiments have been carried out with mixtures of N-acetyl amino acids (to prevent reaction at the alpha-amino groups) that mimic the protein composition to examine the role of protein structure on reactivity. The results indicate that tertiary structure facilitates secondary chlorine transfer reactions of chloramines formed on His and Lys side chains. In light of these data, second-order rate constants for reactions of Lys side chain and Gly chloramines with Trp side chains and disulfide bonds have been determined, together with those for further oxidation of Met sulfoxide by HOCl and His side chain chloramines. Computational kinetic models incorporating these additional rate constants closely predict the experimentally observed amino acid consumption. These studies provide insight into the roles of chloramine formation and three-dimensional structure on the reactions of HOCl with isolated proteins and demonstrate that kinetic models can predict the outcome of HOCl-mediated protein oxidation.

  11. A glutathione-independent glyoxalase of the DJ-1 superfamily plays an important role in managing metabolically generated methylglyoxal in Candida albicans.

    PubMed

    Hasim, Sahar; Hussin, Nur Ahmad; Alomar, Fadhel; Bidasee, Keshore R; Nickerson, Kenneth W; Wilson, Mark A

    2014-01-17

    Methylglyoxal is a cytotoxic reactive carbonyl compound produced by central metabolism. Dedicated glyoxalases convert methylglyoxal to d-lactate using multiple catalytic strategies. In this study, the DJ-1 superfamily member ORF 19.251/GLX3 from Candida albicans is shown to possess glyoxalase activity, making this the first demonstrated glutathione-independent glyoxalase in fungi. The crystal structure of Glx3p indicates that the protein is a monomer containing the catalytic triad Cys(136)-His(137)-Glu(168). Purified Glx3p has an in vitro methylglyoxalase activity (Km = 5.5 mM and kcat = 7.8 s(-1)) that is significantly greater than that of more distantly related members of the DJ-1 superfamily. A close Glx3p homolog from Saccharomyces cerevisiae (YDR533C/Hsp31) also has glyoxalase activity, suggesting that fungal members of the Hsp31 clade of the DJ-1 superfamily are all probable glutathione-independent glyoxalases. A homozygous glx3 null mutant in C. albicans strain SC5314 displays greater sensitivity to millimolar levels of exogenous methylglyoxal, elevated levels of intracellular methylglyoxal, and carbon source-dependent growth defects, especially when grown on glycerol. These phenotypic defects are complemented by restoration of the wild-type GLX3 locus. The growth defect of Glx3-deficient cells in glycerol is also partially complemented by added inorganic phosphate, which is not observed for wild-type or glucose-grown cells. Therefore, C. albicans Glx3 and its fungal homologs are physiologically relevant glutathione-independent glyoxalases that are not redundant with the previously characterized glutathione-dependent GLO1/GLO2 system. In addition to its role in detoxifying glyoxals, Glx3 and its close homologs may have other important roles in stress response.

  12. Cooperative effects of hepatitis B virus and TNF may play important roles in the activation of metabolic pathways through the activation of NF-κB

    PubMed Central

    Wu, Shuang; Kanda, Tatsuo; Nakamoto, Shingo; Jiang, Xia; Nakamura, Masato; Sasaki, Reina; Haga, Yuki; Shirasawa, Hiroshi; Yokosuka, Osamu

    2016-01-01

    Elevated levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β are often observed in the sera of hepatitis B virus (HBV)-infected patients. It is well known that these cytokines activate nuclear factor-κB (NF-κB)-signaling, and are associated with endoplasmic reticulum (ER) stress. We investigated whether HBV or HBV X protein (HBx) enhanced the activation of NF-κB in the presence of TNF and/or IL-1β, and their effects on the expression of metabolic pathway-associated genes. We examined whether HBV or HBx enhanced cytokine-induced activation of NF-κB in hepatocytes, using a reporter assay, in the presence or absence of TNF and/or IL-1β. The expression of insulin-like growth factor binding protein 1 (IGFBP1), one of the NF-κB target genes was also examined. The expression of metabolic pathway-associated genes in HepG2 and HepG2.2.15 cells in the presence or absence of TNF was evaluated by RT-qPCR. Human hepatocytes expressed TNF receptors and IL-1 receptors. NF-κB was activated by cooperation between HBx and TNF in human hepatocytes. We observed IGFBP1 expression in HBV infection and that a number of metabolic pathway-associated genes were upregulated in HepG2.2.15 cells, compared with HepG2 cells with or without TNF treatment. We observed the cooperative effects of HBV and TNF which enhanced the activation of NF-κB as well as upregulated the expression of metabolic pathway-associated genes in hepatocytes. These effects may be important in the development of HBV-associated metabolic syndrome. PMID:27315566

  13. Cooperative effects of hepatitis B virus and TNF may play important roles in the activation of metabolic pathways through the activation of NF-κB.

    PubMed

    Wu, Shuang; Kanda, Tatsuo; Nakamoto, Shingo; Jiang, Xia; Nakamura, Masato; Sasaki, Reina; Haga, Yuki; Shirasawa, Hiroshi; Yokosuka, Osamu

    2016-08-01

    Elevated levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β are often observed in the sera of hepatitis B virus (HBV)-infected patients. It is well known that these cytokines activate nuclear factor-κB (NF-κB)-signaling, and are associated with endoplasmic reticulum (ER) stress. We investigated whether HBV or HBV X protein (HBx) enhanced the activation of NF-κB in the presence of TNF and/or IL-1β, and their effects on the expression of metabolic pathway‑associated genes. We examined whether HBV or HBx enhanced cytokine-induced activation of NF-κB in hepatocytes, using a reporter assay, in the presence or absence of TNF and/or IL-1β. The expression of insulin-like growth factor binding protein 1 (IGFBP1), one of the NF-κB target genes was also examined. The expression of metabolic pathway-associated genes in HepG2 and HepG2.2.15 cells in the presence or absence of TNF was evaluated by RT-qPCR. Human hepatocytes expressed TNF receptors and IL-1 receptors. NF-κB was activated by cooperation between HBx and TNF in human hepatocytes. We observed IGFBP1 expression in HBV infection and that a number of metabolic pathway-associated genes were upregulated in HepG2.2.15 cells, compared with HepG2 cells with or without TNF treatment. We observed the cooperative effects of HBV and TNF which enhanced the activation of NF-κB as well as upregulated the expression of metabolic pathway-associated genes in hepatocytes. These effects may be important in the development of HBV-associated metabolic syndrome.

  14. Domain III of Bacillus thuringiensis Cry1Ie Toxin Plays an Important Role in Binding to Peritrophic Membrane of Asian Corn Borer

    PubMed Central

    Feng, Dongmei; Chen, Zhen; Wang, Zhiwen; Zhang, Chunlu; He, Kanglai; Guo, Shuyuan

    2015-01-01

    The insecticidal IE648 toxin is a truncated Cry1Ie protein with increased toxicity against Asian corn borer (ACB). Cry toxins are pore-forming toxins that disrupt insect midgut cells to kill the larvae. However, the peritrophic membrane (PM) is an important barrier that Cry toxins must cross before binding to midgut cells. Previously, it was shown that Cry toxins are able to bind and accumulate in the PM of several lepidopteran insects. Binding of IE648 toxin to PM of ACB was previously reported and the goal of the current work was the identification of the binding region between Cry1Ie and the PM of ACB. Homologous competition binding assays showed that this interaction was specific. Heterologous competition binding assays performed with different fragments corresponding to domain I, domain II and domain III allowed us to identify that domain III participates in the interaction of IE648 with the PM. Specifically, peptide D3-L8 (corresponding to Cry1Ie toxin residues 607 to 616), located in an exposed loop region of domain III is probably involved in this interaction. Ligand blot assays show that IE648 interact with chitin and PM proteins with sizes of 30, 32 and 80 kDa. The fact that domain III interacts with proteins of similar molecular masses supports that this region of the toxin might be involved in PM interaction. These data provide for the first time the identification of domain III as a putative binding region between PM and 3D-Cry toxin. PMID:26295704

  15. A motif unique to the human DEAD-box protein DDX3 is important for nucleic acid binding, ATP hydrolysis, RNA/DNA unwinding and HIV-1 replication.

    PubMed

    Garbelli, Anna; Beermann, Sandra; Di Cicco, Giulia; Dietrich, Ursula; Maga, Giovanni

    2011-05-12

    DEAD-box proteins are enzymes endowed with nucleic acid-dependent ATPase, RNA translocase and unwinding activities. The human DEAD-box protein DDX3 has been shown to play important roles in tumor proliferation and viral infections. In particular, DDX3 has been identified as an essential cofactor for HIV-1 replication. Here we characterized a set of DDX3 mutants biochemically with respect to nucleic acid binding, ATPase and helicase activity. In particular, we addressed the functional role of a unique insertion between motifs I and Ia of DDX3 and provide evidence for its implication in nucleic acid binding and HIV-1 replication. We show that human DDX3 lacking this domain binds HIV-1 RNA with lower affinity. Furthermore, a specific peptide ligand for this insertion selected by phage display interferes with HIV-1 replication after transduction into HelaP4 cells. Besides broadening our understanding of the structure-function relationships of this important protein, our results identify a specific domain of DDX3 which may be suited as target for antiviral drugs designed to inhibit cellular cofactors for HIV-1 replication.

  16. Playing Teacher.

    ERIC Educational Resources Information Center

    Gilbert, Juan E.

    The acceptance of animation technologies is increasing. Video games, such as Sony PlayStation (SONY, 2002), have become part of the culture for young people from kindergarten through undergraduate school. Animation technologies have been implemented into educational systems in the form of animated pedagogical agents (Johnson, 2000). The research…

  17. Sweet Play

    ERIC Educational Resources Information Center

    Leung, Shuk-kwan S.; Lo, Jane-Jane

    2010-01-01

    This article features Sweet play math, a "math by the month" activity that involves decorating and making sugar cubes. Teachers may want to substitute straws, paper squares, alphabet blocks, or such commercially made manipulatives as Unifix[R] cubes for the real sweets. Given no allergy concerns, teachers and students alike would enjoy some sweet…

  18. Clay Play

    ERIC Educational Resources Information Center

    Rogers, Liz; Steffan, Dana

    2009-01-01

    This article describes how to use clay as a potential material for young children to explore. As teachers, the authors find that their dialogue about the potential of clay as a learning medium raises many questions: (1) What makes clay so enticing? (2) Why are teachers noticing different play and conversation around the clay table as compared to…

  19. The quantitative assessment of the role played by basic amino acid clusters in the nuclear uptake of human ribosomal protein L7

    SciTech Connect

    Tai, Lin-Ru; Chou, Chang-Wei; Lee, I-Fang; Kirby, Ralph; Lin, Alan

    2013-02-15

    In this study, we used a multiple copy (EGFP){sub 3} reporter system to establish a numeric nuclear index system to assess the degree of nuclear import. The system was first validated by a FRAP assay, and then was applied to evaluate the essential and multifaceted nature of basic amino acid clusters during the nuclear import of ribosomal protein L7. The results indicate that the sequence context of the basic cluster determines the degree of nuclear import, and that the number of basic residues in the cluster is irrelevant; rather the position of the pertinent basic residues is crucial. Moreover, it also found that the type of carrier protein used by basic cluster has a great impact on the degree of nuclear import. In case of L7, importin β2 or importin β3 are preferentially used by clusters with a high import efficiency, notwithstanding that other importins are also used by clusters with a weaker level of nuclear import. Such a preferential usage of multiple basic clusters and importins to gain nuclear entry would seem to be a common practice among ribosomal proteins in order to ensure their full participation in high rate ribosome synthesis. - Highlights: ► We introduce a numeric index system that represents the degree of nuclear import. ► The rate of nuclear import is dictated by the sequence context of the basic cluster. ► Importin β2 and β3 were mainly responsible for the N4 mediated nuclear import.

  20. Repurposing lipoic acid changes electron flow in two important metabolic pathways of Escherichia coli.

    PubMed

    Feeney, Morgan Anne; Veeravalli, Karthik; Boyd, Dana; Gon, Stéphanie; Faulkner, Melinda Jo; Georgiou, George; Beckwith, Jonathan

    2011-05-10

    In bacteria, cysteines of cytoplasmic proteins, including the essential enzyme ribonucleotide reductase (RNR), are maintained in the reduced state by the thioredoxin and glutathione/glutaredoxin pathways. An Escherichia coli mutant lacking both glutathione reductase and thioredoxin reductase cannot grow because RNR is disulfide bonded and nonfunctional. Here we report that suppressor mutations in the lpdA gene, which encodes the oxidative enzyme lipoamide dehydrogenase required for tricarboxylic acid (TCA) cycle functioning, restore growth to this redox-defective mutant. The suppressor mutations reduce LpdA activity, causing the accumulation of dihydrolipoamide, the reduced protein-bound form of lipoic acid. Dihydrolipoamide can then provide electrons for the reactivation of RNR through reduction of glutaredoxins. Dihydrolipoamide is oxidized in the process, restoring function to the TCA cycle. Thus, two electron transfer pathways are rewired to meet both oxidative and reductive needs of the cell: dihydrolipoamide functionally replaces glutathione, and the glutaredoxins replace LpdA. Both lipoic acid and glutaredoxins act in the reverse manner from their normal cellular functions. Bioinformatic analysis suggests that such activities may also function in other bacteria.

  1. The importance of n-6/n-3 fatty acids ratio in the major depressive disorder.

    PubMed

    Husted, Kristian Søborg; Bouzinova, Elena V

    2016-01-01

    This review aims to clarify the relation between the ratio of omega-6 to omega-3 fatty acids and the development of depression. It is explained how these fatty acids are involved in the production of eicosanoids and how these fatty acids can affect the membrane fluidity, by their incorporation into membrane phospholipids. In addition, it is described how omega-3 derivatives are shown to regulate gene transcription. In view of the pathophysiology of depression, the mechanisms of how an altered ratio of omega-6 to omega-3 could be involved in depression are discussed. Possible mechanisms could include an increased production of pro-inflammatory cytokines, which can activate the HPA axis and a changed membrane fluidity, which potentially affects membrane bound enzymes, ion channels, receptor activity and neurotransmitter binding. In view of clinical trials, it is also discussed whether omega-3 supplementation could have a beneficial effect in the treatment of depressive patient. There are strong indications that an increased ratio of membrane omega-6 to omega-3 is involved in the pathogenesis of depression and so far, omega-3 supplementation has shown positive effects in clinical trials.

  2. Molecular features of the L-type amino acid transporter 2 determine different import and export profiles for thyroid hormones and amino acids.

    PubMed

    Hinz, Katrin M; Neef, Dominik; Rutz, Claudia; Furkert, Jens; Köhrle, Josef; Schülein, Ralf; Krause, Gerd

    2017-03-05

    The L-type amino acid transporter 2 (LAT2) imports amino acids (AA) and also certain thyroid hormones (TH), e.g. 3,3'-T2 and T3, but not rT3 and T4. We utilized LAT2 mutations (Y130A, N133S, F242W) that increase 3,3'-T2 import and focus here on import and export capacity for AA, T4, T3, BCH and derivatives thereof to delineate molecular features. Transport studies and analysis of competitive inhibition of import by radiolabelled TH and AA were performed in Xenopus laevis oocytes. Only Y130A, a pocket widening mutation, enabled import for T4 and increased it for T3. Mutant F242W showed increased 3,3'-T2 import but no import rates for other TH derivatives. No export was detected for any TH by LAT2-wild type (WT). Mutations Y130A and N133S enabled only the export of 3,3'-T2, while N133S also increased AA export. Thus, distinct molecular LAT2-features determine bidirectional AA transport but only an unidirectional 3,3'-T2 and T3 import.

  3. Functional analysis of amino acids of the Na+/H+ exchanger that are important for proton translocation.

    PubMed

    Wiebe, Christine A; Rieder, Carmen; Young, Paul G; Dibrov, Pavel; Fliegel, Larry

    2003-12-01

    The Na+/H+ exchanger is an integral membrane protein found in the plasma membrane of eukaryotic and prokaryotic cells. In eukaryotes it functions to exchange one proton for a sodium ion. In mammals it removes intracellular protons while in plants and fungal cells the plasma membrane form removes intracellular sodium in exchange for extracellular protons. In this study we used the Na+/H+ exchanger of Schizosaccharomyces pombe (Sod2) as a model system to study amino acids critical for activity of the protein. Twelve mutant forms of the Na+/H+ exchanger were examined for their ability to translocate protons as assessed by a Cytosensor microphysiometer. Mutation of the amino acid Histidine 367 resulted in defective proton translocation. The acidic residues Asp145, Asp178, Asp266 and Asp267 were important in the proton translocation activity of the Na+/H+ exchanger. Mutation of amino acids His98, His233 and Asp241 did not significantly impair proton translocation by the Na+/H+ exchanger. These results confirm that polar amino acids are important in proton flux activity of Na+/H+ exchangers.

  4. Saliva and other taste stimuli are important for gustatory processing of linoleic acid.

    PubMed

    Stratford, Jennifer M; Contreras, Robert J

    2009-10-01

    Paradoxically, bilateral transection of the chorda tympani nerve (CTX) raises the taste discrimination threshold for the free fatty acid, linoleic acid (LA), yet the chorda tympani nerve (CT) is unresponsive to lingual application of LA alone. LA may require a background of saliva to activate taste cells, since CTX decreases saliva production through denervation of the submaxillary and sublingual salivary glands. To assess the role of saliva, we measured LA taste discrimination thresholds for animals whose submaxillary and sublingual salivary glands were removed and also recorded CT responses to LA mixed in artificial saliva. Partial desalivation shifted LA discrimination thresholds from between 5.5 and 11 microM to between 11 and 22 microM. However, this effect was not as pronounced as previously seen with CTX animals. Surprisingly, the CT was unresponsive to LA mixed with artificial saliva, suggesting that artificial saliva may lack components necessary for LA taste. Additionally, fats may primarily enhance other tastes. We previously reported that LA increases CT responses to monosodium glutamate (MSG). Thus we also recorded CT whole nerve responses to taste mixtures of LA and sodium chloride (NaCl), sucrose (SUC), citric acid (CA), or quinine hydrochloride (QHCl) in anesthetized rats. We found that LA increased CT responses to NaCl but did not alter CT responses to SUC, CA, and QHCl. Thus CT recordings either lack the sensitivity to detect small changes to SUC, CA, and QHCl or LA may affect CT responses to MSG and NaCl only, perhaps by specifically modulating gustatory processing of Na(+).

  5. Beyond lipids, pharmacological PPARalpha activation has important effects on amino acid metabolism as studied in the rat.

    PubMed

    Sheikh, Kashif; Camejo, Germán; Lanne, Boel; Halvarsson, Torbjörn; Landergren, Marie Rydén; Oakes, Nicholas D

    2007-04-01

    PPARalpha agonists have been characterized largely in terms of their effects on lipids and glucose metabolism, whereas little has been reported about effects on amino acid metabolism. We studied responses to the PPARalpha agonist WY 14,643 (30 micromol x kg(-1) x day(-1) for 4 wk) in rats fed a saturated fat diet. Plasma and urine were analyzed with proton NMR. Plasma amino acids were measured using HPLC, and hepatic gene expression was assessed with DNA arrays. The high-fat diet elevated plasma levels of insulin and triglycerides (TG), and WY 14,643 treatment ameliorated this insulin resistance and dyslipidemia, lowering plasma insulin and TG levels. In addition, treatment decreased body weight gain, without altering cumulative food intake, and increased liver mass. WY 14,643 increased plasma levels of 12 of 22 amino acids, including glucogenic and some ketogenic amino acids, whereas arginine was significantly decreased. There was no alteration in branched-chain amino acid levels. Compared with the fat-fed control animals, WY 14,643-treated animals had raised plasma urea and ammonia levels as well as raised urine levels of N-methylnicotinamide and dimethylglycine. WY 14,643 induced changes in a number of key genes involved in amino acid metabolism in addition to expected effects on hepatic genes involved in lipid catabolism and ketone body formation. In conclusion, the present results suggest that, in rodents, effects of pharmacological PPARalpha activation extend beyond control of lipid metabolism to include important effects on whole body amino acid mobilization and hepatic amino acid metabolism.

  6. Structure-Function of CD36 and Importance of Fatty Acid Signal Transduction in Fat Metabolism

    PubMed Central

    Pepino, Marta Yanina; Kuda, Ondrej; Samovski, Dmitri; Abumrad, Nada A

    2015-01-01

    CD36 is a scavenger receptor that functions in high affinity tissue uptake of long chain fatty acids (FA) and contributes under excessive fat supply to lipid accumulation and metabolic dysfunction. This review describes recent evidence regarding the CD36 FA binding site and a potential mechanism for FA transfer. It also presents the view that CD36 and FA signaling coordinate fat utilization based on newly identified CD36 actions that involve oral fat perception, intestinal fat absorption, secretion of the peptides cholecystokinin and secretin, regulation of hepatic lipoprotein output, activation of beta oxidation by muscle and regulation of the production of the FA derived bioactive eicosanoids. Thus abnormalities of fat metabolism and the associated pathology might involve dysfunction of CD36-mediated signal transduction in addition to the changes of FA uptake. PMID:24850384

  7. Importance of databases of nucleic acids for bioinformatic analysis focused to genomics

    NASA Astrophysics Data System (ADS)

    Jimenez-Gutierrez, L. R.; Barrios-Hernández, C. J.; Pedraza-Ferreira, G. R.; Vera-Cala, L.; Martinez-Perez, F.

    2016-08-01

    Recently, bioinformatics has become a new field of science, indispensable in the analysis of millions of nucleic acids sequences, which are currently deposited in international databases (public or private); these databases contain information of genes, RNA, ORF, proteins, intergenic regions, including entire genomes from some species. The analysis of this information requires computer programs; which were renewed in the use of new mathematical methods, and the introduction of the use of artificial intelligence. In addition to the constant creation of supercomputing units trained to withstand the heavy workload of sequence analysis. However, it is still necessary the innovation on platforms that allow genomic analyses, faster and more effectively, with a technological understanding of all biological processes.

  8. Importance of accurate spectral simulations for the analysis of terahertz spectra: citric acid anhydrate and monohydrate.

    PubMed

    King, Matthew D; Davis, Eric A; Smith, Tiffany M; Korter, Timothy M

    2011-10-13

    The terahertz (THz) spectra of crystalline solids are typically uniquely sensitive to the molecular packing configurations, allowing for the detection of polymorphs and hydrates by THz spectroscopic techniques. It is possible, however, that coincident absorptions may be observed between related crystal forms, in which case careful assessment of the lattice vibrations of each system must be performed. Presented here is a THz spectroscopic investigation of citric acid in its anhydrous and monohydrate phases. Remarkably similar features were observed in the THz spectra of both systems, requiring the accurate calculation of the low-frequency vibrational modes by solid-state density functional theory to determine the origins of these spectral features. The results of the simulations demonstrate the necessity of reliable and rigorous methods for THz vibrational modes to ensure the proper evaluation of the THz spectra of molecular solids.

  9. The quantitative assessment of the role played by basic amino acid clusters in the nuclear uptake of human ribosomal protein L7.

    PubMed

    Tai, Lin-Ru; Chou, Chang-Wei; Lee, I-Fang; Kirby, Ralph; Lin, Alan

    2013-02-15

    In this study, we used a multiple copy (EGFP)(3) reporter system to establish a numeric nuclear index system to assess the degree of nuclear import. The system was first validated by a FRAP assay, and then was applied to evaluate the essential and multifaceted nature of basic amino acid clusters during the nuclear import of ribosomal protein L7. The results indicate that the sequence context of the basic cluster determines the degree of nuclear import, and that the number of basic residues in the cluster is irrelevant; rather the position of the pertinent basic residues is crucial. Moreover, it also found that the type of carrier protein used by basic cluster has a great impact on the degree of nuclear import. In case of L7, importin β2 or importin β3 are preferentially used by clusters with a high import efficiency, notwithstanding that other importins are also used by clusters with a weaker level of nuclear import. Such a preferential usage of multiple basic clusters and importins to gain nuclear entry would seem to be a common practice among ribosomal proteins in order to ensure their full participation in high rate ribosome synthesis.

  10. Oxidative stress is more important than acid in the pathogenesis of reflux oesophagitis in rats

    PubMed Central

    Oh, T; Lee, J; Ahn, B; Cho, H; Kim, W; Kim, Y; Surh, Y; Cho, S; Lee, K; Hahm, K

    2001-01-01

    BACKGROUND—Although antisecretory medications such as histamine type II receptor antagonists or proton pump inhibitors have been used to treat reflux oesophagitis, a considerable number of patients do not achieve complete mucosal healing or suffer from either sustained symptoms or ensuing complications, suggesting other damaging factors or impaired mucosal resistance are also involved in the pathogenesis of reflux oesophagitis.
AIMS—The present study was designed to evaluate oxidative stress as the major pathogenic factor of reflux oesophagitis and to determine the usefulness of antioxidants in the treatment of reflux oesophagitis.
MATERIALS AND METHODS—Reflux oesophagitis was induced by insertion of a 3 mm calibre ring into the duodenum, 1 cm distal to the ligament of Treitz, in Sprague-Dawley rats.
RESULTS—DA-9601, a novel antioxidant substance, significantly attenuated the gross and histopathological scores of reflux oesophagitis compared with those treated with ranitidine alone or reflux oesophagitis controls in a dose dependent manner. Only scattered erosions were observed in the antioxidant pretreated group but acid suppression by ranitidine was not effective in decreasing the severity of reflux oesophagitis. Significantly increased amounts of malondialdehyde (MDA), increased nuclear factor κB (NFκB) activation, and depletion of reduced glutathione (GSH) were observed in experimentally induced reflux oesophagitis. DA-9601 pretreatment attenuated the decrement in mucosal GSH levels and decreased MDA formation significantly. DA-9601 treatment caused significant reductions in activation of NFκB transcription factor, especially the p50 subunit, in accordance with the significantly higher levels of inhibitory protein of NFκB expression.
CONCLUSION—Reflux oesophagitis caused considerable levels of oxidative stress in the oesophageal mucosa and antioxidant treatment should be considered as supplementary therapy in the prevention or treatment

  11. Growing Up with Play

    ERIC Educational Resources Information Center

    Katch, Jane

    2008-01-01

    Many adults are afraid of boys' play today, believing that the aggression that is so common in boys' fantasies is dangerous and might make them become violent men. This personal reflection describes the importance of multiage play in showing little boys how to become big boys while encouraging empathy and emotional growth in older boys. The author…

  12. Acid-fast lipids are important structural components of oocyst walls of Cryptosporidium, Toxoplasma, and Eimeria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coccidia are protozoan parasites that cause significant human disease and are of major agricultural importance. Cryptosporidium spp.cause diarrhea in humans and animals, while congenital Toxoplasma infections causes blindness and death. Eimeria kills chickens, so all poultry feed contain antibioti...

  13. Relative Importance of Nitrite Oxidation by Hypochlorous Acid under Chloramination Conditions

    EPA Science Inventory

    The importance of nitrite’s oxidation by tree chlorine under chloramination conditions was evaluated using batch kinetic experiments and a chloramine model implemented into the computer program AWUASIM. The experimental data was best represented with the inclusion of a reaction b...

  14. African oil plays

    SciTech Connect

    Clifford, A.J. )

    1989-09-01

    The vast continent of Africa hosts over eight sedimentary basins, covering approximately half its total area. Of these basins, only 82% have entered a mature exploration phase, 9% have had little or no exploration at all. Since oil was first discovered in Africa during the mid-1950s, old play concepts continue to bear fruit, for example in Egypt and Nigeria, while new play concepts promise to become more important, such as in Algeria, Angola, Chad, Egypt, Gabon, and Sudan. The most exciting developments of recent years in African oil exploration are: (1) the Gamba/Dentale play, onshore Gabon; (2) the Pinda play, offshore Angola; (3) the Lucula/Toca play, offshore Cabinda; (4) the Metlaoui play, offshore Libya/Tunisia; (5) the mid-Cretaceous sand play, Chad/Sudan; and (6) the TAG-I/F6 play, onshore Algeria. Examples of these plays are illustrated along with some of the more traditional oil plays. Where are the future oil plays likely to develop No doubt, the Saharan basins of Algeria and Libya will feature strongly, also the presalt of Equatorial West Africa, the Central African Rift System and, more speculatively, offshore Ethiopia and Namibia, and onshore Madagascar, Mozambique, and Tanzania.

