PHD Domain-Mediated E3 Ligase Activity Directs Intramolecular Sumoylation of an Adjacent Bromodomain which is Required for Gene Silencing

PubMed Central

Ivanov, Alexey V.; Peng, Hongzhuang; Yurchenko, Vyacheslav; Yap, Kyoko L.; Negorev, Dmitri G.; Schultz, David C.; Psulkowski, Elyse; Fredericks, William J.; White, David E.; Maul, Gerd G.; Sadofsky, Moshe J.; Zhou, Ming-Ming; Rauscher, Frank J.

2015-01-01

SUMMARY Tandem PHD and bromodomains are often found in chromatin-associated proteins and have been shown to cooperate in gene silencing. Each domain can bind specifically modified histones: the mechanisms of cooperation between these domains are unknown. We show that the PHD domain of the KAP1 corepressor functions as an intramolecular E3 ligase for sumoylation of the adjacent bromodomain. The RING finger-like structure of the PHD domain is required for both Ubc9 binding and sumoylation and directs modification to specific lysine residues in the bromodomain. Sumoylation is required for KAP1-mediated gene silencing and functions by directly recruiting the SETDB1 histone methyltransferase and the CHD3/Mi2 component of the NuRD complex via SUMO interacting motifs. Sumoylated KAP1 stimulates the histone methyltransferase activity of SETDB1. These data provide a mechanistic explanation for the cooperation of PHD and bromodomains in gene regulation and describe a new function of the PHD domain as an intramolecular E3 SUMO ligase. PMID:18082607

Sumoylation of Rap1 mediates the recruitment of TFIID to promote transcription of ribosomal protein genes

PubMed Central

Chymkowitch, Pierre; Nguéa P, Aurélie; Aanes, Håvard; Koehler, Christian J.; Thiede, Bernd; Lorenz, Susanne; Meza-Zepeda, Leonardo A.; Klungland, Arne; Enserink, Jorrit M.

2015-01-01

Transcription factors are abundant Sumo targets, yet the global distribution of Sumo along the chromatin and its physiological relevance in transcription are poorly understood. Using Saccharomyces cerevisiae, we determined the genome-wide localization of Sumo along the chromatin. We discovered that Sumo-enriched genes are almost exclusively involved in translation, such as tRNA genes and ribosomal protein genes (RPGs). Genome-wide expression analysis showed that Sumo positively regulates their transcription. We also discovered that the Sumo consensus motif at RPG promoters is identical to the DNA binding motif of the transcription factor Rap1. We demonstrate that Rap1 is a molecular target of Sumo and that sumoylation of Rap1 is important for cell viability. Furthermore, Rap1 sumoylation promotes recruitment of the basal transcription machinery, and sumoylation of Rap1 cooperates with the target of rapamycin kinase complex 1 (TORC1) pathway to promote RPG transcription. Strikingly, our data reveal that sumoylation of Rap1 functions in a homeostatic feedback loop that sustains RPG transcription during translational stress. Taken together, Sumo regulates the cellular translational capacity by promoting transcription of tRNA genes and RPGs. PMID:25800674

PolySUMOylation by Siz2 and Mms21 triggers relocation of DNA breaks to nuclear pores through the Slx5/Slx8 STUbL

PubMed Central

Horigome, Chihiro; Bustard, Denise E.; Marcomini, Isabella; Delgoshaie, Neda; Tsai-Pflugfelder, Monika; Cobb, Jennifer A.; Gasser, Susan M.

2016-01-01

High-resolution imaging shows that persistent DNA damage in budding yeast localizes in distinct perinuclear foci for repair. The signals that trigger DNA double-strand break (DSB) relocation or determine their destination are unknown. We show here that DSB relocation to the nuclear envelope depends on SUMOylation mediated by the E3 ligases Siz2 and Mms21. In G1, a polySUMOylation signal deposited coordinately by Mms21 and Siz2 recruits the SUMO targeted ubiquitin ligase Slx5/Slx8 to persistent breaks. Both Slx5 and Slx8 are necessary for damage relocation to nuclear pores. When targeted to an undamaged locus, however, Slx5 alone can mediate relocation in G1-phase cells, bypassing the requirement for polySUMOylation. In contrast, in S-phase cells, monoSUMOylation mediated by the Rtt107-stabilized SMC5/6–Mms21 E3 complex drives DSBs to the SUN domain protein Mps3 in a manner independent of Slx5. Slx5/Slx8 and binding to pores favor repair by ectopic break-induced replication and imprecise end-joining. PMID:27056668

Low nuclear body formation and tax SUMOylation do not prevent NF-kappaB promoter activation.

PubMed

Bonnet, Amandine; Randrianarison-Huetz, Voahangy; Nzounza, Patrycja; Nedelec, Martine; Chazal, Maxime; Waast, Laetitia; Pene, Sabrina; Bazarbachi, Ali; Mahieux, Renaud; Bénit, Laurence; Pique, Claudine

2012-09-25

The Tax protein encoded by Human T-lymphotropic virus type 1 (HTLV-1) is a powerful activator of the NF-κB pathway, a property critical for HTLV-1-induced immortalization of CD4⁺ T lymphocytes. Tax permanently stimulates this pathway at a cytoplasmic level by activating the IκB kinase (IKK) complex and at a nuclear level by enhancing the binding of the NF-κB factor RelA to its cognate promoters and by forming nuclear bodies, believed to represent transcriptionally active structures. In previous studies, we reported that Tax ubiquitination and SUMOylation play a critical role in Tax localization and NF-κB activation. Indeed, analysis of lysine Tax mutants fused or not to ubiquitin or SUMO led us to propose a two-step model in which Tax ubiquitination first intervenes to activate IKK while Tax SUMOylation is subsequently required for promoter activation within Tax nuclear bodies. However, recent studies showing that ubiquitin or SUMO can modulate Tax activities in either the nucleus or the cytoplasm and that SUMOylated Tax can serve as substrate for ubiquitination suggested that Tax ubiquitination and SUMOylation may mediate redundant rather than successive functions. In this study, we analyzed the properties of a new Tax mutant that is properly ubiquitinated, but defective for both nuclear body formation and SUMOylation. We report that reducing Tax SUMOylation and nuclear body formation do not alter the ability of Tax to activate IKK, induce RelA nuclear translocation, and trigger gene expression from a NF-κB promoter. Importantly, potent NF-κB promoter activation by Tax despite low SUMOylation and nuclear body formation is also observed in T cells, including CD4⁺ primary T lymphocytes. Moreover, we show that Tax nuclear bodies are hardly observed in HTLV-1-infected T cells. Finally, we provide direct evidence that the degree of NF-κB activation by Tax correlates with the level of Tax ubiquitination, but not SUMOylation. These data reveal that the formation of Tax nuclear bodies, previously associated to transcriptional activities in Tax-transfected cells, is dispensable for NF-κB promoter activation, notably in CD4⁺ T cells. They also provide the first evidence that Tax SUMOylation is not a key determinant for Tax-induced NF-κB activation.

Low nuclear body formation and tax SUMOylation do not prevent NF-kappaB promoter activation

PubMed Central

2012-01-01

Background The Tax protein encoded by Human T-lymphotropic virus type 1 (HTLV-1) is a powerful activator of the NF-κB pathway, a property critical for HTLV-1-induced immortalization of CD4+ T lymphocytes. Tax permanently stimulates this pathway at a cytoplasmic level by activating the IκB kinase (IKK) complex and at a nuclear level by enhancing the binding of the NF-κB factor RelA to its cognate promoters and by forming nuclear bodies, believed to represent transcriptionally active structures. In previous studies, we reported that Tax ubiquitination and SUMOylation play a critical role in Tax localization and NF-κB activation. Indeed, analysis of lysine Tax mutants fused or not to ubiquitin or SUMO led us to propose a two-step model in which Tax ubiquitination first intervenes to activate IKK while Tax SUMOylation is subsequently required for promoter activation within Tax nuclear bodies. However, recent studies showing that ubiquitin or SUMO can modulate Tax activities in either the nucleus or the cytoplasm and that SUMOylated Tax can serve as substrate for ubiquitination suggested that Tax ubiquitination and SUMOylation may mediate redundant rather than successive functions. Results In this study, we analyzed the properties of a new Tax mutant that is properly ubiquitinated, but defective for both nuclear body formation and SUMOylation. We report that reducing Tax SUMOylation and nuclear body formation do not alter the ability of Tax to activate IKK, induce RelA nuclear translocation, and trigger gene expression from a NF-κB promoter. Importantly, potent NF-κB promoter activation by Tax despite low SUMOylation and nuclear body formation is also observed in T cells, including CD4+ primary T lymphocytes. Moreover, we show that Tax nuclear bodies are hardly observed in HTLV-1-infected T cells. Finally, we provide direct evidence that the degree of NF-κB activation by Tax correlates with the level of Tax ubiquitination, but not SUMOylation. Conclusions These data reveal that the formation of Tax nuclear bodies, previously associated to transcriptional activities in Tax-transfected cells, is dispensable for NF-κB promoter activation, notably in CD4+ T cells. They also provide the first evidence that Tax SUMOylation is not a key determinant for Tax-induced NF-κB activation. PMID:23009398

Sumoylation of Rap1 mediates the recruitment of TFIID to promote transcription of ribosomal protein genes.

PubMed

Chymkowitch, Pierre; Nguéa, Aurélie P; Aanes, Håvard; Koehler, Christian J; Thiede, Bernd; Lorenz, Susanne; Meza-Zepeda, Leonardo A; Klungland, Arne; Enserink, Jorrit M

2015-06-01

Transcription factors are abundant Sumo targets, yet the global distribution of Sumo along the chromatin and its physiological relevance in transcription are poorly understood. Using Saccharomyces cerevisiae, we determined the genome-wide localization of Sumo along the chromatin. We discovered that Sumo-enriched genes are almost exclusively involved in translation, such as tRNA genes and ribosomal protein genes (RPGs). Genome-wide expression analysis showed that Sumo positively regulates their transcription. We also discovered that the Sumo consensus motif at RPG promoters is identical to the DNA binding motif of the transcription factor Rap1. We demonstrate that Rap1 is a molecular target of Sumo and that sumoylation of Rap1 is important for cell viability. Furthermore, Rap1 sumoylation promotes recruitment of the basal transcription machinery, and sumoylation of Rap1 cooperates with the target of rapamycin kinase complex 1 (TORC1) pathway to promote RPG transcription. Strikingly, our data reveal that sumoylation of Rap1 functions in a homeostatic feedback loop that sustains RPG transcription during translational stress. Taken together, Sumo regulates the cellular translational capacity by promoting transcription of tRNA genes and RPGs. © 2015 Chymkowitch et al.; Published by Cold Spring Harbor Laboratory Press.

Human T Cell Leukemia Virus Type 2 Tax-Mediated NF-κB Activation Involves a Mechanism Independent of Tax Conjugation to Ubiquitin and SUMO

PubMed Central

Journo, Chloé; Bonnet, Amandine; Favre-Bonvin, Arnaud; Turpin, Jocelyn; Vinera, Jennifer; Côté, Emilie; Chevalier, Sébastien Alain; Kfoury, Youmna; Bazarbachi, Ali

2013-01-01

Permanent activation of the NF-κB pathway by the human T cell leukemia virus type 1 (HTLV-1) Tax (Tax1) viral transactivator is a key event in the process of HTLV-1-induced T lymphocyte immortalization and leukemogenesis. Although encoding a Tax transactivator (Tax2) that activates the canonical NF-κB pathway, HTLV-2 does not cause leukemia. These distinct pathological outcomes might be related, at least in part, to distinct NF-κB activation mechanisms. Tax1 has been shown to be both ubiquitinated and SUMOylated, and these two modifications were originally proposed to be required for Tax1-mediated NF-κB activation. Tax1 ubiquitination allows recruitment of the IKK-γ/NEMO regulatory subunit of the IKK complex together with Tax1 into centrosome/Golgi-associated cytoplasmic structures, followed by activation of the IKK complex and RelA/p65 nuclear translocation. Herein, we compared the ubiquitination, SUMOylation, and acetylation patterns of Tax2 and Tax1. We show that, in contrast to Tax1, Tax2 conjugation to endogenous ubiquitin and SUMO is barely detectable while both proteins are acetylated. Importantly, Tax2 is neither polyubiquitinated on lysine residues nor ubiquitinated on its N-terminal residue. Consistent with these observations, Tax2 conjugation to ubiquitin and Tax2-mediated NF-κB activation is not affected by overexpression of the E2 conjugating enzyme Ubc13. We further demonstrate that a nonubiquitinable, non-SUMOylable, and nonacetylable Tax2 mutant retains a significant ability to activate transcription from a NF-κB-dependent promoter after partial activation of the IKK complex and induction of RelA/p65 nuclear translocation. Finally, we also show that Tax2 does not interact with TRAF6, a protein that was shown to positively regulate Tax1-mediated activation of the NF-κB pathway. PMID:23135727

Systematic Analysis of the Genetic Variability That Impacts SUMO Conjugation and Their Involvement in Human Diseases

NASA Astrophysics Data System (ADS)

Xu, Hao-Dong; Shi, Shao-Ping; Chen, Xiang; Qiu, Jian-Ding

2015-07-01

Protein function has been observed to rely on select essential sites instead of requiring all sites to be indispensable. Small ubiquitin-related modifier (SUMO) conjugation or sumoylation, which is a highly dynamic reversible process and its outcomes are extremely diverse, ranging from changes in localization to altered activity and, in some cases, stability of the modified, has shown to be especially valuable in cellular biology. Motivated by the significance of SUMO conjugation in biological processes, we report here on the first exploratory assessment whether sumoylation related genetic variability impacts protein functions as well as the occurrence of diseases related to SUMO. Here, we defined the SUMOAMVR as sumoylation related amino acid variations that affect sumoylation sites or enzymes involved in the process of connectivity, and categorized four types of potential SUMOAMVRs. We detected that 17.13% of amino acid variations are potential SUMOAMVRs and 4.83% of disease mutations could lead to SUMOAMVR with our system. More interestingly, the statistical analysis demonstrates that the amino acid variations that directly create new potential lysine sumoylation sites are more likely to cause diseases. It can be anticipated that our method can provide more instructive guidance to identify the mechanisms of genetic diseases.

Uncovering Global SUMOylation Signaling Networks in a Site-Specific Manner

PubMed Central

Hendriks, Ivo A.; D’Souza, Rochelle C.J.; Yang, Bing; Verlaan-de Vries, Matty; Mann, Matthias; Vertegaal, Alfred C.O.

2014-01-01

SUMOylation is a reversible post-translational modification essential for genome stability. Using high-resolution mass spectrometry, we have studied global SUMOylation in human cells and in a site-specific manner, identifying a total of over 4,300 SUMOylation sites in over 1,600 proteins. Moreover, for the first time in excess of 1,000 SUMOylation sites were identified under standard growth conditions. SUMOylation dynamics were quantitatively studied in response to SUMO protease inhibition, proteasome inhibition and heat shock. A considerable amount of SUMOylated lysines have previously been reported to be ubiquitylated, acetylated or methylated, indicating crosstalk between SUMO and other post-translational modifications. We identified 70 phosphorylation and 4 acetylation events in close proximity to SUMOylation sites, and provide evidence for acetylation-dependent SUMOylation of endogenous histone H3. SUMOylation regulates target proteins involved in all nuclear processes including transcription, DNA repair, chromatin remodeling, pre-mRNA splicing and ribosome assembly. PMID:25218447

Sumoylation of Smad3 stimulates its nuclear export during PIASy-mediated suppression of TGF-{beta} signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Imoto, Seiyu; Ohbayashi, Norihiko; Ikeda, Osamu

2008-05-30

Sma- and MAD-related protein 3 (Smad3) plays crucial roles in the transforming growth factor-{beta} (TGF-{beta})-mediated signaling pathway, which produce a variety of cellular responses, including cell proliferation and differentiation. In our previous study, we demonstrated that protein inhibitor of activated STATy (PIASy) suppresses TGF-{beta} signaling by interacting with and sumoylating Smad3. In the present study, we examined the molecular mechanisms of Smad3 sumoylation during PIASy-mediated suppression of TGF-{beta} signaling. We found that small-interfering RNA-mediated reduction of endogenous PIASy expression enhanced TGF-{beta}-induced gene expression. Importantly, coexpression of Smad3 with PIASy and SUMO1 affected the DNA-binding activity of Smad3. Furthermore, coexpression ofmore » Smad3 with PIASy and SUMO1 stimulated the nuclear export of Smad3. Finally, fluorescence resonance energy transfer analyses revealed that Smad3 interacted with SUMO1 in the cytoplasm. These results suggest that PIASy regulates TGF-{beta}/Smad3-mediated signaling by stimulating sumoylation and nuclear export of Smad3.« less

RNF4-mediated polyubiquitination regulates the Fanconi anemia/BRCA pathway.

PubMed

Xie, Jenny; Kim, Hyungjin; Moreau, Lisa A; Puhalla, Shannon; Garber, Judy; Al Abo, Muthana; Takeda, Shunichi; D'Andrea, Alan D

2015-04-01

The Fanconi anemia/BRCA (FA/BRCA) pathway is a DNA repair pathway that is required for excision of DNA interstrand cross-links. The 17 known FA proteins, along with several FA-associated proteins (FAAPs), cooperate in this pathway to detect, unhook, and excise DNA cross-links and to subsequently repair the double-strand breaks generated in the process. In the current study, we identified a patient with FA with a point mutation in FANCA, which encodes a mutant FANCA protein (FANCAI939S). FANCAI939S failed to bind to the FAAP20 subunit of the FA core complex, leading to decreased stability. Loss of FAAP20 binding exposed a SUMOylation site on FANCA at amino acid residue K921, resulting in E2 SUMO-conjugating enzyme UBC9-mediated SUMOylation, RING finger protein 4-mediated (RNF4-mediated) polyubiquitination, and proteasome-mediated degradation of FANCA. Mutation of the SUMOylation site of FANCA rescued the expression of the mutant protein. Wild-type FANCA was also subject to SUMOylation, RNF4-mediated polyubiquitination, and degradation, suggesting that regulated release of FAAP20 from FANCA is a critical step in the normal FA pathway. Consistent with this model, cells lacking RNF4 exhibited interstrand cross-linker hypersensitivity, and the gene encoding RNF4 was epistatic with the other genes encoding members of the FA/BRCA pathway. Together, the results from our study underscore the importance of analyzing unique patient-derived mutations for dissecting complex DNA repair processes.

RNF4-mediated polyubiquitination regulates the Fanconi anemia/BRCA pathway

PubMed Central

Xie, Jenny; Kim, Hyungjin; Moreau, Lisa A.; Puhalla, Shannon; Garber, Judy; Al Abo, Muthana; Takeda, Shunichi; D’Andrea, Alan D.

2015-01-01

The Fanconi anemia/BRCA (FA/BRCA) pathway is a DNA repair pathway that is required for excision of DNA interstrand cross-links. The 17 known FA proteins, along with several FA-associated proteins (FAAPs), cooperate in this pathway to detect, unhook, and excise DNA cross-links and to subsequently repair the double-strand breaks generated in the process. In the current study, we identified a patient with FA with a point mutation in FANCA, which encodes a mutant FANCA protein (FANCAI939S). FANCAI939S failed to bind to the FAAP20 subunit of the FA core complex, leading to decreased stability. Loss of FAAP20 binding exposed a SUMOylation site on FANCA at amino acid residue K921, resulting in E2 SUMO-conjugating enzyme UBC9-mediated SUMOylation, RING finger protein 4–mediated (RNF4-mediated) polyubiquitination, and proteasome-mediated degradation of FANCA. Mutation of the SUMOylation site of FANCA rescued the expression of the mutant protein. Wild-type FANCA was also subject to SUMOylation, RNF4-mediated polyubiquitination, and degradation, suggesting that regulated release of FAAP20 from FANCA is a critical step in the normal FA pathway. Consistent with this model, cells lacking RNF4 exhibited interstrand cross-linker hypersensitivity, and the gene encoding RNF4 was epistatic with the other genes encoding members of the FA/BRCA pathway. Together, the results from our study underscore the importance of analyzing unique patient-derived mutations for dissecting complex DNA repair processes. PMID:25751062

Human Adenovirus Core Protein V Is Targeted by the Host SUMOylation Machinery To Limit Essential Viral Functions.

PubMed

Freudenberger, Nora; Meyer, Tina; Groitl, Peter; Dobner, Thomas; Schreiner, Sabrina

2018-02-15

Human adenoviruses (HAdV) are nonenveloped viruses containing a linear, double-stranded DNA genome surrounded by an icosahedral capsid. To allow proper viral replication, the genome is imported through the nuclear pore complex associated with viral core proteins. Until now, the role of these incoming virion proteins during the early phase of infection was poorly understood. The core protein V is speculated to bridge the core and the surrounding capsid. It binds the genome in a sequence-independent manner and localizes in the nucleus of infected cells, accumulating at nucleoli. Here, we show that protein V contains conserved SUMO conjugation motifs (SCMs). Mutation of these consensus motifs resulted in reduced SUMOylation of the protein; thus, protein V represents a novel target of the host SUMOylation machinery. To understand the role of protein V SUMO posttranslational modification during productive HAdV infection, we generated a replication-competent HAdV with SCM mutations within the protein V coding sequence. Phenotypic analyses revealed that these SCM mutations are beneficial for adenoviral replication. Blocking protein V SUMOylation at specific sites shifts the onset of viral DNA replication to earlier time points during infection and promotes viral gene expression. Simultaneously, the altered kinetics within the viral life cycle are accompanied by more efficient proteasomal degradation of host determinants and increased virus progeny production than that observed during wild-type infection. Taken together, our studies show that protein V SUMOylation reduces virus growth; hence, protein V SUMOylation represents an important novel aspect of the host antiviral strategy to limit virus replication and thereby points to potential intervention strategies. IMPORTANCE Many decades of research have revealed that HAdV structural proteins promote viral entry and mainly physical stability of the viral genome in the capsid. Our work over the last years showed that this concept needs expansion as the functions are more diverse. We showed that capsid protein VI regulates the antiviral response by modulation of the transcription factor Daxx during infection. Moreover, core protein VII interacts with SPOC1 restriction factor, which is beneficial for efficient viral gene expression. Here, we were able to show that core protein V also represents a novel substrate of the host SUMOylation machinery and contains several conserved SCMs; mutation of these consensus motifs reduced SUMOylation of the protein. Unexpectedly, we observed that introducing these mutations into HAdV promotes adenoviral replication. In conclusion, we offer novel insights into adenovirus core proteins and provide evidence that SUMOylation of HAdV factors regulates replication efficiency. Copyright © 2018 American Society for Microbiology.

Production and Purification of Recombinant SUMOylated Proteins Using Engineered Bacteria.

PubMed

Brockly, Frédérique; Piechaczyk, Marc; Bossis, Guillaume

2016-01-01

SUMO is a ubiquitin-like protein that is covalently conjugated to numerous cellular proteins to modify their function and fate. Although large progresses have been made in the identification of SUMOylated proteins, the molecular consequences of their SUMOylation are generally unknown. This is, most often, due to the low abundance of SUMOylated proteins in the cell, usually less than 1 % of a given protein being modified at steady state. To gain insights into the role of specific SUMOylation targets, SUMO conjugation can be reconstituted in vitro using purified proteins. However, for most substrates, the efficiency of in vitro SUMOylation is too low to obtain sufficient amounts of their SUMOylated forms for biochemical studies. Here, we describe a detailed protocol to purify large amounts of recombinant SUMOylated proteins using bacteria modified to express His-tagged SUMO as well as the SUMO-activating and -conjugating enzymes.

Preparation of sumoylated substrates for biochemical analysis.

PubMed

Knipscheer, Puck; Klug, Helene; Sixma, Titia K; Pichler, Andrea

2009-01-01

Covalent modification of proteins with SUMO (small ubiquitin related modifier) affects many cellular processes like transcription, nuclear transport, DNA repair and cell cycle progression. Although hundreds of SUMO targets have been identified, for several of them the function remains obscure. In the majority of cases sumoylation is investigated via "loss of modification" analysis by mutating the relevant target lysine. However, in other cases this approach is not successful since mapping of the modification site is problematic or mutation does not cause an obvious phenotype. These latter cases ask for different approaches to investigate the target modification. One possibility is to choose the opposite approach, a "gain in modification" analysis by producing both SUMO modified and unmodified protein in vitro and comparing them in functional assays. Here, we describe the purification of the ubiquitin conjugating enzyme E2-25K, its in vitro sumoylation with recombinant enzymes and the subsequent separation and purification of the modified and the unmodified forms.

RXR is an essential component of the oncogenic PML/RARA complex in vivo.

PubMed

Zhu, Jun; Nasr, Rihab; Pérès, Laurent; Riaucoux-Lormière, Florence; Honoré, Nicole; Berthier, Caroline; Kamashev, Dmitrii; Zhou, Jun; Vitoux, Dominique; Lavau, Catherine; de Thé, Hugues

2007-07-01

Although PML-enforced RARA homodimerization allows PML/RARA to bind DNA independently of its coreceptor RXR, the latter was identified within the PML/RARA complex. We demonstrate that a PML/RARA mutant defective for RXR binding fails to trigger APL development in transgenic mice, although it still transforms primary hematopoietic progenitors ex vivo. RXR enhances PML/RARA binding to DNA and is required for rexinoid-induced APL differentiation. In RA-treated PML/RARA-transformed cells, the absence of RXR binding results in monocytic, rather than granulocytic, differentiation. PML/RARA enhances posttranslational modifications of RXRA, including its sumoylation, suggesting that PML-bound sumoylation enzymes target RXRA and possibly other PML/RARA-bound chromatin proteins, further contributing to deregulated transcription. Thus, unexpectedly, RXR contributes to several critical aspects of in vivo transformation.

Glucocorticoid-induced tethered transrepression requires SUMOylation of GR and formation of a SUMO-SMRT/NCoR1-HDAC3 repressing complex

PubMed Central

Hua, Guoqiang; Ganti, Krishna Priya; Chambon, Pierre

2016-01-01

Upon binding of a glucocorticoid (GC), the GC receptor (GR) can exert one of three transcriptional regulatory functions. We recently reported that SUMOylation of the GR at position K293 in humans (K310 in mice) within the N-terminal domain is indispensable for GC-induced evolutionary conserved inverted repeated negative GC response element (IR nGRE)-mediated direct transrepression. We now demonstrate that the integrity of this GR SUMOylation site is mandatory for the formation of a GR-small ubiquitin-related modifiers (SUMOs)-SMRT/NCoR1-HDAC3 repressing complex, which is indispensable for NF-κB/AP1-mediated GC-induced tethered indirect transrepression in vitro. Using GR K310R mutant mice or mice containing the N-terminal truncated GR isoform GRα-D3 lacking the K310 SUMOylation site, revealed a more severe skin inflammation than in WT mice. Importantly, cotreatment with dexamethasone (Dex) could not efficiently suppress a 12-O-tetradecanoylphorbol-13-acetate (TPA)–induced skin inflammation in these mutant mice, whereas it was clearly decreased in WT mice. In addition, in mice selectively ablated in skin keratinocytes for either nuclear receptor corepressor 1 (NCoR1)/silencing mediator for retinoid or thyroid-hormone receptors (SMRT) corepressors or histone deacetylase 3 (HDAC3), Dex-induced tethered transrepression and the formation of a repressing complex on DNA-bound NF-κB/AP1 were impaired. We previously suggested that GR ligands that would lack both (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression activities of GCs may preferentially exert the therapeutically beneficial GC antiinflammatory properties. Interestingly, we now identified a nonsteroidal antiinflammatory selective GR agonist (SEGRA) that selectively lacks both Dex-induced (+)GRE-mediated transactivation and IR nGRE-mediated direct transrepression functions, while still exerting a tethered indirect transrepression activity and could therefore be clinically lesser debilitating on long-term GC therapy. PMID:26712006

The Key Regulator for Language and Speech Development, FOXP2, is a Novel Substrate for SUMOylation.

PubMed

Meredith, Leslie J; Wang, Chiung-Min; Nascimento, Leticia; Liu, Runhua; Wang, Lizhong; Yang, Wei-Hsiung

2016-02-01

Transcription factor forkhead box protein P2 (FOXP2) plays an essential role in the development of language and speech. However, the transcriptional activity of FOXP2 regulated by the post-translational modifications remains unknown. Here, we demonstrated that FOXP2 is clearly defined as a SUMO target protein at the cellular levels as FOXP2 is covalently modified by both SUMO1 and SUMO3. Furthermore, SUMOylation of FOXP2 was significantly decreased by SENP2 (a specific SUMOylation protease). We further showed that FOXP2 is selectively SUMOylated in vivo on a phylogenetically conserved lysine 674 but the SUMOylation does not alter subcellular localization and stability of FOXP2. Interestingly, we observed that human etiological FOXP2 R553H mutation robustly reduces its SUMOylation potential as compared to wild-type FOXP2. In addition, the acidic residues downstream the core SUMO motif on FOXP2 are required for its full SUMOylation capacity. Finally, our functional analysis using reporter gene assays showed that SUMOylation may modulate transcriptional activity of FOXP2 in regulating downstream target genes (DISC1, SRPX2, and MiR200c). Altogether, we provide the first evidence that FOXP2 is a substrate for SUMOylation and SUMOylation of FOXP2 plays a functional role in regulating its transcriptional activity. © 2015 Wiley Periodicals, Inc.

The Key Regulator for Language and Speech Development, FOXP2, is a Novel Substrate for SUMOylation

PubMed Central

Meredith, Leslie J.; Wang, Chiung-Min; Nascimento, Leticia; Liu, Runhua; Wang, Lizhong; Yang, Wei-Hsiung

2017-01-01

Transcription factor forkhead box protein P2 (FOXP2) plays an essential role in the development of language and speech. However, the transcriptional activity of FOXP2 regulated by the post-translational modifications remains unknown. Here we demonstrated that FOXP2 is clearly defined as a SUMO target protein at the cellular levels as FOXP2 is covalently modified by both SUMO1 and SUMO3. Furthermore, SUMOylation of FOXP2 was significantly decreased by SENP2 (a specific SUMOylation protease). We further showed that FOXP2 is selectively SUMOylated in vivo on a phylogenetically conserved lysine 674 but the SUMOylation does not alter subcellular localization and stability of FOXP2. Interestingly, we observed that human etiological FOXP2 R553H mutation robustly reduces its SUMOylation potential as compared to wild-type FOXP2. In addition, the acidic residues downstream the core SUMO motif on FOXP2 are required for its full SUMOylation capacity. Finally, our functional analysis using reporter gene assays showed that SUMOylation may modulate transcriptional activity of FOXP2 in regulating downstream target genes (DISC1, SRPX2 and MiR200c). Altogether, we provide the first evidence that FOXP2 is a substrate for SUMOylation and SUMOylation of FOXP2 plays a functional role in regulating its transcriptional activity. PMID:26212494

Akt SUMOylation regulates cell proliferation and tumorigenesis.

PubMed

Li, Rong; Wei, Jie; Jiang, Cong; Liu, Dongmei; Deng, Lu; Zhang, Kai; Wang, Ping

2013-09-15

Proto-oncogene Akt plays essential roles in cell proliferation and tumorigenesis. Full activation of Akt is regulated by phosphorylation, ubiquitination, and acetylation. Here we report that SUMOylation of Akt is a novel mechanism for its activation. Systematically analyzing the role of lysine residues in Akt activation revealed that K276, which is located in a SUMOylation consensus motif, is essential for Akt activation. Ectopic or endogenous Akt1 could be modified by SUMOylation. RNA interference-mediated silencing of UBC9 reduced Akt SUMOylation, which was promoted by SUMO E3 ligase PIAS1 and reversed by the SUMO-specific protease SENP1. Although multiple sites on Akt could be SUMOylated, K276 was identified as a major SUMO acceptor site. K276R or E278A mutation reduced SUMOylation of Akt but had little effect on its ubiquitination. Strikingly, these mutations also completely abolished Akt kinase activity. In support of these results, we found that expression of PIAS1 and SUMO1 increased Akt activity, whereas expression of SENP1 reduced Akt1 activity. Interestingly, the cancer-derived mutant E17K in Akt1 that occurs in various cancers was more efficiently SUMOylated than wild-type Akt. Moreover, SUMOylation loss dramatically reduced Akt1 E17K-mediated cell proliferation, cell migration, and tumorigenesis. Collectively, our findings establish that Akt SUMOylation provides a novel regulatory mechanism for activating Akt function. ©2013 AACR.

PIASy Mediates SUMO-2/3 Conjugation of Poly(ADP-ribose) Polymerase 1 (PARP1) on Mitotic Chromosomes*

PubMed Central

Ryu, Hyunju; Al-Ani, Gada; Deckert, Katelyn; Kirkpatrick, Donald; Gygi, Steven P.; Dasso, Mary; Azuma, Yoshiaki

2010-01-01

PIASy is a small ubiquitin-related modifier (SUMO) ligase that modifies chromosomal proteins in mitotic Xenopus egg extracts and plays an essential role in mitotic chromosome segregation. We have isolated a novel SUMO-2/3-modified mitotic chromosomal protein and identified it as poly(ADP-ribose) polymerase 1 (PARP1). PARP1 was robustly conjugated to SUMO-2/3 on mitotic chromosomes but not on interphase chromatin. PIASy promotes SUMOylation of PARP1 both in egg extracts and in vitro reconstituted SUMOylation assays. Through tandem mass spectrometry analysis of mitotically SUMOylated PARP1, we identified a residue within the BRCA1 C-terminal domain of PARP1 (lysine 482) as its primary SUMOylation site. Mutation of this residue significantly reduced PARP1 SUMOylation in egg extracts and enhanced the accumulation of species derived from modification of secondary lysine residues in assays using purified components. SUMOylation of PARP1 did not alter in vitro PARP1 enzyme activity, poly-ADP-ribosylation (PARylation), nor did inhibition of SUMOylation of PARP1 alter the accumulation of PARP1 on mitotic chromosomes, suggesting that SUMOylation regulates neither the intrinsic activity of PARP1 nor its localization. However, loss of SUMOylation increased PARP1-dependent PARylation on isolated chromosomes, indicating SUMOylation controls the capacity of PARP1 to modify other chromatin-associated proteins. PMID:20228053

SUMOylation in Neurological Diseases.

PubMed

Liu, F-Y; Liu, Y-F; Yang, Y; Luo, Z-W; Xiang, J-W; Chen, Z-G; Qi, R-L; Yang, T-H; Xiao, Y; Qing, W-J; Li, D W-C

2017-01-01

Since the discovery of SUMOs (small ubiquitin-like modifiers) over 20 years ago, sumoylation has recently emerged as an important posttranslational modification involved in almost all aspects of cellular physiology. In neurons, sumoylation dynamically modulates protein function and consequently plays an important role in neuronal maturation, synapse formation and plasticity. Thus, the dysfunction of sumoylation pathway is associated with many different neurological disorders. Hundreds of different proteins implicated in the pathogenesis of neurological disorders are SUMO-modified, indicating the importance of sumoylation involved in the neurological diseases. In this review, we summarize the growing findings on protein sumoylation in neuronal function and dysfunction. It is essential to have a thorough understanding on the mechanism how sumoylation contributes to neurological diseases in developing efficient therapy for these diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

When SUMO met splicing.

PubMed

Pozzi, Berta; Mammi, Pablo; Bragado, Laureano; Giono, Luciana E; Srebrow, Anabella

2018-05-09

Spliceosomal proteins have been revealed as SUMO conjugation targets. Moreover, we have reported that many of these are in a SUMO-conjugated form when bound to a pre-mRNA substrate during a splicing reaction. We demonstrated that SUMOylation of Prp3 (PRPF3), a component of the U4/U6 di-snRNP, is required for U4/U6•U5 tri-snRNP formation and/or recruitment to active spliceosomes. Expanding upon our previous results, we have shown that the splicing factor SRSF1 stimulates SUMO conjugation to several spliceosomal proteins. Given the relevance of the splicing process, as well as the complex and dynamic nature of its governing machinery, the spliceosome, the molecular mechanisms that modulate its function represent an attractive topic of research. We posit that SUMO conjugation could represent a way of modulating spliceosome assembly and thus, splicing efficiency. How cycles of SUMOylation/de-SUMOylation of spliceosomal proteins become integrated throughout the highly choreographed spliceosomal cycle awaits further investigation.

Development of a high-throughput screen to detect inhibitors of TRPS1 sumoylation.

PubMed

Brandt, Martin; Szewczuk, Lawrence M; Zhang, Hong; Hong, Xuan; McCormick, Patricia M; Lewis, Tia S; Graham, Taylor I; Hung, Sunny T; Harper-Jones, Amber D; Kerrigan, John J; Wang, Da-Yuan; Dul, Edward; Hou, Wangfang; Ho, Thau F; Meek, Thomas D; Cheung, Mui H; Johanson, Kyung O; Jones, Christopher S; Schwartz, Benjamin; Kumar, Sanjay; Oliff, Allen I; Kirkpatrick, Robert B

2013-06-01

Small ubiquitin-like modifier (SUMO) belongs to the family of ubiquitin-like proteins (Ubls) that can be reversibly conjugated to target-specific lysines on substrate proteins. Although covalently sumoylated products are readily detectible in gel-based assays, there has been little progress toward the development of robust quantitative sumoylation assay formats for the evaluation of large compound libraries. In an effort to identify inhibitors of ubiquitin carrier protein 9 (Ubc9)-dependent sumoylation, a high-throughput fluorescence polarization assay was developed, which allows detection of Lys-1201 sumoylation, corresponding to the major site of functional sumoylation within the transcriptional repressor trichorhino-phalangeal syndrome type I protein (TRPS1). A minimal hexapeptide substrate peptide, TMR-VVK₁₂₀₁TEK, was used in this assay format to afford high-throughput screening of the GlaxoSmithKline diversity compound collection. A total of 728 hits were confirmed but no specific noncovalent inhibitors of Ubc9 dependent trans-sumoylation were found. However, several diaminopyrimidine compounds were identified as inhibitors in the assay with IC₅₀ values of 12.5 μM. These were further characterized to be competent substrates which were subject to sumoylation by SUMO-Ubc9 and which were competitive with the sumoylation of the TRPS1 peptide substrates.

PML/RARA oxidation and arsenic binding initiate the antileukemia response of As2O3.

PubMed

Jeanne, Marion; Lallemand-Breitenbach, Valérie; Ferhi, Omar; Koken, Marcel; Le Bras, Morgane; Duffort, Stéphanie; Peres, Laurent; Berthier, Caroline; Soilihi, Hassane; Raught, Brian; de Thé, Hugues

2010-07-13

As(2)O(3) cures acute promyelocytic leukemia (APL) by initiating PML/RARA oncoprotein degradation, through sumoylation of its PML moiety. However, how As(2)O(3) initiates PML sumoylation has remained largely unexplained. As(2)O(3) binds vicinal cysteines and increases reactive oxygen species (ROS) production. We demonstrate that upon As(2)O(3) exposure, PML undergoes ROS-initiated intermolecular disulfide formation and binds arsenic directly. Disulfide-linked PML or PML/RARA multimers form nuclear matrix-associated nuclear bodies (NBs), become sumoylated and are degraded. Hematopoietic progenitors transformed by an As(2)O(3)-binding PML/RARA mutant exhibit defective As(2)O(3) response. Conversely, nonarsenical oxidants elicit PML/RARA multimerization, NB-association, degradation, and leukemia response in vivo, but do not affect PLZF/RARA-driven APLs. Thus, PML oxidation regulates NB-biogenesis, while oxidation-enforced PML/RARA multimerization and direct arsenic-binding cooperate to enforce APL's exquisite As(2)O(3) sensitivity. Copyright (c) 2010 Elsevier Inc. All rights reserved.

Sumoylation of FOXP2 regulates motor function and vocal communication through Purkinje cell development

PubMed Central

Usui, Noriyoshi; Co, Marissa; Harper, Matthew; Rieger, Michael A.; Dougherty, Joseph D.; Konopka, Genevieve

2016-01-01

Background Mutations in the gene encoding the transcription factor forkhead box P2, FOXP2, result in brain developmental abnormalities including reduced gray matter in both human patients and rodent models, and speech and language deficits. However, neither the region-specific function of FOXP2 in the brain, in particular the cerebellum, nor the effects of any post-translational modifications of FOXP2 in the brain and disorders have been explored. Methods We characterized sumoylation of FOXP2 biochemically, and analyzed the region-specific function and sumoylation of FOXP2 in the developing mouse cerebellum. Using in utero electroporation to manipulate the sumoylation-state of Foxp2 as well as Foxp2 expression levels in Purkinje cells (PCs) of the cerebellum in vivo, we reduced Foxp2 expression approximately 40% in the mouse cerebellum. Such a reduction approximates the haploinsufficiency observed in human patients who demonstrate speech and language impairments. Results We identified sumoylation of FOXP2 at K674 (K673 in mouse) in the cerebellum of neonates. In vitro co-immunoprecipitation and in vivo colocalization experiments suggest that PIAS3 acts as the SUMO E3 ligase for FOXP2 sumoylation. This sumoylation modifies transcriptional regulation by FOXP2. We demonstrate that Foxp2 sumoylation is required for regulation of cerebellar motor function and vocal communication, likely through dendritic outgrowth and arborization of PCs in the mouse cerebellum. Conclusions Sumoylation of Foxp2 in neonatal mouse cerebellum regulates PC development as well as motor functions and vocal communication, demonstrating evidence for sumoylation in regulating mammalian behaviors. PMID:27009683

Mutually exclusive STAT1 modifications identified by Ubc9/substrate dimerization-dependent SUMOylation.

PubMed

Zimnik, Susan; Gaestel, Matthias; Niedenthal, Rainer

2009-03-01

Post-translational modifications control the physiological activity of the signal transducer and activator of transcription STAT1. While phosphorylation at tyrosine Y701 is a prerequisite for STAT1 dimerization, its SUMOylation represses the transcriptional activity. Recently, we have demonstrated that SUMOylation at lysine K703 inhibits the phosphorylation of nearby localized Y701 of STAT1. Here, we analysed the influence of phosphorylation of Y701 on SUMOylation of K703 in vivo. For that reason, an Ubc9/substrate dimerization-dependent SUMOylation (USDDS) system was developed, which consists of fusions of the SUMOylation substrate and of the SUMO-conjugating enzyme Ubc9 to the chemically activatable heterodimerization domains FKBP and FRB, respectively. When FKBP fusion proteins of STAT1, p53, CRSP9, FOS, CSNK2B, HES1, TCF21 and MYF6 are coexpressed with Ubc9-FRB, treatment of HEK293 cells with the rapamycin-related dimerizer compound AP21967 induces SUMOylation of these proteins in vivo. For STAT1-FKBP and p53-FKBP we show that this SUMOylation takes place at their specific SUMOylation sites in vivo. Using USDDS, we then demonstrate that STAT1 phosphorylation at Y701 induced by interferon-beta treatment inhibits SUMOylation of K703 in vivo. Thus, pY701 and SUMO-K703 of STAT1 represent mutually exclusive modifications, which prevent signal integration at this molecule and probably ensure the existence of differentially modified subpopulations of STAT1 necessary for its regulated nuclear cytoplasmic activation/inactivation cycle.

Oxidative stress–induced assembly of PML nuclear bodies controls sumoylation of partner proteins

PubMed Central

Sahin, Umut; Ferhi, Omar; Jeanne, Marion; Benhenda, Shirine; Berthier, Caroline; Jollivet, Florence; Niwa-Kawakita, Michiko; Faklaris, Orestis; Setterblad, Niclas; Lallemand-Breitenbach, Valérie

2014-01-01

The promyelocytic leukemia (PML) protein organizes PML nuclear bodies (NBs), which are stress-responsive domains where many partner proteins accumulate. Here, we clarify the basis for NB formation and identify stress-induced partner sumoylation as the primary NB function. NB nucleation does not rely primarily on intermolecular interactions between the PML SUMO-interacting motif (SIM) and SUMO, but instead results from oxidation-mediated PML multimerization. Oxidized PML spherical meshes recruit UBC9, which enhances PML sumoylation, allow partner recruitment through SIM interactions, and ultimately enhance partner sumoylation. Intermolecular SUMO–SIM interactions then enforce partner sequestration within the NB inner core. Accordingly, oxidative stress enhances NB formation and global sumoylation in vivo. Some NB-associated sumoylated partners also become polyubiquitinated by RNF4, precipitating their proteasomal degradation. As several partners are protein-modifying enzymes, NBs could act as sensors that facilitate and confer oxidative stress sensitivity not only to sumoylation but also to other post-translational modifications, thereby explaining alterations of stress response upon PML or NB loss. PMID:24637324

A Non-SUMOylated Tax Protein Is Still Functional for NF-κB Pathway Activation

PubMed Central

Pène, Sabrina; Waast, Laetitia; Bonnet, Amandine; Bénit, Laurence

2014-01-01

ABSTRACT Whether NF-κB promoter transactivation by the human T-cell leukemia virus type 1 (HTLV-1) Tax protein requires Tax SUMOylation is still a matter of debate. In this study, we revisited the role of Tax SUMOylation using a strategy based on the targeting of Ubc9, the unique E2 SUMO-conjugating enzyme. We show that either a catalytically inactive form of Ubc9 (Ubc9-C93S) or Ubc9 small interfering RNA (siRNA) dramatically reduces Tax conjugation to endogenous SUMO-1 or SUMO-2/3, demonstrating that as expected, Tax SUMOylation is under the control of the catalytic activity of Ubc9. We further report that a non-SUMOylated Tax protein produced in 293T cells is still able to activate either a transfected or an integrated NF-κB reporter promoter and to induce expression of an NF-κB-regulated endogenous gene. Importantly, blocking Ubc9 activity in T cells also results in the production of a non-SUMOylated Tax that is still fully functional for the activation of a NF-κB promoter. These results provide the definitive evidence that Tax SUMOylation is not required for NF-κB-driven gene induction. IMPORTANCE Human T-cell leukemia virus type 1 is able to transform CD4+ T lymphocytes. The viral oncoprotein Tax plays a key role in this process by promoting cell proliferation and survival, mainly through permanent activation of the NF-κB pathway. Elucidating the molecular mechanisms involved in NF-κB pathway activation by Tax is therefore a key issue to understand HTLV-1-mediated transformation. Tax SUMOylation was initially proposed to be critical for Tax-induced NF-κB promoter activation, which was challenged by our later observation that a low-level-SUMOylated Tax mutant was still functional for activation of NF-κB promoters. To clarify the role of Tax SUMOylation, we set up a new approach based on the inhibition of the SUMOylation machinery in Tax-expressing cells. We show that blocking the SUMO-conjugating enzyme Ubc9 abolishes Tax SUMOylation and that a non-SUMOylated Tax still activates NF-κB promoters in either adherent cells or T cells. PMID:24991007

A non-SUMOylated tax protein is still functional for NF-κB pathway activation.

PubMed

Pène, Sabrina; Waast, Laetitia; Bonnet, Amandine; Bénit, Laurence; Pique, Claudine

2014-09-01

Whether NF-κB promoter transactivation by the human T-cell leukemia virus type 1 (HTLV-1) Tax protein requires Tax SUMOylation is still a matter of debate. In this study, we revisited the role of Tax SUMOylation using a strategy based on the targeting of Ubc9, the unique E2 SUMO-conjugating enzyme. We show that either a catalytically inactive form of Ubc9 (Ubc9-C93S) or Ubc9 small interfering RNA (siRNA) dramatically reduces Tax conjugation to endogenous SUMO-1 or SUMO-2/3, demonstrating that as expected, Tax SUMOylation is under the control of the catalytic activity of Ubc9. We further report that a non-SUMOylated Tax protein produced in 293T cells is still able to activate either a transfected or an integrated NF-κB reporter promoter and to induce expression of an NF-κB-regulated endogenous gene. Importantly, blocking Ubc9 activity in T cells also results in the production of a non-SUMOylated Tax that is still fully functional for the activation of a NF-κB promoter. These results provide the definitive evidence that Tax SUMOylation is not required for NF-κB-driven gene induction. Human T-cell leukemia virus type 1 is able to transform CD4(+) T lymphocytes. The viral oncoprotein Tax plays a key role in this process by promoting cell proliferation and survival, mainly through permanent activation of the NF-κB pathway. Elucidating the molecular mechanisms involved in NF-κB pathway activation by Tax is therefore a key issue to understand HTLV-1-mediated transformation. Tax SUMOylation was initially proposed to be critical for Tax-induced NF-κB promoter activation, which was challenged by our later observation that a low-level-SUMOylated Tax mutant was still functional for activation of NF-κB promoters. To clarify the role of Tax SUMOylation, we set up a new approach based on the inhibition of the SUMOylation machinery in Tax-expressing cells. We show that blocking the SUMO-conjugating enzyme Ubc9 abolishes Tax SUMOylation and that a non-SUMOylated Tax still activates NF-κB promoters in either adherent cells or T cells. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Sumoylation of FOXP2 Regulates Motor Function and Vocal Communication Through Purkinje Cell Development.

PubMed

Usui, Noriyoshi; Co, Marissa; Harper, Matthew; Rieger, Michael A; Dougherty, Joseph D; Konopka, Genevieve

2017-02-01

Mutations in the gene encoding the transcription factor forkhead box P2 (FOXP2) result in brain developmental abnormalities, including reduced gray matter in both human patients and rodent models and speech and language deficits. However, neither the region-specific function of FOXP2 in the brain, in particular the cerebellum, nor the effects of any posttranslational modifications of FOXP2 in the brain and disorders have been explored. We characterized sumoylation of FOXP2 biochemically and analyzed the region-specific function and sumoylation of FOXP2 in the developing mouse cerebellum. Using in utero electroporation to manipulate the sumoylation state of FOXP2 as well as Foxp2 expression levels in Purkinje cells of the cerebellum in vivo, we reduced Foxp2 expression approximately 40% in the mouse cerebellum. Such a reduction approximates the haploinsufficiency observed in human patients who demonstrate speech and language impairments. We identified sumoylation of FOXP2 at K674 (K673 in mice) in the cerebellum of neonates. In vitro co-immunoprecipitation and in vivo colocalization experiments suggest that PIAS3 acts as the small ubiquitin-like modifier E3 ligase for FOXP2 sumoylation. This sumoylation modifies transcriptional regulation by FOXP2. We demonstrated that FOXP2 sumoylation is required for regulation of cerebellar motor function and vocal communication, likely through dendritic outgrowth and arborization of Purkinje cells in the mouse cerebellum. Sumoylation of FOXP2 in neonatal mouse cerebellum regulates Purkinje cell development and motor functions and vocal communication, demonstrating evidence for sumoylation in regulating mammalian behaviors. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Epstein-Barr Virus Latent Membrane Protein 1 Regulates the Function of Interferon Regulatory Factor 7 by Inducing Its Sumoylation

PubMed Central

Bentz, Gretchen L.; Shackelford, Julia

2012-01-01

Epstein-Barr virus (EBV) latent membrane protein 1 (LMP1) induces multiple signal transduction pathways during latent EBV infection via its C-terminal activating region 1 (CTAR1), CTAR2, and the less-studied CTAR3. One mechanism by which LMP1 regulates cellular activation is through the induction of protein posttranslational modifications, including phosphorylation and ubiquitination. We recently documented that LMP1 induces a third major protein modification by physically interacting with the SUMO-conjugating enzyme Ubc9 through CTAR3 and inducing the sumoylation of cellular proteins in latently infected cells. We have now identified a specific target of LMP1-induced sumoylation, interferon regulatory factor 7 (IRF7). We hypothesize that during EBV latency, LMP1 induces the sumoylation of IRF7, limiting its transcriptional activity and modulating the activation of innate immune responses. Our data show that endogenously sumoylated IRF7 is detected in latently infected EBV lymphoblastoid cell lines. LMP1 expression coincided with increased sumoylation of IRF7 in a CTAR3-dependent manner. Additional experiments show that LMP1 CTAR3-induced sumoylation regulates the expression and function of IRF7 by decreasing its turnover, increasing its nuclear retention, decreasing its DNA binding, and limiting its transcriptional activation. Finally, we identified that IRF7 is sumoylated at lysine 452. These data demonstrate that LMP1 CTAR3 does in fact function in intracellular signaling, leading to biologic effects. We propose that CTAR3 is an important signaling region of LMP1 that regulates protein function by sumoylation. We have shown specifically that LMP1 CTAR3, in cooperation with CTAR2, can limit the ability of IRF7 to induce innate immune responses by inducing the sumoylation of IRF7. PMID:22951831

Detection of Protein SUMOylation In Situ by Proximity Ligation Assays.

PubMed

Sahin, Umut; Jollivet, Florence; Berthier, Caroline; de Thé, Hugues; Lallemand-Breitenbach, Valérie

2016-01-01

Sumoylation is a posttranslational process essential for life and concerns a growing number of crucial proteins. Understanding the influence of this phenomenon on individual proteins or on cellular pathways in which they function has become an intense area of research. A critical step in studying protein sumoylation is to detect sumoylated forms of a particular protein. This has proven to be a challenging task for a number of reasons, especially in the case of endogenous proteins and in vivo studies or when studying rare cells such as stem cells. Proximity ligation assays that allow detection of closely interacting protein partners can be adapted for initial detection of endogenous sumoylation or ubiquitination in a rapid, ultrasensitive, and cheap manner. In addition, modified forms of a given protein can be detected in situ in various cellular compartments. Finally, the flexibility of this technique may allow rapid screening of drugs and stress signals that may modulate protein sumoylation.

PDSM, a motif for phosphorylation-dependent SUMO modification

PubMed Central

Hietakangas, Ville; Anckar, Julius; Blomster, Henri A.; Fujimoto, Mitsuaki; Palvimo, Jorma J.; Nakai, Akira; Sistonen, Lea

2006-01-01

SUMO (small ubiquitin-like modifier) modification regulates many cellular processes, including transcription. Although sumoylation often occurs on specific lysines within the consensus tetrapeptide ΨKxE, other modifications, such as phosphorylation, may regulate the sumoylation of a substrate. We have discovered PDSM (phosphorylation-dependent sumoylation motif), composed of a SUMO consensus site and an adjacent proline-directed phosphorylation site (ΨKxExxSP). The highly conserved motif regulates phosphorylation-dependent sumoylation of multiple substrates, such as heat-shock factors (HSFs), GATA-1, and myocyte enhancer factor 2. In fact, the majority of the PDSM-containing proteins are transcriptional regulators. Within the HSF family, PDSM is conserved between two functionally distinct members, HSF1 and HSF4b, whose transactivation capacities are repressed through the phosphorylation-dependent sumoylation. As the first recurrent sumoylation determinant beyond the consensus tetrapeptide, the PDSM provides a valuable tool in predicting new SUMO substrates. PMID:16371476

A new MCM modification cycle regulates DNA replication initiation.

PubMed

Wei, Lei; Zhao, Xiaolan

2016-03-01

The MCM DNA helicase is a central regulatory target during genome replication. MCM is kept inactive during G1, and it initiates replication after being activated in S phase. During this transition, the only known chemical change to MCM is the gain of multisite phosphorylation that promotes cofactor recruitment. Because replication initiation is intimately linked to multiple biological cues, additional changes to MCM can provide further regulatory points. Here, we describe a yeast MCM SUMOylation cycle that regulates replication. MCM subunits undergo SUMOylation upon loading at origins in G1 before MCM phosphorylation. MCM SUMOylation levels then decline as MCM phosphorylation levels rise, thus suggesting an inhibitory role of MCM SUMOylation during replication. Indeed, increasing MCM SUMOylation impairs replication initiation, partly through promoting the recruitment of a phosphatase that decreases MCM phosphorylation and activation. We propose that MCM SUMOylation counterbalances kinase-based regulation, thus ensuring accurate control of replication initiation.

SUMO Modification Stabilizes Enterovirus 71 Polymerase 3D To Facilitate Viral Replication

PubMed Central

Liu, Yan; Shu, Bo; Meng, Jin; Zhang, Yuan; Zheng, Caishang; Ke, Xianliang; Gong, Peng; Hu, Qinxue; Wang, Hanzhong

2016-01-01

ABSTRACT Accumulating evidence suggests that viruses hijack cellular proteins to circumvent the host immune system. Ubiquitination and SUMOylation are extensively studied posttranslational modifications (PTMs) that play critical roles in diverse biological processes. Cross talk between ubiquitination and SUMOylation of both host and viral proteins has been reported to result in distinct functional consequences. Enterovirus 71 (EV71), an RNA virus belonging to the family Picornaviridae, is a common cause of hand, foot, and mouth disease. Little is known concerning how host PTM systems interact with enteroviruses. Here, we demonstrate that the 3D protein, an RNA-dependent RNA polymerase (RdRp) of EV71, is modified by small ubiquitin-like modifier 1 (SUMO-1) both during infection and in vitro. Residues K159 and L150/D151/L152 were responsible for 3D SUMOylation as determined by bioinformatics prediction combined with site-directed mutagenesis. Also, primer-dependent polymerase assays indicated that mutation of SUMOylation sites impaired 3D polymerase activity and virus replication. Moreover, 3D is ubiquitinated in a SUMO-dependent manner, and SUMOylation is crucial for 3D stability, which may be due to the interplay between the two PTMs. Importantly, increasing the level of SUMO-1 in EV71-infected cells augmented the SUMOylation and ubiquitination levels of 3D, leading to enhanced replication of EV71. These results together suggested that SUMO and ubiquitin cooperatively regulated EV71 infection, either by SUMO-ubiquitin hybrid chains or by ubiquitin conjugating to the exposed lysine residue through SUMOylation. Our study provides new insight into how a virus utilizes cellular pathways to facilitate its replication. IMPORTANCE Infection with enterovirus 71 (EV71) often causes neurological diseases in children, and EV71 is responsible for the majority of fatalities. Based on a better understanding of interplay between virus and host cell, antiviral drugs against enteroviruses may be developed. As a dynamic cellular process of posttranslational modification, SUMOylation regulates global cellular protein localization, interaction, stability, and enzymatic activity. However, little is known concerning how SUMOylation directly influences virus replication by targeting viral polymerase. Here, we found that EV71 polymerase 3D was SUMOylated during EV71 infection and in vitro. Moreover, the SUMOylation sites were determined, and in vitro polymerase assays indicated that mutations at SUMOylation sites could impair polymerase synthesis. Importantly, 3D is ubiquitinated in a SUMOylation-dependent manner that enhances the stability of the viral polymerase. Our findings indicate that the two modifications likely cooperatively enhance virus replication. Our study may offer a new therapeutic strategy against virus replication. PMID:27630238

Temporal and SUMO-specific SUMOylation contribute to the dynamics of Polo-like kinase 1 (PLK1) and spindle integrity during mouse oocyte meiosis.

PubMed

Feitosa, Weber Beringui; Hwang, KeumSil; Morris, Patricia L

2018-02-15

During mammalian meiosis, Polo-like kinase 1 (PLK1) is essential during cell cycle progression. In oocyte maturation, PLK1 expression is well characterized but timing of posttranslational modifications regulating its activity and subcellular localization are less clear. Small ubiquitin-related modifier (SUMO) posttranslational modifier proteins have been detected in mammalian gametes but their precise function during gametogenesis is largely unknown. In the present paper we report for mouse oocytes that both PLK1 and phosphorylated PLK1 undergo SUMOylation in meiosis II (MII) oocytes using immunocytochemistry, immunoprecipitation and in vitro SUMOylation assays. At MII, PLK1 is phosphorylated at threonine-210 and serine-137. MII oocyte PLK1 and phosphorylated PLK1 undergo SUMOylation by SUMO-1, -2 and -3 as shown by individual in vitro assays. Using these assays, forms of phosphorylated PLK1 normalized to PLK1 increased significantly and correlated with SUMOylated PLK1 levels. During meiotic progression and maturation, SUMO-1-SUMOylation of PLK1 is involved in spindle formation whereas SUMO-2/3-SUMOylation may regulate PLK1 activity at kinetochore-spindle attachment sites. Microtubule integrity is required for PLK1 localization with SUMO-1 but not with SUMO-2/3. Inhibition of SUMOylation disrupts proper meiotic bipolar spindle organization and spindle-kinetochore attachment. The data show that both temporal and SUMO-specific-SUMOylation play important roles in orchestrating functional dynamics of PLK1 during mouse oocyte meiosis, including subcellular compartmentalization. Copyright © 2018 Elsevier Inc. All rights reserved.

Human stanniocalcin-1 interacts with nuclear and cytoplasmic proteins and acts as a SUMO E3 ligase.

PubMed

dos Santos, Marcos Tadeu; Trindade, Daniel Maragno; Gonçalves, Kaliandra de Almeida; Bressan, Gustavo Costa; Anastassopoulos, Filipe; Yunes, José Andres; Kobarg, Jörg

2011-01-01

Human stanniocalcin-1 (STC1) is a glycoprotein that has been implicated in different physiological process, including angiogenesis, apoptosis and carcinogenesis. Here we identified STC1 as a putative molecular marker for the leukemic bone marrow microenvironment and identified new interacting protein partners for STC1. Seven selected interactions retrieved from yeast two-hybrid screens were confirmed by GST-pull down assays in vitro. The N-terminal region was mapped to be the region that mediates the interaction with cytoplasmic, mitochondrial and nuclear proteins. STC1 interacts with SUMO-1 and several proteins that have been shown to be SUMOylated and localized to SUMOylation related nuclear bodies. Although STC1 interacts with SUMO-1 and has a high theoretical prediction score for a SUMOylation site, endogenous co-immunoprecipitation and in vitro SUMOylation assays with the purified recombinant protein could not detect STC1 SUMOylation. However, when we tested STC1 for SUMO E3 ligase activity, we found in an in vitro assay, that it significantly increases the SUMOylation of two other proteins. Confocal microscopic subcellular localization studies using both transfected cells and specific antibodies for endogenous STC1 revealed a cytoplasmic and nuclear deposition, the latter in the form of some specific dot-like substructure resembling SUMOylation related nuclear bodies. Together, these findings suggest a new role for STC1 in SUMOylation pathways, in nuclear bodies.

Cooling-induced SUMOylation of EXOSC10 down-regulates ribosome biogenesis

PubMed Central

Bastide, Amandine; Peretti, Diego; Roobol, Anne; Roobol, Jo; Mallucci, Giovanna R.; Smales, C. Mark; Willis, Anne E.

2016-01-01

The RNA exosome is essential for 3′ processing of functional RNA species and degradation of aberrant RNAs in eukaryotic cells. Recent reports have defined the substrates of the exosome catalytic domains and solved the multimeric structure of the exosome complex. However, regulation of exosome activity remains poorly characterized, especially in response to physiological stress. Following the observation that cooling of mammalian cells results in a reduction in 40S:60S ribosomal subunit ratio, we uncover regulation of the nuclear exosome as a result of reduced temperature. Using human cells and an in vivo model system allowing whole-body cooling, we observe reduced EXOSC10 (hRrp6, Pm/Scl-100) expression in the cold. In parallel, both models of cooling increase global SUMOylation, leading to the identification of specific conjugation of SUMO1 to EXOSC10, a process that is increased by cooling. Furthermore, we define the major SUMOylation sites in EXOSC10 by mutagenesis and show that overexpression of SUMO1 alone is sufficient to suppress EXOSC10 abundance. Reducing EXOSC10 expression by RNAi in human cells correlates with the 3′ preribosomal RNA processing defects seen in the cold as well as reducing the 40S:60S ratio, a previously uncharacterized consequence of EXOSC10 suppression. Together, this work illustrates that EXOSC10 can be modified by SUMOylation and identifies a physiological stress where this regulation is prevalent both in vitro and in vivo. PMID:26857222

Sumoylation of the Epstein-Barr Virus BZLF1 Protein Inhibits Its Transcriptional Activity and Is Regulated by the Virus-Encoded Protein Kinase▿

PubMed Central

Hagemeier, Stacy R.; Dickerson, Sarah J.; Meng, Qiao; Yu, Xianming; Mertz, Janet E.; Kenney, Shannon C.

2010-01-01

The Epstein-Barr virus (EBV) immediate-early protein BZLF1 (Z) mediates the switch between latent and lytic EBV infection. Z not only activates early lytic viral gene transcription but also plays a direct role in lytic viral genome replication. Although a small fraction of Z is known to be sumoylated, the effects of this posttranslational modification on various different Z functions have not been well defined. In this report, we show that only the lysine at amino acid residue 12 is required for the sumoylation of Z, and that Z can be sumoylated by SUMO isoforms 1, 2, and 3. We also demonstrate that the sumo-defective Z mutants ZK12A and ZK12R have enhanced transcriptional activity. The sumoylated and nonsumoylated forms of Z were found to have a similar cellular location, both being localized primarily within the nuclear matrix. The Z sumo-defective mutants were, however, partially defective for disrupting promyelocytic leukemia (PML) bodies compared to the ability of wild-type Z. In addition, we show that lytic viral genome replication does not require the sumoylation of Z, although a Z mutant altered at both amino acids 12 and 13 is replication defective. Furthermore, we show that the sumoylation of Z is greatly increased (from less than 1 to about 11%) in lytically induced 293 cells infected with an EBV mutant virus deleted for the EBV-encoded protein kinase (EBV-PK) compared to that of 293 cells infected with wild-type EBV, and that the overexpression of EBV-PK leads to the reduced sumoylation of Z in EBV-negative cells. Our results suggest that the sumoylation of Z helps to promote viral latency, and that EBV-PK inhibits Z sumoylation during viral reactivation. PMID:20181712

Global analysis of sumoylation function reveals novel insights into development and appressorium-mediated infection of the rice blast fungus.