  15. Tricarboxylic acid cycle and one-carbon metabolism pathways are important in Edwardsiella ictaluri virulence.

    PubMed

    Dahal, Neeti; Abdelhamed, Hossam; Lu, Jingjun; Karsi, Attila; Lawrence, Mark L

    2013-01-01

    Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of channel catfish (ESC). The disease causes considerable economic losses in the commercial catfish industry in the United States. Although antibiotics are used as feed additive, vaccination is a better alternative for prevention of the disease. Here we report the development and characterization of novel live attenuated E. ictaluri mutants. To accomplish this, several tricarboxylic acid cycle (sdhC, mdh, and frdA) and one-carbon metabolism genes (gcvP and glyA) were deleted in wild type E. ictaluri strain 93-146 by allelic exchange. Following bioluminescence tagging of the E. ictaluri ΔsdhC, Δmdh, ΔfrdA, ΔgcvP, and ΔglyA mutants, their dissemination, attenuation, and vaccine efficacy were determined in catfish fingerlings by in vivo imaging technology. Immunogenicity of each mutant was also determined in catfish fingerlings. Results indicated that all of the E. ictaluri mutants were attenuated significantly in catfish compared to the parent strain as evidenced by 2,265-fold average reduction in bioluminescence signal from all the mutants at 144 h post-infection. Catfish immunized with the E. ictaluri ΔsdhC, Δmdh, ΔfrdA, and ΔglyA mutants had 100% relative percent survival (RPS), while E. ictaluri ΔgcvP vaccinated catfish had 31.23% RPS after re-challenge with the wild type E. ictaluri.

  16. Tricarboxylic Acid Cycle and One-Carbon Metabolism Pathways Are Important in Edwardsiella ictaluri Virulence

    PubMed Central

    Dahal, Neeti; Abdelhamed, Hossam; Lu, Jingjun; Karsi, Attila; Lawrence, Mark L.

    2013-01-01

    Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of channel catfish (ESC). The disease causes considerable economic losses in the commercial catfish industry in the United States. Although antibiotics are used as feed additive, vaccination is a better alternative for prevention of the disease. Here we report the development and characterization of novel live attenuated E. ictaluri mutants. To accomplish this, several tricarboxylic acid cycle (sdhC, mdh, and frdA) and one-carbon metabolism genes (gcvP and glyA) were deleted in wild type E. ictaluri strain 93-146 by allelic exchange. Following bioluminescence tagging of the E. ictaluri ΔsdhC, Δmdh, ΔfrdA, ΔgcvP, and ΔglyA mutants, their dissemination, attenuation, and vaccine efficacy were determined in catfish fingerlings by in vivo imaging technology. Immunogenicity of each mutant was also determined in catfish fingerlings. Results indicated that all of the E. ictaluri mutants were attenuated significantly in catfish compared to the parent strain as evidenced by 2,265-fold average reduction in bioluminescence signal from all the mutants at 144 h post-infection. Catfish immunized with the E. ictaluri ΔsdhC, Δmdh, ΔfrdA, and ΔglyA mutants had 100% relative percent survival (RPS), while E. ictaluri ΔgcvP vaccinated catfish had 31.23% RPS after re-challenge with the wild type E. ictaluri. PMID:23762452

  17. The Basic Leucine Zipper Transcription Factor ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 Is an Important Transcriptional Regulator of Abscisic Acid-Dependent Grape Berry Ripening Processes1[W][OPEN

    PubMed Central

    Nicolas, Philippe; Lecourieux, David; Kappel, Christian; Cluzet, Stéphanie; Cramer, Grant; Delrot, Serge; Lecourieux, Fatma

    2014-01-01

    In grape (Vitis vinifera), abscisic acid (ABA) accumulates during fruit ripening and is thought to play a pivotal role in this process, but the molecular basis of this control is poorly understood. This work characterizes ABSCISIC ACID RESPONSE ELEMENT-BINDING FACTOR2 (VvABF2), a grape basic leucine zipper transcription factor belonging to a phylogenetic subgroup previously shown to be involved in ABA and abiotic stress signaling in other plant species. VvABF2 transcripts mainly accumulated in the berry, from the onset of ripening to the harvesting stage, and were up-regulated by ABA. Microarray analysis of transgenic grape cells overexpressing VvABF2 showed that this transcription factor up-regulates and/or modifies existing networks related to ABA responses. In addition, grape cells overexpressing VvABF2 exhibited enhanced responses to ABA treatment compared with control cells. Among the VvABF2-mediated responses highlighted in this study, the synthesis of phenolic compounds and cell wall softening were the most strongly affected. VvABF2 overexpression strongly increased the accumulation of stilbenes that play a role in plant defense and human health (resveratrol and piceid). In addition, the firmness of fruits from tomato (Solanum lycopersicum) plants overexpressing VvABF2 was strongly reduced. These data indicate that VvABF2 is an important transcriptional regulator of ABA-dependent grape berry ripening. PMID:24276949

  18. Messy Play

    ERIC Educational Resources Information Center

    Feeney, Stephanie; Freeman, Nancy

    2011-01-01

    This article considers the story of 3-year-old Mia and her mother's request that teachers keep Mia away from messy projects. It offers an opportunity to apply the Code, with a special emphasis on its 2011 reaffirmation and update. This revision has sharpened the focus on the importance of nurturing two-way communication between teachers/caregivers…

  19. Ferroptosis, but Not Necroptosis, Is Important in Nephrotoxic Folic Acid-Induced AKI.

    PubMed

    Martin-Sanchez, Diego; Ruiz-Andres, Olga; Poveda, Jonay; Carrasco, Susana; Cannata-Ortiz, Pablo; Sanchez-Niño, Maria D; Ruiz Ortega, Marta; Egido, Jesus; Linkermann, Andreas; Ortiz, Alberto; Sanz, Ana B

    2017-01-01

    AKI is histologically characterized by necrotic cell death and inflammation. Diverse pathways of regulated necrosis have been reported to contribute to AKI, but the molecular regulators involved remain unclear. We explored the relative contributions of ferroptosis and necroptosis to folic acid (FA)-induced AKI in mice. FA-AKI in mice associates with lipid peroxidation and downregulation of glutathione metabolism proteins, features that are typical of ferroptotic cell death. We show that ferrostatin-1 (Fer-1), an inhibitor of ferroptosis, preserved renal function and decreased histologic injury, oxidative stress, and tubular cell death in this model. With respect to the immunogenicity of ferroptosis, Fer-1 prevented the upregulation of IL-33, an alarmin linked to necroptosis, and other chemokines and cytokines and prevented macrophage infiltration and Klotho downregulation. In contrast, the pancaspase inhibitor zVAD-fmk did not protect against FA-AKI. Additionally, although FA-AKI resulted in increased protein expression of the necroptosis mediators receptor-interacting protein kinase 3 (RIPK3) and mixed lineage domain-like protein (MLKL), targeting necroptosis with the RIPK1 inhibitor necrostatin-1 or genetic deficiency of RIPK3 or MLKL did not preserve renal function. Indeed, compared with wild-type mice, MLKL knockout mice displayed more severe AKI. However, RIPK3 knockout mice with AKI had less inflammation than their wild-type counterparts, and this effect associated with higher IL-10 concentration and regulatory T cell-to-leukocyte ratio in RIPK3 knockout mice. These data suggest that ferroptosis is the primary cause of FA-AKI and that immunogenicity secondary to ferroptosis may further worsen the damage, although necroptosis-related proteins may have additional roles in AKI.

  20. mTOR inactivation by ROS-JNK-p53 pathway plays an essential role in psedolaric acid B induced autophagy-dependent senescence in murine fibrosarcoma L929 cells.

    PubMed

    Qi, Min; Zhou, Haiyan; Fan, Simiao; Li, Zhao; Yao, Guodong; Tashiro, Shin-Ichi; Onodera, Satoshi; Xia, Mingyu; Ikejima, Takashi

    2013-09-05

    Pseudolaric acid B (PAB), the primary biologically active compound isolated from the root bark of P. kaempferi Gordon, has been reported to exhibit anti-tumor effect primarily via cell cycle arrest and apoptosis. Our previous study demonstrated that PAB triggered mitotic catastrophe in L929 cells. In addition, a small percentage of the cells undergoing mitotic catastrophe displayed an apoptotic phenotype. Therefore, we continued to investigate the fate of the other cells. The results indicated that PAB induced senescence through p19-p53-p21 and p16-Rb pathways in L929 cells. PAB also triggered autophagy via inhibiting Akt-mammalian target of rapamycin (mTOR) activity in L929 cells. In addition, autophagy was demonstrated to reinforce senescence through regulating the senescence pathways. Thus, we focused on the detailed molecular mechanisms whereby autophagy promoted senescence. Reactive oxygen species (ROS) plays an important in autophagy and senescence. We found that PAB triggered a ROS-JNK-p53 positive feedback loop and this feedback loop played a crucial role in autophagy via repressing the activation of mTOR. Furthermore, ROS-JNK-p53 positive feedback loop was demonstrated to regulate senescence. Tuberous sclerosis proteins1 and 2, also known as TSC1 and TSC2, form a protein-complex. TSC1/TSC2 heterodimer is a downstream target of growth factor-phosphoinositide 3-kinase-Akt signaling which negatively regulates mTOR activity. Activation of mTOR by insulin or inhibition of endogenous TSC2 levels by siRNA obviously delayed PAB-induced senescence. In conclusion, mTOR inactivation by ROS-JNK-p53 pathway played an important role in autophagy-dependent senescence in PAB-treated L929 cells.

  1. Structure-activity relationship of ochratoxin A and synthesized derivatives: importance of amino acid and halogen moiety for cytotoxicity.

    PubMed

    Rottkord, Ulrike; Röhl, Christopher; Ferse, Ines; Schulz, Marie-Christin; Rückschloss, Uwe; Gekle, Michael; Schwerdt, Gerald; Humpf, Hans-Ulrich

    2017-03-01

    The enigma why the mycotoxin ochratoxin A (OTA) impairs cell and organ function is still not solved. However, an interaction with target molecules is a prerequisite for any observed adverse effect. This interaction depends on characteristics of the target molecule as well as on the OTA molecule itself. OTA has different structural moieties which may be relevant for these interrelations including a halogen (chlorine) and an amino acid group (phenylalanine). To test their importance for the impact of OTA, detailed structure-activity studies with various OTA derivatives were performed. For this, 23 OTA derivatives were available, which were modified by either an exchange of the halogen moiety against another halogen (fluorine, iodine or bromine) or by the amino acid moiety against another one (tyrosine or alanine) or a combination of both. Additionally, the configuration of the 3R carbon atom was changed to 3S. These derivatives were tested in human renal cells for their ability to induce cell death (cytotoxicity, apoptosis, necrosis), their impact on collagen protein secretion and for their influence on gene expression. It turned out that the substitution of the amino acid moiety against tyrosine or alanine almost completely prevented the adverse effects of OTA. The exchange of the halogen moiety had minor effects and the inversion of the stereochemistry at C3 did not prevent the effects of OTA. Therefore, we conclude that the amino acid moiety of OTA is indispensable for the interaction of OTA with its target molecules.

  2. Chiral separation of the clinically important compounds fucose and pipecolic acid using CE: determination of the most effective chiral selector.

    PubMed

    Hadjistasi, Christoforos A; Stavrou, Ioannis J; Stefan-Van Staden, Raluca-Ioana; Aboul-Enein, Hassan Y; Kapnissi-Christodoulou, Constantina P

    2013-09-01

    In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC-Cl) and 5-amino-2-naphthalene-sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10-mM β-cyclodextrin was able to separate the enantiomers of ANSA-DL-fucose and the polymeric surfactant poly(sodium N-undecanoyl-LL-leucine-valinate) was able to separate the enantiomers of FMOC-DL-pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D-alanine tert-butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers.

  3. Identification of Critical Amino Acids within the Nucleoprotein of Tacaribe Virus Important for Anti-interferon Activity*

    PubMed Central

    Harmon, Brooke; Kozina, Carol; Maar, Dianna; Carpenter, Timothy S.; Branda, Catherine S.; Negrete, Oscar A.; Carson, Bryan D.

    2013-01-01

    The arenavirus nucleoprotein (NP) can suppress induction of type I interferon (IFN). This anti-IFN activity is thought to be shared by all arenaviruses with the exception of Tacaribe virus (TCRV). To identify the TCRV NP amino acid residues that prevent its IFN-countering ability, we created a series of NP chimeras between residues of TCRV NP and Pichinde virus (PICV) NP, an arenavirus NP with potent anti-IFN function. Chimera NP analysis revealed that a minimal four amino acid stretch derived from PICV NP could impart efficient anti-IFN activity to TCRV NP. Strikingly, the TCRV NP gene cloned and sequenced from viral stocks obtained through National Institutes of Health Biodefense and Emerging Infections (BEI) resources deviated from the reference sequence at this particular four-amino acid region, GPPT (GenBank KC329849) versus DLQL (GenBank NC004293), respectively at residues 389–392. When efficiently expressed in cells through codon-optimization, TCRV NP containing the GPPT residues rescued the antagonistic IFN function. Consistent with cell expression results, TCRV infection did not stimulate an IFNβ response early in infection in multiple cells types (e.g. A549, P388D1), and IRF-3 was not translocated to the nucleus in TCRV-infected A549 cells. Collectively, these data suggest that certain TCRV strain variants contain the important NP amino acids necessary for anti-IFN activity. PMID:23382389

  4. Identification of amino acids important for binding of Clostridium perfringens epsilon toxin to host cells and to HAVCR1

    PubMed Central

    Ivie, Susan E.; McClain, Mark S.

    2012-01-01

    Clostridium perfringens epsilon toxin belongs to the aerolysin-like family of pore-forming toxins and is one of the most potent bacterial toxins known. The epsilon toxin causes fatal enterotoxemia in sheep, goats, and possibly humans. Evidence indicates that the toxin binds to protein receptors including hepatitis A virus cellular receptor 1 (HAVCR1), but the region of the toxin responsible for cell binding has not been identified. In the present study, we identify amino acids within the epsilon toxin important for this cell interaction. Site-specific mutagenesis was used to investigate the role of a surface-accessible cluster of aromatic amino acids, and purified mutant proteins were tested in a series of cell-culture assays to assess cytotoxic activity and cell binding. When added to cells, four mutant proteins (Etx-Y29E, Etx-Y30E, Etx-Y36E and Etx-Y196E) were severely impaired in their ability to not only kill host cells, but also in their ability to permeabilize the plasma membrane. Circular dichroism spectroscopy and thermal stability studies revealed that the wild-type and mutant proteins were similarly folded. Additional experiments revealed that these mutant proteins were defective in binding to host cells and to HAVCR1. These data indicate that an amino acid motif including Y29, Y30, Y36, and Y196 is important for the ability of epsilon toxin to interact with cells and HAVCR1. PMID:22938730

  5. Ellagic acid plays a protective role against UV-B-induced oxidative stress by up-regulating antioxidant components in human dermal fibroblasts

    PubMed Central

    Baek, Beomyeol; Lee, Su Hee; Lim, Hye-Won

    2016-01-01

    Ellagic acid (EA), an antioxidant polyphenolic constituent of plant origin, has been reported to possess diverse pharmacological properties, including anti-inflammatory, anti-tumor and immunomodulatory activities. This work aimed to clarify the skin anti-photoaging properties of EA in human dermal fibroblasts. The skin anti-photoaging activity was evaluated by analyzing the reactive oxygen species (ROS), matrix metalloproteinase-2 (MMP-2), total glutathione (GSH) and superoxide dismutase (SOD) activity levels as well as cell viability in dermal fibroblasts under UV-B irradiation. When fibroblasts were exposed to EA prior to UV-B irradiation, EA suppressed UV-B-induced ROS and proMMP-2 elevation. However, EA restored total GSH and SOD activity levels diminished in fibroblasts under UV-B irradiation. EA had an up-regulating activity on the UV-B-reduced Nrf2 levels in fibroblasts. EA, at the concentrations used, was unable to interfere with cell viabilities in both non-irradiated and irradiated fibroblasts. In human dermal fibroblasts, EA plays a defensive role against UV-B-induced oxidative stress possibly through an Nrf2-dependent pathway, indicating that this compound has potential skin antiphotoaging properties. PMID:27162481

  6. Hexameric RSF1010 helicase RepA: the structural and functional importance of single amino acid residues

    PubMed Central

    Ziegelin, Günter; Niedenzu, Timo; Lurz, Rudi; Saenger, Wolfram; Lanka, Erich

    2003-01-01

    In the known monoclinic crystals the 3-dimensional structure of the hexameric, replicative helicase RepA encoded by plasmid RSF1010 shows 6-fold rotational symmetry. In contrast, in the cubic crystal form at 2.55 Å resolution described here RepA has 3-fold symmetry and consists of a trimer of dimers. To study structure–function relationships, a series of repA deletion mutants and mutations yielding single amino acid exchanges were constructed and the respective gene products were analyzed in vivo and in vitro. Hexamerization of RepA occurs via the N-terminus and is required for NTP hydrolysis. The C-terminus is essential both for the interaction with the replication machinery and for the helicase activity. Functional analyses of RepA variants with single amino acid exchanges confirmed most of the predictions that were based on the published 3-dimensional structure. Of the five motifs conserved in family 4 helicases, all residues conserved in RepA and T7 gp4 helicases participate in DNA unwinding. Residues K42, E76, D77, D139 and H178, proposed to play key roles in catalyzing the hydrolysis of NTPs, are essential for RepA activity. Residue H178 of motif H3 couples nucleotide consumption to DNA strand separation. PMID:14530440

  7. Identification of two amino acids within E2 important for the pathogenicity of chimeric classical swine fever virus.

    PubMed

    Wu, Rui; Li, Ling; Zhao, Yu; Tu, Jun; Pan, Zishu

    2016-01-04

    Our previous study demonstrated that a chimeric classical swine fever virus (CSFV) vSM/CE2 containing the E2 gene of the vaccine C-strain on the genetic background of the virulent CSFV strain Shimen (vSM) was attenuated in swine but reversed to virulence after serial passages in PK15 cells. To investigate the molecular basis of the pathogenicity, the genome of the 11th passage vSM/CE2 variant (vSM/CE2-p11) was sequenced, and two amino acid mutations, T745I and M979K, within E2 of vSM/CE2-p11 were observed. Based on reverse genetic manipulation of the chimeric cDNA clone pSM/CE2, the mutated viruses vSM/CE2/T745I, vSMCE2/M979K and vSM/CE2/T745I;M979K were rescued. The data from infection of pigs demonstrated that the M979K amino acid substitution was responsible for pathogenicity. Studies in vitro indicated that T745I and M979K increased infectious virus production and replication. Our results indicated that two residues located at sites 745 and 979 within E2 play a key role in determining the replication in vitro and pathogenicity in vivo of chimeric CSFV vSM/CE2.

  8. Synthesis, structure and DFT study of a chelidamic acid based Cu coordination polymer: On the importance of π-π interactions and hexameric water clusters

    NASA Astrophysics Data System (ADS)

    Mirzaei, Masoud; Eshtiagh-Hosseini, Hossein; Karrabi, Zahra; Notash, Behrouz; Bauzá, Antonio; Frontera, Antonio

    2015-01-01

    One-dimensional coordination polymer, i.e., {(Hampy)[Cu(chel)(H2O)]ṡ2H2O}n (1, ampy = 2-amino-6-methylpyridine, H3chel = chelidamic acid), has been synthesized and characterized by elemental analysis, IR spectroscopy, solution studies and X-ray single-crystal diffraction. In the monomeric unit of compound 1 the metal center exhibits a distorted square-pyramidal coordination sphere. The Cu(II) ion is coordinated to chelidamic acid and water. These monomers are interlinked generating a 1D polymer by means of the para hydroxyl group of the ligand. Protonated 2-amino-6-methylpyridine rings act as counter cations. The crystal lattice is aggregated through intermolecular interactions, such as electrostatic attraction, N-H⋯O, O-H⋯O and C-H⋯O hydrogen bonding and aromatic π stacking interactions. Hydrogen bond interactions between the water molecules led to formation of six-membered rings with chair conformation. These assemblies are described and analyzed by means of density functional theory (DFT) calculations since they play an important role in the construction of three-dimensional supramolecular frameworks.

  9. Electrostatic interactions play an essential role in the binding of oleic acid with α-lactalbumin in the HAMLET-like complex: a study using charge-specific chemical modifications.

    PubMed

    Xie, Yongjing; Min, Soyoung; Harte, Níal P; Kirk, Hannah; O'Brien, John E; Voorheis, H Paul; Svanborg, Catharina; Hun Mok, K

    2013-01-01

    Human α-lactalbumin made lethal to tumor cells (HAMLET) and its analogs are partially unfolded protein-oleic acid (OA) complexes that exhibit selective tumoricidal activity normally absent in the native protein itself. To understand the nature of the interaction between protein and OA moieties, charge-specific chemical modifications of lysine side chains involving citraconylation, acetylation, and guanidination were employed and the biophysical and biological properties were probed. Upon converting the original positively-charged lysine residues to negatively-charged citraconyl or neutral acetyl groups, the binding of OA to protein was eliminated, as were any cytotoxic activities towards osteosarcoma cells. Retention of the positive charges by converting lysine residues to homoarginine groups (guanidination); however, yielded unchanged binding of OA to protein and identical tumoricidal activity to that displayed by the wild-type α-lactalbumin-oleic acid complex. With the addition of OA, the wild-type and guanidinated α-lactalbumin proteins underwent substantial conformational changes, such as partial unfolding, loss of tertiary structure, but retention of secondary structure. In contrast, no significant conformational changes were observed in the citraconylated and acetylated α-lactalbumins, most likely because of the absence of OA binding. These results suggest that electrostatic interactions between the positively-charged basic groups on α-lactalbumin and the negatively-charged carboxylate groups on OA molecules play an essential role in the binding of OA to α-lactalbumin and that these interactions appear to be as important as hydrophobic interactions.

  10. Play and Positive Group Dynamics

    ERIC Educational Resources Information Center

    Thompson, Pam; White, Samantha

    2010-01-01

    Play is an important part of a child's life and essential to learning and development (Vygotsky, 1978). It is vital that students participate in play and that play be conducted in a restorative manner. Play allows a variety of group dynamics to emerge. Irvin Yalom (1995) identifies 11 curative factors of the group experience. These factors include…

  11. Importance of the proline-rich multimerization domain on the oligomerization and nucleic acid binding properties of HIV-1 Vif.

    PubMed

    Bernacchi, Serena; Mercenne, Gaëlle; Tournaire, Clémence; Marquet, Roland; Paillart, Jean-Christophe

    2011-03-01

    The HIV-1 viral infectivity factor (Vif) is required for productive infection of non-permissive cells, including most natural HIV-1 targets, where it counteracts the antiviral activities of the cellular cytosine deaminases APOBEC-3G (A3G) and A3F. Vif is a multimeric protein and the conserved proline-rich domain (161)PPLP(164) regulating Vif oligomerization is crucial for its function and viral infectivity. Here, we expressed and purified wild-type Vif and a mutant protein in which alanines were substituted for the proline residues of the (161)PPLP(164) domain. Using dynamic light scattering, circular dichroism and fluorescence spectroscopy, we established the impact of these mutations on Vif oligomerization, secondary structure content and nucleic acids binding properties. In vitro, wild-type Vif formed oligomers of five to nine proteins, while Vif AALA formed dimers and/or trimers. Up to 40% of the unbound wild-type Vif protein appeared to be unfolded, but binding to the HIV-1 TAR apical loop promoted formation of β-sheets. Interestingly, alanine substitutions did not significantly affect the secondary structure of Vif, but they diminished its binding affinity and specificity for nucleic acids. Dynamic light scattering showed that Vif oligomerization, and interaction with folding-promoting nucleic acids, favor formation of high molecular mass complexes. These properties could be important for Vif functions involving RNAs.

  12. Formic acid catalyzed hydrolysis of SO3 in the gas phase: a barrierless mechanism for sulfuric acid production of potential atmospheric importance.

    PubMed

    Hazra, Montu K; Sinha, Amitabha

    2011-11-02

    Computational studies at the B3LYP/6-311++G(3df,3pd) and MP2/6-311++G(3df,3pd) levels are performed to explore the changes in reaction barrier height for the gas phase hydrolysis of SO(3) to form H(2)SO(4) in the presence of a single formic acid (FA) molecule. For comparison, we have also performed calculations for the reference reaction involving water assisted hydrolysis of SO(3) at the same level. Our results show that the FA assisted hydrolysis of SO(3) to form H(2)SO(4) is effectively a barrierless process. The barrier heights for the isomerization of the SO(3)···H(2)O···FA prereactive collision complex, which is the rate limiting step in the FA assisted hydrolysis, are found to be respectively 0.59 and 0.08 kcal/mol at the B3LYP/6-311++G(3df,3pd) and MP2/6-311++G(3df,3pd) levels. This is substantially lower than the ~7 kcal/mol barrier for the corresponding step in the hydrolysis of SO(3) by two water molecules--which is currently the accepted mechanism for atmospheric sulfuric acid production. Simple kinetic analysis of the relative rates suggests that the reduction in barrier height facilitated by FA, combined with the greater stability of the prereactive SO(3)···H(2)O···FA collision complex compared to SO(3)···H(2)O···H(2)O and the rather plentiful atmospheric abundance of FA, makes the formic acid mediated hydrolysis reaction a potentially important pathway for atmospheric sulfuric acid production.

  13. Importance of Poly(lactic-co-glycolic acid) in Scaffolds for Guided Bone Regeneration: A Focused Review.

    PubMed

    Castillo-Dalí, Gabriel; Velázquez-Cayón, Rocío; Serrera-Figallo, M Angeles; Rodríguez-González-Elipe, Agustín; Gutierrez-Pérez, José-Luis; Torres-Lagares, Daniel

    2015-08-01

    Total or partial tissue damage and loss of function in an organ are two of the most serious and costly issues in human health. Initially, these problems were approached through organ and allogenic tissue transplantation, but this option is limited by the scarce availability of donors. In this manner, new bone for restoring or replacing lost and damaged bone tissue is an important health and socioeconomic necessity. Tissue engineering has been used as a strategy during the 21st century for mitigating this need through the development of guided bone regeneration scaffold and composites. In this manner, compared with other traditional methods, bone tissue engineering offers a new and interesting approach to bone repair. The poly-α-hydroxy acids, which include the copolymers of lactic acid and glycolic acid, have been used commonly in the fabrication of these scaffolds. The objective of our article was to review the characteristics and functions of scaffold with biomedical applications, with special interest in scaffold construction using poly(lactic-co-glycolic acid) polymers, in order to update the current methods used for fabrication and to improve the quality of these scaffolds, integrating this information into the context of advancements made in tissue engineering based on these structures. In the future, research into bone regeneration should be oriented toward a fruitful exchange between disciplines involved in tissue engineering, which is coming very close to filling the gaps in our ability to provide implants and restoration of functionality in bone tissue. Overcoming this challenge will provide benefits to a major portion of the population and facilitate substantial improvements to quality of life.

  14. p38 MAPK Is Activated but Does Not Play a Key Role during Apoptosis Induction by Saturated Fatty Acid in Human Pancreatic β-Cells

    PubMed Central

    Šrámek, Jan; Němcová-Fürstová, Vlasta; Balušíková, Kamila; Daniel, Petr; Jelínek, Michael; James, Roger F.; Kovář, Jan

    2016-01-01

    Saturated stearic acid (SA) induces apoptosis in the human pancreatic β-cells NES2Y. However, the molecular mechanisms involved are unclear. We showed that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway in these cells. Therefore, we tested the role of p38 MAPK signaling pathway activation in apoptosis induction by SA in NES2Y cells. Crosstalk between p38 MAPK pathway activation and accompanying ERK pathway inhibition after SA application was also tested. The inhibition of p38 MAPK expression by siRNA silencing resulted in a decrease in MAPKAPK-2 activation after SA application, but it had no significant effect on cell viability or the level of phosphorylated ERK pathway members. The inhibition of p38 MAPK activity by the specific inhibitor SB202190 resulted in inhibition of MAPKAPK-2 activation and noticeable activation of ERK pathway members after SA treatment but in no significant effect on cell viability. p38 MAPK overexpression by plasmid transfection produced an increase in MAPKAPK-2 activation after SA exposure but no significant influence on cell viability or ERK pathway activation. The activation of p38 MAPK by the specific activator anisomycin resulted in significant activation of MAPKAPK-2. Concerning the effect on cell viability, application of the activator led to apoptosis induction similar to application of SA (PARP cleavage and caspase-7, -8, and -9 activation) and in inhibition of ERK pathway members. We demonstrated that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway and that this activation could be involved in apoptosis induction by SA in the human pancreatic β-cells NES2Y. However, this involvement does not seem to play a key role. Crosstalk between p38 MAPK pathway activation and ERK pathway inhibition in NES2Y cells seems likely. Thus, the ERK pathway inhibition by p38 MAPK activation does not also seem to be essential for SA-induced apoptosis. PMID:26861294

  15. The fatty acid beta-oxidation pathway is important for decidualization of endometrial stromal cells in both humans and mice.

    PubMed

    Tsai, Jui-He; Chi, Maggie M-Y; Schulte, Maureen B; Moley, Kelle H

    2014-02-01

    Embryo implantation and development requires the endometrial stromal cells (ESCs) to undergo decidualization. This differentiation process requires glucose utilization, and blockade of the pentose phosphate pathway inhibits decidualization of ESCs both in vitro and in vivo. Glucose and fatty acids are energy substrates for many cell types, and fatty acid beta-oxidation is critical for embryo implantation. Here, we investigated whether beta-oxidation is required for decidualization of ESCs. As assessed by marker gene expression, decidualization of human primary ESCs was blocked by reducing activity of carnitine calmitoyltransferase I, the rate-limiting enzyme in beta-oxidation, either by short hairpin RNA-mediated silencing or by treatment with the inhibitor etomoxir. Ranolazine (RAN), a partial beta-oxidation inhibitor, blocked early decidualization of a human ESC line. However, decidualization resumed after several days, most likely due to a compensatory up-regulation of GLUT1 expression and an increase in glucose metabolism. Simultaneous inhibition of the beta-oxidation pathway with RAN and the pentose phosphate pathway with glucosamine (GlcN) impaired in vitro decidualization of human ESCs more strongly than inhibition of either pathway alone. These findings were confirmed in murine ESCs in vitro, and exposure to RAN plus GlcN inhibited decidualization in vivo in a deciduoma model. Finally, intrauterine implantation of time-release RAN and GlcN pellets reduced pup number. Importantly, pup number returned to normal after the end of the pellet-active period. This work indicates that both fatty acids and glucose metabolism pathways are important for ESC decidualization, and suggests novel pathways to target for the design of future nonhormonal contraceptives.

  16. Pretend Play and Creative Processes

    ERIC Educational Resources Information Center

    Russ, Sandra W.; Wallace, Claire E.

    2013-01-01

    The authors contend that many cognitive abilities and affective processes important in creativity also occur in pretend play and that pretend play in childhood affects the development of creativity in adulthood. They discuss a variety of theories and observations that attempt to explain the importance of pretend play to creativity. They argue that…

  17. SNAT2 amino acid transporter is regulated by amino acids of the SLC6 gamma-aminobutyric acid transporter subfamily in neocortical neurons and may play no role in delivering glutamine for glutamatergic transmission.

    PubMed

    Grewal, Sukhjeevan; Defamie, Norah; Zhang, Xiong; De Gois, Stéphanie; Shawki, Ali; Mackenzie, Bryan; Chen, Chu; Varoqui, Hélène; Erickson, Jeffrey D

    2009-04-24

    System A transporters SNAT1 and SNAT2 mediate uptake of neutral alpha-amino acids (e.g. glutamine, alanine, and proline) and are expressed in central neurons. We tested the hypothesis that SNAT2 is required to support neurotransmitter glutamate synthesis by examining spontaneous excitatory activity after inducing or repressing SNAT2 expression for prolonged periods. We stimulated de novo synthesis of SNAT2 mRNA and increased SNAT2 mRNA stability and total SNAT2 protein and functional activity, whereas SNAT1 expression was unaffected. Increased endogenous SNAT2 expression did not affect spontaneous excitatory action-potential frequency over control. Long term glutamine exposure strongly repressed SNAT2 expression but increased excitatory action-potential frequency. Quantal size was not altered following SNAT2 induction or repression. These results suggest that spontaneous glutamatergic transmission in pyramidal neurons does not rely on SNAT2. To our surprise, repression of SNAT2 activity was not limited to System A substrates. Taurine, gamma-aminobutyric acid, and beta-alanine (substrates of the SLC6 gamma-aminobutyric acid transporter family) repressed SNAT2 expression more potently (10x) than did System A substrates; however, the responses to System A substrates were more rapid. Since ATF4 (activating transcription factor 4) and CCAAT/enhancer-binding protein are known to bind to an amino acid response element within the SNAT2 promoter and mediate induction of SNAT2 in peripheral cell lines, we tested whether either factor was similarly induced by amino acid deprivation in neurons. We found that glutamine and taurine repressed the induction of both transcription factors. Our data revealed that SNAT2 expression is constitutively low in neurons under physiological conditions but potently induced, together with the taurine transporter TauT, in response to depletion of neutral amino acids.

  18. Redox regulation of protein tyrosine phosphatase 1B (PTP1B): Importance of steric and electronic effects on the unusual cyclization of the sulfenic acid intermediate to a sulfenyl amide

    NASA Astrophysics Data System (ADS)

    Sarma, Bani Kanta

    2013-09-01

    The redox regulation of protein tyrosine phosphatase 1B (PTP1B) via the unusual transformation of its sulfenic acid (PTP1B-SOH) to a cyclic sulfenyl amide intermediate is studied by using small molecule chemical models. These studies suggest that the sulfenic acids derived from the H2O2-mediated reactions o-amido thiophenols do not efficiently cyclize to sulfenyl amides and the sulfenic acids produced in situ can be trapped by using methyl iodide. Theoretical calculations suggest that the most stable conformer of such sulfenic acids are stabilized by nO → σ*S-OH orbital interactions, which force the -OH group to adopt a position trans to the S⋯O interaction, leading to an almost linear arrangement of the O⋯S-O moiety and this may be the reason for the slow cyclization of such sulfenic acids to their corresponding sulfenyl amides. On the other hand, additional substituents at the 6-position of o-amido phenylsulfenic acids that can induce steric environment and alter the electronic properties around the sulfenic acid moiety by S⋯N or S⋯O nonbonded interactions destabilize the sulfenic acids by inducing strain in the molecule. This may lead to efficient the cyclization of such sulfenic acids. This model study suggests that the amino acid residues in the close proximity of the sulfenic acid moiety in PTP1B may play an important role in the cyclization of PTP1B-SOH to produce the corresponding sulfenyl amide.

  19. Mfsd2a Is a Transporter for the Essential ω-3 Fatty Acid Docosahexaenoic Acid (DHA) in Eye and Is Important for Photoreceptor Cell Development.

    PubMed

    Wong, Bernice H; Chan, Jia Pei; Cazenave-Gassiot, Amaury; Poh, Rebecca W; Foo, Juat Chin; Galam, Dwight L A; Ghosh, Sujoy; Nguyen, Long N; Barathi, Veluchamy A; Yeo, Sia W; Luu, Chi D; Wenk, Markus R; Silver, David L

    2016-05-13

    Eye photoreceptor membrane discs in outer rod segments are highly enriched in the visual pigment rhodopsin and the ω-3 fatty acid docosahexaenoic acid (DHA). The eye acquires DHA from blood, but transporters for DHA uptake across the blood-retinal barrier or retinal pigment epithelium have not been identified. Mfsd2a is a newly described sodium-dependent lysophosphatidylcholine (LPC) symporter expressed at the blood-brain barrier that transports LPCs containing DHA and other long-chain fatty acids. LPC transport via Mfsd2a has been shown to be necessary for human brain growth. Here we demonstrate that Mfsd2a is highly expressed in retinal pigment epithelium in embryonic eye, before the development of photoreceptors, and is the primary site of Mfsd2a expression in the eye. Eyes from whole body Mfsd2a-deficient (KO) mice, but not endothelium-specific Mfsd2a-deficient mice, were DHA-deficient and had significantly reduced LPC/DHA transport in vivo Fluorescein angiography indicated normal blood-retinal barrier function. Histological and electron microscopic analysis indicated that Mfsd2a KO mice exhibited a specific reduction in outer rod segment length, disorganized outer rod segment discs, and mislocalization of and reduction in rhodopsin early in postnatal development without loss of photoreceptors. Minor photoreceptor cell loss occurred in adult Mfsd2a KO mice, but electroretinography indicated visual function was normal. The developing eyes of Mfsd2a KO mice had activated microglia and up-regulation of lipogenic and cholesterogenic genes, likely adaptations to loss of LPC transport. These findings identify LPC transport via Mfsd2a as an important pathway for DHA uptake in eye and for development of photoreceptor membrane discs.

  20. Listeria monocytogenes encephalitis mimicking Herpes Simplex virus encephalitis: the differential diagnostic importance of cerebrospinal fluid lactic acid levels.

    PubMed

    Cunha, Burke A; Fatehpuria, Ritu; Eisenstein, Lawrence E

    2007-01-01

    Listeria monocytogenes is a common cause of bacterial meningitis in elderly patients and in those with impaired cellular immunity. The most common central nervous system infection caused by L. monocytogenes is acute bacterial meningitis; meningoencephalitis is uncommon and encephalitis is rare. Early diagnosis of L. monocytogenes meningitis is difficult because only 50% of cerebrospinal fluid (CSF) Gram stains are negative. L. monocytogenes is one of the few central nervous system pathogens associated with red blood cells in the CSF. When L. monocytogenes presents as encephalitis with red blood cells in the CSF, the clinical presentation mimics most closely herpes simplex virus (HSV)-1 encephalitis. Because the therapies for L. monocytogenes and HSV-1 are different, early diagnostic differentiation is clinically important. The CSF lactic acid is the best way to rapidly differentiate between these two entities; the CSF lactic acid level is elevated in L. monocytogenes but is not elevated in HSV-1 encephalitis. The case presented is an elderly man with chronic lymphocytic leukemia who presented with encephalitis. Advanced age and chronic lymphocytic leukemia predispose him to a wide variety of pathogens, but the rapidity and severity of his clinical presentation made L. monocytogenes and HSV-1 encephalitis the most likely diagnostic possibilities. The CSF Gram stain was negative, but the elevated CSF lactic acid levels with encephalitis and red blood cells in the CSF indicated L. monocytogenes as the most likely pathogen. We present a case of L. monocytogenes encephalitis mimicking HSV-1 encephalitis. While receiving ampicillin therapy, the patient remained unresponsive for more than 1 week and then suddenly regained consciousness and recovered without neurologic sequelae.

  1. Importance of Solvation in Understanding the Chiroptical Spectra of Natural Products in Solution Phase: Garcinia Acid Dimethyl Ester

    PubMed Central

    Polavarapu, Prasad L.; Scalmani, Giovanni; Hawkins, Edward K.; Rizzo, Carmelo; Jeirath, Neha; Ibnusaud, Ibrahim; Habel, Deenamma; Nair, Divya Sadasivan; Haleema, Simimole

    2013-01-01

    The optical rotatory dispersion (ORD), electronic circular dichroism (ECD), and vibrational circular dichroism (VCD) spectra of (+)-garcinia acid dimethyl ester have been measured and analyzed by comparison with the corresponding spectra predicted by quantum chemical methods for (2S,3S)-garcinia acid dimethyl ester. For solution-phase calculations the recently developed continuous surface charge polarizable continuum model (PCM) has been used. It is found that gas-phase predictions and PCM predictions at the B3LYP/aug-cc-pVDZ level yield nearly mirror-image ECD spectra in the 190–250 nm region for the same absolute configuration and that gas-phase ECD predictions lead to incorrect absolute configuration. At the CAM-B3LYP/aug-cc-pVDZ level, however, gas-phase predictions and PCM predictions of ECD in the 190–250 nm region are not so different, but PCM predictions provide better agreement with the experimental observations. For carbonyl stretching vibrations, the vibrational band positions predicted at the B3LYP/aug-cc-pVDZ level in gas-phase calculations differ significantly from the corresponding experimentally observed band positions, and this discrepancy has also been corrected by the use of PCM. In addition, the solution-phase VCD predictions provided better agreement (with experimental VCD observations) than gas-phase VCD predictions. These observations underscore the importance of including solvent effects in quantum chemical calculations of chiroptical spectroscopic properties. PMID:21114277

  2. Identification of functionally important amino acid residues in the mitochondria targeting sequence of Hepatitis B virus X protein

    SciTech Connect

    Li, Sai Kam; Ho, Sai Fan; Tsui, Kwok Wing; Fung, Kwok Pui; Waye, M.Y. Mary

    2008-11-10

    Chronic hepatitis B virus (HBV) infection has been strongly associated with hepatocellular carcinoma (HCC) and the X protein (HBx) is thought to mediate the cellular changes associated with carcinogenesis. Recently, isolation of the hepatitis B virus integrants from HCC tissue by others have established the fact that the X gene is often truncated at its C-terminus. Expression of the GFP fusion proteins of HBx and its truncation mutants with a GFP tag in human liver cell-lines in this study revealed that the C-terminus of HBx is indispensable for its specific localization in the mitochondria. A crucial region of seven amino acids at the C-terminus has been mapped out in which the cysteine residue at position 115 serves as the most important residue for the subcellular localization. When cysteine 115 of HBx is mutated to alanine the mitochondria targeting property of HBx is abrogated.

  3. An amino acid substitution in the pyruvate dehydrogenase E1{alpha} gene, affecting mitochondrial import of the precursor protein

    SciTech Connect

    Takakubo, F.; Thorburn, D.R.; Dahl, H.H.M.

    1995-10-01

    A mutation in the mitochondrial targeting sequence was characterized in a male patient with X chromosome-linked pyruvate dehydrogenase E1{alpha} deficiency. The mutation was a base substitution of G by C at nucleotide 134 in the mitochondrial targeting sequence of the PDHA1 gene, resulting in an arginine-to-proline substitution at codon 10 (R10P). Pyruvate dehydrogenase activity in cultured skin fibroblasts was 28% of the control value, and immunoblot analysis revealed a decreased level of pyruvate dehydrogenase E1{alpha}immunoreactivity. Chimeric constructs in which the normal and mutant pyruvate dehydrogenase E1{alpha} targeting sequences were attached to the mitochondrial matrix protein ornithine transcarbamylase were synthesized in a cell free translation system, and mitochondrial import of normal and mutant proteins was compared in vitro. The results show that ornithine transcarbamylase targeted by the mutant pyruvate dehydrogenase E1{alpha} sequence was translocated into the mitochondrial matrix at a reduced rate, suggesting that defective import is responsible for the reduced pyruvate dehydrogenase level in mitochondria. The mutation was also present in an affected brother and the mildly affected mother. The clinical presentations of this X chromosome-linked disorder in affected family members are discussed. To our knowledge, this is the first report of an amino acid substitution in a mitochondrial targeting sequence resulting in a human genetic disease. 58 refs., 5 figs., 1 tab.

  4. In vivo and vitro studies on formation of bile acids in patients with Zellweger syndrome. Evidence that peroxisomes are of importance in the normal biosynthesis of both cholic and chenodeoxycholic acid.

    PubMed Central

    Kase, B F; Pedersen, J I; Strandvik, B; Björkhem, I

    1985-01-01

    The last step in bile acid formation involves conversion of 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-cholestanoic acid (THCA) into cholic acid and 3 alpha,7 alpha-dihydroxy-5 beta-cholestanoic acid (DHCA) into chenodeoxycholic acid. The peroxisomal fraction of rat and human liver has the highest capacity to catalyze these reactions. Infants with Zellweger syndrome lack liver peroxisomes, and accumulate 5 beta-cholestanoic acids in bile and serum. We recently showed that such an infant had reduced capacity to convert a cholic acid precursor, 5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol into cholic acid. 7 alpha-Hydroxy-4-cholesten-3-one is a common precursor for both cholic acid and chenodeoxycholic acid. Intravenous administration of [3H]7 alpha-hydroxy-4-cholesten-3-one to an infant with Zellweger syndrome led to a rapid incorporation of 3H into biliary THCA but only 10% of 3H was incorporated into cholic acid after 48 h. The incorporation of 3H into DHCA was only 25% of that into THCA and the incorporation into chenodeoxycholic acid approximately 50% of that in cholic acid. The conversion of intravenously administered [3H]THCA into cholic acid in another infant with Zellweger syndrome was only 7%. There was a slow conversion of THCA into 3 alpha,7 alpha,12 alpha-trihydroxy-5 beta-C29-dicarboxylic acid. The pool size of both cholic- and chenodeoxycholic acid was markedly reduced. Preparations of liver from two patients with Zellweger syndrome had no capacity to catalyze conversion of THCA into cholic acid. There was, however, a small conversion of DHCA into chenodeoxycholic acid and into THCA. It is concluded that liver peroxisomes are important both for the conversion of THCA into cholic acid and DHCA into chenodeoxycholic acid. PMID:4077985

  5. [Folic acid intake in daily food rations of 20-25 years old women from Wroclaw and assessment of knowledge about its importance for health].

    PubMed

    Wyka, Joanna; Mikołajczak, Jolanta

    2007-01-01

    The mean folic acid content in the diets of 50 young women from Wroclaw was 282 mcg and complied in 70.5% of recommended intake in prophylactic of neural tube defects. Only 8% of women used peri-conceptional folate supplementation every day. In the examined group low knowledge about importance of folic acid in health was noticed. Educational interventions are required to inform women at childbearing age of the benefits resulting from supplementation of diet with folic acid.

  6. Tomato Glutamate Decarboxylase Genes SlGAD2 and SlGAD3 Play Key Roles in Regulating γ-Aminobutyric Acid Levels in Tomato (Solanum lycopersicum).

    PubMed

    Takayama, Mariko; Koike, Satoshi; Kusano, Miyako; Matsukura, Chiaki; Saito, Kazuki; Ariizumi, Tohru; Ezura, Hiroshi

    2015-08-01

    Tomato (Solanum lycopersicum) can accumulate relatively high levels of γ-aminobutyric acid (GABA) during fruit development. However, the molecular mechanism underlying GABA accumulation and its physiological function in tomato fruits remain elusive. We previously identified three tomato genes (SlGAD1, SlGAD2 and SlGAD3) encoding glutamate decarboxylase (GAD), likely the key enzyme for GABA biosynthesis in tomato fruits. In this study, we generated transgenic tomato plants in which each SlGAD was suppressed and those in which all three SlGADs were simultaneously suppressed. A significant decrease in GABA levels, i.e. 50-81% compared with wild-type (WT) levels, was observed in mature green (MG) fruits of the SlGAD2-suppressed lines, while a more drastic reduction (up to <10% of WT levels) was observed in the SlGAD3- and triple SlGAD-suppressed lines. These findings suggest that both SlGAD2 and SlGAD3 expression are crucial for GABA biosynthesis in tomato fruits. The importance of SlGAD3 expression was also confirmed by generating transgenic tomato plants that over-expressed SlGAD3. The MG and red fruits of the over-expressing transgenic lines contained higher levels of GABA (2.7- to 5.2-fold) than those of the WT. We also determined that strong down-regulation of the SlGADs had little effect on overall plant growth, fruit development or primary fruit metabolism under normal growth conditions.

  7. Quantitative analysis of desorption and decomposition kinetics of formic acid on Cu(111): The importance of hydrogen bonding between adsorbed species

    SciTech Connect

    Shiozawa, Yuichiro; Koitaya, Takanori; Mukai, Kozo; Yoshimoto, Shinya; Yoshinobu, Jun

    2015-12-21

    Quantitative analysis of desorption and decomposition kinetics of formic acid (HCOOH) on Cu(111) was performed by temperature programmed desorption (TPD), X-ray photoelectron spectroscopy, and time-resolved infrared reflection absorption spectroscopy. The activation energy for desorption is estimated to be 53–75 kJ/mol by the threshold TPD method as a function of coverage. Vibrational spectra of the first layer HCOOH at 155.3 K show that adsorbed molecules form a polymeric structure via the hydrogen bonding network. Adsorbed HCOOH molecules are dissociated gradually into monodentate formate species. The activation energy for the dissociation into monodentate formate species is estimated to be 65.0 kJ/mol at a submonolayer coverage (0.26 molecules/surface Cu atom). The hydrogen bonding between adsorbed HCOOH species plays an important role in the stabilization of HCOOH on Cu(111). The monodentate formate species are stabilized at higher coverages, because of the lack of vacant sites for the bidentate formation.

  8. Site-Directed Mutagenesis of HgcA and HgcB Reveals Amino Acid Residues Important for Mercury Methylation

    PubMed Central

    Smith, Steven D.; Bridou, Romain; Johs, Alexander; Parks, Jerry M.; Elias, Dwayne A.; Hurt, Richard A.; Brown, Steven D.; Podar, Mircea

    2015-01-01

    Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential for mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative “cap helix” region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. This study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin. PMID:25724962

  9. Site-Directed Mutagenesis of HgcA and HgcB Reveals Amino Acid Residues Important for Mercury Methylation

    DOE PAGES

    Smith, Steven D.; Bridou, Romain; Johs, Alexander; ...

    2015-02-27

    Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential formore » mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative “cap helix” region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. Ultimately, this study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin.« less

  10. Ammonia-oxidizing archaea have more important role than ammonia-oxidizing bacteria in ammonia oxidation of strongly acidic soils.

    PubMed

    Zhang, Li-Mei; Hu, Hang-Wei; Shen, Ju-Pei; He, Ji-Zheng

    2012-05-01

    Increasing evidence demonstrated the involvement of ammonia-oxidizing archaea (AOA) in the global nitrogen cycle, but the relative contributions of AOA and ammonia-oxidizing bacteria (AOB) to ammonia oxidation are still in debate. Previous studies suggest that AOA would be more adapted to ammonia-limited oligotrophic conditions, which seems to be favored by protonation of ammonia, turning into ammonium in low-pH environments. Here, we investigated the autotrophic nitrification activity of AOA and AOB in five strongly acidic soils (pH<4.50) during microcosm incubation for 30 days. Significantly positive correlations between nitrate concentration and amoA gene abundance of AOA, but not of AOB, were observed during the active nitrification. (13)CO(2)-DNA-stable isotope probing results showed significant assimilation of (13)C-labeled carbon source into the amoA gene of AOA, but not of AOB, in one of the selected soil samples. High levels of thaumarchaeal amoA gene abundance were observed during the active nitrification, coupled with increasing intensity of two denaturing gradient gel electrophoresis bands for specific thaumarchaeal community. Addition of the nitrification inhibitor dicyandiamide (DCD) completely inhibited the nitrification activity and CO(2) fixation by AOA, accompanied by decreasing thaumarchaeal amoA gene abundance. Bacterial amoA gene abundance decreased in all microcosms irrespective of DCD addition, and mostly showed no correlation with nitrate concentrations. Phylogenetic analysis of thaumarchaeal amoA gene and 16S rRNA gene revealed active (13)CO(2)-labeled AOA belonged to groups 1.1a-associated and 1.1b. Taken together, these results provided strong evidence that AOA have a more important role than AOB in autotrophic ammonia oxidation in strongly acidic soils.

  11. Site-Directed Mutagenesis of HgcA and HgcB Reveals Amino Acid Residues Important for Mercury Methylation

    SciTech Connect

    Smith, Steven D.; Bridou, Romain; Johs, Alexander; Parks, Jerry M.; Elias, Dwayne A.; Hurt, Richard A.; Brown, Steven D.; Podar, Mircea; Wall, Judy D.

    2015-02-27

    Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential for mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative “cap helix” region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. Ultimately, this study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin.

  12. The Values of Outdoor Play

    ERIC Educational Resources Information Center

    Elkind, David

    2006-01-01

    This article describes outdoor play as a solid foundation and a central vehicle of knowledge about the real world. Outdoor play is important to all age levels, but particularly in early childhood and the elementary years. Children's outdoor play is not a luxury. It is critical in children's ability to learn about the world, others, and themselves.…

  13. The transmembrane tyrosines Y56, Y91 and Y167 play important roles in determining the affinity and transport rate of the rabbit proton-coupled peptide transporter PepT1.

    PubMed

    Pieri, Myrtani; Gan, Christine; Bailey, Patrick; Meredith, David

    2009-11-01

    The mammalian proton-coupled peptide transporter PepT1 is widely accepted as the major route of uptake for dietary nitrogen, as well as being responsible for the oral absorption of a number of classes of drugs, including beta-lactam antibiotics and angiotensin-converting enzyme (ACE) inhibitors. Using site-directed mutagenesis and zero-trans transport assays, we investigated the role of conserved tyrosines in the transmembrane domains (TMDs) of rabbit PepT1 as predicted by hydropathy plots. All the individual TMD tyrosines were substituted with phenylalanine and shown to retain the ability to traffic to the plasma membrane of Xenopus laevis oocytes. These single substitutions of TMD tyrosines by phenylalanine residues did not affect the proton dependence of peptide uptake, with all retaining wild-type PepT1-like pH dependence. Individual mutations of four of the nine TMD residue tyrosines (Y64, Y287, Y345 and Y587) were without measurable effect on PepT1 function, whereas the other five (Y12, Y56, Y91, Y167 and Y345) were shown to result in altered transport function compared to the wild-type PepT1. Intriguingly, the affinity of Y56F-PepT1 was found to be dramatically increased (approximately 100-fold) in comparison to that of the wild-type rabbit PepT1. Y91 mutations also affected the substrate affinity of the transporter, which increased in line with the hydrophilicity of the substituted amino acid (F>Y>Q>R). Y167 was demonstrated to play a pivotal role in rabbit PepT1 function since Y167F, Y167R and Y167Q demonstrated very little transport function. These results are discussed with regard to a proposed mechanism for PepT1 substrate binding.

  14. Fatty acid transport by vectorial acylation in mammals: roles played by different isoforms of rat long-chain acyl-CoA synthetases.

    PubMed

    Tong, Fumin; Black, Paul N; Coleman, Rosalind A; DiRusso, Concetta C

    2006-03-01

    Mammals express multiple isoforms of acyl-CoA synthetase (ACSL1 and ACSL3-6) in various tissues. These enzymes are essential for fatty acid metabolism providing activated intermediates for complex lipid synthesis, protein modification, and beta-oxidation. Yeast in contrast express four major ACSLs, which have well-defined functions. Two, Faa1p and Faa4p, are specifically required for fatty acid transport by vectorial acylation. Four ACSLs from the rat were expressed in a yeast faa1delta faa4delta strain and their roles in fatty acid transport and trafficking characterized. All four restored ACS activity yet varied in substrate preference. ACSL1, 4, and 6 were able to rescue fatty acid transport activity and triglyceride synthesis. ACSL5, however, was unable to facilitate fatty acid transport despite conferring robust oleoyl-CoA synthetase activity. This is the first study evaluating the role of the mammalian ACSLs in fatty acid transport and supports a role for ACSL1, 4, and 6 in transport by vectorial acylation.

  15. A novel small acid soluble protein variant is important for spore resistance of most Clostridium perfringens food poisoning isolates.

    PubMed

    Li, Jihong; McClane, Bruce A

    2008-05-02

    Clostridium perfringens is a major cause of food poisoning (FP) in developed countries. C. perfringens isolates usually induce the gastrointestinal symptoms of this FP by producing an enterotoxin that is encoded by a chromosomal (cpe) gene. Those typical FP strains also produce spores that are extremely resistant to food preservation approaches such as heating and chemical preservatives. This resistance favors their survival and subsequent germination in improperly cooked, prepared, or stored foods. The current study identified a novel alpha/beta-type small acid soluble protein, now named Ssp4, and showed that sporulating cultures of FP isolates producing resistant spores consistently express a variant Ssp4 with an Asp substitution at residue 36. In contrast, Gly was detected at Ssp4 residue 36 in C. perfringens strains producing sensitive spores. Studies with isogenic mutants and complementing strains demonstrated the importance of the Asp 36 Ssp4 variant for the exceptional heat and sodium nitrite resistance of spores made by most FP strains carrying a chromosomal cpe gene. Electrophoretic mobility shift assays and DNA binding studies showed that Ssp4 variants with an Asp at residue 36 bind more efficiently and tightly to DNA than do Ssp4 variants with Gly at residue 36. Besides suggesting one possible mechanistic explanation for the highly resistant spore phenotype of most FP strains carrying a chromosomal cpe gene, these findings may facilitate eventual development of targeted strategies to increase killing of the resistant spores in foods. They also provide the first indication that SASP variants can be important contributors to intra-species (and perhaps inter-species) variations in bacterial spore resistance phenotypes. Finally, Ssp4 may contribute to spore resistance properties throughout the genus Clostridium since ssp4 genes also exist in the genomes of other clostridial species.

  16. Nucleic Acids Research Group (NRG): The Importance of DNA Extraction in Metagenomics: The Gatekeeper to Accurate Results!

    PubMed Central

    Carmical, R.; Nadella, V.; Herbert, Z.; Beckloff, N.; Chittur, S.; Rosato, C.; Perera, A.; Auer, H.; Robinson, M.; Tighe, S.; Holbrook, Jennifer

    2013-01-01

    It is well recognized that the field of metagenomics is becoming a critical tool for studying previously unobtainable population dynamics at both an identification of species level and a functional or transcriptional level. Because the power to resolve microbial information is so important for identifying the components in an mixed sample, metagenomics can be used to study nearly any possible environment or system including clinical, environmental, and industrial, to name a few. Clinically, it may be used to determine sub-populations colonizing regions of the body or determining a rare infection to assist in treatment strategies. Environmentally it may be used to identify microbial populations within a soil, water or air sample, or within a bioreactor to characterize a population- based functional process. The possibilities are endless. However, the accuracy of a metagenomics dataset relies on three important “gatekeepers” including 1) The ability to effectively extract all DNA or RNA from every cell within a sample, 2) The reliability of the methods used for deep or high-throughput sequencing, and 3) The software used to analyze the data. Since DNA extraction is the first step in the technical process of metagenomics, the Nucleic Acid Research Group (NARG) conducted a study to evaluate extraction methods using a synthetic microbial sample. The synthetic microbial sample was prepared from 10 known bacteria at specific concentrations and ranging in diversity. Samples were extracted in duplicate using various popular kit based methods as well as several homebrew protocols then analyzed by NextGen sequencing on an Illumina HiSeq. Results of the study include determining the percent recovery of those organisms by comparing to the known quantity in the original synthetic mix.