PubMed

Liu, Caiyun; Li, Zhigang; Xing, Junjie; Yang, Jun; Wang, Zhao; Zhang, Hong; Chen, Deng; Peng, You-Liang; Chen, Xiao-Lin

2018-04-16

Protein post-translational modifications play critical roles in cellular processes, development and stress response. The small ubiquitin-like modifier (SUMO) to proteins is one of the essential modifications in eukaryotes, but its function remains largely unknown in plant pathogenic fungi. We present a comprehensive analysis combined with proteomic, molecular and cellular approaches to explore the roles of sumoylation in the model plant fungal pathogen, Magnaporthe oryzae. We found the SUMO pathway plays key roles in colony growth, conidia formation and virulence to the host, as well as cell-cycle-related phenotypes. Sumoylation is also involved in responding to different stresses. Affinity purification identified 940 putative SUMO substrates, many of which were reported to be involved in development, stress response and infection. Interestingly, four septins were also shown to be sumoylated. Mutation of consensus sumoylation sites in each septin all resulted in reduced virulence to the host and dislocation of septins in appressoria. Moreover, sumoylation is also involved in extracellular secretion of different effector proteins. Our study on the functions of sumoylation provides novel insight into development and infection of the rice blast fungus. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Arsenic degrades PML or PML-RARalpha through a SUMO-triggered RNF4/ubiquitin-mediated pathway.

PubMed

Lallemand-Breitenbach, Valérie; Jeanne, Marion; Benhenda, Shirine; Nasr, Rihab; Lei, Ming; Peres, Laurent; Zhou, Jun; Zhu, Jun; Raught, Brian; de Thé, Hugues

2008-05-01

In acute promyelocytic leukaemia (APL), arsenic trioxide induces degradation of the fusion protein encoded by the PML-RARA oncogene, differentiation of leukaemic cells and produces clinical remissions. SUMOylation of its PML moiety was previously implicated, but the nature of the degradation pathway involved and the role of PML-RARalpha catabolism in the response to therapy have both remained elusive. Here, we demonstrate that arsenic-induced PML SUMOylation triggers its Lys 48-linked polyubiquitination and proteasome-dependent degradation. When exposed to arsenic, SUMOylated PML recruits RNF4, the human orthologue of the yeast SUMO-dependent E3 ubiquitin-ligase, as well as ubiquitin and proteasomes onto PML nuclear bodies. Arsenic-induced differentiation is impaired in cells transformed by a non-degradable PML-RARalpha SUMOylation mutant or in APL cells transduced with a dominant-negative RNF4, directly implicating PML-RARalpha catabolism in the therapeutic response. We thus identify PML as the first protein degraded by SUMO-dependent polyubiquitination. As PML SUMOylation recruits not only RNF4, ubiquitin and proteasomes, but also many SUMOylated proteins onto PML nuclear bodies, these domains could physically integrate the SUMOylation, ubiquitination and degradation pathways.

SUMOylated IRF-1 shows oncogenic potential by mimicking IRF-2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Sun-Mi; School of Biological Sciences and Biotechnology, Chonnam National University, Gwangju 500-757; Chae, Myounghee

2010-01-01

Interferon regulatory factor-1 (IRF-1) is an interferon-induced transcriptional activator that suppresses tumors by impeding cell proliferation. Recently, we demonstrated that the level of SUMOylated IRF-1 is elevated in tumor cells, and that SUMOylation of IRF-1 attenuates its tumor-suppressive function. Here we report that SUMOylated IRF-1 mimics IRF-2, an antagonistic repressor, and shows oncogenic potential. To demonstrate the role of SUMOylated IRF-1 in tumorigenesis, we used SUMO-IRF-1 recombinant protein. Stable expression of SUMO-IRF-1 in NIH3T3 cells resulted in focus formation and anchorage-independent growth in soft agar. Inoculation of SUMO-IRF-1-transfected cells into athymic nude mice resulted in tumor formation and infiltration ofmore » adipose tissues. Finally, we demonstrated that SUMO-IRF-1 transforms NIH3T3 cells in a dose-dependent manner suggesting that SUMOylated IRF-1 may act as an oncogenic protein in tumor cells.« less

TRPV1 SUMOylation regulates nociceptive signaling in models of inflammatory pain.

PubMed

Wang, Yan; Gao, Yingwei; Tian, Quan; Deng, Qi; Wang, Yangbo; Zhou, Tian; Liu, Qiang; Mei, Kaidi; Wang, Yingping; Liu, Huiqing; Ma, Ruining; Ding, Yuqiang; Rong, Weifang; Cheng, Jinke; Yao, Jing; Xu, Tian-Le; Zhu, Michael X; Li, Yong

2018-04-18

Although TRPV1 channels represent a key player of noxious heat sensation, the precise mechanisms for thermal hyperalgesia remain unknown. We report here that conditional knockout of deSUMOylation enzyme, SENP1, in mouse dorsal root ganglion (DRG) neurons exacerbated thermal hyperalgesia in both carrageenan- and Complete Freund's adjuvant-induced inflammation models. TRPV1 is SUMOylated at a C-terminal Lys residue (K822), which specifically enhances the channel sensitivity to stimulation by heat, but not capsaicin, protons or voltage. TRPV1 SUMOylation is decreased by SENP1 but upregulated upon peripheral inflammation. More importantly, the reduced ability of TRPV1 knockout mice to develop inflammatory thermal hyperalgesia was rescued by viral infection of lumbar 3/4 DRG neurons of wild-type TRPV1, but not its SUMOylation-deficient mutant, K822R. These data suggest that TRPV1 SUMOylation is essential for the development of inflammatory thermal hyperalgesia, through a mechanism that involves sensitization of the channel response specifically to thermal stimulation.

System-wide identification of wild-type SUMO-2 conjugation sites

PubMed Central

Hendriks, Ivo A.; D'Souza, Rochelle C.; Chang, Jer-Gung; Mann, Matthias; Vertegaal, Alfred C. O.

2015-01-01

SUMOylation is a reversible post-translational modification (PTM) regulating all nuclear processes. Identification of SUMOylation sites by mass spectrometry (MS) has been hampered by bulky tryptic fragments, which thus far necessitated the use of mutated SUMO. Here we present a SUMO-specific protease-based methodology which circumvents this problem, dubbed Protease-Reliant Identification of SUMO Modification (PRISM). PRISM allows for detection of SUMOylated proteins as well as identification of specific sites of SUMOylation while using wild-type SUMO. The method is generic and could be widely applied to study lysine PTMs. We employ PRISM in combination with high-resolution MS to identify SUMOylation sites from HeLa cells under standard growth conditions and in response to heat shock. We identified 751 wild-type SUMOylation sites on endogenous proteins, including 200 dynamic SUMO sites in response to heat shock. Thus, we have developed a method capable of quantitatively studying wild-type mammalian SUMO at the site-specific and system-wide level. PMID:26073453

Shigella entry unveils a calcium/calpain-dependent mechanism for inhibiting sumoylation

PubMed Central

Lhocine, Nouara; Andrieux, Alexandra; Nigro, Giulia; Mounier, Joëlle

2017-01-01

Disruption of the sumoylation/desumoylation equilibrium is associated with several disease states such as cancer and infections, however the mechanisms regulating the global SUMO balance remain poorly defined. Here, we show that infection by Shigella flexneri, the causative agent of human bacillary dysentery, switches off host sumoylation during epithelial cell infection in vitro and in vivo and that this effect is mainly mediated by a calcium/calpain-induced cleavage of the SUMO E1 enzyme SAE2, thus leading to sumoylation inhibition. Furthermore, we describe a mechanism by which Shigella promotes its own invasion by altering the sumoylation state of RhoGDIα, a master negative regulator of RhoGTPase activity and actin polymerization. Together, our data suggest that SUMO modification is essential to restrain pathogenic bacterial entry by limiting cytoskeletal rearrangement induced by bacterial effectors. Moreover, these findings identify calcium-activated calpains as powerful modulators of cellular sumoylation levels with potentially broad implications in several physiological and pathological situations. PMID:29231810

SUMOylation pathway alteration coupled with downregulation of SUMO E2 enzyme at mucosal epithelium modulates inflammation in inflammatory bowel disease

PubMed Central

Mustfa, Salman Ahmad; Singh, Mukesh; Suhail, Aamir; Mohapatra, Gayatree; Verma, Smriti; Chakravorty, Debangana; Rana, Sarika; Rampal, Ritika; Dhar, Atika; Saha, Sudipto; Ahuja, Vineet

2017-01-01

Post-translational modification pathways such as SUMOylation are integral to all cellular processes and tissue homeostasis. We investigated the possible involvement of SUMOylation in the epithelial signalling in Crohn's disease (CD) and ulcerative colitis (UC), the two major forms of inflammatory bowel disease (IBD). Initially in a murine model of IBD, induced by dextran–sulfate–sodium (DSS mice), we observed inflammation accompanied by a lowering of global SUMOylation of colonic epithelium. The observed SUMOylation alteration was due to a decrease in the sole SUMO E2 enzyme (Ubc9). Mass-spectrometric analysis revealed the existence of a distinct SUMOylome (SUMO-conjugated proteome) in DSS mice with alteration of key cellular regulators, including master kinase Akt1. Knocking-down of Ubc9 in epithelial cells resulted in dramatic activation of inflammatory gene expression, a phenomenon that acted via reduction in Akt1 and its SUMOylated form. Importantly, a strong decrease in Ubc9 and Akt1 was also seen in endoscopic biopsy samples (N = 66) of human CD and UC patients. Furthermore, patients with maximum disease indices were always accompanied by severely lowered Ubc9 or SUMOylated-Akt1. Mucosal tissues with severely compromised Ubc9 function displayed higher levels of pro-inflammatory cytokines and compromised wound-healing markers. Thus, our results reveal an important and previously undescribed role for the SUMOylation pathway involving Ubc9 and Akt1 in modulation of epithelial inflammatory signalling in IBD. PMID:28659381

Impairment of Human Immunodeficiency Virus Type-1 Integrase SUMOylation Correlates with an Early Replication Defect*

PubMed Central

Zamborlini, Alessia; Coiffic, Audrey; Beauclair, Guillaume; Delelis, Olivier; Paris, Joris; Koh, Yashuiro; Magne, Fabian; Giron, Marie-Lou; Tobaly-Tapiero, Joelle; Deprez, Eric; Emiliani, Stephane; Engelman, Alan; de Thé, Hugues; Saïb, Ali

2011-01-01

HIV-1 integrase (IN) orchestrates the integration of the reverse transcribed viral cDNA into the host cell genome and participates also in other steps of HIV-1 replication. Cellular and viral factors assist IN in performing its multiple functions, and post-translational modifications contribute to modulate its activities. Here, we show that HIV-1 IN is modified by SUMO proteins and that phylogenetically conserved SUMOylation consensus motifs represent major SUMO acceptor sites. Viruses harboring SUMOylation site IN mutants displayed a replication defect that was mapped during the early stages of infection, before integration but after reverse transcription. Because SUMOylation-defective IN mutants retained WT catalytic activity, we hypothesize that SUMOylation might regulate the affinity of IN for co-factors, contributing to efficient HIV-1 replication. PMID:21454548

Organization and Regulation of Soybean SUMOylation System under Abiotic Stress Conditions

PubMed Central

Li, Yanjun; Wang, Guixin; Xu, Zeqian; Li, Jing; Sun, Mengwei; Guo, Jingsong; Ji, Wei

2017-01-01

Covalent attachment of the small ubiquitin-related modifier, SUMO, to substrate proteins plays a significant role in plants under stress conditions, which can alter target proteins' function, location, and protein-protein interactions. Despite this importance, information about SUMOylation in the major legume crop, soybean, remains obscure. In this study, we performed a bioinformatics analysis of the entire soybean genome and identified 40 genes belonged to six families involved in a cascade of enzymatic reactions in soybean SUMOylation system. The cis-acting elements analysis revealed that promoters of SUMO pathway genes contained different combinations of stress and development-related cis-regulatory elements. RNA-seq data analysis showed that SUMO pathway components exhibited versatile tissue-specific expression patterns, indicating coordinated functioning during plant growth and development. qRT-PCR analysis of 13 SUMO pathway members indicated that majority of the SUMO pathway members were transcriptionally up-regulated by NaCl, heat and ABA stimuli during the 24 h period of treatment. Furthermore, SUMOylation dynamics in soybean roots under abiotic stress treatment were analyzed by western blot, which were characterized by regulation of SUMOylated proteins. Collectively, this study defined the organization of the soybean SUMOylation system and implied an essential function for SUMOylation in soybean abiotic stress responses. PMID:28878795

Activation of the Slx5–Slx8 Ubiquitin Ligase by Poly-small Ubiquitin-like Modifier Conjugates*S⃞

PubMed Central

Mullen, Janet R.; Brill, Steven J.

2008-01-01

Protein sumoylation is a regulated process that is important for the health of human and yeast cells. In budding yeast, a subset of sumoylated proteins is targeted for ubiquitination by a conserved heterodimeric ubiquitin (Ub) ligase, Slx5–Slx8, which is needed to suppress the accumulation of high molecular weight small ubiquitin-like modifier (SUMO) conjugates. Structure-function analysis indicates that the Slx5–Slx8 complex contains multiple SUMO-binding domains that are collectively required for in vivo function. To determine the specificity of Slx5–Slx8, we assayed its Ub ligase activity using sumoylated Siz2 as an in vitro substrate. In contrast to unsumoylated or multisumoylated Siz2, substrates containing poly-SUMO conjugates were efficiently ubiquitinated by Slx5–Slx8. Although Siz2 itself was ubiquitinated, the bulk of the Ub was conjugated to SUMO residues. Slx5–Slx8 primarily mono-ubiquitinated the N-terminal SUMO moiety of the chain. These data indicate that the Slx5–Slx8 Ub ligase is stimulated by poly-SUMO conjugates and that it can ubiquitinate a poly-SUMO chain. PMID:18499666

Sumoylation Dynamics During Keratinocyte Differentiation

PubMed Central

Deyrieux, Adeline F.; Rosas-Acosta, Germán; Ozbun, Michelle A.; Wilson, Van G.

2012-01-01

Summary SUMO modification regulates the activity of numerous transcription factors that have a direct role in cell cycle progression, apoptosis, cellular proliferation, and development, but its role in differentiation processes is less clear. Keratinocyte differentiation requires the coordinated activation of a series of transcription factors, and as several critical keratinocyte transcription factors are known to be SUMO substrates, we investigated the role of sumoylation in keratinocyte differentiation. In a human keratinocyte cell line model (HaCaT cells), calcium-induced differentiation led to the transient and coordinated transcriptional activation of the genes encoding critical sumoylation system components, including SAE1, SAE2, Ubc9, SENP1, Miz-1 (PIASxβ), SUMO2, and SUMO3. The increased gene expression resulted in higher levels of the respective proteins and changes in the pattern of sumoylated substrate proteins during the differentiation process. Similar to the HaCaT results, stratified human foreskin keratinocytes showed an upregulation of Ubc9 in the suprabasal layers. Lastly, abrogation of sumoylation by Gam1 expression severely disrupted normal HaCaT differentiation, consistent with an important role for sumoylation in the proper progression of this biological process. PMID:17164289

DeSUMOylation switches Kaiso from activator to repressor upon hyperosmotic stress.

PubMed

Zhenilo, Svetlana; Deyev, Igor; Litvinova, Ekaterina; Zhigalova, Nadezhda; Kaplun, Daria; Sokolov, Alexey; Mazur, Alexander; Prokhortchouk, Egor

2018-02-22

Kaiso is a member of the BTB/POZ zinc finger family, which is involved in cancer progression, cell cycle control, apoptosis, and WNT signaling. Depending on promoter context, it may function as either a transcriptional repressor or activator. Previous studies found that Kaiso might be SUMOylated due to heat shock, but the biological significance of Kaiso SUMOylation is unclear. Here, we find that K42 is the only amino acid within Kaiso that is modified with SUMO. Kaiso is monoSUMOylated at lysine 42 in cell lines of kidney origin under normal physiological conditions. SUMOylated Kaiso can activate transcription from exogenous methylated promoters, wherein the deSUMOylated form of the protein kept the ability to be a repressor. Rapid Kaiso deSUMOylation occurs in response to hyperosmotic stress and is reversible upon return to an isotonic environment. DeSUMOylation occurs within minutes in HEK293 cells treated with 100 mM NaCl and relaxes in 3 h even in a salt-containing medium. Genomic editing of Kaiso by conversion of K42 into R42 (K42R) in HEK293 cells that resulted in fully deSUMOylated endogenous protein led to misregulation of genes associated with ion transport, blood pressure, and the immune response. TRIM25 was significantly repressed in two K42R HEK293 clones. By a series of rescue experiments with K42R and KO HEK293 cells, we show that TRIM25 is a direct transcriptional target for Kaiso. In the absence of Kaiso, the level of TRIM25 is insensitive to hyperosmotic stress. Extending our observations to animal models, we show that in response to a high salt diet, Kaiso knockout mice are characterized by significantly higher blood pressure increases when compared to wild-type animals. Thus, we propose a novel biological role for Kaiso in the regulation of homeostasis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishida, Tamotsu, E-mail: nishida@gene.mie-u.ac.jp; Yamada, Yoshiji

Parkin-interacting substrate (PARIS), a member of the family of Krüppel-associated box (KRAB)-containing zinc-finger transcription factors, is a substrate of the ubiquitin E3 ligase parkin. PARIS represses the expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), although the underlying mechanisms remain largely unknown. In the present study, we demonstrate that PARIS can be SUMOylated, and its SUMOylation plays a role in the repression of PGC-1a promoter activity. Protein inhibitor of activated STAT y (PIASy) was identified as an interacting protein of PARIS and shown to enhance its SUMOylation. PIASy repressed PGC-1a promoter activity, and this effect was attenuated by PARIS inmore » a manner dependent on its SUMOylation status. Co-expression of SUMO-1 with PIASy completely repressed PGC-1a promoter activity independently of PARIS expression. PARIS-mediated PGC-1a promoter repression depended on the activity of histone deacetylases (HDAC), whereas PIASy repressed the PGC-1a promoter in an HDAC-independent manner. Taken together, these results suggest that PARIS and PIASy modulate PGC-1a gene transcription through distinct molecular mechanisms. -- Highlights: •PARIS can be SUMOylated in vivo and in vitro. •SUMOylation of PARIS functions in the repression of PGC-1a promoter activity. •PIASy interacts with PARIS and enhances its SUMOylation. •PIASy influences PARIS-mediated repression of PGC-1a promoter activity.« less

Sumoylation of the Basic Helix-Loop-Helix Transcription Factor Sharp-1 Regulates Recruitment of the Histone Methyltransferase G9a and Function in Myogenesis*

PubMed Central

Wang, Yaju; Shankar, Shilpa Rani; Kher, Devaki; Ling, Belinda Mei Tze; Taneja, Reshma

2013-01-01

Sumoylation is an important post-translational modification that alters the activity of many transcription factors. However, the mechanisms that link sumoylation to alterations in chromatin structure, which culminate in tissue specific gene expression, are not fully understood. In this study, we demonstrate that SUMO modification of the transcription factor Sharp-1 is required for its full transcriptional repression activity and function as an inhibitor of skeletal muscle differentiation. Sharp-1 is modified by sumoylation at two conserved lysine residues 240 and 255. Mutation of these SUMO acceptor sites in Sharp-1 does not impact its subcellular localization but attenuates its ability to act as a transcriptional repressor and inhibit myogenic differentiation. Consistently, co-expression of the SUMO protease SENP1 with wild type Sharp-1 abrogates Sharp-1-dependent inhibition of myogenesis. Interestingly, sumoylation acts as a signal for recruitment of the co-repressor G9a. Thus, enrichment of G9a, and histone H3 lysine 9 dimethylation (H3K9me2), a signature of G9a activity, is dramatically reduced at muscle promoters in cells expressing sumoylation-defective Sharp-1. Our findings demonstrate how sumoylation of Sharp-1 exerts an impact on chromatin structure and transcriptional repression of muscle gene expression through recruitment of G9a. PMID:23637228

Identification of Sumoylated Proteins in the Silkworm Bombyx mori

PubMed Central

Tang, Xudong; Fu, Xuliang; Hao, Bifang; Zhu, Feng; Xiao, Shengyan; Xu, Li; Shen, Zhongyuan

2014-01-01

Small ubiquitin-like modifier (SUMO) modification (SUMOylation) is an important and widely used reversible modification system in eukaryotic cells. It regulates various cell processes, including protein targeting, transcriptional regulation, signal transduction, and cell division. To understand its role in the model lepidoptera insect Bombyx mori, a recombinant baculovirus was constructed to express an enhanced green fluorescent protein (eGFP)-SUMO fusion protein along with ubiquitin carrier protein 9 of Bombyx mori (BmUBC9). SUMOylation substrates from Bombyx mori cells infected with this baculovirus were isolated by immunoprecipitation and identified by LC–ESI-MS/MS. A total of 68 candidate SUMOylated proteins were identified, of which 59 proteins were functionally categorized to gene ontology (GO) terms. Analysis of kyoto encyclopedia of genes and genomes (KEGG) pathways showed that 46 of the identified proteins were involved in 76 pathways that mainly play a role in metabolism, spliceosome and ribosome functions, and in RNA transport. Furthermore, SUMOylation of four candidates (polyubiquitin-C-like isoform X1, 3-hydroxyacyl-CoA dehydrogenase, cyclin-related protein FAM58A-like and GTP-binding nuclear protein Ran) were verified by co-immunoprecipitation in Drosophila schneide 2 cells. In addition, 74% of the identified proteins were predicted to have at least one SUMOylation site. The data presented here shed light on the crucial process of protein sumoylation in Bombyx mori. PMID:25470021

Sumoylation of the Tumor Suppressor Promyelocytic Leukemia Protein Regulates Arsenic Trioxide-Induced Collagen Synthesis in Osteoblasts.

PubMed

Xu, Wen-Xiao; Liu, Sheng-Zhi; Wu, Di; Qiao, Guo-Fen; Yan, Jinglong

2015-01-01

Promyelocytic leukemia (PML) protein is a tumor suppressor that fuses with retinoic acid receptor-α (PML-RARα) to contribute to the initiation of acute promyelocytic leukemia (APL). Arsenic trioxide (ATO) upregulates expression of TGF-β1, promoting collagen synthesis in osteoblasts, and ATO binds directly to PML to induce oligomerization, sumoylation, and ubiquitination. However, how ATO upregulates TGF-β1 expression is uncertain. Thus, we suggested that PML sumoylation is responsible for regulation of TGF-β1 protein expression. Kunming mice were treated with ATO, and osteoblasts were counted under scanning electron microscopy. Masson's staining was used to quantify collagen content. hFOB1.19 cells were transfected with siRNA against UBC9 or RNF4, and then treated with ATO or FBS. TGF-β1, PML expression, and sumoylation were quantified with Western blot, and collagen quantified via immunocytochemistry. ATO enhanced osteoblast accumulation, collagen synthesis, and PML-NB formation in vivo. Knocking down UBC9 in hFOB1.19 cells inhibited ATO- and FBS-induced PML sumoylation, TGF-β1 expression, and collagen synthesis. Conversely, knocking down RNF4 enhanced ATO- and FBS-induced PML sumoylation, TGF-β1 expression, and collagen synthesis. These data suggest that PML sumoylation is required for ATO-induced collagen synthesis in osteoblasts. © 2015 S. Karger AG, Basel.

A high throughput mutagenic analysis of yeast sumo structure and function

PubMed Central

Newman, Heather A.; Lu, Jian; Carson, Caryn; Boeke, Jef D.

2017-01-01

Sumoylation regulates a wide range of essential cellular functions through diverse mechanisms that remain to be fully understood. Using S. cerevisiae, a model organism with a single essential SUMO gene (SMT3), we developed a library of >250 mutant strains with single or multiple amino acid substitutions of surface or core residues in the Smt3 protein. By screening this library using plate-based assays, we have generated a comprehensive structure-function based map of Smt3, revealing essential amino acid residues and residues critical for function under a variety of genotoxic and proteotoxic stress conditions. Functionally important residues mapped to surfaces affecting Smt3 precursor processing and deconjugation from protein substrates, covalent conjugation to protein substrates, and non-covalent interactions with E3 ligases and downstream effector proteins containing SUMO-interacting motifs. Lysine residues potentially involved in formation of polymeric chains were also investigated, revealing critical roles for polymeric chains, but redundancy in specific chain linkages. Collectively, our findings provide important insights into the molecular basis of signaling through sumoylation. Moreover, the library of Smt3 mutants represents a valuable resource for further exploring the functions of sumoylation in cellular stress response and other SUMO-dependent pathways. PMID:28166236

SUMOylation-disrupting WAS mutation converts WASp from a transcriptional activator to a repressor of NF-κB response genes in T cells.

PubMed

Sarkar, Koustav; Sadhukhan, Sanjoy; Han, Seong-Su; Vyas, Yatin M

2015-10-01

In Wiskott-Aldrich syndrome (WAS), immunodeficiency and autoimmunity often comanifest, yet how WAS mutations misregulate chromatin-signaling in Thelper (TH) cells favoring development of auto-inflammation over protective immunity is unclear. Previously, we identified an essential promoter-specific, coactivator role of nuclear-WASp in TH1 gene transcription. Here we identify small ubiquitin-related modifier (SUMO)ylation as a novel posttranslational modification of WASp, impairment of which converts nuclear-WASp from a transcriptional coactivator to a corepressor of nuclear factor (NF)-κB response genes in human (TH)1-differentiating cells. V75M, one of many disease-causing mutations occurring in SUMO*motif (72-ψψψψKDxxxxSY-83) of WASp, compromises WASp-SUMOylation, associates with COMMD1 to attenuate NF-κB signaling, and recruits histone deacetylases-6 (HDAC6) to p300-marked promoters of NF-κB response genes that pattern immunity but not inflammation. Consequently, proteins mediating adaptive immunity (IFNG, STAT1, TLR1) are deficient, whereas those mediating auto-inflammation (GM-CSF, TNFAIP2, IL-1β) are paradoxically increased in TH1 cells expressing SUMOylation-deficient WASp. Moreover, SUMOylation-deficient WASp favors ectopic development of the TH17-like phenotype (↑IL17A, IL21, IL22, IL23R, RORC, and CSF2) under TH1-skewing conditions, suggesting a role for WASp in modulating TH1/TH17 plasticity. Notably, pan-histone deacetylase inhibitors lift promoter-specific repression imposed by SUMOylation-deficient WASp and restore misregulated gene expression. Our findings uncovering a SUMOylation-based mechanism controlling WASp's dichotomous roles in transcription may have implications for personalized therapy for patients carrying mutations that perturb WASp-SUMOylation. © 2015 by The American Society of Hematology.

A new MCM modification cycle regulates DNA replication initiation

PubMed Central

Wei, Lei; Zhao, Xiaolan

2016-01-01

The MCM DNA helicase is a central regulatory target during genome replication. MCM is kept inactive during G1 and activated in S phase to initiate replication. During this transition, the only known chemical change on MCM is the gain of multi-site phosphorylation that promotes cofactor recruitment. As replication initiation is intimately linked to multiple biological cues, additional changes on MCM can provide further regulatory points. Here, we describe a yeast MCM sumoylation cycle that negatively regulates replication. MCM subunits undergo sumoylation upon loading at origins in G1 prior to MCM phosphorylation. MCM sumoylation levels then decline as MCM phosphorylation levels rise, suggesting an inhibitory role in replication. Indeed, increasing MCM sumoylation impairs replication initiation through promoting the recruitment of a phosphatase that reduces MCM phosphorylation and activation. MCM sumoylation thus counterbalances kinase-based regulation to ensure accurate control of replication initiation. PMID:26854664

Overexpression of SKI Oncoprotein Leads to p53 Degradation through Regulation of MDM2 Protein Sumoylation*

PubMed Central

Ding, Boxiao; Sun, Yin; Huang, Jiaoti

2012-01-01

Protooncogene Ski was identified based on its ability to transform avian fibroblasts in vitro. In support of its oncogenic activity, SKI was found to be overexpressed in a variety of human cancers, although the exact molecular mechanism(s) responsible for its oncogenic activity is not fully understood. We found that SKI can negatively regulate p53 by decreasing its level through up-regulation of MDM2 activity, which is mediated by the ability of SKI to enhance sumoylation of MDM2. This stimulation of MDM2 sumoylation is accomplished through a direct interaction of SKI with SUMO-conjugating enzyme E2, Ubc9, resulting in enhanced thioester bond formation and mono-sumoylation of Ubc9. A mutant SKI defective in transformation fails to increase p53 ubiquitination and is unable to increase MDM2 levels and to increase mono-sumoylation of Ubc9, suggesting that the ability of SKI to enhance Ubc9 activity is essential for its transforming function. These results established a detailed molecular mechanism that underlies the ability of SKI to cause cellular transformation while unraveling a novel connection between sumoylation and tumorigenesis, providing potential new therapeutic targets for cancer. PMID:22411991

SUMOylation of phytochrome-B negatively regulates light-induced signaling in Arabidopsis thaliana

PubMed Central

Sadanandom, Ari; Ádám, Éva; Orosa, Beatriz; Viczián, András; Klose, Cornelia; Zhang, Cunjin; Josse, Eve-Marie; Kozma-Bognár, László; Nagy, Ferenc

2015-01-01

The red/far red light absorbing photoreceptor phytochrome-B (phyB) cycles between the biologically inactive (Pr, λmax, 660 nm) and active (Pfr; λmax, 730 nm) forms and functions as a light quality and quantity controlled switch to regulate photomorphogenesis in Arabidopsis. At the molecular level, phyB interacts in a conformation-dependent fashion with a battery of downstream regulatory proteins, including PHYTOCHROME INTERACTING FACTOR transcription factors, and by modulating their activity/abundance, it alters expression patterns of genes underlying photomorphogenesis. Here we report that the small ubiquitin-like modifier (SUMO) is conjugated (SUMOylation) to the C terminus of phyB; the accumulation of SUMOylated phyB is enhanced by red light and displays a diurnal pattern in plants grown under light/dark cycles. Our data demonstrate that (i) transgenic plants expressing the mutant phyBLys996Arg-YFP photoreceptor are hypersensitive to red light, (ii) light-induced SUMOylation of the mutant phyB is drastically decreased compared with phyB-YFP, and (iii) SUMOylation of phyB inhibits binding of PHYTOCHROME INTERACTING FACTOR 5 to phyB Pfr. In addition, we show that OVERLY TOLERANT TO SALT 1 (OTS1) de-SUMOylates phyB in vitro, it interacts with phyB in vivo, and the ots1/ots2 mutant is hyposensitive to red light. Taken together, we conclude that SUMOylation of phyB negatively regulates light signaling and it is mediated, at least partly, by the action of OTS SUMO proteases. PMID:26283376

Ubiquitination and sumoylation of the HTLV-2 Tax-2B protein regulate its NF-κB activity: a comparative study with the HTLV-1 Tax-1 protein

PubMed Central

2012-01-01

Background Retroviruses HTLV-1 and HTLV-2 have homologous genomic structures but differ significantly in pathogenicity. HTLV-1 is associated with Adult T cell Leukemia (ATL), whereas infection by HTLV-2 has no association with neoplasia. Transformation of T lymphocytes by HTLV-1 is linked to the capacity of its oncoprotein Tax-1 to alter cell survival and cell cycle control mechanisms. Among these functions, Tax-1-mediated activation of cellular gene expression via the NF-κB pathway depends on Tax-1 post-translational modifications by ubiquitination and sumoylation. The Tax-2 protein of HTLV-2B (Tax-2B) is also modified by ubiquitination and sumoylation and activates the NF-κB pathway to a level similar to that of Tax-1. The present study aims to understand whether ubiquitination and sumoylation modifications are involved in Tax-2B-mediated activation of the NF-κB pathway. Results The comparison of Tax-1 and Tax-2B lysine to arginine substitution mutants revealed conserved patterns and levels of ubiquitination with notable difference in the lysine usage for sumoylation. Neither Tax-1 nor Tax-2B ubiquitination and sumoylation deficient mutants could activate the NF-κB pathway and fusion of ubiquitin or SUMO-1 to the C-terminus of the ubiquitination and sumoylation deficient Tax-2B mutant strikingly restored transcriptional activity. In addition, ubiquitinated forms of Tax-2B colocalized with RelA and IKKγ in prominent cytoplasmic structures associated with the Golgi apparatus, whereas colocalization of Tax-2B with the RelA subunit of NF-κB and the transcriptional coactivator p300 in punctate nuclear structures was dependent on Tax-2B sumoylation, as previously observed for Tax-1. Conclusions Both Tax-1 and Tax-2 activate the NF-κB pathway via similar mechanisms involving ubiquitination and sumoylation. Therefore, the different transforming potential of HTLV-1 and HTLV-2 is unlikely to be related to different modes of activation of the canonical NF-κB pathway. PMID:23217160

SUMO-Modified FADD Recruits Cytosolic Drp1 and Caspase-10 to Mitochondria for Regulated Necrosis.

PubMed

Choi, Seon-Guk; Kim, Hyunjoo; Jeong, Eun Il; Lee, Ho-June; Park, Sungwoo; Lee, Song-Yi; Lee, Hyeon-Jeong; Lee, Seong Won; Chung, Chin Ha; Jung, Yong-Keun

2017-01-15

Fas-associated protein with death domain (FADD) plays a key role in extrinsic apoptosis. Here, we show that FADD is SUMOylated as an essential step during intrinsic necrosis. FADD was modified at multiple lysine residues (K120/125/149) by small ubiquitin-related modifier 2 (SUMO2) during necrosis caused by calcium ionophore A23187 and by ischemic damage. SUMOylated FADD bound to dynamin-related protein 1 (Drp1) in cells both in vitro and in ischemic tissue damage cores, thus promoting Drp1 recruitment by mitochondrial fission factor (Mff) to accomplish mitochondrial fragmentation. Mitochondrial-fragmentation-associated necrosis was blocked by FADD or Drp1 deficiency and SUMO-defective FADD expression. Interestingly, caspase-10, but not caspase-8, formed a ternary protein complex with SUMO-FADD/Drp1 on the mitochondria upon exposure to A23187 and potentiated Drp1 oligomerization for necrosis. Moreover, the caspase-10 L285F and A414V mutants, found in autoimmune lymphoproliferative syndrome and non-Hodgkin lymphoma, respectively, regulated this necrosis. Our study reveals an essential role of SUMOylated FADD in Drp1- and caspase-10-dependent necrosis, providing insights into the mechanism of regulated necrosis by calcium overload and ischemic injury. Copyright © 2017 American Society for Microbiology.

SUMO-Modified FADD Recruits Cytosolic Drp1 and Caspase-10 to Mitochondria for Regulated Necrosis

PubMed Central

Choi, Seon-Guk; Kim, Hyunjoo; Jeong, Eun Il; Lee, Ho-June; Park, Sungwoo; Lee, Song-Yi; Lee, Hyeon-Jeong; Lee, Seong Won; Chung, Chin Ha

2016-01-01

ABSTRACT Fas-associated protein with death domain (FADD) plays a key role in extrinsic apoptosis. Here, we show that FADD is SUMOylated as an essential step during intrinsic necrosis. FADD was modified at multiple lysine residues (K120/125/149) by small ubiquitin-related modifier 2 (SUMO2) during necrosis caused by calcium ionophore A23187 and by ischemic damage. SUMOylated FADD bound to dynamin-related protein 1 (Drp1) in cells both in vitro and in ischemic tissue damage cores, thus promoting Drp1 recruitment by mitochondrial fission factor (Mff) to accomplish mitochondrial fragmentation. Mitochondrial-fragmentation-associated necrosis was blocked by FADD or Drp1 deficiency and SUMO-defective FADD expression. Interestingly, caspase-10, but not caspase-8, formed a ternary protein complex with SUMO-FADD/Drp1 on the mitochondria upon exposure to A23187 and potentiated Drp1 oligomerization for necrosis. Moreover, the caspase-10 L285F and A414V mutants, found in autoimmune lymphoproliferative syndrome and non-Hodgkin lymphoma, respectively, regulated this necrosis. Our study reveals an essential role of SUMOylated FADD in Drp1- and caspase-10-dependent necrosis, providing insights into the mechanism of regulated necrosis by calcium overload and ischemic injury. PMID:27799292

Sumoylation Modulates the Activity of Spalt-like Proteins during Wing Development in Drosophila*

PubMed Central

Sánchez, Jonatan; Talamillo, Ana; Lopitz-Otsoa, Fernando; Pérez, Coralia; Hjerpe, Roland; Sutherland, James D.; Herboso, Leire; Rodríguez, Manuel S.; Barrio, Rosa

2010-01-01

The Spalt-like family of zinc finger transcription factors is conserved throughout evolution and is involved in fundamental processes during development and during embryonic stem cell maintenance. Although human SALL1 is modified by SUMO-1 in vitro, it is not known whether this post-translational modification plays a role in regulating the activity of this family of transcription factors. Here, we show that the Drosophila Spalt transcription factors are modified by sumoylation. This modification influences their nuclear localization and capacity to induce vein formation through the regulation of target genes during wing development. Furthermore, spalt genes interact genetically with the sumoylation machinery to repress vein formation in intervein regions and to attain the wing final size. Our results suggest a new level of regulation of Sall activity in vivo during animal development through post-translational modification by sumoylation. The evolutionary conservation of this family of transcription factors suggests a functional role for sumoylation in vertebrate Sall members. PMID:20562097

Smad4 SUMOylation is essential for memory formation through upregulation of the skeletal myopathy gene TPM2.

PubMed

Hsu, Wei L; Ma, Yun L; Liu, Yen C; Lee, Eminy H Y

2017-11-28

Smad4 is a critical effector of TGF-β signaling that regulates a variety of cellular functions. However, its role in the brain has rarely been studied. Here, we examined the molecular mechanisms underlying the post-translational regulation of Smad4 function by SUMOylation, and its role in spatial memory formation. In the hippocampus, Smad4 is SUMOylated by the E3 ligase PIAS1 at Lys-113 and Lys-159. Both spatial training and NMDA injection enhanced Smad4 SUMOylation. Inhibition of Smad4 SUMOylation impaired spatial learning and memory in rats by downregulating TPM2, a gene associated with skeletal myopathies. Similarly, knockdown of TPM2 expression impaired spatial learning and memory, while TPM2 mRNA and protein expression increased after spatial training. Among the TPM2 mutations associated with skeletal myopathies, the TPM2E122K mutation was found to reduce TPM2 expression and impair spatial learning and memory in rats. We have identified a novel role of Smad4 SUMOylation and TPM2 in learning and memory formation. These results suggest that patients with skeletal myopathies who carry the TPM2E122K mutation may also have deficits in learning and memory functions.

RUNX family members are covalently modified and regulated by PIAS1-mediated sumoylation

PubMed Central

Kim, J-H; Jang, J-W; Lee, Y-S; Lee, J-W; Chi, X-Z; Li, Y-H; Kim, M-K; Kim, D-M; Choi, B-S; Kim, J; Kim, H-M; van Wijnen, A; Park, IlY; Bae, S-C

2014-01-01

Transcription factors of the RUNX family (RUNXs), which play pivotal roles in normal development and neoplasia, are regulated by various post-translational modifications. To understand the molecular mechanisms underlying the regulation of RUNXs, we performed a large-scale functional genetic screen of a fly mutant library. The screen identified dPias (the fly ortholog of mammalian PIASs), an E3 ligase for the SUMO (small ubiquitin-like modifier) modification, as a novel genetic modifier of lz (the fly ortholog of mammalian RUNX3). Molecular biological analysis revealed that lz/RUNXs are sumoylated by dPias/PIAS1 at an evolutionarily conserved lysine residue (K372 of lz, K144 of RUNX1, K181 of RUNX2 and K148 of RUNX3). PIAS1-mediated sumoylation inhibited RUNX3 transactivation activity, and this modification was promoted by the AKT1 kinase. Importantly, PIAS1 failed to sumoylate some RUNX1 mutants associated with breast cancer. In nude mice, tumorigenicity was promoted by RUNX3 bearing a mutation in the sumoylation site, but suppressed by wild-type RUNX3. Our results suggest that RUNXs are sumoylated by PIAS1, and that this modification could play a critical role in the regulation of the tumor-suppressive activity of these proteins. PMID:24777122

Sumoylation in p27kip1 via RanBP2 promotes cancer cell growth in cholangiocarcinoma cell line QBC939.

PubMed

Yang, Jun; Liu, Yan; Wang, Bing; Lan, Hongzhen; Liu, Ying; Chen, Fei; Zhang, Ju; Luo, Jian

2017-09-07

Cholangiocarcinoma is one of the deadly disease with poor 5-year survival and poor response to conventional therapies. Previously, we found that p27kip1 nuclear-cytoplasmic translocation confers proliferation potential to cholangiocarcinoma cell line QBC939 and this process is mediated by crm-1. However, no other post-transcriptional regulation was found in this process including sumoylation in cholangiocarcinoma. In this study, we explored the role of sumoylation in the nuclear-cytoplasmic translocation of p27kip1 and its involvement of QBC939 cells' proliferation. First, we identified K73 as the sumoylation site in p27kip1. By utilizing plasmid flag-p27kip1, HA-RanBP2, GST-RanBP2 and His-p27kip1 and immunoprecipitation assay, we validated that p27kip1 can serve as the sumoylation target of RanBP2 in QBC939. Furthermore, we confirmed crm-1's role in promoting nuclear-cytoplasmic translocation of p27kip1 and found that RanBP2's function relies on crm-1. However, K73R mutated p27kip1 can't be identified by crm-1 or RanBP2 in p27kip1 translocation process, suggesting sumoylation of p27kip1 via K73 site is necessary in this process by RanBP2 and crm-1. Phenotypically, the overexpression of either RanBP2 or crm-1 can partially rescue the anti-proliferative effect brought by p27kip1 overexpression in both the MTS and EdU assay. For the first time, we identified and validated the K73 sumoylation site in p27kip1, which is critical to RanBP2 and crm-1 in p27kip1 nuclear-cytoplasmic translocation process. Taken together, targeted inhibition of sumoylation of p27kip1 may serve as a potentially potent therapeutic target in the eradication of cholangiocarcinoma development and relapses.

The language-related transcription factor FOXP2 is post-translationally modified with small ubiquitin-like modifiers.

PubMed

Estruch, Sara B; Graham, Sarah A; Deriziotis, Pelagia; Fisher, Simon E

2016-02-12

Mutations affecting the transcription factor FOXP2 cause a rare form of severe speech and language disorder. Although it is clear that sufficient FOXP2 expression is crucial for normal brain development, little is known about how this transcription factor is regulated. To investigate post-translational mechanisms for FOXP2 regulation, we searched for protein interaction partners of FOXP2, and identified members of the PIAS family as novel FOXP2 interactors. PIAS proteins mediate post-translational modification of a range of target proteins with small ubiquitin-like modifiers (SUMOs). We found that FOXP2 can be modified with all three human SUMO proteins and that PIAS1 promotes this process. An aetiological FOXP2 mutation found in a family with speech and language disorder markedly reduced FOXP2 SUMOylation. We demonstrate that FOXP2 is SUMOylated at a single major site, which is conserved in all FOXP2 vertebrate orthologues and in the paralogues FOXP1 and FOXP4. Abolishing this site did not lead to detectable changes in FOXP2 subcellular localization, stability, dimerization or transcriptional repression in cellular assays, but the conservation of this site suggests a potential role for SUMOylation in regulating FOXP2 activity in vivo.

The language-related transcription factor FOXP2 is post-translationally modified with small ubiquitin-like modifiers

PubMed Central

Estruch, Sara B.; Graham, Sarah A.; Deriziotis, Pelagia; Fisher, Simon E.

2016-01-01

Mutations affecting the transcription factor FOXP2 cause a rare form of severe speech and language disorder. Although it is clear that sufficient FOXP2 expression is crucial for normal brain development, little is known about how this transcription factor is regulated. To investigate post-translational mechanisms for FOXP2 regulation, we searched for protein interaction partners of FOXP2, and identified members of the PIAS family as novel FOXP2 interactors. PIAS proteins mediate post-translational modification of a range of target proteins with small ubiquitin-like modifiers (SUMOs). We found that FOXP2 can be modified with all three human SUMO proteins and that PIAS1 promotes this process. An aetiological FOXP2 mutation found in a family with speech and language disorder markedly reduced FOXP2 SUMOylation. We demonstrate that FOXP2 is SUMOylated at a single major site, which is conserved in all FOXP2 vertebrate orthologues and in the paralogues FOXP1 and FOXP4. Abolishing this site did not lead to detectable changes in FOXP2 subcellular localization, stability, dimerization or transcriptional repression in cellular assays, but the conservation of this site suggests a potential role for SUMOylation in regulating FOXP2 activity in vivo. PMID:26867680

LMP1-Induced Sumoylation Influences the Maintenance of Epstein-Barr Virus Latency through KAP1

PubMed Central

Moss, Charles Randall; Whitehurst, Christopher B.; Moody, Cary A.

2015-01-01

ABSTRACT As a herpesvirus, Epstein-Barr virus (EBV) establishes a latent infection that can periodically undergo reactivation, resulting in lytic replication and the production of new infectious virus. Latent membrane protein-1 (LMP1), the principal viral oncoprotein, is a latency-associated protein implicated in regulating viral reactivation and the maintenance of latency. We recently found that LMP1 hijacks the SUMO-conjugating enzyme Ubc9 via its C-terminal activating region-3 (CTAR3) and induces the sumoylation of cellular proteins. Because protein sumoylation can promote transcriptional repression, we hypothesized that LMP1-induced protein sumoylation induces the repression of EBV lytic promoters and helps maintain the viral genome in its latent state. We now show that with inhibition of LMP1-induced protein sumoylation, the latent state becomes less stable or leakier in EBV-transformed lymphoblastoid cell lines. The cells are also more sensitive to viral reactivation induced by irradiation, which results in the increased production and release of infectious virus, as well as increased susceptibility to ganciclovir treatment. We have identified a target of LMP1-mediated sumoylation that contributes to the maintenance of latency in this context: KRAB-associated protein-1 (KAP1). LMP1 CTAR3-mediated sumoylation regulates the function of KAP1. KAP1 also binds to EBV OriLyt and immediate early promoters in a CTAR3-dependent manner, and inhibition of sumoylation processes abrogates the binding of KAP1 to these promoters. These data provide an additional line of evidence that supports our findings that CTAR3 is a distinct functioning regulatory region of LMP1 and confirm that LMP1-induced sumoylation may help stabilize the maintenance of EBV latency. IMPORTANCE Epstein-Barr virus (EBV) latent membrane protein-1 (LMP1) plays an important role in the maintenance of viral latency. Previously, we documented that LMP1 targets cellular proteins to be modified by a ubiquitin-like protein (SUMO). We have now identified a function for this LMP1-induced modification of cellular proteins in the maintenance of EBV latency. Because latently infected cells have to undergo viral reactivation in order to be vulnerable to antiviral drugs, these findings identify a new way to increase the rate of EBV reactivation, which increases cell susceptibility to antiviral therapies. PMID:25948750

A Novel Proteomics Approach to Identify SUMOylated Proteins and Their Modification Sites in Human Cells*

PubMed Central

Galisson, Frederic; Mahrouche, Louiza; Courcelles, Mathieu; Bonneil, Eric; Meloche, Sylvain; Chelbi-Alix, Mounira K.; Thibault, Pierre

2011-01-01

The small ubiquitin-related modifier (SUMO) is a small group of proteins that are reversibly attached to protein substrates to modify their functions. The large scale identification of protein SUMOylation and their modification sites in mammalian cells represents a significant challenge because of the relatively small number of in vivo substrates and the dynamic nature of this modification. We report here a novel proteomics approach to selectively enrich and identify SUMO conjugates from human cells. We stably expressed different SUMO paralogs in HEK293 cells, each containing a His6 tag and a strategically located tryptic cleavage site at the C terminus to facilitate the recovery and identification of SUMOylated peptides by affinity enrichment and mass spectrometry. Tryptic peptides with short SUMO remnants offer significant advantages in large scale SUMOylome experiments including the generation of paralog-specific fragment ions following CID and ETD activation, and the identification of modified peptides using conventional database search engines such as Mascot. We identified 205 unique protein substrates together with 17 precise SUMOylation sites present in 12 SUMO protein conjugates including three new sites (Lys-380, Lys-400, and Lys-497) on the protein promyelocytic leukemia. Label-free quantitative proteomics analyses on purified nuclear extracts from untreated and arsenic trioxide-treated cells revealed that all identified SUMOylated sites of promyelocytic leukemia were differentially SUMOylated upon stimulation. PMID:21098080

The gap junction channel protein connexin 43 is covalently modified and regulated by SUMOylation.

PubMed

Kjenseth, Ane; Fykerud, Tone A; Sirnes, Solveig; Bruun, Jarle; Yohannes, Zeremariam; Kolberg, Matthias; Omori, Yasufumi; Rivedal, Edgar; Leithe, Edward

2012-05-04

SUMOylation is a posttranslational modification in which a member of the small ubiquitin-like modifier (SUMO) family of proteins is conjugated to lysine residues in specific target proteins. Most known SUMOylation target proteins are located in the nucleus, but there is increasing evidence that SUMO may also be a key determinant of many extranuclear processes. Gap junctions consist of arrays of intercellular channels that provide direct transfer of ions and small molecules between adjacent cells. Gap junction channels are formed by integral membrane proteins called connexins, of which the best-studied isoform is connexin 43 (Cx43). Here we show that Cx43 is posttranslationally modified by SUMOylation. The data suggest that the SUMO system regulates the Cx43 protein level and the level of functional Cx43 gap junctions at the plasma membrane. Cx43 was found to be modified by SUMO-1, -2, and -3. Evidence is provided that the membrane-proximal lysines at positions 144 and 237, located in the Cx43 intracellular loop and C-terminal tail, respectively, act as SUMO conjugation sites. Mutations of lysine 144 or lysine 237 resulted in reduced Cx43 SUMOylation and reduced Cx43 protein and gap junction levels. Altogether, these data identify Cx43 as a SUMOylation target protein and represent the first evidence that gap junctions are regulated by the SUMO system.

Senp2 regulates adipose lipid storage by de-SUMOylation of Setdb1.

PubMed

Zheng, Quan; Cao, Ying; Chen, Yalan; Wang, Jiqiu; Fan, Qiuju; Huang, Xian; Wang, Yiping; Wang, Tianshi; Wang, Xiuzhi; Ma, Jiao; Cheng, Jinke

2018-06-01

One major function of adipocytes is to store excess energy in the form of triglycerides. Insufficient adipose lipid storage is associated with many pathological conditions including hyperlipidemia, insulin resistance, and type 2 diabetes. In this study, we observed the overexpression of SUMO-specific protease 2 (Senp2) in adipose tissues during obesity. Adipocyte Senp2 deficiency resulted in less adipose lipid storage accompanied by an ectopic fat accumulation and insulin resistance under high-fat diet feeding. We further found that SET domain bifurcated 1 (Setdb1) was a SUMOylated protein and that SUMOylation promoted Setdb1 occupancy on the promoter locus of Pparg and Cebpa genes to suppress their expressions by H3K9me3. Senp2 could suppress Setdb1 function by de-SUMOylation. In adipocyte Senp2-deficiency mice, accumulation of the SUMOylated Setdb1 suppressed the expression of Pparg and Cebpa genes as well as lipid metabolism-related target genes, which would decrease the ability of lipid storage in adipocytes. These results revealed the crucial role of Senp2-Setdb1 axis in controlling adipose lipid storage.

The role of SUMOylation in ageing and senescent decline.

PubMed

Princz, Andrea; Tavernarakis, Nektarios

2017-03-01

Posttranslational protein modifications are playing crucial roles in essential cellular mechanisms. SUMOylation is a reversible posttranslational modification of specific target proteins by the attachment of a small ubiquitin-like protein. Although the mechanism of conjugation of SUMO to proteins is analogous to ubiquitination, it requires its own, specific set of enzymes. The consequences of SUMOylation are widely variable, depending on the physiological state of the cell and the attached SUMO isoform. Accumulating recent findings have revealed a prominent role of SUMOylation in molecular pathways that govern senescence and ageing. Here, we review the link between SUMO attachment events and cellular processes that influence senescence and ageing, including promyelocytic leukaemia (PML) nuclear body and telomere function, autophagy, reactive oxygen species (ROS) homeostasis and growth factor signalling. Copyright © 2017 Elsevier B.V. All rights reserved.

Phosphorylated and sumoylation-deficient progesterone receptors drive proliferative gene signatures during breast cancer progression.

PubMed

Knutson, Todd P; Daniel, Andrea R; Fan, Danhua; Silverstein, Kevin At; Covington, Kyle R; Fuqua, Suzanne Aw; Lange, Carol A

2012-06-14

Progesterone receptors (PR) are emerging as important breast cancer drivers. Phosphorylation events common to breast cancer cells impact PR transcriptional activity, in part by direct phosphorylation. PR-B but not PR-A isoforms are phosphorylated on Ser294 by mitogen activated protein kinase (MAPK) and cyclin dependent kinase 2 (CDK2). Phospho-Ser294 PRs are resistant to ligand-dependent Lys388 SUMOylation (that is, a repressive modification). Antagonism of PR small ubiquitin-like modifier (SUMO)ylation by mitogenic protein kinases suggests a mechanism for derepression (that is, transcriptional activation) of target genes. As a broad range of PR protein expression is observed clinically, a PR gene signature would provide a valuable marker of PR contribution to early breast cancer progression. Global gene expression patterns were measured in T47D and MCF-7 breast cancer cells expressing either wild-type (SUMOylation-capable) or K388R (SUMOylation-deficient) PRs and subjected to pathway analysis. Gene sets were validated by RT-qPCR. Recruitment of coregulators and histone methylation levels were determined by chromatin immunoprecipitation. Changes in cell proliferation and survival were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and western blotting. Finally, human breast tumor cohort datasets were probed to identify PR-associated gene signatures; metagene analysis was employed to define survival rates in patients whose tumors express a PR gene signature. 'SUMO-sensitive' PR target genes primarily include genes required for proliferative and pro-survival signaling. DeSUMOylated K388R receptors are preferentially recruited to enhancer regions of derepressed genes (that is, MSX2, RGS2, MAP1A, and PDK4) with the steroid receptor coactivator, CREB-(cAMP-response element-binding protein)-binding protein (CBP), and mixed lineage leukemia 2 (MLL2), a histone methyltransferase mediator of nucleosome remodeling. PR SUMOylation blocks these events, suggesting that SUMO modification of PR prevents interactions with mediators of early chromatin remodeling at 'closed' enhancer regions. SUMO-deficient (phospho-Ser294) PR gene signatures are significantly associated with human epidermal growth factor 2 (ERBB2)-positive luminal breast tumors and predictive of early metastasis and shortened survival. Treatment with antiprogestin or MEK inhibitor abrogated expression of SUMO-sensitive PR target-genes and inhibited proliferation in BT-474 (estrogen receptor (ER)+/PR+/ERBB2+) breast cancer cells. We conclude that reversible PR SUMOylation/deSUMOylation profoundly alters target gene selection in breast cancer cells. Phosphorylation-induced PR deSUMOylation favors a permissive chromatin environment via recruitment of CBP and MLL2. Patients whose ER+/PR+ tumors are driven by hyperactive (that is, derepressed) phospho-PRs may benefit from endocrine (antiestrogen) therapies that contain an antiprogestin.

The Defective Nuclear Lamina in Hutchinson-Gilford Progeria Syndrome Disrupts the Nucleocytoplasmic Ran Gradient and Inhibits Nuclear Localization of Ubc9▿

PubMed Central

Kelley, Joshua B.; Datta, Sutirtha; Snow, Chelsi J.; Chatterjee, Mandovi; Ni, Li; Spencer, Adam; Yang, Chun-Song; Cubeñas-Potts, Caelin; Matunis, Michael J.; Paschal, Bryce M.

2011-01-01

The mutant form of lamin A responsible for the premature aging disease Hutchinson-Gilford progeria syndrome (termed progerin) acts as a dominant negative protein that changes the structure of the nuclear lamina. How the perturbation of the nuclear lamina in progeria is transduced into cellular changes is undefined. Using patient fibroblasts and a variety of cell-based assays, we determined that progerin expression in Hutchinson-Gilford progeria syndrome inhibits the nucleocytoplasmic transport of several factors with key roles in nuclear function. We found that progerin reduces the nuclear/cytoplasmic concentration of the Ran GTPase and inhibits the nuclear localization of Ubc9, the sole E2 for SUMOylation, and of TPR, the nucleoporin that forms the basket on the nuclear side of the nuclear pore complex. Forcing the nuclear localization of Ubc9 in progerin-expressing cells rescues the Ran gradient and TPR import, indicating that these pathways are linked. Reducing nuclear SUMOylation decreases the nuclear mobility of the Ran nucleotide exchange factor RCC1 in vivo, and the addition of SUMO E1 and E2 promotes the dissociation of RCC1 and Ran from chromatin in vitro. Our data suggest that the cellular effects of progerin are transduced, at least in part, through reduced function of the Ran GTPase and SUMOylation pathways. PMID:21670151

The defective nuclear lamina in Hutchinson-gilford progeria syndrome disrupts the nucleocytoplasmic Ran gradient and inhibits nuclear localization of Ubc9.

PubMed

Kelley, Joshua B; Datta, Sutirtha; Snow, Chelsi J; Chatterjee, Mandovi; Ni, Li; Spencer, Adam; Yang, Chun-Song; Cubeñas-Potts, Caelin; Matunis, Michael J; Paschal, Bryce M

2011-08-01

The mutant form of lamin A responsible for the premature aging disease Hutchinson-Gilford progeria syndrome (termed progerin) acts as a dominant negative protein that changes the structure of the nuclear lamina. How the perturbation of the nuclear lamina in progeria is transduced into cellular changes is undefined. Using patient fibroblasts and a variety of cell-based assays, we determined that progerin expression in Hutchinson-Gilford progeria syndrome inhibits the nucleocytoplasmic transport of several factors with key roles in nuclear function. We found that progerin reduces the nuclear/cytoplasmic concentration of the Ran GTPase and inhibits the nuclear localization of Ubc9, the sole E2 for SUMOylation, and of TPR, the nucleoporin that forms the basket on the nuclear side of the nuclear pore complex. Forcing the nuclear localization of Ubc9 in progerin-expressing cells rescues the Ran gradient and TPR import, indicating that these pathways are linked. Reducing nuclear SUMOylation decreases the nuclear mobility of the Ran nucleotide exchange factor RCC1 in vivo, and the addition of SUMO E1 and E2 promotes the dissociation of RCC1 and Ran from chromatin in vitro. Our data suggest that the cellular effects of progerin are transduced, at least in part, through reduced function of the Ran GTPase and SUMOylation pathways.

Solubility shift and SUMOylaltion of promyelocytic leukemia (PML) protein in response to arsenic(III) and fate of the SUMOylated PML

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirano, Seishiro, E-mail: seishiro@nies.go.jp; Graduate School of Pharmaceutical Sciences, Chiba University; Tadano, Mihoko

2015-09-15

Promyelocytic leukemia (PML), which is a tumor suppressor protein that nevertheless plays an important role in the maintenance of leukemia initiating cells, is known to be biochemically modified by As{sup 3+}. We recently developed a simple method to evaluate the modification of PML by As{sup 3+} resulting in a change in solubility and the covalent binding of small ubiquitin-like modifier (SUMO). Here we semi-quantitatively investigated the SUMOylation of PML using HEK293 cells which were stably transfected with PML-VI (HEK-PML). Western blot analyses indicated that PML became insoluble in cold RadioImmunoPrecipitation Assay (RIPA) lysis buffer and was SUMOylated by both SUMO2/3more » and SUMO1 by As{sup 3+}. Surprisingly SUMO1 monomers were completely utilized for the SUMOylation of PML. Antimony (Sb{sup 3+}) but not bismuth (Bi{sup 3+}), Cu{sup 2+}, or Cd{sup 2+} biochemically modified PML similarly. SUMOylated PML decreased after removal of As{sup 3+} from the culture medium. However, unSUMOylated PML was still recovered in the RIPA-insoluble fraction, suggesting that SUMOylation is not requisite for changing the RIPA-soluble PML into the RIPA-insoluble form. Immunofluorescence staining of As{sup 3+}-exposed cells indicated that SUMO2/3 was co-localized with PML in the nuclear bodies. However, some PML protein was present in peri-nuclear regions without SUMO2/3. Functional Really Interesting New Gene (RING)-deleted mutant PML neither formed PML nuclear bodies nor was biochemically modified by As{sup 3+}. Conjugation with intracellular glutathione may explain the accessibility of As{sup 3+} and Sb{sup 3+} to PML in the nuclear region evading chelation and entrapping by cytoplasmic proteins such as metallothioneins. - Highlights: • As{sup 3+} is a carcinogen and also a therapeutic agent for leukemia. • PML becomes insoluble in RIPA and SUMOylated by As{sup 3+}. • Sb{sup 3+} modifies PML similar to As{sup 3+}. • Functional RING motif is necessary for As{sup 3+}-induced PML modification.« less

Sumoylation of CCAAT/enhancer-binding protein α is implicated in hematopoietic stem/progenitor cell development through regulating runx1 in zebrafish.

PubMed

Yuan, Hao; Zhang, Tao; Liu, Xiaohui; Deng, Min; Zhang, Wenqing; Wen, Zilong; Chen, Saijuan; Chen, Zhu; de The, Hugues; Zhou, Jun; Zhu, Jun

2015-03-11

The small ubiquitin-related modifier (SUMO) participates in various cellular processes, including maintenance of genome integrity, nuclear transport, transcription and signal transduction. However, the biological function of sumoylation in hematopoiesis has not been fully explored. We show here that definitive hematopoietic stem/progenitor cells (HSPCs) are depleted in SUMO-deficient zebrafish embryos. Impairment of sumoylation attenuates HSPC generation and proliferation. The hyposumoylation triggered HSPC defects are CCAAT/enhancer-binding protein α (C/ebpα) dependent. Critically, a SUMO-C/ebpα fusion rescues the defective hematopoiesis in SUMO-deficient embryos, at least in part through restored runx1 expression. While C/ebpα-dependent transcription is involved in myeloid differentiation, our studies here reveal that C/ebpα sumoylation is essential for HSPC development during definitive hematopoiesis.

Sumoylation of CCAAT/enhancer-binding protein α is implicated in hematopoietic stem/progenitor cell development through regulating runx1 in zebrafish

PubMed Central

Yuan, Hao; Zhang, Tao; Liu, Xiaohui; Deng, Min; Zhang, Wenqing; Wen, Zilong; Chen, Saijuan; Chen, Zhu; de The, Hugues; Zhou, Jun; Zhu, Jun

2015-01-01

The small ubiquitin-related modifier (SUMO) participates in various cellular processes, including maintenance of genome integrity, nuclear transport, transcription and signal transduction. However, the biological function of sumoylation in hematopoiesis has not been fully explored. We show here that definitive hematopoietic stem/progenitor cells (HSPCs) are depleted in SUMO-deficient zebrafish embryos. Impairment of sumoylation attenuates HSPC generation and proliferation. The hyposumoylation triggered HSPC defects are CCAAT/enhancer-binding protein α (C/ebpα) dependent. Critically, a SUMO-C/ebpα fusion rescues the defective hematopoiesis in SUMO-deficient embryos, at least in part through restored runx1 expression. While C/ebpα-dependent transcription is involved in myeloid differentiation, our studies here reveal that C/ebpα sumoylation is essential for HSPC development during definitive hematopoiesis. PMID:25757417

Inhibition of DNA binding of Sox2 by the SUMO conjugation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsuruzoe, Shu; Ishihara, Ko; Uchimura, Yasuhiro

2006-12-29

Sox2 is a member of the high mobility group (HMG) domain DNA-binding proteins for transcriptional control and chromatin architecture. The HMG domain of Sox2 binds the DNA to facilitate transactivation by the cooperative transcription factors such as Oct3/4. We report that mouse Sox2 is modified by SUMO at lysine 247. Substitution of the target lysine to arginine lost the sumoylation but little affected transcriptional potential or nuclear localization of Sox2. By contrast with the unmodified form, Sox2 fused to SUMO-1 did not augment transcription via the Fgf4 enhancer in the presence of Oct3/4. Further, SUMO-1-conjugated Sox2 at the lysine 247more » or at the carboxyl terminus reduced the binding to the Fgf4 enhancer. These indicate that Sox2 sumoylation negatively regulates its transcriptional role through impairing the DNA binding.« less

Expression, Localization of SUMO-1, and Analyses of Potential SUMOylated Proteins in Bubalus bubalis Spermatozoa

PubMed Central

Brohi, Rahim Dad; Wang, Li; Hassine, Najla Ben; Cao, Jing; Talpur, Hira Sajjad; Wu, Di; Huang, Chun-Jie; Rehman, Zia-Ur; Bhattarai, Dinesh; Huo, Li-Jun

2017-01-01

Mature spermatozoa have highly condensed DNA that is essentially silent both transcriptionally and translationally. Therefore, post translational modifications are very important for regulating sperm motility, morphology, and for male fertility in general. Protein sumoylation was recently demonstrated in human and rodent spermatozoa, with potential consequences for sperm motility and DNA integrity. We examined the expression and localization of small ubiquitin-related modifier-1 (SUMO-1) in the sperm of water buffalo (Bubalus bubalis) using immunofluorescence analysis. We confirmed the expression of SUMO-1 in the acrosome. We further found that SUMO-1 was lost if the acrosome reaction was induced by calcium ionophore A23187. Proteins modified or conjugated by SUMO-1 in water buffalo sperm were pulled down and analyzed by mass spectrometry. Sixty proteins were identified, including proteins important for sperm morphology and motility, such as relaxin receptors and cytoskeletal proteins, including tubulin chains, actins, and dyneins. Forty-six proteins were predicted as potential sumoylation targets. The expression of SUMO-1 in the acrosome region of water buffalo sperm and the identification of potentially SUMOylated proteins important for sperm function implicates sumoylation as a crucial PTM related to sperm function. PMID:28659810

SUMOylation of the KRAB zinc-finger transcription factor PARIS/ZNF746 regulates its transcriptional activity.