  17. Design and Exploration of Novel Boronic Acid Inhibitors Reveals Important Interactions with a Clavulanic Acid-Resistant Sulfhydryl-Variable (SHV) β-Lactamase

    PubMed Central

    Winkler, Marisa L.; Rodkey, Elizabeth A.; Taracila, Magdalena A.; Drawz, Sarah M.; Bethel, Christopher R.; Papp-Wallace, Krisztina M.; Smith, Kerri M.; Xu, Yan; Dwulit-Smith, Jeffrey R.; Romagnoli, Chiara; Caselli, Emilia; Prati, Fabio; van den Akker, Focco; Bonomo, Robert A.

    2014-01-01

    Inhibitor resistant (IR) class A β-lactamases pose a significant threat to many current antibiotic combinations. The K234R substitution in the SHV β-lactamase, from Klebsiella pneumoniae, results in resistance to ampicillin/clavulanate. After site-saturation mutagenesis of Lys-234 in SHV, microbiological and biochemical characterization of the resulting β-lactamases revealed that only –Arg conferred resistance to ampicillin/clavulanate. X-ray crystallography revealed two conformations of Arg-234 and Ser-130 in SHV K234R. The movement of Ser-130 is the principal cause of the observed clavulanate resistance. A panel of boronic acid inhibitors was designed and tested against SHV-1 and SHV K234R. A chiral ampicillin analogue was discovered to have a 2.4 ± 0.2 nM Ki for SHV K234R; the chiral ampicillin analogue formed a more complex hydrogen-bonding network in SHV K234R vs SHV-1. Consideration of the spatial position of Ser-130 and Lys-234 and this hydrogen-bonding network will be important in the design of novel antibiotics targeting IR β-lactamases. PMID:23252553

  18. Molecular characterization of a mutation affecting abscisic acid biosynthesis and consequently stomatal responses to humidity in an agriculturally important species

    PubMed Central

    McAdam, Scott A. M.; Sussmilch, Frances C.; Brodribb, Timothy J.; Ross, John J.

    2015-01-01

    Mutants deficient in the phytohormone abscisic acid (ABA) have been instrumental in determining not only the biosynthetic pathway for this hormone, but also its physiological role in land plants. The wilty mutant of Pisum sativum is one of the classical, well-studied ABA-deficient mutants; however, this mutant remains uncharacterized at a molecular level. Using a candidate gene approach, we show that the wilty mutation affects the xanthoxin dehydrogenase step in ABA biosynthesis. To date, this step has only been represented by mutants in the ABA2 gene of Arabidopsis thaliana. Functional ABA biosynthesis appears to be critical for normal stomatal responses to changes in humidity in angiosperms, with wilty mutant plants having no increase in foliar ABA levels in response to a doubling in vapour pressure deficit, and no closure of stomata. Phylogenetic analysis of the ABA2 gene family from diverse land plants indicates that an ABA-biosynthesis-specific short-chain dehydrogenase (ABA2) evolved in the earliest angiosperms. The relatively recent origin of specificity in this step has important implications for both the evolution of ABA biosynthesis and action in land plants. PMID:26216469

  19. The Importance of the Ionic Product for Water to Understand the Physiology of the Acid-Base Balance in Humans

    PubMed Central

    Adeva-Andany, María M.; Carneiro-Freire, Natalia; Donapetry-García, Cristóbal; Rañal-Muíño, Eva; López-Pereiro, Yosua

    2014-01-01

    Human plasma is an aqueous solution that has to abide by chemical rules such as the principle of electrical neutrality and the constancy of the ionic product for water. These rules define the acid-base balance in the human body. According to the electroneutrality principle, plasma has to be electrically neutral and the sum of its cations equals the sum of its anions. In addition, the ionic product for water has to be constant. Therefore, the plasma concentration of hydrogen ions depends on the plasma ionic composition. Variations in the concentration of plasma ions that alter the relative proportion of anions and cations predictably lead to a change in the plasma concentration of hydrogen ions by driving adaptive adjustments in water ionization that allow plasma electroneutrality while maintaining constant the ionic product for water. The accumulation of plasma anions out of proportion of cations induces an electrical imbalance compensated by a fall of hydroxide ions that brings about a rise in hydrogen ions (acidosis). By contrast, the deficiency of chloride relative to sodium generates plasma alkalosis by increasing hydroxide ions. The adjustment of plasma bicarbonate concentration to these changes is an important compensatory mechanism that protects plasma pH from severe deviations. PMID:24877130

  20. DNA-dependent protein kinase interacts functionally with the RNA polymerase II complex recruited at the human immunodeficiency virus (HIV) long terminal repeat and plays an important role in HIV gene expression.

    PubMed

    Tyagi, Shilpi; Ochem, Alex; Tyagi, Mudit

    2011-07-01

    DNA-dependent protein kinase (DNA-PK), a nuclear protein kinase that specifically requires association with DNA for its kinase activity, plays important roles in the regulation of different DNA transactions, including transcription, replication and DNA repair, as well as in the maintenance of telomeres. Due to its large size, DNA-PK is also known to facilitate the activities of other factors by providing the docking platform at their site of action. In this study, by running several chromatin immunoprecipitation assays, we demonstrate the parallel distribution of DNA-PK with RNA polymerase II (RNAP II) along the human immunodeficiency virus (HIV) provirus before and after activation with tumour necrosis factor alpha. The association between DNA-PK and RNAP II is also long-lasting, at least for up to 4 h (the duration analysed in this study). Knockdown of endogenous DNA-PK using specific small hairpin RNAs expressed from lentiviral vectors resulted in significant reduction in HIV gene expression and replication, demonstrating the importance of DNA-PK for HIV gene expression. Sequence analysis of the HIV-1 Tat protein revealed three potential target sites for phosphorylation by DNA-PK and, by using kinase assays, we confirmed that Tat is an effective substrate of DNA-PK. Through peptide mapping, we found that two of these three potential phosphorylation sites are recognized and phosphorylated by DNA-PK. Mutational studies on the DNA-PK target sites of Tat further demonstrated the functional significance of the Tat-DNA-PK interaction. Thus, overall our results clearly demonstrate the functional interaction between DNA-PK and RNAP II during HIV transcription.

  1. FoxP3+CD4+ regulatory T cells play an important role in acute HIV-1 infection in humanized Rag2−/−γC−/− mice in vivo

    PubMed Central

    Jiang, Qi; Zhang, Liguo; Wang, Rui; Jeffrey, Jerry; Washburn, Michael L.; Brouwer, Dedeke; Barbour, Selena; Kovalev, Grigoriy I.; Unutmaz, Derya

    2008-01-01

    The role of FoxP3+CD4+ regulatory T (Treg) cells in HIV-1 disease in vivo is poorly understood due to the lack of a robust model. We report here that CD4+FoxP3+ T cells are developed in all lymphoid organs in humanized Rag2−/−γC−/− (DKO-hu HSC) mice and they display both Treg phenotype and Treg function. These FoxP3+ Treg cells are preferentially infected and depleted by a pathogenic HIV-1 isolate in HIV-infected DKO-hu HSC mice; and depletion of Treg cells is correlated with induction of their apoptosis in vivo. When CD4+CD25+/hi Treg cells are depleted with the IL-2–toxin fusion protein (denileukin diftitox), HIV-1 infection is significantly impaired. This is demonstrated by reduced levels of productively infected cells in lymphoid organs and lower plasma viremia. Therefore, FoxP3+ Treg cells are productively infected and play an important role in acute HIV-1 infection in vivo. The DKO-hu HSC mouse will be a valuable model to study human Treg functions and their role in HIV-1 pathogenesis in vivo. PMID:18544681

  2. RBOH1-dependent H2O2 production and subsequent activation of MPK1/2 play an important role in acclimation-induced cross-tolerance in tomato

    PubMed Central

    Zhou, Yan-Hong; Yu, Jing-Quan

    2014-01-01

    H2O2 and mitogen-activated protein kinase (MAPK) cascades play important functions in plant stress responses, but their roles in acclimation response remain unclear. This study examined the functions of H2O2 and MPK1/2 in acclimation-induced cross-tolerance in tomato plants. Mild cold, paraquat, and drought as acclimation stimuli enhanced tolerance to more severe subsequent chilling, photooxidative, and drought stresses. Acclimation-induced cross-tolerance was associated with increased transcript levels of RBOH1 and stress- and defence-related genes, elevated apoplastic H2O2 accumulation, increased activity of NADPH oxidase and antioxidant enzymes, reduced glutathione redox state, and activation of MPK1/2 in tomato. Virus-induced gene silencing of RBOH1, MPK1, and MPK2 or MPK1/2 all compromised acclimation-induced cross-tolerance and associated stress responses. Taken together, these results strongly suggest that acclimation-induced cross-tolerance is largely attributed to RBOH1-dependent H2O2 production at the apoplast, which may subsequently activate MPK1/2 to induce stress responses. PMID:24323505

  3. RBOH1-dependent H2O2 production and subsequent activation of MPK1/2 play an important role in acclimation-induced cross-tolerance in tomato.

    PubMed

    Zhou, Jie; Xia, Xiao-Jian; Zhou, Yan-Hong; Shi, Kai; Chen, Zhixiang; Yu, Jing-Quan

    2014-02-01

    H2O2 and mitogen-activated protein kinase (MAPK) cascades play important functions in plant stress responses, but their roles in acclimation response remain unclear. This study examined the functions of H2O2 and MPK1/2 in acclimation-induced cross-tolerance in tomato plants. Mild cold, paraquat, and drought as acclimation stimuli enhanced tolerance to more severe subsequent chilling, photooxidative, and drought stresses. Acclimation-induced cross-tolerance was associated with increased transcript levels of RBOH1 and stress- and defence-related genes, elevated apoplastic H2O2 accumulation, increased activity of NADPH oxidase and antioxidant enzymes, reduced glutathione redox state, and activation of MPK1/2 in tomato. Virus-induced gene silencing of RBOH1, MPK1, and MPK2 or MPK1/2 all compromised acclimation-induced cross-tolerance and associated stress responses. Taken together, these results strongly suggest that acclimation-induced cross-tolerance is largely attributed to RBOH1-dependent H2O2 production at the apoplast, which may subsequently activate MPK1/2 to induce stress responses.

  4. Transcriptional profiling of canola developing embryo and identification of the important roles of BnDof5.6 in embryo development and fatty acids synthesis.

    PubMed

    Deng, Wei; Yan, Fang; Zhang, Xiaolan; Tang, Yuwei; Yuan, Yujin

    2015-08-01

    Canola is an important vegetable oil crop globally, and the understanding of the molecular mechanism underlying fatty acids biosynthesis during seed embryo development is an important research goal. Here we report the transcriptional profiling analysis of developing canola embryos using RNA-sequencing (RNA-Seq) method. RNA-Seq analysis generated 58,579,451 sequence reads aligned with 32,243 genes. It was found that a total of 55 differential expression genes (DEGs) encoding 28 enzymes function in carbon flow to fatty acids of storage TAG. Most of the DEGs encoding above enzymes showed similar expression pattern, indicating the DEGs are cooperatively involved in carbon flow into fatty acids. In addition, 41 DEGs associated with signal transductions, transport and metabolic processing of auxin, gibberellin, abscisic acid, cytokinin and salicylic acids were found in the RNA-Seq database, which indicates the important roles of the phytohormones in controlling embryo development and fatty acids synthesis. 122 DEGs encoding transcriptional factor family members were found in developing canola embryos. Furthermore, BnDOF5.6, a zinc finger transcriptional factor gene, found in RNA-Seq database was down-regulated in developing canola embryos. The transgenic plants displayed reduced embryo sizes, decreased fatty acids contents and altered seed fatty acids composition in canola. Down-regulated of BnDof5.6 also changed the expression levels of genes involved in fatty acids synthesis and desaturation. Our results indicate that BnDof5.6 is required for embryo development and fatty acids synthesis in canola. Overall this study presents new information on the global expression patterns of genes during embryo development and will expand our understanding of the complex molecular mechanism of carbon flow into fatty acids and embryo development in canola.

  5. High-level exogenous trans10, cis12 conjugated linoleic acid plays an anti-lipogenesis role in bovine mammary epithelial cells.

    PubMed

    Wang, Hongfang; Liu, Hongyun; Liu, Jianxin; Zhao, Ke; Wang, Chong; Yang, Weiren

    2014-07-01

    Primary bovine mammary epithelial cells (BMECs) were treated by 0, 37.5, 75, 112.5, 150 μmol/L trans10, cis12 conjugated linoleic acid (CLA) to evaluate the effects of different level trans10, cis12 CLA on lipogenesis in BMEC. Addition of 75-150 μmol/L trans10, cis12 CLA reduced significantly the triacylglycerol (TAG) content (P<0.05), but did not have inhibiting action on cell proliferation (P>0.05). Treatment with 150 μmol/L trans10, cis12 CLA for 48 h resulted in a 17.1% reduction (P<0.0001) of medium chain fatty acids (MCFA, C14acids (UFA) and a corresponding reduction of the mRNA abundance of acetyl coenzyme A (acetylCoA) carboxylase (ACC) (P=0.046), fatty acid synthase (FAS) (P=0.017) and stearoylCoA desaturase1 (SCD1) (P=0.002). Another finding was that trans10, cis12 CLA elevated expression of diacylglycerol acyltransferase2 (DGAT2) (P=0.020) and long chain acylCoA synthetases (ACSL) (P=0.032). In conclusion, higher trans10, cis12 CLA, not low trans10, cis12 CLA, inhibited milk fat synthesis and changed fatty acid composition by regulating the expression of FAS, ACC, SCD1, DGAT2 and ACSL.

  6. A novel Na(+)(K(+))/H(+) antiporter plays an important role in the growth of Acetobacter tropicalis SKU1100 at high temperatures via regulation of cation and pH homeostasis.

    PubMed

    Soemphol, Wichai; Tatsuno, Maki; Okada, Takahiro; Matsutani, Minenosuke; Kataoka, Naoya; Yakushi, Toshiharu; Matsushita, Kazunobu

    2015-10-10

    A gene encoding a putative Na(+)/H(+) antiporter was previously proposed to be involved in the thermotolerance mechanism of Acetobacter tropicalis SKU 1100. The results of this study show that disruption of this antiporter gene impaired growth at high temperatures with an external pH>6.5. The growth impairment at high temperatures was much more severe in the absence of Na(+) (with only the presence of K(+)); under these conditions, cells failed to grow even at 30°C and neutral to alkaline pH values, suggesting that this protein is also important for K(+) tolerance. Functional analysis with inside-out membrane vesicles from wild type and mutant strains indicated that the antiporter, At-NhaK2 operates as an alkali cation/proton antiporter for ions such as Na(+), K(+), Li(+), and Rb(+) at acidic to neutral pH values (6.5-7.5). The membrane vesicles were also shown to contain a distinct pH-dependent Na(+)(specific)/H(+) antiporter(s) that might function at alkaline pH values. In addition, phylogenetic analysis showed that At-NhaK2 is a novel type of Na(+)/H(+) antiporter belonging to a phylogenetically distinct new clade. These data demonstrate that At-NhaK2 functions as a Na(+)(K(+))/H(+) antiporter and is essential for K(+) and pH homeostasis during the growth of A. tropicalis SKU1100, especially at higher temperatures.

  7. SmMYC2a and SmMYC2b played similar but irreplaceable roles in regulating the biosynthesis of tanshinones and phenolic acids in Salvia miltiorrhiza

    PubMed Central

    Zhou, Yangyun; Sun, Wei; Chen, Junfeng; Tan, Hexin; Xiao, Ying; Li, Qing; Ji, Qian; Gao, Shouhong; Chen, Li; Chen, Shilin; Zhang, Lei; Chen, Wansheng

    2016-01-01

    Salvia miltiorrhiza Bunge, which contains tanshinones and phenolic acids as major classes of bioactive components, is one of the most widely used herbs in traditional Chinese medicine. Production of tanshinones and phenolic acids is enhanced by methyl jasmonate (MeJA). Transcription factor MYC2 is the switch of jasmontes signaling in plants. Here, we focused on two novel JA-inducible genes in S. miltiorrhiza, designated as SmMYC2a and SmMYC2b, which were localized in the nucleus. SmMYC2a and SmMYC2b were also discovered to interact with SmJAZ1 and SmJAZ2, implying that the two MYC2s might function as direct targets of JAZ proteins. Ectopic RNA interference (RNAi)-mediated knockdown experiments suggested that SmMYC2a/b affected multiple genes in tanshinone and phenolic acid biosynthetic pathway. Besides, the accumulation of tanshinones and phenolic acids was impaired by the loss of function in SmMYC2a/b. Meanwhile, SmMYC2a could bind with an E-box motif within SmHCT6 and SmCYP98A14 promoters, while SmMYC2b bound with an E-box motif within SmCYP98A14 promoter, through which the regulation of phenolic acid biosynthetic pathway might achieve. Together, these results suggest that SmMYC2a and SmMYC2b are JAZ-interacting transcription factors that positively regulate the biosynthesis of tanshinones and Sal B with similar but irreplaceable effects. PMID:26947390

  8. Enzymatic synthesis of 2'-modified nucleic acids: identification of important phosphate and ribose moieties in RNase P substrates.

    PubMed Central

    Conrad, F; Hanne, A; Gaur, R K; Krupp, G

    1995-01-01

    For the first time mosaic nucleic acids composed of 50% RNA and 50% DNA can be obtained as transcripts with T7 RNA polymerase. Two NTPs could be replaced simultaneously in a transcription reaction. This means more than 40 deoxynucleotides were inserted in one transcript. Previously, a maximum of two deoxynucleotides could be incorporated and 2'-O-methyl-NTPs were not substrates at all. We obtained reasonable transcript yields with a maximal level of 99% 2'-O-methyl-NTPs, and the products contained up to 58% 2'-O-methylnucleotides at more than 20 positions. Sequence-specific nucleotide incorporation was monitored by sequence ladders (partial alkali or iodine cleavage). No base misincorporations were detected with 100% dGTP, dCTP and dTTP, and with partial incorporation of dATP alpha S, 2'-O-methyl-GTP alpha S and 2'-O-methyl-CTP alpha S, whereas they were found with dATP, 2'-O-methyl-ATP alpha S and 2'-O-methyl-UTP alpha S. Quantitative data allow predetermined modification levels of partially modified transcripts. Highly modified transcripts can be used for structural and functional studies, in modification interference approaches and for in vitro evolution procedures. Modification interference studies revealed a small number of important phosphate and ribose moieties in RNase P substrates. The conversion of T7 RNA polymerase to a DNA polymerase extends the observation that there is no absolute distinction between RNA and DNA polymerases. Accordingly, an adapted concept of a primordial RNA world is presented. Images PMID:7541130

  9. Amino acids in the COOH-terminal region of the oxytocin receptor third intracellular domain are important for receptor function.

    PubMed

    Zhong, Miao; Parish, Bridgette; Murtazina, Dilyara A; Ku, Chun-Ying; Sanborn, Barbara M

    2007-04-01

    Previously, residue K6.30 in the COOH-terminal region of the third intracellular domain (3iC) of the oxytocin (OT) receptor (OTR) was identified as important for receptor function leading to phospholipase C activation in both OTR and the vasopressin V(2) receptor (V(2)R) chimera V(2)ROTR3iC. Substitution of either A6.28K or V6.30K in wild-type V(2)R did not recapitulate the increase in phosphatidylinositide (PI) turnover observed in V(2)ROTR3iC. Hence, the role of K6.30 may be context-specific. Deletion of two NH(2)-terminal OTR3iC segments in the V(2)ROTR3iC chimera did not diminish vasopressin-stimulated PI turnover, whereas deletion of RVSSVKL (residues 6.19-6.25) reduced receptor expression. Deletion of this sequence in wild-type OTR reduced expression by 50% without affecting affinity for [(3)H]OT. This OTR mutant was unable to activate PI turnover or extracellular signal-regulated kinase 1/2 phosphorylation. The effects of alanine substitution for individual residues in RVSSVKL indicated differential importance for OTR function. The R6.19A substitution lost high-affinity sites for [(3)H]OT and the ability to stimulate PI turnover. Affinity for [(3)H]OT and membrane expression was not affected by any other substitutions. OTR-V6.20A and OTR-K6.24A mutants functioned as well as wild-type OTR, whereas OTR S6.21A, S6.22A, and V6.23A mutants exhibited impaired abilities to activate PI turnover (20-40% of OTR), and the OTR-L6.25A mutant exhibited constitutive activity. In conclusion, specific amino acids in the RVSSVKL segment in the COOH-terminal region of the third intracellular domain of OTR influence the ability of OTR to activate G protein-mediated actions.

  10. Nonenzymatic synthesis of RNA and DNA oligomers on hexitol nucleic acid templates: the importance of the A structure

    NASA Technical Reports Server (NTRS)

    Kozlov, I. A.; Politis, P. K.; Van Aerschot, A.; Busson, R.; Herdewijn, P.; Orgel, L. E.; Bada, J. L. (Principal Investigator); Dolan, M. (Principal Investigator)

    1999-01-01

    Hexitol nucleic acid (HNA) is an analogue of DNA containing the standard nucleoside bases, but with a phosphorylated 1,5-anhydrohexitol backbone. HNA oligomers form duplexes having the nucleic acid A structure with complementary DNA or RNA oligomers. The HNA decacytidylate oligomer is an efficient template for the oligomerization of the 5'-phosphoroimidazolides of guanosine or deoxyguanosine. Comparison of the oligomerization efficiencies on HNA, RNA, and DNA decacytidylate templates under various conditions suggests strongly that only nucleic acid double helices with the A structure support efficient template-directed synthesis when 5'-phosphoroimidazolides of nucleosides are used as substrates.

  11. The role played by acid and basic centers in the activity of biomimetic catalysts of the catalase, peroxidase, and monooxidase reactions

    NASA Astrophysics Data System (ADS)

    Magerramov, A. M.; Nagieva, I. T.

    2010-11-01

    The acid-basic centers of heterogeneous carriers of catalase, peroxidase, and monooxigenase biomimetics, in particular, iron protoporphyrin deposited on active or neutral aluminum magnesium silicate, were studied. The catalytic activity of biomimetics was stabilized, which allowed us not only to synthesize fairly effective biomimetics but also to clarify certain details of the mechanism of their action and perform a comparative analysis of the functioning of biomimetics and the corresponding enzymes.

  12. Reactivity of chemical sensitizers toward amino acids in cellulo plays a role in the activation of the Nrf2-ARE pathway in human monocyte dendritic cells and the THP-1 cell line.

    PubMed

    Migdal, Camille; Botton, Jérémie; El Ali, Zeina; Azoury, Marie-Eliane; Guldemann, Joan; Giménez-Arnau, Elena; Lepoittevin, Jean-Pierre; Kerdine-Römer, Saadia; Pallardy, Marc

    2013-06-01

    Allergic contact dermatitis resulting from skin sensitization is an inflammatory skin disease linked to the use of chemicals termed haptens. Chemical reactivity is necessary for a chemical to be a sensitizer, allowing both covalent binding to proteins and maturation of dendritic cells (DCs) by mimicking "danger signals." The aim of this study was to evaluate how the reactivity of chemical sensitizers toward amino acids translates into a biological response using the activation of the nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway, which was assessed by the induction of three Nrf2 target genes (ho-1, nqo1, and il-8) and Nrf2 protein accumulation. Nrf2 activation is known to play a role in numerous detoxification mechanisms that could regulate danger signal outcomes in myeloid cells. Monocyte-derived DCs and THP-1 cells were exposed to (a) haptens with cysteine, lysine, or cysteine/lysine reactivity, (b) pro-/prehaptens, and (c) nonsensitizing molecules with reducing or oxidative properties (17 molecules in total). Chemicals were classified as "Nrf2 pathway activators" when at least two Nrf2 target genes associated with Nrf2 protein expression were induced. Results showed that most chemical sensitizers having cysteine and cysteine/lysine affinities were inducers of the Nrf2 pathway in both cell models, whereas lysine-reactive chemicals were less efficient. In THP-1 cells, the Nrf2 pathway was also activated by pro-/prehaptens. Regression analysis revealed that ho-1 and nqo1 expressions were found to be associated with chemical sensitizer reactivity to cysteine, providing evidence of the importance of chemical reactivity, as a part of danger signals, in DC biology.

  13. Negative Regulation of Abscisic Acid Signaling by the Fagus sylvatica FsPP2C1 Plays A Role in Seed Dormancy Regulation and Promotion of Seed Germination1

    PubMed Central

    González-García, Mary Paz; Rodríguez, Dolores; Nicolás, Carlos; Rodríguez, Pedro Luis; Nicolás, Gregorio; Lorenzo, Oscar

    2003-01-01

    FsPP2C1 was previously isolated from beech (Fagus sylvatica) seeds as a functional protein phosphatase type-2C (PP2C) with all the conserved features of these enzymes and high homology to ABI1, ABI2, and PP2CA, PP2Cs identified as negative regulators of ABA signaling. The expression of FsPP2C1 was induced upon abscisic acid (ABA) treatment and was also up-regulated during early weeks of stratification. Furthermore, this gene was specifically expressed in ABA-treated seeds and was hardly detectable in vegetative tissues. In this report, to provide genetic evidence on FsPP2C1 function in seed dormancy and germination, we used an overexpression approach in Arabidopsis because transgenic work is not feasible in beech. Constitutive expression of FsPP2C1 under the cauliflower mosaic virus 35S promoter confers ABA insensitivity in Arabidopsis seeds and, consequently, a reduced degree of seed dormancy. Additionally, transgenic 35S:FsPP2C1 plants are able to germinate under unfavorable conditions, as inhibitory concentrations of mannitol, NaCl, or paclobutrazol. In vegetative tissues, Arabidopsis FsPP2C1 transgenic plants show ABA-resistant early root growth and diminished induction of the ABA-response genes RAB18 and KIN2, but no effect on stomatal closure regulation. Seed and vegetative phenotypes of Arabidopsis 35S:FsPP2C1 plants suggest that FsPP2C1 negatively regulates ABA signaling. The ABA inducibility of FsPP2C1 expression, together with the transcript accumulation mainly in seeds, suggest that it could play an important role modulating ABA signaling in beechnuts through a negative feedback loop. Finally, we suggest that negative regulation of ABA signaling by FsPP2C1 is a factor contributing to promote the transition from seed dormancy to germination during early weeks of stratification. PMID:12970481

  14. Health information impact on the relative importance of beef attributes including its enrichment with polyunsaturated fatty acids (omega-3 and conjugated linoleic acid).

    PubMed

    Kallas, Zein; Realini, Carolina E; Gil, José Maria

    2014-08-01

    This paper uses Choice Experiments (CE) to investigate Spanish consumers' preferences towards beef meat enriched with polyunsaturated fatty acids (omega-3 and conjugated linoleic acid). Data were gathered from self-completed questionnaires in a controlled environment with two different samples (320 and 322 consumers) differentiated by the information received. The surveys were carried out in three main Spanish cities (Barcelona, Zaragoza and Pamplona), representing the average consumer. A variation of the "Dual Response Choice Experiments" (DRCE) design was used due to its ability to emphasize the purchase context. Results showed that consumers who received information attach higher preference for enriched meat with polyunsaturated fatty acids. The utility associated with the higher content of fat increase for informed consumers, showing a substitute effect. Informed consumers are willing to accept meat with a higher amount of visible fat if it is enriched with beneficial fatty acids.