PubMed

Nishida, Tamotsu; Yamada, Yoshiji

2016-05-13

Parkin-interacting substrate (PARIS), a member of the family of Krüppel-associated box (KRAB)-containing zinc-finger transcription factors, is a substrate of the ubiquitin E3 ligase parkin. PARIS represses the expression of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), although the underlying mechanisms remain largely unknown. In the present study, we demonstrate that PARIS can be SUMOylated, and its SUMOylation plays a role in the repression of PGC-1a promoter activity. Protein inhibitor of activated STAT y (PIASy) was identified as an interacting protein of PARIS and shown to enhance its SUMOylation. PIASy repressed PGC-1a promoter activity, and this effect was attenuated by PARIS in a manner dependent on its SUMOylation status. Co-expression of SUMO-1 with PIASy completely repressed PGC-1a promoter activity independently of PARIS expression. PARIS-mediated PGC-1a promoter repression depended on the activity of histone deacetylases (HDAC), whereas PIASy repressed the PGC-1a promoter in an HDAC-independent manner. Taken together, these results suggest that PARIS and PIASy modulate PGC-1a gene transcription through distinct molecular mechanisms. Copyright © 2016 Elsevier Inc. All rights reserved.

SUMOylated MAFB promotes colorectal cancer tumorigenesis

PubMed Central

Xie, Yin-Yin; Sun, Xiao-Jian; Zhao, Ren; Huang, Qiu-Hua

2016-01-01

The transcription factor, v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB), promotes tumorigenesis in some cancers. In this study, we found that MAFB levels were increased in clinical colorectal cancer (CRC) samples, and higher expression correlated with more advanced TNM stage. We identified MAFB amplifications in a majority of tumor types in an assessment of The Cancer Genome Atlas database. Altered MAFB levels due to gene amplification, deletion, mutation, or transcription upregulation occurred in 9% of CRC cases within the database. shRNA knockdown experiments demonstrated that MAFB deficiency blocked CRC cell proliferation by arresting the cell cycle at G0/G1 phase in vitro. We found that MAFB could be SUMOylated by SUMO1 at lysine 32, and this modification was critical for cell cycle regulation by MAFB in CRC cells. SUMOylated MAFB directly regulated cyclin-dependent kinase 6 transcription by binding to its promoter. MAFB knockdown CRC cell xenograft tumors in mice grew more slowly than controls, and wild-type MAFB-overexpressing tumors grew more quickly than tumors overexpressing MAFB mutated at lysine 32. These data suggest that SUMOylated MAFB promotes CRC tumorigenesis through cell cycle regulation. MAFB and its SUMOylation process may serve as novel therapeutic targets for CRC treatment. PMID:27829226

SUMOylation regulates TGF-β1/Smad4 signalling in-resistant glioma cells.

PubMed

Wang, Zhengfeng; Wang, Kai; Wang, Ruihua; Liu, Xianzhi

2017-12-18

The aim of this study was to explore the role of TGF-β1/Smad4 signalling in the DNA damage-induced ionization radiation (IR) resistance of glioma cells. T98G cells were assigned to the IR group (treated with IR) or the Blank group (with no treatment). The IR-treated cells were also treated/transfected with the TGF-β receptor inhibitor SB431542, SUMO1-overexpressing plasmids (SUMO1 group), SUMO1-interfering plasmids (si-SUMO1 group) or negative control plasmids group. The wound-healing capacity, cell proliferation and cell apoptosis were evaluated by the scratch assay, flow cytometry and the CCK-8 assay, respectively, and protein interactions were investigated by coimmunoprecipitation and colocalization assays. IR-treated T98G cells had DNA damage, but the wound-healing capacity and cell apoptosis were not significantly suppressed. DNA damage also induced TGF-β1, Smad4, SUMO1, SUMO2/3 and Ubc9 expression. In IR-treated cells cultured with SB431542, the wound-healing capacity and proliferation were promoted. SUMO1 and Smad4 colocalized in the nucleus of T98G cells, and the IR-treated cells had a significantly higher expression of the SUMO1-Smad4 protein complex. Smad4 expression in the nucleus was significantly reduced in the si-SUMO1 group, but was markedly increased in the SUMO1 group; the SUMO1 group had significantly elevated apoptotic activity, whereas the si-SUMO1 group showed significantly suppressed apoptotic activity and the si-SUMO1+SB41542 group had the lowest levels of cell apoptosis. DNA damage may activate Smad4 SUMOylation and the SUMOylation of Smad4 participates in the activation of TGF-β/Smad4 signalling; therefore, enhanced Smad4 SUMOylation is critical for the damage-induced activation of IR resistance.

System-wide Analysis of SUMOylation Dynamics in Response to Replication Stress Reveals Novel Small Ubiquitin-like Modified Target Proteins and Acceptor Lysines Relevant for Genome Stability*

PubMed Central

Xiao, Zhenyu; Chang, Jer-Gung; Hendriks, Ivo A.; Sigurðsson, Jón Otti; Olsen, Jesper V.; Vertegaal, Alfred C.O.

2015-01-01

Genotoxic agents can cause replication fork stalling in dividing cells because of DNA lesions, eventually leading to replication fork collapse when the damage is not repaired. Small Ubiquitin-like Modifiers (SUMOs) are known to counteract replication stress, nevertheless, only a small number of relevant SUMO target proteins are known. To address this, we have purified and identified SUMO-2 target proteins regulated by replication stress in human cells. The developed methodology enabled single step purification of His10-SUMO-2 conjugates under denaturing conditions with high yield and high purity. Following statistical analysis on five biological replicates, a total of 566 SUMO-2 targets were identified. After 2 h of hydroxyurea treatment, 10 proteins were up-regulated for SUMOylation and two proteins were down-regulated for SUMOylation, whereas after 24 h, 35 proteins were up-regulated for SUMOylation, and 13 proteins were down-regulated for SUMOylation. A site-specific approach was used to map over 1000 SUMO-2 acceptor lysines in target proteins. The methodology is generic and is widely applicable in the ubiquitin field. A large subset of these identified proteins function in one network that consists of interacting replication factors, transcriptional regulators, DNA damage response factors including MDC1, ATR-interacting protein ATRIP, the Bloom syndrome protein and the BLM-binding partner RMI1, the crossover junction endonuclease EME1, BRCA1, and CHAF1A. Furthermore, centromeric proteins and signal transducers were dynamically regulated by SUMOylation upon replication stress. Our results uncover a comprehensive network of SUMO target proteins dealing with replication damage and provide a framework for detailed understanding of the role of SUMOylation to counteract replication stress. Ultimately, our study reveals how a post-translational modification is able to orchestrate a large variety of different proteins to integrate different nuclear processes with the aim of dealing with the induced DNA damage. PMID:25755297

The Spindle Positioning Protein Kar9p Interacts With the Sumoylation Machinery in Saccharomyces cerevisiae

PubMed Central

Meednu, Nida; Hoops, Harold; D'Silva, Sonia; Pogorzala, Leah; Wood, Schuyler; Farkas, David; Sorrentino, Mark; Sia, Elaine; Meluh, Pam; Miller, Rita K.

2008-01-01

Accurate positioning of the mitotic spindle is important for the genetic material to be distributed evenly in dividing cells, but little is known about the mechanisms that regulate this process. Here we report that two microtubule-associated proteins important for spindle positioning interact with several proteins in the sumoylation pathway. By two-hybrid analysis, Kar9p and Bim1p interact with the yeast SUMO Smt3p, the E2 enzyme Ubc9p, an E3 Nfi1p, as well as Wss1p, a weak suppressor of a temperature-sensitive smt3 allele. The physical interaction between Kar9p and Ubc9p was confirmed by in vitro binding assays. A single-amino-acid substitution in Kar9p, L304P disrupted its two-hybrid interaction with proteins in the sumoylation pathway, but retained its interactions with the spindle positioning proteins Bim1p, Stu2p, Bik1p, and Myo2p. The kar9-L304P mutant showed defects in positioning the mitotic spindle, with the spindle located more distally than normal. Whereas wild-type Kar9p-3GFP normally localizes to only the bud-directed spindle pole body (SPB), Kar9p-L304P-3GFP was mislocalized to both SPBs. Using a reconstitution assay, Kar9p was sumoylated in vitro. We propose a model in which sumoylation regulates spindle positioning by restricting Kar9p to one SPB. These findings raise the possibility that sumoylation could regulate other microtubule-dependent processes. PMID:18832349

DeSUMOylation of MKK7 kinase by the SUMO2/3 protease SENP3 potentiates lipopolysaccharide-induced inflammatory signaling in macrophages

PubMed Central

Lao, Yimin; Yang, Kai; Wang, Zhaojun; Sun, Xueqing; Zou, Qiang; Yu, Xiaoyan; Cheng, Jinke; Tong, Xuemei; Yeh, Edward T. H.; Yang, Jie; Yi, Jing

2018-01-01

Protein SUMOylation has been reported to play a role in innate immune response, but the enzymes, substrates, and consequences of the specific inflammatory signaling events are largely unknown. Reactive oxygen species (ROS) are abundantly produced during macrophage activation and required for Toll-like receptor 4 (TLR4)–mediated inflammatory signaling. Previously, we demonstrated that SENP3 is a redox-sensitive SUMO2/3 protease. To explore any links between reversible SUMOylation and ROS-related inflammatory signaling in macrophage activation, we generated mice with Senp3 conditional knock-out in myeloid cells. In bacterial lipopolysaccharide (LPS)-induced in vitro and in vivo inflammation models, we found that SENP3 deficiency markedly compromises the activation of TLR4 inflammatory signaling and the production of proinflammatory cytokines in macrophages exposed to LPS. Moreover, Senp3 conditional knock-out mice were significantly less susceptible to septic shock. Of note, SENP3 deficiency was associated with impairment in JNK phosphorylation. We found that MKK7, which selectively phosphorylates JNK, is a SENP3 substrate and that SENP3-mediated deSUMOylation of MKK7 may favor its binding to JNK. Importantly, ROS-dependent SENP3 accumulation and MKK7 deSUMOylation rapidly occurred after LPS stimulation. In conclusion, our findings indicate that SENP3 potentiates LPS-induced TLR4 signaling via deSUMOylation of MKK7 leading to enhancement in JNK phosphorylation and the downstream events. Therefore this work provides novel mechanistic insights into redox regulation of innate immune responses. PMID:29352108

Identification of a molecular recognition feature in the E1A oncoprotein that binds the SUMO conjugase UBC9 and likely interferes with polySUMOylation.

PubMed

Yousef, A F; Fonseca, G J; Pelka, P; Ablack, J N G; Walsh, C; Dick, F A; Bazett-Jones, D P; Shaw, G S; Mymryk, J S

2010-08-19

Hub proteins have central roles in regulating cellular processes. By targeting a single cellular hub, a viral oncogene may gain control over an entire module in the cellular interaction network that is potentially comprised of hundreds of proteins. The adenovirus E1A oncoprotein is a viral hub that interacts with many cellular hub proteins by short linear motifs/molecular recognition features (MoRFs). These interactions transform the architecture of the cellular protein interaction network and virtually reprogram the cell. To identify additional MoRFs within E1A, we screened portions of E1A for their ability to activate yeast pseudohyphal growth or differentiation. This identified a novel functional region within E1A conserved region 2 comprised of the sequence EVIDLT. This MoRF is necessary and sufficient to bind the N-terminal region of the SUMO conjugase UBC9, which also interacts with SUMO noncovalently and is involved in polySUMOylation. Our results suggest that E1A interferes with polySUMOylation, but not with monoSUMOylation. These data provide the first insight into the consequences of the interaction of E1A with UBC9, which was initially described in 1996. We further demonstrate that polySUMOylation regulates pseudohyphal growth and promyelocytic leukemia body reorganization by E1A. In conclusion, the interaction of the E1A oncogene with UBC9 mimics the normal binding between SUMO and UBC9 and represents a novel mechanism to modulate polySUMOylation.

JASSA: a comprehensive tool for prediction of SUMOylation sites and SIMs.

PubMed

Beauclair, Guillaume; Bridier-Nahmias, Antoine; Zagury, Jean-François; Saïb, Ali; Zamborlini, Alessia

2015-11-01

Post-translational modification by the Small Ubiquitin-like Modifier (SUMO) proteins, a process termed SUMOylation, is involved in many fundamental cellular processes. SUMO proteins are conjugated to a protein substrate, creating an interface for the recruitment of cofactors harboring SUMO-interacting motifs (SIMs). Mapping both SUMO-conjugation sites and SIMs is required to study the functional consequence of SUMOylation. To define the best candidate sites for experimental validation we designed JASSA, a Joint Analyzer of SUMOylation site and SIMs. JASSA is a predictor that uses a scoring system based on a Position Frequency Matrix derived from the alignment of experimental SUMOylation sites or SIMs. Compared with existing web-tools, JASSA displays on par or better performances. Novel features were implemented towards a better evaluation of the prediction, including identification of database hits matching the query sequence and representation of candidate sites within the secondary structural elements and/or the 3D fold of the protein of interest, retrievable from deposited PDB files. JASSA is freely accessible at http://www.jassa.fr/. Website is implemented in PHP and MySQL, with all major browsers supported. guillaume.beauclair@inserm.fr Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Viral Mimicry to Usurp Ubiquitin and SUMO Host Pathways

PubMed Central

Wimmer, Peter; Schreiner, Sabrina

2015-01-01

Posttranslational modifications (PTMs) of proteins include enzymatic changes by covalent addition of cellular regulatory determinants such as ubiquitin (Ub) and small ubiquitin-like modifier (SUMO) moieties. These modifications are widely used by eukaryotic cells to control the functional repertoire of proteins. Over the last decade, it became apparent that the repertoire of ubiquitiylation and SUMOylation regulating various biological functions is not restricted to eukaryotic cells, but is also a feature of human virus families, used to extensively exploit complex host-cell networks and homeostasis. Intriguingly, besides binding to host SUMO/Ub control proteins and interfering with the respective enzymatic cascade, many viral proteins mimic key regulatory factors to usurp this host machinery and promote efficient viral outcomes. Advanced detection methods and functional studies of ubiquitiylation and SUMOylation during virus-host interplay have revealed that human viruses have evolved a large arsenal of strategies to exploit these specific PTM processes. In this review, we highlight the known viral analogs orchestrating ubiquitin and SUMO conjugation events to subvert and utilize basic enzymatic pathways. PMID:26343706

SUMOylation of the mitochondrial fission protein Drp1 occurs at multiple nonconsensus sites within the B domain and is linked to its activity cycle

PubMed Central

Figueroa-Romero, Claudia; Iñiguez-Lluhí, Jorge A.; Stadler, Julia; Chang, Chuang-Rung; Arnoult, Damien; Keller, Peter J.; Hong, Yu; Blackstone, Craig; Feldman, Eva L.

2009-01-01

Dynamin-related protein (Drp) 1 is a key regulator of mitochondrial fission and is composed of GTP-binding, Middle, insert B, and C-terminal GTPase effector (GED) domains. Drp1 associates with mitochondrial fission sites and promotes membrane constriction through its intrinsic GTPase activity. The mechanisms that regulate Drp1 activity remain poorly understood but are likely to involve reversible post-translational modifications, such as conjugation of small ubiquitin-like modifier (SUMO) proteins. Through a detailed analysis, we find that Drp1 interacts with the SUMO-conjugating enzyme Ubc9 via multiple regions and demonstrate that Drp1 is a direct target of SUMO modification by all three SUMO isoforms. While Drp1 does not harbor consensus SUMOylation sequences, our analysis identified2 clusters of lysine residues within the B domain that serve as noncanonical conjugation sites. Although initial analysis indicates that mitochondrial recruitment of ectopically expressed Drp1 in response to staurosporine is unaffected by loss of SUMOylation, we find that Drp1 SUMOylation is enhanced in the context of the K38A mutation. This dominant-negative mutant, which is deficient in GTP binding and hydrolysis, does not associate with mitochondria and prevents normal mitochondrial fission. This finding suggests that SUMOylation of Drp1 is linked to its activity cycle and is influenced by Drp1 localization.—Figueroa-Romero, C., Iñiguez-Lluhí, J. A., Stadler, J., Chang, C.-R., Arnoult, D., Keller, P. J., Hong, Y., Blackstone, C., Feldman, E. L. SUMOylation of the mitochondrial fission protein Drp1 occurs at multiple nonconsensus sites within the B domain and is linked to its activity cycle. PMID:19638400

Systematic Localization and Identification of SUMOylation Substrates in Knock-In Mice Expressing Affinity-Tagged SUMO1.

PubMed

Tirard, Marilyn; Brose, Nils

2016-01-01

Protein SUMOylation is a posttranslational protein modification that is emerging as a key regulatory process in neurobiology. To date, however, SUMOylation in vivo has only been studied cursorily. Knock-in mice expressing His6-HA-SUMO1 from the Sumo1 locus allow for the highly specific localization and identification of endogenous SUMO1 substrates under physiological and pathophysiological conditions. By making use of the HA-tag and using wild-type mice for highly stringent negative control samples, SUMO1 targets can be specifically localized in and purified from cultured mouse nerve cells and mouse tissues.

Managing the complexity of communication: regulation of gap junctions by post-translational modification

PubMed Central

Axelsen, Lene N.; Calloe, Kirstine; Holstein-Rathlou, Niels-Henrik; Nielsen, Morten S.

2013-01-01

Gap junctions are comprised of connexins that form cell-to-cell channels which couple neighboring cells to accommodate the exchange of information. The need for communication does, however, change over time and therefore must be tightly controlled. Although the regulation of connexin protein expression by transcription and translation is of great importance, the trafficking, channel activity and degradation are also under tight control. The function of connexins can be regulated by several post translational modifications, which affect numerous parameters; including number of channels, open probability, single channel conductance or selectivity. The most extensively investigated post translational modifications are phosphorylations, which have been documented in all mammalian connexins. Besides phosphorylations, some connexins are known to be ubiquitinated, SUMOylated, nitrosylated, hydroxylated, acetylated, methylated, and γ-carboxyglutamated. The aim of the present review is to summarize our current knowledge of post translational regulation of the connexin family of proteins. PMID:24155720

Inhibition of HSF2 SUMOylation via MEL18 upregulates IGF-IIR and leads to hypertension-induced cardiac hypertrophy.

PubMed

Huang, Chih-Yang; Kuo, Chia-Hua; Pai, Pei-Ying; Ho, Tsung-Jung; Lin, Yueh-Min; Chen, Ray-Jade; Tsai, Fuu-Jen; Vijaya Padma, V; Kuo, Wei-Wen; Huang, Chih-Yang

2018-04-15

Cardiac hypertrophy is a major characteristic of early-stage hypertension-related heart failure. We have found that the insulin-like growth factor receptor II (IGF-IIR) signaling was critical for hypertensive angiotensin II-induced cardiomyocyte hypertrophy and apoptosis. Moreover, this IGF-IIR signaling was elegantly modulated by the heat shock transcription factors (HSFs) during heart failure. However, the detailed mechanism by which HSFs regulates IGF-IIR during hypertension-induced cardiac hypertrophy remains elusive. In this study, we found that heat shock transcription factor 2 (HSF2) activated IGF-IIR to induce cardiac hypertrophy for hypertension-induced heart failure. The transcriptional activity of HSF2 appeared to be primarily mediated by SUMOylation via conjugation with small ubiquitin-like modifier-1 (SUMO-1). The SUMOylation of HSF2 was severely attenuated by MEL18 (also known as polycomb group ring finger 2 or PCGF2) in the heart of spontaneously hypertensive rats (SHR). Inhibition of HSF2 SUMOylation severely induced cardiac hypertrophy via IGF-IIR-mediated signaling in hypertensive rats. Angiotensin II receptor type I blocker (ARB) treatment in spontaneously hypertensive rats restored HSF2 SUMOylation and alleviated the cardiac defects. Thus, our study uncovered a novel MEL18-SUMO-1-HSF2-IGF-IIR pathway in the heart that profoundly influences cardiac hypertrophy for hypertension-induced heart failure. Copyright © 2017 Elsevier B.V. All rights reserved.

SUMO-Modification of the La Protein Facilitates Binding to mRNA In Vitro and in Cells.

PubMed

Kota, Venkatesh; Sommer, Gunhild; Durette, Chantal; Thibault, Pierre; van Niekerk, Erna A; Twiss, Jeffery L; Heise, Tilman

2016-01-01

The RNA-binding protein La is involved in several aspects of RNA metabolism including the translational regulation of mRNAs and processing of pre-tRNAs. Besides its well-described phosphorylation by Casein kinase 2, the La protein is also posttranslationally modified by the Small Ubiquitin-like MOdifier (SUMO), but the functional outcome of this modification has not been defined. The objective of this study was to test whether sumoylation changes the RNA-binding activity of La. Therefore, we established an in vitro sumoylation assay for recombinant human La and analyzed its RNA-binding activity by electrophoretic mobility shift assays. We identified two novel SUMO-acceptor sites within the La protein located between the RNA recognition motif 1 and 2 and we demonstrate for the first time that sumoylation facilitates the RNA-binding of La to small RNA oligonucleotides representing the oligopyrimidine tract (TOP) elements from the 5' untranslated regions (UTR) of mRNAs encoding ribosomal protein L22 and L37 and to a longer RNA element from the 5' UTR of cyclin D1 (CCND1) mRNA in vitro. Furthermore, we show by RNA immunoprecipitation experiments that a La mutant deficient in sumoylation has impaired RNA-binding activity in cells. These data suggest that modulating the RNA-binding activity of La by sumoylation has important consequences on its functionality.

SUMO-Modification of the La Protein Facilitates Binding to mRNA In Vitro and in Cells

PubMed Central

Kota, Venkatesh; Sommer, Gunhild; Durette, Chantal; Thibault, Pierre; van Niekerk, Erna A.; Twiss, Jeffery L.

2016-01-01

The RNA-binding protein La is involved in several aspects of RNA metabolism including the translational regulation of mRNAs and processing of pre-tRNAs. Besides its well-described phosphorylation by Casein kinase 2, the La protein is also posttranslationally modified by the Small Ubiquitin-like MOdifier (SUMO), but the functional outcome of this modification has not been defined. The objective of this study was to test whether sumoylation changes the RNA-binding activity of La. Therefore, we established an in vitro sumoylation assay for recombinant human La and analyzed its RNA-binding activity by electrophoretic mobility shift assays. We identified two novel SUMO-acceptor sites within the La protein located between the RNA recognition motif 1 and 2 and we demonstrate for the first time that sumoylation facilitates the RNA-binding of La to small RNA oligonucleotides representing the oligopyrimidine tract (TOP) elements from the 5’ untranslated regions (UTR) of mRNAs encoding ribosomal protein L22 and L37 and to a longer RNA element from the 5’ UTR of cyclin D1 (CCND1) mRNA in vitro. Furthermore, we show by RNA immunoprecipitation experiments that a La mutant deficient in sumoylation has impaired RNA-binding activity in cells. These data suggest that modulating the RNA-binding activity of La by sumoylation has important consequences on its functionality. PMID:27224031

Defining the SUMO System in Maize: SUMOylation Is Up-Regulated during Endosperm Development and Rapidly Induced by Stress1[OPEN

PubMed Central

Augustine, Robert C.; Rytz, Thérèse C.

2016-01-01

In response to abiotic and biotic challenges, plants rapidly attach small ubiquitin-related modifier (SUMO) to a large collection of nuclear proteins, with studies in Arabidopsis (Arabidopsis thaliana) linking SUMOylation to stress tolerance via its modification of factors involved in chromatin and RNA dynamics. Despite this importance, little is known about SUMOylation in crop species. Here, we describe the plant SUMO system at the phylogenetic, biochemical, and transcriptional levels with a focus on maize (Zea mays). In addition to canonical SUMOs, land plants encode a loosely constrained noncanonical isoform and a variant containing a long extension upstream of the signature β-grasp fold, with cereals also expressing a novel diSUMO polypeptide bearing two SUMO β-grasp domains in tandem. Maize and other cereals also synthesize a unique SUMO-conjugating enzyme variant with more restricted expression patterns that is enzymatically active despite a distinct electrostatic surface. Maize SUMOylation primarily impacts nuclear substrates, is strongly induced by high temperatures, and displays a memory that suppresses subsequent conjugation. Both in-depth transcript and conjugate profiles in various maize organs point to tissue/cell-specific functions for SUMOylation, with potentially significant roles during embryo and endosperm maturation. Collectively, these studies define the organization of the maize SUMO system and imply important functions during seed development and stress defense. PMID:27208252

Characterization and expression analysis of genes involved in SUMOylation during embryogenesis in rainbow trout (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

SUMOylation is the post-translational modification of proteins by the addition of the small ubiquitin-like modifier (SUMO), which plays an important role in various cellular processes. It has been reported that SUMO and its related proteins are important in diverse reproductive functions such as ovu...

Endogenous TRIM5α Function Is Regulated by SUMOylation and Nuclear Sequestration for Efficient Innate Sensing in Dendritic Cells

PubMed Central

Portilho, Débora M.; Fernandez, Juliette; Ringeard, Mathieu; Machado, Anthony K.; Boulay, Aude; Mayer, Martha; Müller-Trutwin, Michaela; Beignon, Anne-Sophie; Kirchhoff, Frank; Nisole, Sébastien; Arhel, Nathalie J.

2015-01-01

Summary During retroviral infection, viral capsids are subject to restriction by the cellular factor TRIM5α. Here, we show that dendritic cells (DCs) derived from human and non-human primate species lack efficient TRIM5α-mediated retroviral restriction. In DCs, endogenous TRIM5α accumulates in nuclear bodies (NB) that partly co-localize with Cajal bodies in a SUMOylation-dependent manner. Nuclear sequestration of TRIM5α allowed potent induction of type I interferon (IFN) responses during infection, mediated by sensing of reverse transcribed DNA by cGAS. Overexpression of TRIM5α or treatment with the SUMOylation inhibitor ginkgolic acid (GA) resulted in enforced cytoplasmic TRIM5α expression and restored efficient viral restriction but abrogated type I IFN production following infection. Our results suggest that there is an evolutionary trade-off specific to DCs in which restriction is minimized to maximize sensing. TRIM5α regulation via SUMOylation-dependent nuclear sequestration adds to our understanding of how restriction factors are regulated. PMID:26748714

A SUMO-acetyl switch in PXR biology.

PubMed

Cui, Wenqi; Sun, Mengxi; Zhang, Shupei; Shen, Xunan; Galeva, Nadezhda; Williams, Todd D; Staudinger, Jeff L

2016-09-01

Post-translational modification (PTM) of nuclear receptor superfamily members regulates various aspects of their biology to include sub-cellular localization, the repertoire of protein-binding partners, as well as their stability and mode of degradation. The nuclear receptor pregnane X receptor (PXR, NR1I2) is a master-regulator of the drug-inducible gene expression in liver and intestine. The PXR-mediated gene activation program is primarily recognized to increase drug metabolism, drug transport, and drug efflux pathways in these tissues. The activation of PXR also has important implications in significant human diseases including inflammatory bowel disease and cancer. Our recent investigations reveal that PXR is modified by multiple PTMs to include phosphorylation, SUMOylation, and ubiquitination. Using both primary cultures of hepatocytes and cell-based assays, we show here that PXR is modified through acetylation on lysine residues. Further, we show that increased acetylation of PXR stimulates its increased SUMO-modification to support active transcriptional suppression. Pharmacologic inhibition of lysine de-acetylation using trichostatin A (TSA) alters the sub-cellular localization of PXR in cultured hepatocytes, and also has a profound impact upon PXR transactivation capacity. Both the acetylation and SUMOylation status of the PXR protein is affected by its ability to associate with the lysine de-acetylating enzyme histone de-acetylase (HDAC)3 in a complex with silencing mediator of retinoic acid and thyroid hormone receptor (SMRT). Taken together, our data support a model in which a SUMO-acetyl 'switch' occurs such that acetylation of PXR likely stimulates SUMO-modification of PXR to promote the active repression of PXR-target gene expression. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie. Copyright © 2016 Elsevier B.V. All rights reserved.

SUMOylation of DRIL1 Directs Its Transcriptional Activity Towards Leukocyte Lineage-Specific Genes

PubMed Central

van Lohuizen, Maarten; Peeper, Daniel S.

2009-01-01

DRIL1 is an ARID family transcription factor that can immortalize primary mouse fibroblasts, bypass RASV12-induced cellular senescence and collaborate with RASV12 or MYC in mediating oncogenic transformation. It also activates immunoglobulin heavy chain transcription and engages in heterodimer formation with E2F to stimulate E2F-dependent transcription. Little, however, is known about the regulation of DRIL1 activity. Recently, DRIL1 was found to interact with the SUMO-conjugating enzyme Ubc9, but the functional relevance of this association has not been assessed. Here, we show that DRIL1 is sumoylated both in vitro and in vivo at lysine 398. Moreover, we provide evidence that PIASy functions as a specific SUMO E3-ligase for DRIL1 and promotes its sumoylation both in vitro and in vivo. Furthermore, consistent with the subnuclear localization of PIASy in the Matrix-Associated Region (MAR), SUMO-modified DRIL1 species are found exclusively in the MAR fraction. This post-translational modification interferes neither with the subcellular localization nor the DNA-binding activity of the protein. In contrast, DRIL1 sumoylation impairs its interaction with E2F1 in vitro and modifies its transcriptional activity in vivo, driving transcription of subset of genes regulating leukocyte fate. Taken together, these results identify sumoylation as a novel post-translational modification of DRIL1 that represents an important mechanism for targeting and modulating DRIL1 transcriptional activity. PMID:19436740

Sumoylation activates the transcriptional activity of Pax-6, an important transcription factor for eye and brain development

PubMed Central

Yan, Qin; Gong, Lili; Deng, Mi; Zhang, Lan; Sun, Shuming; Liu, Jiao; Ma, Haili; Yuan, Dan; Chen, Pei-Chao; Hu, Xiaohui; Liu, Jinping; Qin, Jichao; Xiao, Ling; Huang, Xiao-Qin; Zhang, Jian; Wan-Cheng Li, David

2010-01-01

Pax-6 is an evolutionarily conserved transcription factor regulating brain and eye development. Four Pax-6 isoforms have been reported previously. Although the longer Pax-6 isoforms (p46 and p48) bear two DNA-binding domains, the paired domain (PD) and the homeodomain (HD), the shorter Pax-6 isoform p32 contains only the HD for DNA binding. Although a third domain, the proline-, serine- and threonine-enriched activation (PST) domain, in the C termini of all Pax-6 isoforms mediates their transcriptional modulation via phosphorylation, how p32 Pax-6 could regulate target genes remains to be elucidated. In the present study, we show that sumoylation at K91 is required for p32 Pax-6 to bind to a HD-specific site and regulate expression of target genes. First, in vitro-synthesized p32 Pax-6 alone cannot bind the P3 sequence, which contains the HD recognition site, unless it is preincubated with nuclear extracts precleared by anti–Pax-6 but not by anti-small ubiquitin-related modifier 1 (anti-SUMO1) antibody. Second, in vitro-synthesized p32 Pax-6 can be sumoylated by SUMO1, and the sumoylated p32 Pax-6 then can bind to the P3 sequence. Third, Pax-6 and SUMO1 are colocalized in the embryonic optic and lens vesicles and can be coimmunoprecipitated. Finally, SUMO1-conjugated p32 Pax-6 exists in both the nucleus and cytoplasm, and sumoylation significantly enhances the DNA-binding ability of p32 Pax-6 and positively regulates gene expression. Together, our results demonstrate that sumoylation activates p32 Pax-6 in both DNA-binding and transcriptional activities. In addition, our studies demonstrate that p32 and p46 Pax-6 possess differential DNA-binding and regulatory activities. PMID:21084637

Both conditional ablation and overexpression of E2 SUMO-conjugating enzyme (UBC9) in mouse pancreatic beta cells result in impaired beta cell function.

PubMed

He, Xiaoyu; Lai, Qiaohong; Chen, Cai; Li, Na; Sun, Fei; Huang, Wenting; Zhang, Shu; Yu, Qilin; Yang, Ping; Xiong, Fei; Chen, Zhishui; Gong, Quan; Ren, Boxu; Weng, Jianping; Eizirik, Décio L; Zhou, Zhiguang; Wang, Cong-Yi

2018-04-01

Post-translational attachment of a small ubiquitin-like modifier (SUMO) to the lysine (K) residue(s) of target proteins (SUMOylation) is an evolutionary conserved regulatory mechanism. This modification has previously been demonstrated to be implicated in the control of a remarkably versatile regulatory mechanism of cellular processes. However, the exact regulatory role and biological actions of the E2 SUMO-conjugating enzyme (UBC9)-mediated SUMOylation function in pancreatic beta cells has remained elusive. Inducible beta cell-specific Ubc9 (also known as Ube2i) knockout (KO; Ubc9 Δbeta ) and transgenic (Ubc9 Tg ) mice were employed to address the impact of SUMOylation on beta cell viability and functionality. Ubc9 deficiency or overexpression was induced at 8 weeks of age using tamoxifen. To study the mechanism involved, we closely examined the regulation of the transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) through SUMOylation in beta cells. Upon induction of Ubc9 deficiency, Ubc9 Δbeta islets exhibited a 3.5-fold higher accumulation of reactive oxygen species (ROS) than Ubc9 f/f control islets. Islets from Ubc9 Δbeta mice also had decreased insulin content and loss of beta cell mass after tamoxifen treatment. Specifically, at day 45 after Ubc9 deletion only 40% of beta cell mass remained in Ubc9 Δbeta mice, while 90% of beta cell mass was lost by day 75. Diabetes onset was noted in some Ubc9 Δbeta mice 8 weeks after induction of Ubc9 deficiency and all mice developed diabetes by 10 weeks following tamoxifen treatment. In contrast, Ubc9 Tg beta cells displayed an increased antioxidant ability but impaired insulin secretion. Unlike Ubc9 Δbeta mice, which spontaneously developed diabetes, Ubc9 Tg mice preserved normal non-fasting blood glucose levels without developing diabetes. It was noted that SUMOylation of NRF2 promoted its nuclear expression along with enhanced transcriptional activity, thereby preventing ROS accumulation in beta cells. SUMOylation function is required to protect against oxidative stress in beta cells; this mechanism is, at least in part, carried out by the regulation of NRF2 activity to enhance ROS detoxification. Homeostatic SUMOylation is also likely to be essential for maintaining beta cell functionality.

PML, SUMOylation, and Senescence

PubMed Central

Ivanschitz, Lisa; De Thé, Hugues; Le Bras, Morgane

2013-01-01

Since its discovery, 25 years ago, promyelocytic leukemia (PML) has been an enigma. Implicated in the oncogenic PML/RARA fusion, forming elusive intranuclear domains, triggering cell death or senescence, controlled by and perhaps controlling SUMOylation… there are multiple PML-related issues. Here we review the reciprocal interactions between PML, senescence, and SUMOylation, notably in the context of cellular transformation. PMID:23847762

Inducible SUMO modification of TANK alleviates its repression of TLR7 signalling.

PubMed

Renner, Florian; Saul, Vera V; Pagenstecher, Axel; Wittwer, Tobias; Schmitz, Michael Lienhard

2011-02-01

Adaptor proteins allow temporal and spatial coordination of signalling. In this study, we show SUMOylation of the adaptor protein TANK and its interacting kinase TANK-binding kinase 1 (TBK1). Modification of TANK by the small ubiquitin-related modifier (SUMO) at the evolutionarily conserved Lys 282 is triggered by the kinase activities of IκB kinase ɛ (IKKɛ) and TBK1. Stimulation of TLR7 leads to inducible SUMOylation of TANK, which in turn weakens the interaction with IKKɛ and thus relieves the negative function of TANK on signal propagation. Reconstitution experiments show that an absence of TANK SUMOylation impairs inducible expression of distinct TLR7-dependent target genes, providing a molecular mechanism that allows the control of TANK function.

SUMO-Specific Cysteine Protease 1 Promotes Epithelial Mesenchymal Transition of Prostate Cancer Cells via Regulating SMAD4 deSUMOylation.

PubMed

Zhang, Xiaoyan; Wang, Hao; Wang, Hua; Xiao, Fengjun; Seth, Prem; Xu, Weidong; Jia, Qinghua; Wu, Chutse; Yang, Yuefeng; Wang, Lisheng

2017-04-12

In advanced prostate cancer, small ubiquitin-like modifier (SUMO)-specific cysteine protease 1 (SENP1) is up-regulated. However, the role of SENP1 in regulating deSUMOylation of TGF-β/SMADs signaling is unknown. In this study, we developed a lentiviral vector, PLKO.1-shSENP1, to silence SENP1 in prostate cancer cells with high metastatic characteristics (PC3M). Likewise, we also created an adenovirus vector, Ad5/F11p-SENP1 to over-express SENP1 in prostate cancer cells with low metastatic potential (LNCaP). We showed that silencing of SENP1 promoted cellular apoptosis, and inhibited proliferation and migration of PC3M cells. Moreover, SENP1 silencing increased the SMAD4 expression at protein level, up-regulated E-cadherin and down-regulated Vimentin expression, indicating the inhibition of epithelial mesenchymal transition (EMT). Furthermore, SMAD4 interference abolished SENP1-mediated up-regulation of E-cadherin, suggesting that SENP1 regulated E-cadherin expression via SMAD4. SENP1 over-expression in LNCaP cells reduced SMAD4 protein, and promoted EMT via decreasing E-cadherin and increasing Vimentin. Moreover, down-regulation of SMAD4 and E-cadherin were blocked, after transfection with two SUMOylation sites mutated SMAD4, suggesting that SENP1 might reduce SMAD4 levels to regulate E-cadherin expression via deSUMOylation of SMAD4. In conclusion, SENP1 deSUMOylated SMAD4 to promote EMT via up-regulating E-cadherin in prostate cancer cells. Therefore, SENP1 is a potential target for treatment of advanced prostate cancer.

Sumoylation of Sir2 differentially regulates transcriptional silencing in yeast.

PubMed

Hannan, Abdul; Abraham, Neethu Maria; Goyal, Siddharth; Jamir, Imlitoshi; Priyakumar, U Deva; Mishra, Krishnaveni

2015-12-02

Silent information regulator 2 (Sir2), the founding member of the conserved sirtuin family of NAD(+)-dependent histone deacetylase, regulates several physiological processes including genome stability, gene silencing, metabolism and life span in yeast. Within the nucleus, Sir2 is associated with telomere clusters in the nuclear periphery and rDNA in the nucleolus and regulates gene silencing at these genomic sites. How distribution of Sir2 between telomere and rDNA is regulated is not known. Here we show that Sir2 is sumoylated and this modification modulates the intra-nuclear distribution of Sir2. We identify Siz2 as the key SUMO ligase and show that multiple lysines in Sir2 are subject to this sumoylation activity. Mutating K215 alone counteracts the inhibitory effect of Siz2 on telomeric silencing. SUMO modification of Sir2 impairs interaction with Sir4 but not Net1 and, furthermore, SUMO modified Sir2 shows predominant nucleolar localization. Our findings demonstrate that sumoylation of Sir2 modulates distribution between telomeres and rDNA and this is likely to have implications for Sir2 function in other loci as well. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

An arginine-rich motif of ring finger protein 4 (RNF4) oversees the recruitment and degradation of the phosphorylated and SUMOylated Krüppel-associated box domain-associated protein 1 (KAP1)/TRIM28 protein during genotoxic stress.

PubMed

Kuo, Ching-Ying; Li, Xu; Kong, Xiang-Qian; Luo, Cheng; Chang, Che-Chang; Chung, Yiyin; Shih, Hsiu-Ming; Li, Keqin Kathy; Ann, David K

2014-07-25

Krüppel-associated box domain-associated protein 1 (KAP1) is a universal transcriptional corepressor that undergoes multiple posttranslational modifications (PTMs), including SUMOylation and Ser-824 phosphorylation. However, the functional interplay of KAP1 PTMs in regulating KAP1 turnover during DNA damage response remains unclear. To decipher the role and cross-talk of multiple KAP1 PTMs, we show here that DNA double strand break-induced KAP1 Ser-824 phosphorylation promoted the recruitment of small ubiquitin-like modifier (SUMO)-targeted ubiquitin E3 ligase, ring finger protein 4 (RNF4), and subsequent RNF4-mediated, SUMO-dependent degradation. Besides the SUMO interacting motif (SIM), a previously unrecognized, but evolutionarily conserved, arginine-rich motif (ARM) in RNF4 acts as a novel recognition motif for selective target recruitment. Results from combined mutagenesis and computational modeling studies suggest that RNF4 utilizes concerted bimodular recognition, namely SIM for Lys-676 SUMOylation and ARM for Ser(P)-824 of simultaneously phosphorylated and SUMOylated KAP1 (Ser(P)-824-SUMO-KAP1). Furthermore, we proved that arginines 73 and 74 within the ARM of RNF4 are required for efficient recruitment to KAP1 or accelerated degradation of promyelocytic leukemia protein (PML) under stress. In parallel, results of bimolecular fluorescence complementation assays validated the role of the ARM in recognizing Ser(P)-824 in living cells. Taken together, we establish that the ARM is required for RNF4 to efficiently target Ser(P)-824-SUMO-KAP1, conferring ubiquitin Lys-48-mediated proteasomal degradation in the context of double strand breaks. The conservation of such a motif may possibly explain the requirement for timely substrate selectivity determination among a myriad of SUMOylated proteins under stress conditions. Thus, the ARM dynamically regulates the SIM-dependent recruitment of targets to RNF4, which could be critical to dynamically fine-tune the abundance of Ser(P)-824-SUMO-KAP1 and, potentially, other SUMOylated proteins during DNA damage response. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

An Arginine-rich Motif of Ring Finger Protein 4 (RNF4) Oversees the Recruitment and Degradation of the Phosphorylated and SUMOylated Krüppel-associated Box Domain-associated Protein 1 (KAP1)/TRIM28 Protein during Genotoxic Stress*

PubMed Central

Kuo, Ching-Ying; Li, Xu; Kong, Xiang-Qian; Luo, Cheng; Chang, Che-Chang; Chung, Yiyin; Shih, Hsiu-Ming; Li, Keqin Kathy; Ann, David K.

2014-01-01

Krüppel-associated box domain-associated protein 1 (KAP1) is a universal transcriptional corepressor that undergoes multiple posttranslational modifications (PTMs), including SUMOylation and Ser-824 phosphorylation. However, the functional interplay of KAP1 PTMs in regulating KAP1 turnover during DNA damage response remains unclear. To decipher the role and cross-talk of multiple KAP1 PTMs, we show here that DNA double strand break-induced KAP1 Ser-824 phosphorylation promoted the recruitment of small ubiquitin-like modifier (SUMO)-targeted ubiquitin E3 ligase, ring finger protein 4 (RNF4), and subsequent RNF4-mediated, SUMO-dependent degradation. Besides the SUMO interacting motif (SIM), a previously unrecognized, but evolutionarily conserved, arginine-rich motif (ARM) in RNF4 acts as a novel recognition motif for selective target recruitment. Results from combined mutagenesis and computational modeling studies suggest that RNF4 utilizes concerted bimodular recognition, namely SIM for Lys-676 SUMOylation and ARM for Ser(P)-824 of simultaneously phosphorylated and SUMOylated KAP1 (Ser(P)-824-SUMO-KAP1). Furthermore, we proved that arginines 73 and 74 within the ARM of RNF4 are required for efficient recruitment to KAP1 or accelerated degradation of promyelocytic leukemia protein (PML) under stress. In parallel, results of bimolecular fluorescence complementation assays validated the role of the ARM in recognizing Ser(P)-824 in living cells. Taken together, we establish that the ARM is required for RNF4 to efficiently target Ser(P)-824-SUMO-KAP1, conferring ubiquitin Lys-48-mediated proteasomal degradation in the context of double strand breaks. The conservation of such a motif may possibly explain the requirement for timely substrate selectivity determination among a myriad of SUMOylated proteins under stress conditions. Thus, the ARM dynamically regulates the SIM-dependent recruitment of targets to RNF4, which could be critical to dynamically fine-tune the abundance of Ser(P)-824-SUMO-KAP1 and, potentially, other SUMOylated proteins during DNA damage response. PMID:24907272

The yeast homologue of the microtubule-associated protein Lis1 interacts with the sumoylation machinery and a SUMO-targeted ubiquitin ligase

PubMed Central

Alonso, Annabel; D'Silva, Sonia; Rahman, Maliha; Meluh, Pam B.; Keeling, Jacob; Meednu, Nida; Hoops, Harold J.; Miller, Rita K.

2012-01-01

Microtubules and microtubule-associated proteins are fundamental for multiple cellular processes, including mitosis and intracellular motility, but the factors that control microtubule-associated proteins (MAPs) are poorly understood. Here we show that two MAPs—the CLIP-170 homologue Bik1p and the Lis1 homologue Pac1p—interact with several proteins in the sumoylation pathway. Bik1p and Pac1p interact with Smt3p, the yeast SUMO; Ubc9p, an E2; and Nfi1p, an E3. Bik1p interacts directly with SUMO in vitro, and overexpression of Smt3p and Bik1p results in its in vivo sumoylation. Modified Pac1p is observed when the SUMO protease Ulp1p is inactivated. Both ubiquitin and Smt3p copurify with Pac1p. In contrast to ubiquitination, sumoylation does not directly tag the substrate for degradation. However, SUMO-targeted ubiquitin ligases (STUbLs) can recognize a sumoylated substrate and promote its degradation via ubiquitination and the proteasome. Both Pac1p and Bik1p interact with the STUbL Nis1p-Ris1p and the protease Wss1p. Strains deleted for RIS1 or WSS1 accumulate Pac1p conjugates. This suggests a novel model in which the abundance of these MAPs may be regulated via STUbLs. Pac1p modification is also altered by Kar9p and the dynein regulator She1p. This work has implications for the regulation of dynein's interaction with various cargoes, including its off-loading to the cortex. PMID:23034179

Luteolin Modulates SERCA2a Leading to Attenuation of Myocardial Ischemia/ Reperfusion Injury via Sumoylation at Lysine 585 in Mice.

PubMed

Du, Yinping; Liu, Ping; Xu, Tongda; Pan, Defeng; Zhu, Hong; Zhai, Nana; Zhang, Yanbin; Li, Dongye

2018-01-01

The myocardial sarcoplasmic reticulum calcium ATPase (SERCA2a) is a pivotal pump responsible for calcium cycling in cardiomyocytes. The present study investigated the effect of luteolin (Lut) on restoring SERCA2a protein level and stability reduced by myocardial ischemia/reperfusion (I/R) injury. We verified a hypothesis that Lut protected against myocardial I/R injury by regulating SERCA2a SUMOylation. The hemodynamic data, myocardial infarct size of intact hearts, apoptotic analysis, mitochondrial membrane potential (ΔΨm), the level of SERCA2a SUMOylation, and the activity and expression of SERCA2a were examined in vivo and in vitro to clarify the cardioprotective effects of Lut after SUMO1 was knocked down or over-expressed. The putative SUMO conjugation sites in mouse SERCA2a were investigated as the possible regulatory mechanism of Lut. Initially, we found that Lut reversed the SUMOylation and stability of SERCA2a as well as the expression of SUMO1, which were reduced by I/R injury in vitro. Furthermore, Lut increased the expression and activity of SERCA2a partly through SUMO1, thus improving ΔΨm and reducing apoptotic cells in vitro and promoting the recovery of heart function and reducing infarct size in vivo. We also demonstrated that SUMO acceptor sites in mouse SERCA2a involving lysine 585, 480 and 571. Among the three acceptor sites, Lut enhanced SERCA2a stability via lysine 585. Our results suggest that Lut regulates SERCA2a through SUMOylation at lysine 585 to attenuate myocardial I/R injury. © 2018 The Author(s). Published by S. Karger AG, Basel.

SUMO-Specific Cysteine Protease 1 Promotes Epithelial Mesenchymal Transition of Prostate Cancer Cells via Regulating SMAD4 deSUMOylation

PubMed Central

Zhang, Xiaoyan; Wang, Hao; Wang, Hua; Xiao, Fengjun; Seth, Prem; Xu, Weidong; Jia, Qinghua; Wu, Chutse; Yang, Yuefeng; Wang, Lisheng

2017-01-01

In advanced prostate cancer, small ubiquitin-like modifier (SUMO)-specific cysteine protease 1 (SENP1) is up-regulated. However, the role of SENP1 in regulating deSUMOylation of TGF-β/SMADs signaling is unknown. In this study, we developed a lentiviral vector, PLKO.1-shSENP1, to silence SENP1 in prostate cancer cells with high metastatic characteristics (PC3M). Likewise, we also created an adenovirus vector, Ad5/F11p-SENP1 to over-express SENP1 in prostate cancer cells with low metastatic potential (LNCaP). We showed that silencing of SENP1 promoted cellular apoptosis, and inhibited proliferation and migration of PC3M cells. Moreover, SENP1 silencing increased the SMAD4 expression at protein level, up-regulated E-cadherin and down-regulated Vimentin expression, indicating the inhibition of epithelial mesenchymal transition (EMT). Furthermore, SMAD4 interference abolished SENP1-mediated up-regulation of E-cadherin, suggesting that SENP1 regulated E-cadherin expression via SMAD4. SENP1 over-expression in LNCaP cells reduced SMAD4 protein, and promoted EMT via decreasing E-cadherin and increasing Vimentin. Moreover, down-regulation of SMAD4 and E-cadherin were blocked, after transfection with two SUMOylation sites mutated SMAD4, suggesting that SENP1 might reduce SMAD4 levels to regulate E-cadherin expression via deSUMOylation of SMAD4. In conclusion, SENP1 deSUMOylated SMAD4 to promote EMT via up-regulating E-cadherin in prostate cancer cells. Therefore, SENP1 is a potential target for treatment of advanced prostate cancer. PMID:28417919

The GTP-bound and Sumoylated Form of the rab17 Small Molecular Weight GTPase Selectively Binds Syntaxin 2 in Polarized Hepatic WIF-B Cells*

PubMed Central

Striz, Anneliese C.; Tuma, Pamela L.

2016-01-01

A major focus for our laboratory is identifying the molecules and mechanisms that regulate polarized apical protein sorting in hepatocytes, the major epithelial cells of the liver. These trafficking pathways are regulated, in part, by small molecular weight rab GTPases. We chose to investigate rab17, whose expression is restricted to polarized epithelial cells, is enriched in liver, and has been implicated in regulating basolateral to apical transcytosis. To initiate our studies, we generated three recombinant adenoviruses expressing wild type, constitutively active (GTP bound), or dominant-negative (GDP bound) rab17. Immunoblotting revealed rab17 immunoreactive species at 25 kDa (the predicted rab17 molecular mass) and 40 kDa. We determined that mono-sumoylation of the 25-kDa rab17 is responsible for the shift in molecular mass, and that rab17 prenylation is required for sumoylation. We further determined that sumoylation selectively promotes interactions with syntaxin 2 (but not syntaxins 3 or 4) and that these interactions are nucleotide dependent. Furthermore, a K68R-mutated rab17 led to the redistribution of syntaxin 2 and 5′ nucleotidase from the apical membrane to subapical puncta, whereas multidrug resistance protein 2 distributions were not changed. Together these data are consistent with the proposed role of rab17 in vesicle fusion with the apical plasma membrane and further implicate sumoylation as an important mediator of protein-protein interactions. The selectivity in syntaxin binding and apical protein redistribution further suggests that rab17 and syntaxin 2 mediate fusion of transcytotic vesicles at the apical surface. PMID:26957544

SUMOylation Regulates the Homologous to E6-AP Carboxyl Terminus (HECT) Ubiquitin Ligase Rsp5p*

PubMed Central

Novoselova, Tatiana Vladislavovna; Rose, Ruth-Sarah; Marks, Helen Margaret; Sullivan, James Andrew

2013-01-01

The post-translational modifiers ubiquitin and small ubiquitin-related modifier (SUMO) regulate numerous critical signaling pathways and are key to controlling the cellular fate of proteins in eukaryotes. The attachment of ubiquitin and SUMO involves distinct, but related, machinery. However, it is now apparent that many substrates can be modified by both ubiquitin and SUMO and that some regulatory interaction takes place between the respective attachment machinery. Here, we demonstrate that the Saccharomyces cerevisiae ubiquitin ligase Rsp5p, a member of the highly conserved Nedd4 family of ubiquitin ligases, is SUMOylated in vivo. We further show that Rsp5p SUMOylation is mediated by the SUMO ligases Siz1p and Siz2p, members of the conserved family of PIAS SUMO ligases that are, in turn, substrates for Rsp5p-mediated ubiquitylation. Our experiments show that SUMOylated Rsp5p has reduced ubiquitin ligase activity, and similarly, ubiquitylated Siz1p demonstrates reduced SUMO ligase activity leading to respective changes in both ubiquitin-mediated sorting of the manganese transporter Smf1p and polySUMO chain formation. This reciprocal regulation of these highly conserved ligases represents an exciting and previously unidentified system of cross talk between the ubiquitin and SUMO systems. PMID:23443663

SUMO proteases as potential targets for cancer therapy.

PubMed

Bialik, Piotr; Woźniak, Katarzyna

2017-12-08

Sumoylation is one of the post-translational modifications of proteins, responsible for the regulation of many cellular processes, such as DNA replication and repair, transcription, signal transduction and nuclear transport. During sumoylation, SUMO proteins are covalently attached to the ε-amino group of lysine in target proteins via an enzymatic cascade that requires the sequential action of E1, E2 and E3 enzymes. An important aspect of sumoylation is its reversibility, which involves SUMO-specific proteases called SENPs. SENPs (sentrin/SUMO-specific proteases) catalyze the deconjugation of SUMO proteins using their isopeptidase activity. These enzymes participate through hydrolase activity in the reaction of SUMO protein maturation, which involves the removal of a short fragment on the C-terminus of SUMO inactive form and exposure two glycine residues. SENPs are important for maintaining the balance between sumoylated and desumoylated proteins required for normal cellular physiology. Six SENP isoforms (SENP1, SENP2, SENP3, SENP5, SENP6 and SENP7) have been identified in mammals. These SENPs can be divided into three subfamilies based on their sequence homology, substrate specificity and subcellular localization. Results of studies indicate the role of SUMO proteases in the development of human diseases including cancer, suggesting that these proteins may be attractive targets for new drugs.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seo, Jae Sung; Kim, Ha Na; Kim, Sun-Jick

Highlights: •NuMA is modified by SUMO-1 in a cell cycle-dependent manner. •NuMA lysine 1766 is the primary target site for SUMOylation. •SUMOylation-deficient NuMA induces multiple spindle poles during mitosis. •SUMOylated NuMA induces microtubule bundling. -- Abstract: Covalent conjugation of proteins with small ubiquitin-like modifier 1 (SUMO-1) plays a critical role in a variety of cellular functions including cell cycle control, replication, and transcriptional regulation. Nuclear mitotic apparatus protein (NuMA) localizes to spindle poles during mitosis, and is an essential component in the formation and maintenance of mitotic spindle poles. Here we show that NuMA is a target for covalent conjugationmore » to SUMO-1. We find that the lysine 1766 residue is the primary NuMA acceptor site for SUMO-1 conjugation. Interestingly, SUMO modification of endogenous NuMA occurs at the entry into mitosis and this modification is reversed after exiting from mitosis. Knockdown of Ubc9 or forced expression of SENP1 results in impairment of the localization of NuMA to mitotic spindle poles during mitosis. The SUMOylation-deficient NuMA mutant is defective in microtubule bundling, and multiple spindles are induced during mitosis. The mitosis-dependent dynamic SUMO-1 modification of NuMA might contribute to NuMA-mediated formation and maintenance of mitotic spindle poles during mitosis.« less

SUMO-Enriched Proteome for Drosophila Innate Immune Response

PubMed Central

Handu, Mithila; Kaduskar, Bhagyashree; Ravindranathan, Ramya; Soory, Amarendranath; Giri, Ritika; Elango, Vijay Barathi; Gowda, Harsha; Ratnaparkhi, Girish S.

2015-01-01

Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens. PMID:26290570

SUMO-Enriched Proteome for Drosophila Innate Immune Response.

PubMed

Handu, Mithila; Kaduskar, Bhagyashree; Ravindranathan, Ramya; Soory, Amarendranath; Giri, Ritika; Elango, Vijay Barathi; Gowda, Harsha; Ratnaparkhi, Girish S

2015-08-18

Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens. Copyright © 2015 Handu et al.

A mediator methylation mystery: JMJD1C demethylates MDC1 to regulate DNA repair.

PubMed

Lu, Jian; Matunis, Michael J

2013-12-01

Mediator of DNA-damage checkpoint 1 (MDMDC1) has a central role in repair of DNA double-strand breaks (DSBs) by both homologous recombination and nonhomologous end joining, and its function is regulated by post-translational phosphorylation, ubiquitylation and sumoylation. In this issue, a new study by Watanabe et al. reveals that methylation of MDMDC1 is also critical for its function in DSB repair and specifically affects repair through BRCA1-dependent homologous recombination.

Quantitative SUMO proteomics reveals the modulation of several PML nuclear body associated proteins and an anti-senescence function of UBC9.

PubMed

McManus, Francis P; Bourdeau, Véronique; Acevedo, Mariana; Lopes-Paciencia, Stéphane; Mignacca, Lian; Lamoliatte, Frédéric; Rojas Pino, John W; Ferbeyre, Gerardo; Thibault, Pierre

2018-05-17

Several regulators of SUMOylation have been previously linked to senescence but most targets of this modification in senescent cells remain unidentified. Using a two-step purification of a modified SUMO3, we profiled the SUMO proteome of senescent cells in a site-specific manner. We identified 25 SUMO sites on 23 proteins that were significantly regulated during senescence. Of note, most of these proteins were PML nuclear body (PML-NB) associated, which correlates with the increased number and size of PML-NBs observed in senescent cells. Interestingly, the sole SUMO E2 enzyme, UBC9, was more SUMOylated during senescence on its Lys-49. Functional studies of a UBC9 mutant at Lys-49 showed a decreased association to PML-NBs and the loss of UBC9's ability to delay senescence. We thus propose both pro- and anti-senescence functions of protein SUMOylation.

High glucose induces activation of NF-κB inflammatory signaling through IκBα sumoylation in rat mesangial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Wei; Department of Endocrinology, The People’s Hospital of Xindu, Xindu, Sichuang, 610500; Xu, Ling

Highlights: •The expression of SUMO1, SUMO2/3 under high glucose was obviously enhanced. •High glucose induced degradation of IκBα and activation of NF-κB pathway. •Sumoylation of IκBα in high glucose were significantly decreased. •The proteasome inhibitor MG132 could partially revert the degradation of IκBα. -- Abstract: The posttranslational modification of proteins by small ubiquitin-like modifiers (SUMOs) has emerged as an important regulatory mechanism for the alteration of protein activity, stability, and cellular localization. The latest research demonstrates that sumoylation is extensively involved in the regulation of the nuclear factor κB (NF-κB) pathway, which plays a critical role in the regulation ofmore » inflammation and contributes to fibrosis in diabetic nephropathy (DN). However, the role of sumoylation in the regulation of NF-κB signaling in DN is still unclear. In the present study, we cultured rat glomerular mesangial cells (GMCs) stimulated by high glucose and divided GMCs into six groups: normal glucose group (5.6 mmol/L), high glucose groups (10, 20, and 30 mmol/L), mannitol group (i.e., osmotic control group), and MG132 intervention group (30 mmol/L glucose with MG132, a proteasome inhibitor). The expression of SUMO1, SUMO2/3, IκBα, NF-κBp65, and monocyte chemotactic protein 1 (MCP-1) was measured by Western blot, reverse-transcription polymerase chain reaction, and indirect immunofluorescence laser scanning confocal microscopy. The interaction between SUMO1, SUMO2/3, and IκBα was observed by co-immunoprecipitation. The results showed that the expression of SUMO1 and SUMO2/3 was dose- and time-dependently enhanced by high glucose (p < 0.05). However, the expression of IκBα sumoylation in high glucose was significantly decreased compared with the normal glucose group (p < 0.05). The expression of IκBα was dose- and time-dependently decreased, and NF-κBp65 and MCP-1 were increased under high glucose conditions, which could be mostly reversed by adding MG132 (p < 0.05). The present results support the hypothesis that high glucose may activate NF-κB inflammatory signaling through IκBα sumoylation and ubiquitination.« less

Novel signal transducer and activator of transcription 1 mutation disrupts small ubiquitin-related modifier conjugation causing gain of function.

PubMed

Sampaio, Elizabeth P; Ding, Li; Rose, Stacey R; Cruz, Phillip; Hsu, Amy P; Kashyap, Anuj; Rosen, Lindsey B; Smelkinson, Margery; Tavella, Tatyana A; Ferre, Elise M N; Wierman, Meredith K; Zerbe, Christa S; Lionakis, Michail S; Holland, Steven M

2018-05-01

Sumoylation is a posttranslational reversible modification of cellular proteins through the conjugation of small ubiquitin-related modifier (SUMO) and comprises an important regulator of protein function. We sought to characterize the molecular mechanism of a novel mutation at the SUMO motif on signal transducer and activator of transcription 1 (STAT1). STAT1 sequencing and functional characterization were performed in transfection experiments by using immunoblotting and immunoprecipitation in STAT1-deficient cell lines. Transcriptional response and target gene activation were also investigated in PBMCs. We identified a novel STAT1 mutation (c.2114A>T, p.E705V) within the SUMO motif ( 702 IKTE 705 ) in a patient with disseminated Rhodococcus species infection, Norwegian scabies, chronic mucocutaneous candidiasis, hypothyroidism, and esophageal squamous cell carcinoma. The mutation is located in the tail segment and is predicted to disrupt STAT1 sumoylation. Immunoprecipitation experiments performed in transfected cells confirmed absent STAT1 sumoylation for E705V, whereas it was present in wild-type (WT) STAT1 cells, as well as the loss-of-function mutants L706S and Y701C. Furthermore, stimulation with IFN-γ led to enhanced STAT1 phosphorylation, enhanced transcriptional activity, and target gene expression in the E705V-transfected compared with WT-transfected cells. Computer modeling of WT and mutant STAT1 molecules showed variations in the accessibility of the phosphorylation site Y701, which corresponded to the loss-of-function and gain-of-function variants. This is the first report of a mutation in the STAT1 sumoylation motif associated with clinical disease. These data reinforce sumoylation as a key posttranslational regulatory modification of STAT1 and identify a novel mechanism for gain-of-function STAT1 disease in human subjects. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.

The adenovirus E4-ORF3 protein functions as a SUMO E3 ligase for TIF-1γ sumoylation and poly-SUMO chain elongation.

PubMed

Sohn, Sook-Young; Hearing, Patrick

2016-06-14

The adenovirus (Ad) early region 4 (E4)-ORF3 protein regulates diverse cellular processes to optimize the host environment for the establishment of Ad replication. E4-ORF3 self-assembles into multimers to form a nuclear scaffold in infected cells and creates distinct binding interfaces for different cellular target proteins. Previous studies have shown that the Ad5 E4-ORF3 protein induces sumoylation of multiple cellular proteins and subsequent proteasomal degradation of some of them, but the detailed mechanism of E4-ORF3 function remained unknown. Here, we investigate the role of E4-ORF3 in the sumoylation process by using transcription intermediary factor (TIF)-1γ as a substrate. Remarkably, we discovered that purified E4-ORF3 protein stimulates TIF-1γ sumoylation in vitro, demonstrating that E4-ORF3 acts as a small ubiquitin-like modifier (SUMO) E3 ligase. Furthermore, E4-ORF3 significantly increases poly-SUMO3 chain formation in vitro in the absence of substrate, showing that E4-ORF3 has SUMO E4 elongase activity. An E4-ORF3 mutant, which is defective in protein multimerization, exhibited severely decreased activity, demonstrating that E4-ORF3 self-assembly is required for these activities. Using a SUMO3 mutant, K11R, we found that E4-ORF3 facilitates the initial acceptor SUMO3 conjugation to TIF-1γ as well as poly-SUMO chain elongation. The E4-ORF3 protein displays no SUMO-targeted ubiquitin ligase activity in our assay system. These studies reveal the mechanism by which E4-ORF3 targets specific cellular proteins for sumoylation and proteasomal degradation and provide significant insight into how a small viral protein can play a role as a SUMO E3 ligase and E4-like SUMO elongase to impact a variety of cellular responses.