  15. Type II Diacylglycerol Acyltransferase from Claviceps purpurea with Ricinoleic Acid, a Hydroxyl Fatty Acid of Industrial Importance, as Preferred Substrate ▿

    PubMed Central

    Mavraganis, Ioannis; Meesapyodsuk, Dauenpen; Vrinten, Patricia; Smith, Mark; Qiu, Xiao

    2010-01-01

    Claviceps purpurea, the fungal pathogen that causes the cereal disease ergot, produces glycerides that contain high levels of ricinoleic acid [(R)-12-hydroxyoctadec-cis-9-enoic acid] in its sclerotia. Recently, a fatty acid hydroxylase (C. purpurea FAH [CpFAH]) involved in the biosynthesis of ricinoleic acid was identified from this fungus (D. Meesapyodsuk and X. Qiu, Plant Physiol. 147:1325-1333, 2008). Here, we describe the cloning and biochemical characterization of a C. purpurea type II diacylglycerol acyltransferase (CpDGAT2) involved in the assembly of ricinoleic acid into triglycerides. The CpDGAT2 gene was cloned by degenerate RT-PCR (reverse transcription-PCR). The expression of this gene restored the in vivo synthesis of triacylglycerol (TAG) in the quadruple mutant strain Saccharomyces cerevisiae H1246, in which all four TAG biosynthesis genes (DGA1, LRO1, ARE1, and ARE2) are disrupted. In vitro enzymatic assays using microsomal preparations from the transformed yeast strain indicated that CpDGAT2 prefers ricinoleic acid as an acyl donor over linoleic acid, oleic acid, or linolenic acid, and it prefers 1,2-dioleoyl-sn-glycerol over 1,2-dipalmitoyl-sn-glycerol as an acyl acceptor. The coexpression of CpFAH with CpDGAT2 in yeast resulted in an increased accumulation of ricinoleic acid compared to the coexpression of CpFAH with the native yeast DGAT2 (S. cerevisiae DGA1 [ScDGA1]) or the expression of CpFAH alone. Northern blot analysis indicated that CpFAH is expressed solely in sclerotium cells, with no transcripts of this gene being detected in mycelium or conidial cells. CpDGAT2 was more widely expressed among the cell types examined, although expression was low in conidiospores. The high expression of CpDGAT2 and CpFAH in sclerotium cells, where high levels of ricinoleate glycerides accumulate, provided further evidence supporting the roles of CpDGAT2 and CpFAH as key enzymes for the synthesis and assembly of ricinoleic acid in C. purpurea. PMID

  16. Play Therapy: A Review

    ERIC Educational Resources Information Center

    Porter, Maggie L.; Hernandez-Reif, Maria; Jessee, Peggy

    2009-01-01

    This article discusses the current issues in play therapy and its implications for play therapists. A brief history of play therapy is provided along with the current play therapy approaches and techniques. This article also touches on current issues or problems that play therapists may face, such as interpreting children's play, implementing…

  17. Playing tricks to ions

    NASA Astrophysics Data System (ADS)

    Leibfried, Dietrich

    2017-01-01

    Ted Hänsch's career is defined by breaking new ground in experimental physics. Curiosity, vivid imagination, deep understanding, patience and tenacity are part of the winning formula, but perhaps an equally important ingredient may be Ted's favorite past-time of exploring new tricks in his "Spiellabor" (play-lab), that often resurfaced as key ingredients in rather serious experiments later. On the occasion of Ted's 75th birthday, a few past and potential future experiments with trapped ions are playfully surveyed here. Some of these tricks are already part of the trade, some are currently emerging and a few are mostly speculation today. Maybe some of the latter will be realized and even prove useful in the future.

  18. Differences in alpha 2u-globulins increased in male rat kidneys following treatment with several alpha 2u-globulin accumulating agents: cystein protease(s) play(s) an important role in production of kidney-type-alpha 2u-globulin.

    PubMed

    Saito, K; Kaneko, H; Isobe, N; Nakatsuka, I; Yoshitake, A; Yamada, H

    1992-11-30

    Effects of alpha 2u-globulin accumulating agents on alpha 2u-globulins in rat kidneys were examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting analysis. Treatment of male animals with decalin (150 mg/kg), 2,2,4-trimethylpentane (50 mg/kg), isophorone (150 mg/kg), d-limonene (150 mg/kg) or 1,4-dichlorobenzene (150 mg/kg) by gavage for 14 consecutive days in each case resulted in a marked intensification of a protein band corresponding to kidney-type-alpha 2u-globulin, with a molecular mass calculated to be approximately 16 kDa. However, intraperitoneal treatment with leupeptin and E-64 (two times 0.07 mmol/kg, for each), well known cystein protease inhibitors, while only slightly increasing this kidney-type-alpha 2u-globulin band, caused the intensification of a approximately 19-kDa molecular mass protein band which was revealed to be a native-type-alpha 2u-globulin by SDS-PAGE and immunoblotting. These results indicated that at least two types of alpha 2u-globulin can be increased in male rat kidney by chemical treatment. Moreover, cystein protease(s) appear(s) to play an important role in the degradation of alpha 2u-globulin and particularly in the conversion of native-type-alpha 2u-globulin to kidney-type-alpha 2u-globulin in rat kidneys.

  19. Proteomic Analysis Revealed the Important Role of Vimentin in Human Cervical Carcinoma HeLa Cells Treated With Gambogic Acid*

    PubMed Central

    Yue, Qingxi; Feng, Lixing; Cao, Biyin; Liu, Miao; Zhang, Dongmei; Wu, Wanying; Jiang, Baohong; Yang, Min; Liu, Xuan; Guo, Dean

    2016-01-01

    Gambogic acid (GA) is an anticancer agent in phase IIb clinical trial in China. In HeLa cells, GA inhibited cell proliferation, induced cell cycle arrest at G2/M phase and apoptosis, as showed by results of MTT assay and flow cytometric analysis. Possible target-related proteins of GA were searched using comparative proteomic analysis (2-DE) and nine proteins at early (3 h) stage together with nine proteins at late (24 h) stage were found. Vimentin was the only target-related protein found at both early and late stage. Results of both 2-DE analysis and Western blotting assay suggested cleavage of vimentin induced by GA. MS/MS analysis of cleaved vimentin peptides indicated possible cleavage sites of vimentin at or near ser51 and glu425. Results of targeted proteomic analysis showed that GA induced change in phosphorylation state of the vimentin head domain (aa51–64). Caspase inhibitors could not abrogate GA-induced cleavage of vimentin. Over-expression of vimentin ameliorated cytotoxicity of GA in HeLa cells. The GA-activated signal transduction, from p38 MAPK, heat shock protein 27 (HSP27), vimentin, dysfunction of cytoskeleton, to cell death, was predicted and then confirmed. Results of animal study showed that GA treatment inhibited tumor growth in HeLa tumor-bearing mice and cleavage of vimentin could be observed in tumor xenografts of GA-treated animals. Results of immunohistochemical staining also showed down-regulated vimentin level in tumor xenografts of GA-treated animals. Furthermore, compared with cytotoxicity of GA in HeLa cells, cytotoxicity of GA in MCF-7 cells with low level of vimentin was weaker whereas cytotoxicity of GA in MG-63 cells with high level of vimentin was stronger. These results indicated the important role of vimentin in the cytotoxicity of GA. The effects of GA on vimentin and other epithelial-to-mesenchymal transition (EMT) markers provided suggestion for better usage of GA in clinic. PMID:26499837

  20. Proteomic Analysis Revealed the Important Role of Vimentin in Human Cervical Carcinoma HeLa Cells Treated With Gambogic Acid.

    PubMed

    Yue, Qingxi; Feng, Lixing; Cao, Biyin; Liu, Miao; Zhang, Dongmei; Wu, Wanying; Jiang, Baohong; Yang, Min; Liu, Xuan; Guo, Dean

    2016-01-01

    Gambogic acid (GA) is an anticancer agent in phase IIb clinical trial in China. In HeLa cells, GA inhibited cell proliferation, induced cell cycle arrest at G2/M phase and apoptosis, as showed by results of MTT assay and flow cytometric analysis. Possible target-related proteins of GA were searched using comparative proteomic analysis (2-DE) and nine proteins at early (3 h) stage together with nine proteins at late (24 h) stage were found. Vimentin was the only target-related protein found at both early and late stage. Results of both 2-DE analysis and Western blotting assay suggested cleavage of vimentin induced by GA. MS/MS analysis of cleaved vimentin peptides indicated possible cleavage sites of vimentin at or near ser51 and glu425. Results of targeted proteomic analysis showed that GA induced change in phosphorylation state of the vimentin head domain (aa51-64). Caspase inhibitors could not abrogate GA-induced cleavage of vimentin. Over-expression of vimentin ameliorated cytotoxicity of GA in HeLa cells. The GA-activated signal transduction, from p38 MAPK, heat shock protein 27 (HSP27), vimentin, dysfunction of cytoskeleton, to cell death, was predicted and then confirmed. Results of animal study showed that GA treatment inhibited tumor growth in HeLa tumor-bearing mice and cleavage of vimentin could be observed in tumor xenografts of GA-treated animals. Results of immunohistochemical staining also showed down-regulated vimentin level in tumor xenografts of GA-treated animals. Furthermore, compared with cytotoxicity of GA in HeLa cells, cytotoxicity of GA in MCF-7 cells with low level of vimentin was weaker whereas cytotoxicity of GA in MG-63 cells with high level of vimentin was stronger. These results indicated the important role of vimentin in the cytotoxicity of GA. The effects of GA on vimentin and other epithelial-to-mesenchymal transition (EMT) markers provided suggestion for better usage of GA in clinic.

  1. Perfluoroalkyl acids and their precursors in Swedish food: The relative importance of direct and indirect dietary exposure.

    PubMed

    Gebbink, Wouter A; Glynn, Anders; Darnerud, Per Ola; Berger, Urs

    2015-03-01

    We analyzed food market basket samples obtained in Sweden from 1999, 2005, and 2010 for perfluoroalkyl acids (PFAAs) and a range of precursor compounds. Perfluorooctane sulfonic acid (PFOS) precursors were detected in all food year pools with the highest concentrations in 1999. Six polyfluoroalkyl phosphate diesters (diPAPs, 4:2/6:2, 6:2/6:2, 6:2/8:2, 8:2/8:2, 6:2/10:2, and 10:2/10:2) were detected in the year pools with the highest ∑diPAP concentrations in 1999 and 2005. All precursors were predominantly found in meat, fish, and/or eggs based on analysis of individual food groups from 1999. Based on year pools, PFOS precursors contributed between 4 and 1% as an indirect source to total dietary PFOS intakes between 1999 and 2010. Perfluorohexanoic acid (PFHxA) exposure originated entirely from diPAPs, whereas for perfluorooctanoic acid (PFOA) and perfluorodecanoic acid (PFDA), diPAPs contributed between 1 and 19% to total exposure. The lowest precursor contributions were generally seen in food samples from 2010.

  2. Increased long chain acyl-Coa synthetase activity and fatty acid import is linked to membrane synthesis for development of picornavirus replication organelles.

    PubMed

    Nchoutmboube, Jules A; Viktorova, Ekaterina G; Scott, Alison J; Ford, Lauren A; Pei, Zhengtong; Watkins, Paul A; Ernst, Robert K; Belov, George A

    2013-01-01

    All positive strand (+RNA) viruses of eukaryotes replicate their genomes in association with membranes. The mechanisms of membrane remodeling in infected cells represent attractive targets for designing future therapeutics, but our understanding of this process is very limited. Elements of autophagy and/or the secretory pathway were proposed to be hijacked for building of picornavirus replication organelles. However, even closely related viruses differ significantly in their requirements for components of these pathways. We demonstrate here that infection with diverse picornaviruses rapidly activates import of long chain fatty acids. While in non-infected cells the imported fatty acids are channeled to lipid droplets, in infected cells the synthesis of neutral lipids is shut down and the fatty acids are utilized in highly up-regulated phosphatidylcholine synthesis. Thus the replication organelles are likely built from de novo synthesized membrane material, rather than from the remodeled pre-existing membranes. We show that activation of fatty acid import is linked to the up-regulation of cellular long chain acyl-CoA synthetase activity and identify the long chain acyl-CoA syntheatse3 (Acsl3) as a novel host factor required for polio replication. Poliovirus protein 2A is required to trigger the activation of import of fatty acids independent of its protease activity. Shift in fatty acid import preferences by infected cells results in synthesis of phosphatidylcholines different from those in uninfected cells, arguing that the viral replication organelles possess unique properties compared to the pre-existing membranes. Our data show how poliovirus can change the overall cellular membrane homeostasis by targeting one critical process. They explain earlier observations of increased phospholipid synthesis in infected cells and suggest a simple model of the structural development of the membranous scaffold of replication complexes of picorna-like viruses, that may be

  3. A Place for Block Play.

    ERIC Educational Resources Information Center

    Moore, Gary T.

    1997-01-01

    Discusses the importance of block play--including its contributions to perceptual, fine motor, and cognitive development--and components of a good preschool block play area. Recommends unit blocks complemented by stacking blocks, toys, beads, cubes, and Brio wooden toys. Makes recommendations for space, size, locations and connections to other…

  4. Engaging Families through Artful Play

    ERIC Educational Resources Information Center

    Brown, Robert

    2015-01-01

    This paper explores how aligned arts and play experiences can extend child and family engagement in a public outdoor space. The importance of outdoor play for children is strongly advocated and in response local governments provide playgrounds and recreational open spaces. To extend further the experiences afforded in such spaces some local…

  5. The Child's Right To Play.

    ERIC Educational Resources Information Center

    Guddemi, Marcy

    Several factors are eroding children's right to play. The first is continuing poverty throughout the world. This factor is evident in underdeveloped countries and the inner cities of industrialized countries. Changing cultural values are a second factor in developed societies where indifference toward the importance of play is prevalent. The many…

  6. Outdoor Play: Combating Sedentary Lifestyles

    ERIC Educational Resources Information Center

    Thigpen, Betsy

    2007-01-01

    Increasingly sedentary lifestyles are contributing to overweight and other health concerns as children spend less and less time outside engaged in active play. Outdoor play provides important opportunities to explore the natural world, interact with peers, engage in vigorous physical activity, and learn about our environment. However, outdoor…

  7. The Denial of Play.

    ERIC Educational Resources Information Center

    Sutton-Smith, Brian

    Well meaning parents and teachers often use children's play for the purposes of literacy and socialization. Yet, these attempts may deny play to children by subordinating play to some other concept. Evidence shows that even when parents play with their very young children they generally play games like shopping, cooking, and eating; whereas when…

  8. Children's Play and Television.

    ERIC Educational Resources Information Center

    Powell, Mark

    2001-01-01

    Discusses adverse effects of FCC deregulation of children's television programming on children's play behavior. Discusses the difference between play and imitation, the role of high quality dramatic play in healthy child development, the popularity of war play, and use of toys to increase dramatic play. Considers ways to help children gain control…

  9. Rice G-protein subunits qPE9-1 and RGB1 play distinct roles in abscisic acid responses and drought adaptation.

    PubMed

    Zhang, Dong-Ping; Zhou, Yong; Yin, Jian-Feng; Yan, Xue-Jiao; Lin, Sheng; Xu, Wei-Feng; Baluška, František; Wang, Yi-Ping; Xia, Yi-Ji; Liang, Guo-hua; Liang, Jian-Sheng

    2015-10-01

    Heterotrimeric GTP-binding protein (G-protein)-mediated abscisic acid (ABA) and drought-stress responses have been documented in numerous plant species. However, our understanding of the function of rice G-protein subunits in ABA signalling and drought tolerance is limited. In this study, the function of G-protein subunits in ABA response and drought resistance in rice plants was explored. It was found that the transcription level of qPE9-1 (rice Gγ subunit) gradually decreased with increasing ABA concentration and the lack of qPE9-1 showed an enhanced drought tolerance in rice plants. In contrast, mRNA levels of RGB1 (rice Gβ subunit) were significantly upregulated by ABA treatment and the lack of RGB1 led to reduced drought tolerance. Furthermore, the results suggested that qPE9-1 negatively regulates the ABA response by suppressing the expression of key transcription factors involved in ABA and stress responses, while RGB1 positively regulates ABA biosynthesis by upregulating NCED gene expression under both normal and drought stress conditions. Taken together, it is proposed that RGB1 is a positive regulator of the ABA response and drought adaption in rice plants, whereas qPE9-1 is modulated by RGB1 and functions as a negative regulator in the ABA-dependent drought-stress responses.

  10. Host-Derived Sialic Acids Are an Important Nutrient Source Required for Optimal Bacterial Fitness In Vivo

    PubMed Central

    McDonald, Nathan D.; Lubin, Jean-Bernard; Chowdhury, Nityananda

    2016-01-01

    ABSTRACT A major challenge facing bacterial intestinal pathogens is competition for nutrient sources with the host microbiota. Vibrio cholerae is an intestinal pathogen that causes cholera, which affects millions each year; however, our knowledge of its nutritional requirements in the intestinal milieu is limited. In this study, we demonstrated that V. cholerae can grow efficiently on intestinal mucus and its component sialic acids and that a tripartite ATP-independent periplasmic SiaPQM strain, transporter-deficient mutant NC1777, was attenuated for colonization using a streptomycin-pretreated adult mouse model. In in vivo competition assays, NC1777 was significantly outcompeted for up to 3 days postinfection. NC1777 was also significantly outcompeted in in vitro competition assays in M9 minimal medium supplemented with intestinal mucus, indicating that sialic acid uptake is essential for fitness. Phylogenetic analyses demonstrated that the ability to utilize sialic acid was distributed among 452 bacterial species from eight phyla. The majority of species belonged to four phyla, Actinobacteria (members of Actinobacillus, Corynebacterium, Mycoplasma, and Streptomyces), Bacteroidetes (mainly Bacteroides, Capnocytophaga, and Prevotella), Firmicutes (members of Streptococcus, Staphylococcus, Clostridium, and Lactobacillus), and Proteobacteria (including Escherichia, Shigella, Salmonella, Citrobacter, Haemophilus, Klebsiella, Pasteurella, Photobacterium, Vibrio, and Yersinia species), mostly commensals and/or pathogens. Overall, our data demonstrate that the ability to take up host-derived sugars and sialic acid specifically allows V. cholerae a competitive advantage in intestinal colonization and that this is a trait that is sporadic in its occurrence and phylogenetic distribution and ancestral in some genera but horizontally acquired in others. PMID:27073099

  11. Characterization and symbiotic importance of acidic extracellular polysaccharides of Rhizobium sp. strain GRH2 isolated from acacia nodules.

    PubMed Central

    Lopez-Lara, I M; Orgambide, G; Dazzo, F B; Olivares, J; Toro, N

    1993-01-01

    Rhizobium sp. wild-type strain GRH2 was originally isolated from root nodules of the leguminous tree Acacia cyanophylla and has a broad host range which includes herbaceous legumes, e.g., Trifolium spp. We examined the extracellular exopolysaccharides (EPSs) produced by strain GRH2 and found three independent glycosidic structures: a high-molecular-weight acidic heteropolysaccharide which is very similar to the acidic EPS produced by Rhizobium leguminosarum biovar trifolii ANU843, a low-molecular-weight native heterooligosaccharide resembling a dimer of the repeat unit of the high-molecular-weight EPS, and low-molecular-weight neutral beta (1,2)-glucans. A Tn5 insertion mutant derivative of GRH2 (exo-57) that fails to form acidic heteropolysaccharides was obtained. This Exo- mutant formed nitrogen-fixing nodules on Acacia plants but infected a smaller proportion of cells in the central zone of the nodules than did wild-type GRH2. In addition, the exo-57 mutant failed to nodulate several herbaceous legume hosts that are nodulated by wild-type strain GRH2. Images PMID:8491702

  12. Importance of ligand exchanges in Pd(II)-Brønsted acid cooperative catalytic approach to spirocyclic rings.

    PubMed

    Jindal, Garima; Sunoj, Raghavan B

    2014-11-12

    Increasing number of reports in the most recent literature convey the use of palladium and Brønsted acids as cooperative catalytic partners. However, the mechanistic understanding of several such cooperative catalytic reactions and the origin of cooperativity continue to remain limited. In transition metal catalysis, it is typically assumed that the native ligands, such as the acetates in palladium acetate, are retained throughout the catalytic cycle. Herein, we convey the significance of invoking ligand exchanges in transition metal catalysis by using the mechanism of a representative cooperative dual-catalytic reaction. Density functional theory (M06 and B3LYP) computations have been employed to decipher the mechanism of Pd(II)-Brønsted acid catalyzed migratory ring expansion reaction of an indenyl cyclobutanol to a spirocyclic indene bearing a quaternary carbon. The molecular role of water, benzoquinone and phosphoric acid has been probed by computing the energetics using several combinations of all these as ligands on palladium. Of the two key mechanistic possibilities examined, a Wacker-type pathway (involving a semipinacol ring expansion of cyclobutanol followed by a reductive elimination) is found to be energetically more preferred over an allylic pathway wherein the ring expansion in a Pd-π-allyl intermediate occurs subsequent to the initial allylic C-H activation. The Gibbs free energies of the transition states with the native palladium acetate are much higher than a Pd-bis-phosphate species generated through ligand exchanges.

  13. The C-terminal 50 Amino Acid Residues of Dengue NS3 Protein Are Important for NS3-NS5 Interaction and Viral Replication*

    PubMed Central

    Tay, Moon Y. F.; Saw, Wuan Geok; Zhao, Yongqian; Chan, Kitti W. K.; Singh, Daljit; Chong, Yuwen; Forwood, Jade K.; Ooi, Eng Eong; Grüber, Gerhard; Lescar, Julien; Luo, Dahai; Vasudevan, Subhash G.

    2015-01-01

    Dengue virus multifunctional proteins NS3 protease/helicase and NS5 methyltransferase/RNA-dependent RNA polymerase form part of the viral replication complex and are involved in viral RNA genome synthesis, methylation of the 5′-cap of viral genome, and polyprotein processing among other activities. Previous studies have shown that NS5 residue Lys-330 is required for interaction between NS3 and NS5. Here, we show by competitive NS3-NS5 interaction ELISA that the NS3 peptide spanning residues 566–585 disrupts NS3-NS5 interaction but not the null-peptide bearing the N570A mutation. Small angle x-ray scattering study on NS3(172–618) helicase and covalently linked NS3(172–618)-NS5(320–341) reveals a rigid and compact formation of the latter, indicating that peptide NS5(320–341) engages in specific and discrete interaction with NS3. Significantly, NS3:Asn-570 to alanine mutation introduced into an infectious DENV2 cDNA clone did not yield detectable virus by plaque assay even though intracellular double-stranded RNA was detected by immunofluorescence. Detection of increased negative-strand RNA synthesis by real time RT-PCR for the NS3:N570A mutant suggests that NS3-NS5 interaction plays an important role in the balanced synthesis of positive- and negative-strand RNA for robust viral replication. Dengue virus infection has become a global concern, and the lack of safe vaccines or antiviral treatments urgently needs to be addressed. NS3 and NS5 are highly conserved among the four serotypes, and the protein sequence around the pinpointed amino acids from the NS3 and NS5 regions are also conserved. The identification of the functionally essential interaction between the two proteins by biochemical and reverse genetics methods paves the way for rational drug design efforts to inhibit viral RNA synthesis. PMID:25488659

  14. Import of amber and ochre suppressor tRNAs into mammalian cells: A general approach to site-specific insertion of amino acid analogues into proteins

    PubMed Central

    Köhrer, Caroline; Xie, Liang; Kellerer, Susanne; Varshney, Umesh; RajBhandary, Uttam L.

    2001-01-01

    A general approach to site-specific insertion of amino acid analogues into proteins in vivo would be the import into cells of a suppressor tRNA aminoacylated with the analogue of choice. The analogue would be inserted at any site in the protein specified by a stop codon in the mRNA. The only requirement is that the suppressor tRNA must not be a substrate for any of the cellular aminoacyl–tRNA synthetases. Here, we describe conditions for the import of amber and ochre suppressor tRNAs derived from Escherichia coli initiator tRNA into mammalian COS1 cells, and we present evidence for their activity in the specific suppression of amber (UAG) and ochre (UAA) codons, respectively. We show that an aminoacylated amber suppressor tRNA (supF) derived from the E. coli tyrosine tRNA can be imported into COS1 cells and acts as a suppressor of amber codons, whereas the same suppressor tRNA imported without prior aminoacylation does not, suggesting that the supF tRNA is not a substrate for any mammalian aminoacyl–tRNA synthetase. These results open the possibility of using the supF tRNA aminoacylated with an amino acid analogue as a general approach for the site-specific insertion of amino acid analogues into proteins in mammalian cells. We discuss the possibility further of importing a mixture of amber and ochre suppressor tRNAs for the insertion of two different amino acid analogues into a protein and the potential use of suppressor tRNA import for treatment of some of the human genetic diseases caused by nonsense mutations. PMID:11717406

  15. The Acyl-Acyl Carrier Protein Synthetase from Synechocystis sp. PCC 6803 Mediates Fatty Acid Import1[C][W][OA

    PubMed Central

    von Berlepsch, Simon; Kunz, Hans-Henning; Brodesser, Susanne; Fink, Patrick; Marin, Kay; Flügge, Ulf-Ingo; Gierth, Markus

    2012-01-01

    The transfer of fatty acids across biological membranes is a largely uncharacterized process, although it is essential at membranes of several higher plant organelles like chloroplasts, peroxisomes, or the endoplasmic reticulum. Here, we analyzed loss-of-function mutants of the unicellular cyanobacterium Synechocystis sp. PCC 6803 as a model system to circumvent redundancy problems encountered in eukaryotic organisms. Cells deficient in the only cytoplasmic Synechocystis acyl-acyl carrier protein synthetase (SynAas) were highly resistant to externally provided α-linolenic acid, whereas wild-type cells bleached upon this treatment. Bleaching of wild-type cells was accompanied by a continuous increase of α-linolenic acid in total lipids, whereas no such accumulation could be observed in SynAas-deficient cells (Δsynaas). When SynAas was disrupted in the tocopherol-deficient, α-linolenic acid-hypersensitive Synechocystis mutant Δslr1736, double mutant cells displayed the same resistance phenotype as Δsynaas. Moreover, heterologous expression of SynAas in yeast (Saccharomyces cerevisiae) mutants lacking the major yeast fatty acid import protein Fat1p (Δfat1) led to the restoration of wild-type sensitivity against exogenous α-linolenic acid of the otherwise resistant Δfat1 mutant, indicating that SynAas is functionally equivalent to Fat1p. In addition, liposome assays provided direct evidence for the ability of purified SynAas protein to mediate α-[14C]linolenic acid retrieval from preloaded liposome membranes via the synthesis of [14C]linolenoyl-acyl carrier protein. Taken together, our data show that an acyl-activating enzyme like SynAas is necessary and sufficient to mediate the transfer of fatty acids across a biological membrane. PMID:22535424

  16. Importance of interferon inducible trans-membrane proteins and retinoic acid inducible gene I for influenza virus replication: A review.

    PubMed

    Suo, Siqingaowa; Ren, Xiaofeng

    2016-01-01

    Understanding the interplay between Influenza viruses and host cells is key to elucidating the pathogenesis of these viruses. Several host factors have been identified that exert antiviral functions; however, influenza viruses continue to replicate utilizing host cell machinery. Herein, we review the mechanisms of action of two host-derived proteins on conferring cellular resistance to the influenza virus; (1) the interferon inducible trans-membrane proteins, 1, 2 and 3, a recently identified family of early restriction factors; and (2) retinoic acid inducible gene I, a key mediator of antiviral immunity. These data may contribute to the design of novel and efficient anti-influenza treatments.

  17. The Play of Psychotherapy

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2012-01-01

    The author reviews the role of play within psychotherapy. She does not discuss the formal play therapy especially popular for young children, nor play from the Jungian perspective that encourages the use of the sand tray with adults. Instead, she focuses on the informal use of play during psychotherapy as it is orchestrated intuitively. Because…

  18. Plant-Specific Preprotein and Amino Acid Transporter Proteins Are Required for tRNA Import into Mitochondria1[OPEN

    PubMed Central

    Kubiszewski-Jakubiak, Szymon; Teixeira, Pedro F.; Narsai, Reena; Ivanova, Aneta; Megel, Cyrille; Schock, Annette; Kraus, Sabrina; Glaser, Elzbieta; Philippar, Katrin; Maréchal-Drouard, Laurence; Soll, Jürgen

    2016-01-01

    A variety of eukaryotes, in particular plants, do not contain the required number of tRNAs to support the translation of mitochondria-encoded genes and thus need to import tRNAs from the cytosol. This study identified two Arabidopsis (Arabidopsis thaliana) proteins, Tric1 and Tric2 (for tRNA import component), which on simultaneous inactivation by T-DNA insertion lines displayed a severely delayed and chlorotic growth phenotype and significantly reduced tRNA import capacity into isolated mitochondria. The predicted tRNA-binding domain of Tric1 and Tric2, a sterile-α-motif at the C-terminal end of the protein, was required to restore tRNA uptake ability in mitochondria of complemented plants. The purified predicted tRNA-binding domain binds the T-arm of the tRNA for alanine with conserved lysine residues required for binding. T-DNA inactivation of both Tric proteins further resulted in an increase in the in vitro rate of in organello protein synthesis, which was mediated by a reorganization of the nuclear transcriptome, in particular of genes encoding a variety of proteins required for mitochondrial gene expression at both the transcriptional and translational levels. The characterization of Tric1/2 provides mechanistic insight into the process of tRNA import into mitochondria and supports the theory that the tRNA import pathway resulted from the repurposing of a preexisting protein import apparatus. PMID:27789739

  19. Antioxidant activity of rosmarinic acid and its principal metabolites in chemical and cellular systems: Importance of physico-chemical characteristics.