Lamin A reassembly at the end of mitosis is regulated by its SUMO-interacting motif

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moriuchi, Takanobu; Kuroda, Masaki; Kusumoto, Fumiya

Modification of proteins with small ubiquitin-related modifier (SUMO; SUMOylation) is involved in the regulation of various biological processes. Recent studies have demonstrated that noncovalent associations between SUMOylated proteins and co-operative proteins containing SUMO-interacting motifs (SIMs) are important for the spatiotemporal organization of many protein complexes. In this study, we demonstrate that interactions between lamin A, a major component of the nuclear lamina, and SUMO isoforms are dependent on one of the four SIMs (SIM3) resided in lamin A polypeptide in vitro. Live cell imaging and immunofluorescence staining showed that SIM3 is required for accumulation of lamin A on the chromosomesmore » during telophase, and subsequent evaluation of a panel of deletion mutants determined that a 156-amino acid region spanning the carboxyl-terminal Ig-fold domain of lamin A is sufficient for this accumulation. Notably, mutation of SIM3 abrogated the dephosphorylation of mitosis-specific phosphorylation at Ser-22 of lamin A, which normally occurs during telophase, and the subsequent nuclear lamina reorganization. Furthermore, expression of a conjugation-defective SUMO2 mutant, which was previously shown to inhibit endogenous SUMOylation in a dominant-negative manner, also impaired the accumulation of wild type lamin A on telophase chromosomes. These findings suggest that interactions between SIM3 of lamin A and a putative SUMO2-modified protein plays an important role in the reorganization of the nuclear lamina at the end of mitosis. - Highlights: • Lamin A interacts with SUMO2 via a SUMO-interacting motif (SIM) in the Ig domain. • SIM3 of lamin A is responsible for chromosomal accumulation during telophase. • A 156-aa region spanning the Ig domain is sufficient for chromosomal accumulation. • Accumulation of lamin A is required for timely dephosphorylation on chromosomes. • A putative SUMO2-modified protein may mediate chromosomal accumulation of lamin A.« less

Nuclear pool of phosphatidylinositol 4 phosphate 5 kinase 1α is modified by polySUMO-2 during apoptosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chakrabarti, Rajarshi; Bhowmick, Debajit; Bhargava, Varsha

2013-09-20

Highlights: •Nuclear pool of PIP5K is SUMOylated. •Enhancement of SUMOylated nuclear PIP5K during apoptosis. •Nuclear PIP5K is modified by polySUMO-1 during apoptosis. •Nuclear PIP5K is modified by polySUMO-2 chain during apoptosis. -- Abstract: Phosphatidylinositol 4 phosphate 5 kinase 1α (PIP5K) is mainly localized in the cytosol and plasma membrane. Studies have also indicated its prominent association with nuclear speckles. The exact nature of this nuclear pool of PIP5K is not clear. Using biochemical and microscopic techniques, we have demonstrated that the nuclear pool of PIP5K is modified by SUMO-1 in HEK-293 cells stably expressing PIP5K. Moreover, this SUMOylated pool ofmore » PIP5K increased during apoptosis. PolySUMO-2 chain conjugated PIP5K was detected by pull-down experiment using affinity-tagged RNF4, a polySUMO-2 binding protein, during late apoptosis.« less

Identification of sumoylation activating enzyme 1 inhibitors by structure-based virtual screening.

PubMed

Kumar, Ashutosh; Ito, Akihiro; Hirohama, Mikako; Yoshida, Minoru; Zhang, Kam Y J

2013-04-22

SUMO activating enzyme 1 (SUMO E1) is responsible for the activation of SUMO in the first step of the sumoylation cascade. SUMO E1 is linked to many human diseases including cancer, thus making it a potential therapeutic target. There are few reported SUMO E1 inhibitors including several natural products. To identify small molecule inhibitors of SUMO E1 with better drug-like properties for potential therapeutic studies, we have used structure-based virtual screening to identify hits from the Maybridge small molecule library for biological assay. Our virtual screening protocol involves fast docking of the entire small molecule library with rigid protein and ligands followed by redocking of top hits using a method that incorporates both ligand and protein flexibility. Subsequently, the top-ranking compounds were prioritized using the molecular dynamics simulation-based binding free energy calculation. Out of 24 compounds that were acquired and tested using in vitro sumoylation assay, four of them showed more than 85% inhibition of sumoylation with the most active compound showing an IC50 of 14.4 μM. A similarity search with the most active compound in the ZINC database has identified three more compounds with improved potency. These compounds share a common phenyl urea scaffold and have been confirmed to inhibit SUMO E1 by in vitro SUMO-1 thioester bond formation assay. Our study suggests that these phenyl urea compounds could be used as a starting point for the development of novel therapeutic agents.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sekhri, Palak; Tao, Tao; Kaplan, Feige

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 andmore » 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.« less

SUMO1 Affects Synaptic Function, Spine Density and Memory

PubMed Central

Matsuzaki, Shinsuke; Lee, Linda; Knock, Erin; Srikumar, Tharan; Sakurai, Mikako; Hazrati, Lili-Naz; Katayama, Taiichi; Staniszewski, Agnieszka; Raught, Brian; Arancio, Ottavio; Fraser, Paul E.

2015-01-01

Small ubiquitin-like modifier-1 (SUMO1) plays a number of roles in cellular events and recent evidence has given momentum for its contributions to neuronal development and function. Here, we have generated a SUMO1 transgenic mouse model with exclusive overexpression in neurons in an effort to identify in vivo conjugation targets and the functional consequences of their SUMOylation. A high-expressing line was examined which displayed elevated levels of mono-SUMO1 and increased high molecular weight conjugates in all brain regions. Immunoprecipitation of SUMOylated proteins from total brain extract and proteomic analysis revealed ~95 candidate proteins from a variety of functional classes, including a number of synaptic and cytoskeletal proteins. SUMO1 modification of synaptotagmin-1 was found to be elevated as compared to non-transgenic mice. This observation was associated with an age-dependent reduction in basal synaptic transmission and impaired presynaptic function as shown by altered paired pulse facilitation, as well as a decrease in spine density. The changes in neuronal function and morphology were also associated with a specific impairment in learning and memory while other behavioral features remained unchanged. These findings point to a significant contribution of SUMO1 modification on neuronal function which may have implications for mechanisms involved in mental retardation and neurodegeneration. PMID:26022678

An improved ChIP-seq peak detection system for simultaneously identifying post-translational modified transcription factors by combinatorial fusion, using SUMOylation as an example.

PubMed

Cheng, Chia-Yang; Chu, Chia-Han; Hsu, Hung-Wei; Hsu, Fang-Rong; Tang, Chung Yi; Wang, Wen-Ching; Kung, Hsing-Jien; Chang, Pei-Ching

2014-01-01

Post-translational modification (PTM) of transcriptional factors and chromatin remodelling proteins is recognized as a major mechanism by which transcriptional regulation occurs. Chromatin immunoprecipitation (ChIP) in combination with high-throughput sequencing (ChIP-seq) is being applied as a gold standard when studying the genome-wide binding sites of transcription factor (TFs). This has greatly improved our understanding of protein-DNA interactions on a genomic-wide scale. However, current ChIP-seq peak calling tools are not sufficiently sensitive and are unable to simultaneously identify post-translational modified TFs based on ChIP-seq analysis; this is largely due to the wide-spread presence of multiple modified TFs. Using SUMO-1 modification as an example; we describe here an improved approach that allows the simultaneous identification of the particular genomic binding regions of all TFs with SUMO-1 modification. Traditional peak calling methods are inadequate when identifying multiple TF binding sites that involve long genomic regions and therefore we designed a ChIP-seq processing pipeline for the detection of peaks via a combinatorial fusion method. Then, we annotate the peaks with known transcription factor binding sites (TFBS) using the Transfac Matrix Database (v7.0), which predicts potential SUMOylated TFs. Next, the peak calling result was further analyzed based on the promoter proximity, TFBS annotation, a literature review, and was validated by ChIP-real-time quantitative PCR (qPCR) and ChIP-reChIP real-time qPCR. The results show clearly that SUMOylated TFs are able to be pinpointed using our pipeline. A methodology is presented that analyzes SUMO-1 ChIP-seq patterns and predicts related TFs. Our analysis uses three peak calling tools. The fusion of these different tools increases the precision of the peak calling results. TFBS annotation method is able to predict potential SUMOylated TFs. Here, we offer a new approach that enhances ChIP-seq data analysis and allows the identification of multiple SUMOylated TF binding sites simultaneously, which can then be utilized for other functional PTM binding site prediction in future.

End-joining inhibition at telomeres requires the translocase and polySUMO-dependent ubiquitin ligase Uls1.

PubMed

Lescasse, Rachel; Pobiega, Sabrina; Callebaut, Isabelle; Marcand, Stéphane

2013-03-20

In eukaryotes, permanent inhibition of the non-homologous end joining (NHEJ) repair pathway at telomeres ensures that chromosome ends do not fuse. In budding yeast, binding of Rap1 to telomere repeats establishes NHEJ inhibition. Here, we show that the Uls1 protein is required for the maintenance of NHEJ inhibition at telomeres. Uls1 protein is a non-essential Swi2/Snf2-related translocase and a Small Ubiquitin-related Modifier (SUMO)-Targeted Ubiquitin Ligase (STUbL) with unknown targets. Loss of Uls1 results in telomere-telomere fusions. Uls1 requirement is alleviated by the absence of poly-SUMO chains and by rap1 alleles lacking SUMOylation sites. Furthermore, Uls1 limits the accumulation of Rap1 poly-SUMO conjugates. We propose that one of Uls1 functions is to clear non-functional poly-SUMOylated Rap1 molecules from telomeres to ensure the continuous efficiency of NHEJ inhibition. Since Uls1 is the only known STUbL with a translocase activity, it can be the general molecular sweeper for the clearance of poly-SUMOylated proteins on DNA in eukaryotes.

Partners in crime: The role of tandem modules in gene transcription.

PubMed

Sharma, Rajal; Zhou, Ming-Ming

2015-09-01

Histones and their modifications play an important role in the regulation of gene transcription. Numerous modifications, such as acetylation, phosphorylation, methylation, ubiquitination, and SUMOylation, have been described. These modifications almost always co-occur and thereby increase the combinatorial complexity of post-translational modification detection. The domains that recognize these histone modifications often occur in tandem in the context of larger proteins and complexes. The presence of multiple modifications can positively or negatively regulate the binding of these tandem domains, influencing downstream cellular function. Alternatively, these tandem domains can have novel functions from their independent parts. Here we summarize structural and functional information known about major tandem domains and their histone binding properties. An understanding of these interactions is key for the development of epigenetic therapy. © 2015 The Protein Society.

hnRNP K Coordinates Transcriptional Silencing by SETDB1 in Embryonic Stem Cells

PubMed Central

Thompson, Peter J.; Dulberg, Vered; Moon, Kyung-Mee; Foster, Leonard J.; Chen, Carol; Karimi, Mohammad M.; Lorincz, Matthew C.

2015-01-01

Retrotransposition of endogenous retroviruses (ERVs) poses a substantial threat to genome stability. Transcriptional silencing of a subset of these parasitic elements in early mouse embryonic and germ cell development is dependent upon the lysine methyltransferase SETDB1, which deposits H3K9 trimethylation (H3K9me3) and the co-repressor KAP1, which binds SETDB1 when SUMOylated. Here we identified the transcription co-factor hnRNP K as a novel binding partner of the SETDB1/KAP1 complex in mouse embryonic stem cells (mESCs) and show that hnRNP K is required for ERV silencing. RNAi-mediated knockdown of hnRNP K led to depletion of H3K9me3 at ERVs, concomitant with de-repression of proviral reporter constructs and specific ERV subfamilies, as well as a cohort of germline-specific genes directly targeted by SETDB1. While hnRNP K recruitment to ERVs is dependent upon KAP1, SETDB1 binding at these elements requires hnRNP K. Furthermore, an intact SUMO conjugation pathway is necessary for SETDB1 recruitment to proviral chromatin and depletion of hnRNP K resulted in reduced SUMOylation at ERVs. Taken together, these findings reveal a novel regulatory hierarchy governing SETDB1 recruitment and in turn, transcriptional silencing in mESCs. PMID:25611934

PCGF2 negatively regulates arsenic trioxide-induced PML-RARA protein degradation via UBE2I inhibition in NB4 cells.

PubMed

Jo, Sungsin; Lee, Young Lim; Kim, Sojin; Lee, Hongki; Chung, Heekyoung

2016-07-01

Arsenic trioxide (ATO) is a therapeutic agent for acute promyelocytic leukemia (APL) which induces PML-RARA protein degradation via enhanced UBE2I-mediated sumoylation. PCGF2, a Polycomb group protein, has been suggested as an anti-SUMO E3 protein by inhibiting the sumoylation of UBE2I substrates, HSF2 and RANGAP1, via direct interaction. Thus, we hypothesized that PCGF2 might play a role in ATO-induced PML-RARA degradation by interacting with UBE2I. PCGF2 protein was down-regulated upon ATO treatment in human APL cell line, NB4. Knockdown of PCGF2 in NB4 cells, in the absence of ATO treatment, was sufficient to induce sumoylation-, ubiquitylation- and PML nuclear body-mediated degradation of PML-RARA protein. Moreover, overexpression of PCGF2 protected ATO-mediated degradation of ectopic and endogenous PML-RARA in 293T and NB4 cells, respectively. In 293T cells, UBE2I-mediated PML-RARA degradation was reduced upon PCGF2 co-expression. In addition, UBE2I-mediated sumoylation of PML-RARA was reduced upon PCGF2 co-expression and PCGF2-UBE2I interaction was confirmed by co-immunoprecipitation. Likewise, endogenous PCGF2-UBE2I interaction was detected by co-immunoprecipitation and immunofluorescence assays in NB4 cells. Intriguingly, upon ATO-treatment, such interaction was disrupted and UBE2I was co-immunoprecipitated or co-localized with its SUMO substrate, PML-RARA. Taken together, our results suggested a novel role of PCGF2 in ATO-mediated degradation of PML-RARA that PCGF2 might act as a negative regulator of UBE2I via direct interaction. Copyright © 2016 Elsevier B.V. All rights reserved.

NUCLEAR PORE ANCHOR, the Arabidopsis Homolog of Tpr/Mlp1/Mlp2/Megator, Is Involved in mRNA Export and SUMO Homeostasis and Affects Diverse Aspects of Plant Development[W

PubMed Central

Xu, Xianfeng Morgan; Rose, Annkatrin; Muthuswamy, Sivaramakrishnan; Jeong, Sun Yong; Venkatakrishnan, Sowmya; Zhao, Qiao; Meier, Iris

2007-01-01

Vertebrate Tpr and its yeast homologs Mlp1/Mlp2, long coiled-coil proteins of nuclear pore inner basket filaments, are involved in mRNA export, telomere organization, spindle pole assembly, and unspliced RNA retention. We identified Arabidopsis thaliana NUCLEAR PORE ANCHOR (NUA) encoding a 237-kD protein with similarity to Tpr. NUA is located at the inner surface of the nuclear envelope in interphase and in the vicinity of the spindle in prometaphase. Four T-DNA insertion lines were characterized, which comprise an allelic series of increasing severity for several correlating phenotypes, such as early flowering under short days and long days, increased abundance of SUMO conjugates, altered expression of several flowering regulators, and nuclear accumulation of poly(A)+ RNA. nua mutants phenocopy mutants of EARLY IN SHORT DAYS4 (ESD4), an Arabidopsis SUMO protease concentrated at the nuclear periphery. nua esd4 double mutants resemble nua and esd4 single mutants, suggesting that the two proteins act in the same pathway or complex, supported by yeast two-hybrid interaction. Our data indicate that NUA is a component of nuclear pore-associated steps of sumoylation and mRNA export in plants and that defects in these processes affect the signaling events of flowering time regulation and additional developmental processes. PMID:17513499

HTLV-2B Tax oncoprotein is modified by ubiquitination and sumoylation and displays intracellular localization similar to its homologue HTLV-1 Tax

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turci, Marco; Lodewick, Julie; Righi, Paola

HTLV-1 is more pathogenic than HTLV-2B. The difference is generally attributed to the properties of their individual transactivating Tax proteins. By using internal Flag-6His tagged Tax-1 and Tax-2B, which display transcriptional activities comparable to the untagged proteins and can be recognized by a single anti-Flag antibody, we demonstrate that Tax-2B is modified by ubiquitination and sumoylation. In addition, Tax2B is distributed in punctuate nuclear structures that include the RelA subunit of NF-{kappa}B, as has been previously demonstrated for Tax-1.

Nuclear import of glucokinase in pancreatic beta-cells is mediated by a nuclear localization signal and modulated by SUMOylation.

PubMed

Johansson, Bente Berg; Fjeld, Karianne; Solheim, Marie Holm; Shirakawa, Jun; Zhang, Enming; Keindl, Magdalena; Hu, Jiang; Lindqvist, Andreas; Døskeland, Anne; Mellgren, Gunnar; Flatmark, Torgeir; Njølstad, Pål Rasmus; Kulkarni, Rohit N; Wierup, Nils; Aukrust, Ingvild; Bjørkhaug, Lise

2017-10-15

The localization of glucokinase in pancreatic beta-cell nuclei is a controversial issue. Although previous reports suggest such a localization, the mechanism for its import has so far not been identified. Using immunofluorescence, subcellular fractionation and mass spectrometry, we present evidence in support of glucokinase localization in beta-cell nuclei of human and mouse pancreatic sections, as well as in human and mouse isolated islets, and murine MIN6 cells. We have identified a conserved, seven-residue nuclear localization signal ( 30 LKKVMRR 36 ) in the human enzyme. Substituting the residues KK 31,32 and RR 35,36 with AA led to a loss of its nuclear localization in transfected cells. Furthermore, our data indicates that SUMOylation of glucokinase modulates its nuclear import, while high glucose concentrations do not significantly alter the enzyme nuclear/cytosolic ratio. Thus, for the first time, we provide data in support of a nuclear import of glucokinase mediated by a redundant mechanism, involving a nuclear localization signal, and which is modulated by its SUMOylation. These findings add new knowledge to the functional role of glucokinase in the pancreatic beta-cell. Copyright © 2017 Elsevier B.V. All rights reserved.

The SUMO Pathway in Mitosis.

PubMed

Mukhopadhyay, Debaditya; Dasso, Mary

2017-01-01

Mitosis is the stage of the cell cycle during which replicated chromosomes must be precisely divided to allow the formation of two daughter cells possessing equal genetic material. Much of the careful spatial and temporal organization of mitosis is maintained through post-translational modifications, such as phosphorylation and ubiquitination, of key cellular proteins. Here, we will review evidence that sumoylation, conjugation to the SUMO family of small ubiquitin-like modifiers, also serves essential regulatory roles during mitosis. We will discuss the basic biology of sumoylation, how the SUMO pathway has been implicated in particular mitotic functions, including chromosome condensation, centromere/kinetochore organization and cytokinesis, and what cellular proteins may be the targets underlying these phenomena.

Topoisomerase II Mediates Meiotic Crossover Interference

PubMed Central

Zhang, Liangran; Wang, Shunxin; Yin, Shen; Hong, Soogil; Kim, Keun P.; Kleckner, Nancy

2014-01-01

Summary Spatial patterning is a ubiquitous feature of biological systems. Meiotic crossovers provide an interesting example, defined by the classical phenomenon of crossover interference. Here, analysis of crossover patterns in budding yeast identifies a molecular pathway for interference. Topoisomerase II (Topo II) plays a central role, thus identifying a new function for this critical molecule. SUMOylation [of TopoII and axis component Red1] and ubiquitin-mediated removal of SUMOylated proteins are also required. These and other findings support the hypothesis that crossover interference involves accumulation, relief and redistribution of mechanical stress along the protein/DNA meshwork of meiotic chromosome axes, with TopoII required to adjust spatial relationships among DNA segments. PMID:25043020

A Fluorescent In Vitro Assay to Investigate Paralog-Specific SUMO Conjugation.

PubMed

Eisenhardt, Nathalie; Chaugule, Viduth K; Pichler, Andrea

2016-01-01

Protein modification with the small ubiquitin-related modifier SUMO is a potent regulatory mechanism implicated in a variety of biological pathways. In vitro sumoylation reactions have emerged as a versatile tool to identify and characterize novel SUMO enzymes as well as their substrates. Here, we present detailed protocols for the purification and fluorescent labeling of mammalian SUMO paralogs for their application in sumoylation assays. These assays provide a fast readout for in vitro SUMO chain formation activity of E3 ligases in a paralog-specific manner. Finally, we critically analyze the application of fluorescent SUMO proteins to study substrate modification in vitro revealing also the drawbacks of the system.

The role of adipose-derived inflammatory cytokines in type 1 diabetes

PubMed Central

Shao, Lan; Feng, Boya; Zhang, Yuying; Zhou, Huanjiao; Ji, Weidong; Min, Wang

2016-01-01

ABSTRACT Adipose tissue dysfunction correlates with the development of diabetes. Mice with an adipocyte-specific deletion of the SUMO-specific protease SENP1 develop symptoms of type-1 diabetes mellitus (T1DM). Peri-pancreatic adipocytes (PATs) exert both systemic and paracrine effects on pancreases function. Our recent studies report that PATs of SENP1-deficient mice have increased proinflammatory cytokine production compared with other adipose depots. Proinflammatory cytokines produced from PATs not only have direct cytotoxic effects on pancreatic islets, but also increase CCL5 expression in adjacent pancreatic islets, which induces persistent inflammation in pancreases by acquisition of Th1 and Th17 effector T cell subsets. Small ubiquitin-like modifier (SUMO) can post-translationally conjugate to cellular proteins (SUMOylation) and modulate their biological functions. Several components in SUMOylation associate with T1DM susceptibility. We find that SUMOylation of NF-κB essential molecule NEMO augments NF-κB activity, NF-κB-dependent cytokine production and pancreatic inflammation. NF-κB inhibitor should provide therapeutic approach to block PAT inflammation and ameliorate the T1DM phenotype. We further propose that adipocytes in PATs may play a primary role in establishing pancreatic immune regulation at onset of diabetes, providing new insights into the molecular pathogenesis of type 1 diabetes. PMID:27617172

Proteomics Analysis of Nucleolar SUMO-1 Target Proteins upon Proteasome Inhibition*

PubMed Central

Matafora, Vittoria; D'Amato, Alfonsina; Mori, Silvia; Blasi, Francesco; Bachi, Angela

2009-01-01

Many cellular processes are regulated by the coordination of several post-translational modifications that allow a very fine modulation of substrates. Recently it has been reported that there is a relationship between sumoylation and ubiquitination. Here we propose that the nucleolus is the key organelle in which SUMO-1 conjugates accumulate in response to proteasome inhibition. We demonstrated that, upon proteasome inhibition, the SUMO-1 nuclear dot localization is redirected to nucleolar structures. To better understand this process we investigated, by quantitative proteomics, the effect of proteasome activity on endogenous nucleolar SUMO-1 targets. 193 potential SUMO-1 substrates were identified, and interestingly in several purified SUMO-1 conjugates ubiquitin chains were found to be present, confirming the coordination of these two modifications. 23 SUMO-1 targets were confirmed by an in vitro sumoylation reaction performed on nuclear substrates. They belong to protein families such as small nuclear ribonucleoproteins, heterogeneous nuclear ribonucleoproteins, ribosomal proteins, histones, RNA-binding proteins, and transcription factor regulators. Among these, histone H1, histone H3, and p160 Myb-binding protein 1A were further characterized as novel SUMO-1 substrates. The analysis of the nature of the SUMO-1 targets identified in this study strongly indicates that sumoylation, acting in coordination with the ubiquitin-proteasome system, regulates the maintenance of nucleolar integrity. PMID:19596686

Trafficking and function of the cystic fibrosis transmembrane conductance regulator: a complex network of posttranslational modifications

PubMed Central

McClure, Michelle L.; Barnes, Stephen; Brodsky, Jeffrey L.

2016-01-01

Posttranslational modifications add diversity to protein function. Throughout its life cycle, the cystic fibrosis transmembrane conductance regulator (CFTR) undergoes numerous covalent posttranslational modifications (PTMs), including glycosylation, ubiquitination, sumoylation, phosphorylation, and palmitoylation. These modifications regulate key steps during protein biogenesis, such as protein folding, trafficking, stability, function, and association with protein partners and therefore may serve as targets for therapeutic manipulation. More generally, an improved understanding of molecular mechanisms that underlie CFTR PTMs may suggest novel treatment strategies for CF and perhaps other protein conformational diseases. This review provides a comprehensive summary of co- and posttranslational CFTR modifications and their significance with regard to protein biogenesis. PMID:27474090

Non-native Conformers of Cystic Fibrosis Transmembrane Conductance Regulator NBD1 Are Recognized by Hsp27 and Conjugated to SUMO-2 for Degradation.

PubMed

Gong, Xiaoyan; Ahner, Annette; Roldan, Ariel; Lukacs, Gergely L; Thibodeau, Patrick H; Frizzell, Raymond A

2016-01-22

A newly identified pathway for selective degradation of the common mutant of the cystic fibrosis transmembrane conductance regulator (CFTR), F508del, is initiated by binding of the small heat shock protein, Hsp27. Hsp27 collaborates with Ubc9, the E2 enzyme for protein SUMOylation, to selectively degrade F508del CFTR via the SUMO-targeted ubiquitin E3 ligase, RNF4 (RING finger protein 4) (1). Here, we ask what properties of CFTR are sensed by the Hsp27-Ubc9 pathway by examining the ability of NBD1 (locus of the F508del mutation) to mimic the disposal of full-length (FL) CFTR. Similar to FL CFTR, F508del NBD1 expression was reduced 50-60% by Hsp27; it interacted preferentially with the mutant and was modified primarily by SUMO-2. Mutation of the consensus SUMOylation site, Lys(447), obviated Hsp27-mediated F508del NBD1 SUMOylation and degradation. As for FL CFTR and NBD1 in vivo, SUMO modification using purified components in vitro was greater for F508del NBD1 versus WT and for the SUMO-2 paralog. Several findings indicated that Hsp27-Ubc9 targets the SUMOylation of a transitional, non-native conformation of F508del NBD1: (a) its modification decreased as [ATP] increased, reflecting stabilization of the nucleotide-binding domain by ligand binding; (b) a temperature-induced increase in intrinsic fluorescence, which reflects formation of a transitional NBD1 conformation, was followed by its SUMO modification; and (c) introduction of solubilizing or revertant mutations to stabilize F508del NBD1 reduced its SUMO modification. These findings indicate that the Hsp27-Ubc9 pathway recognizes a non-native conformation of mutant NBD1, which leads to its SUMO-2 conjugation and degradation by the ubiquitin-proteasome system. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Regulation of the mammalian heat shock factor 1.

PubMed

Dayalan Naidu, Sharadha; Dinkova-Kostova, Albena T

2017-06-01

Living organisms are endowed with the capability to tackle various forms of cellular stress due to the presence of molecular chaperone machinery complexes that are ubiquitous throughout the cell. During conditions of proteotoxic stress, the transcription factor heat shock factor 1 (HSF1) mediates the elevation of heat shock proteins, which are crucial components of the chaperone complex machinery and function to ameliorate protein misfolding and aggregation and restore protein homeostasis. In addition, HSF1 orchestrates a versatile transcriptional programme that includes genes involved in repair and clearance of damaged macromolecules and maintenance of cell structure and metabolism, and provides protection against a broad range of cellular stress mediators, beyond heat shock. Here, we discuss the structure and function of the mammalian HSF1 and its regulation by post-translational modifications (phosphorylation, sumoylation and acetylation), proteasomal degradation, and small-molecule activators and inhibitors. © 2017 Federation of European Biochemical Societies.

Investigating the Mechanisms Underlying Neuronal Death in Ischemia Using In Vitro Oxygen-Glucose Deprivation: Potential Involvement of Protein SUMOylation

PubMed Central

CIMAROSTI, HELENA; HENLEY, JEREMY M.

2012-01-01

It is well established that brain ischemia can cause neuronal death via different signaling cascades. The relative importance and interrelationships between these pathways, however, remain poorly understood. Here is presented an overview of studies using oxygen-glucose deprivation of organotypic hippocampal slice cultures to investigate the molecular mechanisms involved in ischemia. The culturing techniques, setup of the oxygen-glucose deprivation model, and analytical tools are reviewed. The authors focus on SUMOylation, a posttranslational protein modification that has recently been implicated in ischemia from whole animal studies as an example of how these powerful tools can be applied and could be of interest to investigate the molecular pathways underlying ischemic cell death. PMID:19029060

Generation and Nuclear Translocation of Sumoylated Transmembrane Fragment of Cell Adhesion Molecule L1

PubMed Central

Lutz, David; Wolters-Eisfeld, Gerrit; Joshi, Gunjan; Djogo, Nevena; Jakovcevski, Igor; Schachner, Melitta; Kleene, Ralf

2012-01-01

The functions of the cell adhesion molecule L1 in the developing and adult nervous system are triggered by homophilic and heterophilic interactions that stimulate signal transductions that activate cellular responses. Here, we show that stimulation of signaling by function-triggering L1 antibodies or L1-Fc leads to serine protease-dependent cleavage of full-length L1 at the plasma membrane and generation of a sumoylated transmembrane 70-kDa fragment comprising the intracellular and transmembrane domains and part of the extracellular domain. The 70-kDa transmembrane fragment is transported from the plasma membrane to a late endosomal compartment, released from endosomal membranes into the cytoplasm, and transferred from there into the nucleus by a pathway that depends on importin and chromatin-modifying protein 1. Mutation of the sumoylation site at Lys1172 or of the nuclear localization signal at Lys1147 abolished L1-stimulated generation or nuclear import of the 70-kDa fragment, respectively. Nuclear import of the 70-kDa fragment may activate cellular responses in parallel or in association with phosphorylation-dependent signaling pathways. Alterations in the levels of the 70-kDa fragment during development and in the adult after spinal cord injury or in a mouse model of Alzheimer disease suggest that this fragment is functionally implicated in development, regeneration, neurodegeneration, tumorigenesis, and possibly synaptic plasticity in the mature nervous system. PMID:22431726

Wrestling with Chromosomes: The Roles of SUMO During Meiosis.

PubMed

Nottke, Amanda C; Kim, Hyun-Min; Colaiácovo, Monica P

2017-01-01

Meiosis is a specialized form of cell division required for the formation of haploid gametes and therefore is essential for successful sexual reproduction. Various steps are exquisitely coordinated to ensure accurate chromosome segregation during meiosis, thereby promoting the formation of haploid gametes from diploid cells. Recent studies are demonstrating that an important form of regulation during meiosis is exerted by the post-translational protein modification known as sumoylation. Here, we review and discuss the various critical steps of meiosis in which SUMO-mediated regulation has been implicated thus far. These include the maintenance of meiotic centromeric heterochromatin , meiotic DNA double-strand break repair and homologous recombination, centromeric coupling, and the assembly of a proteinaceous scaffold between homologous chromosomes known as the synaptonemal complex.

RPA-coated single-stranded DNA as a platform for post-translational modifications in the DNA damage response

PubMed Central

Maréchal, Alexandre; Zou, Lee

2015-01-01

The Replication Protein A (RPA) complex is an essential regulator of eukaryotic DNA metabolism. RPA avidly binds to single-stranded DNA (ssDNA) through multiple oligonucleotide/oligosaccharide-binding folds and coordinates the recruitment and exchange of genome maintenance factors to regulate DNA replication, recombination and repair. The RPA-ssDNA platform also constitutes a key physiological signal which activates the master ATR kinase to protect and repair stalled or collapsed replication forks during replication stress. In recent years, the RPA complex has emerged as a key target and an important regulator of post-translational modifications in response to DNA damage, which is critical for its genome guardian functions. Phosphorylation and SUMOylation of the RPA complex, and more recently RPA-regulated ubiquitination, have all been shown to control specific aspects of DNA damage signaling and repair by modulating the interactions between RPA and its partners. Here, we review our current understanding of the critical functions of the RPA-ssDNA platform in the maintenance of genome stability and its regulation through an elaborate network of covalent modifications. PMID:25403473

RPA-coated single-stranded DNA as a platform for post-translational modifications in the DNA damage response.

PubMed

Maréchal, Alexandre; Zou, Lee

2015-01-01

The Replication Protein A (RPA) complex is an essential regulator of eukaryotic DNA metabolism. RPA avidly binds to single-stranded DNA (ssDNA) through multiple oligonucleotide/oligosaccharide-binding folds and coordinates the recruitment and exchange of genome maintenance factors to regulate DNA replication, recombination and repair. The RPA-ssDNA platform also constitutes a key physiological signal which activates the master ATR kinase to protect and repair stalled or collapsed replication forks during replication stress. In recent years, the RPA complex has emerged as a key target and an important regulator of post-translational modifications in response to DNA damage, which is critical for its genome guardian functions. Phosphorylation and SUMOylation of the RPA complex, and more recently RPA-regulated ubiquitination, have all been shown to control specific aspects of DNA damage signaling and repair by modulating the interactions between RPA and its partners. Here, we review our current understanding of the critical functions of the RPA-ssDNA platform in the maintenance of genome stability and its regulation through an elaborate network of covalent modifications.

Tax-1 and Tax-2 similarities and differences: focus on post-translational modifications and NF-κB activation

PubMed Central

Shirinian, Margret; Kfoury, Youmna; Dassouki, Zeina; El-Hajj, Hiba; Bazarbachi, Ali

2013-01-01

Although human T cell leukemia virus type 1 and 2 (HTLV-1 and HTLV-2) share similar genetic organization, they have major differences in their pathogenesis and disease manifestation. HTLV-1 is capable of transforming T lymphocytes in infected patients resulting in adult T cell leukemia/lymphoma whereas HTLV-2 is not clearly associated with lymphoproliferative diseases. Numerous studies have provided accumulating evidence on the involvement of the viral transactivators Tax-1 versus Tax-2 in T cell transformation. Tax-1 is a potent transcriptional activator of both viral and cellular genes. Tax-1 post-translational modifications and specifically ubiquitylation and SUMOylation have been implicated in nuclear factor-kappaB (NF-κB) activation and may contribute to its transformation capacity. Although Tax-2 has similar protein structure compared to Tax-1, the two proteins display differences both in their protein–protein interaction and activation of signal transduction pathways. Recent studies on Tax-2 have suggested ubiquitylation and SUMOylation independent mechanisms of NF-κB activation. In this present review, structural and functional differences between Tax-1 and Tax-2 will be summarized. Specifically, we will address their subcellular localization, nuclear trafficking and their effect on cellular regulatory proteins. A special attention will be given to Tax-1/Tax-2 post-translational modification such as ubiquitylation, SUMOylation, phosphorylation, acetylation, NF-κB activation, and protein–protein interactions involved in oncogenecity both in vivo and in vitro. PMID:23966989

The yeast SUMO isopeptidase Smt4/Ulp2 and the polo kinase Cdc5 act in an opposing fashion to regulate sumoylation in mitosis and cohesion at centromeres.

PubMed

Baldwin, Melissa L; Julius, Jeffrey A; Tang, Xianying; Wang, Yanchang; Bachant, Jeff

2009-10-15

Post-translation modification through the SUMO pathway is cell cycle regulated, with specific SUMO conjugates accumulating in mitotic cells. The basis for this regulation, however, and its functional significance remain poorly understood. We present evidence that in budding yeast sumoylation during mitosis may be controlled through the SUMO deconjugating enzyme Smt4/Ulp2. We isolated the polo kinase Cdc5 as an Ulp2-interacting protein, and find a C-terminal region of Ulp2 is phosphorylated during mitosis in a Cdc5-dependent manner. cdc5 mutants display reduced levels of mitotic SUMO conjugates, suggesting Cdc5 may negatively regulate Ulp2 to promote sumoylation. Previously, we found one phenotype associated with ulp2 mutants is an inability to maintain chromatid cohesion at centromere-proximal chromosomal regions. We now show this defect is rescued by inactivating Cdc5, indicating Ulp2 maintains cohesion by counter-acting Cdc5 activity. The cohesinregulator Pds5 is a likely target of this pathway, as Cdc5 overproduction forces Pds5 dissociation from chromosomes and Pds5 overproduction restores cohesion in ulp2 mutants. Overall, these observations reveal Cdc5 is a novel regulator of the SUMO pathway and suggest the outlines of a broader circuitry in which Ulp2 and Cdc5 act in a mutually antagonistic fashion to modulate maintenance and dissolution of cohesion at centromeres.

The transcription factor EGR1 localizes to the nucleolus and is linked to suppression of ribosomal precursor synthesis.

PubMed

Ponti, Donatella; Bellenchi, Gian Carlo; Puca, Rosa; Bastianelli, Daniela; Maroder, Marella; Ragona, Giuseppe; Roussel, Pascal; Thiry, Marc; Mercola, Dan; Calogero, Antonella

2014-01-01

EGR1 is an immediate early gene with a wide range of activities as transcription factor, spanning from regulation of cell growth to differentiation. Numerous studies show that EGR1 either promotes the proliferation of stimulated cells or suppresses the tumorigenic growth of transformed cells. Upon interaction with ARF, EGR1 is sumoylated and acquires the ability to bind to specific targets such as PTEN and in turn to regulate cell growth. ARF is mainly localized to the periphery of nucleolus where is able to negatively regulate ribosome biogenesis. Since EGR1 colocalizes with ARF under IGF-1 stimulation we asked the question of whether EGR1 also relocate to the nucleolus to interact with ARF. Here we show that EGR1 colocalizes with nucleolar markers such as fibrillarin and B23 in the presence of ARF. Western analysis of nucleolar extracts from HeLa cells was used to confirm the presence of EGR1 in the nucleolus mainly as the 100 kDa sumoylated form. We also show that the level of the ribosomal RNA precursor 47S is inversely correlated to the level of EGR1 transcripts. The EGR1 iseffective to regulate the synthesis of the 47S rRNA precursor. Then we demonstrated that EGR1 binds to the Upstream Binding Factor (UBF) leading us to hypothesize that the regulating activity of EGR1 is mediated by its interaction within the transcriptional complex of RNA polymerase I. These results confirm the presence of EGR1 in the nucleolus and point to a role for EGR1 in the control of nucleolar metabolism.

Trafficking of the transcription factor Nrf2 to promyelocytic leukemia-nuclear bodies: implications for degradation of NRF2 in the nucleus.

PubMed

Malloy, Melanie Theodore; McIntosh, Deneshia J; Walters, Treniqka S; Flores, Andrea; Goodwin, J Shawn; Arinze, Ifeanyi J

2013-05-17

Ubiquitylation of Nrf2 by the Keap1-Cullin3/RING box1 (Cul3-Rbx1) E3 ubiquitin ligase complex targets Nrf2 for proteasomal degradation in the cytoplasm and is an extensively studied mechanism for regulating the cellular level of Nrf2. Although mechanistic details are lacking, reports abound that Nrf2 can also be degraded in the nucleus. Here, we demonstrate that Nrf2 is a target for sumoylation by both SUMO-1 and SUMO-2. HepG2 cells treated with As2O3, which enhances attachment of SUMO-2/3 to target proteins, increased SUMO-2/3-modification (polysumoylation) of Nrf2. We show that Nrf2 traffics, in part, to promyelocytic leukemia-nuclear bodies (PML-NBs). Cell fractions harboring key components of PML-NBs did not contain biologically active Keap1 but contained modified Nrf2 as well as RING finger protein 4 (RNF4), a poly-SUMO-specific E3 ubiquitin ligase. Overexpression of wild-type RNF4, but not the catalytically inactive mutant, decreased the steady-state levels of Nrf2, measured in the PML-NB-enriched cell fraction. The proteasome inhibitor MG-132 interfered with this decrease, resulting in elevated levels of polysumoylated Nrf2 that was also ubiquitylated. Wild-type RNF4 accelerated the half-life (t½) of Nrf2, measured in PML-NB-enriched cell fractions. These results suggest that RNF4 mediates polyubiquitylation of polysumoylated Nrf2, leading to its subsequent degradation in PML-NBs. Overall, this work identifies Nrf2 as a target for sumoylation and provides a novel mechanism for its degradation in the nucleus, independent of Keap1.

Functional characterization of DnSIZ1, a SIZ/PIAS-type SUMO E3 ligase from Dendrobium.

PubMed

Liu, Feng; Wang, Xiao; Su, Mengying; Yu, Mengyuan; Zhang, Shengchun; Lai, Jianbin; Yang, Chengwei; Wang, Yaqin

2015-09-17

SUMOylation is an important post-translational modification of eukaryotic proteins that involves the reversible conjugation of a small ubiquitin-related modifier (SUMO) polypeptide to its specific protein substrates, thereby regulating numerous complex cellular processes. The PIAS (protein inhibitor of activated signal transducers and activators of transcription [STAT]) and SIZ (scaffold attachment factor A/B/acinus/PIAS [SAP] and MIZ) proteins are SUMO E3 ligases that modulate SUMO conjugation. The characteristic features and SUMOylation mechanisms of SIZ1 protein in monocotyledon are poorly understood. Here, we examined the functions of a homolog of Arabidopsis SIZ1, a functional SIZ/PIAS-type SUMO E3 ligase from Dendrobium. In Dendrobium, the predicted DnSIZ1 protein has domains that are highly conserved among SIZ/PIAS-type proteins. DnSIZ1 is widely expressed in Dendrobium organs and has a up-regulated trend by treatment with cold, high temperature and wounding. The DnSIZ1 protein localizes to the nucleus and shows SUMO E3 ligase activity when expressed in an Escherichia coli reconstitution system. Moreover, ectopic expression of DnSIZ1 in the Arabidopsis siz1-2 mutant partially complements several phenotypes and results in enhanced levels of SUMO conjugates in plants exposed to heat shock conditions. We observed that DnSIZ1 acts as a negative regulator of flowering transition which may be via a vernalization-induced pathway. In addition, ABA-hypersensitivity of siz1-2 seed germination can be partially suppressed by DnSIZ1. Our results suggest that DnSIZ1 is a functional homolog of the Arabidopsis SIZ1 with SUMO E3 ligase activity and may play an important role in the regulation of Dendrobium stress responses, flowering and development.

USP7 is a SUMO deubiquitinase essential for DNA replication.

PubMed

Lecona, Emilio; Rodriguez-Acebes, Sara; Specks, Julia; Lopez-Contreras, Andres J; Ruppen, Isabel; Murga, Matilde; Muñoz, Javier; Mendez, Juan; Fernandez-Capetillo, Oscar

2016-04-01

Post-translational modification of proteins by ubiquitin (Ub) and Ub-like modifiers regulates DNA replication. We have previously shown that chromatin around replisomes is rich in SUMO and poor in Ub, whereas mature chromatin exhibits an opposite pattern. How this SUMO-rich, Ub-poor environment is maintained at sites of DNA replication in mammalian cells remains unexplored. Here we identify USP7 as a replisome-enriched SUMO deubiquitinase that is essential for DNA replication. By acting on SUMO and SUMOylated proteins, USP7 counteracts their ubiquitination. Inhibition or genetic deletion of USP7 leads to the accumulation of Ub on SUMOylated proteins, which are displaced away from replisomes. Our findings provide a model explaining the differential accumulation of SUMO and Ub at replication forks and identify an essential role of USP7 in DNA replication that should be considered in the development of USP7 inhibitors as anticancer agents.

The SUMO Pathway Promotes Basic Helix-Loop-Helix Proneural Factor Activity via a Direct Effect on the Zn Finger Protein Senseless

PubMed Central

Chen, Angela; Huang, Yan Chang; Wang, Pin Yao; Kemp, Sadie E.

2012-01-01

During development, proneural transcription factors of the basic helix-loop-helix (bHLH) family are required to commit cells to a neural fate. In Drosophila neurogenesis, a key mechanism promoting sense organ precursor (SOP) fate is the synergy between proneural factors and their coactivator Senseless in transcriptional activation of target genes. Here we present evidence that posttranslational modification by SUMO enhances this synergy via an effect on Senseless protein. We show that Senseless is a direct target for SUMO modification and that mutagenesis of a predicted SUMOylation motif in Senseless reduces Senseless/proneural synergy both in vivo and in cell culture. We propose that SUMOylation of Senseless via lysine 509 promotes its synergy with proneural proteins during transcriptional activation and hence regulates an important step in neurogenesis leading to the formation and maturation of the SOPs. PMID:22586269

Genetic incorporation of Nε-acetyllysine reveals a novel acetylation-sumoylation switch in yeast.

PubMed

Kim, Sang-Woo; Lee, Kyung Jin; Kim, Sinil; Kim, Jihyo; Cho, Kyukwang; Ro, Hyeon-Su; Park, Hee-Sung

2017-11-01

The lysine acetylation of proteins plays a key role in regulating protein functions, thereby controlling a wide range of cellular processes. Despite the prevalence and significance of lysine acetylation in eukaryotes, however, its systematic study has been challenged by the technical limitations of conventional approaches for selective lysine acetylation in vivo. Here, we report the in vivo study of lysine acetylation via the genetic incorporation of N ε -acetyllysine in yeast. We demonstrate that a newly discovered acetylation-sumoylation switch precisely controls the localization and cellular function of the yeast septin protein, Cdc11, during the cell cycle. This approach should facilitate the comprehensive in vivo study of lysine acetylation across a wide range of proteins in eukaryotic organisms. This article is part of a Special Issue entitled "Biochemistry of Synthetic Biology - Recent Developments" Guest Editor: Dr. Ilka Heinemann and Dr. Patrick O'Donoghue. Copyright © 2017 Elsevier B.V. All rights reserved.

pSumo-CD: predicting sumoylation sites in proteins with covariance discriminant algorithm by incorporating sequence-coupled effects into general PseAAC.

PubMed

Jia, Jianhua; Zhang, Liuxia; Liu, Zi; Xiao, Xuan; Chou, Kuo-Chen

2016-10-15

Sumoylation is a post-translational modification (PTM) process, in which small ubiquitin-related modifier (SUMO) is attaching by covalent bonds to substrate protein. It is critical to many different biological processes such as replicating genome, expressing gene, localizing and stabilizing proteins; unfortunately, it is also involved with many major disorders including Alzheimer's and Parkinson's diseases. Therefore, for both basic research and drug development, it is important to identify the sumoylation sites in proteins. To address such a problem, we developed a predictor called pSumo-CD by incorporating the sequence-coupled information into the general pseudo-amino acid composition (PseAAC) and introducing the covariance discriminant (CD) algorithm, in which a bias-adjustment term, which has the function to automatically adjust the errors caused by the bias due to the imbalance of training data, had been incorporated. Rigorous cross-validations indicated that the new predictor remarkably outperformed the existing state-of-the-art prediction method for the same purpose. For the convenience of most experimental scientists, a user-friendly web-server for pSumo-CD has been established at http://www.jci-bioinfo.cn/pSumo-CD, by which users can easily obtain their desired results without the need to go through the complicated mathematical equations involved. jjia@gordonlifescience.org, xxiao@gordonlifescience.org or kcchou@gordonlifescience.orgSupplementary information: Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

SUMOylation is developmentally regulated and required for cell pairing during conjugation in Tetrahymena thermophila.

PubMed

Nasir, Amjad M; Yang, Qianyi; Chalker, Douglas L; Forney, James D

2015-02-01

The covalent attachment of small ubiquitin-like modifier (SUMO) to target proteins regulates numerous nuclear events in eukaryotes, including transcription, mitosis and meiosis, and DNA repair. Despite extensive interest in nuclear pathways within the field of ciliate molecular biology, there have been no investigations of the SUMO pathway in Tetrahymena. The developmental program of sexual reproduction of this organism includes cell pairing, micronuclear meiosis, and the formation of a new somatic macronucleus. We identified the Tetrahymena thermophila SMT3 (SUMO) and UBA2 (SUMO-activating enzyme) genes and demonstrated that the corresponding green fluorescent protein (GFP) tagged gene products are found predominantly in the somatic macronucleus during vegetative growth. Use of an anti-Smt3p antibody to perform immunoblot assays with whole-cell lysates during conjugation revealed a large increase in SUMOylation that peaked during formation of the new macronucleus. Immunofluorescence using the same antibody showed that the increase was localized primarily within the new macronucleus. To initiate functional analysis of the SUMO pathway, we created germ line knockout cell lines for both the SMT3 and UBA2 genes and found both are essential for cell viability. Conditional Smt3p and Uba2p cell lines were constructed by incorporation of the cadmium-inducible metallothionein promoter. Withdrawal of cadmium resulted in reduced cell growth and increased sensitivity to DNA-damaging agents. Interestingly, Smt3p and Uba2p conditional cell lines were unable to pair during sexual reproduction in the absence of cadmium, consistent with a function early in conjugation. Our studies are consistent with multiple roles for SUMOylation in Tetrahymena, including a dynamic regulation associated with the sexual life cycle. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Small heat shock proteins target mutant cystic fibrosis transmembrane conductance regulator for degradation via a small ubiquitin-like modifier–dependent pathway

PubMed Central

Ahner, Annette; Gong, Xiaoyan; Schmidt, Bela Z.; Peters, Kathryn W.; Rabeh, Wael M.; Thibodeau, Patrick H.; Lukacs, Gergely L.; Frizzell, Raymond A.

2013-01-01

Small heat shock proteins (sHsps) bind destabilized proteins during cell stress and disease, but their physiological functions are less clear. We evaluated the impact of Hsp27, an sHsp expressed in airway epithelial cells, on the common protein misfolding mutant that is responsible for most cystic fibrosis. F508del cystic fibrosis transmembrane conductance regulator (CFTR), a well-studied protein that is subject to cytosolic quality control, selectively associated with Hsp27, whose overexpression preferentially targeted mutant CFTR to proteasomal degradation. Hsp27 interacted physically with Ubc9, the small ubiquitin-like modifier (SUMO) E2 conjugating enzyme, implying that F508del SUMOylation leads to its sHsp-mediated degradation. Enhancing or disabling the SUMO pathway increased or blocked Hsp27’s ability to degrade mutant CFTR. Hsp27 promoted selective SUMOylation of F508del NBD1 in vitro and of full-length F508del CFTR in vivo, which preferred endogenous SUMO-2/3 paralogues that form poly-chains. The SUMO-targeted ubiquitin ligase (STUbL) RNF4 recognizes poly-SUMO chains to facilitate nuclear protein degradation. RNF4 overexpression elicited F508del degradation, whereas Hsp27 knockdown blocked RNF4’s impact on mutant CFTR. Similarly, the ability of Hsp27 to degrade F508del CFTR was lost during overexpression of dominant-negative RNF4. These findings link sHsp-mediated F508del CFTR degradation to its SUMOylation and to STUbL-mediated targeting to the ubiquitin–proteasome system and thereby implicate this pathway in the disposal of an integral membrane protein. PMID:23155000

SUMOylation of HSP27 by small ubiquitin-like modifier 2/3 promotes proliferation and invasion of hepatocellular carcinoma cells.

PubMed

Ge, Haize; Du, Juan; Xu, Jingman; Meng, Xiangliang; Tian, Jinchuan; Yang, Jie; Liang, Huimin

2017-08-03

Primary hepatocellular carcinoma (PHC) is a major health problem worldwide and is one of the 10 most commonly diagnosed cancers in China. Heat shock protein 27 (HSP27) were found to be overexpressed in a wide range of malignancies including PHC, however, post-translational modification of HSP27 still needs exploration in PHC. Recently, SUMOylation, an important post-translational modification associating with the development of many kinds of cancers has been intensively studied. In the current study, mRNA and protein level of HSP27 in archived tumor samples representing various pathological characteristics of PHC were examined, and modification of HSP27 by SUMO2/3 was investigated. HSP27 were expressed abundantly in patients' tumor tissues, and found to be associated with pathological progression. Besides, HSP27 was also elevated significantly in liver cancer cell lines Huh7 and HepG2 compared with human hepatocyte cells L02. Furthermore, knockdown of HSP27 was found to be associated with the decreased proliferation and invasion ability in Huh7 and HepG2 cells. Immunofluorescence assay showed that HSP27 and SUMO2/3 were co-localized in the subcellular, and co-immunoprecipitation verified the interaction between HSP27 and SUMO2/3. Overexpression of SUMO2/3 upregulated the HSP27 protein level and promotes Huh7 and HepG2 cell proliferation and invasion, and vice versa when the SUMO2/3 was knockdown. Taken together, increased protein level of HSP27 through SUMO2/3-mediated SUMOylation plays crucial roles in the progression of PHC, and this finding may shed light on developing potential therapeutic targets for PHC.

A Novel Post-translational Modification of Nucleolin, SUMOylation at Lys-294, Mediates Arsenite-induced Cell Death by Regulating gadd45α mRNA Stability*

PubMed Central

Zhang, Dongyun; Liang, Yuguang; Xie, Qipeng; Gao, Guangxun; Wei, Jinlong; Huang, Haishan; Li, Jingxia; Gao, Jimin; Huang, Chuanshu

2015-01-01

Nucleolin is a ubiquitously expressed protein and participates in many important biological processes, such as cell cycle regulation and ribosomal biogenesis. The activity of nucleolin is regulated by intracellular localization and post-translational modifications, including phosphorylation, methylation, and ADP-ribosylation. Small ubiquitin-like modifier (SUMO) is a category of recently verified forms of post-translational modifications and exerts various effects on the target proteins. In the studies reported here, we discovered SUMOylational modification of human nucleolin protein at Lys-294, which facilitated the mRNA binding property of nucleolin by maintaining its nuclear localization. In response to arsenic exposure, nucleolin-SUMO was induced and promoted its binding with gadd45α mRNA, which increased gadd45α mRNA stability and protein expression, subsequently causing GADD45α-mediated cell death. On the other hand, ectopic expression of Mn-SOD attenuated the arsenite-generated superoxide radical level, abrogated nucleolin-SUMO, and in turn inhibited arsenite-induced apoptosis by reducing GADD45α expression. Collectively, our results for the first time demonstrate that nucleolin-SUMO at K294R plays a critical role in its nucleus sequestration and gadd45α mRNA binding activity. This novel biological function of nucleolin is distinct from its conventional role as a proto-oncogene. Therefore, our findings here not only reveal a new modification of nucleolin protein and its novel functional paradigm in mRNA metabolism but also expand our understanding of the dichotomous roles of nucleolin in terms of cancer development, which are dependent on multiple intracellular conditions and consequently the appropriate regulations of its modifications, including SUMOylation. PMID:25561743

Regulation of the Tumor-Suppressor Function of the Class III Phosphatidylinositol 3-Kinase Complex by Ubiquitin and SUMO.

PubMed

Reidick, Christina; El Magraoui, Fouzi; Meyer, Helmut E; Stenmark, Harald; Platta, Harald W

2014-12-23

The occurrence of cancer is often associated with a dysfunction in one of the three central membrane-involution processes-autophagy, endocytosis or cytokinesis. Interestingly, all three pathways are controlled by the same central signaling module: the class III phosphatidylinositol 3-kinase (PI3K-III) complex and its catalytic product, the phosphorylated lipid phosphatidylinositol 3-phosphate (PtdIns3P). The activity of the catalytic subunit of the PI3K-III complex, the lipid-kinase VPS34, requires the presence of the membrane-targeting factor VPS15 as well as the adaptor protein Beclin 1. Furthermore, a growing list of regulatory proteins associates with VPS34 via Beclin 1. These accessory factors define distinct subunit compositions and thereby guide the PI3K-III complex to its different cellular and physiological roles. Here we discuss the regulation of the PI3K-III complex components by ubiquitination and SUMOylation. Especially Beclin 1 has emerged as a highly regulated protein, which can be modified with Lys11-, Lys48- or Lys63-linked polyubiquitin chains catalyzed by distinct E3 ligases from the RING-, HECT-, RBR- or Cullin-type. We also point out other cross-links of these ligases with autophagy in order to discuss how these data might be merged into a general concept.

E3 ligase Hei10: a multifaceted structure-based signaling molecule with roles within and beyond meiosis

PubMed Central

De Muyt, Arnaud; Zhang, Liangran; Piolot, Tristan; Kleckner, Nancy; Espagne, Eric; Zickler, Denise

2014-01-01

Human enhancer of invasion-10 (Hei10) mediates meiotic recombination and also plays roles in cell proliferation. Here we explore Hei10’s roles throughout the sexual cycle of the fungus Sordaria with respect to localization and effects of null, RING-binding, and putative cyclin-binding (RXL) domain mutations. Hei10 makes three successive types of foci. Early foci form along synaptonemal complex (SC) central regions. At some of these positions, depending on its RING and RXL domains, Hei10 mediates development and turnover of two sequential types of recombination complexes, each demarked by characteristic amplified Hei10 foci. Integration with ultrastructural data for recombination nodules further reveals that recombination complexes differentiate into three types, one of which corresponds to crossover recombination events during or prior to SC formation. Finally, Hei10 positively and negatively modulates SUMO localization along SCs by its RING and RXL domains, respectively. The presented findings suggest that Hei10 integrates signals from the SC, associated recombination complexes, and the cell cycle to mediate both the development and programmed turnover/evolution of recombination complexes via SUMOylation/ubiquitination. Analogous cell cycle-linked assembly/disassembly switching could underlie localization and roles for Hei10 in centrosome/spindle pole body dynamics and associated nuclear trafficking. We suggest that Hei10 is a unique type of structure-based signal transduction protein. PMID:24831702

Regulation of the Tumor-Suppressor Function of the Class III Phosphatidylinositol 3-Kinase Complex by Ubiquitin and SUMO

PubMed Central

Reidick, Christina; El Magraoui, Fouzi; Meyer, Helmut E.; Stenmark, Harald; Platta, Harald W.

2014-01-01

The occurrence of cancer is often associated with a dysfunction in one of the three central membrane-involution processes—autophagy, endocytosis or cytokinesis. Interestingly, all three pathways are controlled by the same central signaling module: the class III phosphatidylinositol 3-kinase (PI3K-III) complex and its catalytic product, the phosphorylated lipid phosphatidylinositol 3-phosphate (PtdIns3P). The activity of the catalytic subunit of the PI3K-III complex, the lipid-kinase VPS34, requires the presence of the membrane-targeting factor VPS15 as well as the adaptor protein Beclin 1. Furthermore, a growing list of regulatory proteins associates with VPS34 via Beclin 1. These accessory factors define distinct subunit compositions and thereby guide the PI3K-III complex to its different cellular and physiological roles. Here we discuss the regulation of the PI3K-III complex components by ubiquitination and SUMOylation. Especially Beclin 1 has emerged as a highly regulated protein, which can be modified with Lys11-, Lys48- or Lys63-linked polyubiquitin chains catalyzed by distinct E3 ligases from the RING-, HECT-, RBR- or Cullin-type. We also point out other cross-links of these ligases with autophagy in order to discuss how these data might be merged into a general concept. PMID:25545884

SUMO chain formation relies on the amino-terminal region of SUMO-conjugating enzyme and has dedicated substrates in plants

PubMed Central

Tomanov, Konstantin; Nehlin, Lilian; Ziba, Ionida

2018-01-01

The small ubiquitin-related modifier (SUMO) conjugation apparatus usually attaches single SUMO moieties to its substrates, but SUMO chains have also been identified. To better define the biochemical requirements and characteristics of SUMO chain formation, mutations in surface-exposed Lys residues of Arabidopsis SUMO-conjugating enzyme (SCE) were tested for in vitro activity. Lys-to-Arg changes in the amino-terminal region of SCE allowed SUMO acceptance from SUMO-activating enzyme and supported substrate mono-sumoylation, but these mutations had significant effects on SUMO chain assembly. We found no indication that SUMO modification of SCE promotes chain formation. A substrate was identified that is modified by SUMO chain addition, showing that SCE can distinguish substrates for either mono-sumoylation or SUMO chain attachment. It is also shown that SCE with active site Cys mutated to Ser can accept SUMO to form an oxyester, but cannot transfer this SUMO moiety onto substrates, explaining a previously known dominant negative effect of this mutation. PMID:29133528

USP7/HAUSP: A SUMO deubiquitinase at the heart of DNA replication.

PubMed

Smits, Veronique A J; Freire, Raimundo

2016-09-01

DNA replication is both highly conserved and controlled. Problematic DNA replication can lead to genomic instability and therefore carcinogenesis. Numerous mechanisms work together to achieve this tight control and increasing evidence suggests that post-translational modifications (phosphorylation, ubiquitination, SUMOylation) of DNA replication proteins play a pivotal role in this process. Here we discuss such modifications in the light of a recent article that describes a novel role for the deubiquitinase (DUB) USP7/HAUSP in the control of DNA replication. USP7 achieves this function by an unusual and novel mechanism, namely deubiquitination of SUMOylated proteins at the replication fork, making USP7 also a SUMO DUB (SDUB). This work extends previous observations of increased levels of SUMO and low levels of ubiquitin at the on-going replication fork. Here, we discuss this novel study, its contribution to the DNA replication and genomic stability field and what questions arise from this work. © 2016 WILEY Periodicals, Inc.

USP7 is a SUMO deubiquitinase essential for DNA replication

PubMed Central

Lecona, Emilio; Rodriguez-Acebes, Sara; Specks, Julia; Lopez-Contreras, Andres J; Ruppen, Isabel; Murga, Matilde; Muñoz, Javier; Mendez, Juan; Fernandez-Capetillo, Oscar

2016-01-01

Post-translational modification of proteins by ubiquitin (Ub) and Ub-like modifiers regulates various aspects of DNA replication. We previously showed that the chromatin around replisomes is rich in SUMO and depleted in Ub, whereas an opposite pattern is observed in mature chromatin. How this SUMO-rich/Ub-low environment is maintained at sites of DNA replication is not known. Here we identify USP7 as a replisome-enriched SUMO deubiquitinase that is essential for DNA replication. By acting on SUMO and SUMOylated proteins, USP7 counteracts their ubiquitination. Chemical inhibition or genetic deletion of USP7 leads to the accumulation of Ub on SUMOylated proteins, which are displaced to chromatin away from replisomes. Our findings provide a model to explain the differential accumulation of SUMO and Ub at replication forks, and identify an essential role of USP7 in DNA replication that should be taken into account for the use of USP7 inhibitors as anticancer agents. PMID:26950370

Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control.

PubMed

Gallina, Irene; Colding, Camilla; Henriksen, Peter; Beli, Petra; Nakamura, Kyosuke; Offman, Judith; Mathiasen, David P; Silva, Sonia; Hoffmann, Eva; Groth, Anja; Choudhary, Chunaram; Lisby, Michael

2015-03-30

DNA replication stress is a source of genomic instability. Here we identify changed mutation rate 1 (Cmr1) as a factor involved in the response to DNA replication stress in Saccharomyces cerevisiae and show that Cmr1--together with Mrc1/Claspin, Pph3, the chaperonin containing TCP1 (CCT) and 25 other proteins--define a novel intranuclear quality control compartment (INQ) that sequesters misfolded, ubiquitylated and sumoylated proteins in response to genotoxic stress. The diversity of proteins that localize to INQ indicates that other biological processes such as cell cycle progression, chromatin and mitotic spindle organization may also be regulated through INQ. Similar to Cmr1, its human orthologue WDR76 responds to proteasome inhibition and DNA damage by relocalizing to nuclear foci and physically associating with CCT, suggesting an evolutionarily conserved biological function. We propose that Cmr1/WDR76 plays a role in the recovery from genotoxic stress through regulation of the turnover of sumoylated and phosphorylated proteins.