    PubMed

    Adomako-Bonsu, Amma G; Chan, Sue Lf; Pratten, Margaret; Fry, Jeffrey R

    2017-04-01

    Persistent accumulation of reactive oxygen species causes cellular oxidative stress which contributes strongly towards the induction and progression of various diseases. Therapeutic focus has therefore shifted towards the use of antioxidants, with recent interest in those of plant origin. In the current study, rosmarinic acid (RA) and its key metabolites were evaluated in non-cellular and cellular antioxidant assays, using quercetin (Q) as a positive control. The non-cellular assay was performed as scavenging of DPPH radical, whilst the cellular assay was performed as protection from an oxidant stress. Radical-scavenging activity of RA and two of its primary metabolites, CA and DHPLA, were comparable to that of Q, whilst FA was of lower potency and m-CoA was inactive. In the cellular assay, RA and CA were markedly less potent than Q, with DHPLA, FA and m-CoA being inactive, this being true in short-term (5-h) or long-term (20-h) exposure conditions. However, antioxidant potency of Q and methyl rosmarinate, a non-ionisable ester of RA, was similar in the non-cellular and short-term cellular assays. It is proposed that marked ionisation of organic acids such as RA and its metabolites at physiological pH greatly limits their intracellular accumulation, and so attenuates intrinsic antioxidant ability demonstrated in the non-cellular assay. This study demonstrates some of the factors that prevent well-known phytochemicals from progressing further along the drug discovery chain.

  20. Perfluorinated acids in air, rain, snow, surface runoff, and lakes: relative importance of pathways to contamination of urban lakes.

    PubMed

    Kim, Seung-Kyu; Kannan, Kurunthachalam

    2007-12-15

    Concentrations of perfluorinated acids (PFAs) were measured in various environmental matrices (air, rain, snow, surface runoff water, and lake water) in an urban area, to enable identification of sources and pathways of PFAs to urban water bodies. Total PFA concentrations ranged from 8.28 to 16.0 pg/ m3 (mean 11.3) in bulk air (sum of vapor and particulate phases), 0.91 to 13.2 ng/L (6.19) in rainwater, 0.91 to 23.9 ng/L (7.98) in snow, 1.11-81.8 ng/L (15.1 ng/L) in surface runoff water (SRW), and 9.49 to 35.9 ng/L (21.8) in lake water. Perfluorooctanoic acid (PFOA) was the predominant compound, accounting for > 35% of the total PFA concentrations, in all environmental matrices analyzed. Concentrations and relative compositions of PFAs in SRW were similar to those found for urban lakes. SRW contributes to contamination by PFOA in urban lakes. The measured concentration ratios of FTOH to PFOA in air were 1-2 orders of magnitude lower than the ratios calculated based on an assumption of exclusive atmospheric oxidation of FTOHs. Nevertheless, the mass balance analysis suggested the presence of an unknown input pathway that could contribute to a significant amount of total PFOA loadings to the lake. Flux estimates of PFOA at the air-water interface in the urban lake suggest net volatilization from water.

  1. Amino acids outside of the loops that define the agonist binding site are important for ligand binding to insect nicotinic acetylcholine receptors.

    PubMed

    Liu, Zewen; Han, Zhaojun; Liu, Shuhua; Zhang, Yixi; Song, Feng; Yao, Xiangmei; Gu, Jianhua

    2008-07-01

    Nicotinic acetylcholine (ACh) receptors (nAChRs) are the targets of several kinds of insecticides. Based on the mutagenesis studies of Torpedo californica nAChRs and solved structure of a molluscan, glial-derived soluble ACh-binding protein, a model of the agonist site was constructed with contributing amino acids from three distinct loops (A, B, and C) of the alpha subunits and another three loops (D, E, and F) of the non-alpha subunits. According to this model, most insect nAChR subunits can form the functional heteromeric or homomeric receptors. Actually, insect subunits themselves did not form any functional receptor at various combinations as yet, and only part of them can form the functional receptors with vertebrate non-alpha subunits. These findings suggested that the agonist binding for insect nAChRs was not only contributed by those key amino acids in six loops, but also some unidentified amino acids from other regions. In our previous studies on nAChRs for Nilaparvata lugens, a target-site mutation (Y151S) was found within two alpha subunits (Nlalpha1 and Nlalpha3). In Drosophila S2 cells and Xenopus oocytes, Nlalpha1 can form functional receptors with rat beta2 subunit. However, the same thing was not observed in Nlalpha3. In the present paper, by exchanging the corresponding regions between Nlalpha1 and Nlalpha3 to generate different chimeras, amino acid residues or residue clusters in the regions outside the six loops were found to play essential roles in agonist binding, especially for the amino acid clusters between loop B and C. This result indicated that the residues in the six loops could be necessary, but not enough for the activity of agonist binding.

  2. Pretend Play in the Early Childhood Classroom

    ERIC Educational Resources Information Center

    McEntire, Nancy

    2009-01-01

    This article presents and summarizes recent resources related to pretend play in the early childhood classroom. These include "Contemporary Perspectives on Play in Early Childhood Education" by Olivia N. Sarachoe and Bernard Spodek; "Dramatic Play: Bring It Back" by Tammy Benson; and "The Importance of Being Playful" by Elena Bodrova and Deborah…

  3. Play Therapy: Practice, Issues, and Trends

    ERIC Educational Resources Information Center

    Homeyer, Linda E.; Morrison, Mary O.

    2008-01-01

    Play therapy is an effective means of responding to the mental health needs of young children and is widely accepted as a valuable and developmentally appropriate intervention. The authors discuss the importance of play in development, the therapeutic benefits of play, the rich history of play therapy, and recent research and current issues and…

  4. Amino Acids in the Basic Domain of Epstein-Barr Virus ZEBRA Protein Play Distinct Roles in DNA Binding, Activation of Early Lytic Gene Expression, and Promotion of Viral DNA Replication

    PubMed Central

    Heston, Lee; El-Guindy, Ayman; Countryman, Jill; Dela Cruz, Charles; Delecluse, Henri-Jacques; Miller, George

    2006-01-01

    The ZEBRA protein of Epstein-Barr virus (EBV) drives the viral lytic cycle cascade. The capacity of ZEBRA to recognize specific DNA sequences resides in amino acids 178 to 194, a region in which 9 of 17 residues are either lysine or arginine. To define the basic domain residues essential for activity, a series of 46 single-amino-acid-substitution mutants were examined for their ability to bind ZIIIB DNA, a high-affinity ZEBRA binding site, and for their capacity to activate early and late EBV lytic cycle gene expression. DNA binding was obligatory for the protein to activate the lytic cascade. Nineteen mutants that failed to bind DNA were unable to disrupt latency. A single acidic replacement of a basic amino acid destroyed DNA binding and the biologic activity of the protein. Four mutants that bound weakly to DNA were defective at stimulating the expression of Rta, the essential first target of ZEBRA in lytic cycle activation. Four amino acids, R183, A185, C189, and R190, are likely to contact ZIIIB DNA specifically, since alanine or valine substitutions at these positions drastically weakened or eliminated DNA binding. Twenty-three mutants were proficient in binding to ZIIIB DNA. Some DNA binding-proficient mutants were refractory to supershift by BZ-1 monoclonal antibody (epitope amino acids 214 to 230), likely as the result of the increased solubility of the mutants. Mutants competent to bind DNA could be separated into four functional groups: the wild-type group (eight mutants), a group defective at activating Rta (five mutants, all with mutations at the S186 site), a group defective at activating EA-D (three mutants with the R179A, S186T, and K192A mutations), and a group specifically defective at activating late gene expression (seven mutants). Three late mutants, with a Y180A, Y180E, or K188A mutation, were defective at stimulating EBV DNA replication. This catalogue of point mutants reveals that basic domain amino acids play distinct functions in binding

  5. In Silico profiling of deleterious amino acid substitutions of potential pathological importance in haemophlia A and haemophlia B

    PubMed Central

    2012-01-01

    Background In this study, instead of current biochemical methods, the effects of deleterious amino acid substitutions in F8 and F9 gene upon protein structure and function were assayed by means of computational methods and information from the databases. Deleterious substitutions of F8 and F9 are responsible for Haemophilia A and Haemophilia B which is the most common genetic disease of coagulation disorders in blood. Yet, distinguishing deleterious variants of F8 and F9 from the massive amount of nonfunctional variants that occur within a single genome is a significant challenge. Methods We performed an in silico analysis of deleterious mutations and their protein structure changes in order to analyze the correlation between mutation and disease. Deleterious nsSNPs were categorized based on empirical based and support vector machine based methods to predict the impact on protein functions. Furthermore, we modeled mutant proteins and compared them with the native protein for analysis of protein structure stability. Results Out of 510 nsSNPs in F8, 378 nsSNPs (74%) were predicted to be 'intolerant' by SIFT, 371 nsSNPs (73%) were predicted to be 'damaging' by PolyPhen and 445 nsSNPs (87%) as 'less stable' by I-Mutant2.0. In F9, 129 nsSNPs (78%) were predicted to be intolerant by SIFT, 131 nsSNPs (79%) were predicted to be damaging by PolyPhen and 150 nsSNPs (90%) as less stable by I-Mutant2.0. Overall, we found that I-Mutant which emphasizes support vector machine based method outperformed SIFT and PolyPhen in prediction of deleterious nsSNPs in both F8 and F9. Conclusions The models built in this work would be appropriate for predicting the deleterious amino acid substitutions and their functions in gene regulation which would be useful for further genotype-phenotype researches as well as the pharmacogenetics studies. These in silico tools, despite being helpful in providing information about the nature of mutations, may also function as a first-pass filter to

  6. Regulation of Leaf Starch Degradation by Abscisic Acid Is Important for Osmotic Stress Tolerance in Plants[OPEN

    PubMed Central

    Thalmann, Matthias; Pazmino, Diana; Seung, David; Horrer, Daniel; Nigro, Arianna; Meier, Tiago; Zeeman, Samuel C.; Santelia, Diana

    2016-01-01

    Starch serves functions that range over a timescale of minutes to years, according to the cell type from which it is derived. In guard cells, starch is rapidly mobilized by the synergistic action of β-AMYLASE1 (BAM1) and α-AMYLASE3 (AMY3) to promote stomatal opening. In the leaves, starch typically accumulates gradually during the day and is degraded at night by BAM3 to support heterotrophic metabolism. During osmotic stress, starch is degraded in the light by stress-activated BAM1 to release sugar and sugar-derived osmolytes. Here, we report that AMY3 is also involved in stress-induced starch degradation. Recently isolated Arabidopsis thaliana amy3 bam1 double mutants are hypersensitive to osmotic stress, showing impaired root growth. amy3 bam1 plants close their stomata under osmotic stress at similar rates as the wild type but fail to mobilize starch in the leaves. 14C labeling showed that amy3 bam1 plants have reduced carbon export to the root, affecting osmolyte accumulation and root growth during stress. Using genetic approaches, we further demonstrate that abscisic acid controls the activity of BAM1 and AMY3 in leaves under osmotic stress through the AREB/ABF-SnRK2 kinase-signaling pathway. We propose that differential regulation and isoform subfunctionalization define starch-adaptive plasticity, ensuring an optimal carbon supply for continued growth under an ever-changing environment. PMID:27436713

  7. Evolutionary Importance of the Intramolecular Pathways of Hydrolysis of Phosphate Ester Mixed Anhydrides with Amino Acids and Peptides

    PubMed Central

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-01-01

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide–phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation. PMID:25501391

  8. Evolutionary Importance of the Intramolecular Pathways of Hydrolysis of Phosphate Ester Mixed Anhydrides with Amino Acids and Peptides

    NASA Astrophysics Data System (ADS)

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-12-01

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide-phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation.

  9. Evolutionary importance of the intramolecular pathways of hydrolysis of phosphate ester mixed anhydrides with amino acids and peptides.

    PubMed

    Liu, Ziwei; Beaufils, Damien; Rossi, Jean-Christophe; Pascal, Robert

    2014-12-11

    Aminoacyl adenylates (aa-AMPs) constitute essential intermediates of protein biosynthesis. Their polymerization in aqueous solution has often been claimed as a potential route to abiotic peptides in spite of a highly efficient CO2-promoted pathway of hydrolysis. Here we investigate the efficiency and relevance of this frequently overlooked pathway from model amino acid phosphate mixed anhydrides including aa-AMPs. Its predominance was demonstrated at CO2 concentrations matching that of physiological fluids or that of the present-day ocean, making a direct polymerization pathway unlikely. By contrast, the occurrence of the CO2-promoted pathway was observed to increase the efficiency of peptide bond formation owing to the high reactivity of the N-carboxyanhydride (NCA) intermediate. Even considering CO2 concentrations in early Earth liquid environments equivalent to present levels, mixed anhydrides would have polymerized predominantly through NCAs. The issue of a potential involvement of NCAs as biochemical metabolites could even be raised. The formation of peptide-phosphate mixed anhydrides from 5(4H)-oxazolones (transiently formed through prebiotically relevant peptide activation pathways) was also observed as well as the occurrence of the reverse cyclization process in the reactions of these mixed anhydrides. These processes constitute the core of a reaction network that could potentially have evolved towards the emergence of translation.

  10. Sugar-coated proteins: the importance of degree of polymerisation of oligo-galacturonic acid on protein binding and aggregation.

    PubMed

    Xu, Amy Y; Melton, Laurence D; Ryan, Timothy M; Mata, Jitendra P; Jameson, Geoffrey B; Rekas, Agata; Williams, Martin A K; McGillivray, Duncan J

    2017-04-05

    We have simplified the structural heterogeneity of protein-polysaccharide binding by investigating protein binding to oligosaccharides. The interactions between bovine beta-lactoglobulin A (βLgA) and oligo-galacturonic acids (OGAs) with various numbers of sugar residues have been investigated with a range of biophysical techniques. We show that the βLgA-OGA interaction is critically dependent on the length of the oligosaccharide. Isothermal titration calorimetry results suggest that a minimum length of 7 or 8 sugar residues is required in order to exhibit appreciable exothermic interactions with βLgA - shorter oligosaccharides show no enthalpic interactions at any concentration ratio. When titrating βLgA into OGAs with more than 7-8 sugar residues the sample solution also became turbid with increasing amounts of βLgA, indicating the formation of macroscopic assemblies. Circular dichroism, thioflavin T fluorescence and small angle X-ray/neutron scattering experiments revealed two structural regimes during the titration. When OGAs were in excess, βLgA formed discrete assemblies upon OGA binding, and no subsequent aggregation was observed. However, when βLgA was present in excess, multi-scale structures were formed and this eventually led to the separation of the solution into two liquid-phases.

  11. Playing It Right

    ERIC Educational Resources Information Center

    Tooley, Kay

    1973-01-01

    Described is one technique, referred to as "playing it right," to aid the therapist in the treatment of borderline children. "Playing it right" is based on the introduction of reality rules into the fantasy world of the borderline child. (CS)

  12. Role-Playing Mitosis.

    ERIC Educational Resources Information Center

    Wyn, Mark A.; Stegink, Steven J.

    2000-01-01

    Introduces a role playing activity that actively engages students in the learning process of mitosis. Students play either chromosomes carrying information, or cells in the cell membrane. (Contains 11 references.) (Author/YDS)

  13. Outdoor Creative Play Areas.

    ERIC Educational Resources Information Center

    Miller, Peggy L.

    Guidelines are given for the development of outdoor play areas on school sites to provide children with natural areas and simple facilities for creative play. Site selection, analysis, and development are discussed. Natural, topographical features of the environment and natural play equipment are suggested. Illustrations are also presented to aid…

  14. The Excellence of Play.

    ERIC Educational Resources Information Center

    Moyles, Janet R., Ed.

    Recognizing that for young children, play is a tool for learning, this book compiles contributions by different authors, reflecting both up-to-date research and current classroom practice as they relate to children's play. Part 1 of the book explores the value of play as a cross-cultural concept as well as one rooted in the Western world. Gender…

  15. Life! Through Play.

    ERIC Educational Resources Information Center

    Van Anne, Nancy

    This speech presents a review of research concerning the nature of play. Some of the formal characteristics of play are: (a) it is distinct from ordinary life in its "temporariness" and its limitless location; (b) there is an element of tension in play that leads to uncertainty concerning the outcome but at the same time provides the opportunity…

  16. Incorporation of n-3 fatty acids into plasma and liver lipids of rats: importance of background dietary fat.

    PubMed

    MacDonald-Wicks, Lesley K; Garg, Manohar L

    2004-06-01

    The health benefits of long-chain n-3 PUFA (20:5n-3 and 22:6n-3) depend on the extent of incorporation of these FA into plasma and tissue lipids. This study aimed to investigate the effect of the background dietary fat (saturated, monounsaturated, or n-6 polyunsaturated) on the quantitative incorporation of dietary 18:3n-3 and its elongated and desaturated products into the plasma and the liver lipids of rats. Female weanling Wistar rats (n = 54) were randomly assigned to six diet groups (n = 9). The fat added to the semipurified diets was tallow (SFA), tallow plus linseed oil (SFA-LNA), sunola oil (MUFA), sunola oil plus linseed oil (MUFA-LNA), sunflower oil (PUFA), or sunflower oil plus linseed oil (PUFA-LNA). At the completion of the 4-wk feeding period, quantitative FA analysis of the liver and plasma was undertaken by GC. The inclusion of linseed oil in the rat diets increased the level of 18:3n-3, 20:5n-3, and, to a smaller degree, 22:6n-3 in plasma and liver lipids regardless of the background dietary fat. The extent of incorporation of 18:3n-3, 20:5n-3, and 22:5n-3 followed the order SFA-LNA > MUFA-LNA > PUFA-LNA. Levels of 22:6n-3 were increased to a similar extent regardless of the type of major fat in the rat diets. This indicates that the background diet affects the incorporation in liver and plasma FA pools of the n-3 PUFA with the exception of 22:6n-3 and therefore the background diet has the potential to influence the already established health benefits of long-chain n-3 fatty acids.

  17. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  18. Crystal structure of Clostridium acetobutylicum Aspartate kinase (CaAK): An important allosteric enzyme for amino acids production.

    PubMed

    Manjasetty, Babu A; Chance, Mark R; Burley, Stephen K; Panjikar, Santosh; Almo, Steven C

    2014-09-01

    Aspartate kinase (AK) is an enzyme which is tightly regulated through feedback control and responsible for the synthesis of 4-phospho-L-aspartate from L-aspartate. This intermediate step is at an important branch point where one path leads to the synthesis of lysine and the other to threonine, methionine and isoleucine. Concerted feedback inhibition of AK is mediated by threonine and lysine and varies between the species. The crystal structure of biotechnologically important Clostridium acetobutylicum aspartate kinase (CaAK; E.C. 2.7.2.4; Mw=48,030Da; 437aa; SwissProt: Q97MC0) has been determined to 3Å resolution. CaAK acquires a protein fold similar to the other known structures of AKs despite the low sequence identity (<30%). It is composed of two domains: an N-terminal catalytic domain (kinase) domain and a C-terminal regulatory domain further comprised of two small domains belonging to the ACT domain family. Pairwise comparison of 12 molecules in the asymmetric unit helped to identify the bending regions which are in the vicinity of ATP binding site involved in domain movements between the catalytic and regulatory domains. All 12 CaAK molecules adopt fully open T-state conformation leading to the formation of three tetramers unique among other similar AK structures. On the basis of comparative structural analysis, we discuss tetramer formation based on the large conformational changes in the catalytic domain associated with the lysine binding at the regulatory domains. The structure described herein is homologous to a target in wide-spread pathogenic (toxin producing) bacteria such as Clostridium tetani (64% sequence identity) suggesting the potential of the structure solved here to be applied for modeling drug interactions. CaAK structure may serve as a guide to better understand and engineer lysine biosynthesis for the biotechnology industry.

  19. Stabilization of secondary structure elements by specific combinations of hydrophilic and hydrophobic amino acid residues is more important for proteins encoded by GC-poor genes.

    PubMed

    Khrustalev, Vladislav Victorovich; Barkovsky, Eugene Victorovich

    2012-12-01

    Stabilization of secondary structure elements by specific combinations of hydrophobic and hydrophilic amino acids has been studied by the way of analysis of pentapeptide fragments from twelve partial bacterial proteomes. PDB files describing structures of proteins from species with extremely high and low genomic GC-content, as well as with average G + C were included in the study. Amino acid residues in 78,009 pentapeptides from alpha helices, beta strands and coil regions were classified into hydrophobic and hydrophilic ones. The common propensity scale for 32 possible combinations of hydrophobic and hydrophilic amino acid residues in pentapeptide has been created: specific pentapeptides for helix, sheet and coil were described. The usage of pentapeptides preferably forming alpha helices is decreasing in alpha helices of partial bacterial proteomes with the increase of the average genomic GC-content in first and second codon positions. The usage of pentapeptides preferably forming beta strands is increasing in coil regions and in helices of partial bacterial proteomes with the growth of the average genomic GC-content in first and second codon positions. Due to these circumstances the probability of coil-sheet and helix-sheet transitions should be increased in proteins encoded by GC-rich genes making them prone to form amyloid in certain conditions. Possible causes of the described fact that importance of alpha helix and coil stabilization by specific combinations of hydrophobic and hydrophilic amino acids is growing with the decrease of genomic GC-content have been discussed.

  20. Characterization of a novel cDNA encoding a short venom peptide derived from venom gland of scorpion Buthus martensii Karsch: trans-splicing may play an important role in the diversification of scorpion venom peptides.

    PubMed

    Zeng, Xian-Chun; Luo, Feng; Li, Wen-Xin

    2006-04-01

    A novel cDNA clone (named BmKT-u) which is a hybrid molecule of the 5'-terminal region of BmKT' cDNA and the 3'-terminal region of an undocumented cDNA (named BmKu), was isolated from a cDNA library made from the venom gland of scorpion Buthus martensii Karsch. BmKT-u codes for a 30 amino acid residue precursor peptide composed of a 20-residue signal sequence, and a putative 10-residue novel mature peptide. Northern blot hybridization showed BmKT-u cDNA is generated from a transcript. RT-PCR experiments excluded the possibility that BmKT-u cDNA is an artifact generated during reverse transcription. Genomic amplifications performed with three pairs of BmKT-u gene-specific primers showed the BmKT-u gene does not exist in the genome of the scorpion as a single transcriptional unit. Genomic cloning for BmKT' showed that the BmKT' gene contains an intron of 509 bp inserted into the region encoding the C-terminal region of the signal peptide. A sequence alignment comparison of the cDNA of BmKT-u with genomic BmKT' revealed that the junction site of the hybrid molecule is located at the 5'-splicing site of the intron. The data suggest that the BmKT-u transcript is a naturally occurring mature mRNA that is generated by trans-splicing. Trans-splicing may contribute to the diversity of venom peptides from venomous animals.

  1. Light signalling mediated by phytochrome plays an important role in cold-induced gene expression through the C-repeat/dehydration responsive element (C/DRE) in Arabidopsis thaliana.

    PubMed

    Kim, Hyoun-Joung; Kim, Yun-Kyoung; Park, Jin-Young; Kim, Jungmook

    2002-03-01

    Low temperature induces a number of genes that encode the proteins promoting tolerance to freezing, mediated by ABA-dependent and ABA-independent pathways in plants. The cis-acting element called C/DRE is known to respond to low temperature independently of ABA action. To investigate the signalling and network of ABA-independent pathways, the transgenic Arabidopsis plants were generated containing several copies of the C/DRE derived from cor15a gene with a minimal promoter fused to a GUS reporter gene. The transgenic plants containing four copies of the C/DRE (4C/DRE-GUS) showed responsiveness to cold and drought treatments and were used for characterization of cold signalling and cross-talk. Cold-induced GUS expression was inhibited by okadaic acid at 1 nM, indicating that protein phosphatase 2A might act as a positive regulator. Light was shown to activate cold- and drought-induced GUS expression. Photo-reversibility of the GUS mRNA by red and far-red light with concomitant cold treatment suggests a role of phytochrome as a photoreceptor in mediating light signalling to activate the cold-induced gene expression through the C/DRE. Furthermore, GUS expression analysis in phyA or phyB or phyAphyB mutant backgrounds showed that phytochrome B is a primary photoreceptor responsible for the activation of cold-stress signalling in response to light. Light enhanced the induction kinetics of CBF1, 2, and 3 encoding the cognate transcription factors, and cor15a, in a consecutive manner compared to the dark condition in the cold, suggesting that the connection point between cold and light signalling mediated by phytochrome is at a higher step than the expression of CBF genes.

  2. Play and Development From an Ethological Perspective

    ERIC Educational Resources Information Center

    Vandenberg, Brian

    1978-01-01

    A review of play in nonhuman animals indicates that play increases with phylogenetic status, is important for mature social development in more advanced species, reflects intentional activity, and is essential for the development of tool-using strategies. (Author)

  3. A Conserved Aspartic Acid Is Important for Agonist (VUAA1) and Odorant/Tuning Receptor-Dependent Activation of the Insect Odorant Co-Receptor (Orco)

    PubMed Central

    Kumar, Brijesh N.; Taylor, Robert W.; Pask, Gregory M.; Zwiebel, Laurence J.; Newcomb, Richard D.; Christie, David L.

    2013-01-01

    Insect odorant receptors function as heteromeric odorant-gated cation channels comprising a conventional odorant-sensitive tuning receptor, and a conserved co-receptor (Orco). An Orco agonist, VUAA1, is able to activate both heteromeric and homomeric Orco-containing channels. Very little is known about specific residues in Orco that contribute to cation permeability and gating. We investigated the importance of two conserved Asp residues, one in each of transmembrane domains 5 and 7, for channel function by mutagenesis. Drosophila melanogaster Orco and its substitution mutants were expressed in HEK cells and VUAA1-stimulated channel activity was determined by Ca2+ influx and whole-cell patch clamp electrophysiology. Substitution of D466 in transmembrane 7 with amino acids other than glutamic acid resulted in a substantial reduction in channel activity. The D466E Orco substitution mutant was ∼2 times more sensitive to VUAA1. The permeability of the D466E Orco mutant to cations was unchanged relative to wild-type Orco. When D466E Orco is co-expressed with a conventional tuning odorant receptor, the heteromeric complex also shows increased sensitivity to an odorant. Thus, the effect of the D466E mutation is not specific to VUAA1 agonism or dependent on homomeric Orco assembly. We suggest the gain-of-activation characteristic of the D466E mutant identifies an amino acid that is likely to be important for activation of both heteromeric and homomeric insect odorant receptor channels. PMID:23894621

  4. Contrasting responses of root morphology and root-exuded organic acids to low phosphorus availability in three important food crops with divergent root traits

    PubMed Central

    Wang, Yan-Liang; Almvik, Marit; Clarke, Nicholas; Eich-Greatorex, Susanne; Øgaard, Anne Falk; Krogstad, Tore; Lambers, Hans; Clarke, Jihong Liu

    2015-01-01

    Phosphorus (P) is an important element for crop productivity and is widely applied in fertilizers. Most P fertilizers applied to land are sorbed onto soil particles, so research on improving plant uptake of less easily available P is important. In the current study, we investigated the responses in root morphology and root-exuded organic acids (OAs) to low available P (1 μM P) and sufficient P (50 μM P) in barley, canola and micropropagated seedlings of potato—three important food crops with divergent root traits, using a hydroponic plant growth system. We hypothesized that the dicots canola and tuber-producing potato and the monocot barley would respond differently under various P availabilities. WinRHIZO and liquid chromatography triple quadrupole mass spectrometry results suggested that under low P availability, canola developed longer roots and exhibited the fastest root exudation rate for citric acid. Barley showed a reduction in root length and root surface area and an increase in root-exuded malic acid under low-P conditions. Potato exuded relatively small amounts of OAs under low P, while there was a marked increase in root tips. Based on the results, we conclude that different crops show divergent morphological and physiological responses to low P availability, having evolved specific traits of root morphology and root exudation that enhance their P-uptake capacity under low-P conditions. These results could underpin future efforts to improve P uptake of the three crops that are of importance for future sustainable crop production. PMID:26286222

  5. Properties of a recombinant human hemoglobin with aspartic acid 99(beta), an important intersubunit contact site, substituted by lysine.

    PubMed Central

    Yanase, H.; Cahill, S.; Martin de Llano, J. J.; Manning, L. R.; Schneider, K.; Chait, B. T.; Vandegriff, K. D.; Winslow, R. M.; Manning, J. M.