SUMO5, a Novel Poly-SUMO Isoform, Regulates PML Nuclear Bodies

PubMed Central

Liang, Ya-Chen; Lee, Chia-Chin; Yao, Ya-Li; Lai, Chien-Chen; Schmitz, M. Lienhard; Yang, Wen-Ming

2016-01-01

Promyelocytic leukemia nuclear bodies (PML-NBs) are PML-based nuclear structures that regulate various cellular processes. SUMOylation, the process of covalently conjugating small ubiquitin-like modifiers (SUMOs), is required for both the formation and the disruption of PML-NBs. However, detailed mechanisms of how SUMOylation regulates these processes remain unknown. Here we report that SUMO5, a novel SUMO variant, mediates the growth and disruption of PML-NBs. PolySUMO5 conjugation of PML at lysine 160 facilitates recruitment of PML-NB components, which enlarges PML-NBs. SUMO5 also increases polySUMO2/3 conjugation of PML, resulting in RNF4-mediated disruption of PML-NBs. The acute promyelocytic leukemia oncoprotein PML-RARα blocks SUMO5 conjugation of PML, causing cytoplasmic displacement of PML and disruption of PML-NBs. Our work not only identifies a new member of the SUMO family but also reveals the mechanistic basis of the PML-NB life cycle in human cells. PMID:27211601

Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control

PubMed Central

Gallina, Irene; Colding, Camilla; Henriksen, Peter; Beli, Petra; Nakamura, Kyosuke; Offman, Judith; Mathiasen, David P.; Silva, Sonia; Hoffmann, Eva; Groth, Anja; Choudhary, Chunaram; Lisby, Michael

2015-01-01

DNA replication stress is a source of genomic instability. Here we identify changed mutation rate 1 (Cmr1) as a factor involved in the response to DNA replication stress in Saccharomyces cerevisiae and show that Cmr1—together with Mrc1/Claspin, Pph3, the chaperonin containing TCP1 (CCT) and 25 other proteins—define a novel intranuclear quality control compartment (INQ) that sequesters misfolded, ubiquitylated and sumoylated proteins in response to genotoxic stress. The diversity of proteins that localize to INQ indicates that other biological processes such as cell cycle progression, chromatin and mitotic spindle organization may also be regulated through INQ. Similar to Cmr1, its human orthologue WDR76 responds to proteasome inhibition and DNA damage by relocalizing to nuclear foci and physically associating with CCT, suggesting an evolutionarily conserved biological function. We propose that Cmr1/WDR76 plays a role in the recovery from genotoxic stress through regulation of the turnover of sumoylated and phosphorylated proteins. PMID:25817432

The AAA-ATPase molecular chaperone Cdc48/p97 disassembles sumoylated centromeres, decondenses heterochromatin, and activates ribosomal RNA genes.

PubMed

Mérai, Zsuzsanna; Chumak, Nina; García-Aguilar, Marcelina; Hsieh, Tzung-Fu; Nishimura, Toshiro; Schoft, Vera K; Bindics, János; Slusarz, Lucyna; Arnoux, Stéphanie; Opravil, Susanne; Mechtler, Karl; Zilberman, Daniel; Fischer, Robert L; Tamaru, Hisashi

2014-11-11

Centromeres mediate chromosome segregation and are defined by the centromere-specific histone H3 variant (CenH3)/centromere protein A (CENP-A). Removal of CenH3 from centromeres is a general property of terminally differentiated cells, and the persistence of CenH3 increases the risk of diseases such as cancer. However, active mechanisms of centromere disassembly are unknown. Nondividing Arabidopsis pollen vegetative cells, which transport engulfed sperm by extended tip growth, undergo loss of CenH3; centromeric heterochromatin decondensation; and bulk activation of silent rRNA genes, accompanied by their translocation into the nucleolus. Here, we show that these processes are blocked by mutations in the evolutionarily conserved AAA-ATPase molecular chaperone, CDC48A, homologous to yeast Cdc48 and human p97 proteins, both of which are implicated in ubiquitin/small ubiquitin-like modifier (SUMO)-targeted protein degradation. We demonstrate that CDC48A physically associates with its heterodimeric cofactor UFD1-NPL4, known to bind ubiquitin and SUMO, as well as with SUMO1-modified CenH3 and mutations in NPL4 phenocopy cdc48a mutations. In WT vegetative cell nuclei, genetically unlinked ribosomal DNA (rDNA) loci are uniquely clustered together within the nucleolus and all major rRNA gene variants, including those rDNA variants silenced in leaves, are transcribed. In cdc48a mutant vegetative cell nuclei, however, these rDNA loci frequently colocalized with condensed centromeric heterochromatin at the external periphery of the nucleolus. Our results indicate that the CDC48A(NPL4) complex actively removes sumoylated CenH3 from centromeres and disrupts centromeric heterochromatin to release bulk rRNA genes into the nucleolus for ribosome production, which fuels single nucleus-driven pollen tube growth and is essential for plant reproduction.

The AAA-ATPase molecular chaperone Cdc48/p97 disassembles sumoylated centromeres, decondenses heterochromatin, and activates ribosomal RNA genes

PubMed Central

Mérai, Zsuzsanna; Chumak, Nina; García-Aguilar, Marcelina; Hsieh, Tzung-Fu; Nishimura, Toshiro; Schoft, Vera K.; Bindics, János; Ślusarz, Lucyna; Arnoux, Stéphanie; Opravil, Susanne; Mechtler, Karl; Zilberman, Daniel; Fischer, Robert L.; Tamaru, Hisashi

2014-01-01

Centromeres mediate chromosome segregation and are defined by the centromere-specific histone H3 variant (CenH3)/centromere protein A (CENP-A). Removal of CenH3 from centromeres is a general property of terminally differentiated cells, and the persistence of CenH3 increases the risk of diseases such as cancer. However, active mechanisms of centromere disassembly are unknown. Nondividing Arabidopsis pollen vegetative cells, which transport engulfed sperm by extended tip growth, undergo loss of CenH3; centromeric heterochromatin decondensation; and bulk activation of silent rRNA genes, accompanied by their translocation into the nucleolus. Here, we show that these processes are blocked by mutations in the evolutionarily conserved AAA-ATPase molecular chaperone, CDC48A, homologous to yeast Cdc48 and human p97 proteins, both of which are implicated in ubiquitin/small ubiquitin-like modifier (SUMO)-targeted protein degradation. We demonstrate that CDC48A physically associates with its heterodimeric cofactor UFD1-NPL4, known to bind ubiquitin and SUMO, as well as with SUMO1-modified CenH3 and mutations in NPL4 phenocopy cdc48a mutations. In WT vegetative cell nuclei, genetically unlinked ribosomal DNA (rDNA) loci are uniquely clustered together within the nucleolus and all major rRNA gene variants, including those rDNA variants silenced in leaves, are transcribed. In cdc48a mutant vegetative cell nuclei, however, these rDNA loci frequently colocalized with condensed centromeric heterochromatin at the external periphery of the nucleolus. Our results indicate that the CDC48ANPL4 complex actively removes sumoylated CenH3 from centromeres and disrupts centromeric heterochromatin to release bulk rRNA genes into the nucleolus for ribosome production, which fuels single nucleus-driven pollen tube growth and is essential for plant reproduction. PMID:25344531

Acetylation of the human T-cell leukemia virus type 1 Tax oncoprotein by p300 promotes activation of the NF-{kappa}B pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lodewick, Julie; Lamsoul, Isabelle; Polania, Angela

The oncogenic potential of the HTLV-1 Tax protein involves activation of the NF-{kappa}B pathway, which depends on Tax phosphorylation, ubiquitination and sumoylation. We demonstrate that the nuclei of Tax-expressing cells, including HTLV-1 transformed T-lymphocytes, contain a pool of Tax molecules acetylated on lysine residue at amino acid position 346 by the transcriptional coactivator p300. Phosphorylation of Tax on serine residues 300/301 was a prerequisite for Tax localization in the nucleus and correlated with its subsequent acetylation by p300, whereas sumoylation, resulting in the formation of Tax nuclear bodies in which p300 was recruited, favored Tax acetylation. Overexpression of p300 markedlymore » increased Tax acetylation and the ability of a wild type HTLV-1 provirus, -but not of a mutant provirus carrying an acetylation deficient Tax gene-, to activate gene expression from an integrated NF-{kappa}B-controlled promoter. Thus, Tax acetylation favors NF-{kappa}B activation and might play an important role in HTLV-1-induced cell transformation.« less

Arsenic trioxide controls the fate of the PML-RARalpha oncoprotein by directly binding PML.

PubMed

Zhang, Xiao-Wei; Yan, Xiao-Jing; Zhou, Zi-Ren; Yang, Fei-Fei; Wu, Zi-Yu; Sun, Hong-Bin; Liang, Wen-Xue; Song, Ai-Xin; Lallemand-Breitenbach, Valérie; Jeanne, Marion; Zhang, Qun-Ye; Yang, Huai-Yu; Huang, Qiu-Hua; Zhou, Guang-Biao; Tong, Jian-Hua; Zhang, Yan; Wu, Ji-Hui; Hu, Hong-Yu; de Thé, Hugues; Chen, Sai-Juan; Chen, Zhu

2010-04-09

Arsenic, an ancient drug used in traditional Chinese medicine, has attracted worldwide interest because it shows substantial anticancer activity in patients with acute promyelocytic leukemia (APL). Arsenic trioxide (As2O3) exerts its therapeutic effect by promoting degradation of an oncogenic protein that drives the growth of APL cells, PML-RARalpha (a fusion protein containing sequences from the PML zinc finger protein and retinoic acid receptor alpha). PML and PML-RARalpha degradation is triggered by their SUMOylation, but the mechanism by which As2O3 induces this posttranslational modification is unclear. Here we show that arsenic binds directly to cysteine residues in zinc fingers located within the RBCC domain of PML-RARalpha and PML. Arsenic binding induces PML oligomerization, which increases its interaction with the small ubiquitin-like protein modifier (SUMO)-conjugating enzyme UBC9, resulting in enhanced SUMOylation and degradation. The identification of PML as a direct target of As2O3 provides new insights into the drug's mechanism of action and its specificity for APL.

Functional identification of MdSIZ1 as a SUMO E3 ligase in apple.

PubMed

Zhang, Rui-Fen; Guo, Ying; Li, Yuan-Yuan; Zhou, Li-Jie; Hao, Yu-Jin; You, Chun-Xiang

2016-07-01

SUMOylation, the conjugation of target proteins with SUMO (small ubiquitin-related modifier), is a type of post-translational modification in eukaryotes and involves the sequential action of activation (E1), conjugation (E2) and ligation (E3) enzymes. In Arabidopsis, the AtSIZ1 protein is a SUMO E3 ligase that promotes the conjugation of SUMO proteins to target substrates. Here, we isolated and identified a SUMO E3 ligase, MdSIZ1, in apple, which was similar to AtSIZ1. SUMOylation analysis showed that MdSIZ1 had SUMO E3 ligase activity in vitro and in vivo. SUMO conjugation was increased by high temperatures, low temperatures, and abscisic acid (ABA). The ectopic expression of MdSIZ1 in Arabidopsis siz1-2 mutant plants partially complemented the morphological mutant phenotype and enhanced the levels of SUMO conjugation. Taken together, these results suggest that MdSIZ1-mediated SUMO conjugation of target proteins is an important process that regulates the adaptation of apple plants to various environmental stresses. Copyright © 2016 Elsevier GmbH. All rights reserved.

Proteome-wide analysis of SUMO2 targets in response to pathological DNA replication stress in human cells.

PubMed

Bursomanno, Sara; Beli, Petra; Khan, Asif M; Minocherhomji, Sheroy; Wagner, Sebastian A; Bekker-Jensen, Simon; Mailand, Niels; Choudhary, Chunaram; Hickson, Ian D; Liu, Ying

2015-01-01

SUMOylation is a form of post-translational modification involving covalent attachment of SUMO (Small Ubiquitin-like Modifier) polypeptides to specific lysine residues in the target protein. In human cells, there are four SUMO proteins, SUMO1-4, with SUMO2 and SUMO3 forming a closely related subfamily. SUMO2/3, in contrast to SUMO1, are predominantly involved in the cellular response to certain stresses, including heat shock. Substantial evidence from studies in yeast has shown that SUMOylation plays an important role in the regulation of DNA replication and repair. Here, we report a proteomic analysis of proteins modified by SUMO2 in response to DNA replication stress in S phase in human cells. We have identified a panel of 22 SUMO2 targets with increased SUMOylation during DNA replication stress, many of which play key functions within the DNA replication machinery and/or in the cellular response to DNA damage. Interestingly, POLD3 was found modified most significantly in response to a low dose aphidicolin treatment protocol that promotes common fragile site (CFS) breakage. POLD3 is the human ortholog of POL32 in budding yeast, and has been shown to act during break-induced recombinational repair. We have also shown that deficiency of POLD3 leads to an increase in RPA-bound ssDNA when cells are under replication stress, suggesting that POLD3 plays a role in the cellular response to DNA replication stress. Considering that DNA replication stress is a source of genome instability, and that excessive replication stress is a hallmark of pre-neoplastic and tumor cells, our characterization of SUMO2 targets during a perturbed S-phase should provide a valuable resource for future functional studies in the fields of DNA metabolism and cancer biology. Copyright © 2014 Elsevier B.V. All rights reserved.

SUMO Ligase Protein Inhibitor of Activated STAT1 (PIAS1) Is a Constituent Promyelocytic Leukemia Nuclear Body Protein That Contributes to the Intrinsic Antiviral Immune Response to Herpes Simplex Virus 1

PubMed Central

Brown, James R.; Conn, Kristen L.; Wasson, Peter; Charman, Matthew; Tong, Lily; Grant, Kyle; McFarlane, Steven

2016-01-01

ABSTRACT Aspects of intrinsic antiviral immunity are mediated by promyelocytic leukemia nuclear body (PML-NB) constituent proteins. During herpesvirus infection, these antiviral proteins are independently recruited to nuclear domains that contain infecting viral genomes to cooperatively promote viral genome silencing. Central to the execution of this particular antiviral response is the small ubiquitin-like modifier (SUMO) signaling pathway. However, the participating SUMOylation enzymes are not fully characterized. We identify the SUMO ligase protein inhibitor of activated STAT1 (PIAS1) as a constituent PML-NB protein. We show that PIAS1 localizes at PML-NBs in a SUMO interaction motif (SIM)-dependent manner that requires SUMOylated or SUMOylation-competent PML. Following infection with herpes simplex virus 1 (HSV-1), PIAS1 is recruited to nuclear sites associated with viral genome entry in a SIM-dependent manner, consistent with the SIM-dependent recruitment mechanisms of other well-characterized PML-NB proteins. In contrast to that of Daxx and Sp100, however, the recruitment of PIAS1 is enhanced by PML. PIAS1 promotes the stable accumulation of SUMO1 at nuclear sites associated with HSV-1 genome entry, whereas the accumulation of other evaluated PML-NB proteins occurs independently of PIAS1. We show that PIAS1 cooperatively contributes to HSV-1 restriction through mechanisms that are additive to those of PML and cooperative with those of PIAS4. The antiviral mechanisms of PIAS1 are counteracted by ICP0, the HSV-1 SUMO-targeted ubiquitin ligase, which disrupts the recruitment of PIAS1 to nuclear domains that contain infecting HSV-1 genomes through mechanisms that do not directly result in PIAS1 degradation. IMPORTANCE Adaptive, innate, and intrinsic immunity cooperatively and efficiently restrict the propagation of viral pathogens. Intrinsic immunity mediated by constitutively expressed cellular proteins represents the first line of intracellular defense against infection. PML-NB constituent proteins mediate aspects of intrinsic immunity to restrict herpes simplex virus 1 (HSV-1) as well as other viruses. These proteins repress viral replication through mechanisms that rely on SUMO signaling. However, the participating SUMOylation enzymes are not known. We identify the SUMO ligase PIAS1 as a constituent PML-NB antiviral protein. This finding distinguishes a SUMO ligase that may mediate signaling events important in PML-NB-mediated intrinsic immunity. Moreover, this research complements the recent identification of PIAS4 as an intrinsic antiviral factor, supporting a role for PIAS proteins as both positive and negative regulators of host immunity to virus infection. PMID:27099310

SUMO Ligase Protein Inhibitor of Activated STAT1 (PIAS1) Is a Constituent Promyelocytic Leukemia Nuclear Body Protein That Contributes to the Intrinsic Antiviral Immune Response to Herpes Simplex Virus 1.

PubMed

Brown, James R; Conn, Kristen L; Wasson, Peter; Charman, Matthew; Tong, Lily; Grant, Kyle; McFarlane, Steven; Boutell, Chris

2016-07-01

Aspects of intrinsic antiviral immunity are mediated by promyelocytic leukemia nuclear body (PML-NB) constituent proteins. During herpesvirus infection, these antiviral proteins are independently recruited to nuclear domains that contain infecting viral genomes to cooperatively promote viral genome silencing. Central to the execution of this particular antiviral response is the small ubiquitin-like modifier (SUMO) signaling pathway. However, the participating SUMOylation enzymes are not fully characterized. We identify the SUMO ligase protein inhibitor of activated STAT1 (PIAS1) as a constituent PML-NB protein. We show that PIAS1 localizes at PML-NBs in a SUMO interaction motif (SIM)-dependent manner that requires SUMOylated or SUMOylation-competent PML. Following infection with herpes simplex virus 1 (HSV-1), PIAS1 is recruited to nuclear sites associated with viral genome entry in a SIM-dependent manner, consistent with the SIM-dependent recruitment mechanisms of other well-characterized PML-NB proteins. In contrast to that of Daxx and Sp100, however, the recruitment of PIAS1 is enhanced by PML. PIAS1 promotes the stable accumulation of SUMO1 at nuclear sites associated with HSV-1 genome entry, whereas the accumulation of other evaluated PML-NB proteins occurs independently of PIAS1. We show that PIAS1 cooperatively contributes to HSV-1 restriction through mechanisms that are additive to those of PML and cooperative with those of PIAS4. The antiviral mechanisms of PIAS1 are counteracted by ICP0, the HSV-1 SUMO-targeted ubiquitin ligase, which disrupts the recruitment of PIAS1 to nuclear domains that contain infecting HSV-1 genomes through mechanisms that do not directly result in PIAS1 degradation. Adaptive, innate, and intrinsic immunity cooperatively and efficiently restrict the propagation of viral pathogens. Intrinsic immunity mediated by constitutively expressed cellular proteins represents the first line of intracellular defense against infection. PML-NB constituent proteins mediate aspects of intrinsic immunity to restrict herpes simplex virus 1 (HSV-1) as well as other viruses. These proteins repress viral replication through mechanisms that rely on SUMO signaling. However, the participating SUMOylation enzymes are not known. We identify the SUMO ligase PIAS1 as a constituent PML-NB antiviral protein. This finding distinguishes a SUMO ligase that may mediate signaling events important in PML-NB-mediated intrinsic immunity. Moreover, this research complements the recent identification of PIAS4 as an intrinsic antiviral factor, supporting a role for PIAS proteins as both positive and negative regulators of host immunity to virus infection. Copyright © 2016 Brown et al.

RFWD3-Dependent Ubiquitination of RPA Regulates Repair at Stalled Replication Forks.

PubMed

Elia, Andrew E H; Wang, David C; Willis, Nicholas A; Boardman, Alexander P; Hajdu, Ildiko; Adeyemi, Richard O; Lowry, Elizabeth; Gygi, Steven P; Scully, Ralph; Elledge, Stephen J

2015-10-15

We have used quantitative proteomics to profile ubiquitination in the DNA damage response (DDR). We demonstrate that RPA, which functions as a protein scaffold in the replication stress response, is multiply ubiquitinated upon replication fork stalling. Ubiquitination of RPA occurs on chromatin, involves sites outside its DNA binding channel, does not cause proteasomal degradation, and increases under conditions of fork collapse, suggesting a role in repair at stalled forks. We demonstrate that the E3 ligase RFWD3 mediates RPA ubiquitination. RFWD3 is necessary for replication fork restart, normal repair kinetics during replication stress, and homologous recombination (HR) at stalled replication forks. Mutational analysis suggests that multisite ubiquitination of the entire RPA complex is responsible for repair at stalled forks. Multisite protein group sumoylation is known to promote HR in yeast. Our findings reveal a similar requirement for multisite protein group ubiquitination during HR at stalled forks in mammalian cells. Copyright © 2015 Elsevier Inc. All rights reserved.

SENP1-mediated NEMO deSUMOylation in adipocytes limits inflammatory responses and type-1 diabetes progression

PubMed Central

Shao, Lan; Zhou, Huanjiao Jenny; Zhang, Haifeng; Qin, Lingfeng; Hwa, John; Yun, Zhong; Ji, Weidong; Min, Wang

2015-01-01

Adipocyte dysfunction correlates with the development of diabetes. Here we show that mice with a adipocyte-specific deletion of the SUMO-specific protease SENP1 gene develop symptoms of type-1 diabetes mellitus (T1DM), including hyperglycaemia and glucose intolerance with mild insulin resistance. Peri-pancreatic adipocytes from SENP1-deficient mice exhibit heightened NF-κB activity and production of proinflammatory cytokines, which induce CCL5 expression in adjacent pancreatic islets and direct cytotoxic effects on pancreatic islets. Mechanistic studies show that SENP1 deletion in adipocytes enhances SUMOylation of the NF-κB essential molecule, NEMO, at lysine 277/309, leading to increased NF-κB activity, cytokine production and pancreatic inflammation. We further show that NF-κB inhibitors could inhibit pre-diabetic cytokine production, β-cell damages and ameliorate the T1DM phenotype in SENP1-deficient mice. Feeding a high-fat diet augments both type-1 and type-2 diabetes phenotypes in SENP1-deficient mice, consistent with the effects on adipocyte-derived NF-κB and cytokine signalling. Our study reveals previously unrecognized mechanism regulating the onset and progression of T1DM associated with adipocyte dysfunction. PMID:26596471

SENP1-mediated NEMO deSUMOylation in adipocytes limits inflammatory responses and type-1 diabetes progression.

PubMed

Shao, Lan; Zhou, Huanjiao Jenny; Zhang, Haifeng; Qin, Lingfeng; Hwa, John; Yun, Zhong; Ji, Weidong; Min, Wang

2015-11-24

Adipocyte dysfunction correlates with the development of diabetes. Here we show that mice with a adipocyte-specific deletion of the SUMO-specific protease SENP1 gene develop symptoms of type-1 diabetes mellitus (T1DM), including hyperglycaemia and glucose intolerance with mild insulin resistance. Peri-pancreatic adipocytes from SENP1-deficient mice exhibit heightened NF-κB activity and production of proinflammatory cytokines, which induce CCL5 expression in adjacent pancreatic islets and direct cytotoxic effects on pancreatic islets. Mechanistic studies show that SENP1 deletion in adipocytes enhances SUMOylation of the NF-κB essential molecule, NEMO, at lysine 277/309, leading to increased NF-κB activity, cytokine production and pancreatic inflammation. We further show that NF-κB inhibitors could inhibit pre-diabetic cytokine production, β-cell damages and ameliorate the T1DM phenotype in SENP1-deficient mice. Feeding a high-fat diet augments both type-1 and type-2 diabetes phenotypes in SENP1-deficient mice, consistent with the effects on adipocyte-derived NF-κB and cytokine signalling. Our study reveals previously unrecognized mechanism regulating the onset and progression of T1DM associated with adipocyte dysfunction.

ATL response to arsenic/interferon therapy is triggered by SUMO/PML/RNF4-dependent Tax degradation.

PubMed

Dassouki, Zeina; Sahin, Umut; El Hajj, Hiba; Jollivet, Florence; Kfoury, Youmna; Lallemand-Breitenbach, Valérie; Hermine, Olivier; de Thé, Hugues; Bazarbachi, Ali

2015-01-15

The human T-cell lymphotropic virus type I (HTLV-1) Tax transactivator initiates transformation in adult T-cell leukemia/lymphoma (ATL), a highly aggressive chemotherapy-resistant malignancy. The arsenic/interferon combination, which triggers degradation of the Tax oncoprotein, selectively induces apoptosis of ATL cell lines and has significant clinical activity in Tax-driven murine ATL or human patients. However, the role of Tax loss in ATL response is disputed, and the molecular mechanisms driving degradation remain elusive. Here we demonstrate that ATL-derived or HTLV-1-transformed cells are dependent on continuous Tax expression, suggesting that Tax degradation underlies clinical responses to the arsenic/interferon combination. The latter enforces promyelocytic leukemia protein (PML) nuclear body (NB) formation and partner protein recruitment. In arsenic/interferon-treated HTLV-1 transformed or ATL cells, Tax is recruited onto NBs and undergoes PML-dependent hyper-sumoylation by small ubiquitin-like modifier (SUMO)2/3 but not SUMO1, ubiquitination by RNF4, and proteasome-dependent degradation. Thus, the arsenic/interferon combination clears ATL through degradation of its Tax driver, and this regimen could have broader therapeutic value by promoting degradation of other pathogenic sumoylated proteins. © 2015 by The American Society of Hematology.

Protein SUMOylation is Involved in Cell-cycle Progression and Cell Morphology in Giardia lamblia.

PubMed

Di Genova, Bruno M; da Silva, Richard C; da Cunha, Júlia P C; Gargantini, Pablo R; Mortara, Renato A; Tonelli, Renata R

2017-07-01

The unicellular protozoa Giardia lamblia is a food- and waterborne parasite that causes giardiasis. This illness is manifested as acute and self-limited diarrhea and can evolve to long-term complications. Successful establishment of infection by Giardia trophozoites requires adhesion to host cells and colonization of the small intestine, where parasites multiply by mitotic division. The tight binding of trophozoites to host cells occurs by means of the ventral adhesive disc, a spiral array of microtubules and associated proteins such as giardins. In this work we show that knock down of the Small Ubiquitin-like MOdifier (SUMO) results in less adhesive trophzoites, decreased cell proliferation and deep morphological alterations, including at the ventral disc. Consistent with the reduced proliferation, SUMO knocked-down trophozoites were arrested in G1 and in S phases of the cell cycle. Mass spectrometry analysis of anti-SUMO immunoprecipitates was performed to identify SUMO substrates possibly involved in these events. Among the identified SUMOylation targets, α-tubulin was further validated by Western blot and confirmed to be a SUMO target in Giardia trophozoites. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

Promyelocytic Leukemia Protein (PML) Controls Listeria monocytogenes Infection

PubMed Central

Ribet, David; Lallemand-Breitenbach, Valérie; Ferhi, Omar; Nahori, Marie-Anne; Varet, Hugo

2017-01-01

ABSTRACT The promyelocytic leukemia protein (PML) is the main organizer of stress-responsive subnuclear structures called PML nuclear bodies. These structures recruit multiple interactors and modulate their abundance or their posttranslational modifications, notably by the SUMO ubiquitin-like modifiers. The involvement of PML in antiviral responses is well established. In contrast, the role of PML in bacterial infection remains poorly characterized. Here, we show that PML restricts infection by the pathogenic bacterium Listeria monocytogenes but not by Salmonella enterica serovar Typhimurium. During infection, PML undergoes oxidation-mediated multimerization, associates with the nuclear matrix, and becomes de-SUMOylated due to the pore-forming activity of the Listeria toxin listeriolysin O (LLO). These events trigger an antibacterial response that is not observed during in vitro infection by an LLO-defective Listeria mutant, but which can be phenocopied by specific induction of PML de-SUMOylation. Using transcriptomic and proteomic microarrays, we also characterized a network of immunity genes and cytokines, which are regulated by PML in response to Listeria infection but independently from the listeriolysin O toxin. Our study thus highlights two mechanistically distinct complementary roles of PML in host responses against bacterial infection. PMID:28074026

Regulation of Plant Cellular and Organismal Development by SUMO.

PubMed

Elrouby, Nabil

2017-01-01

This chapter clearly demonstrates the breadth and spectrum of the processes that SUMO regulates during plant development. The gross phenotypes observed in mutants of the SUMO conjugation and deconjugation enzymes reflect these essential roles, and detailed analyses of these mutants under different growth conditions revealed roles in biotic and abiotic stress responses, phosphate starvation, nitrate and sulphur metabolism, freezing and drought tolerance and response to excess copper. SUMO functions also intersect with those regulated by several hormones such as salicylic acid , abscisic acid , gibberellins and auxin, and detailed studies provide mechanistic clues of how sumoylation may regulate these processes. The regulation of COP1 and PhyB functions by sumoylation provides very strong evidence that SUMO is heavily involved in the regulation of light signaling in plants. At the cellular and subcellular levels, SUMO regulates meristem architecture, the switch from the mitotic cycle into the endocycle, meiosis, centromere decondensation and exit from mitosis, transcriptional control, and release from transcriptional silencing. Most of these advances in our understanding of SUMO functions during plant development emerged over the past 6-7 years, and they may only predict a prominent rise of SUMO as a major regulator of eukaryotic cellular and organismal growth and development.

Localization and function of KLF4 in cytoplasm of vascular smooth muscle cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Yan; The Third Hospital of Hebei Medical University, Shijazhuang; Zheng, Bin

2013-06-28

Highlights: •PDGF-BB prompts the translocation of KLF4 to the cytoplasm. •PDGF-BB promotes interaction between KLF4 and actin in the cytoplasm. •Phosphorylation and SUMOylation of KLF4 participates in regulation of cytoskeletal organization. •KLF4 regulates cytoskeleton by promoting the expression of contraction-associated genes. -- Abstract: The Krüppel-like factor 4 is a DNA-binding transcriptional regulator that regulates a diverse array of cellular processes, including development, differentiation, proliferation, and apoptosis. The previous studies about KLF4 functions mainly focused on its role as a transcription factor, its functions in the cytoplasm are still unknown. In this study, we found that PDGF-BB could prompt the translocationmore » of KLF4 to the cytoplasm through CRM1-mediated nuclear export pathway in vascular smooth muscle cells (VSMCs) and increased the interaction of KLF4 with actin in the cytoplasm. Further study showed that both KLF4 phosphorylation and SUMOylation induced by PDGF-BB participates in regulation of cytoskeletal organization by stabilizing the actin cytoskeleton in VSMCs. In conclusion, these results identify that KLF4 participates in the cytoskeletal organization by stabilizing cytoskeleton in the cytoplasm of VSMCs.« less

Impaired endocytosis of the ion channel TRPM4 is associated with human progressive familial heart block type I.

PubMed

Kruse, Martin; Schulze-Bahr, Eric; Corfield, Valerie; Beckmann, Alf; Stallmeyer, Birgit; Kurtbay, Güven; Ohmert, Iris; Schulze-Bahr, Ellen; Brink, Paul; Pongs, Olaf

2009-09-01

Progressive familial heart block type I (PFHBI) is a progressive cardiac bundle branch disease in the His-Purkinje system that exhibits autosomal-dominant inheritance. In 3 branches of a large South African Afrikaner pedigree with an autosomal-dominant form of PFHBI, we identified the mutation c.19G-->A in the transient receptor potential cation channel, subfamily M, member 4 gene (TRPM4) at chromosomal locus 19q13.3. This mutation predicted the amino acid substitution p.E7K in the TRPM4 amino terminus. TRPM4 encodes a Ca2+-activated nonselective cation (CAN) channel that belongs to the transient receptor potential melastatin ion channel family. Quantitative analysis of TRPM4 mRNA content in human cardiac tissue showed the highest expression level in Purkinje fibers. Cellular expression studies showed that the c.19G-->A missense mutation attenuated deSUMOylation of the TRPM4 channel. The resulting constitutive SUMOylation of the mutant TRPM4 channel impaired endocytosis and led to elevated TRPM4 channel density at the cell surface. Our data therefore revealed a gain-of-function mechanism underlying this type of familial heart block.

Impaired endocytosis of the ion channel TRPM4 is associated with human progressive familial heart block type I

PubMed Central

Kruse, Martin; Schulze-Bahr, Eric; Corfield, Valerie; Beckmann, Alf; Stallmeyer, Birgit; Kurtbay, Güven; Ohmert, Iris; Schulze-Bahr, Ellen; Brink, Paul; Pongs, Olaf

2009-01-01

Progressive familial heart block type I (PFHBI) is a progressive cardiac bundle branch disease in the His-Purkinje system that exhibits autosomal-dominant inheritance. In 3 branches of a large South African Afrikaner pedigree with an autosomal-dominant form of PFHBI, we identified the mutation c.19G→A in the transient receptor potential cation channel, subfamily M, member 4 gene (TRPM4) at chromosomal locus 19q13.3. This mutation predicted the amino acid substitution p.E7K in the TRPM4 amino terminus. TRPM4 encodes a Ca2+-activated nonselective cation (CAN) channel that belongs to the transient receptor potential melastatin ion channel family. Quantitative analysis of TRPM4 mRNA content in human cardiac tissue showed the highest expression level in Purkinje fibers. Cellular expression studies showed that the c.19G→A missense mutation attenuated deSUMOylation of the TRPM4 channel. The resulting constitutive SUMOylation of the mutant TRPM4 channel impaired endocytosis and led to elevated TRPM4 channel density at the cell surface. Our data therefore revealed a gain-of-function mechanism underlying this type of familial heart block. PMID:19726882

Asy2/Mer2: an evolutionarily conserved mediator of meiotic recombination, pairing, and global chromosome compaction

PubMed Central

Tessé, Sophie; Bourbon, Henri-Marc; Debuchy, Robert; Budin, Karine; Dubois, Emeline; Liangran, Zhang; Antoine, Romain; Piolot, Tristan; Kleckner, Nancy; Zickler, Denise; Espagne, Eric

2017-01-01

Meiosis is the cellular program by which a diploid cell gives rise to haploid gametes for sexual reproduction. Meiotic progression depends on tight physical and functional coupling of recombination steps at the DNA level with specific organizational features of meiotic-prophase chromosomes. The present study reveals that every step of this coupling is mediated by a single molecule: Asy2/Mer2. We show that Mer2, identified so far only in budding and fission yeasts, is in fact evolutionarily conserved from fungi (Mer2/Rec15/Asy2/Bad42) to plants (PRD3/PAIR1) and mammals (IHO1). In yeasts, Mer2 mediates assembly of recombination–initiation complexes and double-strand breaks (DSBs). This role is conserved in the fungus Sordaria. However, functional analysis of 13 mer2 mutants and successive localization of Mer2 to axis, synaptonemal complex (SC), and chromatin revealed, in addition, three further important functions. First, after DSB formation, Mer2 is required for pairing by mediating homolog spatial juxtaposition, with implications for crossover (CO) patterning/interference. Second, Mer2 participates in the transfer/maintenance and release of recombination complexes to/from the SC central region. Third, after completion of recombination, potentially dependent on SUMOylation, Mer2 mediates global chromosome compaction and post-recombination chiasma development. Thus, beyond its role as a recombinosome–axis/SC linker molecule, Mer2 has important functions in relation to basic chromosome structure. PMID:29021238

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Ronghai; Zhang, Ping, E-mail: zpskx001@163.com; Li, Jinhang

The hypoxia-inducible factor (HIF) is recognized as the master regulator of hypoxia response. HIF-α subunits expression are tightly regulated. In this study, our data show that ts20 cells still expressed detectable E1 protein even at 39.5° C for 12 h, and complete depletion of E1 protein expression at 39.5° C by siRNA enhanced HIF-1α and P53 protein expression. Further inhibition of E1 at 39.5 °C by siRNA, or E1 inhibitor Ube1-41 completely blocked HIF-1α degradation. Moreover, immunoprecipitations of co-transfection of HA-ubiquitin and FLAG–HIF–1α plasmids directly confirmed the involvement of ubiquitin in the hypoxic degradation of HIF-1α. Additionally, hypoxic HIF-1 α degradation is independent ofmore » HAF, RACK1, sumoylation or nuclear/cytoplasmic localization. Taken together, our data suggest that constitutive HIF-1α protein degradation in hypoxia is absolutely ubiquitination-dependent, and unidentified E3 ligase may exist for this degradation pathway. - Highlights: • HIF-1α protein is constitutively degraded in hypoxic conditions. • Requirement of ubiquitination for HIF-1α degradation in hypoxia. • Hypoxic HIF-1α degradation is independent of HAF, RACK1, sumoylation or nuclear/cytoplasmic localization.« less

Quantitative Analysis of Subcellular Distribution of the SUMO Conjugation System by Confocal Microscopy Imaging.

PubMed

Mas, Abraham; Amenós, Montse; Lois, L Maria

2016-01-01

Different studies point to an enrichment in SUMO conjugation in the cell nucleus, although non-nuclear SUMO targets also exist. In general, the study of subcellular localization of proteins is essential for understanding their function within a cell. Fluorescence microscopy is a powerful tool for studying subcellular protein partitioning in living cells, since fluorescent proteins can be fused to proteins of interest to determine their localization. Subcellular distribution of proteins can be influenced by binding to other biomolecules and by posttranslational modifications. Sometimes these changes affect only a portion of the protein pool or have a partial effect, and a quantitative evaluation of fluorescence images is required to identify protein redistribution among subcellular compartments. In order to obtain accurate data about the relative subcellular distribution of SUMO conjugation machinery members, and to identify the molecular determinants involved in their localization, we have applied quantitative confocal microscopy imaging. In this chapter, we will describe the fluorescent protein fusions used in these experiments, and how to measure, evaluate, and compare average fluorescence intensities in cellular compartments by image-based analysis. We show the distribution of some components of the Arabidopsis SUMOylation machinery in epidermal onion cells and how they change their distribution in the presence of interacting partners or even when its activity is affected.

Interplay between Ubiquitin, SUMO, and Poly(ADP-Ribose) in the Cellular Response to Genotoxic Stress

PubMed Central

Pellegrino, Stefania; Altmeyer, Matthias

2016-01-01

Cells employ a complex network of molecular pathways to cope with endogenous and exogenous genotoxic stress. This multilayered response ensures that genomic lesions are efficiently detected and faithfully repaired in order to safeguard genome integrity. The molecular choreography at sites of DNA damage relies heavily on post-translational modifications (PTMs). Protein modifications with ubiquitin and the small ubiquitin-like modifier SUMO have recently emerged as important regulatory means to coordinate DNA damage signaling and repair. Both ubiquitylation and SUMOylation can lead to extensive chain-like protein modifications, a feature that is shared with yet another DNA damage-induced PTM, the modification of proteins with poly(ADP-ribose) (PAR). Chains of ubiquitin, SUMO, and PAR all contribute to the multi-protein assemblies found at sites of DNA damage and regulate their spatio-temporal dynamics. Here, we review recent advancements in our understanding of how ubiquitin, SUMO, and PAR coordinate the DNA damage response and highlight emerging examples of an intricate interplay between these chain-like modifications during the cellular response to genotoxic stress. PMID:27148359

The story so far: post-translational regulation of peroxisome proliferator-activated receptors by ubiquitination and SUMOylation

PubMed Central

Wadosky, Kristine M.

2012-01-01

Many studies have implicated the peroxisome proliferator-activated receptor (PPAR) family of nuclear receptor transcription factors in regulating cardiac substrate metabolism and ATP generation. Recently, evidence from a variety of cell culture and organ systems has implicated ubiquitin and small ubiquitin-like modifier (SUMO) conjugation as post-translational modifications that regulate the activity of PPAR transcription factors and their coreceptors/coactivators. Here we introduce the ubiquitin and SUMO conjugation systems and extensively review how they have been shown to regulate all three PPAR isoforms (PPARα, PPARβ/δ, and PPARγ) in addition to the retinoid X receptor and PPARγ coactivator-1α subunits of the larger PPAR transcription factor complex. We then present how the specific ubiquitin (E3) ligases have been implicated and review emerging evidence that post-translational modifications of PPARs with ubiquitin and/or SUMO may play a role in cardiac disease. Because PPAR activity is perturbed in a variety of forms of heart disease and specific proteins regulate this process (E3 ligases), this may be a fruitful area of investigation with respect to finding new therapeutic targets. PMID:22037188

The Integrative Studies of Genetic and Environmental Factors in Systemic Sclerosis

DTIC Science & Technology

2010-05-01

nucleolus and the nucleoplasm, but is enriched in the nucleolus where there is a high level of transcription and replication of the ribosomal DNA (6,7...residues. Sumoylation of topo I has been shown to facilitate its movement between the nucleolus and the nucleoplasm (8-10). The purpose of this...strong nucleoplasm staining (multiple speckles) compared to normal fibroblasts in which topo I staining showed normal enrichment in the nucleolus

Cholesterol negatively regulates IL-9-producing CD8+ T cell differentiation and antitumor activity.

PubMed

Ma, Xingzhe; Bi, Enguang; Huang, Chunjian; Lu, Yong; Xue, Gang; Guo, Xing; Wang, Aibo; Yang, Maojie; Qian, Jianfei; Dong, Chen; Yi, Qing

2018-05-09

CD8 + T cells can be polarized into IL-9-secreting (Tc9) cells. We previously showed that adoptive therapy using tumor-specific Tc9 cells generated stronger antitumor responses in mouse melanoma than classical Tc1 cells. To understand why Tc9 cells exert stronger antitumor responses, we used gene profiling to compare Tc9 and Tc1 cells. Tc9 cells expressed different levels of cholesterol synthesis and efflux genes and possessed significantly lower cholesterol content than Tc1 cells. Unique to Tc9, but not other CD8 + or CD4 + T cell subsets, manipulating cholesterol content in polarizing Tc9 cells significantly affected IL-9 expression and Tc9 differentiation and antitumor response in vivo. Mechanistic studies showed that IL-9 was indispensable for Tc9 cell persistence and antitumor effects, and cholesterol or its derivatives inhibited IL-9 expression by activating liver X receptors (LXRs), leading to LXR Sumoylation and reduced p65 binding to Il9 promoter. Our study identifies cholesterol as a critical regulator of Tc9 cell differentiation and function. © 2018 Ma et al.

The Epstein-Barr virus miR-BHRF1-1 targets RNF4 during productive infection to promote the accumulation of SUMO conjugates and the release of infectious virus.

PubMed

Li, Jinlin; Callegari, Simone; Masucci, Maria G

2017-04-01

Post-translational modification by the Small Ubiquitin-like Modifier (SUMO) regulates a variety of cellular functions, and is hijacked by viruses to remodel the host cell during latent and productive infection. Here we have monitored the activity of the SUMO conjugation machinery in cells productively infected with Epstein-Barr virus (EBV). We found that SUMO2/3 conjugates accumulate during the late phase of the productive virus cycle, and identified several viral proteins as bone fide SUMOylation substrates. Analysis of the mechanism involved in the accumulation of SUMOylated proteins revealed upregulation of several components of the SUMO-conjugation machinery and post-transcriptional downregulation of the SUMO-targeted ubiquitin ligase RNF4. The latter effect was mediated by selective inhibition of RNF4 protein expression by the viral miR-BHRF1-1. Reconstitution of RNF4 in cells expressing an inducible miR-BHRF1-1 sponge or a miR-BHRF1-1 resistant RNF4 was associated with reduced levels of early and late viral proteins and impaired virus release. These findings illustrate a novel strategy for viral interference with the SUMO pathway, and identify the EBV miR-BHRF1-1 and the cellular RNF4 as regulators of the productive virus cycle.

A novel quantitative high-throughput screen identifies drugs that both activate SUMO conjugation via the inhibition of microRNAs 182 and 183 and facilitate neuroprotection in a model of oxygen and glucose deprivation

PubMed Central

Bernstock, Joshua D; Lee, Yang-ja; Peruzzotti-Jametti, Luca; Southall, Noel; Johnson, Kory R; Maric, Dragan; Volpe, Giulio; Kouznetsova, Jennifer; Zheng, Wei; Pluchino, Stefano

2015-01-01

The conjugation/de-conjugation of Small Ubiquitin-like Modifier (SUMO) has been shown to be associated with a diverse set of physiologic/pathologic conditions. The clinical significance and ostensible therapeutic utility offered via the selective control of the global SUMOylation process has become readily apparent in ischemic pathophysiology. Herein, we describe the development of a novel quantitative high-throughput screening (qHTS) system designed to identify small molecules capable of increasing SUMOylation via the regulation/inhibition of members of the microRNA (miRNA)-182 family. This assay employs a SHSY5Y human neuroblastoma cell line stably transfected with a dual firefly-Renilla luciferase reporter system for identification of specific inhibitors of either miR-182 or miR-183. In this study, we have identified small molecules capable of inducing increased global conjugation of SUMO in both SHSY5Y cells and rat E18-derived primary cortical neurons. The protective effects of a number of the identified compounds were confirmed via an in vitro ischemic model (oxygen/glucose deprivation). Of note, this assay can be easily repurposed to allow high-throughput analyses of the potential drugability of other relevant miRNA(s) in ischemic pathobiology. PMID:26661196

The Epstein-Barr virus miR-BHRF1-1 targets RNF4 during productive infection to promote the accumulation of SUMO conjugates and the release of infectious virus

PubMed Central

Li, Jinlin; Callegari, Simone

2017-01-01

Post-translational modification by the Small Ubiquitin-like Modifier (SUMO) regulates a variety of cellular functions, and is hijacked by viruses to remodel the host cell during latent and productive infection. Here we have monitored the activity of the SUMO conjugation machinery in cells productively infected with Epstein-Barr virus (EBV). We found that SUMO2/3 conjugates accumulate during the late phase of the productive virus cycle, and identified several viral proteins as bone fide SUMOylation substrates. Analysis of the mechanism involved in the accumulation of SUMOylated proteins revealed upregulation of several components of the SUMO-conjugation machinery and post-transcriptional downregulation of the SUMO-targeted ubiquitin ligase RNF4. The latter effect was mediated by selective inhibition of RNF4 protein expression by the viral miR-BHRF1-1. Reconstitution of RNF4 in cells expressing an inducible miR-BHRF1-1 sponge or a miR-BHRF1-1 resistant RNF4 was associated with reduced levels of early and late viral proteins and impaired virus release. These findings illustrate a novel strategy for viral interference with the SUMO pathway, and identify the EBV miR-BHRF1-1 and the cellular RNF4 as regulators of the productive virus cycle. PMID:28414785

Quantitative Förster resonance energy transfer analysis for kinetic determinations of SUMO-specific protease.

PubMed

Liu, Yan; Song, Yang; Madahar, Vipul; Liao, Jiayu

2012-03-01

Förster resonance energy transfer (FRET) technology has been widely used in biological and biomedical research, and it is a very powerful tool for elucidating protein interactions in either dynamic or steady state. SUMOylation (the process of SUMO [small ubiquitin-like modifier] conjugation to substrates) is an important posttranslational protein modification with critical roles in multiple biological processes. Conjugating SUMO to substrates requires an enzymatic cascade. Sentrin/SUMO-specific proteases (SENPs) act as an endopeptidase to process the pre-SUMO or as an isopeptidase to deconjugate SUMO from its substrate. To fully understand the roles of SENPs in the SUMOylation cycle, it is critical to understand their kinetics. Here, we report a novel development of a quantitative FRET-based protease assay for SENP1 kinetic parameter determination. The assay is based on the quantitative analysis of the FRET signal from the total fluorescent signal at acceptor emission wavelength, which consists of three components: donor (CyPet-SUMO1) emission, acceptor (YPet) emission, and FRET signal during the digestion process. Subsequently, we developed novel theoretical and experimental procedures to determine the kinetic parameters, k(cat), K(M), and catalytic efficiency (k(cat)/K(M)) of catalytic domain SENP1 toward pre-SUMO1. Importantly, the general principles of this quantitative FRET-based protease kinetic determination can be applied to other proteases. Copyright © 2011 Elsevier Inc. All rights reserved.

Post-translational modification of human heat shock factors and their functions: a recent update by proteomic approach.

PubMed

Xu, Yan-Ming; Huang, Dong-Yang; Chiu, Jen-Fu; Lau, Andy T Y

2012-05-04

Heat shock factors (HSFs) are vital for modulating stress and heat shock-related gene expression in cells. The activity of HSFs is controlled largely by post-translational modifications (PTMs). For example, basal phosphorylation of HSF1 on three serine sites suppresses the heat shock response, and hyperphosphorylation of HSF1 on several other serine and threonine sites by stress-activated kinases results in its activation, while acetylation on K80 inhibits its DNA-binding ability. Sumoylation of HSF2 on K82 regulates its DNA-binding ability, whereas sumoylation of HSF4B on K293 represses its transcriptional activity. With the advancement of proteomic technology, novel PTM sites on various HSFs have been identified with the use of tandem mass spectrometry (MS/MS), but the functions of many of these PTMs are still unclear. Yet, it should be noted that the discovery of these novel PTM sites provided the necessary evidence for the existence of these PTM marks in vivo. Followed by subsequent functional analysis, this would ultimately lead to a better understanding of these PTM marks. MS/MS-based proteomic approach is becoming a gold standard in PTM validation in the field of life science. Here, the recent literature of all known PTMs reported on human HSFs and the resulting functions will be discussed.

Structural and Functional Investigations of the N-Terminal Ubiquitin Binding Region of Usp25.

PubMed

Yang, Yuanyuan; Shi, Li; Ding, Yiluan; Shi, Yanhong; Hu, Hong-Yu; Wen, Yi; Zhang, Naixia

2017-05-23

Ubiquitin-specific protease 25 (Usp25) is a deubiquitinase that is involved in multiple biological processes. The N-terminal ubiquitin-binding region (UBR) of Usp25 contains one ubiquitin-associated domain, one small ubiquitin-like modifier (SUMO)-interacting motif and two ubiquitin-interacting motifs. Previous studies suggest that the covalent sumoylation in the UBR of Usp25 impairs its enzymatic activity. Here, we raise the hypothesis that non-covalent binding of SUMO, a prerequisite for efficient sumoylation, will impair Usp25's catalytic activity as well. To test our hypothesis and elucidate the underlying molecular mechanism, we investigated the structure and function of the Usp25 N-terminal UBR. The solution structure of Usp25 1-146 is obtained, and the key residues responsible for recognition of ubiquitin and SUMO2 are identified. Our data suggest inhibition of Usp25's catalytic activity upon the non-covalent binding of SUMO2 to the Usp25 SUMO-interacting motif. We also find that SUMO2 can competitively block the interaction between the Usp25 UBR and its ubiquitin substrates. Based on our findings, we have proposed a working model to depict the regulatory role of the Usp25 UBR in the functional display of the enzyme. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Asy2/Mer2: an evolutionarily conserved mediator of meiotic recombination, pairing, and global chromosome compaction.

PubMed

Tessé, Sophie; Bourbon, Henri-Marc; Debuchy, Robert; Budin, Karine; Dubois, Emeline; Liangran, Zhang; Antoine, Romain; Piolot, Tristan; Kleckner, Nancy; Zickler, Denise; Espagne, Eric

2017-09-15

Meiosis is the cellular program by which a diploid cell gives rise to haploid gametes for sexual reproduction. Meiotic progression depends on tight physical and functional coupling of recombination steps at the DNA level with specific organizational features of meiotic-prophase chromosomes. The present study reveals that every step of this coupling is mediated by a single molecule: Asy2/Mer2. We show that Mer2, identified so far only in budding and fission yeasts, is in fact evolutionarily conserved from fungi (Mer2/Rec15/Asy2/Bad42) to plants (PRD3/PAIR1) and mammals (IHO1). In yeasts, Mer2 mediates assembly of recombination-initiation complexes and double-strand breaks (DSBs). This role is conserved in the fungus Sordaria However, functional analysis of 13 mer2 mutants and successive localization of Mer2 to axis, synaptonemal complex (SC), and chromatin revealed, in addition, three further important functions. First, after DSB formation, Mer2 is required for pairing by mediating homolog spatial juxtaposition, with implications for crossover (CO) patterning/interference. Second, Mer2 participates in the transfer/maintenance and release of recombination complexes to/from the SC central region. Third, after completion of recombination, potentially dependent on SUMOylation, Mer2 mediates global chromosome compaction and post-recombination chiasma development. Thus, beyond its role as a recombinosome-axis/SC linker molecule, Mer2 has important functions in relation to basic chromosome structure. © 2017 Tessé et al.; Published by Cold Spring Harbor Laboratory Press.

BEND3 represses rDNA transcription by stabilizing a NoRC component via USP21 deubiquitinase

PubMed Central

Khan, Abid; Giri, Sumanprava; Wang, Yating; Chakraborty, Arindam; Ghosh, Archit K.; Anantharaman, Aparna; Aggarwal, Vasudha; Sathyan, Kizhakke M.; Ha, Taekjip; Prasanth, Kannanganattu V.; Prasanth, Supriya G.

2015-01-01

Ribosome biogenesis dictates the translational capacity of cells. Several mechanisms establish and maintain transcriptional output from eukaryotic ribosomal DNA (rDNA) loci. rDNA silencing is one such mechanism that ensures the inactivity and hence the maintenance of a silenced state of a subset of rRNA gene copies. Whereas oncogenic agents stimulate rRNA gene transcription, tumor suppressors decrease rRNA gene transcription. We demonstrate in mammalian cells that BANP, E5R, and Nac1 (BEN) domain 3 (BEND3), a quadruple BEN domain-containing protein, localizes in nucleoli and binds to ribosomal RNA gene promoters to help repress rRNA genes. Loss of BEND3 increases histone H3K4 trimethylation and, correspondingly, decreases rDNA promoter DNA methylation, consistent with a role for BEND3 in rDNA silencing. BEND3 associates with the nucleolar-remodeling complex (NoRC), and SUMOylated BEND3 stabilizes NoRC component TTF-1–interacting protein 5 via association with ubiquitin specific protease 21 (USP21) debiquitinase. Our results provide mechanistic insights into how the novel rDNA transcription repressor BEND3 acts together with NoRC to actively coordinate the establishment of rDNA silencing. PMID:26100909

BEND3 represses rDNA transcription by stabilizing a NoRC component via USP21 deubiquitinase.

PubMed

Khan, Abid; Giri, Sumanprava; Wang, Yating; Chakraborty, Arindam; Ghosh, Archit K; Anantharaman, Aparna; Aggarwal, Vasudha; Sathyan, Kizhakke M; Ha, Taekjip; Prasanth, Kannanganattu V; Prasanth, Supriya G

2015-07-07

Ribosome biogenesis dictates the translational capacity of cells. Several mechanisms establish and maintain transcriptional output from eukaryotic ribosomal DNA (rDNA) loci. rDNA silencing is one such mechanism that ensures the inactivity and hence the maintenance of a silenced state of a subset of rRNA gene copies. Whereas oncogenic agents stimulate rRNA gene transcription, tumor suppressors decrease rRNA gene transcription. We demonstrate in mammalian cells that BANP, E5R, and Nac1 (BEN) domain 3 (BEND3), a quadruple BEN domain-containing protein, localizes in nucleoli and binds to ribosomal RNA gene promoters to help repress rRNA genes. Loss of BEND3 increases histone H3K4 trimethylation and, correspondingly, decreases rDNA promoter DNA methylation, consistent with a role for BEND3 in rDNA silencing. BEND3 associates with the nucleolar-remodeling complex (NoRC), and SUMOylated BEND3 stabilizes NoRC component TTF-1-interacting protein 5 via association with ubiquitin specific protease 21 (USP21) debiquitinase. Our results provide mechanistic insights into how the novel rDNA transcription repressor BEND3 acts together with NoRC to actively coordinate the establishment of rDNA silencing.

Engineering pre-SUMO4 as efficient substrate of SENP2.

PubMed

Liu, Yan; Kieslich, Chris A; Morikis, Dimitrios; Liao, Jiayu

2014-04-01

SUMOylation, one of the most important protein post-translational modifications, plays critical roles in a variety of physiological and pathological processes. SENP (Sentrin/SUMO-specific protease), a family of SUMO-specific proteases, is responsible for the processing of pre-SUMO and removal of SUMO from conjugated substrates. SUMO4, the latest discovered member in the SUMO family, has been found as a type 1 diabetes susceptibility gene and its maturation is not understood so far. Despite the 14 amino acid differences between pre-SUMO4 and SUMO2, pre-SUMO4 is not processed by SENP2 but pre-SUMO2 does. A novel interdisciplinary approach involving computational modeling and a FRET-based protease assay was taken to engineer pre-SUMO4 as a substrate of SENP2. Given the difference in net charge between pre-SUMO4 and pre-SUMO2, the computational framework analysis of electrostatic similarities of proteins was applied to determine the contribution of each ionizable amino acid in a model of SENP2-(pre-SUMO4) binding, and to propose pre-SUMO4 mutations. The specificities of the SENP2 toward different pre-SUMO4 mutants were determined using a quantitative FRET assay by characterizing the catalytic efficiencies (kcat/KM). A single amino acid mutation made pre-SUMO4 amenable to SENP2 processing and a combination of two amino acid mutations made it highly accessible as SENP2 substrate. The combination of the two approaches provides a powerful protein engineering tool for future SUMOylation studies.

Expression and in vitro functional analyses of recombinant Gam1 protein

PubMed Central

Avila, Gustavo A.; Ramirez, Daniel H.; Hildenbrand, Zacariah L.; Jacquez, Pedro; Chiocca, Susanna; Sun, Jianjun; Rosas-Acosta, German; Xiao, Chuan

2014-01-01

Gam1, an early gene product of an avian adenovirus, is essential for viral replication. Gam1 is the first viral protein found to globally inhibit cellular SUMOylation, a critical posttranslational modification that alters the function and cellular localization of proteins. The interaction details at the interface between Gam1 and its cellular targets remain unclear due to the lack of structural information. Although Gam1 has been previously characterized, the purity of the protein was not suitable for structural investigations. In the present study, the gene of Gam1 was cloned and expressed in various bacterial expression systems to obtain pure and soluble recombinant Gam1 protein for in vitro functional and structural studies. While Gam1 was insoluble in most expression systems tested, it became soluble when it was expressed as a fusion protein with trigger factor (TF), a ribosome associated bacterial chaperone, under the control of a cold shock promoter. Careful optimization indicates that both low temperature induction and the chaperone function of TF play critical roles in increasing Gam1 solubility. Soluble Gam1 was purified to homogeneity through sequential chromatography techniques. Monomeric Gam1 was obtained via size exclusion chromatography and analyzed by dynamic light scattering. The SUMOylation inhibitory function of the purified Gam1 was confirmed in an in vitro assay. These results have built the foundation for further structural investigations that will broaden our understanding of Gam1’s roles in viral replication. PMID:25450237

Expression and in vitro functional analyses of recombinant Gam1 protein.

PubMed

Avila, Gustavo A; Ramirez, Daniel H; Hildenbrand, Zacariah L; Jacquez, Pedro; Chiocca, Susanna; Sun, Jianjun; Rosas-Acosta, German; Xiao, Chuan

2015-01-01

Gam1, an early gene product of an avian adenovirus, is essential for viral replication. Gam1 is the first viral protein found to globally inhibit cellular SUMOylation, a critical posttranslational modification that alters the function and cellular localization of proteins. The interaction details at the interface between Gam1 and its cellular targets remain unclear due to the lack of structural information. Although Gam1 has been previously characterized, the purity of the protein was not suitable for structural investigations. In the present study, the gene of Gam1 was cloned and expressed in various bacterial expression systems to obtain pure and soluble recombinant Gam1 protein for in vitro functional and structural studies. While Gam1 was insoluble in most expression systems tested, it became soluble when it was expressed as a fusion protein with trigger factor (TF), a ribosome associated bacterial chaperone, under the control of a cold shock promoter. Careful optimization indicates that both low temperature induction and the chaperone function of TF play critical roles in increasing Gam1 solubility. Soluble Gam1 was purified to homogeneity through sequential chromatography techniques. Monomeric Gam1 was obtained via size exclusion chromatography and analyzed by dynamic light scattering. The SUMOylation inhibitory function of the purified Gam1 was confirmed in an in vitro assay. These results have built the foundation for further structural investigations that will broaden our understanding of Gam1's roles in viral replication. Copyright © 2014 Elsevier Inc. All rights reserved.

MEL-18 loss mediates estrogen receptor–α downregulation and hormone independence

PubMed Central

Lee, Jeong-Yeon; Won, Hee-Young; Park, Ji-Hye; Kim, Hye-Yeon; Choi, Hee-Joo; Shin, Dong-Hui; Kang, Ju-Hee; Woo, Jong-Kyu; Oh, Seung-Hyun; Son, Taekwon; Choi, Jin-Woo; Kim, Sehwan; Kim, Hyung-Yong; Yi, Kijong; Jang, Ki-Seok; Oh, Young-Ha; Kong, Gu

2015-01-01

The polycomb protein MEL-18 has been proposed as a tumor suppressor in breast cancer; however, its functional relevance to the hormonal regulation of breast cancer remains unknown. Here, we demonstrated that MEL-18 loss contributes to the hormone-independent phenotype of breast cancer by modulating hormone receptor expression. In multiple breast cancer cohorts, MEL-18 was markedly downregulated in triple-negative breast cancer (TNBC). MEL-18 expression positively correlated with the expression of luminal markers, including estrogen receptor–α (ER-α, encoded by ESR1). MEL-18 loss was also associated with poor response to antihormonal therapy in ER-α–positive breast cancer. Furthermore, whereas MEL-18 loss in luminal breast cancer cells resulted in the downregulation of expression and activity of ER-α and the progesterone receptor (PR), MEL-18 overexpression restored ER-α expression in TNBC. Consistently, in vivo xenograft experiments demonstrated that MEL-18 loss induces estrogen-independent growth and tamoxifen resistance in luminal breast cancer, and that MEL-18 overexpression confers tamoxifen sensitivity in TNBC. MEL-18 suppressed SUMOylation of the ESR1 transactivators p53 and SP1, thereby driving ESR1 transcription. MEL-18 facilitated the deSUMOylation process by inhibiting BMI-1/RING1B-mediated ubiquitin-proteasomal degradation of SUMO1/sentrin-specific protease 1 (SENP1). These findings demonstrate that MEL-18 is a SUMO-dependent regulator of hormone receptors and suggest MEL-18 expression as a marker for determining the antihormonal therapy response in patients with breast cancer. PMID:25822021

Genetic Polymorphism of SUMO-Specific Cysteine Proteases - SENP1 and SENP2 in Breast Cancer.

PubMed

Mirecka, Alicja; Morawiec, Zbigniew; Wozniak, Katarzyna

2016-10-01

SENP proteases take part in post-translational modification of proteins known as sumoylation. They catalyze three distinct processes during sumoylation: processing of SUMO protein, deconjugation of SUMO from the target protein, and chain editing which mentions to the dismantling of SUMO chain. Many proteins that are involved in the basic processes of cells, such as regulation of transcription, DNA repair or cell cycle control, are sumoylated. The aim of these studies was to investigate an association between polymorphic variants (SNPs) of the SENP1 gene (c.1691 + 36C > T, rs12297820) and SENP2 gene (c.902C > A, p.Thr301Lys, rs6762208) and a risk of breast cancer occurrence. We performed a case-control study in 324 breast cancer cases and 335 controls using PCR-RLFP. In the case of the SENP1 gene polymorphism we did not find any association between this polymorphism and breast cancer risk. In the case of SENP2 gene polymorphism we observed higher risk of breast cancer for carriers of the A allele (OR =1.33; 95 % CI 1.04-1.69). Our analysis also showed the genotype C/C (OR =0.67, 95 % CI 0.48-0.93) and the allele C (OR =0.75, 95 % CI 0.59-0.69) of this polymorphism decrease a risk of breast cancer. We also checked the distribution of genotypes and frequency of alleles of the SENP1 and SENP2 genes polymorphisms in groups of patients with different hormone receptor status, patients with positive and negative lymph node status and patients with different tumor grade. Odds ratio analysis showed a higher risk of metastases in women with the genotype C/C (OR =2.07, 95 % CI 1.06-4.05) and allele C (OR =2.10 95 % CI 1.10-4.01) of the c.1691 + 36C > T SENP1 gene polymorphism. Moreover, we observed reduced risk in women with the allele T (OR =0.48, 95 % CI 0.25-0.91) in this polymorphic site. In the case of SENP2 gene polymorphism we observed that the A/A genotype correlated with the lack of estrogen receptor (OR =1.94, 95 % CI 1.04-3.62). Our results suggest that the variability of the SENP1 and SENP2 genes may play a role in breast cancer occurrence. Further studies are needed to clarify their biological functions in breast cancer.

Srs2 overexpression reveals a helicase-independent role at replication forks that requires diverse cell functions

PubMed Central

León Ortiz, Ana María; Reid, Robert J. D.; Dittmar, John C.; Rothstein, Rodney; Nicolas, Alain

2011-01-01

Srs2 is a 3’ to 5’ DNA helicase that regulates many aspects of DNA metabolism in Saccharomyces cerevisiae. It is best known for its ability to counteract homologous recombination by dismantling Rad51 filaments, but is also involved in checkpoint activation, adaptation and recovery, and in resolution of late recombination intermediates. To further address its biological roles and uncover new genetic interactions, we examined the consequences of overexpressing SRS2 as well as two helicase-dead mutants, srs2-K41A and srs2-K41R, in the collection of 4827 yeast haploid deletion mutants. We identified 274 genes affecting a large variety of cellular functions that are required for cell growth when SRS2 or its mutants are overexpressed. Further analysis of these interactions reveals that Srs2 acts independently of its helicase function at replication forks likely through its recruitment by the sumoylated PCNA replication clamp. This helicase-independent function is responsible for the negative interactions with DNA metabolism genes and for the toxicity of SRS2 overexpression in many of the diverse cellular pathways revealed in our screens. PMID:21459050

Promyelocytic leukemia protein enhances apoptosis of gastric cancer cells through Yes-associated protein.

PubMed

Xu, Zhipeng; Chen, Jiamin; Shao, Liming; Ma, Wangqian; Xu, Dingting

2015-09-01

It has been shown that Yes-associated protein (YAP) acts as a transcriptional co-activator to regulate p73-dependent apoptosis in response to DNA damage in some cell types, and promyelocytic leukemia (PML) protein is involved in the regulation loop through stabilization of YAP through sumoylation. Although YAP has been shown to be significantly upregulated in gastric cancer, whether the YAP/PML/p73 regulation loop also functions in gastric cancer is unknown. Here, we show significantly higher levels of YAP and significantly lower levels of PML in the gastric cancer specimen. Overexpression of YAP in gastric cancer cells significantly increased cell growth, but did not affect apoptosis. However, overexpression of PML in gastric cancer cells significantly increased cell apoptosis, resulting in decreases in cell growth, which seemed to require the presence of YAP. The effect of PML on apoptosis appeared to be conducted through p73-mediated modulation of apoptosis-associated genes, Bcl-2, Bak, and caspase9. Thus, our study suggests the presence of a YAP/PML/p73 regulatory loop in gastric cancer, and highlights PML as a promising tumor suppressor in gastric cancer through YAP-coordinated cancer cell apoptosis.

X-linked Inhibitor of Apoptosis Protein (XIAP) Mediates Cancer Cell Motility via Rho GDP Dissociation Inhibitor (RhoGDI)-dependent Regulation of the Cytoskeleton*

PubMed Central

Liu, Jinyi; Zhang, Dongyun; Luo, Wenjing; Yu, Yonghui; Yu, Jianxiu; Li, Jingxia; Zhang, Xinhai; Zhang, Baolin; Chen, Jingyuan; Wu, Xue-Ru; Rosas-Acosta, Germán; Huang, Chuanshu

2011-01-01

X-linked inhibitor of apoptosis protein (XIAP) overexpression has been found to be associated with malignant cancer progression and aggression in individuals with many types of cancers. However, the molecular basis of XIAP in the regulation of cancer cell biological behavior remains largely unknown. In this study, we found that a deficiency of XIAP expression in human cancer cells by either knock-out or knockdown leads to a marked reduction in β-actin polymerization and cytoskeleton formation. Consistently, cell migration and invasion were also decreased in XIAP-deficient cells compared with parental wild-type cells. Subsequent studies demonstrated that the regulation of cell motility by XIAP depends on its interaction with the Rho GDP dissociation inhibitor (RhoGDI) via the XIAP RING domain. Furthermore, XIAP was found to negatively regulate RhoGDI SUMOylation, which might affect its activity in controlling cell motility. Collectively, our studies provide novel insights into the molecular mechanisms by which XIAP regulates cancer invasion and offer a further theoretical basis for setting XIAP as a potential prognostic marker and specific target for treatment of cancers with metastatic properties. PMID:21402697

PML nuclear bodies: regulation, function and therapeutic perspectives.

PubMed

Sahin, Umut; Lallemand-Breitenbach, Valérie; de Thé, Hugues

2014-11-01

PML nuclear bodies (NBs) were first described by electron microscopy and rediscovered through their treatment-reversible disruption in a rare leukaemia. They recruit multiple partner proteins and now emerge as interferon- and oxidative stress-responsive sumoylation factories. NBs mediate interferon-induced viral restriction, enhance proteolysis, finely tune metabolism and enforce stress-induced senescence. Apart from being markers of cellular stress, PML NBs could be harnessed pharmacologically in a number of conditions, including cancer, viral infection or neurodegenerative diseases. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Depletion of UBC9 Causes Nuclear Defects during the Vegetative and Sexual Life Cycles in Tetrahymena thermophila.

PubMed

Yang, Qianyi; Nasir, Amjad M; Coyne, Robert S; Forney, James D

2015-12-01

Ubc9p is the sole E2-conjugating enzyme for SUMOylation, and its proper function is required for regulating key nuclear events such as transcription, DNA repair, and mitosis. In Tetrahymena thermophila, the genome is separated into a diploid germ line micronucleus (MIC) that divides by mitosis and a polyploid somatic macronucleus (MAC) that divides amitotically. This unusual nuclear organization provides novel opportunities for the study of SUMOylation and Ubc9p function. We identified the UBC9 gene and demonstrated that its complete deletion from both MIC and MAC genomes is lethal. Rescue of the lethal phenotype with a GFP-UBC9 fusion gene driven by a metallothionein promoter generated a cell line with CdCl2-dependent expression of green fluorescent protein (GFP)-Ubc9p. Depletion of Ubc9p in vegetative cells resulted in the loss of MICs, but MACs continued to divide. In contrast, expression of catalytically inactive Ubc9p resulted in the accumulation of multiple MICs. Critical roles for Ubc9p were also identified during the sexual life cycle of Tetrahymena. Cell lines that were depleted for Ubc9p did not form mating pairs and therefore could not complete any of the subsequent stages of conjugation, including meiosis and macronuclear development. Mating between cells expressing catalytically inactive Ubc9p resulted in arrest during macronuclear development, consistent with our observation that Ubc9p accumulates in the developing macronucleus. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

DNA repair factor XPC is modified by SUMO-1 and ubiquitin following UV irradiation

PubMed Central

Wang, Qi-En; Zhu, Qianzheng; Wani, Gulzar; El-Mahdy, Mohamed A.; Li, Jinyou; Wani, Altaf A.

2005-01-01

Nucleotide excision repair (NER) is the major DNA repair process that removes diverse DNA lesions including UV-induced photoproducts. There are more than 20 proteins involved in NER. Among them, XPC is thought to be one of the first proteins to recognize DNA damage during global genomic repair (GGR), a sub-pathway of NER. In order to study the mechanism through which XPC participates in GGR, we investigated the possible modifications of XPC protein upon UV irradiation in mammalian cells. Western blot analysis of cell lysates from UV-irradiated normal human fibroblast, prepared by direct boiling in an SDS lysis buffer, showed several anti-XPC antibody-reactive bands with molecular weight higher than the original XPC protein. The reciprocal immunoprecipitation and siRNA transfection analysis demonstrated that XPC protein is modified by SUMO-1 and ubiquitin. By using several NER-deficient cell lines, we found that DDB2 and XPA are required for UV-induced XPC modifications. Interestingly, both the inactivation of ubiquitylation and the treatment of proteasome inhibitors quantitatively inhibited the UV-induced XPC modifications. Furthermore, XPC protein is degraded significantly following UV irradiation in XP-A cells in which sumoylation of XPC does not occur. Taken together, we conclude that XPC protein is modified by SUMO-1 and ubiquitin following UV irradiation and these modifications require the functions of DDB2 and XPA, as well as the ubiquitin–proteasome system. Our results also suggest that at least one function of UV-induced XPC sumoylation is related to the stabilization of XPC protein. PMID:16030353

Sumoylated α-skeletal muscle actin in the skeletal muscle of adult rats.

PubMed

Uda, Munehiro; Kawasaki, Hiroaki; Iizumi, Kyoichi; Shigenaga, Ayako; Baba, Takeshi; Naito, Hisashi; Yoshioka, Toshitada; Yamakura, Fumiyuki

2015-11-01

Skeletal muscles are composed of two major muscle fiber types: slow-twitch oxidative fibers and fast-twitch glycolytic fibers. The proteins in these muscle fibers are known to differ in their expression, relative abundance, and post-translational modifications. In this study, we report a previously unreported post-translational modification of α-skeletal muscle actin in the skeletal muscles of adult male F344 rats in vivo. Using two-dimensional electrophoresis (2D-PAGE), we first examined the differences in the protein expression profiles between the soleus and plantaris muscles. We found higher intensity protein spots at approximately 60 kDa and pH 9 on 2D-PAGE for the soleus muscle compared with the plantaris muscle. These spots were identified as α-skeletal muscle actin by liquid chromatography-nanoelectrospray ionization-tandem mass spectrometry and western blot analyses. In addition, we found that the 60 kDa α-skeletal muscle actin is modified by small ubiquitin-like modifier (SUMO) 1, using 2D-PAGE and western blot analyses. Furthermore, we found that α-skeletal muscle actin with larger molecular weight was localized in the nuclear and cytosol of the skeletal muscle, but not in the myofibrillar fraction by the combination of subcellular fractionation and western blot analyses. These results suggest that α-skeletal muscle actin is modified by SUMO-1 in the skeletal muscles, localized in nuclear and cytosolic fractions, and the extent of this modification is much higher in the slow muscles than in the fast muscles. This is the first study to show the presence of SUMOylated actin in animal tissues.

SUMOylation Promotes PML Degradation during Encephalomyocarditis Virus Infection▿

PubMed Central

El Mchichi, Bouchra; Regad, Tarik; Maroui, Mohamed-Ali; Rodriguez, Manuel S.; Aminev, Aleksey; Gerbaud, Sylvie; Escriou, Nicolas; Dianoux, Laurent; Chelbi-Alix, Mounira K.

2010-01-01

The promyelocytic leukemia (PML) protein is expressed in the diffuse nuclear fraction of the nucleoplasm and in matrix-associated structures, known as nuclear bodies (NBs). PML NB formation requires the covalent modification of PML to SUMO. The noncovalent interactions of SUMO with PML based on the identification of a SUMO-interacting motif within PML seem to be required for further recruitment within PML NBs of SUMOylated proteins. RNA viruses whose replication takes place in the cytoplasm and is inhibited by PML have developed various strategies to counteract the antiviral defense mediated by PML NBs. We show here that primary fibroblasts derived from PML knockout mice are more sensitive to infection with encephalomyocarditis virus (EMCV), suggesting that the absence of PML results in an increase in EMCV replication. Also, we found that EMCV induces a decrease in PML protein levels both in interferon-treated cells and in PMLIII-expressing cells. Reduction of PML was carried out by the EMCV 3C protease. Indeed, at early times postinfection, EMCV induced PML transfer from the nucleoplasm to the nuclear matrix and PML conjugation to SUMO-1, SUMO-2, and SUMO-3, leading to an increase in PML body size where the viral protease 3C and the proteasome component were found colocalizing with PML within the NBs. This process was followed by PML degradation occurring in a proteasome- and SUMO-dependent manner and did not involve the SUMO-interacting motif of PML. Together, these findings reveal a new mechanism evolved by EMCV to antagonize the PML pathway in the interferon-induced antiviral defense. PMID:20826694

The HTLV-1 oncoprotein Tax is modified by the ubiquitin related modifier 1 (Urm1).

PubMed

Hleihel, Rita; Khoshnood, Behzad; Dacklin, Ingrid; Omran, Hayssam; Mouawad, Carine; Dassouki, Zeina; El-Sabban, Marwan; Shirinian, Margret; Grabbe, Caroline; Bazarbachi, Ali

2018-04-17

Adult T-cell leukemia/lymphoma (ATL) is an aggressive malignancy secondary to chronic human T-cell lymphotropic virus 1 infection, triggered by the virally encoded oncoprotein Tax. The transforming activity and subcellular localization of Tax is strongly influenced by posttranslational modifications, among which ubiquitylation and SUMOylation have been identified as key regulators of the nuclear/cytoplasmic shuttling of Tax, as well as its ability to activate NF-κB signaling. Adding to the complex posttranslational modification landscape of Tax, we here demonstrate that Tax also interacts with the ubiquitin-related modifier 1 (Urm1). Conjugation of Urm1 to Tax results in a redistribution of Tax to the cytoplasm and major increase in the transcription of the NF-ĸB targets Rantes and interleukin-6. Utilizing a tax-transgenic Drosophila model, we show that the Urm1-dependent subcellular targeting of Tax is evolutionary conserved, and that the presence of Urm1 is strongly correlated with the transcriptional output of Diptericin, an antimicrobial peptide and established downstream target of NF-κB in flies. These data put forward Urm1 as a novel Tax modifier that modulates its oncogenic activity and hence represents a potential novel target for developing new strategies for treating ATL.

Publisher Correction: RING tetramerization is required for nuclear body biogenesis and PML sumoylation.

PubMed

Wang, Pengran; Benhenda, Shirine; Wu, Haiyan; Lallemand-Breitenbach, Valérie; Zhen, Tao; Jollivet, Florence; Peres, Laurent; Li, Yuwen; Chen, Sai-Juan; Chen, Zhu; de Thé, Hugues; Meng, Guoyu

2018-05-04

In the originally published version of this Article, the authors Sai-Juan Chen and Zhu Chen were incorrectly listed as being affiliated with 'University Paris Diderot, Sorbonne Paris Cité, INSERM U944, CNRS UMR7212, Equipe labellisée LNCC, Hôpital St. Louis 1, Paris 75475, France', and the affiliation 'Institute of Health Sciences, Shanghai Institutes for Biological Sciences and Graduate School, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai 200031, China' was inadvertently omitted. These errors have now been corrected in both the PDF and HTML versions of the Article.

PML Nuclear Bodies

PubMed Central

Lallemand-Breitenbach, Valérie; de Thé, Hugues

2010-01-01

PML nuclear bodies are matrix-associated domains that recruit an astonishing variety of seemingly unrelated proteins. Since their discovery in the early 1960s, PML bodies have fascinated cell biologists because of their beauty and their tight association with cellular disorders. The identification of PML, a gene involved in an oncogenic chromosomal translocation, as the key organizer of these domains drew instant interest onto them. The multiple levels of PML body regulation by a specific posttranslational modification, sumoylation, have raised several unsolved issues. Functionally, PML bodies may sequester, modify or degrade partner proteins, but in many ways, PML bodies still constitute an enigma. PMID:20452955

PML nuclear bodies.

PubMed

Lallemand-Breitenbach, Valérie; de Thé, Hugues

2010-05-01

PML nuclear bodies are matrix-associated domains that recruit an astonishing variety of seemingly unrelated proteins. Since their discovery in the early 1960s, PML bodies have fascinated cell biologists because of their beauty and their tight association with cellular disorders. The identification of PML, a gene involved in an oncogenic chromosomal translocation, as the key organizer of these domains drew instant interest onto them. The multiple levels of PML body regulation by a specific posttranslational modification, sumoylation, have raised several unsolved issues. Functionally, PML bodies may sequester, modify or degrade partner proteins, but in many ways, PML bodies still constitute an enigma.

Gas-Phase Enrichment of Multiply Charged Peptide Ions by Differential Ion Mobility Extend the Comprehensiveness of SUMO Proteome Analyses

NASA Astrophysics Data System (ADS)

Pfammatter, Sibylle; Bonneil, Eric; McManus, Francis P.; Thibault, Pierre

2018-04-01

The small ubiquitin-like modifier (SUMO) is a member of the family of ubiquitin-like modifiers (UBLs) and is involved in important cellular processes, including DNA damage response, meiosis and cellular trafficking. The large-scale identification of SUMO peptides in a site-specific manner is challenging not only because of the low abundance and dynamic nature of this modification, but also due to the branched structure of the corresponding peptides that further complicate their identification using conventional search engines. Here, we exploited the unusual structure of SUMO peptides to facilitate their separation by high-field asymmetric waveform ion mobility spectrometry (FAIMS) and increase the coverage of SUMO proteome analysis. Upon trypsin digestion, branched peptides contain a SUMO remnant side chain and predominantly form triply protonated ions that facilitate their gas-phase separation using FAIMS. We evaluated the mobility characteristics of synthetic SUMO peptides and further demonstrated the application of FAIMS to profile the changes in protein SUMOylation of HEK293 cells following heat shock, a condition known to affect this modification. FAIMS typically provided a 10-fold improvement of detection limit of SUMO peptides, and enabled a 36% increase in SUMO proteome coverage compared to the same LC-MS/MS analyses performed without FAIMS. [Figure not available: see fulltext.

SENP1 inhibition induces apoptosis and growth arrest of multiple myeloma cells through modulation of NF-κB signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Jun; Department of Experimental Hematology, Beijing Institute of Radiation Medicine, Beijing 100850; Sun, Hui-Yan

2015-05-01

SUMO/sentrin specific protease 1 (Senp1) is an important regulation protease in the protein sumoylation, which affects the cell cycle, proliferation and differentiation. The role of Senp1 mediated protein desumoylation in pathophysiological progression of multiple myeloma is unknown. In this study, we demonstrated that Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. Lentivirus-mediated Senp1 knockdown triggers apoptosis and reduces viability, proliferation and colony forming ability of MM cells. The NF-κB family members including P65 and inhibitor protein IkBα play important roles in regulation of MM cell survival and proliferation. We further demonstrated that Senp1 inhibition decreased IL-6-induced P65more » and IkBα phosphorylation, leading to inactivation of NF-kB signaling in MM cells. These results delineate a key role for Senp1in IL-6 induced proliferation and survival of MM cells, suggesting it may be a potential new therapeutic target in MM. - Highlights: • Senp1 is overexpressed and induced by IL-6 in multiple myeloma cells. • Senp1 knockdown triggers apoptosis and reduces proliferation of MM cells. • Senp1 inhibition decreased IL-6-induced P65 and IkBα phosphorylation.« less

Evidence for a Dual Antiviral Role of the Major Nuclear Domain 10 Component Sp100 during the Immediate-Early and Late Phases of the Human Cytomegalovirus Replication Cycle ▿

PubMed Central

Tavalai, Nina; Adler, Martina; Scherer, Myriam; Riedl, Yvonne; Stamminger, Thomas

2011-01-01

In recent studies, the nuclear domain 10 (ND10) components PML and hDaxx were identified as cellular restriction factors that inhibit the initiation of human cytomegalovirus (HCMV) replication. The antiviral function of ND10, however, is antagonized by the IE1 protein, which induces ND10 disruption. Here we show that IE1 not only de-SUMOylates PML immediately upon infection but also directly targets Sp100. IE1 expression alone was sufficient to downregulate endogenous Sp100 independently of the presence of PML. Moreover, cotransfection experiments revealed that IE1 negatively interferes with the SUMOylation of all Sp100 isoforms. The modulation of Sp100 at immediate-early (IE) times of infection, indeed, seemed to have an in vivo relevance for HCMV replication, since knockdown of Sp100 resulted in more cells initiating the viral gene expression program. In addition, we observed that Sp100 was degraded in a proteasome-dependent manner at late times postinfection, suggesting that Sp100 may play an additional antiviral role during the late phase. Infection experiments conducted with Sp100 knockdown human foreskin fibroblasts (HFFs) confirmed this hypothesis: depletion of Sp100 resulted in augmented release of progeny virus particles compared to that from control cells. Consistent with this observation, we noted increased amounts of viral late gene products in the absence of Sp100. Importantly, this elevated late gene expression was not dependent on enhanced viral IE gene expression. Taken together, our data provide evidence that Sp100 is the first ND10-related factor identified that not only possesses the potential to restrict the initial stage of infection but also inhibits HCMV replication during the late phase. PMID:21734036

SIZ1-Dependent Post-Translational Modification by SUMO Modulates Sugar Signaling and Metabolism in Arabidopsis thaliana.

PubMed

Castro, Pedro Humberto; Verde, Nuno; Lourenço, Tiago; Magalhães, Alexandre Papadopoulos; Tavares, Rui Manuel; Bejarano, Eduardo Rodríguez; Azevedo, Herlânder

2015-12-01

Post-translational modification mechanisms function as switches that mediate the balance between optimum growth and the response to environmental stimuli, by regulating the activity of key proteins. SUMO (small ubiquitin-like modifier) attachment, or sumoylation, is a post-translational modification that is essential for the plant stress response, also modulating hormonal circuits to co-ordinate developmental processes. The Arabidopsis SUMO E3 ligase SAP and Miz 1 (SIZ1) is the major SUMO conjugation enhancer in response to stress, and is implicated in several aspects of plant development. Here we report that known SUMO targets are over-represented in multiple carbohydrate-related proteins, suggesting a functional link between sumoylation and sugar metabolism and signaling in plants. We subsequently observed that SUMO-conjugated proteins accumulate in response to high doses of sugar in a SIZ1-dependent manner, and that the null siz1 mutant displays increased expression of sucrose and starch catabolic genes and shows reduced starch levels. We demonstrated that SIZ1 controls germination time and post-germination growth via osmotic and sugar-dependent signaling, respectively. Glucose was specifically linked to SUMO-sugar interplay, with high levels inducing root growth inhibition and aberrant root hair morphology in siz1. The use of sugar analogs and sugar marker gene expression analysis allowed us to implicate SIZ1 in a signaling pathway dependent on glucose metabolism, probably involving modulation of SNF1-related kinase 1 (SnRK1) activity. © The Author 2015. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Evolution of SUMO Function and Chain Formation in Insects.

PubMed

Ureña, Enric; Pirone, Lucia; Chafino, Silvia; Pérez, Coralia; Sutherland, James D; Lang, Valérie; Rodriguez, Manuel S; Lopitz-Otsoa, Fernando; Blanco, Francisco J; Barrio, Rosa; Martín, David

2016-02-01

SUMOylation, the covalent binding of Small Ubiquitin-like Modifier (SUMO) to target proteins, is a posttranslational modification that regulates critical cellular processes in eukaryotes. In insects, SUMOylation has been studied in holometabolous species, particularly in the dipteran Drosophila melanogaster, which contains a single SUMO gene (smt3). This has led to the assumption that insects contain a single SUMO gene. However, the analysis of insect genomes shows that basal insects contain two SUMO genes, orthologous to vertebrate SUMO1 and SUMO2/3. Our phylogenetical analysis reveals that the SUMO gene has been duplicated giving rise to SUMO1 and SUMO2/3 families early in Metazoan evolution, and that later in insect evolution the SUMO1 gene has been lost after the Hymenoptera divergence. To explore the consequences of this loss, we have examined the characteristics and different biological functions of the two SUMO genes (SUMO1 and SUMO3) in the hemimetabolous cockroach Blattella germanica and compared them with those of Drosophila Smt3. Here, we show that the metamorphic role of the SUMO genes is evolutionary conserved in insects, although there has been a regulatory switch from SUMO1 in basal insects to SUMO3 in more derived ones. We also show that, unlike vertebrates, insect SUMO3 proteins cannot form polySUMO chains due to the loss of critical lysine residues within the N-terminal part of the protein. Furthermore, the formation of polySUMO chains by expression of ectopic human SUMO3 has a deleterious effect in Drosophila. These findings contribute to the understanding of the functional consequences of the evolution of SUMO genes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Effects of arsenic on modification of promyelocytic leukemia (PML): PML responds to low levels of arsenite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirano, Seishiro, E-mail: seishiro@nies.go.jp; Graduate School of Pharmaceutical Sciences, Chiba University; Watanabe, Takayuki

2013-12-15

Inorganic arsenite (iAs{sup 3+}) is a two-edged sword. iAs{sup 3+} is a well-known human carcinogen; nevertheless, it has been used as a therapeutic drug for acute promyelocytic leukemia (APL), which is caused by a fusion protein comprising retinoic acid receptor-α and promyelocytic leukemia (PML). PML, a nuclear transcription factor, has a RING finger domain with densely positioned cysteine residues. To examine PML-modulated cellular responses to iAs{sup 3+}, CHO-K1 and HEK293 cells were each used to establish cell lines that expressed ectopic human PML. Overexpression of PML increased susceptibility to iAs{sup 3+} in CHO-K1 cells, but not in HEK293 cells. Exposuremore » of PML-transfected cells to iAs{sup 3+} caused PML to change from a soluble form to less soluble forms, and this modification of PML was observable even with just 0.1 μM iAs{sup 3+} (7.5 ppb). Western blot and immunofluorescent microscopic analyses revealed that the biochemical changes of PML were caused at least in part by conjugation with small ubiquitin-like modifier proteins (SUMOylation). A luciferase reporter gene was used to investigate whether modification of PML was caused by oxidative stress or activation of antioxidant response element (ARE) in CHO-K1 cells. Modification of PML protein occurred faster than activation of the ARE in response to iAs{sup 3+}, suggesting that PML was not modified as a consequence of oxidative stress-induced ARE activation. - Highlights: • PML was found in nuclear microspecles in response to arsenite. • Arsenite triggers SUMOylation of PML. • Arsenite modifies PML at as low as 0.1 μM. • Modification of PML is not caused by ARE activation.« less

Variants of Transient Receptor Potential Melastatin Member 4 in Childhood Atrioventricular Block.

PubMed

Syam, Ninda; Chatel, Stéphanie; Ozhathil, Lijo Cherian; Sottas, Valentin; Rougier, Jean-Sébastien; Baruteau, Alban; Baron, Estelle; Amarouch, Mohamed-Yassine; Daumy, Xavier; Probst, Vincent; Schott, Jean-Jacques; Abriel, Hugues

2016-05-20

Transient receptor potential melastatin member 4 (TRPM4) is a nonselective cation channel. TRPM4 mutations have been linked to cardiac conduction disease and Brugada syndrome. The mechanisms underlying TRPM4-dependent conduction slowing are not fully understood. The aim of this study was to characterize TRPM4 genetic variants found in patients with congenital or childhood atrioventricular block. Ninety-one patients with congenital or childhood atrioventricular block were screened for candidate genes. Five rare TRPM4 genetic variants were identified and investigated. The variants were expressed heterologously in HEK293 cells. Two of the variants, A432T and A432T/G582S, showed decreased expression of the protein at the cell membrane; inversely, the G582S variant showed increased expression. Further functional characterization of these variants using whole-cell patch-clamp configuration showed a loss of function and a gain of function, respectively. We hypothesized that the observed decrease in expression was caused by a folding and trafficking defect. This was supported by the observation that incubation of these variants at lower temperature partially rescued their expression and function. Previous studies have suggested that altered SUMOylation of TRPM4 may cause a gain of function; however, we did not find any evidence that supports SUMOylation as being directly involved for the gain-of-function variant. This study underpins the role of TRPM4 in the cardiac conduction system. The loss-of-function variants A432T/G582S found in 2 unrelated patients with atrioventricular block are most likely caused by misfolding-dependent altered trafficking. The ability to rescue this variant with lower temperature may provide a novel use of pharmacological chaperones in treatment strategies. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

The PTEN protein: cellular localization and post-translational regulation.

PubMed

Leslie, Nick R; Kriplani, Nisha; Hermida, Miguel A; Alvarez-Garcia, Virginia; Wise, Helen M

2016-02-01

The phosphatase and tensin homologue deleted on chromosome 10 (PTEN) phosphatase dephosphorylates PIP3, the lipid product of the class I PI 3-kinases, and suppresses the growth and proliferation of many cell types. It has been heavily studied, in large part due to its status as a tumour suppressor, the loss of function of which is observed through diverse mechanisms in many tumour types. Here we present a concise review of our understanding of the PTEN protein and highlight recent advances, particularly in our understanding of its localization and regulation by ubiquitination and SUMOylation. © 2016 Authors; published by Portland Press Limited.

Function of YY1 in Long-Distance DNA Interactions

PubMed Central

Atchison, Michael L.

2014-01-01

During B cell development, long-distance DNA interactions are needed for V(D)J somatic rearrangement of the immunoglobulin (Ig) loci to produce functional Ig genes, and for class switch recombination (CSR) needed for antibody maturation. The tissue-specificity and developmental timing of these mechanisms is a subject of active investigation. A small number of factors are implicated in controlling Ig locus long-distance interactions including Pax5, Yin Yang 1 (YY1), EZH2, IKAROS, CTCF, cohesin, and condensin proteins. Here we will focus on the role of YY1 in controlling these mechanisms. YY1 is a multifunctional transcription factor involved in transcriptional activation and repression, X chromosome inactivation, Polycomb Group (PcG) protein DNA recruitment, and recruitment of proteins required for epigenetic modifications (acetylation, deacetylation, methylation, ubiquitination, sumoylation, etc.). YY1 conditional knock-out indicated that YY1 is required for B cell development, at least in part, by controlling long-distance DNA interactions at the immunoglobulin heavy chain and Igκ loci. Our recent data show that YY1 is also required for CSR. The mechanisms implicated in YY1 control of long-distance DNA interactions include controlling non-coding antisense RNA transcripts, recruitment of PcG proteins to DNA, and interaction with complexes involved in long-distance DNA interactions including the cohesin and condensin complexes. Though common rearrangement mechanisms operate at all Ig loci, their distinct temporal activation along with the ubiquitous nature of YY1 poses challenges for determining the specific mechanisms of YY1 function in these processes, and their regulation at the tissue-specific and B cell stage-specific level. The large numbers of post-translational modifications that control YY1 functions are possible candidates for regulation. PMID:24575094

TRIM25 enhances cell growth and cell survival by modulating p53 signals via interaction with G3BP2 in prostate cancer.

PubMed

Takayama, Ken-Ichi; Suzuki, Takashi; Tanaka, Tomoaki; Fujimura, Tetsuya; Takahashi, Satoru; Urano, Tomohiko; Ikeda, Kazuhiro; Inoue, Satoshi

2018-04-01

Prostate cancer growth is promoted by the gene regulatory action of androgen receptor (AR) and its downstream signals. The aberrant dysfunction of tumor suppressor p53 has an important role in the prognosis of cancer. We previously found that androgen treatments translocate p53 to the cytoplasm. The mechanism of this translocation depends on sumoylation of p53 by complex of SUMO E3 ligase RanBP2 with androgen-induced GTPase-activating protein-binding protein 2 (G3BP2). Here, we identified tripartite motif-containing protein 25 (TRIM25)/estrogen-responsive finger protein (Efp) as a novel interacting partner of G3BP2 protein complex. Then, we demonstrated that TRIM25 knockdown resulted in p53 downstream activation for cell cycle inhibition and apoptosis induction in LNCaP and 22Rv1 cells. In contrast, overexpression of TRIM25 promoted prostate cancer cell proliferation and inhibited apoptosis by docetaxel treatment in LNCaP cells. We observed that p53 activity was reduced by mechanism of G3BP2-mediated nuclear export in TRIM25-overexpressing prostate cancer cells. We also found TRIM25 is important for G3BP2/RanBP2-mediated p53 modification. Clinically, we newly demonstrated that TRIM25 is a prognostic factor for prostate cancer patients. Expression of TRIM25 is significantly associated with cytoplasmic p53 expression and G3BP2. Moreover, TRIM25 knockdown results in reduced tumor growth and increased p53 activity in the mouse xenograft model of prostate cancer. Thus, our findings show that overexpression of TRIM25 promoted prostate cancer cell proliferation and cell survival by modulating p53 nuclear export mechanism with G3BP2 interaction.

SUMO regulates p21Cip1 intracellular distribution and with p21Cip1 facilitates multiprotein complex formation in the nucleolus upon DNA damage.

PubMed

Brun, Sonia; Abella, Neus; Berciano, Maria T; Tapia, Olga; Jaumot, Montserrat; Freire, Raimundo; Lafarga, Miguel; Agell, Neus

2017-01-01

We previously showed that p21Cip1 transits through the nucleolus on its way from the nucleus to the cytoplasm and that DNA damage inhibits this transit and induces the formation of p21Cip1-containing intranucleolar bodies (INoBs). Here, we demonstrate that these INoBs also contain SUMO-1 and UBC9, the E2 SUMO-conjugating enzyme. Furthermore, whereas wild type SUMO-1 localized in INoBs, a SUMO-1 mutant, which is unable to conjugate with proteins, does not, suggesting the presence of SUMOylated proteins at INoBs. Moreover, depletion of the SUMO-conjugating enzyme UBC9 or the sumo hydrolase SENP2 changed p21Cip1 intracellular distribution. In addition to SUMO-1 and p21Cip1, cell cycle regulators and DNA damage checkpoint proteins, including Cdk2, Cyclin E, PCNA, p53 and Mdm2, and PML were also detected in INoBs. Importantly, depletion of UBC9 or p21Cip1 impacted INoB biogenesis and the nucleolar accumulation of the cell cycle regulators and DNA damage checkpoint proteins following DNA damage. The impact of p21Cip1 and SUMO-1 on the accumulation of proteins in INoBs extends also to CRM1, a nuclear exportin that is also important for protein translocation from the cytoplasm to the nucleolus. Thus, SUMO and p21Cip1 regulate the transit of proteins through the nucleolus, and that disruption of nucleolar export by DNA damage induces SUMO and p21Cip1 to act as hub proteins to form a multiprotein complex in the nucleolus.

SUMO regulates p21Cip1 intracellular distribution and with p21Cip1 facilitates multiprotein complex formation in the nucleolus upon DNA damage

PubMed Central

Brun, Sonia; Abella, Neus; Berciano, Maria T.; Tapia, Olga; Jaumot, Montserrat; Freire, Raimundo; Lafarga, Miguel

2017-01-01

We previously showed that p21Cip1 transits through the nucleolus on its way from the nucleus to the cytoplasm and that DNA damage inhibits this transit and induces the formation of p21Cip1-containing intranucleolar bodies (INoBs). Here, we demonstrate that these INoBs also contain SUMO-1 and UBC9, the E2 SUMO-conjugating enzyme. Furthermore, whereas wild type SUMO-1 localized in INoBs, a SUMO-1 mutant, which is unable to conjugate with proteins, does not, suggesting the presence of SUMOylated proteins at INoBs. Moreover, depletion of the SUMO-conjugating enzyme UBC9 or the sumo hydrolase SENP2 changed p21Cip1 intracellular distribution. In addition to SUMO-1 and p21Cip1, cell cycle regulators and DNA damage checkpoint proteins, including Cdk2, Cyclin E, PCNA, p53 and Mdm2, and PML were also detected in INoBs. Importantly, depletion of UBC9 or p21Cip1 impacted INoB biogenesis and the nucleolar accumulation of the cell cycle regulators and DNA damage checkpoint proteins following DNA damage. The impact of p21Cip1 and SUMO-1 on the accumulation of proteins in INoBs extends also to CRM1, a nuclear exportin that is also important for protein translocation from the cytoplasm to the nucleolus. Thus, SUMO and p21Cip1 regulate the transit of proteins through the nucleolus, and that disruption of nucleolar export by DNA damage induces SUMO and p21Cip1 to act as hub proteins to form a multiprotein complex in the nucleolus. PMID:28582471

Peptide affinity analysis of proteins that bind to an unstructured NH2-terminal region of the osmoprotective transcription factor NFAT5

PubMed Central

DuMond, Jenna F.; Ramkissoon, Kevin; Zhang, Xue; Izumi, Yuichiro; Wang, Xujing; Eguchi, Koji; Gao, Shouguo; Mukoyama, Masashi; Ferraris, Joan D.

2016-01-01

NFAT5 is an osmoregulated transcription factor that particularly increases expression of genes involved in protection against hypertonicity. Transcription factors often contain unstructured regions that bind co-regulatory proteins that are crucial for their function. The NH2-terminal region of NFAT5 contains regions predicted to be intrinsically disordered. We used peptide aptamer-based affinity chromatography coupled with mass spectrometry to identify protein preys pulled down by one or more overlapping 20 amino acid peptide baits within a predicted NH2-terminal unstructured region of NFAT5. We identify a total of 467 unique protein preys that associate with at least one NH2-terminal peptide bait from NFAT5 in either cytoplasmic or nuclear extracts from HEK293 cells treated with elevated, normal, or reduced NaCl concentrations. Different sets of proteins are pulled down from nuclear vs. cytoplasmic extracts. We used GeneCards to ascertain known functions of the protein preys. The protein preys include many that were previously known, but also many novel ones. Consideration of the novel ones suggests many aspects of NFAT5 regulation, interaction and function that were not previously appreciated, for example, hypertonicity inhibits NFAT5 by sumoylating it and the NFAT5 protein preys include components of the CHTOP complex that desumoylate proteins, an action that should contribute to activation of NFAT5. PMID:26757802

Identification and detoxification of glycolaldehyde, an unattended bioethanol fermentation inhibitor.

PubMed

Jayakody, Lahiru N; Ferdouse, Jannatul; Hayashi, Nobuyuki; Kitagaki, Hiroshi

2017-03-01

Although there have been approximately 60 chemical compounds identified as potent fermentation inhibitors in lignocellulose hydrolysate, our research group recently discovered glycolaldehyde as a key fermentation inhibitor during second generation biofuel production. Accordingly, we have developed a yeast S. cerevisiae strain exhibiting tolerance to glycolaldehyde. During this glycolaldehyde study, we established novel approaches for rational engineering of inhibitor-tolerant S. cerevisiae strains, including engineering redox cofactors and engineering the SUMOylation pathway. These new technical dimensions provide a novel platform for engineering S. cerevisiae strains to overcome one of the key barriers for industrialization of lignocellulosic ethanol production. As such, this review discusses novel biochemical insight of glycolaldehyde in the context of the biofuel industry.

From an old remedy to a magic bullet: molecular mechanisms underlying the therapeutic effects of arsenic in fighting leukemia

PubMed Central

Zhou, Guang-Biao; Zhang, Xiao-Wei; Mao, Jian-Hua; de Thé, Hugues

2011-01-01

Arsenic had been used in treating malignancies from the 18th to mid-20th century. In the past 3 decades, arsenic was revived and shown to be able to induce complete remission and to achieve, when combined with all-trans retinoic acid and chemotherapy, a 5-year overall survival of 90% in patients with acute promyelocytic leukemia driven by the t(15;17) translocation-generated promyelocytic leukemia–retinoic acid receptor α (PML-RARα) fusion. Molecularly, arsenic binds thiol residues and induces the formation of reactive oxygen species, thus affecting numerous signaling pathways. Interestingly, arsenic directly binds the C3HC4 zinc finger motif in the RBCC domain of PML and PML-RARα, induces their homodimerization and multimerization, and enhances their interaction with the SUMO E2 conjugase Ubc9, facilitating subsequent sumoylation/ubiquitination and proteasomal degradation. Arsenic-caused intermolecular disulfide formation in PML also contributes to PML-multimerization. All-trans retinoic acid, which targets PML-RARα for degradation through its RARα moiety, synergizes with arsenic in eliminating leukemia-initiating cells. Arsenic perturbs a number of proteins involved in other hematologic malignancies, including chronic myeloid leukemia and adult T-cell leukemia/lymphoma, whereby it may bring new therapeutic benefits. The successful revival of arsenic in acute promyelocytic leukemia, together with modern mechanistic studies, has thus allowed a new paradigm to emerge in translational medicine. PMID:21422471

Regulation of Stress-Inducible Phosphoprotein 1 Nuclear Retention by Protein Inhibitor of Activated STAT PIAS1

PubMed Central

Soares, Iaci N.; Caetano, Fabiana A.; Pinder, Jordan; Rodrigues, Bruna Roz; Beraldo, Flavio H.; Ostapchenko, Valeriy G.; Durette, Chantal; Pereira, Grace Schenatto; Lopes, Marilene H.; Queiroz-Hazarbassanov, Nicolle; Cunha, Isabela W.; Sanematsu, Paulo I.; Suzuki, Sergio; Bleggi-Torres, Luiz F.; Schild-Poulter, Caroline; Thibault, Pierre; Dellaire, Graham; Martins, Vilma R.; Prado, Vania F.; Prado, Marco A. M.

2013-01-01

Stress-inducible phosphoprotein 1 (STI1), a cochaperone for Hsp90, has been shown to regulate multiple pathways in astrocytes, but its contributions to cellular stress responses are not fully understood. We show that in response to irradiation-mediated DNA damage stress STI1 accumulates in the nucleus of astrocytes. Also, STI1 haploinsufficiency decreases astrocyte survival after irradiation. Using yeast two-hybrid screenings we identified several nuclear proteins as STI1 interactors. Overexpression of one of these interactors, PIAS1, seems to be specifically involved in STI1 nuclear retention and in directing STI1 and Hsp90 to specific sub-nuclear regions. PIAS1 and STI1 co-immunoprecipitate and PIAS1 can function as an E3 SUMO ligase for STI. Using mass spectrometry we identified five SUMOylation sites in STI1. A STI1 mutant lacking these five sites is not SUMOylated, but still accumulates in the nucleus in response to increased expression of PIAS1, suggesting the possibility that a direct interaction with PIAS1 could be responsible for STI1 nuclear retention. To test this possibility, we mapped the interaction sites between PIAS1 and STI1 using yeast-two hybrid assays and surface plasmon resonance and found that a large domain in the N-terminal region of STI1 interacts with high affinity with amino acids 450–480 of PIAS1. Knockdown of PIAS1 in astrocytes impairs the accumulation of nuclear STI1 in response to irradiation. Moreover, a PIAS1 mutant lacking the STI1 binding site is unable to increase STI1 nuclear retention. Interestingly, in human glioblastoma multiforme PIAS1 expression is increased and we found a significant correlation between increased PIAS1 expression and STI1 nuclear localization. These experiments provide evidence that direct interaction between STI1 and PIAS1 is involved in the accumulation of nuclear STI1. This retention mechanism could facilitate nuclear chaperone activity. PMID:23938469

Nebulized hyaluronan ameliorates lung inflammation in cystic fibrosis mice.

PubMed

Gavina, Manuela; Luciani, Alessandro; Villella, Valeria R; Esposito, Speranza; Ferrari, Eleonora; Bressani, Ilaria; Casale, Alida; Bruscia, Emanuela M; Maiuri, Luigi; Raia, Valeria

2013-08-01

Chronic lung inflammation with increased susceptibility to bacterial infections cause much of the morbidity and mortality in patients with cystic fibrosis (CF), the most common severe, autosomal recessively inherited disease in the Caucasian population. Exogenous inhaled hyaluronan (HA) can exert a protective effect against injury and beneficial effects of HA have been shown in experimental models of chronic respiratory diseases. Our objective was to examine whether exogenous administration of nebulized HA might interfere with lung inflammation in CF. F508del homozygous mice (Cftr(F508del) ) and transgenic mice overexpressing the ENaC channel β-subunit (Scnn1b-Tg) were treated with nebulized HA (0.5 mg/mouse/day for 7 days). Tumor necrosis factor-alpha (TNFα), macrophage inflammatory protein-2 (MIP-2), myeloperoxidase (MPO) levels, and macrophage infiltration were assessed on lung tissues. IB3-1 and CFBE41o-epithelial cell lines were cultured with HA (24 hr, 100 µg/ml) and Reactive Oxygen Species (ROS), Tissue Transglutaminase (TG2) SUMOylation and Peroxisome Proliferator Activated Receptor gamma (PPARγ) and phospho-p42/p44 levels were measured by dichlorodihydrofluorescein assay, or fluorescence resonance energy transfer (FRET) microscopy or immunoblots. Nebulized HA reduced TNFα expression (P < 0.005); TNFα, MIP-2, and MPO protein levels (P < 0.05); MPO activity (P < 0.05); and CD68+ cells counts (P < 0.005) in lung tissues of Cftr(F508del) and Scnn1b-Tg mice, compared with saline-treated mice. HA reduced ROS, TG2 SUMOylation, TG2 activity, phospho-p42-44, and increased PPARγ protein in both IB3-1 and CFBE41o cells (P < 0.05). Nebulized HA is effective in controlling inflammation in vivo in mice CF airways and in vitro in human airway epithelial cells. We provide the proof of concept for the use of inhaled HA as a potential anti-inflammatory drug in CF therapy. Copyright © 2012 Wiley Periodicals, Inc.

The homeodomain-interacting protein kinase HPK-1 preserves protein homeostasis and longevity through master regulatory control of the HSF-1 chaperone network and TORC1-restricted autophagy in Caenorhabditis elegans

PubMed Central

Morton, Elizabeth A.; Cornwell, Adam B.; Crick, Beresford; Lamitina, Todd; Douglas, Peter M.

2017-01-01

An extensive proteostatic network comprised of molecular chaperones and protein clearance mechanisms functions collectively to preserve the integrity and resiliency of the proteome. The efficacy of this network deteriorates during aging, coinciding with many clinical manifestations, including protein aggregation diseases of the nervous system. A decline in proteostasis can be delayed through the activation of cytoprotective transcriptional responses, which are sensitive to environmental stress and internal metabolic and physiological cues. The homeodomain-interacting protein kinase (hipk) family members are conserved transcriptional co-factors that have been implicated in both genotoxic and metabolic stress responses from yeast to mammals. We demonstrate that constitutive expression of the sole Caenorhabditis elegans Hipk homolog, hpk-1, is sufficient to delay aging, preserve proteostasis, and promote stress resistance, while loss of hpk-1 is deleterious to these phenotypes. We show that HPK-1 preserves proteostasis and extends longevity through distinct but complementary genetic pathways defined by the heat shock transcription factor (HSF-1), and the target of rapamycin complex 1 (TORC1). We demonstrate that HPK-1 antagonizes sumoylation of HSF-1, a post-translational modification associated with reduced transcriptional activity in mammals. We show that inhibition of sumoylation by RNAi enhances HSF-1-dependent transcriptional induction of chaperones in response to heat shock. We find that hpk-1 is required for HSF-1 to induce molecular chaperones after thermal stress and enhances hormetic extension of longevity. We also show that HPK-1 is required in conjunction with HSF-1 for maintenance of proteostasis in the absence of thermal stress, protecting against the formation of polyglutamine (Q35::YFP) protein aggregates and associated locomotory toxicity. These functions of HPK-1/HSF-1 undergo rapid down-regulation once animals reach reproductive maturity. We show that HPK-1 fortifies proteostasis and extends longevity by an additional independent mechanism: induction of autophagy. HPK-1 is necessary for induction of autophagosome formation and autophagy gene expression in response to dietary restriction (DR) or inactivation of TORC1. The autophagy-stimulating transcription factors pha-4/FoxA and mxl-2/Mlx, but not hlh-30/TFEB or the nuclear hormone receptor nhr-62, are necessary for extended longevity resulting from HPK-1 overexpression. HPK-1 expression is itself induced by transcriptional mechanisms after nutritional stress, and post-transcriptional mechanisms in response to thermal stress. Collectively our results position HPK-1 at a central regulatory node upstream of the greater proteostatic network, acting at the transcriptional level by promoting protein folding via chaperone expression, and protein turnover via expression of autophagy genes. HPK-1 therefore provides a promising intervention point for pharmacological agents targeting the protein homeostasis system as a means of preserving robust longevity. PMID:29036198

Histone phosphorylation: its role during cell cycle and centromere identity in plants.

PubMed

Zhang, B; Dong, Q; Su, H; Birchler, J A; Han, F

2014-01-01

As the main protein components of chromatin, histones can alter the structural/functional capabilities of chromatin by undergoing extensive post-translational modifications (PTMs) such as phosphorylation, methylation, acetylation, ubiquitination, sumoylation, and so on. These PTMs are thought to transmit signals from the chromatin to the cell machinery to regulate various processes. Histone phosphorylation is associated with chromosome condensation/segregation, activation of transcription, and DNA damage repair. In this review, we focus on how different histone phosphorylations mark for chromatin change during the cell cycle, the relationship between histone phosphorylation and functional centromeres, and the candidate kinases that trigger and the phosphatase or kinase inhibitors that alter histone phosphorylation. Finally, we review the crosstalk between different PTMs. © 2014 S. Karger AG, Basel.

Structure of metabotropic glutamate receptor C-terminal domains in contact with interacting proteins.

PubMed

Enz, Ralf

2012-01-01

Metabotropic glutamate receptors (mGluRs) regulate intracellular signal pathways that control several physiological tasks, including neuronal excitability, learning, and memory. This is achieved by the formation of synaptic signal complexes, in which mGluRs assemble with functionally related proteins such as enzymes, scaffolds, and cytoskeletal anchor proteins. Thus, mGluR associated proteins actively participate in the regulation of glutamatergic neurotransmission. Importantly, dysfunction of mGluRs and interacting proteins may lead to impaired signal transduction and finally result in neurological disorders, e.g., night blindness, addiction, epilepsy, schizophrenia, autism spectrum disorders and Parkinson's disease. In contrast to solved crystal structures of extracellular N-terminal domains of some mGluR types, only a few studies analyzed the conformation of intracellular receptor domains. Intracellular C-termini of most mGluR types are subject to alternative splicing and can be further modified by phosphorylation and SUMOylation. In this way, diverse interaction sites for intracellular proteins that bind to and regulate the glutamate receptors are generated. Indeed, most of the known mGluR binding partners interact with the receptors' C-terminal domains. Within the last years, different laboratories analyzed the structure of these domains and described the geometry of the contact surface between mGluR C-termini and interacting proteins. Here, I will review recent progress in the structure characterization of mGluR C-termini and provide an up-to-date summary of the geometry of these domains in contact with binding partners.

Chromatin-Bound IκBα Regulates a Subset of Polycomb Target Genes in Differentiation and Cancer

PubMed Central

Mulero, María Carmen; Ferres-Marco, Dolors; Islam, Abul; Margalef, Pol; Pecoraro, Matteo; Toll, Agustí; Drechsel, Nils; Charneco, Cristina; Davis, Shelly; Bellora, Nicolás; Gallardo, Fernando; López-Arribillaga, Erika; Asensio-Juan, Elena; Rodilla, Verónica; González, Jessica; Iglesias, Mar; Shih, Vincent; Albà, M. Mar; Di Croce, Luciano; Hoffmann, Alexander; Miyamoto, Shigeki; Villà-Freixa, Jordi; López-Bigas, Nuria; Keyes, William M.; Domínguez, María; Bigas, Anna; Espinosa, Lluís

2014-01-01

Summary IκB proteins are the primary inhibitors of NF-κB. Here, we demonstrate that sumoylated and phosphorylated IκBα accumulates in the nucleus of keratinocytes and interacts with histones H2A and H4 at the regulatory region of HOX and IRX genes. Chromatin-bound IκBα modulates Polycomb recruitment and imparts their competence to be activated by TNFα. Mutations in the Drosophila IκBα gene cactus enhance the homeotic phenotype of Polycomb mutants, which is not counteracted by mutations in dorsal/NF-κB. Oncogenic transformation of keratinocytes results in cytoplasmic IκBα translocation associated with a massive activation of Hox. Accumulation of cytoplasmic IκBα was found in squamous cell carcinoma (SCC) associated with IKK activation and HOX upregulation. PMID:23850221

A SUMO and ubiquitin code coordinates protein traffic at replication factories.

PubMed

Lecona, Emilio; Fernandez-Capetillo, Oscar

2016-12-01

Post-translational modifications regulate each step of DNA replication to ensure the faithful transmission of genetic information. In this context, we recently showed that deubiquitination of SUMO2/3 and SUMOylated proteins by USP7 helps to create a SUMO-rich and ubiquitin-low environment around replisomes that is necessary to maintain the activity of replication forks and for new origin firing. We propose that a two-flag system mediates the collective concentration of factors at sites of DNA replication, whereby SUMO and Ubiquitinated-SUMO would constitute "stay" or "go" signals respectively for replisome and accessory factors. We here discuss the findings that led to this model, which have implications for the potential use of USP7 inhibitors as anticancer agents. © 2016 WILEY Periodicals, Inc.

Nuclear pool of phosphatidylinositol 4 phosphate 5 kinase 1α is modified by polySUMO-2 during apoptosis.

PubMed

Chakrabarti, Rajarshi; Bhowmick, Debajit; Bhargava, Varsha; Bhar, Kaushik; Siddhanta, Anirban

2013-09-20

Phosphatidylinositol 4 phosphate 5 kinase 1α (PIP5K) is mainly localized in the cytosol and plasma membrane. Studies have also indicated its prominent association with nuclear speckles. The exact nature of this nuclear pool of PIP5K is not clear. Using biochemical and microscopic techniques, we have demonstrated that the nuclear pool of PIP5K is modified by SUMO-1 in HEK-293 cells stably expressing PIP5K. Moreover, this SUMOylated pool of PIP5K increased during apoptosis. PolySUMO-2 chain conjugated PIP5K was detected by pull-down experiment using affinity-tagged RNF4, a polySUMO-2 binding protein, during late apoptosis. Copyright © 2013 Elsevier Inc. All rights reserved.

Dad's Snoring May Have Left Molecular Scars in Your DNA: the Emerging Role of Epigenetics in Sleep Disorders.

PubMed

Morales-Lara, Daniela; De-la-Peña, Clelia; Murillo-Rodríguez, Eric

2018-04-01

The sleep-wake cycle is a biological phenomena under the orchestration of neurophysiological, neurochemical, neuroanatomical, and genetical mechanisms. Moreover, homeostatic and circadian processes participate in the regulation of sleep across the light-dark period. Further complexity of the understanding of the genesis of sleep engages disturbances which have been characterized and classified in a variety of sleep-wake cycle disorders. The most prominent sleep alterations include insomnia as well as excessive daytime sleepiness. On the other side, several human diseases have been linked with direct changes in DNA, such as chromatin configuration, genomic imprinting, DNA methylation, histone modifications (acetylation, methylation, ubiquitylation or sumoylation, etc.), and activating RNA molecules that are transcribed from DNA but not translated into proteins. Epigenetic theories primarily emphasize the interaction between the environment and gene expression. According to these approaches, the environment to which mammals are exposed has a significant role in determining the epigenetic modifications occurring in chromosomes that ultimately would influence not only development but also the descendants' physiology and behavior. Thus, what makes epigenetics intriguing is that, unlike genetic variation, modifications in DNA are altered directly by the environment and, in some cases, these epigenetic changes may be inherited by future generations. Thus, it is likely that epigenetic phenomena might contribute to the homeostatic and/or circadian control of sleep and, possibly, have an undescribed link with sleep disorders. An exciting new horizon of research is arising between sleep and epigenetics since it represents the relevance of the study of how the genome learns from its experiences and modulates behavior, including sleep.

Chromatin-bound IκBα regulates a subset of polycomb target genes in differentiation and cancer.

PubMed

Mulero, María Carmen; Ferres-Marco, Dolors; Islam, Abul; Margalef, Pol; Pecoraro, Matteo; Toll, Agustí; Drechsel, Nils; Charneco, Cristina; Davis, Shelly; Bellora, Nicolás; Gallardo, Fernando; López-Arribillaga, Erika; Asensio-Juan, Elena; Rodilla, Verónica; González, Jessica; Iglesias, Mar; Shih, Vincent; Mar Albà, M; Di Croce, Luciano; Hoffmann, Alexander; Miyamoto, Shigeki; Villà-Freixa, Jordi; López-Bigas, Nuria; Keyes, William M; Domínguez, María; Bigas, Anna; Espinosa, Lluís

2013-08-12

IκB proteins are the primary inhibitors of NF-κB. Here, we demonstrate that sumoylated and phosphorylated IκBα accumulates in the nucleus of keratinocytes and interacts with histones H2A and H4 at the regulatory region of HOX and IRX genes. Chromatin-bound IκBα modulates Polycomb recruitment and imparts their competence to be activated by TNFα. Mutations in the Drosophila IκBα gene cactus enhance the homeotic phenotype of Polycomb mutants, which is not counteracted by mutations in dorsal/NF-κB. Oncogenic transformation of keratinocytes results in cytoplasmic IκBα translocation associated with a massive activation of Hox. Accumulation of cytoplasmic IκBα was found in squamous cell carcinoma (SCC) associated with IKK activation and HOX upregulation. Copyright © 2013 Elsevier Inc. All rights reserved.

Conjecture Regarding Posttranslational Modifications to the Arabidopsis Type I Proton-Pumping Pyrophosphatase (AVP1)

PubMed Central

Pizzio, Gaston A.; Hirschi, Kendal D.; Gaxiola, Roberto A.

2017-01-01

Agbiotechnology uses genetic engineering to improve the output and value of crops. Altering the expression of the plant Type I Proton-pumping Pyrophosphatase (H+-PPase) has already proven to be a useful tool to enhance crop productivity. Despite the effective use of this gene in translational research, information regarding the intracellular localization and functional plasticity of the pump remain largely enigmatic. Using computer modeling several putative phosphorylation, ubiquitination and sumoylation target sites were identified that may regulate Arabidopsis H+-PPase (AVP1- Arabidopsis Vacuolar Proton-pump 1) subcellular trafficking and activity. These putative regulatory sites will direct future research that specifically addresses the partitioning and transport characteristics of this pump. We posit that fine-tuning H+-PPases activity and cellular distribution will facilitate rationale strategies for further genetic improvements in crop productivity. PMID:28955362

The cold-induced basic helix-loop-helix transcription factor gene MdCIbHLH1 encodes an ICE-like protein in apple

PubMed Central

2012-01-01

Background Plant growth is greatly affected by low temperatures, and the expression of a number of genes is induced by cold stress. Although many genes in the cold signaling pathway have been identified in Arabidopsis, little is known about the transcription factors involved in the cold stress response in apple. Results Here, we show that the apple bHLH (basic helix-loop-helix) gene MdCIbHLH1 (Cold-Induced bHLH1), which encodes an ICE-like protein, was noticeably induced in response to cold stress. The MdCIbHLH1 protein specifically bound to the MYC recognition sequences in the AtCBF3 promoter, and MdCIbHLH1 overexpression enhanced cold tolerance in transgenic Arabidopsis. In addition, the MdCIbHLH1 protein bound to the promoters of MdCBF2 and favorably contributed to cold tolerance in transgenic apple plants by upregulating the expression of MdCBF2 through the CBF (C-repeat-binding factor) pathway. Our findings indicate that MdCIbHLH1 functions in stress tolerance in different species. For example, ectopic MdCIbHLH1 expression conferred enhanced chilling tolerance in transgenic tobacco. Finally, we observed that cold induces the degradation of the MdCIbHLH1 protein in apple and that this degradation was potentially mediated by ubiquitination and sumoylation. Conclusions Based on these findings, MdCIbHLH1 encodes a transcription factor that is important for the cold tolerance response in apple. PMID:22336381

NF-κB (p65) negatively regulates myocardin-induced cardiomyocyte hypertrophy through multiple mechanisms.

PubMed

Liao, Xing-Hua; Wang, Nan; Zhao, Dong-Wei; Zheng, De-Liang; Zheng, Li; Xing, Wen-Jing; Zhou, Hao; Cao, Dong-Sun; Zhang, Tong-Cun

2014-12-01

Myocardin is well known to play a key role in the development of cardiomyocyte hypertrophy. But the exact molecular mechanism regulating myocardin stability and transactivity to affect cardiomyocyte hypertrophy has not been studied clearly. We now report that NF-κB (p65) can inhibit myocardin-induced cardiomyocyte hypertrophy. Then we explore the molecular mechanism of this response. First, we show that p65 can functionally repress myocardin transcriptional activity and also reduce the protein expression of myocardin. Second, the function of myocardin can be regulated by epigenetic modifications. Myocardin sumoylation is known to transactivate cardiac genes, but whether p65 can inhibit SUMO modification of myocardin is still not clear. Our data show that p65 weakens myocardin transcriptional activity through attenuating SUMO modification of myocardin by SUMO1/PIAS1, thereby impairing myocardin-mediated cardiomyocyte hypertrophy. Furthermore, the expression of myocardin can be regulated by several microRNAs, which play important roles in the development and function of the heart and muscle. We next investigated potential role of miR-1 in cardiac hypotrophy. Our results show that p65 can upregulate the level of miR-1 and miR-1 can decrease protein expression of myocardin in cardiac myocytes. Notably, miR-1 expression is also controlled by myocardin, leading to a feedback loop. These data thus provide important and novel insights into the function that p65 inhibits myocardin-mediated cardiomyocyte hypertrophy by downregulating the expression and SUMO modification of myocardin and enhancing the expression of miR-1. Copyright © 2014 Elsevier Inc. All rights reserved.

Does Leisure Time as a Stress Coping Resource Increase Affective Complexity? Applying the Dynamic Model of Affect (DMA).

PubMed

Qian, Xinyi Lisa; Yarnal, Careen M; Almeida, David M

2013-01-01

Affective complexity, a manifestation of psychological well-being, refers to the relative independence between positive and negative affect (PA, NA). According to the Dynamic Model of Affect (DMA), stressful situations lead to highly inverse PA-NA relationship, reducing affective complexity. Meanwhile, positive events can sustain affective complexity by restoring PA-NA independence. Leisure, a type of positive events, has been identified as a coping resource. This study used the DMA to assess whether leisure time helps restore affective complexity on stressful days. We found that on days with more leisure time than usual, an individual experienced less negative PA-NA relationship after daily stressful events. The finding demonstrates the value of leisure time as a coping resource and the DMA's contribution to coping research.

Visual Complexity and Affect: Ratings Reflect More Than Meets the Eye.

PubMed

Madan, Christopher R; Bayer, Janine; Gamer, Matthias; Lonsdorf, Tina B; Sommer, Tobias

2017-01-01

Pictorial stimuli can vary on many dimensions, several aspects of which are captured by the term 'visual complexity.' Visual complexity can be described as, "a picture of a few objects, colors, or structures would be less complex than a very colorful picture of many objects that is composed of several components." Prior studies have reported a relationship between affect and visual complexity, where complex pictures are rated as more pleasant and arousing. However, a relationship in the opposite direction, an effect of affect on visual complexity, is also possible; emotional arousal and valence are known to influence selective attention and visual processing. In a series of experiments, we found that ratings of visual complexity correlated with affective ratings, and independently also with computational measures of visual complexity. These computational measures did not correlate with affect, suggesting that complexity ratings are separately related to distinct factors. We investigated the relationship between affect and ratings of visual complexity, finding an 'arousal-complexity bias' to be a robust phenomenon. Moreover, we found this bias could be attenuated when explicitly indicated but did not correlate with inter-individual difference measures of affective processing, and was largely unrelated to cognitive and eyetracking measures. Taken together, the arousal-complexity bias seems to be caused by a relationship between arousal and visual processing as it has been described for the greater vividness of arousing pictures. The described arousal-complexity bias is also of relevance from an experimental perspective because visual complexity is often considered a variable to control for when using pictorial stimuli.

Visual Complexity and Affect: Ratings Reflect More Than Meets the Eye

PubMed Central

Madan, Christopher R.; Bayer, Janine; Gamer, Matthias; Lonsdorf, Tina B.; Sommer, Tobias

2018-01-01

Pictorial stimuli can vary on many dimensions, several aspects of which are captured by the term ‘visual complexity.’ Visual complexity can be described as, “a picture of a few objects, colors, or structures would be less complex than a very colorful picture of many objects that is composed of several components.” Prior studies have reported a relationship between affect and visual complexity, where complex pictures are rated as more pleasant and arousing. However, a relationship in the opposite direction, an effect of affect on visual complexity, is also possible; emotional arousal and valence are known to influence selective attention and visual processing. In a series of experiments, we found that ratings of visual complexity correlated with affective ratings, and independently also with computational measures of visual complexity. These computational measures did not correlate with affect, suggesting that complexity ratings are separately related to distinct factors. We investigated the relationship between affect and ratings of visual complexity, finding an ‘arousal-complexity bias’ to be a robust phenomenon. Moreover, we found this bias could be attenuated when explicitly indicated but did not correlate with inter-individual difference measures of affective processing, and was largely unrelated to cognitive and eyetracking measures. Taken together, the arousal-complexity bias seems to be caused by a relationship between arousal and visual processing as it has been described for the greater vividness of arousing pictures. The described arousal-complexity bias is also of relevance from an experimental perspective because visual complexity is often considered a variable to control for when using pictorial stimuli. PMID:29403412

Does Leisure Time as a Stress Coping Resource Increase Affective Complexity? Applying the Dynamic Model of Affect (DMA)

PubMed Central

Qian, Xinyi (Lisa); Yarnal, Careen M.; Almeida, David M.

2013-01-01

Affective complexity, a manifestation of psychological well-being, refers to the relative independence between positive and negative affect (PA, NA). According to the Dynamic Model of Affect (DMA), stressful situations lead to highly inverse PA-NA relationship, reducing affective complexity. Meanwhile, positive events can sustain affective complexity by restoring PA-NA independence. Leisure, a type of positive events, has been identified as a coping resource. This study used the DMA to assess whether leisure time helps restore affective complexity on stressful days. We found that on days with more leisure time than usual, an individual experienced less negative PA-NA relationship after daily stressful events. The finding demonstrates the value of leisure time as a coping resource and the DMA’s contribution to coping research. PMID:24659826

Post-Translational Modification Control of Innate Immunity.

PubMed

Liu, Juan; Qian, Cheng; Cao, Xuetao

2016-07-19

A coordinated balance between the positive and negative regulation of pattern-recognition receptor (PRR)-initiated innate inflammatory responses is required to ensure the most favorable outcome for the host. Post-translational modifications (PTMs) of innate sensors and downstream signaling molecules influence their activity and function by inducing their covalent linkage to new functional groups. PTMs including phosphorylation and polyubiquitination have been shown to potently regulate innate inflammatory responses through the activation, cellular translocation, and interaction of innate receptors, adaptors, and downstream signaling molecules in response to infectious and dangerous signals. Other PTMs such as methylation, acetylation, SUMOylation, and succinylation are increasingly implicated in the regulation of innate immunity and inflammation. In this review, we focus on the roles of PTMs in controlling PRR-triggered innate immunity and inflammatory responses. The emerging roles of PTMs in the pathogenesis and potential treatment of infectious and inflammatory immune diseases are also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

A Proteomic Characterization of Factors Enriched at Nascent DNA Molecules

PubMed Central

Lopez-Contreras, Andres J.; Ruppen, Isabel; Nieto-Soler, Maria; Murga, Matilde; Rodriguez-Acebes, Sara; Remeseiro, Silvia; Rodrigo-Perez, Sara; Rojas, Ana M.; Mendez, Juan; Muñoz, Javier; Fernandez-Capetillo, Oscar

2013-01-01

SUMMARY DNA replication is facilitated by multiple factors that concentrate in the vicinity of replication forks. Here, we developed an approach that combines the isolation of proteins on nascent DNA chains with mass spectrometry (iPOND-MS), allowing a comprehensive proteomic characterization of the human replisome and replisome-associated factors. In addition to known replisome components, we provide a broad list of proteins that reside in the vicinity of the replisome, some of which were not previously associated with replication. For instance, our data support a link between DNA replication and the Williams-Beuren syndrome and identify ZNF24 as a replication factor. In addition, we reveal that SUMOylation is wide-spread for factors that concentrate near replisomes, which contrasts with lower UQylation levels at these sites. This resource provides a panoramic view of the proteins that concentrate in the surroundings of the replisome, which should facilitate future investigations on DNA replication and genome maintenance. PMID:23545495

PML IV/ARF interaction enhances p53 SUMO-1 conjugation, activation, and senescence

PubMed Central

Ivanschitz, Lisa; Takahashi, Yuki; Jollivet, Florence; Ayrault, Olivier; Le Bras, Morgane; de Thé, Hugues

2015-01-01

Promyelocytic leukemia protein (PML) nuclear bodies (NBs) recruit multiple partners, including p53 and many of its regulators. NBs are believed to facilitate several posttranslational modifications and are key regulators of senescence. PML, the organizer of NBs, is expressed as a number of splice variants that all efficiently recruit p53 partners. However, overexpression of only one of them, PML IV, triggers p53-driven senescence. Here, we show that PML IV specifically binds ARF, a key p53 regulator. Similar to ARF, PML IV enhances global SUMO-1 conjugation, particularly that of p53, resulting in p53 stabilization and activation. ARF interacts with and stabilizes the NB-associated UBC9 SUMO-conjugating enzyme, possibly explaining PML IV-enhanced SUMOylation. These results unexpectedly link two key tumor suppressors, highlighting their convergence for global control of SUMO conjugation, p53 activation, and senescence induction. PMID:26578773

Manipulation of ubiquitin/SUMO pathways in human herpesviruses infection.