    1994-01-01

    Site-directed mutagenesis of an important subunit contact site, Asp-99(beta), by a Lys residue (D99K(beta)) was proven by sequencing the entire beta-globin gene and the mutant tryptic peptide. Oxygen equilibrium curves of the mutant hemoglobin (Hb) (2-15 mM in heme) indicated that it had an increased oxygen affinity and a lowered but significant amount of cooperativity compared to native HbA. However, in contrast to normal HbA, oxygen binding of the recombinant mutant Hb was only marginally affected by the allosteric regulators 2,3-diphosphoglycerate or inositol hexaphosphate and was not at all responsive to chloride. The efficiency of oxygen binding by HbA in the presence of allosteric regulators was limited by the mutant Hb. At concentrations of 0.2 mM or lower in heme, the mutant D99K(beta) Hb was predominantly a dimer as demonstrated by gel filtration, haptoglobin binding, fluorescence quenching, and light scattering. The purified dimeric recombinant Hb mutant exists in 2 forms that are separable on isoelectric focusing by about 0.1 pH unit, in contrast to tetrameric hemoglobin, which shows 1 band. These mutant forms, which were present in a ratio of 60:40, had the same masses for their heme and globin moieties as determined by mass spectrometry. The elution positions of the alpha- and beta-globin subunits on HPLC were identical. Circular dichroism studies showed that one form of the mutant Hb had a negative ellipticity at 410 nm and the other had positive ellipticity at this wavelength. The findings suggest that the 2 D99K(beta) recombinant mutant forms have differences in their heme-protein environments. PMID:7987216

  6. Amino acid residues in the GerAB protein important in the function and assembly of the alanine spore germination receptor of Bacillus subtilis 168.

    PubMed

    Cooper, Gareth R; Moir, Anne

    2011-05-01

    The paradigm gerA operon is required for endospore germination in response to c-alanine as the sole germinant, and the three protein products, GerAA, GerAB, and GerAC are predicted to form a receptor complex in the spore inner membrane. GerAB shows homology to the amino acid-polyamine-organocation (APC) family of single-component transporters and is predicted to be an integral membrane protein with 10 membrane-spanning helices. Site-directed mutations were introduced into the gerAB gene at its natural location on the chromosome. Alterations to some charged or potential helix-breaking residues within membrane spans affected receptor function dramatically. In some cases, this is likely to reflect the complete loss of the GerA receptor complex, as judged by the absence of the germinant receptor protein GerAC, which suggests that the altered GerAB protein itself may be unstable or that the altered structure destabilizes the complex. Mutants that have a null phenotype for Instituto de Biotecnología de León, INBIOTEC, Parque Científico de León, Av. Real, 1, 24006 León, Spain-alanine germination but retain GerAC protein at near-normal levels are more likely to define amino acid residues of functional, rather than structural, importance. Single-amino-acid substitutions in each of the GerAB and GerAA proteins can prevent incorporation of GerAC protein into the spore; this provides strong evidence that the proteins within a specific receptor interact and that these interactions are required for receptor assembly. The lipoprotein nature of the GerAC receptor subunit is also important; an amino acid change in the prelipoprotein signal sequence in the gerAC1 mutant results in the absence of GerAC protein from the spore.

  7. Spatial distribution and importance of potential perfluoroalkyl acid precursors in urban rivers and sewage treatment plant effluent--case study of Tama River, Japan.

    PubMed

    Ye, Feng; Tokumura, Masahiro; Islam, Md Saiful; Zushi, Yasuyuki; Oh, Jungkeun; Masunaga, Shigeki

    2014-12-15

    Production and use of perfluorooctane sulfonate (PFOS) is regulated worldwide. However, numerous potential precursors that eventually decompose into PFOS and other perfluoroalkyl acids (PFAAs) such as perfluorooctanoic acid (PFOA) are still being used and have not been studied in detail. Therefore, knowledge about the levels and sources of the precursors is essential. We investigated the total concentration of potential PFAA precursors in the Tama River, which is one of the major rivers flowing into the Tokyo Bay, by converting all the perfluorinated carboxylic acid (PFCA) and perfluoroalkyl sulfonic acid (PFSA) precursors into PFCAs by chemical oxidation. The importance of controlling PFAA precursors was determined by calculating the ratios of PFCAs formed by oxidation to the PFAAs originally present (ΣΔ[PFCAC4-C12]/Σ[PFAAs]before oxidation) (average = 0.28 and 0.69 for main and tributary branch rivers, respectively). Higher total concentrations of Δ[PFCAs] were found in sewage treatment plant (STP) effluents. However, the ratios found in the effluents were lower (average = 0.21) than those found in the river water samples, which implies the decomposition of some precursors into PFAAs during the treatment process. On the other hand, higher ratios were observed in the upstream water samples and the existence of emission sources other than the STP effluents was indicated. This study showed that although the treatment process converting a part of the PFAA precursors into PFAAs, STPs were important sources of precursors to the Tama River. To reduce the levels of PFAAs in the aquatic environment, it is necessary to reduce the emission of the PFAA precursors as well.

  8. Waist circumference, body mass index, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal liver function tests in the Taiwanese population.

    PubMed

    Hsieh, Meng-Hsuan; Lin, Wen-Yi; Chien, Hsu-Han; Chien, Li-Ho; Huang, Chao-Kuan; Yang, Jeng-Fu; Chang, Ning-Chia; Huang, Chung-Feng; Wang, Chao-Ling; Chuang, Wan-Long; Yu, Ming-Lung; Dai, Chia-Yen; Ho, Chi-Kung

    2012-09-01

    Several studies have found that metabolic syndrome and uric acid level are related to abnormal liver function test results. The aim of this study was to explore the associations of risk factors [including blood pressure, blood sugar, total cholesterol, triglyceride, uric acid, waist circumference and body mass index (BMI) measurements] with abnormal liver function in the Taiwanese population.In total, 11,411 Taiwanese adults were enrolled in this study. Blood pressure was assessed according to the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure criteria, fasting blood sugar level according to the Bureau of Health Promotion, Department of Health, R.O.C., criteria, total cholesterol and triglyceride levels according to the Third Report of the National Cholesterol Education Program Adult Treatment Panel III criteria, BMI according to the Asia-Pacific criteria, and waist circumference according to the Revised Diagnostic Criteria of Metabolic Syndrome in Taiwan. The prevalence of a past history of hypertension and diabetes mellitus was 17.7% and 6.5%, respectively, and the rates of abnormal measurements of blood pressure, BMI, waist circumference, fasting blood sugar, triglyceride, total cholesterol, uric acid (male/female), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were 76.2%, 67.6%, 40.0%, 28.6%, 30.6%, 57.3%, 37.9%/21.9%, 14.6% and 21.3%, respectively. Multivariate analysis showed that waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels were related to abnormal AST and ALT (p<0.05), but the odds ratio for waist circumference was larger than that for BMI. In conclusion, waist circumference, BMI, serum uric acid, blood sugar, and triglyceride levels are important risk factors for abnormal AST and ALT readings in Taiwanese adults. Waist circumference might be a better indicator of risk of abnormal liver function than BMI.

  9. The rice semi-dwarf mutant sd37, caused by a mutation in CYP96B4, plays an important role in the fine-tuning of plant growth.

    PubMed

    Zhang, Jie; Liu, Xiaoqiang; Li, Shuyu; Cheng, Zhukuan; Li, Chuanyou

    2014-01-01

    Plant cytochrome P450 has diverse roles in developmental processes and in the response to environmental cues. Here, we characterized the rice (Oryza sativa L ssp. indica cultivar 3037) semi-dwarf mutant sd37, in which the gene CYP96B4 (Cytochrome P450 96B subfamily) was identified and confirmed as the target by map-based cloning and a complementation test. A point mutation in the SRS2 domain of CYP96B4 resulted in a threonine to lysine substitution in the sd37 mutant. Examination of the subcellular localization of the protein revealed that SD37 was ER-localized protein. And SD37 was predominantly expressed in the shoot apical meristem and developing leaf and root maturation zone but not in the root apical meristem. The sd37 leaves, panicles, and seeds were smaller than those of the wild type. Histological analysis further revealed that a decrease in cell number in the mutant, specifically in the shoots, was the main cause of the dwarf phenotype. Microarray analysis demonstrated that the expression of several cell division-related genes was disturbed in the sd37 mutant. In addition, mutation or strongly overexpression of SD37 results in dwarf plants but moderate overexpression increases plant height. These data suggest that CYP96B4 may be an important regulator of plant growth that affects plant height in rice.

  10. Reactivity of NaCl with Secondary Organic Acids: An Important Mechanism of the Chloride Depletion in Sea Salt Particles Mixed with Organic Materials

    NASA Astrophysics Data System (ADS)

    Wang, B.; Laskin, A.; Kelly, S.; Gilles, M. K.; Shilling, J. E.; Zelenyuk, A.; Wilson, J. M.; Tivanski, A.

    2012-12-01

    Sea salt particles, one of the major sources of atmospheric aerosols, undergo complex multi-phase reactions and have profound consequences on their physical and chemical properties, thus on climate. Depletion of chloride in sea salt particles was reported in previous field studies and was attributed to the acid displacement of sea salt chlorides with inorganic acids, such as nitric and sulfuric acids. Some studies have also showed that the chloride deficit cannot be fully compensated for this mechanism. We present an important pathway contributing to this chloride depletion: reactions of weak organic acids with sea salt particles. NaCl particles internally mixed with secondary organic materials generated from the reactions of limonene and alpha-pinene with ozone served as surrogates for sea salt particles mixed with organic materials. Chemical imaging analysis of these particles was conducted using complementary techniques including computer controlled scanning electron microscopy with energy dispersive analysis of X-rays (CCSEM/EDX), scanning transmission X-ray microscopy with near edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS), and micro-fourier transform infrared spectroscopy (micro-FTIR). Substantial chloride depletion and formation of organic salts were observed along with distinctive changes in particle morphology after hydration/dehydration processes. The results indicate that secondary organic acids can effectively react with NaCl particles resulting in displacement of chloride and release of gaseous HCl. This is consistent with a recent field study showing chloride depletion in sea salt particles mixed with organic materials which cannot be fully compensated by inorganic acid displacement. Although the formation of the organic salts is not thermodynamically favored in bulk aqueous solution, these reactions are driven by the high volatility and evaporation of gaseous HCl in particles, especially during hydration/dehydration processes. The

  11. Wnt/β-catenin signaling plays an important role in the protective effects of FDP-Sr against oxidative stress induced apoptosis in MC3T3-E1 cell.

    PubMed

    Qi, Huan-Huan; Bao, Jun; Zhang, Qi; Ma, Bo; Gu, Gui-Ying; Zhang, Peng-Ling; Ou-Yang, Gang; Wu, Zi-Mei; Ying, Han-Jie; Ou-Yang, Ping-Kai

    2016-10-01

    Strontium fructose 1,6-diphosphate (FDP-Sr) is a new strontium-containing compound. The primary aim of this study was to clarify whether the structure component of FDP-Sr, FDP could benefit the protective effect of Sr (II) against oxidative stress induced apoptosis, and meanwhile to further explore the important role of Wnt/β-catenin signaling in the anti-apoptosis effect of FDP-Sr in response to oxidative stress induced by H2O2 in an osteoblastic MC3T3-E1 cell line. Results showed that FDP-Sr could improve the osteoblastic differentiation under oxidative stress with induced cell proliferation and improved mineralization. The inhibition effect of FDP-Sr on cell apoptosis induced by H2O2 was proved by reduced reactive oxygen species production and activated caspase3. Under oxidative stress, mRNA and protein levels of phospho-β-catenin reduced, while β-catenin increased in the FDP-Sr treatment cell, leaded to the up-regulations of Runx2 and OPG at both mRNA and protein levels, finally improved the differentiation of osteoblasts. By the engagement of Wnt/β-catenin pathway's inhibitor (XAV-939), the protective effects of FDP-Sr on osteoblastic differentiation against oxidative stress were repressed along with inhibited wnt/β-catenin signaling and reduced mRNA and protein levels of Runx2 and OPG. In conclusion, FDP-Sr was demonstrated to protect osteoblast differentiation from oxidative damage induced by H2O2 through up-regulation of Wnt/β-catenin signaling, and FDP in FDP-Sr was able to directly improve the oxidative stress injury through its ROS scavenging ability.

  12. Where are kids getting their empty calories? Stores, schools, and fast-food restaurants each played an important role in empty calorie intake among US children during 2009-2010.

    PubMed

    Poti, Jennifer M; Slining, Meghan M; Popkin, Barry M

    2014-06-01

    Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast-food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2 to 18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast-food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar-sweetened beverages, grain desserts, and high-fat milk∗ from stores; high-fat milk, grain desserts, and pizza from schools; and sugar-sweetened beverages, dairy desserts, french fries, and pizza from fast-food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. These findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast-food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to implementation of these changes, schools resembled fast-food restaurants in their contributions to empty calorie intake.

  13. Where are kids getting their empty calories? Stores, schools, and fast food restaurants each play an important role in empty calorie intake among US children in 2009-2010

    PubMed Central

    Poti, Jennifer M.; Slining, Meghan M.; Popkin, Barry M.; Kenan, W.R.

    2013-01-01

    Consumption of empty calories, the sum of energy from added sugar and solid fat, exceeds recommendations, but little is known about where US children obtain these empty calories. The objectives of this study were to compare children's empty calorie consumption from retail food stores, schools, and fast food restaurants; to identify food groups that were top contributors of empty calories from each location; and to determine the location providing the majority of calories for these key food groups. This cross-sectional analysis used data from 3,077 US children aged 2-18 years participating in the 2009-2010 National Health and Nutrition Examination Survey. The empty calorie content of children's intake from stores (33%), schools (32%), and fast food restaurants (35%) was not significantly different in 2009-2010. In absolute terms, stores provided the majority of empty calorie intake (436 kcal). The top contributors of added sugar and solid fat from each location were similar: sugar sweetened beverages (SSBs), grain desserts, and high-fat milk from stores; high-fat milk, grain desserts, and pizza from schools; and SSBs, dairy desserts, french fries, and pizza from fast food restaurants. Schools contributed about 20% of children's intake of high-fat milk and pizza. In conclusion, these findings support the need for continued efforts to reduce empty calorie intake among US children aimed not just at fast food restaurants, but also at stores and schools. The importance of reformed school nutrition standards was suggested, as prior to their implementation, schools resembled fast food restaurants in their contributions to empty calorie intake. PMID:24200654

  14. Play Orientation in Physics Education.

    ERIC Educational Resources Information Center

    Von Aufshnaiter, Stefan; Schwedes, Hannelore

    1989-01-01

    Described is a curriculum project developed in Germany. The importance of playing and gaming for the acquisition of cognitive and social capacities, the relationships among acting, reasoning, and learning in physics instruction, and the spheres of subjective experience are discussed. The framework and evaluation of the curriculum are outlined. (YP)

  15. Fort Play Children Recreate Recess

    ERIC Educational Resources Information Center

    Powell, Mark

    2007-01-01

    Recess beckons well before it actually arrives. Its allure can be heard in children's lunchtime conversations as they discuss imaginary roles, plans, alliances and teams, with an obvious appetite for play and its unbounded possibility. For some children, recess provides the most important reasons to come to school. In team sports, games of chase…

  16. [Present possibilities of age determination in forensic medicine with emphasis on the importance of measurement of D- and L- forms of aspartic acid. I. An overview].

    PubMed

    Pilin, A; Pudil, F; Gross, R; Herrmannová, M

    1997-02-01

    Evaluation of age of unknown deceased persons belongs to the most important ways to identification. For the time being, morphological methods are used, namely evaluation of age according to Gustafson's method from tooth grindings or by macroscopical estimation of abrasion, transparency of root dentine, alveolar atrophy and number of missing teeth. Evaluation of the data can be influenced by an individual failure and experience showed an age related decrease of precision. Recently, some papers occurred estimating a relation of D, L-forms of aspartic acid which depends on the age with a significant precision.

  17. Return to Play

    ERIC Educational Resources Information Center

    Mangan, Marianne

    2013-01-01

    Call it physical activity, call it games, or call it play. Whatever its name, it's a place we all need to return to. In the physical education, recreation, and dance professions, we need to redesign programs to address the need for and want of play that is inherent in all of us.

  18. The Fear of Play

    ERIC Educational Resources Information Center

    Almon, Joan

    2009-01-01

    Real play--play that is initiated and directed by children and that bubbles up from within the child rather than being imposed by adults--has largely disappeared from the landscape of childhood in the United States. There are many reasons for this, such as the long hours spent in front of screens each day or in activities organized by adults. In…

  19. Clinical Intuition at Play

    ERIC Educational Resources Information Center

    Marks-Tarlow, Terry

    2014-01-01

    A clinical psychologist and consulting psychotherapist discusses how elements of play, inherent in the intuition required in analysis, can provide a cornerstone for serious therapeutic work. She argues that many aspects of play--its key roles in human development, individual growth, and personal creativity, among others--can help therapists and…

  20. Play, Policy & Practice.

    ERIC Educational Resources Information Center

    Klugman, Edgar, Ed.

    In 1992, the U.S.-Israel Binational Science Foundation (BSF), in conjunction with Wheelock College (Boston), sponsored its second workshop on children's play, entitled "Play and Cognitive Ability: The Cultural Context." This volume reflects the presentations and discussions held at the workshop, offering perspectives on children's play…

  1. An Invitation to Play.

    ERIC Educational Resources Information Center

    Lange, Jenny; Zieher, Connie

    The manual is intended to provide suggestions for play to parents of young children with exceptional educational needs. Nineteen types of activities are described and pictured, including make believe with boxes, dress-up activities, kitchen play, bubbles, small motor activities using beans and buttons, use of throw-away materials, painting,…

  2. Role Playing and Skits

    ERIC Educational Resources Information Center

    Letwin, Robert, Ed.

    1975-01-01

    Explores non-scripted role playing, dialogue role playing, sociodrama, and skits as variations of simulation techniques. Provides step-by-step guidelines for conducting such sessions. Successful Meetings, Bill Communications, Inc., 1422 Chestnut Street, Philadelphia, Pa. 19102. Subscription Rates: yearly (US, Canada, Mexico) $14.00; elsewhere,…

  3. Theories of Play.

    ERIC Educational Resources Information Center

    Peller, Lili E.

    1996-01-01

    Discusses several theories of play advanced before the development of psychoanalysis, including the theories of surplus energy, recreation, and practice. Examines the psychoanalytical view advanced by Freud and others, which focuses on the emotional release of play and its role in discovery and learning. (MDM)

  4. Play and Digital Media

    ERIC Educational Resources Information Center

    Johnson, James E.; Christie, James F.

    2009-01-01

    This article examines how play is affected by computers and digital toys. Research indicates that when computer software targeted at children is problem-solving oriented and open-ended, children tend to engage in creative play and interact with peers in a positive manner. On the other hand, drill-and-practice programs can be quite boring and limit…

  5. Let's Just Play

    ERIC Educational Resources Information Center

    Schmidt, Janet

    2003-01-01

    Children have a right to play. The idea is so simple it seems self-evident. But a stroll through any toy superstore, or any half-hour of so-called "children's" programming on commercial TV, makes it clear that violence, not play, dominates what's being sold. In this article, the author discusses how teachers and parents share the responsibility in…

  6. Play, Toys and Television.

    ERIC Educational Resources Information Center

    Brougere, Gilles

    In Western societies, television has transformed the life, culture, and points of reference of the child. Its particular sphere of influence is the child's play culture. This play culture is not hermetic: it is very oriented toward manipulation; has a symbolic role as a representational medium; evolves along with the child; has a certain amount of…

  7. Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India.

    NASA Astrophysics Data System (ADS)

    Sharma, Disha; Kulshrestha, Umesh

    Airborne soil dust and its importance in buffering of atmospheric acidity and critical load assessment, over the semi arid tract of northern India. The Critical Load approach alongwith integrated assessment models has been used in the European nations for policy formations to reduce acidic emissions. This unique approach was applied to assess the of vulnerability of natural systems to the present day atmospheric pollution scenario. The calculated values of critical loads of sulphur ( 225 - 275 eq/ha/yr) and nitrogen (298 - 303 eq/ha/yr), for the soil system in Delhi, were calculated with respect to Anjan grass, Hibiscus and Black siris. The present loads of sulphur (PL(S) = 26.40 eq/ha/yr) and nitrogen (PL(N) = 36.51 eq/ha/yr) were found to be much lower than their critical loads without posing any danger of atmospheric acidic deposition on the soil systems. The study indicated that the system is still protective due to high pH of soil. The nature of buffering capability of calcium derived from soil dust can be considered as a natural tool to combat acidification in the Indian region. The results showed that the pollution status in Delhi is still within the safe limits. However, at the pace at which the city is growing, it is likely that in coming decades, it may exceed these critical values. In order to set deposition limits and avoid adverse effects of acidic deposition this approach can be applied in India too. Such approach is very useful, not only in abating pollution but also in devising means of cost optimal emission abatement strategies.

  8. [Amino acids 395-416 in DNA binding domain of STAT4 is involved in IL-12-induced nuclear import of STAT4].

    PubMed

    Huang, Yu-Mei; Wen, Ya-Ping; Li, Xuan-An; Yuan, Yuan; Luo, Qi-Zhi; Li, Ming

    2012-08-25

    The purpose of the present study is to explore the mechanism of IL-12-induced nuclear import of signal transducer and activator of transcription 4 (STAT4). Assayed by analyses of homology alignment of STATs, amino acids 395-416 in DNA binding domain was found to be a potential dimer-specific nuclear localization signal (dsNLS) of STAT4. Therefore, several plasmids were constructed. Wild-type STAT4 was inserted into the SalI and BamHI sites of pEGFP-C1 for the construction of plasmid pEGFP-STAT4. The DNA fragment of STAT4 with the deletion of amino acids 395-416 was amplified by RCR and introduced into the SalI and BamHI sites of pEGFP-C1 which was named pEGFP-STAT4-Del. Classic NLS DNA sequence of SV40 T antigen was inserted into the XhoI and HindIII sites of pEGFP-C1. This plasmid was named as pEGFP-NLS and used as a positive control. Plasmid pEGFP-NLS-STAT4-Del was constructed by inserting STAT4-Del into SalI and BamHI sites of pEGFP-NLS. These plasmids were transiently transfected into Caski cells, respectively. The results showed that, after these transfected cells were stimulated by IL-12, wild type STAT4 existed in the cytoplasm at 0 min, and was predominantly localized to the nucleus at 45 min, and distributed in both cytoplasm and nucleus at 60 min, suggesting that STAT4 translocates from cytoplasm into nucleus and finally re-entries into the cytoplasm during the stimulation of IL-12. However, deletion mutant of STAT4 was arrested in cytoplasm during the IL-12 stimulation. Leptomycin B, which specifically blocks protein export from nucleus into cytoplasm, was used to further demonstrate whether STAT4-Del is transferred into nucleus even with stimulation of IL-12. After the transfected cells were pre-treated by leptomycin B, the wild type STAT4 was mainly localized in nucleus after the IL-12 stimulation, suggesting that STAT4 was translocated from cytoplasm into nucleus by the stimulation of IL-12. On the other hand, the deletion mutant of STAT4 distributed

  9. Playing Fair: An Essential Element in Contracting

    ERIC Educational Resources Information Center

    Peeler, Tom

    2012-01-01

    Playing fair has a value with which people are all familiar. From the sandboxes of childhood and the competitive sports of youth to the business transactions of adulthood, people have been told how important it is to play fair. Playing fair in contracting is not only essential, it's the legal and ethical thing to do. In this article, the author…

  10. Amino acid residues 1101-1105 of the isotypic region of human C4B is important to the covalent binding activity of complement component C4.

    PubMed

    Reilly, B D; Levine, R P; Skanes, V M

    1991-11-01

    The C4A and C4B isotypes of human C4 show certain functional differences that stem from their relative preference for transacylation to amino (-NH2) vs hydroxyl (-OH) nucleophiles, respectively, on complement-activating surfaces. Comparison of amino acid sequences of the alpha-chain fragment of C4, C4d, has shown C4A- and C4B-specific sequences at residues 1101-1106 are the only consistent structural difference between isotype, i.e., Pro, Cys, Pro, Val, Leu, Asp in C4A and Leu, Ser, Pro, Val Ile, His in C4B. These residues may be responsible either in part or entirely for properties associated with isotype. To examine the functional role of residues 1101-1106 in C4B-mediated hemolysis, whole serum or immunopurified human C4 with allotypes, A3B1, A3, B2B1, or B1 were preincubated in the presence or absence of an antipeptide mAb (BII-1) specific for amino acid residues 1101-1105 of C4B. Sensitized sheep E and C4-deficient guinea pig serum was then added and lysis measured by absorbance at 415 nm. Our results show lysis of antibody-sensitized sheep E is inhibited by antibody and C4B2B1, C4B1, or C4A3B1 but not antibody and C4A3. The interference of hemolysis by BII-1 could not be explained by inhibition of activation of C4B or inhibition of C3 or C5 convertase activity. Furthermore, results from uptake experiments show that BII-1 interferes with the covalent binding activity of C4B, indicating residues 1101-1105 play a role in the covalent binding reaction of C4B to the target E-antibody complex.

  11. The Scottish Play.

    ERIC Educational Resources Information Center

    Wheat, Chris

    1999-01-01

    Recounts an episode when, as young schoolboys, Prince Charles and classmates presented "Macbeth" as an end-of-term-play. Traces the events at school that took on different meanings when viewed from maturity. (NH)

  12. Global expression pattern comparison between low phosphorus insensitive 4 and WT Arabidopsis reveals an important role of reactive oxygen species and jasmonic acid in the root tip response to phosphate starvation.

    PubMed

    Chacón-López, Alejandra; Ibarra-Laclette, Enrique; Sánchez-Calderón, Lenin; Gutiérrez-Alanis, Dolores; Herrera-Estrella, Luis

    2011-03-01

    Plants are exposed to several biotic and abiotic stresses. A common environmental stress that plants have to face both in natural and agricultural ecosystems that impacts both its growth and development is low phosphate (Pi) availability. There has been an important progress in the knowledge of the molecular mechanisms by which plants cope with Pi deficiency. However, the mechanisms that mediate alterations in the architecture of the Arabidopsis root system responses to Pi starvation are still largely unknown. One of the most conspicuous developmental effects of low Pi on the Arabidopsis root system is the inhibition of primary root growth that is accompanied by loss of root meristematic activity. To identify signalling pathways potentially involved in the Arabidpsis root meristem response to Pi-deprivation, here we report the global gene expression analysis of the root tip of wild type and low phosphorus insensitive4 (lpi4) mutant grown under Pi limiting conditions. Differential gene expression analysis and physiological experiments show that changes in the redox status, probably mediated by jasmonic acid and ethylene, play an important role in the primary root meristem exhaustion process triggered by Pi-starvation.

  13. Substrate selectivity of human cytochrome P450 2C9: importance of residues 476, 365, and 114 in recognition of diclofenac and sulfaphenazole and in mechanism-based inactivation by tienilic acid.

    PubMed

    Melet, Armelle; Assrir, Nadine; Jean, Pascale; Pilar Lopez-Garcia, Maria; Marques-Soares, Cristina; Jaouen, Maryse; Dansette, Patrick M; Sari, Marie Agnès; Mansuy, Daniel

    2003-01-01

    A series of six site-directed mutants of CYP 2C9 were constructed with the aim to better define the amino acid residues that play a critical role in substrate selectivity of CYP 2C9, particularly in three distinctive properties of this enzyme: (i) its selective mechanism-based inactivation by tienilic acid (TA), (ii) its high affinity and hydroxylation regioselectivity toward diclofenac, and (iii) its high affinity for the competitive inhibitor sulfaphenazole (SPA). The S365A mutant exhibited kinetic characteristics for the 5-hydroxylation of TA very similar to those of CYP 2C9; however, this mutant did not undergo any detectable mechanism-based inactivation by TA, which indicates that the OH group of Ser 365 could be the nucleophile forming a covalent bond with an electrophilic metabolite of TA in TA-dependent inactivation of CYP 2C9. The F114I mutant was inactive toward the hydroxylation of diclofenac; moreover, detailed analyses of its interaction with a series of SPA derivatives by difference visible spectroscopy showed that the high affinity of SPA to CYP 2C9 (K(s)=0.4 microM) was completely lost when the phenyl substituent of Phe 114 was replaced with the alkyl group of Ile (K(s)=190+/-20 microM), or when the phenyl substituent of SPA was replaced with a cyclohexyl group (K(s)=120+/-30 microM). However, this cyclohexyl derivative of SPA interacted well with the F114I mutant (K(s)=1.6+/-0.5 microM). At the opposite end, the F94L and F110I mutants showed properties very similar to those of CYP 2C9 toward TA and diclofenac. Finally, the F476I mutant exhibited at least three main differences compared to CYP 2C9: (i) big changes in the k(cat) and K(m) values for TA and diclofenac hydroxylation, (ii) a 37-fold increase of the K(i) value found for the inhibition of CYP 2C9 by SPA, and (iii) a great change in the regioselectivity of diclofenac hydroxylation, the 5-hydroxylation of this substrate by CYP 2C9 F476I exhibiting a k(cat) of 28min(-1). These data indicate

  14. Characterization of hepatitis C virus recombinants with chimeric E1/E2 envelope proteins and identification of single amino acids in the E2 stem region important for entry.