PubMed

Gan, Jin; Qiao, Niu; Strahan, Roxanne; Zhu, Caixia; Liu, Lei; Verma, Subhash C; Wei, Fang; Cai, Qiliang

2016-11-01

Post-translational modification of proteins with ubiquitin/small ubiquitin-like modifier (SUMO) molecules triggers multiple signaling pathways that are critical for many aspects of cellular physiology. Given that viruses hijack the biosynthetic and degradative systems of their host, it is not surprising that viruses encode proteins to manipulate the host's cellular machinery for ubiquitin/SUMO modification at multiple levels. Infection with a herpesvirus, among the most ubiquitous human DNA viruses, has been linked to many human diseases, including cancers. The interplay between human herpesviruses and the ubiquitylation/SUMOylation modification system has been extensively investigated in the past decade. In this review, we present an overview of recent advances to address how the ubiquitin/SUMO-modified system alters the latency and lytic replication of herpesvirus and how herpesviruses usurp the ubiquitin/SUMO pathways against the host's intrinsic and innate immune response to favor their pathogenesis. Copyright © 2016 John Wiley & Sons, Ltd.

An in vitro FRET-based assay for the analysis of SUMO conjugation and isopeptidase cleavage.

PubMed

Stankovic-Valentin, Nicolas; Kozaczkiewicz, Lukasz; Curth, Katja; Melchior, Frauke

2009-01-01

To measure rates of sumoylation and isopeptidase cleavage in vitro, we developed an enzyme assay that is based on fluorescence resonance energy transfer (FRET). FRET is a process by which the excited state energy of a fluorescent donor molecule is transferred to an acceptor molecule. Efficient energy transfer requires very close proximity, and can therefore be used as a read-out for covalent and non-covalent protein interactions. The assay described here uses bacterially expressed and purified YFP-SUMO-1 and CFP-RanGAP1 as model substrates that are covalently coupled in the presence of recombinant SUMO E1 and E2 enzymes and ATP. Reactions of 25 microl volume, set up in 384-wells plates, give sufficient signal for analysis. Consequently, this assay requires very low amounts of recombinant proteins and allows measurement of time courses in high-throughput format.

Curing APL through PML/RARA degradation by As2O3.

PubMed

Lallemand-Breitenbach, Valerie; Zhu, Jun; Chen, Zhu; de Thé, Hugues

2012-01-01

Acute promyelocytic leukemia (APL) is a hematological malignancy driven by the PML/RARA oncogene. The prognosis for patients with APL was revolutionized by two treatments: retinoic acid (RA) and As(2)O(3) (arsenic trioxide). These were both shown a posteriori to target PML/RARA, explaining their exquisite specificity for APL. Arsenic, as a single agent, cures up to 70% of patients, whereas APL patients treated with the combination of RA and As(2)O(3) reach a stunning 90% cure rate. Recent physiopathological models highlight the key role of RA- and As(2)O(3)-triggered PML/RARA degradation, and the molecular mechanisms underlying As(2)O(3)-induced PML/RARA degradation have been recently clarified. As discussed below, arsenic binding, oxidation, sumoylation on PML nuclear bodies, and RNF4-mediated ubiquitination all contribute to the As(2)O(3)-triggered catabolism of PML/RARA. Copyright © 2011 Elsevier Ltd. All rights reserved.

PML IV/ARF interaction enhances p53 SUMO-1 conjugation, activation, and senescence.

PubMed

Ivanschitz, Lisa; Takahashi, Yuki; Jollivet, Florence; Ayrault, Olivier; Le Bras, Morgane; de Thé, Hugues

2015-11-17

Promyelocytic leukemia protein (PML) nuclear bodies (NBs) recruit multiple partners, including p53 and many of its regulators. NBs are believed to facilitate several posttranslational modifications and are key regulators of senescence. PML, the organizer of NBs, is expressed as a number of splice variants that all efficiently recruit p53 partners. However, overexpression of only one of them, PML IV, triggers p53-driven senescence. Here, we show that PML IV specifically binds ARF, a key p53 regulator. Similar to ARF, PML IV enhances global SUMO-1 conjugation, particularly that of p53, resulting in p53 stabilization and activation. ARF interacts with and stabilizes the NB-associated UBC9 SUMO-conjugating enzyme, possibly explaining PML IV-enhanced SUMOylation. These results unexpectedly link two key tumor suppressors, highlighting their convergence for global control of SUMO conjugation, p53 activation, and senescence induction.

Post-translational modification of host proteins in pathogen-triggered defence signalling in plants.

PubMed

Stulemeijer, Iris J E; Joosten, Matthieu H A J

2008-07-01

Microbial plant pathogens impose a continuous threat to global food production. Similar to animals, an innate immune system allows plants to recognize pathogens and swiftly activate defence. To activate a rapid response, receptor-mediated pathogen perception and subsequent downstream signalling depends on post-translational modification (PTM) of components essential for defence signalling. We discuss different types of PTMs that play a role in mounting plant immunity, which include phosphorylation, glycosylation, ubiquitination, sumoylation, nitrosylation, myristoylation, palmitoylation and glycosylphosphatidylinositol (GPI)-anchoring. PTMs are rapid, reversible, controlled and highly specific, and provide a tool to regulate protein stability, activity and localization. Here, we give an overview of PTMs that modify components essential for defence signalling at the site of signal perception, during secondary messenger production and during signalling in the cytoplasm. In addition, we discuss effectors from pathogens that suppress plant defence responses by interfering with host PTMs.

Cognitive Complexity, Attitudinal Affect, and Dispersion in Affect Ratings for Products.

PubMed

Durand, Richard M

1979-04-01

The purpose of this study was to examine the relationships between cognitive complexity, attitudinal affect, and dispersion of affect scores (N = 102 male business administration undergraduates). Models of automobiles and toothpaste brands were the content domains studied. Analysis using Pearson product-moment correlation supported the hypothesis that cognitive complex Ss had a lower level of affect and greater dispersion of affect scores than did simpler Ss.

Epigenetic and Posttranslational Modifications in Light Signal Transduction and the Circadian Clock in Neurospora crassa

PubMed Central

Proietto, Marco; Bianchi, Michele Maria; Ballario, Paola; Brenna, Andrea

2015-01-01

Blue light, a key abiotic signal, regulates a wide variety of physiological processes in many organisms. One of these phenomena is the circadian rhythm presents in organisms sensitive to the phase-setting effects of blue light and under control of the daily alternation of light and dark. Circadian clocks consist of autoregulatory alternating negative and positive feedback loops intimately connected with the cellular metabolism and biochemical processes. Neurospora crassa provides an excellent model for studying the molecular mechanisms involved in these phenomena. The White Collar Complex (WCC), a blue-light receptor and transcription factor of the circadian oscillator, and Frequency (FRQ), the circadian clock pacemaker, are at the core of the Neurospora circadian system. The eukaryotic circadian clock relies on transcriptional/translational feedback loops: some proteins rhythmically repress their own synthesis by inhibiting the activity of their transcriptional factors, generating self-sustained oscillations over a period of about 24 h. One of the basic mechanisms that perpetuate self-sustained oscillations is post translation modification (PTM). The acronym PTM generically indicates the addition of acetyl, methyl, sumoyl, or phosphoric groups to various types of proteins. The protein can be regulatory or enzymatic or a component of the chromatin. PTMs influence protein stability, interaction, localization, activity, and chromatin packaging. Chromatin modification and PTMs have been implicated in regulating circadian clock function in Neurospora. Research into the epigenetic control of transcription factors such as WCC has yielded new insights into the temporal modulation of light-dependent gene transcription. Here we report on epigenetic and protein PTMs in the regulation of the Neurospora crassa circadian clock. We also present a model that illustrates the molecular mechanisms at the basis of the blue light control of the circadian clock. PMID:26198228

Membrane Association of the PTEN Tumor Suppressor: Electrostatic Interaction with Phos-phatidylserine-Containing Bilayers and Regulatory Role of the C-Terminal Tail

PubMed Central

Shenoy, Siddharth S.; Nanda, Hirsh; Lösche, Mathias

2012-01-01

The phosphatidylinositolphosphate phosphatase PTEN is the second most frequently mutated protein in human tumors. Its membrane association, allosteric activation and membrane dissociation are poorly understood. We recently reported PTEN binding affinities to membranes of different compositions and a preliminary investigation of the protein-membrane complex with neutron reflectometry (NR). Here we use NR to validate molecular dynamics (MD) simulations of the protein and study conformational differences of the protein in solution and on anionic membranes. NR shows that full-length PTEN binds to such membranes roughly in the conformation and orientation suggested by the crystal structure of a truncated PTEN protein, in contrast with a recently presented model which suggested that membrane binding depends critically on the SUMOylation of the CBR3 loop of PTEN’s C2 domain. Our MD simulations confirm that PTEN is peripherally bound to the bilayer surface and show slight differences of the protein structure in solution and in the membrane-bound state, where the protein body flattens against the bilayer surface. PTEN’s C2 domain binds phosphatidylserine (PS) tightly through its CBR3 loop, and its phosphatase domain also forms electrostatic interactions with PS. NR and MD results show consistently that PTEN’s unstructured, anionic C-terminal tail is repelled from the bilayer surface. In contrast, this tail is tightly tugged against the C2 domain in solution, partially obstructing the membrane-binding interface of the protein. Arresting the C-terminal tail in this conformation by phosphorylation may provide a control mechanism for PTEN’s membrane binding and activity. PMID:23073177

Tax posttranslational modifications and interaction with calreticulin in MT-2 cells and human peripheral blood mononuclear cells of human T cell lymphotropic virus type-I-associated myelopathy/tropical spastic paraparesis patients.

PubMed

Medina, Fernando; Quintremil, Sebastian; Alberti, Carolina; Barriga, Andres; Cartier, Luis; Puente, Javier; Ramírez, Eugenio; Ferreira, Arturo; Tanaka, Yuetsu; Valenzuela, Maria Antonieta

2014-04-01

The human retrovirus human T cell lymphotropic virus type-I (HTLV-1) is the etiologic agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Axonal degeneration in HAM/TSP patients occurs without neuron infection, with the secreted viral Tax protein proposed to be involved. We previously found that Tax secreted into the culture medium of MT-2 cells (HTLV-1-infected cell line) produced neurite retraction in neuroblastoma cells differentiated to neuronal type. To assess the relevance of Tax posttranslational modifications on this effect, we addressed the question of whether Tax secreted by MT-2 cells and peripheral blood mononuclear cells (PBMCs) of HTLV-1-infected subjects is modified. The interaction of Tax with calreticulin (CRT) that modulates intracellular Tax localization and secretion has been described. We studied Tax localization and modifications in MT-2 cells and its interaction with CRT. Intracellular Tax in MT-2 cells was assessed by flow cytometry, corresponding mainly to a 71-kDa protein followed by western blot. This protein reported as a chimera with gp21 viral protein-confirmed by mass spectrometry-showed no ubiquitination or SUMOylation. The Tax-CRT interaction was determined by confocal microscopy and coimmunoprecipitation. Extracellular Tax from HAM/TSP PBMCs is ubiquitinated according to western blot, and its interaction with CRT was shown by coimmunoprecipitation. A positive correlation between Tax and CRT secretion was observed in HAM/TSP PBMCs and asymptomatic carriers. For both proteins inhibitors and activators of secretion showed secretion through the endoplasmic reticulum-Golgi complex. Tax, present in PBMC culture medium, produced neurite retraction in differentiated neuroblastoma cells. These results suggest that Tax, whether ubiquitinated or not, is active for neurite retraction.

Membrane association of the PTEN tumor suppressor: electrostatic interaction with phosphatidylserine-containing bilayers and regulatory role of the C-terminal tail.

PubMed

Shenoy, Siddharth S; Nanda, Hirsh; Lösche, Mathias

2012-12-01

The phosphatidylinositolphosphate phosphatase PTEN is the second most frequently mutated protein in human tumors. Its membrane association, allosteric activation and membrane dissociation are poorly understood. We recently reported PTEN binding affinities to membranes of different compositions (Shenoy et al., 2012, PLoS ONE 7, e32591) and a preliminary investigation of the protein-membrane complex with neutron reflectometry (NR). Here we use NR to validate molecular dynamics (MD) simulations of the protein and study conformational differences of the protein in solution and on anionic membranes. NR shows that full-length PTEN binds to such membranes roughly in the conformation and orientation suggested by the crystal structure of a truncated PTEN protein, in contrast with a recently presented model which suggested that membrane binding depends critically on the SUMOylation of the CBR3 loop of PTEN's C2 domain. Our MD simulations confirm that PTEN is peripherally bound to the bilayer surface and show slight differences of the protein structure in solution and in the membrane-bound state, where the protein body flattens against the bilayer surface. PTEN's C2 domain binds phosphatidylserine (PS) tightly through its CBR3 loop, and its phosphatase domain also forms electrostatic interactions with PS. NR and MD results show consistently that PTEN's unstructured, anionic C-terminal tail is repelled from the bilayer surface. In contrast, this tail is tightly tugged against the C2 domain in solution, partially obstructing the membrane-binding interface of the protein. Arresting the C-terminal tail in this conformation by phosphorylation may provide a control mechanism for PTEN's membrane binding and activity. Copyright © 2012 Elsevier Inc. All rights reserved.

Acetylation at lysine 346 controls the transforming activity of the HTLV-1 Tax oncoprotein in the Rat-1 fibroblast model

PubMed Central

2013-01-01

Background Transformation by the Tax oncoprotein of the human T cell leukemia virus type 1 (HTLV-1) is governed by actions on cellular regulatory signals, including modulation of specific cellular gene expression via activation of signaling pathways, acceleration of cell cycle progression via stimulation of cyclin-dependent kinase activity leading to retinoblastoma protein (pRb) hyperphosphorylation and perturbation of survival signals. These actions control early steps in T cell transformation and development of Adult T cell leukemia (ATL), an aggressive malignancy of HTLV-1 infected T lymphocytes. Post-translational modifications of Tax by phosphorylation, ubiquitination, sumoylation and acetylation have been implicated in Tax-mediated activation of the NF-κB pathway, a key function associated with Tax transforming potential. Results In this study, we demonstrate that acetylation at lysine K346 in the carboxy-terminal domain of Tax is modulated in the Tax nuclear bodies by the acetyltransferase p300 and the deacetylases HDAC5/7 and controls phosphorylation of the tumor suppressor pRb by Tax-cyclin D3-CDK4-p21CIP complexes. This property correlates with the inability of the acetylation deficient K346R mutant, but not the acetylation mimetic K346Q mutant, to promote anchorage-independent growth of Rat-1 fibroblasts. By contrast, acetylation at lysine K346 had no effects on the ability of Tax carboxy-terminal PDZ-binding domain to interact with the tumor suppressor hDLG. Conclusions The identification of the acetyltransferase p300 and the deacetylase HDAC7 as enzymes modulating Tax acetylation points to new therapeutic targets for the treatment of HTLV-1 infected patients at risk of developing ATL. PMID:23880157

Over-accumulation of nuclear IGF-1 receptor in tumor cells requires elevated expression of the receptor and the SUMO-conjugating enzyme Ubc9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deng, Hua; Lin, Yingbo; Badin, Margherita

2011-01-14

Research highlights: {yields} SUMOylation mediates nuclear translocation of IGF-1R which activates transcription. {yields} Here we show that nuclear IGF-1R over-accumulates in tumor cells. {yields} This requires overexpression of the receptor that is a common feature in tumor cells. {yields} An increased expression of the SUMO ligase Ubc9 seems to be an involved mechanism too. -- Abstract: The insulin-like growth factor 1 receptor (IGF-1R) plays crucial roles in tumor cell growth and is overexpressed in many cancers. IGF-1R's trans-membrane kinase signaling pathways have been well characterized. Very recently, we showed that SUMOylation mediates nuclear translocation of the IGF-1R, and that nuclearmore » IGF-1R (nIGF-1R) binds to enhancer regions and activates transcription. We identified three lysine residues in the {beta}-subunit of the receptor and that mutation of these blocks nuclear translocation and gene activation. Furthermore, accumulation of nIGF-1R was proven strongly dependent on the specific SUMO-conjugating enzyme Ubc9. Here we show that nIGF-1R originates solely from the cell membrane and that phosphorylation of the core tyrosine residues of the receptor kinase is crucial for nuclear accumulation. We also compared the levels of nIGF-1R, measured as nuclear/membrane ratios, in tumor and normal cells. We found that the breast cancer cell line MCF-7 has 13-fold higher amounts of nIGF-1R than breast epithelial cells (IME) which showed only a small amount of nIGF-1R. In comparison, the total expression of IGF-1R was only 3.7- higher in MCF-7. Comparison of several other tumor and normal cell lines showed similar tumor cell over-accumulation of nIGF-1R, exceeding the total receptor expression substantially. Ectopic overexpression (>10-fold) of the receptor increased nIGF-1R in IME cells but not to that high level as in wild type MCF-7. The levels of Ubc9 were higher in all tumor cell lines, compared to the normal cells, and this probably contributes to over-accumulation of nIGF-1R. Over-accumulation of nIGF-1R may contribute to deregulated gene expression and therewith play a pathophysiological role in cancer cells.« less

Does the relationship between affect complexity and self-esteem differ in young-old and old-old participants?

PubMed

Bodner, Ehud; Palgi, Yuval; Kaveh, Dvir

2013-09-01

This study examines whether the relationship between positive affect (PA) and negative affect (NA) is more complex among old-old than among young-old participants and whether the independence and potential co-occurrence of both PA and NA (affect complexity) is related to higher self-esteem (SE) among older participants. A convenience sample of 311 participants was divided into 2 groups: young-old, aged 65-79 years (n = 212), and old-old, aged 80-93 years (n = 99), participants. PA and NA were measured by the Positive and Negative Affect Schedule and SE was measured by the Self-Esteem Questionnaire. The findings show that PA and NA are less strongly related and even positively related to each other among older people and that SE is higher among the young-old compared with the old-old participants. Finally, affect complexity is positively related to a higher degree of SE among the old-old participants. These findings may imply that the affect complexity is associated with buffering the noxious effect of deteriorating SE in old age. Future studies should examine further the intrapersonal relationship between affect complexity and SE in late life.

Effects of trial complexity on decision making.

PubMed

Horowitz, I A; ForsterLee, L; Brolly, I

1996-12-01

The ability of a civil jury to render fair and rational decisions in complex trials has been questioned. However, the nature, dimensions, and effects of trial complexity on decision making have rarely been addressed. In this research, jury-eligible adults saw a videotape of a complex civil trial that varied in information load and complexity of the language of the witnesses. Information load and complexity differentially affected liability and compensatory decisions. An increase in the number of plaintiffs decreased blameworthiness assigned to the defendant despite contrary evidence and amount of probative evidence processed. Complex language did not affect memory but did affect jurors' ability to appropriately compensate differentially worthy plaintiffs. Jurors assigned compensatory awards commensurate with the plaintiffs' injuries only under low-load and less complex language conditions.

In Vitro Characterization of Chain Depolymerization Activities of SUMO-Specific Proteases.

PubMed

Eckhoff, Julia; Dohmen, R Jürgen

2016-01-01

SUMO-specific proteases, known as Ulps in baker's yeast and SENPs in humans, have important roles in controlling the dynamics of SUMO-modified proteins. They display distinct modes of action and specificity, in that they may act on the SUMO precursor, mono-sumoylated, and/or polysumoylated proteins, and they might be specific for substrates with certain SUMO paralogs. SUMO chains may be dismantled either by endo or exo mechanisms. Biochemical characterization of a protease usually requires purification of the protein of interest. Developing a purification protocol, however, can be very difficult, and in some cases, isolation of a protease in its pure form may go along with a substantial loss of activity. To characterize the reaction mechanism of Ulps, we have developed an in vitro assay, which makes use of substrates endowed with artificial poly-SUMO chains of defined lengths, and S. cerevisiae Ulp enzymes in crude extract from E. coli. This fast and economic approach should be applicable to SUMO-specific proteases from other species as well.

Role of novel histone modifications in cancer

PubMed Central

Shanmugam, Muthu K.; Arfuso, Frank; Arumugam, Surendar; Chinnathambi, Arunachalam; Jinsong, Bian; Warrier, Sudha; Wang, Ling Zhi; Kumar, Alan Prem; Ahn, Kwang Seok; Sethi, Gautam; Lakshmanan, Manikandan

2018-01-01

Oncogenesis is a multistep process mediated by a variety of factors including epigenetic modifications. Global epigenetic post-translational modifications have been detected in almost all cancers types. Epigenetic changes appear briefly and do not involve permanent changes to the primary DNA sequence. These epigenetic modifications occur in key oncogenes, tumor suppressor genes, and transcription factors, leading to cancer initiation and progression. The most commonly observed epigenetic changes include DNA methylation, histone lysine methylation and demethylation, histone lysine acetylation and deacetylation. However, there are several other novel post-translational modifications that have been observed in recent times such as neddylation, sumoylation, glycosylation, phosphorylation, poly-ADP ribosylation, ubiquitination as well as transcriptional regulation and these have been briefly discussed in this article. We have also highlighted the diverse epigenetic changes that occur during the process of tumorigenesis and described the role of histone modifications that can occur on tumor suppressor genes as well as oncogenes, which regulate tumorigenesis and can thus form the basis of novel strategies for cancer therapy. PMID:29541423

Role of Smad signaling in kidney disease.

PubMed

Zhang, Yanhua; Wang, Songyan; Liu, Shengmao; Li, Chunguang; Wang, Ji

2015-12-01

Smads are the key intermediates of canonical transforming growth factor-beta (TGF-β) signaling. These intermediates are divided into three distinct subgroups based on their role in TGF-β family signal transduction: Receptor-regulated Smads (R-Smads) 1, 2, 3, 5 and 8, common Smad4, and inhibitory Smads6 and 7. TGF-β signaling through Smad pathway involves phosphorylation, ubiquitination, sumoylation, acetylation, and protein-protein interactions with mitogen-activated protein kinases, PI3K-Akt/PKB, and Wnt/GSK-3. Several studies have suggested that upregulation or downregulation of TGF-β/Smad signaling pathways may be a pathogenic mechanism in the progression of chronic kidney disease. Smad2 and 3 are the two major downstream R-Smads in TGF-β-mediated renal fibrosis, while Smad7 also controls renal inflammation. In this review, we characterize the role of Smads in kidney disease, describe the molecular mechanisms, and discuss the potential of Smads as a therapeutic target in chronic kidney disease.

Clearance of PML/RARA-bound promoters suffice to initiate APL differentiation.

PubMed

Vitaliano-Prunier, Adeline; Halftermeyer, Juliane; Ablain, Julien; de Reynies, Aurélien; Peres, Laurent; Le Bras, Morgane; Metzger, Daniel; de Thé, Hugues

2014-12-11

PML/RARA, a potent transcriptional inhibitor of nuclear receptor signaling, represses myeloid differentiation genes and drives acute promyelocytic leukemia (APL). Association of the retinoid X receptor-α (RXRA) coreceptor to PML/RARA is required for transformation, with RXRA promoting its efficient DNA binding. APL is exquisitely sensitive to retinoic acid (RA) and arsenic trioxide (arsenic), which both trigger cell differentiation in vivo. Whereas RA elicits transcriptional activation of PML/RARA targets, how arsenic triggers differentiation remains unclear. Here we demonstrate that extinction of PML/RARA triggers terminal differentiation in vivo. Similarly, ablation of retinoid X receptors loosens PML/RARA DNA binding, inducing terminal differentiation of APL cells ex vivo or in vivo. RXRA sumoylation directly contributes to PML/RARA-dependent transformation ex vivo, presumably by enhancing transcriptional repression. Thus, APL differentiation is a default program triggered by clearance of PML/RARA-bound promoters, rather than obligatory active transcriptional activation, explaining how arsenic elicits APL maturation through PML/RARA degradation. © 2014 by The American Society of Hematology.

Tax Posttranslational Modifications and Interaction with Calreticulin in MT-2 Cells and Human Peripheral Blood Mononuclear Cells of Human T Cell Lymphotropic Virus Type-I-Associated Myelopathy/Tropical Spastic Paraparesis Patients

PubMed Central

Medina, Fernando; Quintremil, Sebastian; Alberti, Carolina; Barriga, Andres; Cartier, Luis; Puente, Javier; Ramírez, Eugenio; Ferreira, Arturo; Tanaka, Yuetsu

2014-01-01

Abstract The human retrovirus human T cell lymphotropic virus type-I (HTLV-1) is the etiologic agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Axonal degeneration in HAM/TSP patients occurs without neuron infection, with the secreted viral Tax protein proposed to be involved. We previously found that Tax secreted into the culture medium of MT-2 cells (HTLV-1-infected cell line) produced neurite retraction in neuroblastoma cells differentiated to neuronal type. To assess the relevance of Tax posttranslational modifications on this effect, we addressed the question of whether Tax secreted by MT-2 cells and peripheral blood mononuclear cells (PBMCs) of HTLV-1-infected subjects is modified. The interaction of Tax with calreticulin (CRT) that modulates intracellular Tax localization and secretion has been described. We studied Tax localization and modifications in MT-2 cells and its interaction with CRT. Intracellular Tax in MT-2 cells was assessed by flow cytometry, corresponding mainly to a 71-kDa protein followed by western blot. This protein reported as a chimera with gp21 viral protein—confirmed by mass spectrometry—showed no ubiquitination or SUMOylation. The Tax–CRT interaction was determined by confocal microscopy and coimmunoprecipitation. Extracellular Tax from HAM/TSP PBMCs is ubiquitinated according to western blot, and its interaction with CRT was shown by coimmunoprecipitation. A positive correlation between Tax and CRT secretion was observed in HAM/TSP PBMCs and asymptomatic carriers. For both proteins inhibitors and activators of secretion showed secretion through the endoplasmic reticulum–Golgi complex. Tax, present in PBMC culture medium, produced neurite retraction in differentiated neuroblastoma cells. These results suggest that Tax, whether ubiquitinated or not, is active for neurite retraction. PMID:24321043

Time-Based Indicators of Emotional Complexity: Interrelations and Correlates

PubMed Central

Grühn, Daniel; Lumley, Mark A.; Diehl, Manfred; Labouvie-Vief, Gisela

2012-01-01

Emotional complexity has been regarded as one correlate of adaptive emotion regulation in adulthood. One novel and potentially valuable approach to operationalizing emotional complexity is to use reports of emotions obtained repeatedly in real time, which can generate a number of potential time-based indicators of emotional complexity. It is not known, however, how these indicators relate to each other, to other measures of affective complexity, such as those derived from a cognitive-developmental view of emotional complexity, or to measures of adaptive functioning, such as well-being. A sample of 109 adults, aged 23 to 90 years, participated in an experience-sampling study and reported their negative and positive affect five times a day for one week. Based on these reports, we calculated nine different time-based indicators potentially reflecting emotional complexity. Analyses showed three major findings: First, the indicators showed a diverse pattern of interrelations suggestive of four distinct components of emotional complexity. Second, age was generally not related to time-based indicators of emotional complexity; however, older adults showed overall low variability in negative affect. Third, time-based indicators of emotional complexity were either unrelated or inversely related to measures of adaptive functioning; that is, these measures tended to predict a less adaptive profile, such as lower subjective and psychological well-being. In sum, time-based indicators of emotional complexity displayed a more complex and less beneficial picture than originally thought. In particular, variability in negative affect seems to indicate suboptimal adjustments. Future research would benefit from collecting empirical data for the interrelations and correlates of time-based indicators of emotional complexity in different contexts. PMID:23163712

Mediation, moderation, and context: Understanding complex relations among cognition, affect, and health behaviour.

PubMed

Kiviniemi, Marc T; Ellis, Erin M; Hall, Marissa G; Moss, Jennifer L; Lillie, Sarah E; Brewer, Noel T; Klein, William M P

2018-01-01

Researchers have historically treated cognition and affect as separate constructs in motivating health behaviour. We present a framework and empirical evidence for complex relations between cognition and affect in predicting health behaviour. Main Outcome, Design and Results: First, affect and cognition can mediate each other's relation to health behaviour. Second, affect and cognition can moderate the other's impact. Third, context can change the interplay of affect and cognition. Fourth, affect and cognition may be indelibly fused in some psychological constructs (e.g. worry, anticipated regret and reactance). These four propositions in our framework are not mutually exclusive. Examination of the types of complex relations described here can benefit theory development, empirical testing of theories and intervention design. Doing so will advance the understanding of mechanisms involved in regulation of health behaviours and the effectiveness of interventions to change health behaviours.

Study designs for identification of rare disease variants in complex diseases: the utility of family-based designs.

PubMed

Ionita-Laza, Iuliana; Ottman, Ruth

2011-11-01

The recent progress in sequencing technologies makes possible large-scale medical sequencing efforts to assess the importance of rare variants in complex diseases. The results of such efforts depend heavily on the use of efficient study designs and analytical methods. We introduce here a unified framework for association testing of rare variants in family-based designs or designs based on unselected affected individuals. This framework allows us to quantify the enrichment in rare disease variants in families containing multiple affected individuals and to investigate the optimal design of studies aiming to identify rare disease variants in complex traits. We show that for many complex diseases with small values for the overall sibling recurrence risk ratio, such as Alzheimer's disease and most cancers, sequencing affected individuals with a positive family history of the disease can be extremely advantageous for identifying rare disease variants. In contrast, for complex diseases with large values of the sibling recurrence risk ratio, sequencing unselected affected individuals may be preferable.

SUMO-modified insulin-like growth factor 1 receptor (IGF-1R) increases cell cycle progression and cell proliferation.

PubMed

Lin, Yingbo; Liu, Hongyu; Waraky, Ahmed; Haglund, Felix; Agarwal, Prasoon; Jernberg-Wiklund, Helena; Warsito, Dudi; Larsson, Olle

2017-10-01

Increasing number of studies have shown nuclear localization of the insulin-like growth factor 1 receptor (nIGF-1R) in tumor cells and its links to adverse clinical outcome in various cancers. Any obvious cell physiological roles of nIGF-1R have, however, still not been disclosed. Previously, we reported that IGF-1R translocates to cell nucleus and modulates gene expression by binding to enhancers, provided that the receptor is SUMOylated. In this study, we constructed stable transfectants of wild type IGF1R (WT) and triple-SUMO-site-mutated IGF1R (TSM) using igf1r knockout mouse fibroblasts (R-). Cell clones (R-WT and R-TSM) expressing equal amounts of IGF-1R were selected for experiments. Phosphorylation of IGF-1R, Akt, and Erk upon IGF-1 stimulation was equal in R-WT and R-TSM. WT was confirmed to enter nuclei. TSM did also undergo nuclear translocation, although to a lesser extent. This may be explained by that TSM heterodimerizes with insulin receptor, which is known to translocate to cell nuclei. R-WT proliferated substantially faster than R-TSM, which did not differ significantly from the empty vector control. Upon IGF-1 stimulation G1-S-phase progression of R-WT increased from 12 to 38%, compared to 13 to 20% of R-TSM. The G1-S progression of R-WT correlated with increased expression of cyclin D1, A, and CDK2, as well as downregulation of p27. This suggests that SUMO-IGF-1R affects upstream mechanisms that control and coordinate expression of cell cycle regulators. Further studies to identify such SUMO-IGF-1R dependent mechanisms seem important. © 2017 The Authors. Journal of Cellular Physiology Published by Wiley Periodicals Inc.

E1B-55K mediated regulation of RNF4 STUbL promotes HAdV gene expression.

PubMed

Müncheberg, Sarah; Hay, Ron T; Ip, Wing H; Meyer, Tina; Weiß, Christina; Brenke, Jara; Masser, Sawinee; Hadian, Kamyar; Dobner, Thomas; Schreiner, Sabrina

2018-04-25

HAdV E1B-55K is a multifunctional regulator of productive viral replication and oncogenic transformation in non-permissive mammalian cells. These functions depend on E1B-55K's posttranslational modification with the SUMO protein and its binding to HAdV E4orf6. Both early viral proteins recruit specific host factors to form an E3 Ubiquitin ligase complex that targets antiviral host substrates for proteasomal degradation. Recently, we reported that the PML-NB-associated factor Daxx represses efficient HAdV productive infection and is proteasomally degraded via a SUMO-E1B-55K-dependent, E4orf6-independent pathway, the details of which remained to be established.RNF4, a cellular SUMO-targeted Ubiquitin ligase (STUbL), induces ubiquitinylation of specific SUMOylated proteins and plays an essential role during DNA repair. Here, we show that E1B-55K recruits RNF4 to the insoluble nuclear matrix fraction of the infected cell to support RNF4/Daxx association, promoting Daxx PTM, and thus inhibiting this antiviral factor. Removing RNF4 from infected cells using RNAi resulted in blocking the proper establishment of viral replication centers and significantly diminished viral gene expression. These results provide a model for how HAdV antagonize the antiviral host responses by exploiting the functional capacity of cellular STUbLs. Thus, RNF4 and its STUbL function represent a positive factor during lytic infection and a novel candidate for future therapeutic antiviral intervention strategies. IMPORTANCE Daxx is a PML-NB-associated transcription factor, which was recently shown to repress efficient HAdV productive infection. To counteract this antiviral measurement during infection, Daxx is degraded via a novel pathway including viral E1B-55K and host proteasomes. This virus-mediated degradation is independent of the classical HAdV E3 Ubiquitin ligase complex, which is essential during viral infection to target other host antiviral substrates. To maintain productive viral life cycle, HAdV E1B-55K early viral protein inhibits the chromatin-remodeling factor Daxx in a SUMO-dependent manner. In addition viral E1B-55K protein recruits the STUbL RNF4 and sequesters it into the insoluble fraction of the infected cell. E1B-55K promotes complex formation between RNF4 and E1B-55K targeted Daxx protein, supporting Daxx posttranslational modification prior to functional inhibition. Hence, RNF4 represents a novel host factor, which is beneficial for HAdV gene expression by supporting Daxx counteraction. In this regard, RNF4 and other STUbL proteins might represent novel targets for therapeutic intervention. Copyright © 2018 American Society for Microbiology.

A BEN-domain-containing protein associates with heterochromatin and represses transcription.

PubMed

Sathyan, Kizhakke M; Shen, Zhen; Tripathi, Vidisha; Prasanth, Kannanganattu V; Prasanth, Supriya G

2011-09-15

In eukaryotes, higher order chromatin structure governs crucial cellular processes including DNA replication, transcription and post-transcriptional gene regulation. Specific chromatin-interacting proteins play vital roles in the maintenance of chromatin structure. We have identified BEND3, a quadruple BEN domain-containing protein that is highly conserved amongst vertebrates. BEND3 colocalizes with HP1 and H3 trimethylated at K9 at heterochromatic regions in mammalian cells. Using an in vivo gene locus, we have been able to demonstrate that BEND3 associates with the locus only when it is heterochromatic and dissociates upon activation of transcription. Furthermore, tethering BEND3 inhibits transcription from the locus, indicating that BEND3 is involved in transcriptional repression through its interaction with histone deacetylases and Sall4, a transcription repressor. We further demonstrate that BEND3 is SUMOylated and that such modifications are essential for its role in transcriptional repression. Finally, overexpression of BEND3 causes premature chromatin condensation and extensive heterochromatinization, resulting in cell cycle arrest. Taken together, our data demonstrate the role of a novel heterochromatin-associated protein in transcriptional repression.

A BEN-domain-containing protein associates with heterochromatin and represses transcription

PubMed Central

Sathyan, Kizhakke M.; Shen, Zhen; Tripathi, Vidisha; Prasanth, Kannanganattu V.; Prasanth, Supriya G.

2011-01-01

In eukaryotes, higher order chromatin structure governs crucial cellular processes including DNA replication, transcription and post-transcriptional gene regulation. Specific chromatin-interacting proteins play vital roles in the maintenance of chromatin structure. We have identified BEND3, a quadruple BEN domain-containing protein that is highly conserved amongst vertebrates. BEND3 colocalizes with HP1 and H3 trimethylated at K9 at heterochromatic regions in mammalian cells. Using an in vivo gene locus, we have been able to demonstrate that BEND3 associates with the locus only when it is heterochromatic and dissociates upon activation of transcription. Furthermore, tethering BEND3 inhibits transcription from the locus, indicating that BEND3 is involved in transcriptional repression through its interaction with histone deacetylases and Sall4, a transcription repressor. We further demonstrate that BEND3 is SUMOylated and that such modifications are essential for its role in transcriptional repression. Finally, overexpression of BEND3 causes premature chromatin condensation and extensive heterochromatinization, resulting in cell cycle arrest. Taken together, our data demonstrate the role of a novel heterochromatin-associated protein in transcriptional repression. PMID:21914818

Poly-Small Ubiquitin-like Modifier (PolySUMO)-binding Proteins Identified through a String Search*

PubMed Central

Sun, Huaiyu; Hunter, Tony

2012-01-01

Polysumoylation is a crucial cellular response to stresses against genomic integrity or proteostasis. Like the small ubiquitin-like modifier (SUMO)-targeted ubiquitin ligase RNF4, proteins with clustered SUMO-interacting motifs (SIMs) can be important signal transducers downstream of polysumoylation. To identify novel polySUMO-binding proteins, we conducted a computational string search with a custom Python script. We found clustered SIMs in another RING domain protein Arkadia/RNF111. Detailed biochemical analysis of the Arkadia SIMs revealed that dominant SIMs in a SIM cluster often contain a pentameric VIDLT ((V/I/L/F/Y)(V/I)DLT) core sequence that is also found in the SIMs in PIAS family E3s and is likely the best-fitted structure for SUMO recognition. This idea led to the identification of additional novel SIM clusters in FLASH/CASP8AP2, C5orf25, and SOBP/JXC1. We suggest that the clustered SIMs in these proteins form distinct SUMO binding domains to recognize diverse forms of protein sumoylation. PMID:23086935

IRAK2 directs stimulus-dependent nuclear export of inflammatory mRNAs

PubMed Central

Yu, Minjia; Qian, Wen; Wang, Han; Zhou, Gao; Chen, Xing; Yang, Hui; Hong, Lingzi; Zhao, Junjie; Qin, Luke; Fukuda, Koichi; Flotho, Annette; Gao, Ji; Dongre, Ashok; Carman, Julie A; Kang, Zizhen; Su, Bing; Kern, Timothy S; Smith, Jonathan D; Hamilton, Thomas A; Melchior, Frauke; Fox, Paul L

2017-01-01

Expression of inflammatory genes is determined in part by post-transcriptional regulation of mRNA metabolism but how stimulus- and transcript-dependent nuclear export influence is poorly understood. Here, we report a novel pathway in which LPS/TLR4 engagement promotes nuclear localization of IRAK2 to facilitate nuclear export of a specific subset of inflammation-related mRNAs for translation in murine macrophages. IRAK2 kinase activity is required for LPS-induced RanBP2-mediated IRAK2 sumoylation and subsequent nuclear translocation. Array analysis showed that an SRSF1-binding motif is enriched in mRNAs dependent on IRAK2 for nuclear export. Nuclear IRAK2 phosphorylates SRSF1 to reduce its binding to target mRNAs, which promotes the RNA binding of the nuclear export adaptor ALYREF and nuclear export receptor Nxf1 loading for the export of the mRNAs. In summary, LPS activates a nuclear function of IRAK2 that facilitates the assembly of nuclear export machinery to export selected inflammatory mRNAs to the cytoplasm for translation. PMID:28990926

IRAK2 directs stimulus-dependent nuclear export of inflammatory mRNAs.

PubMed

Zhou, Hao; Bulek, Katarzyna; Li, Xiao; Herjan, Tomasz; Yu, Minjia; Qian, Wen; Wang, Han; Zhou, Gao; Chen, Xing; Yang, Hui; Hong, Lingzi; Zhao, Junjie; Qin, Luke; Fukuda, Koichi; Flotho, Annette; Gao, Ji; Dongre, Ashok; Carman, Julie A; Kang, Zizhen; Su, Bing; Kern, Timothy S; Smith, Jonathan D; Hamilton, Thomas A; Melchior, Frauke; Fox, Paul L; Li, Xiaoxia

2017-10-09

Expression of inflammatory genes is determined in part by post-transcriptional regulation of mRNA metabolism but how stimulus- and transcript-dependent nuclear export influence is poorly understood. Here, we report a novel pathway in which LPS/TLR4 engagement promotes nuclear localization of IRAK2 to facilitate nuclear export of a specific subset of inflammation-related mRNAs for translation in murine macrophages. IRAK2 kinase activity is required for LPS-induced RanBP2-mediated IRAK2 sumoylation and subsequent nuclear translocation. Array analysis showed that an SRSF1-binding motif is enriched in mRNAs dependent on IRAK2 for nuclear export. Nuclear IRAK2 phosphorylates SRSF1 to reduce its binding to target mRNAs, which promotes the RNA binding of the nuclear export adaptor ALYREF and nuclear export receptor Nxf1 loading for the export of the mRNAs. In summary, LPS activates a nuclear function of IRAK2 that facilitates the assembly of nuclear export machinery to export selected inflammatory mRNAs to the cytoplasm for translation.

Srs2 promotes synthesis-dependent strand annealing by disrupting DNA polymerase δ-extending D-loops

PubMed Central

Liu, Jie; Ede, Christopher; Wright, William D; Gore, Steven K; Jenkins, Shirin S; Freudenthal, Bret D; Todd Washington, M; Veaute, Xavier; Heyer, Wolf-Dietrich

2017-01-01

Synthesis-dependent strand annealing (SDSA) is the preferred mode of homologous recombination in somatic cells leading to an obligatory non-crossover outcome, thus avoiding the potential for chromosomal rearrangements and loss of heterozygosity. Genetic analysis identified the Srs2 helicase as a prime candidate to promote SDSA. Here, we demonstrate that Srs2 disrupts D-loops in an ATP-dependent fashion and with a distinct polarity. Specifically, we partly reconstitute the SDSA pathway using Rad51, Rad54, RPA, RFC, DNA Polymerase δ with different forms of PCNA. Consistent with genetic data showing the requirement for SUMO and PCNA binding for the SDSA role of Srs2, Srs2 displays a slight but significant preference to disrupt extending D-loops over unextended D-loops when SUMOylated PCNA is present, compared to unmodified PCNA or monoubiquitinated PCNA. Our data establish a biochemical mechanism for the role of Srs2 in crossover suppression by promoting SDSA through disruption of extended D-loops. DOI: http://dx.doi.org/10.7554/eLife.22195.001 PMID:28535142

Lysine-Directed Post-translational Modifications of Tau Protein in Alzheimer's Disease and Related Tauopathies

PubMed Central

Kontaxi, Christiana; Piccardo, Pedro; Gill, Andrew C.

2017-01-01

Tau is a microtubule-associated protein responsible mainly for stabilizing the neuronal microtubule network in the brain. Under normal conditions, tau is highly soluble and adopts an “unfolded” conformation. However, it undergoes conformational changes resulting in a less soluble form with weakened microtubule stabilizing properties. Altered tau forms characteristic pathogenic inclusions in Alzheimer's disease and related tauopathies. Although, tau hyperphosphorylation is widely considered to be the major trigger of tau malfunction, tau undergoes several post-translational modifications at lysine residues including acetylation, methylation, ubiquitylation, SUMOylation, and glycation. We are only beginning to define the site-specific impact of each type of lysine modification on tau biology as well as the possible interplay between them, but, like phosphorylation, these modifications are likely to play critical roles in tau's normal and pathobiology. This review summarizes the latest findings focusing on lysine post-translational modifications that occur at both endogenous tau protein and pathological tau forms in AD and other tauopathies. In addition, it highlights the significance of a site-dependent approach of studying tau post-translational modifications under normal and pathological conditions. PMID:28848737

Integrating high-throughput genetic interaction mapping and high-content screening to explore yeast spindle morphogenesis

PubMed Central

Vizeacoumar, Franco J.; van Dyk, Nydia; S.Vizeacoumar, Frederick; Cheung, Vincent; Li, Jingjing; Sydorskyy, Yaroslav; Case, Nicolle; Li, Zhijian; Datti, Alessandro; Nislow, Corey; Raught, Brian; Zhang, Zhaolei; Frey, Brendan; Bloom, Kerry

2010-01-01

We describe the application of a novel screening approach that combines automated yeast genetics, synthetic genetic array (SGA) analysis, and a high-content screening (HCS) system to examine mitotic spindle morphogenesis. We measured numerous spindle and cellular morphological parameters in thousands of single mutants and corresponding sensitized double mutants lacking genes known to be involved in spindle function. We focused on a subset of genes that appear to define a highly conserved mitotic spindle disassembly pathway, which is known to involve Ipl1p, the yeast aurora B kinase, as well as the cell cycle regulatory networks mitotic exit network (MEN) and fourteen early anaphase release (FEAR). We also dissected the function of the kinetochore protein Mcm21p, showing that sumoylation of Mcm21p regulates the enrichment of Ipl1p and other chromosomal passenger proteins to the spindle midzone to mediate spindle disassembly. Although we focused on spindle disassembly in a proof-of-principle study, our integrated HCS-SGA method can be applied to virtually any pathway, making it a powerful means for identifying specific cellular functions. PMID:20065090

A novel robust quantitative Förster resonance energy transfer assay for protease SENP2 kinetics determination against its all natural substrates.

PubMed

Liu, Yan; Shen, Yali; Zheng, Shasha; Liao, Jiayu

2015-12-01

SUMOylation (the process of adding the SUMO [small ubiquitin-like modifier] to substrates) is an important post-translational modification of critical proteins in multiple processes. Sentrin/SUMO-specific proteases (SENPs) act as endopeptidases to process the pre-SUMO or as isopeptidases to deconjugate the SUMO from its substrate. Determining the kinetics of SENPs is important for understanding their activities. Förster resonance energy transfer (FRET) technology has been widely used in biomedical research and is a powerful tool for elucidating protein interactions. In this paper we report a novel quantitative FRET-based protease assay for SENP2 endopeptidase activity that accounts for the self-fluorescent emissions of the donor (CyPet) and the acceptor (YPet). The kinetic parameters, k(cat), K(M), and catalytic efficiency (k(cat)/K(M)) of catalytic domain SENP2 toward pre-SUMO1/2/3, were obtained by this novel design. Although we use SENP2 to demonstrate our method, the general principles of this quantitative FRET-based protease kinetic determination can be readily applied to other proteases.

PPSP: prediction of PK-specific phosphorylation site with Bayesian decision theory.

PubMed

Xue, Yu; Li, Ao; Wang, Lirong; Feng, Huanqing; Yao, Xuebiao

2006-03-20

As a reversible and dynamic post-translational modification (PTM) of proteins, phosphorylation plays essential regulatory roles in a broad spectrum of the biological processes. Although many studies have been contributed on the molecular mechanism of phosphorylation dynamics, the intrinsic feature of substrates specificity is still elusive and remains to be delineated. In this work, we present a novel, versatile and comprehensive program, PPSP (Prediction of PK-specific Phosphorylation site), deployed with approach of Bayesian decision theory (BDT). PPSP could predict the potential phosphorylation sites accurately for approximately 70 PK (Protein Kinase) groups. Compared with four existing tools Scansite, NetPhosK, KinasePhos and GPS, PPSP is more accurate and powerful than these tools. Moreover, PPSP also provides the prediction for many novel PKs, say, TRK, mTOR, SyK and MET/RON, etc. The accuracy of these novel PKs are also satisfying. Taken together, we propose that PPSP could be a potentially powerful tool for the experimentalists who are focusing on phosphorylation substrates with their PK-specific sites identification. Moreover, the BDT strategy could also be a ubiquitous approach for PTMs, such as sumoylation and ubiquitination, etc.

Novel Role for Protein Inhibitor of Activated STAT 4 (PIAS4) in the Restriction of Herpes Simplex Virus 1 by the Cellular Intrinsic Antiviral Immune Response.

PubMed

Conn, Kristen L; Wasson, Peter; McFarlane, Steven; Tong, Lily; Brown, James R; Grant, Kyle G; Domingues, Patricia; Boutell, Chris

2016-05-01

Small ubiquitin-like modifier (SUMO) is used by the intrinsic antiviral immune response to restrict viral pathogens, such as herpes simplex virus 1 (HSV-1). Despite characterization of the host factors that rely on SUMOylation to exert their antiviral effects, the enzymes that mediate these SUMOylation events remain to be defined. We show that unconjugated SUMO levels are largely maintained throughout infection regardless of the presence of ICP0, the HSV-1 SUMO-targeted ubiquitin ligase. Moreover, in the absence of ICP0, high-molecular-weight SUMO-conjugated proteins do not accumulate if HSV-1 DNA does not replicate. These data highlight the continued importance for SUMO signaling throughout infection. We show that the SUMO ligase protein inhibitor of activated STAT 4 (PIAS4) is upregulated during HSV-1 infection and localizes to nuclear domains that contain viral DNA. PIAS4 is recruited to sites associated with HSV-1 genome entry through SUMO interaction motif (SIM)-dependent mechanisms that are destabilized by ICP0. In contrast, PIAS4 accumulates in replication compartments through SIM-independent mechanisms irrespective of ICP0 expression. Depletion of PIAS4 enhances the replication of ICP0-null mutant HSV-1, which is susceptible to restriction by the intrinsic antiviral immune response. The mechanisms of PIAS4-mediated restriction are synergistic with the restriction mechanisms of a characterized intrinsic antiviral factor, promyelocytic leukemia protein, and are antagonized by ICP0. We provide the first evidence that PIAS4 is an intrinsic antiviral factor. This novel role for PIAS4 in intrinsic antiviral immunity contrasts with the known roles of PIAS proteins as suppressors of innate immunity. Posttranslational modifications with small ubiquitin-like modifier (SUMO) proteins regulate multiple aspects of host immunity and viral replication. The protein inhibitor of activated STAT (PIAS) family of SUMO ligases is predominantly associated with the suppression of innate immune signaling. We now identify a unique and contrasting role for PIAS proteins as positive regulators of the intrinsic antiviral immune response to herpes simplex virus 1 (HSV-1) infection. We show that PIAS4 relocalizes to nuclear domains that contain viral DNA throughout infection. Depletion of PIAS4, either alone or in combination with the intrinsic antiviral factor promyelocytic leukemia protein, significantly impairs the intrinsic antiviral immune response to HSV-1 infection. Our data reveal a novel and dynamic role for PIAS4 in the cellular-mediated restriction of herpesviruses and establish a new functional role for the PIAS family of SUMO ligases in the intrinsic antiviral immune response to DNA virus infection. Copyright © 2016 Conn et al.

Novel Role for Protein Inhibitor of Activated STAT 4 (PIAS4) in the Restriction of Herpes Simplex Virus 1 by the Cellular Intrinsic Antiviral Immune Response

PubMed Central

Conn, Kristen L.; Wasson, Peter; McFarlane, Steven; Tong, Lily; Brown, James R.; Grant, Kyle G.; Domingues, Patricia

2016-01-01

ABSTRACT Small ubiquitin-like modifier (SUMO) is used by the intrinsic antiviral immune response to restrict viral pathogens, such as herpes simplex virus 1 (HSV-1). Despite characterization of the host factors that rely on SUMOylation to exert their antiviral effects, the enzymes that mediate these SUMOylation events remain to be defined. We show that unconjugated SUMO levels are largely maintained throughout infection regardless of the presence of ICP0, the HSV-1 SUMO-targeted ubiquitin ligase. Moreover, in the absence of ICP0, high-molecular-weight SUMO-conjugated proteins do not accumulate if HSV-1 DNA does not replicate. These data highlight the continued importance for SUMO signaling throughout infection. We show that the SUMO ligase protein inhibitor of activated STAT 4 (PIAS4) is upregulated during HSV-1 infection and localizes to nuclear domains that contain viral DNA. PIAS4 is recruited to sites associated with HSV-1 genome entry through SUMO interaction motif (SIM)-dependent mechanisms that are destabilized by ICP0. In contrast, PIAS4 accumulates in replication compartments through SIM-independent mechanisms irrespective of ICP0 expression. Depletion of PIAS4 enhances the replication of ICP0-null mutant HSV-1, which is susceptible to restriction by the intrinsic antiviral immune response. The mechanisms of PIAS4-mediated restriction are synergistic with the restriction mechanisms of a characterized intrinsic antiviral factor, promyelocytic leukemia protein, and are antagonized by ICP0. We provide the first evidence that PIAS4 is an intrinsic antiviral factor. This novel role for PIAS4 in intrinsic antiviral immunity contrasts with the known roles of PIAS proteins as suppressors of innate immunity. IMPORTANCE Posttranslational modifications with small ubiquitin-like modifier (SUMO) proteins regulate multiple aspects of host immunity and viral replication. The protein inhibitor of activated STAT (PIAS) family of SUMO ligases is predominantly associated with the suppression of innate immune signaling. We now identify a unique and contrasting role for PIAS proteins as positive regulators of the intrinsic antiviral immune response to herpes simplex virus 1 (HSV-1) infection. We show that PIAS4 relocalizes to nuclear domains that contain viral DNA throughout infection. Depletion of PIAS4, either alone or in combination with the intrinsic antiviral factor promyelocytic leukemia protein, significantly impairs the intrinsic antiviral immune response to HSV-1 infection. Our data reveal a novel and dynamic role for PIAS4 in the cellular-mediated restriction of herpesviruses and establish a new functional role for the PIAS family of SUMO ligases in the intrinsic antiviral immune response to DNA virus infection. PMID:26937035

Urban habitat complexity affects species richness but not environmental filtering of morphologically-diverse ants

PubMed Central

Nash, Michael A.; Christie, Fiona J.; Hahs, Amy K.; Livesley, Stephen J.

2015-01-01

Habitat complexity is a major determinant of structure and diversity of ant assemblages. Following the size-grain hypothesis, smaller ant species are likely to be advantaged in more complex habitats compared to larger species. Habitat complexity can act as an environmental filter based on species size and morphological traits, therefore affecting the overall structure and diversity of ant assemblages. In natural and semi-natural ecosystems, habitat complexity is principally regulated by ecological successions or disturbance such as fire and grazing. Urban ecosystems provide an opportunity to test relationships between habitat, ant assemblage structure and ant traits using novel combinations of habitat complexity generated and sustained by human management. We sampled ant assemblages in low-complexity and high-complexity parks, and high-complexity woodland remnants, hypothesizing that (i) ant abundance and species richness would be higher in high-complexity urban habitats, (ii) ant assemblages would differ between low- and high-complexity habitats and (iii) ants living in high-complexity habitats would be smaller than those living in low-complexity habitats. Contrary to our hypothesis, ant species richness was higher in low-complexity habitats compared to high-complexity habitats. Overall, ant assemblages were significantly different among the habitat complexity types investigated, although ant size and morphology remained the same. Habitat complexity appears to affect the structure of ant assemblages in urban ecosystems as previously observed in natural and semi-natural ecosystems. However, the habitat complexity filter does not seem to be linked to ant morphological traits related to body size. PMID:26528416

Space-based bias of covert visual attention in complex regional pain syndrome.

PubMed

Bultitude, Janet H; Walker, Ian; Spence, Charles

2017-09-01

See Legrain (doi:10.1093/awx188) for a scientific commentary on this article. Some patients with complex regional pain syndrome report that movements of the affected limb are slow, more effortful, and lack automaticity. These symptoms have been likened to the syndrome that sometimes follows brain injury called hemispatial neglect, in which patients exhibit attentional impairments and problems with movements affecting the contralesional side of the body and space. Psychophysical testing of patients with complex regional pain syndrome has found evidence for spatial biases when judging visual targets distanced at 2 m, but not in directions that indicate reduced attention to the affected side. In contrast, when judging visual or tactile stimuli presented on their own body surface, or pictures of hands and feet within arm's reach, patients with complex regional pain syndrome exhibited a bias away from the affected side. What is not yet known is whether patients with complex regional pain syndrome only have biased attention for bodily-specific information in the space within arm's reach, or whether they also show a bias for information that is not associated with the body, suggesting a more generalized attention deficit. Using a temporal order judgement task, we found that patients with complex regional pain syndrome processed visual stimuli more slowly on the affected side (relative to the unaffected side) when the lights were projected onto a blank surface (i.e. when no bodily information was visible), and when the lights were projected onto the dorsal surfaces of their uncrossed hands. However, with the arms crossed (such that the left and right lights projected onto the right and left hands, respectively), patients' responses were no different than controls. These results provide the first demonstration of a generalized attention bias away from the affected side of space in complex regional pain syndrome patients that is not specifically related to bodily information. They also suggest a separate and additional bias of visual attention away from the affected hand. The strength of attention bias was predicted by scores on a self-report measure of body perception distortion; but not by pain intensity, time since diagnosis, or affected body side (left or right). At an individual level, those patients whose upper limbs were most affected had a higher incidence of inattention than those whose lower limbs were most affected. However, at a group level, affected limb (upper or lower) did not predict bias magnitude; nor did three measures designed to assess possible asymmetries in the distribution of movements across space. It is concluded that inattention in near space in complex regional pain syndrome may arise in parallel with a distorted perception of the body.10.1093/brain/awx152_video1awx152media15495542665001. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.

Effects of Task Complexity on L2 Writing Behaviors and Linguistic Complexity

ERIC Educational Resources Information Center

Révész, Andrea; Kourtali, Nektaria-Efstathia; Mazgutova, Diana

2017-01-01

This study investigated whether task complexity influences second language (L2) writers' fluency, pausing, and revision behaviors and the cognitive processes underlying these behaviors; whether task complexity affects linguistic complexity of written output; and whether relationships between writing behaviors and linguistic complexity are…

Finding of No Significant Impact and Finding of No Practicable Alternative Construction of a Warehouse Complex MacDill Air Force Base, Florida

DTIC Science & Technology

2010-05-31

that Federal agencies identify and assess environmental health and safety risks that might disproportionately affect children. The Proposed Action...extra water is sent to one irrigation field near Golf Course Avenue and Affected Environment Environmental Assessment for Warehouse Complex...the area . Environmental Consequences Environmental Assessment for Warehouse Complex MacDill AFB, Florida FEBRUARY 2010 4-15 FINAL Figure

Cognitive and Affective Processes Underlying Career Change

ERIC Educational Resources Information Center

Muja, Naser; Appelbaum, Steven H.

2012-01-01

Purpose: Aligning social identity and career identity has become increasingly complex due to growth in the pursuit of meaningful careers that offer very long-term personal satisfaction and stability. This paper aims to explore the complex cognitive and affective thought process involved in the conscious planning of voluntary career change.…

Spatiotemporal dynamics of black-tailed prairie dog colonies affected by plague

USGS Publications Warehouse

Augustine, D.J.; Matchett, M.R.; Toombs, T.P.; Cully, J.F.; Johnson, T.L.; Sidle, John G.

2008-01-01

Black-tailed prairie dogs (Cynomys ludovicianus) are a key component of the disturbance regime in semi-arid grasslands of central North America. Many studies have compared community and ecosystem characteristics on prairie dog colonies to grasslands without prairie dogs, but little is known about landscape-scale patterns of disturbance that prairie dog colony complexes may impose on grasslands over long time periods. We examined spatiotemporal dynamics in two prairie dog colony complexes in southeastern Colorado (Comanche) and northcentral Montana (Phillips County) that have been strongly influenced by plague, and compared them to a complex unaffected by plague in northwestern Nebraska (Oglala). Both plague-affected complexes exhibited substantial spatiotemporal variability in the area occupied during a decade, in contrast to the stability of colonies in the Oglala complex. However, the plague-affected complexes differed in spatial patterns of colony movement. Colonies in the Comanche complex in shortgrass steppe shifted locations over a decade. Only 10% of the area occupied in 1995 was still occupied by prairie dogs in 2006. In 2005 and 2006 respectively, 74 and 83% of the total area of the Comanche complex occurred in locations that were not occupied in 1995, and only 1% of the complex was occupied continuously over a decade. In contrast, prairie dogs in the Phillips County complex in mixed-grass prairie and sagebrush steppe primarily recolonized previously occupied areas after plague-induced colony declines. In Phillips County, 62% of the area occupied in 1993 was also occupied by prairie dogs in 2004, and 12% of the complex was occupied continuously over a decade. Our results indicate that plague accelerates spatiotemporal movement of prairie dog colonies, and have significant implications for landscape-scale effects of prairie dog disturbance on grassland composition and productivity. These findings highlight the need to combine landscape-scale measures of habitat suitability with long-term measures of colony locations to understand the role of plague-affected prairie dogs as a grassland disturbance process. ?? 2007 Springer Science+Business Media B.V.

Mitochondrial proteomic profile of complex IV deficiency fibroblasts: rearrangement of oxidative phosphorylation complex/supercomplex and other metabolic pathways.

PubMed

Salvador-Severo, Karina; Gómez-Caudillo, Leopoldo; Quezada, Héctor; García-Trejo, José de Jesús; Cárdenas-Conejo, Alan; Vázquez-Memije, Martha Elisa; Minauro-Sanmiguel, Fernando

Mitochondriopathies are multisystem diseases affecting the oxidative phosphorylation (OXPHOS) system. Skin fibroblasts are a good model for the study of these diseases. Fibroblasts with a complex IV mitochondriopathy were used to determine the molecular mechanism and the main affected functions in this disease. Skin fibroblast were grown to assure disease phenotype. Mitochondria were isolated from these cells and their proteome extracted for protein identification. Identified proteins were validated with the MitoMiner database. Disease phenotype was corroborated on skin fibroblasts, which presented a complex IV defect. The mitochondrial proteome of these cells showed that the most affected proteins belonged to the OXPHOS system, mainly to the complexes that form supercomplexes or respirosomes (I, III, IV, and V). Defects in complex IV seemed to be due to assembly issues, which might prevent supercomplexes formation and efficient substrate channeling. It was also found that this mitochondriopathy affects other processes that are related to DNA genetic information flow (replication, transcription, and translation) as well as beta oxidation and tricarboxylic acid cycle. These data, as a whole, could be used for the better stratification of these diseases, as well as to optimize management and treatment options. Copyright © 2017 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Modification of nuclear PML protein by SUMO-1 regulates Fas-induced apoptosis in rheumatoid arthritis synovial fibroblasts

PubMed Central

Meinecke, Ingmar; Cinski, Antje; Baier, Anja; Peters, Marvin A.; Dankbar, Berno; Wille, Aline; Drynda, Andreas; Mendoza, Heidi; Gay, Renate E.; Hay, Ronald T.; Ink, Barbara; Gay, Steffen; Pap, Thomas

2007-01-01

The small ubiquitin-like modifier (SUMO)-1 is an important posttranslational regulator of different signaling pathways and involved in the formation of promyelocytic leukemia (PML) protein nuclear bodies (NBs). Overexpression of SUMO-1 has been associated with alterations in apoptosis, but the underlying mechanisms and their relevance for human diseases are not clear. Here, we show that the increased expression of SUMO-1 in rheumatoid arthritis (RA) synovial fibroblasts (SFs) contributes to the resistance of these cells against Fas-induced apoptosis through increased SUMOylation of nuclear PML protein and increased recruitment of the transcriptional repressor DAXX to PML NBs. We also show that the nuclear SUMO-protease SENP1, which is found at lower levels in RA SFs, can revert the apoptosis-inhibiting effects of SUMO-1 by releasing DAXX from PML NBs. Our findings indicate that in RA SFs overexpression of SENP1 can alter the SUMO-1-mediated recruitment of DAXX to PML NBs, thus influencing the proapoptotic effects of DAXX. Accumulation of DAXX in PML NBs by SUMO-1 may, therefore, contribute to the pathogenesis of inflammatory disorders. PMID:17360386

Arabidopsis TCP Transcription Factors Interact with the SUMO Conjugating Machinery in Nuclear Foci

PubMed Central

Mazur, Magdalena J.; Spears, Benjamin J.; Djajasaputra, André; van der Gragt, Michelle; Vlachakis, Georgios; Beerens, Bas; Gassmann, Walter; van den Burg, Harrold A.