    PubMed

    Carlsen, Thomas H R; Scheel, Troels K H; Ramirez, Santseharay; Foung, Steven K H; Bukh, Jens

    2013-02-01

    The hepatitis C virus (HCV) envelope proteins E1 and E2 play a key role in host cell entry and represent important targets for vaccine and drug development. Here, we characterized HCV recombinants with chimeric E1/E2 complexes in vitro. Using genotype 1a/2a JFH1-based recombinants expressing 1a core-NS2, we exchanged E2 with functional isolate sequences of genotypes 1a (alternative isolate), 1b, and 2a. While the 1a-E2 exchange did not impact virus viability, the 2a-E2 recombinant was nonviable. After E2 exchange from three 1b isolates, long delays were observed before spread of infection. For recovered 1b-E2 recombinants, single E2 stem region amino acid changes were identified at residues 706, 707, and 710. In reverse genetic studies, these mutations increased infectivity titers by ~100-fold, apparently without influencing particle stability or cell binding although introducing slight decrease in particle density. In addition, the 1b-E2 exchange led to a decrease in secreted core protein of 25 to 50%, which was further reduced by the E2 stem region mutations. These findings indicated that compensatory mutations permitted robust infectious virus production, without increasing assembly/release. Studies of E1/E2 heterodimerization showed no differences in intracellular E1/E2 interaction for chimeric constructs with or without E2 stem region mutations. Interestingly, the E2 stem region mutations allowed efficient entry, which was verified in 1a-E1/1b-E2 HCV pseudoparticle assays. A CD81 inhibition assay indicated that the mutations influenced a late step of the HCV entry pathway. Overall, this study identified specific amino acids in the E2 stem region of importance for HCV entry and for production of infectious virus particles.

  15. Aspartate oxidase plays an important role in Arabidopsis stomatal immunity.

    PubMed

    Macho, Alberto P; Boutrot, Freddy; Rathjen, John P; Zipfel, Cyril

    2012-08-01

    Perception of pathogen-associated molecular patterns (PAMPs), such as bacterial flagellin (or the peptide flg22), by surface-localized receptors activates defense responses and subsequent immunity. In a previous forward-genetic screen aimed at the identification of Arabidopsis (Arabidopsis thaliana) flagellin-insensitive (fin) mutants, we isolated fin4, which is severely affected in flg22-triggered reactive oxygen species (ROS) bursts. Here, we report that FIN4 encodes the chloroplastic enzyme ASPARTATE OXIDASE (AO), which catalyzes the first irreversible step in the de novo biosynthesis of NAD. Genetic studies on the role of NAD have been hindered so far by the lethality of null mutants in NAD biosynthetic enzymes. Using newly identified knockdown fin alleles, we found that AO is required for the ROS burst mediated by the NADPH oxidase RBOHD triggered by the perception of several unrelated PAMPs. AO is also required for RBOHD-dependent stomatal closure. However, full AO activity is not required for flg22-induced responses that are RBOHD independent. Interestingly, although the fin4 mutation dramatically affects RBOHD function, it does not affect functions carried out by other members of the RBOH family, such as RBOHC and RBOHF. Finally, we determined that AO is required for stomatal immunity against the bacterium Pseudomonas syringae. Altogether, our work reveals a novel specific requirement for AO activity in PAMP-triggered RBOHD-dependent ROS burst and stomatal immunity. In addition, the availability of viable mutants for the chloroplastic enzyme AO will enable future detailed studies on the role of NAD metabolism in different cellular processes, including immunity, in Arabidopsis.

  16. Microbial communities play important roles in modulating paddy soil fertility.

    PubMed

    Luo, Xuesong; Fu, Xiaoqian; Yang, Yun; Cai, Peng; Peng, Shaobing; Chen, Wenli; Huang, Qiaoyun

    2016-02-04

    We studied microbial communities in two paddy soils, which did not receive nitrogen fertilization and were distinguished by the soil properties. The two microbial communities differed in the relative abundance of gram-negative bacteria and total microbial biomass. Variability in microbial communities between the two fields was related to the levels of phosphorus and soil moisture. Redundancy analysis for individual soils showed that the bacterial community dynamics in the high-yield soil were significantly correlated with total carbon, moisture, available potassium, and pH, and those in the low-yield cores were shaped by pH, and nitrogen factors. Biolog Eco-plate data showed a more active microbial community in the high yield soil. The variations of enzymatic activities in the two soils were significantly explained by total nitrogen, total potassium, and moisture. The enzymatic variability in the low-yield soil was significantly explained by potassium, available nitrogen, pH, and total carbon, and that in the high-yield soil was partially explained by potassium and moisture. We found the relative abundances of Gram-negative bacteria and Actinomycetes partially explained the spatial and temporal variations of soil enzymatic activities, respectively. The high-yield soil microbes are probably more active to modulate soil fertility for rice production.

  17. Microbial communities play important roles in modulating paddy soil fertility

    NASA Astrophysics Data System (ADS)

    Luo, Xuesong; Fu, Xiaoqian; Yang, Yun; Cai, Peng; Peng, Shaobing; Chen, Wenli; Huang, Qiaoyun

    2016-02-01

    We studied microbial communities in two paddy soils, which did not receive nitrogen fertilization and were distinguished by the soil properties. The two microbial communities differed in the relative abundance of gram-negative bacteria and total microbial biomass. Variability in microbial communities between the two fields was related to the levels of phosphorus and soil moisture. Redundancy analysis for individual soils showed that the bacterial community dynamics in the high-yield soil were significantly correlated with total carbon, moisture, available potassium, and pH, and those in the low-yield cores were shaped by pH, and nitrogen factors. Biolog Eco-plate data showed a more active microbial community in the high yield soil. The variations of enzymatic activities in the two soils were significantly explained by total nitrogen, total potassium, and moisture. The enzymatic variability in the low-yield soil was significantly explained by potassium, available nitrogen, pH, and total carbon, and that in the high-yield soil was partially explained by potassium and moisture. We found the relative abundances of Gram-negative bacteria and Actinomycetes partially explained the spatial and temporal variations of soil enzymatic activities, respectively. The high-yield soil microbes are probably more active to modulate soil fertility for rice production.

  18. Ice sheets play important role in climate change

    NASA Astrophysics Data System (ADS)

    Clark, Peter U.; MacAyeal, Douglas R.; Andrews, John T.; Bartlein, Patrick J.

    Ice sheets once were viewed as passive elements in the climate system enslaved to orbitally generated variations in solar radiation. Today, modeling results and new geologic records suggest that ice sheets actively participated in late-Pleistocene climate change, amplifying or driving significant variability at millennial as well as orbital timescales. Although large changes in global ice volume were ultimately caused by orbital variations (the Milankovitch hypothesis), once in existence, the former ice sheets behaved dynamically and strongly influenced regional and perhaps even global climate by altering atmospheric and oceanic circulation and temperature.Experiments with General Circulation Models (GCMs) yielded the first inklings of ice sheets' climatic significance. Manabe and Broccoli [1985], for example, found that the topographic and albedo effects of ice sheets alone explain much of the Northern Hemisphere cooling identified in paleoclimatic records of the last glacial maximum (˜21 ka).

  19. Microbial communities play important roles in modulating paddy soil fertility

    PubMed Central

    Luo, Xuesong; Fu, Xiaoqian; Yang, Yun; Cai, Peng; Peng, Shaobing; Chen, Wenli; Huang, Qiaoyun

    2016-01-01

    We studied microbial communities in two paddy soils, which did not receive nitrogen fertilization and were distinguished by the soil properties. The two microbial communities differed in the relative abundance of gram-negative bacteria and total microbial biomass. Variability in microbial communities between the two fields was related to the levels of phosphorus and soil moisture. Redundancy analysis for individual soils showed that the bacterial community dynamics in the high-yield soil were significantly correlated with total carbon, moisture, available potassium, and pH, and those in the low-yield cores were shaped by pH, and nitrogen factors. Biolog Eco-plate data showed a more active microbial community in the high yield soil. The variations of enzymatic activities in the two soils were significantly explained by total nitrogen, total potassium, and moisture. The enzymatic variability in the low-yield soil was significantly explained by potassium, available nitrogen, pH, and total carbon, and that in the high-yield soil was partially explained by potassium and moisture. We found the relative abundances of Gram-negative bacteria and Actinomycetes partially explained the spatial and temporal variations of soil enzymatic activities, respectively. The high-yield soil microbes are probably more active to modulate soil fertility for rice production. PMID:26841839

  20. ASXL1 plays an important role in erythropoiesis

    PubMed Central

    Shi, Hui; Yamamoto, Shohei; Sheng, Mengyao; Bai, Jie; Zhang, Peng; Chen, Runze; Chen, Shi; Shi, Lihong; Abdel-Wahab, Omar; Xu, Mingjiang; Zhou, Yuan; Yang, Feng-Chun

    2016-01-01

    ASXL1 mutations are found in a spectrum of myeloid malignancies with poor prognosis. Recently, we reported that Asxl1+/− mice develop myelodysplastic syndrome (MDS) or MDS and myeloproliferative neoplasms (MPN) overlapping diseases (MDS/MPN). Although defective erythroid maturation and anemia are associated with the prognosis of patients with MDS or MDS/MPN, the role of ASXL1 in erythropoiesis remains unclear. Here, we showed that chronic myelomonocytic leukemia (CMML) patients with ASXL1 mutations exhibited more severe anemia with a significantly increased proportion of bone marrow (BM) early stage erythroblasts and reduced enucleated erythrocytes compared to CMML patients with WT ASXL1. Knockdown of ASXL1 in cord blood CD34+ cells reduced erythropoiesis and impaired erythrocyte enucleation. Consistently, the BM and spleens of VavCre+;Asxl1f/f (Asxl1∆/∆) mice had less numbers of erythroid progenitors than Asxl1f/f controls. Asxl1∆/∆ mice also had an increased percentage of erythroblasts and a reduced erythrocyte enucleation in their BM compared to littermate controls. Furthermore, Asxl1∆/∆ erythroblasts revealed altered expression of genes involved in erythroid development and homeostasis, which was associated with lower levels of H3K27me3 and H3K4me3. Our study unveils a key role for ASXL1 in erythropoiesis and indicates that ASXL1 loss hinders erythroid development/maturation, which could be of prognostic value for MDS/MPN patients. PMID:27352931

  1. Import of desired nucleic acid sequences using addressing motif of mitochondrial ribosomal 5S-rRNA for fluorescent in vivo hybridization of mitochondrial DNA and RNA.

    PubMed

    Zelenka, Jaroslav; Alán, Lukáš; Jabůrek, Martin; Ježek, Petr

    2014-04-01

    Based on the matrix-addressing sequence of mitochondrial ribosomal 5S-rRNA (termed MAM), which is naturally imported into mitochondria, we have constructed an import system for in vivo targeting of mitochondrial DNA (mtDNA) or mt-mRNA, in order to provide fluorescence hybridization of the desired sequences. Thus DNA oligonucleotides were constructed, containing the 5'-flanked T7 RNA polymerase promoter. After in vitro transcription and fluorescent labeling with Alexa Fluor(®) 488 or 647 dye, we obtained the fluorescent "L-ND5 probe" containing MAM and exemplar cargo, i.e., annealing sequence to a short portion of ND5 mRNA and to the light-strand mtDNA complementary to the heavy strand nd5 mt gene (5'-end 21 base pair sequence). For mitochondrial in vivo fluorescent hybridization, HepG2 cells were treated with dequalinium micelles, containing the fluorescent probes, bringing the probes proximally to the mitochondrial outer membrane and to the natural import system. A verification of import into the mitochondrial matrix of cultured HepG2 cells was provided by confocal microscopy colocalizations. Transfections using lipofectamine or probes without 5S-rRNA addressing MAM sequence or with MAM only were ineffective. Alternatively, the same DNA oligonucleotides with 5'-CACC overhang (substituting T7 promoter) were transcribed from the tetracycline-inducible pENTRH1/TO vector in human embryonic kidney T-REx®-293 cells, while mitochondrial matrix localization after import of the resulting unlabeled RNA was detected by PCR. The MAM-containing probe was then enriched by three-order of magnitude over the natural ND5 mRNA in the mitochondrial matrix. In conclusion, we present a proof-of-principle for mitochondrial in vivo hybridization and mitochondrial nucleic acid import.

  2. Functionally important amino acid residues in the transient receptor potential vanilloid 1 (TRPV1) ion channel – an overview of the current mutational data

    PubMed Central

    2013-01-01

    This review aims to create an overview of the currently available results of site-directed mutagenesis studies on transient receptor potential vanilloid type 1 (TRPV1) receptor. Systematization of the vast number of data on the functionally important amino acid mutations of TRPV1 may provide a clearer picture of this field, and may promote a better understanding of the relationship between the structure and function of TRPV1. The review summarizes information on 112 unique mutated sites along the TRPV1, exchanged to multiple different residues in many cases. These mutations influence the effect or binding of different agonists, antagonists, and channel blockers, alter the responsiveness to heat, acid, and voltage dependence, affect the channel pore characteristics, and influence the regulation of the receptor function by phosphorylation, glycosylation, calmodulin, PIP2, ATP, and lipid binding. The main goal of this paper is to publish the above mentioned data in a form that facilitates in silico molecular modelling of the receptor by promoting easier establishment of boundary conditions. The better understanding of the structure-function relationship of TRPV1 may promote discovery of new, promising, more effective and safe drugs for treatment of neurogenic inflammation and pain-related diseases and may offer new opportunities for therapeutic interventions. PMID:23800232

  3. Importance of a specific amino acid pairing for murine MLL leukemias driven by MLLT1/3 or AFF1/4.

    PubMed

    Lokken, Alyson A; Achille, Nicholas J; Chang, Ming-Jin; Lin, Jeffrey J; Kuntimaddi, Aravinda; Leach, Benjamin I; Malik, Bhavna; Nesbit, Jacqueline B; Zhang, Shubin; Bushweller, John H; Zeleznik-Le, Nancy J; Hemenway, Charles S

    2014-11-01

    Acute leukemias caused by translocations of the MLL gene at chromosome 11 band q23 (11q23) are characterized by a unique gene expression profile. More recently, data from several laboratories indicate that the most commonly encountered MLL fusion proteins, MLLT1, MLLT3, and AFF1 are found within a molecular complex that facilitates the elongation phase of mRNA transcription. Mutational analyses suggest that interaction between the MLLT1/3 proteins and AFF family proteins are required for experimental transformation of hematopoietic progenitor cells (HPCs). Here, we define a specific pairing of two amino acids that creates a salt bridge between MLLT1/3 and AFF proteins that is critically important for MLL-mediated transformation of HPCs. Our findings, coupled with the newly defined structure of MLLT3 in complex with AFF1, should facilitate the development of small molecules that block this amino acid interaction and interfere with the activity of the most common MLL oncoproteins.

  4. Current topics in the biotechnological production of essential amino acids, functional amino acids, and dipeptides.

    PubMed

    Mitsuhashi, Satoshi

    2014-04-01

    Amino acids play important roles in both human and animal nutrition and in the maintenance of health. Here, amino acids are classified into three groups: first, essential amino acids, which are essential to nutrition; second, functional amino acids, recently found to be important in the promotion of physiological functions; and third, dipeptides, which are used to resolve problematic features of specific free amino acids, such as their instability or insolubility. This review focusses on recent researches concerning the microbial production of essential amino acids (lysine and methionine), functional amino acids (histidine and ornithine), and a dipeptide (L-alanyl-L-glutamine).

  5. A theoretical investigation of the atmospherically important reaction between chlorine atoms and formic acid: determination of the reaction mechanism and calculation of the rate coefficient at different temperatures

    NASA Astrophysics Data System (ADS)

    Ng, Maggie; Mok, Daniel K. W.; Lee, Edmond P. F.; Dyke, John M.

    2015-07-01

    The Cl + HCOOH reaction is important in the atmosphere, as the chlorine (Cl) atom is an important oxidant, especially in the marine boundary layer, and formic acid (HCOOH) is one of the most abundant organic acids in the troposphere. The reaction surfaces of the two H abstraction channels were computed by second-order unrestricted Møller-Plesset perturbation theory (UMP2) and density functional theory (DFT) calculations. Relative electronic energies were improved to the RCCSD(T)/CBS and UCCSD(T)-F12/CBS levels. The barrier of the C-H hydrogen abstraction channel was found to be lower by about 10 kcal mol-1. Rate coefficients (k) of this channel were calculated at different temperatures at various variational transition state theory (VTST) levels including tunnelling. For single-level direct dynamics VTST calculations, the computed k (2.5 × 10-13 cm3 molecule-1 s-1) using the BMK (Boese and Martin meta hybrid) functional at the highest level (ICVT/SCT) agrees the best with experimental values at 298 K (1.8 and 2.0 × 10-13 cm3 molecule-1 s-1). For dual-level direct dynamics calculations (RCCSD(T)/CBS//MP2 MEP), an adjusted barrier height of 3.1 kcal mol-1 is required to match the ICVT/SCT k with the experimental values. The computed rate coefficients of the Cl + HCOOH reaction is reported for the first time with a temperature range of 200-1500 K. The implications of the results obtained to atmospheric chemistry are discussed.

  6. Conserved Amino Acid Residues of the NuoD Segment Important for Structure and Function of Escherichia coli NDH-1 (Complex I)

    PubMed Central

    2015-01-01

    The NuoD segment (homologue of mitochondrial 49 kDa subunit) of the proton-translocating NADH:quinone oxidoreductase (complex I/NDH-1) from Escherichia coli is in the hydrophilic domain and bears many highly conserved amino acid residues. The three-dimensional structural model of NDH-1 suggests that the NuoD segment, together with the neighboring subunits, constitutes a putative quinone binding cavity. We used the homologous DNA recombination technique to clarify the role of selected key amino acid residues of the NuoD segment. Among them, residues Tyr273 and His224 were considered candidates for having important interactions with the quinone headgroup. Mutant Y273F retained partial activity but lost sensitivity to capsaicin-40. Mutant H224R scarcely affected the activity, suggesting that this residue may not be essential. His224 is located in a loop near the N-terminus of the NuoD segment (Gly217–Phe227) which is considered to form part of the quinone binding cavity. In contrast to the His224 mutation, mutants G217V, P218A, and G225V almost completely lost the activity. One region of this loop is positioned close to a cytosolic loop of the NuoA subunit in the membrane domain, and together they seem to be important in keeping the quinone binding cavity intact. The structural role of the longest helix in the NuoD segment located behind the quinone binding cavity was also investigated. Possible roles of other highly conserved residues of the NuoD segment are discussed. PMID:25545070

  7. A Specific Structural Requirement for Ergosterol in Long-chain Fatty Acid Synthesis Mutants Important for Maintaining Raft Domains in Yeast

    PubMed Central

    Eisenkolb, Marlis; Zenzmaier, Christoph; Leitner, Erich; Schneiter, Roger

    2002-01-01

    Fungal sphingolipids contain ceramide with a very-long-chain fatty acid (C26). To investigate the physiological significance of the C26-substitution on this lipid, we performed a screen for mutants that are synthetically lethal with ELO3. Elo3p is a component of the ER-associated fatty acid elongase and is required for the final elongation cycle to produce C26 from C22/C24 fatty acids. elo3Δ mutant cells thus contain C22/C24- instead of the natural C26-substituted ceramide. We now report that under these conditions, an otherwise nonessential, but also fungal-specific, structural modification of the major sterol of yeast, ergosterol, becomes essential, because mutations in ELO3 are synthetically lethal with mutations in ERG6. Erg6p catalyzes the methylation of carbon atom 24 in the aliphatic side chain of sterol. The lethality of an elo3Δ erg6Δ double mutant is rescued by supplementation with ergosterol but not with cholesterol, indicating a vital structural requirement for the ergosterol-specific methyl group. To characterize this structural requirement in more detail, we generated a strain that is temperature sensitive for the function of Erg6p in an elo3Δ mutant background. Examination of raft association of the GPI-anchored Gas1p and plasma membrane ATPase, Pma1p, in the conditional elo3Δ erg6ts double mutant, revealed a specific defect of the mutant to maintain raft association of preexisting Pma1p. Interestingly, in an elo3Δ mutant at 37°C, newly synthesized Pma1p failed to enter raft domains early in the biosynthetic pathway, and upon arrival at the plasma membrane was rerouted to the vacuole for degradation. These observations indicate that the C26 fatty acid substitution on lipids is important for establishing raft association of Pma1p and stabilizing the protein at the cell surface. Analysis of raft lipids in the conditional mutant strain revealed a selective enrichment of ergosterol in detergent-resistant membrane domains, indicating that specific

  8. Creative Outdoor Play Areas.

    ERIC Educational Resources Information Center

    Miller, Peggy L.

    Considering the creation of proper play areas for children (school sites, municipal and mini parks, private homes and backyards, shopping centers, apartment complexes, recreational areas, roadside parks, nursery schools, churches, summer camps, and drive-in theaters) as one of today's major challenges, the author recommends that professional…

  9. Playing with Science

    ERIC Educational Resources Information Center

    Vieyra, Rebecca; Edwards, Teon; Rowe, Elizabeth; Asbell-Clarke, Jodi

    2015-01-01

    Gaming is becoming an effective form of learning and assessment and shouldn't be overlooked in an increasingly technological world. The games described in this article ("Impulse," "Quantum Spectre," and "Ravenous"), entertaining enough to be played by the general public, are also appropriate and useful in a classroom…

  10. "Playing" with Science

    ERIC Educational Resources Information Center

    Allen, Dave

    2012-01-01

    When faced with a multitude of tasks, any opportunity to "kill two birds with one stone" is welcome. Drama has always excited the author: as a child performing in plays, later as a student and now as a teacher directing performances and improvising within lessons. The author was lucky enough to have inspirational teachers during his…

  11. Integrated Play Groups

    ERIC Educational Resources Information Center

    Glovak, Sandra

    2007-01-01

    As an occupational therapist running social play groups with sensory integration for children on the autism spectrum, the author frequently doubted the wisdom of combining several children on the spectrum into a group. In fact, as the owner of a clinic she said, "No more!" The groups seemed like a waste of parents' time and money, and she refused…

  12. Abstraction through Game Play

    ERIC Educational Resources Information Center

    Avraamidou, Antri; Monaghan, John; Walker, Aisha

    2012-01-01

    This paper examines the computer game play of an 11-year-old boy. In the course of building a virtual house he developed and used, without assistance, an artefact and an accompanying strategy to ensure that his house was symmetric. We argue that the creation and use of this artefact-strategy is a mathematical abstraction. The discussion…

  13. One Play a Day

    ERIC Educational Resources Information Center

    Blankenship, Mark

    2007-01-01

    Undergraduate theater students rarely get the chance to work on a major world premiere, but this year hundreds of them will. Currently, more than 70 colleges and universities are participating in "365 Days/365 Plays," an ambitious project from Pulitzer Prize-winning playwright Suzan-Lori Parks. Every week, as they mount their portion of this epic…

  14. Histidine and Aspartic Acid Residues Important for Immunoglobulin G Endopeptidase Activity of the Group A Streptococcus Opsonophagocytosis-Inhibiting Mac Protein

    PubMed Central

    Lei, Benfang; Liu, Mengyao; Meyers, Elishia G.; Manning, Heather M.; Nagiec, Michael J.; Musser, James M.

    2003-01-01

    The secreted Mac protein made by serotype M1 group A Streptococcus (GAS) (designated Mac5005) inhibits opsonophagocytosis and killing of GAS by human polymorphonuclear neutrophils. This protein also has cysteine endopeptidase activity against human immunoglobulin G (IgG). Site-directed mutagenesis was used to identify histidine and aspartic acid residues important for Mac IgG endopeptidase activity. Replacement of His262 with Ala abolished Mac5005 IgG endopeptidase activity. Asp284Ala and Asp286Ala mutant proteins had compromised enzymatic activity, whereas 21 other Asp-to-Ala mutant proteins cleaved human IgG at the apparent wild-type level. The results suggest that His262 is an active-site residue and that Asp284 and Asp286 are important for the enzymatic activity or structure of Mac protein. These Mac mutants provide new information about structure-activity relationships in this protein and will assist study of the mechanism of inhibition of opsonophagocytosis and killing of GAS by Mac. PMID:12704162

  15. A Carbonic Anhydrase Serves as an Important Acid-Base Regulator in Pacific Oyster Crassostrea gigas Exposed to Elevated CO2: Implication for Physiological Responses of Mollusk to Ocean Acidification.

    PubMed

    Wang, Xiudan; Wang, Mengqiang; Jia, Zhihao; Qiu, Limei; Wang, Lingling; Zhang, Anguo; Song, Linsheng

    2017-02-01

    Carbonic anhydrases (CAs) have been demonstrated to play an important role in acid-base regulation in vertebrates. However, the classification and modulatory function of CAs in marine invertebrates, especially their responses to ocean acidification remain largely unknown. Here, a cytosolic α-CA (designated as CgCAII-1) was characterized from Pacific oyster Crassostrea gigas and its molecular activities against CO2 exposure were investigated. CgCAII-1 possessed a conserved CA catalytic domain, with high similarity to invertebrate cytoplasmic or mitochondrial α-CAs. Recombinant CgCAII-1 could convert CO2 to HCO3(-) with calculated activity as 0.54 × 10(3) U/mg, which could be inhibited by acetazolamide (AZ). The mRNA transcripts of CgCAII-1 in muscle, mantle, hepatopancreas, gill, and hemocytes increased significantly after exposure to elevated CO2. CgCAII-1 could interact with the hemocyte membrane proteins and the distribution of CgCAII-1 protein became more concentrated and dense in gill and mantle under CO2 exposure. The intracellular pH (pHi) of hemocytes under CO2 exposure increased significantly (p < 0.05) and CA inhibition reduced the pHi value. Besides, there was no increase in CA activity in gill and mantle after CO2 exposure. The impact of CO2 exposure on CA activity coupled with the mRNA expression level and protein translocation of CgCAII-1 provided evidences that CgCAII-1 could respond to ocean acidification and participate in acid-base regulation. Such cytoplasmic CA-based physiological regulation mechanism might explain other physiological responses of marine organisms to OA.

  16. Importance of direct anthropogenic emissions of formic acid measured by a chemical ionisation mass spectrometer (CIMS) during the Winter ClearfLo Campaign in London, January 2012

    NASA Astrophysics Data System (ADS)

    Bannan, Thomas J.; Bacak, Asan; Muller, Jennifer B. A.; Booth, A. Murray; Jones, Benjamin; Le Breton, Michael; Leather, Kimberley E.; Ghalaieny, Mohamed; Xiao, Ping; Shallcross, Dudley E.; Percival, Carl J.

    2014-02-01

    Formic acid, an ubiquitous trace gas in the atmosphere, was measured using a chemical ionisation mass spectrometer (CIMS) during the winter ClearfLo campaign in London, 2012. Daily calibrations of formic acid gave sensitivities of 3 ion counts s-1 pptv-1 for the complete campaign and a limit of detection of 2 ppt. No correlation with nitric acid was observed, R2 of 0.137, indicating no significant secondary source of formic acid. However, a strong positive correlation with NOx, CO, and production in line with rush hour periods indicated a direct anthropogenic emission of formic acid from vehicle emissions. Peaks of 6.7 ppb of formic acid were observed with a mean of 610 ppt. Global models indicated that this emission source dominates in the northern hemisphere where global models underestimate formic acid most significantly, thus increasing the accuracy of modelling of global formic acid emissions.

  17. Solar Power at Play

    NASA Astrophysics Data System (ADS)

    2007-03-01

    For the very first time, astronomers have witnessed the speeding up of an asteroid's rotation, and have shown that it is due to a theoretical effect predicted but never seen before. The international team of scientists used an armada of telescopes to discover that the asteroid's rotation period currently decreases by 1 millisecond every year, as a consequence of the heating of the asteroid's surface by the Sun. Eventually it may spin faster than any known asteroid in the solar system and even break apart. ESO PR Photo 11a/07 ESO PR Photo 11a/07 Asteroid 2000 PH5 "The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is believed to alter the way small bodies in the Solar System rotate," said Stephen Lowry (Queens University Belfast, UK), lead-author of one of the two companion papers in which this work is reported [1, 2]. "The warming caused by sunlight hitting the surfaces of asteroids and meteoroids leads to a gentle recoil effect as the heat is released," he added. "By analogy, if one were to shine light on a propeller over a long enough period, it would start spinning." Although this is an almost immeasurably weak force, its effect over millions of years is far from negligible. Astronomers believe the YORP effect may be responsible for spinning some asteroids up so fast that they break apart, perhaps leading to the formation of double asteroids. Others may be slowed down so that they take many days to complete a full turn. The YORP effect also plays an important role in changing the orbits of asteroids between Mars and Jupiter, including their delivery to planet-crossing orbits, such as those of near-Earth asteroids. Despite its importance, the effect has never been seen acting on a solar system body, until now. Using extensive optical and radar imaging from powerful Earth-based observatories, astronomers have directly observed the YORP effect in action on a small near-Earth asteroid, known as (54509) 2000 PH5. Shortly after its discovery in 2000, it was