2017-01-01

In Arabidopsis more than 400 proteins have been identified as SUMO targets, both in vivo and in vitro. Among others, transcription factors (TFs) are common targets for SUMO conjugation. Here we aimed to exhaustively screen for TFs that interact with the SUMO machinery using an arrayed yeast two-hybrid library containing more than 1,100 TFs. We identified 76 interactors that foremost interact with the SUMO conjugation enzyme SCE1 and/or the SUMO E3 ligase SIZ1. These interactors belong to various TF families, which control a wide range of processes in plant development and stress signaling. Amongst these interactors, the TCP family was overrepresented with several TCPs interacting with different proteins of the SUMO conjugation cycle. For a subset of these TCPs we confirmed that the catalytic site of SCE1 is essential for this interaction. In agreement, TCP1, TCP3, TCP8, TCP14, and TCP15 were readily SUMO modified in an E. coli sumoylation assay. Strikingly, these TCP-SCE1 interactions were found to redistribute these TCPs into nuclear foci/speckles, suggesting that these TCP foci represent sites for SUMO (conjugation) activity. PMID:29250092

Tight regulation of a timed nuclear import wave of EKLF by PKCθ and FOE during Pro-E to Baso-E transition.

PubMed

Shyu, Yu-Chiau; Lee, Tung-Liang; Chen, Xin; Hsu, Pang-Hung; Wen, Shau-Ching; Liaw, Yi-Wei; Lu, Chi-Huan; Hsu, Po-Yen; Lu, Mu-Jie; Hwang, JauLang; Tsai, Ming-Daw; Hwang, Ming-Jing; Chen, Jim-Ray; Shen, Che-Kun James

2014-02-24

Erythropoiesis is a highly regulated process during which BFU-E are differentiated into RBCs through CFU-E, Pro-E, PolyCh-E, OrthoCh-E, and reticulocyte stages. Uniquely, most erythroid-specific genes are activated during the Pro-E to Baso-E transition. We show that a wave of nuclear import of the erythroid-specific transcription factor EKLF occurs during the Pro-E to Baso-E transition. We further demonstrate that this wave results from a series of finely tuned events, including timed activation of PKCθ, phosphorylation of EKLF at S68 by P-PKCθ(S676), and sumoylation of EKLF at K74. The latter EKLF modifications modulate its interactions with a cytoplasmic ankyrin-repeat-protein FOE and importinβ1, respectively. The role of FOE in the control of EKLF nuclear import is further supported by analysis of the subcellular distribution patterns of EKLF in FOE-knockout mice. This study reveals the regulatory mechanisms of the nuclear import of EKLF, which may also be utilized in the nuclear import of other factors. Copyright © 2014 Elsevier Inc. All rights reserved.

Hepatocyte Growth Factor Improves the Therapeutic Efficacy of Human Bone Marrow Mesenchymal Stem Cells via RAD51.

PubMed

Lee, Eun Ju; Hwang, Injoo; Lee, Ji Yeon; Park, Jong Nam; Kim, Keun Cheon; Kim, Gi-Hwan; Kang, Chang-Mo; Kim, Irene; Lee, Seo-Yeon; Kim, Hyo-Soo

2018-03-07

Human embryonic stem cell-derived mesenchymal stem cells (hE-MSCs) have greater proliferative capacity than other human mesenchymal stem cells (hMSCs), suggesting that they may have wider applications in regenerative cellular therapy. In this study, to uncover the anti-senescence mechanism in hE-MSCs, we compared hE-MSCs with adult bone marrow (hBM-MSCs) and found that hepatocyte growth factor (HGF) was more abundantly expressed in hE-MSCs than in hBM-MSCs and that it induced the transcription of RAD51 and facilitated its SUMOylation at K70. RAD51 induction/modification by HGF not only increased telomere length but also increased mtDNA replication, leading to increased ATP generation. Moreover, HGF-treated hBM-MSCs showed significantly better therapeutic efficacy than naive hBM-MSCs. Together, the data suggest that the RAD51-mediated effects of HGF prevent hMSC senescence by promoting telomere lengthening and inducing mtDNA replication and function, which opens the prospect of developing novel therapies for liver disease. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

Cross Talk between PML and p53 during Poliovirus Infection: Implications for Antiviral Defense

PubMed Central

Pampin, Mathieu; Simonin, Yannick; Blondel, Bruno; Percherancier, Yann; Chelbi-Alix, Mounira K.

2006-01-01

PML nuclear bodies (NBs) are dynamic intranuclear structures harboring numerous transiently or permanently localized proteins. PML, the NBs' organizer, is directly induced by interferon, and its expression is critical for antiviral host defense. We describe herein the molecular events following poliovirus infection that lead to PML-dependent p53 activation and protection against virus infection. Poliovirus infection induces PML phosphorylation through the extracellular signal-regulated kinase pathway, increases PML SUMOylation, and induces its transfer from the nucleoplasm to the nuclear matrix. These events result in the recruitment of p53 to PML NBs, p53 phosphorylation on Ser15, and activation of p53 target genes leading to the induction of apoptosis. Moreover, the knock-down of p53 by small interfering RNA results in higher poliovirus replication, suggesting that p53 participates in antiviral defense. This effect, which requires the presence of PML, is transient since poliovirus targets p53 by inducing its degradation in a proteasome- and MDM2-dependent manner. Our results provide evidence of how poliovirus counteracts p53 antiviral activity by regulating PML and NBs, thus leading to p53 degradation. PMID:16912307

Cross talk between PML and p53 during poliovirus infection: implications for antiviral defense.

PubMed

Pampin, Mathieu; Simonin, Yannick; Blondel, Bruno; Percherancier, Yann; Chelbi-Alix, Mounira K

2006-09-01

PML nuclear bodies (NBs) are dynamic intranuclear structures harboring numerous transiently or permanently localized proteins. PML, the NBs' organizer, is directly induced by interferon, and its expression is critical for antiviral host defense. We describe herein the molecular events following poliovirus infection that lead to PML-dependent p53 activation and protection against virus infection. Poliovirus infection induces PML phosphorylation through the extracellular signal-regulated kinase pathway, increases PML SUMOylation, and induces its transfer from the nucleoplasm to the nuclear matrix. These events result in the recruitment of p53 to PML NBs, p53 phosphorylation on Ser15, and activation of p53 target genes leading to the induction of apoptosis. Moreover, the knock-down of p53 by small interfering RNA results in higher poliovirus replication, suggesting that p53 participates in antiviral defense. This effect, which requires the presence of PML, is transient since poliovirus targets p53 by inducing its degradation in a proteasome- and MDM2-dependent manner. Our results provide evidence of how poliovirus counteracts p53 antiviral activity by regulating PML and NBs, thus leading to p53 degradation.

Circadian clock component REV-ERBα controls homeostatic regulation of pulmonary inflammation.

PubMed

Pariollaud, Marie; Gibbs, Julie E; Hopwood, Thomas W; Brown, Sheila; Begley, Nicola; Vonslow, Ryan; Poolman, Toryn; Guo, Baoqiang; Saer, Ben; Jones, D Heulyn; Tellam, James P; Bresciani, Stefano; Tomkinson, Nicholas Co; Wojno-Picon, Justyna; Cooper, Anthony Wj; Daniels, Dion A; Trump, Ryan P; Grant, Daniel; Zuercher, William; Willson, Timothy M; MacDonald, Andrew S; Bolognese, Brian; Podolin, Patricia L; Sanchez, Yolanda; Loudon, Andrew Si; Ray, David W

2018-06-01

Recent studies reveal that airway epithelial cells are critical pulmonary circadian pacemaker cells, mediating rhythmic inflammatory responses. Using mouse models, we now identify the rhythmic circadian repressor REV-ERBα as essential to the mechanism coupling the pulmonary clock to innate immunity, involving both myeloid and bronchial epithelial cells in temporal gating and determining amplitude of response to inhaled endotoxin. Dual mutation of REV-ERBα and its paralog REV-ERBβ in bronchial epithelia further augmented inflammatory responses and chemokine activation, but also initiated a basal inflammatory state, revealing a critical homeostatic role for REV-ERB proteins in the suppression of the endogenous proinflammatory mechanism in unchallenged cells. However, REV-ERBα plays the dominant role, as deletion of REV-ERBβ alone had no impact on inflammatory responses. In turn, inflammatory challenges cause striking changes in stability and degradation of REV-ERBα protein, driven by SUMOylation and ubiquitination. We developed a novel selective oxazole-based inverse agonist of REV-ERB, which protects REV-ERBα protein from degradation, and used this to reveal how proinflammatory cytokines trigger rapid degradation of REV-ERBα in the elaboration of an inflammatory response. Thus, dynamic changes in stability of REV-ERBα protein couple the core clock to innate immunity.

Role of Desumoylation in the Development of Prostate Cancer1

PubMed Central

Cheng, Jinke; Bawa, Tasneem; Lee, Peng; Gong, Limin; Yeh, Edward T. H

2006-01-01

Abstract SUMO is a novel ubiquitin-like protein that can covalently modify a large number of nuclear proteins. SUMO modification has emerged as an important regulatory mechanism for protein function and localization. Sumoylation is a dynamic process that is mediated by activating (E1), conjugating (E2), and ligating (E3) enzymes and is readily reversed by a family of SUMO-specific proteases (SENPs). Since SUMO was discovered 10 years ago, the biologic contribution of this posttranslational modification has remained unclear. In this review, we report that SENP1, a member of the SENP family, is overexpressed in human prostate cancer specimens. The induction of SENP1 is observed with the chronic exposure of prostate cancer cells to androgen and/or interleukin (IL) 6. SENP1 upregulation modulates the transcriptional activity of androgen receptors (ARs) and c-Jun, as well as cyclin D1 expression. Initial in vivo data from transgenic mice indicate that overexpression of SENP1 in the prostate leads to the development of prostatic intraepithelial neoplasia at an early age. Collectively, these studies indicate that overexpression of SENP1 is associated with prostate cancer development. PMID:16925949

Identification of Factors That Affect Software Complexity.

ERIC Educational Resources Information Center

Kaiser, Javaid

A survey of computer scientists was conducted to identify factors that affect software complexity. A total of 160 items were selected from the literature to include in a questionnaire sent to 425 individuals who were employees of computer-related businesses in Lawrence and Kansas City. The items were grouped into nine categories called system…

Environmental Factors Affecting Computer Assisted Language Learning Success: A Complex Dynamic Systems Conceptual Model

ERIC Educational Resources Information Center

Marek, Michael W.; Wu, Wen-Chi Vivian

2014-01-01

This conceptual, interdisciplinary inquiry explores Complex Dynamic Systems as the concept relates to the internal and external environmental factors affecting computer assisted language learning (CALL). Based on the results obtained by de Rosnay ["World Futures: The Journal of General Evolution", 67(4/5), 304-315 (2011)], who observed…

78 FR 58316 - Complex Issues in Developing Medical Devices for Pediatric Patients Affected by Rare Diseases...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-23

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-1073] Complex Issues in Developing Medical Devices for Pediatric Patients Affected by Rare Diseases; Public Workshop; Request for Comments AGENCY: Food and Drug Administration, HHS. ACTION: Notice of public workshop...

Evidence of major genes affecting stress response in rainbow trout using Bayesian methods of complex segregation analysis

USDA-ARS?s Scientific Manuscript database

As a first step towards the genetic mapping of quantitative trait loci (QTL) affecting stress response variation in rainbow trout, we performed complex segregation analyses (CSA) fitting mixed inheritance models of plasma cortisol using Bayesian methods in large full-sib families of rainbow trout. ...

Cryptic breakpoint identified by whole-genome mate-pair sequencing in a rare paternally inherited complex chromosomal rearrangement.

PubMed

Aristidou, Constantia; Theodosiou, Athina; Ketoni, Andria; Bak, Mads; Mehrjouy, Mana M; Tommerup, Niels; Sismani, Carolina

2018-01-01

Precise characterization of apparently balanced complex chromosomal rearrangements in non-affected individuals is crucial as they may result in reproductive failure, recurrent miscarriages or affected offspring. We present a family, where the non-affected father and daughter were found, using FISH and karyotyping, to be carriers of a three-way complex chromosomal rearrangement [t(6;7;10)(q16.2;q34;q26.1), de novo in the father]. The family suffered from two stillbirths, one miscarriage, and has a son with severe intellectual disability. In the present study, the family was revisited using whole-genome mate-pair sequencing. Interestingly, whole-genome mate-pair sequencing revealed a cryptic breakpoint on derivative (der) chromosome 6 rendering the rearrangement even more complex. FISH using a chromosome (chr) 6 custom-designed probe and a chr10 control probe confirmed that the interstitial chr6 segment, created by the two chr6 breakpoints, was translocated onto der(10). Breakpoints were successfully validated with Sanger sequencing, and small imbalances as well as microhomology were identified. Finally, the complex chromosomal rearrangement breakpoints disrupted the SIM1 , GRIK2 , CNTNAP2 , and PTPRE genes without causing any phenotype development. In contrast to the majority of maternally transmitted complex chromosomal rearrangement cases, our study investigated a rare case where a complex chromosomal rearrangement, which most probably resulted from a Type IV hexavalent during the pachytene stage of meiosis I, was stably transmitted from a fertile father to his non-affected daughter. Whole-genome mate-pair sequencing proved highly successful in identifying cryptic complexity, which consequently provided further insight into the meiotic segregation of chromosomes and the increased reproductive risk in individuals carrying the specific complex chromosomal rearrangement. We propose that such complex rearrangements should be characterized in detail using a combination of conventional cytogenetic and NGS-based approaches to aid in better prenatal preimplantation genetic diagnosis and counseling in couples with reproductive problems.

Phonetic complexity and stuttering in Spanish

PubMed Central

Howell, Peter; Au-Yeung, James

2007-01-01

The current study investigated whether phonetic complexity affected stuttering rate for Spanish speakers. The speakers were assigned to three age groups (6-11, 12-17 and 18 years plus) that were similar to those used in an earlier study on English. The analysis was performed using Jakielski's (1998) Index of Phonetic Complexity (IPC) scheme in which each word is given an IPC score based on the number of complex attributes it includes for each of eight factors. Stuttering on function words for Spanish did not correlate with IPC score for any age group. This mirrors the finding for English that stuttering on these words is not affected by phonetic complexity. The IPC scores of content words correlated positively with stuttering rate for 6-11 year old and adult speakers. Comparison was made between the languages to establish whether or not experience with the factors determines the problem they pose for speakers (revealed by differences in stuttering rate). Evidence was obtained that four factors found to be important determinants of stuttering on content words in English for speakers aged 12 and above, also affected Spanish speakers. This occurred despite large differences in frequency of usage of these factors. It is concluded that phonetic factors affect stuttering rate irrespective of a speaker's experience with that factor. PMID:17364620

Phonetic complexity and stuttering in Spanish.

PubMed

Howell, Peter; Au-Yeung, James

2007-02-01

The current study investigated whether phonetic complexity affected stuttering rate for Spanish speakers. The speakers were assigned to three age groups (6-11, 12-17 and 18-years plus) that were similar to those used in an earlier study on English. The analysis was performed using Jakielski's Index of Phonetic Complexity (IPC) scheme in which each word is given an IPC score based on the number of complex attributes it includes for each of eight factors. Stuttering on function words for Spanish did not correlate with IPC score for any age group. This mirrors the finding for English that stuttering on these words is not affected by phonetic complexity. The IPC scores of content words correlated positively with stuttering rate for 6-11-year-old and adult speakers. Comparison was made between the languages to establish whether or not experience with the factors determines the problem they pose for speakers (revealed by differences in stuttering rate). Evidence was obtained that four factors found to be important determinants of stuttering on content words in English for speakers aged 12 and above, also affected Spanish speakers. This occurred despite large differences in frequency of usage of these factors. It is concluded that phonetic factors affect stuttering rate irrespective of a speaker's experience with that factor.

Accuracy of travel time distribution (TTD) models as affected by TTD complexity, observation errors, and model and tracer selection

USGS Publications Warehouse

Green, Christopher T.; Zhang, Yong; Jurgens, Bryant C.; Starn, J. Jeffrey; Landon, Matthew K.

2014-01-01

Analytical models of the travel time distribution (TTD) from a source area to a sample location are often used to estimate groundwater ages and solute concentration trends. The accuracies of these models are not well known for geologically complex aquifers. In this study, synthetic datasets were used to quantify the accuracy of four analytical TTD models as affected by TTD complexity, observation errors, model selection, and tracer selection. Synthetic TTDs and tracer data were generated from existing numerical models with complex hydrofacies distributions for one public-supply well and 14 monitoring wells in the Central Valley, California. Analytical TTD models were calibrated to synthetic tracer data, and prediction errors were determined for estimates of TTDs and conservative tracer (NO3−) concentrations. Analytical models included a new, scale-dependent dispersivity model (SDM) for two-dimensional transport from the watertable to a well, and three other established analytical models. The relative influence of the error sources (TTD complexity, observation error, model selection, and tracer selection) depended on the type of prediction. Geological complexity gave rise to complex TTDs in monitoring wells that strongly affected errors of the estimated TTDs. However, prediction errors for NO3− and median age depended more on tracer concentration errors. The SDM tended to give the most accurate estimates of the vertical velocity and other predictions, although TTD model selection had minor effects overall. Adding tracers improved predictions if the new tracers had different input histories. Studies using TTD models should focus on the factors that most strongly affect the desired predictions.

The Use of AlphaScreen Technology in HTS: Current Status

PubMed Central

Eglen, Richard M; Reisine, Terry; Roby, Philippe; Rouleau, Nathalie; Illy, Chantal; Bossé, Roger; Bielefeld, Martina

2008-01-01

AlphaScreen (Amplified Luminescent Proximity Homogeneous Assay Screen) is versatile assay technology developed to measuring analytes using a homogenous protocol. This technology is an example of a bead-based proximity assay and was developed from a diagnostic assay technology known as LOCI (Luminescent Oxygen Channeling Assay). Here, singlet oxygen molecules, generated by high energy irradiation of Donor beads, travel over a constrained distance (approx. 200 nm) to Acceptor beads. This results in excitation of a cascading series of chemical reactions, ultimately causing generation of a chemiluminescent signal. In the past decade, a wide variety of applications has been reported, ranging from detection of analytes involved in cell signaling, including protein:protein, protein:peptide, protein:small molecule or peptide:peptide interactions. Numerous homogeneous HTS-optimized assays have been reported using the approach, including generation of second messengers (such as accumulation of cyclic AMP, cyclic GMP, inositol [1, 4, 5] trisphosphate or phosphorylated ERK) from liganded GPCRs or tyrosine kinase receptors, post-translational modification of proteins (such as proteolytic cleavage, phosphorylation, ubiquination and sumoylation) as well as protein-protein and protein-nucleic acid interactions. Recently, the basic AlphaScreen technology was extended in that the chemistry of the Acceptor bead was modified such that emitted light is more intense and spectrally defined, thereby markedly reducing interference from biological fluid matrices (such as trace hemolysis in serum and plasma). In this format, referred to as AlphaLISA, it provides an alternative technology to classical ELISA assays and is suitable for high throughput automated fluid dispensing and detection systems. Collectively, AlphaScreen and AlphaLISA technologies provide a facile assay platform with which one can quantitate complex cellular processes using simple no-wash microtiter plate based assays. They provide the means by which large compound libraries can be screened in a high throughput fashion at a diverse range of therapeutically important targets, often not readily undertaken using other homogeneous assay technologies. This review assesses the current status of the technology in drug discovery, in general, and high throughput screening (HTS), in particular. PMID:20161822

Evasion of interferon responses by Ebola and Marburg viruses.

PubMed

Basler, Christopher F; Amarasinghe, Gaya K

2009-09-01

The filoviruses, Ebola virus (EBOV) and Marburg virus (MARV), cause frequently lethal viral hemorrhagic fever. These infections induce potent cytokine production, yet these host responses fail to prevent systemic virus replication. Consistent with this, filoviruses have been found to encode proteins VP35 and VP24 that block host interferon (IFN)-alpha/beta production and inhibit signaling downstream of the IFN-alpha/beta and the IFN-gamma receptors, respectively. VP35, which is a component of the viral nucleocapsid complex and plays an essential role in viral RNA synthesis, acts as a pseudosubstrate for the cellular kinases IKK-epsilon and TBK-1, which phosphorylate and activate interferon regulatory factor 3 (IRF-3) and interferon regulatory factor 7 (IRF-7). VP35 also promotes SUMOylation of IRF-7, repressing IFN gene transcription. In addition, VP35 is a dsRNA-binding protein, and mutations that disrupt dsRNA binding impair VP35 IFN-antagonist activity while leaving its RNA replication functions intact. The phenotypes of recombinant EBOV bearing mutant VP35s unable to inhibit IFN-alpha/beta demonstrate that VP35 IFN-antagonist activity is critical for full virulence of these lethal pathogens. The structure of the VP35 dsRNA-binding domain, which has recently become available, is expected to provide insight into how VP35 IFN-antagonist and dsRNA-binding functions are related. The EBOV VP24 protein inhibits IFN signaling through an interaction with select host cell karyopherin-alpha proteins, preventing the nuclear import of otherwise activated STAT1. It remains to be determined to what extent VP24 may also modulate the nuclear import of other host cell factors and to what extent this may influence the outcome of infection. Notably, the Marburg virus VP24 protein does not detectably block STAT1 nuclear import, and, unlike EBOV, MARV infection inhibits STAT1 and STAT2 phosphorylation. Thus, despite their similarities, there are fundamental differences by which these deadly viruses counteract the IFN system. It will be of interest to determine how these differences influence pathogenesis.

Attempt to generalize fractional-order electric elements to complex-order ones

NASA Astrophysics Data System (ADS)

Si, Gangquan; Diao, Lijie; Zhu, Jianwei; Lei, Yuhang; Zhang, Yanbin

2017-06-01

The complex derivative {D}α +/- {{j}β }, with α, β \\in R+ is a generalization of the concept of integer derivative, where α=1, β=0. Fractional-order electric elements and circuits are becoming more and more attractive. In this paper, the complex-order electric elements concept is proposed for the first time, and the complex-order elements are modeled and analyzed. Some interesting phenomena are found that the real part of the order affects the phase of output signal, and the imaginary part affects the amplitude for both the complex-order capacitor and complex-order memristor. More interesting is that the complex-order capacitor can do well at the time of fitting electrochemistry impedance spectra. The complex-order memristor is also analyzed. The area inside the hysteresis loops increases with the increasing of the imaginary part of the order and decreases with the increasing of the real part. Some complex case of complex-order memristors hysteresis loops are analyzed at last, whose loop has touching points beyond the origin of the coordinate system.

Genetics Home Reference: seasonal affective disorder

MedlinePlus

... seasonal affective disorder are complex. A shortage of sunlight contributes to the development of the disorder in the fall and winter months, and too much sunlight is associated with seasonal affective disorder in the ...

The Complex Relation between Bullying, Victimization, Acceptance, and Rejection: Giving Special Attention to Status, Affection, and Sex Differences

ERIC Educational Resources Information Center

Veenstra, Rene; Lindenberg, Siegwart; Munniksma, Anke; Dijkstra, Jan Kornelis

2010-01-01

To understand the complex nature of bullies' acceptance and rejection, this article considered goal-framing effects of status and affection as they relate to the gender of the bully (male vs. female bullies), the target (male vs. female victims), and the evaluator (acceptance and rejection from male vs. female classmates). The hypotheses were…

Affective evaluation of food images according to stimulus and subject characteristics.

PubMed

Padulo, C; Carlucci, L; Marzoli, D; Manippa, V; Tommasi, L; Saggino, A; Puglisi-Allegra, S; Brancucci, A

2018-04-17

The food-rich environment in which we live makes the regulation of food choices a very complex phenomenon determined by many factors, as well as their interactions. Much evidence suggests that the sensory perception of food can be considered as a central factor affecting individual food choices. Despite this, the approaches used to study the various food aspects usually do not distinguish between different types of food. In the present study, a large and heterogeneous sample of 1149 participants aged 7-90 years was asked to judge food images that were labelled differently (i.e. Raw versus Cooked, Natural versus Transformed and Simple versus Complex) with respect to arousal, valence, typicality and familiarity. We observed that, across food dimensions (i.e., Raw versus Cooked, Natural versus Transformed and Simple versus Complex), arousal, valence and typicality judgments were principally affected by a subjective hunger level and gender (and their interaction) and, to a lesser extent, by age. As a whole, our findings suggest that the level of transformation (which includes cooking) and the complexity of a foodstuff could at least partially affect food processing, entailing that future research should also address these features. © 2018 The British Dietetic Association Ltd.

Identification of amino acids that promote specific and rigid TAR RNA-tat protein complex formation.

PubMed

Edwards, Thomas E; Robinson, Bruce H; Sigurdsson, Snorri Th

2005-03-01

The Tat protein and the transactivation responsive (TAR) RNA form an essential complex in the HIV lifecycle, and mutations in the basic region of the Tat protein alter this RNA-protein molecular recognition. Here, EPR spectroscopy was used to identify amino acids, flanking an essential arginine of the Tat protein, which contribute to specific and rigid TAR-Tat complex formation by monitoring changes in the mobility of nitroxide spin-labeled TAR RNA nucleotides upon binding. Arginine to lysine N-terminal mutations did not affect TAR RNA interfacial dynamics. In contrast, C-terminal point mutations, R56 in particular, affected the mobility of nucleotides U23 and U38, which are involved in a base-triple interaction in the complex. This report highlights the role of dynamics in specific molecular complex formation and demonstrates the ability of EPR spectroscopy to study interfacial dynamics of macromolecular complexes.

Should I go with my gut? Investigating the benefits of emotion-focused decision making.

PubMed

Mikels, Joseph A; Maglio, Sam J; Reed, Andrew E; Kaplowitz, Lee J

2011-08-01

Deliberative decision strategies have historically been considered the surest path to sound decisions; however, recent evidence and theory suggest that affective strategies may be equally as effective. In four experiments we examined conditions under which affective versus deliberative decision strategies might result in higher decision quality. While consciously focusing on feelings versus details, participants made choices that varied in complexity, in extent of subsequent conscious deliberation allowed, and in domain. Results indicate that focusing on feelings versus details led to superior objective and subjective decision quality for complex decisions. However, when using a feeling-focused approach, subsequent deliberation after encoding resulted in reduced choice quality. These results suggest that affective decision strategies may be more effective relative to deliberative strategies for certain complex decisions. 2011 APA, all rights reserved

Interleukin-8 responses of multi-layer gingival epithelia to subgingival biofilms: role of the "red complex" species.

PubMed

Belibasakis, Georgios N; Thurnheer, Thomas; Bostanci, Nagihan

2013-01-01

Periodontitis is an infectious inflammatory disease that results in the destruction of the tooth-supporting (periodontal) tissues. The Gram-negative anaerobic species Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, (also known as the "red complex" species) are highly associated with subgingival biofilms at periodontitis-affected sites. A major chemokine produced by the gingival epithelium in response to biofilm challenge, is interleukin (IL)-8. The aim of this in vitro study was to investigate the relative effect of the "red complex" species as constituents of subgingival biofilms, on the regulation of IL-8 by gingival epithelia. Multi-layered organotypic human gingival epithelial cultures were challenged with a 10-species in vitro subgingival biofilm model, or its 7-species variant, excluding the "red complex". IL-8 gene expression and secretion analyses were performed by qPCR and ELISA, respectively. After 3 h, both biofilms up-regulated IL-8 gene expression, but the presence of the "red complex" resulted in 3-fold greater response. IL-8 secretion was also up-regulated by both biofilms, with no differences between them. After 24 h, the 10-species biofilm reduced IL-8 secretion to 50% of the control, but this was not affected when the "red complex" was absent. In conclusion, as part of biofilms, "red complex" species differentially regulate IL-8 in gingival epithelia, potentially affecting the chemotactic responses of the tissue.

Examining Complexity across Domains: Relating Subjective and Objective Measures of Affective Environmental Scenes, Paintings and Music

PubMed Central

Marin, Manuela M.; Leder, Helmut

2013-01-01

Subjective complexity has been found to be related to hedonic measures of preference, pleasantness and beauty, but there is no consensus about the nature of this relationship in the visual and musical domains. Moreover, the affective content of stimuli has been largely neglected so far in the study of complexity but is crucial in many everyday contexts and in aesthetic experiences. We thus propose a cross-domain approach that acknowledges the multidimensional nature of complexity and that uses a wide range of objective complexity measures combined with subjective ratings. In four experiments, we employed pictures of affective environmental scenes, representational paintings, and Romantic solo and chamber music excerpts. Stimuli were pre-selected to vary in emotional content (pleasantness and arousal) and complexity (low versus high number of elements). For each set of stimuli, in a between-subjects design, ratings of familiarity, complexity, pleasantness and arousal were obtained for a presentation time of 25 s from 152 participants. In line with Berlyne’s collative-motivation model, statistical analyses controlling for familiarity revealed a positive relationship between subjective complexity and arousal, and the highest correlations were observed for musical stimuli. Evidence for a mediating role of arousal in the complexity-pleasantness relationship was demonstrated in all experiments, but was only significant for females with regard to music. The direction and strength of the linear relationship between complexity and pleasantness depended on the stimulus type and gender. For environmental scenes, the root mean square contrast measures and measures of compressed file size correlated best with subjective complexity, whereas only edge detection based on phase congruency yielded equivalent results for representational paintings. Measures of compressed file size and event density also showed positive correlations with complexity and arousal in music, which is relevant for the discussion on which aspects of complexity are domain-specific and which are domain-general. PMID:23977295

Examining complexity across domains: relating subjective and objective measures of affective environmental scenes, paintings and music.

PubMed

Marin, Manuela M; Leder, Helmut

2013-01-01

Subjective complexity has been found to be related to hedonic measures of preference, pleasantness and beauty, but there is no consensus about the nature of this relationship in the visual and musical domains. Moreover, the affective content of stimuli has been largely neglected so far in the study of complexity but is crucial in many everyday contexts and in aesthetic experiences. We thus propose a cross-domain approach that acknowledges the multidimensional nature of complexity and that uses a wide range of objective complexity measures combined with subjective ratings. In four experiments, we employed pictures of affective environmental scenes, representational paintings, and Romantic solo and chamber music excerpts. Stimuli were pre-selected to vary in emotional content (pleasantness and arousal) and complexity (low versus high number of elements). For each set of stimuli, in a between-subjects design, ratings of familiarity, complexity, pleasantness and arousal were obtained for a presentation time of 25 s from 152 participants. In line with Berlyne's collative-motivation model, statistical analyses controlling for familiarity revealed a positive relationship between subjective complexity and arousal, and the highest correlations were observed for musical stimuli. Evidence for a mediating role of arousal in the complexity-pleasantness relationship was demonstrated in all experiments, but was only significant for females with regard to music. The direction and strength of the linear relationship between complexity and pleasantness depended on the stimulus type and gender. For environmental scenes, the root mean square contrast measures and measures of compressed file size correlated best with subjective complexity, whereas only edge detection based on phase congruency yielded equivalent results for representational paintings. Measures of compressed file size and event density also showed positive correlations with complexity and arousal in music, which is relevant for the discussion on which aspects of complexity are domain-specific and which are domain-general.

What Makes Reading Difficult: The Complexity of Structures.

ERIC Educational Resources Information Center

Schmidt, Eunice L.

The original version of the "Helen Keller Story" and a linguistically more complex version of it were used to test the hypothesis that reading comprehension is affected by the complexity of linguistic structures. Complexity was measured by four readability measures, the mean number of words per T-unit, and the Schmidt-Kittrell Linguistic…

Challenges in researching violence affecting health service delivery in complex security environments.

PubMed

Foghammar, Ludvig; Jang, Suyoun; Kyzy, Gulzhan Asylbek; Weiss, Nerina; Sullivan, Katherine A; Gibson-Fall, Fawzia; Irwin, Rachel

2016-08-01

Complex security environments are characterized by violence (including, but not limited to "armed conflict" in the legal sense), poverty, environmental disasters and poor governance. Violence directly affecting health service delivery in complex security environments includes attacks on individuals (e.g. doctors, nurses, administrators, security guards, ambulance drivers and translators), obstructions (e.g. ambulances being stopped at checkpoints), discrimination (e.g. staff being pressured to treat one patient instead of another), attacks on and misappropriation of health facilities and property (e.g. vandalism, theft and ambulance theft by armed groups), and the criminalization of health workers. This paper examines the challenges associated with researching the context, scope and nature of violence directly affecting health service delivery in these environments. With a focus on data collection, it considers how these challenges affect researchers' ability to analyze the drivers of violence and impact of violence. This paper presents key findings from two research workshops organized in 2014 and 2015 which convened researchers and practitioners in the fields of health and humanitarian aid delivery and policy, and draws upon an analysis of organizational efforts to address violence affecting healthcare delivery and eleven in-depth interviews with representatives of organizations working in complex security environments. Despite the urgency and impact of violence affecting healthcare delivery, there is an overall lack of research that is of health-specific, publically accessible and comparable, as well as a lack of gender-disaggregated data, data on perpetrator motives and an assessment of the 'knock-on' effects of violence. These gaps limit analysis and, by extension, the ability of organizations operating in complex security environments to effectively manage the security of their staff and facilities and to deliver health services. Increased research collaboration among aid organizations, researchers and multilateral organizations, such as the WHO, is needed to address these challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Factors Influencing Adaptation and Performance at Physical Exercise in Complex Congenital Heart Diseases after Surgical Repair

PubMed Central

Bassareo, P. P.; Saba, L.; Solla, P.; Barbanti, C.; Marras, A. R.; Mercuro, G.

2014-01-01

In the last thirty years, steady progress in the diagnostic tools and care of subjects affected by congenital heart diseases (CHD) has resulted in a significant increase in their survival to adulthood, even for those affected by complex CHD. Based on these premises, a number of teenagers and adults affected by corrected (surgically or through interventional techniques) CHD ask to be allowed to undertake sporting activities, both at a recreational and competitive level. The purpose of this review is to examine the mechanisms influencing the adaption at physical exercise of patients suffering from complex CHD. The conclusion is that even if there are some modest risks with exercise, they should be seen in perspective, and the life-long benefits of regular exercise on general health, mood, and well-being should be emphasized. PMID:24822218

Can modular psychological concepts like affect and emotion be assigned to a distinct subset of regional neural circuits?. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

NASA Astrophysics Data System (ADS)

Fehr, Thorsten; Herrmann, Manfred

2015-06-01

The proposed Quartet Theory of Human Emotions by Koelsch and co-workers [11] adumbrates evidence from various scientific sources to integrate and assign the psychological concepts of 'affect' and 'emotion' to four brain circuits or to four neuronal core systems for affect-processing in the brain. The authors differentiate between affect and emotion and assign several facultative, or to say modular, psychological domains and principles of information processing, such as learning and memory, antecedents of affective activity, emotion satiation, cognitive complexity, subjective quality feelings, degree of conscious appraisal, to different affect systems. Furthermore, they relate orbito-frontal brain structures to moral affects as uniquely human, and the hippocampus to attachment-related affects. An additional feature of the theory describes 'emotional effector-systems' for motor-related processes (e.g., emotion-related actions), physiological arousal, attention and memory that are assumed to be cross-linked with the four proposed affect systems. Thus, higher principles of emotional information processing, but also modular affect-related issues, such as moral and attachment related affects, are thought to be handled by these four different physiological sub-systems that are on the other side assumed to be highly interwoven at both physiological and functional levels. The authors also state that the proposed sub-systems have many features in common, such as the selection and modulation of biological processes related to behaviour, perception, attention and memory. The latter aspect challenges an ongoing discussion about the mind-body problem: To which degree do the proposed sub-systems 'sufficiently' cover the processing of complex modular or facultative emotional/affective and/or cognitive phenomena? There are current models and scientific positions that almost completely reject the idea that modular psychological phenomena are handled by a distinct selection of regional brain systems or neural modules, but rather suggest highly complex and cross-linked neural networks individually shaped by livelong learning and experience [e.g., 6,7,10,13]. This holds in particular true for complex emotional phenomena such as aggression or empathy in social interaction [8,13]. It thus remains questionable, whether - beyond primary sensory and motor-processing - a small number of modular sub-systems sufficiently cover the organisation of specific phenomenological and social features of perception and behaviour [7,10].

Melorheostosis: report of two cases affecting the jaw.

PubMed

Parashar, Pallavi; Musella, Anthony; Novak, Timothy; Greer, Robert O

2007-10-01

Melorheostosis is a rare sclerosing bone dysplasia that is characterized by a localized, diffuse thickening of the cortical bone. This condition usually affects the appendicular skeleton and associated soft tissue and rarely affects the craniofacial complex. The etiology of this condition is obscure. Diagnosis of melorheostosis relies on clinical, radiographic, and histological correlation. Only 8 cases of melorheostosis involving the craniofacial complex have been reported. We report 2 new cases of isolated melorheostosis involving the maxilla and mandible, together with differential diagnostic considerations. To our knowledge, involvement of the maxilla only has not been previously reported.

Is the hand to speech what speech is to the hand?

PubMed

Mildner, V

2000-01-01

Interference between the manual and the verbal performance on two types of concurrent verbal-manual tasks was studied on a sample of 48 female right-handers. The more complex verbal task (storytelling) affected both hands significantly, the less complex (essentially phonemic) task affected only the right hand, with insignificant negative influence on the left-hand performance. No significant reciprocal effects of the motor task on verbalization were found.

Mass Spectral Enhanced Detection of Ubls Using SWATH Acquisition: MEDUSA—Simultaneous Quantification of SUMO and Ubiquitin-Derived Isopeptides

NASA Astrophysics Data System (ADS)

Griffiths, John R.; Chicooree, Navin; Connolly, Yvonne; Neffling, Milla; Lane, Catherine S.; Knapman, Thomas; Smith, Duncan L.

2014-05-01

Protein modification by ubiquitination and SUMOylation occur throughout the cell and are responsible for numerous cellular functions such as apoptosis, DNA replication and repair, and gene transcription. Current methods for the identification of such modifications using mass spectrometry predominantly rely upon tryptic isopeptide tag generation followed by database searching with in vitro genetic mutation of SUMO routinely required. We have recently described a novel approach to ubiquitin and SUMO modification detection based upon the diagnostic a' and b' ions released from the isopeptide tags upon collision-induced dissociation of reductively methylated Ubl isopeptides (RUbI) using formaldehyde. Here, we significantly extend those studies by combining data-independent acquisition (DIA) with alternative labeling reagents to improve diagnostic ion coverage and enable relative quantification of modified peptides from both MS and MS/MS signals. Model synthetic ubiquitin and SUMO-derived isopeptides were labeled with mTRAQ reagents (Δ0, Δ4, and Δ8) and subjected to LC-MS/MS with SWATH acquisition. Novel diagnostic ions were generated upon CID, which facilitated the selective detection of these modified peptides. Simultaneous MS-based and MS/MS-based relative quantification was demonstrated for both Ub and SUMO-derived isopeptides across three channels in a background of mTRAQ-labeled Escherichia coli digest.

Glutamic Acid Residues in HIV-1 p6 Regulate Virus Budding and Membrane Association of Gag

PubMed Central

Friedrich, Melanie; Setz, Christian; Hahn, Friedrich; Matthaei, Alina; Fraedrich, Kirsten; Rauch, Pia; Henklein, Petra; Traxdorf, Maximilian; Fossen, Torgils; Schubert, Ulrich

2016-01-01

The HIV-1 Gag p6 protein regulates the final abscission step of nascent virions from the cell membrane by the action of its two late (l-) domains, which recruit Tsg101 and ALIX, components of the ESCRT system. Even though p6 consists of only 52 amino acids, it is encoded by one of the most polymorphic regions of the HIV-1 gag gene and undergoes various posttranslational modifications including sumoylation, ubiquitination, and phosphorylation. In addition, it mediates the incorporation of the HIV-1 accessory protein Vpr into budding virions. Despite its small size, p6 exhibits an unusually high charge density. In this study, we show that mutation of the conserved glutamic acids within p6 increases the membrane association of Pr55 Gag followed by enhanced polyubiquitination and MHC-I antigen presentation of Gag-derived epitopes, possibly due to prolonged exposure to membrane bound E3 ligases. The replication capacity of the total glutamic acid mutant E0A was almost completely impaired, which was accompanied by defective virus release that could not be rescued by ALIX overexpression. Altogether, our data indicate that the glutamic acids within p6 contribute to the late steps of viral replication and may contribute to the interaction of Gag with the plasma membrane. PMID:27120610

Glutamic Acid Residues in HIV-1 p6 Regulate Virus Budding and Membrane Association of Gag.

PubMed

Friedrich, Melanie; Setz, Christian; Hahn, Friedrich; Matthaei, Alina; Fraedrich, Kirsten; Rauch, Pia; Henklein, Petra; Traxdorf, Maximilian; Fossen, Torgils; Schubert, Ulrich

2016-04-25

The HIV-1 Gag p6 protein regulates the final abscission step of nascent virions from the cell membrane by the action of its two late (L-) domains, which recruit Tsg101 and ALIX, components of the ESCRT system. Even though p6 consists of only 52 amino acids, it is encoded by one of the most polymorphic regions of the HIV-1 gag gene and undergoes various posttranslational modifications including sumoylation, ubiquitination, and phosphorylation. In addition, it mediates the incorporation of the HIV-1 accessory protein Vpr into budding virions. Despite its small size, p6 exhibits an unusually high charge density. In this study, we show that mutation of the conserved glutamic acids within p6 increases the membrane association of Pr55 Gag followed by enhanced polyubiquitination and MHC-I antigen presentation of Gag-derived epitopes, possibly due to prolonged exposure to membrane bound E3 ligases. The replication capacity of the total glutamic acid mutant E0A was almost completely impaired, which was accompanied by defective virus release that could not be rescued by ALIX overexpression. Altogether, our data indicate that the glutamic acids within p6 contribute to the late steps of viral replication and may contribute to the interaction of Gag with the plasma membrane.

Distinct Functional Domains of Ubc9 Dictate Cell Survival and Resistance to Genotoxic Stress

PubMed Central

van Waardenburg, Robert C. A. M.; Duda, David M.; Lancaster, Cynthia S.; Schulman, Brenda A.; Bjornsti, Mary-Ann

2006-01-01

Covalent modification with SUMO alters protein function, intracellular localization, or protein-protein interactions. Target recognition is determined, in part, by the SUMO E2 enzyme, Ubc9, while Siz/Pias E3 ligases may facilitate select interactions by acting as substrate adaptors. A yeast conditional Ubc9P123L mutant was viable at 36°C yet exhibited enhanced sensitivity to DNA damage. To define functional domains in Ubc9 that dictate cellular responses to genotoxic stress versus those necessary for cell viability, a 1.75-Å structure of yeast Ubc9 that demonstrated considerable conservation of backbone architecture with human Ubc9 was solved. Nevertheless, differences in side chain geometry/charge guided the design of human/yeast chimeras, where swapping domains implicated in (i) binding residues within substrates that flank canonical SUMOylation sites, (ii) interactions with the RanBP2 E3 ligase, and (iii) binding of the heterodimeric E1 and SUMO had distinct effects on cell growth and resistance to DNA-damaging agents. Our findings establish a functional interaction between N-terminal and substrate-binding domains of Ubc9 and distinguish the activities of E3 ligases Siz1 and Siz2 in regulating cellular responses to genotoxic stress. PMID:16782883

Post-Translational Modification Biology of Glutamate Receptors and Drug Addiction

PubMed Central

Mao, Li-Min; Guo, Ming-Lei; Jin, Dao-Zhong; Fibuch, Eugene E.; Choe, Eun Sang; Wang, John Q.

2011-01-01

Post-translational covalent modifications of glutamate receptors remain a hot topic. Early studies have established that this family of receptors, including almost all ionotropic and metabotropic glutamate receptor subtypes, undergoes active phosphorylation at serine, threonine, or tyrosine residues in their intracellular domains. Recent evidence identifies several glutamate receptor subtypes to be direct substrates for palmitoylation at cysteine residues. Other modifications such as ubiquitination and sumoylation at lysine residues also occur to certain glutamate receptors. These modifications are dynamic and reversible in nature and are regulatable by changing synaptic inputs. The regulated modifications significantly impact the receptor in many ways, including interrelated changes in biochemistry (synthesis, subunit assembling, and protein–protein interactions), subcellular redistribution (trafficking, endocytosis, synaptic delivery, and clustering), and physiology, usually associated with changes in synaptic plasticity. Glutamate receptors are enriched in the striatum and cooperate closely with dopamine to regulate striatal signaling. Emerging evidence shows that modification processes of striatal glutamate receptors are sensitive to addictive drugs, such as psychostimulants (cocaine and amphetamine). Altered modifications are believed to be directly linked to enduring receptor/synaptic plasticity and drug-seeking. This review summarizes several major types of modifications of glutamate receptors and analyzes the role of these modifications in striatal signaling and in the pathogenesis of psychostimulant addiction. PMID:21441996

novPTMenzy: a database for enzymes involved in novel post-translational modifications

PubMed Central

Khater, Shradha; Mohanty, Debasisa

2015-01-01

With the recent discoveries of novel post-translational modifications (PTMs) which play important roles in signaling and biosynthetic pathways, identification of such PTM catalyzing enzymes by genome mining has been an area of major interest. Unlike well-known PTMs like phosphorylation, glycosylation, SUMOylation, no bioinformatics resources are available for enzymes associated with novel and unusual PTMs. Therefore, we have developed the novPTMenzy database which catalogs information on the sequence, structure, active site and genomic neighborhood of experimentally characterized enzymes involved in five novel PTMs, namely AMPylation, Eliminylation, Sulfation, Hydroxylation and Deamidation. Based on a comprehensive analysis of the sequence and structural features of these known PTM catalyzing enzymes, we have created Hidden Markov Model profiles for the identification of similar PTM catalyzing enzymatic domains in genomic sequences. We have also created predictive rules for grouping them into functional subfamilies and deciphering their mechanistic details by structure-based analysis of their active site pockets. These analytical modules have been made available as user friendly search interfaces of novPTMenzy database. It also has a specialized analysis interface for some PTMs like AMPylation and Eliminylation. The novPTMenzy database is a unique resource that can aid in discovery of unusual PTM catalyzing enzymes in newly sequenced genomes. Database URL: http://www.nii.ac.in/novptmenzy.html PMID:25931459

The Sumo-targeted ubiquitin ligase RNF4 regulates the localization and function of the HTLV-1 oncoprotein Tax

PubMed Central

Fryrear, Kimberly A.; Guo, Xin

2012-01-01

The Really Interesting New Gene (RING) Finger Protein 4 (RNF4) represents a class of ubiquitin ligases that target Small Ubiquitin-like Modifier (SUMO)–modified proteins for ubiquitin modification. To date, the regulatory function of RNF4 appears to be ubiquitin-mediated degradation of sumoylated cellular proteins. In the present study, we show that the Human T-cell Leukemia Virus Type 1 (HTLV-1) oncoprotein Tax is a substrate for RNF4 both in vivo and in vitro. We mapped the RNF4-binding site to a region adjacent to the Tax ubiquitin/SUMO modification sites K280/K284. Interestingly, RNF4 modification of Tax protein results in relocalization of the oncoprotein from the nucleus to the cytoplasm. Overexpression of RNF4, but not the RNF4 RING mutant, resulted in cytoplasmic enrichment of Tax. The RNF4-induced nucleus-to-cytoplasm relocalization was associated with increased NF-κB–mediated and decreased cAMP Response Element-Binding (CREB)–mediated Tax activity. Finally, depletion of RNF4 by RNAi prevented the DNA damage–induced nuclear/cytoplasmic translocation of Tax. These results provide important new insight into STUbL-mediated pathways that regulate the subcellular localization and functional dynamics of viral oncogenes. PMID:22106342

The estrogen receptor alpha nuclear localization sequence is critical for fulvestrant-induced degradation of the receptor.

PubMed

Casa, Angelo J; Hochbaum, Daniel; Sreekumar, Sreeja; Oesterreich, Steffi; Lee, Adrian V

2015-11-05

Fulvestrant, a selective estrogen receptor down-regulator (SERD) is a pure competitive antagonist of estrogen receptor alpha (ERα). Fulvestrant binds ERα and reduces the receptor's half-life by increasing protein turnover, however, its mechanism of action is not fully understood. In this study, we show that removal of the ERα nuclear localization sequence (ERΔNLS) resulted in a predominantly cytoplasmic ERα that was degraded in response to 17-β-estradiol (E2) but was resistant to degradation by fulvestrant. ERΔNLS bound the ligands and exhibited receptor interaction similar to ERα, indicating that the lack of degradation was not due to disruption of these processes. Forcing ERΔNLS into the nucleus with a heterologous SV40-NLS did not restore degradation, suggesting that the NLS domain itself, and not merely receptor localization, is critical for fulvestrant-induced ERα degradation. Indeed, cloning of the endogenous ERα NLS onto the N-terminus of ERΔNLS significantly restored both its nuclear localization and turnover in response to fulvestrant. Moreover, mutation of the sumoylation targets K266 and K268 within the NLS impaired fulvestrant-induced ERα degradation. In conclusion, our study provides evidence for the unique role of the ERα NLS in fulvestrant-induced degradation of the receptor. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Post-translational Regulation of Neuronal Nitric Oxide Synthase: Implications for sympatho-excitatory states

PubMed Central

Sharma, Neeru M; Patel, Kaushik P

2017-01-01

Introduction Nitric oxide (NO) synthesized via neuronal nitric oxide synthase (nNOS) plays a significant role in regulation/modulation of autonomic control of circulation. Various pathological states are associated with diminished nNOS expression and blunted autonomic effects of NO in the central nervous system (CNS) including heart failure, hypertension, diabetes mellitus, chronic renal failure etc. Therefore, elucidation of the molecular mechanism/s involved in dysregulation of nNOS is essential to understand the pathogenesis of increased sympathoexcitation in these diseased states. Areas Covered nNOS is a highly regulated enzyme, being regulated at transcriptional and posttranslational levels via protein-protein interactions and modifications viz. phosphorylation, ubiquitination, and sumoylation. The enzyme activity of nNOS also depends on the optimal concentration of substrate, cofactors and association with regulatory proteins. This review focuses on the posttranslational regulation of nNOS in the context of normal and diseased states within the CNS. Expert Opinion Gaining insight into the mechanism/s involved in the regulation of nNOS would provide novel strategies for manipulating nNOS directed therapeutic modalities in the future, including catalytically active dimer stabilization and protein-protein interactions with intracellular protein effectors. Ultimately, this is expected to provide tools to improve autonomic dysregulation in various diseases such as heart failure, hypertension, and diabetes. PMID:27885874

Regulating with imagery and the complexity of basic emotions. Comment on "The quartet theory of human emotions: An integrative and neurofunctional model" by S. Koelsch et al.

NASA Astrophysics Data System (ADS)

Meyer, Marcel; Kuchinke, Lars

2015-06-01

Literature, music and the arts have long attested to the complexity of human emotions. Hitherto, psychological and biological theories of emotions have largely neglected this rich heritage. In their review Koelsch and colleagues [1] have embarked upon the pioneering endeavour of integrating the diverse perspectives in emotion research. Noting that the focus of prior neurobiological theories relies mainly on animal studies, the authors sought to complement this body of research with a model of complex ("moral") emotions in humans (henceforth: complex emotions). According to this novel framework, there are four main interacting affective centres in the brain. Each centre is associated with a dominant affective function, such as ascending activation (brainstem), pain/pleasure (diencephalon), attachment-related affects (hippocampus) or moral emotions and unconscious cognitive appraisal (orbitofrontal cortex). Furthermore, language is ascribed a key role in (a) the communication of subjective feeling (reconfiguration) and (b) in the conscious regulation of emotions (by means of logic and rational thought).

Does human migration affect international trade? A complex-network perspective.

PubMed

Fagiolo, Giorgio; Mastrorillo, Marina

2014-01-01

This paper explores the relationships between international human migration and merchandise trade, using a complex-network approach. We firstly compare the topological structure of worldwide networks of human migration and bilateral trade over the period 1960-2000. Next, we ask whether the position of any pair of countries in the migration network affects their bilateral trade flows. We show that: (i) both weighted and binary versions of the networks of international migration and trade are strongly correlated; (ii) such correlations can be mostly explained by country economic/demographic size and geographical distance; and (iii) pairs of countries that are more central in the international-migration network trade more. Our findings suggest that bilateral trade between any two countries is not only affected by the presence of migrants from either countries but also by their relative embeddedness in the complex web of corridors making up the network of international human migration.

Unraveling dynamics of human physical activity patterns in chronic pain conditions

NASA Astrophysics Data System (ADS)

Paraschiv-Ionescu, Anisoara; Buchser, Eric; Aminian, Kamiar

2013-06-01

Chronic pain is a complex disabling experience that negatively affects the cognitive, affective and physical functions as well as behavior. Although the interaction between chronic pain and physical functioning is a well-accepted paradigm in clinical research, the understanding of how pain affects individuals' daily life behavior remains a challenging task. Here we develop a methodological framework allowing to objectively document disruptive pain related interferences on real-life physical activity. The results reveal that meaningful information is contained in the temporal dynamics of activity patterns and an analytical model based on the theory of bivariate point processes can be used to describe physical activity behavior. The model parameters capture the dynamic interdependence between periods and events and determine a `signature' of activity pattern. The study is likely to contribute to the clinical understanding of complex pain/disease-related behaviors and establish a unified mathematical framework to quantify the complex dynamics of various human activities.

Advancing complex explanatory conceptualizations of daily negative and positive affect: trigger and maintenance coping action patterns.

PubMed

Dunkley, David M; Ma, Denise; Lee, Ihno A; Preacher, Kristopher J; Zuroff, David C

2014-01-01

The present study addressed a fundamental gap between research and clinical work by advancing complex explanatory conceptualizations of coping action patterns that trigger and maintain daily negative affect and (low) positive affect. One hundred ninety-six community adults completed measures of perfectionism, and then 6 months later completed questionnaires at the end of the day for 14 consecutive days to provide simultaneous assessments of appraisals, coping, and affect across different stressful situations in everyday life. Multilevel structural equation modeling (MSEM) supported complex explanatory conceptualizations that demonstrated (a) disengagement trigger patterns consisting of several distinct appraisals (e.g., event stress) and coping strategies (e.g., avoidant coping) that commonly operate together across many different stressors when the typical individual experiences daily increases in negative affect and drops in positive affect; and (b) disengagement maintenance patterns composed of different appraisal and coping maintenance factors that, in combination, can explain why individuals with higher levels of self-critical perfectionism have persistent daily negative affect and low positive mood 6 months later. In parallel, engagement patterns (triggers and maintenance) composed of distinct appraisals (e.g., perceived social support) and coping strategies (e.g., problem-focused coping) were linked to compensatory experiences of daily positive affect. These findings demonstrate the promise of using daily diary methodologies and MSEM to promote a shared understanding between therapists and clients of trigger and maintenance coping action patterns that explain what precipitates and perpetuates clients' difficulties, which, in turn, can help achieve the 2 overarching therapy goals of reducing clients' distress and bolstering resilience. (c) 2014 APA, all rights reserved.

Spatially defined modulation of skin temperature and hand ownership of both hands in patients with unilateral complex regional pain syndrome.

PubMed

Moseley, G Lorimer; Gallace, Alberto; Iannetti, Gian Domenico

2012-12-01

Numerous clinical conditions, including complex regional pain syndrome, are characterized by autonomic dysfunctions (e.g. altered thermoregulation, sometimes confined to a single limb), and disrupted cortical representation of the body and the surrounding space. The presence, in patients with complex regional pain syndrome, of a disruption in spatial perception, bodily ownership and thermoregulation led us to hypothesize that impaired spatial perception might result in a spatial-dependent modulation of thermoregulation and bodily ownership over the affected limb. In five experiments involving a total of 23 patients with complex regional pain syndrome of one arm and 10 healthy control subjects, we measured skin temperature of the hand with infrared thermal imaging, before and after experimental periods of either 9 or 10 min each, during which the hand was held on one or the other side of the body midline. Tactile processing was assessed by temporal order judgements of pairs of vibrotactile stimuli, delivered one to each hand. Pain and sense of ownership over the hand were assessed by self-report scales. Across experiments, when kept on its usual side of the body midline, the affected hand was 0.5 ± 0.3°C cooler than the healthy hand (P < 0.02 for all, a common finding in cold-type complex regional pain syndrome), and tactile stimuli delivered to the healthy hand were prioritized over those delivered to the affected hand. Simply crossing both hands over the midline resulted in (i) warming of the affected hand (the affected hand became 0.4 ± 0.3°C warmer than when it was in the uncrossed position; P = 0.01); (ii) cooling of the healthy hand (by 0.3 ± 0.3°C; P = 0.02); and (iii) reversal of the prioritization of tactile processing. When only the affected hand was crossed over the midline, it became warmer (by 0.5 ± 0.3°C; P = 0.01). When only the healthy hand was crossed over the midline, it became cooler (by 0.3 ± 0.3°C; P = 0.01). The temperature change of either hand was positively related to its distance from the body midline (pooled data: r = 0.76, P < 0.001). Crossing the affected hand over the body midline had small but significant effects on both spontaneous pain (which was reduced) and the sense of ownership over the hand (which was increased) (P < 0.04 for both). We conclude that impaired spatial perception modulated temperature of the limbs, tactile processing, spontaneous pain and the sense of ownership over the hands. These results show that complex regional pain syndrome involves more complex neurological dysfunction than has previously been considered.

Biased and unbiased perceptual decision-making on vocal emotions.

PubMed

Dricu, Mihai; Ceravolo, Leonardo; Grandjean, Didier; Frühholz, Sascha

2017-11-24

Perceptual decision-making on emotions involves gathering sensory information about the affective state of another person and forming a decision on the likelihood of a particular state. These perceptual decisions can be of varying complexity as determined by different contexts. We used functional magnetic resonance imaging and a region of interest approach to investigate the brain activation and functional connectivity behind two forms of perceptual decision-making. More complex unbiased decisions on affective voices recruited an extended bilateral network consisting of the posterior inferior frontal cortex, the orbitofrontal cortex, the amygdala, and voice-sensitive areas in the auditory cortex. Less complex biased decisions on affective voices distinctly recruited the right mid inferior frontal cortex, pointing to a functional distinction in this region following decisional requirements. Furthermore, task-induced neural connectivity revealed stronger connections between these frontal, auditory, and limbic regions during unbiased relative to biased decision-making on affective voices. Together, the data shows that different types of perceptual decision-making on auditory emotions have distinct patterns of activations and functional coupling that follow the decisional strategies and cognitive mechanisms involved during these perceptual decisions.

Operational Shock Complexity Theory

DTIC Science & Technology

2005-05-26

Theory : Recommendations For The National Strategy To Defeat Terrorism.” Student Issue Paper, Center for Strategic Leadership , US Army War College, July...Lens of Complexity Theory : Recommendations For The National Strategy To Defeat Terrorism.” (Student Issue Paper, Center for Strategic Leadership , US... Leadership Complexity theory affects the training of leaders. With the enemy system able to develop its complexity either through interaction with US

A Different Trolley Problem: The Limits of Environmental Justice and the Promise of Complex Moral Assessments for Transportation Infrastructure.

PubMed

Epting, Shane

2016-12-01

Transportation infrastructure tremendously affects the quality of life for urban residents, influences public and mental health, and shapes social relations. Historically, the topic is rich with social and political controversy and the resultant transit systems in the United States cause problems for minority residents and issues for the public. Environmental justice frameworks provide a means to identify and address harms that affect marginalized groups, but environmental justice has limits that cannot account for the mainstream population. To account for this condition, I employ a complex moral assessment measure that provides a way to talk about harms that affect the public.

Affective Learning: Environmental Ethics and Human Ecology

ERIC Educational Resources Information Center

Gough, Noel P.

1977-01-01

This discussion of home economics as a discipline which should focus on its affective foundations, covers the following areas: Affective context of home economics education, the adequacy of the home economics value complex for coping with environmental problems, and toward an acceptable environmental ethic. (SH)

Queerying the Affective Politics of Doctoral Education: Toward Complex Visions of Agency and Affect

ERIC Educational Resources Information Center

Burford, James

2015-01-01

Higher education (HE) researchers, like their colleagues across the humanities and social sciences, are increasingly tuning in to the political possibilities offered by working with emotion and affect. Reading across this work, it would seem that certain practices, and their associated affects, have achieved an aura of legitimacy, and political…

Making Sense of the Complex Entanglement between Emotion and Pedagogy: Contributions of the "Affective Turn"

ERIC Educational Resources Information Center

Zembylas, Michalinos

2016-01-01

The purpose of this paper is to highlight three recent contributions of the affective turn: moving beyond the emotion/reason dichotomy; highlighting the politics of emotion and affect; and, strengthening the intersections of the psychic and the social. While these contributions are not necessarily paradigmatic of scholarship in the affective turn,…

Fractal dimension assessment of brain white matter structural complexity post stroke in relation to upper-extremity motor function

PubMed Central

Zhang, Luduan; Butler, Andrew J.; Sun, Chang-Kai; Sahgal, Vinod; Wittenberg, George F.; Yue, Guang H.

2008-01-01

Little is known about the association between brain white matter (WM) structure and motor function in humans. This study investigated complexity of brain WM interior shape as determined by magnetic resonance imaging (MRI) and its relationship with upper-extremity (UE) motor function in patients post stroke. We hypothesized that (1) the WM complexity would decrease following stroke, and (2) higher WM complexity in non-affected cortical areas would be related to greater UE motor function. Thirty-eight stroke patients (16 with left-hemisphere lesions) underwent MRI anatomical brain scans. Fractal dimension (FD), a quantitative shape metric, was applied onto skeletonized brain WM images to evaluate WM internal structural complexity. Wolf Motor Function Test (WMFT) and Fugl-Meyer Motor Assessment (FM) scores were measured to assess motor function of the affected limb. The WM complexity was lower in the stroke-affected hemisphere. The FD was associated with better motor function in two subgroups: with left-subcortical lesions, FD values of the lesion-free areas of the left hemisphere were associated with better FM scores; with right-cortical lesions, FD values of lesion-free regions were robustly associated with better WMFT scores. These findings suggest that greater residual WM complexity is associated with less impaired UE motor function, which is more robust in patients with right-hemisphere lesions. No correlations were found between lesion volume and WMFT or FM scores. This study addressed WM complexity in stroke patients and its relationship with UE motor function. Measurement of brain WM reorganization may be a sensitive correlate of UE function in people recovering from stroke. PMID:18590710

Cross-modal links among vision, audition, and touch in complex environments.

PubMed

Ferris, Thomas K; Sarter, Nadine B

2008-02-01

This study sought to determine whether performance effects of cross-modal spatial links that were observed in earlier laboratory studies scale to more complex environments and need to be considered in multimodal interface design. It also revisits the unresolved issue of cross-modal cuing asymmetries. Previous laboratory studies employing simple cues, tasks, and/or targets have demonstrated that the efficiency of processing visual, auditory, and tactile stimuli is affected by the modality, lateralization, and timing of surrounding cues. Very few studies have investigated these cross-modal constraints in the context of more complex environments to determine whether they scale and how complexity affects the nature of cross-modal cuing asymmetries. Amicroworld simulation of battlefield operations with a complex task set and meaningful visual, auditory, and tactile stimuli was used to investigate cuing effects for all cross-modal pairings. Significant asymmetric performance effects of cross-modal spatial links were observed. Auditory cues shortened response latencies for collocated visual targets but visual cues did not do the same for collocated auditory targets. Responses to contralateral (rather than ipsilateral) targets were faster for tactually cued auditory targets and each visual-tactile cue-target combination, suggesting an inhibition-of-return effect. The spatial relationships between multimodal cues and targets significantly affect target response times in complex environments. The performance effects of cross-modal links and the observed cross-modal cuing asymmetries need to be examined in more detail and considered in future interface design. The findings from this study have implications for the design of multimodal and adaptive interfaces and for supporting attention management in complex, data-rich domains.

Association between increased EEG signal complexity and cannabis dependence.

PubMed

Laprevote, Vincent; Bon, Laura; Krieg, Julien; Schwitzer, Thomas; Bourion-Bedes, Stéphanie; Maillard, Louis; Schwan, Raymund

2017-12-01

Both acute and regular cannabis use affects the functioning of the brain. While several studies have demonstrated that regular cannabis use can impair the capacity to synchronize neural assemblies during specific tasks, less is known about spontaneous brain activity. This can be explored by measuring EEG complexity, which reflects the spontaneous variability of human brain activity. A recent study has shown that acute cannabis use can affect that complexity. Since the characteristics of cannabis use can affect the impact on brain functioning, this study sets out to measure EEG complexity in regular cannabis users with or without dependence, in comparison with healthy controls. We recruited 26 healthy controls, 25 cannabis users without cannabis dependence and 14 cannabis users with cannabis dependence, based on DSM IV TR criteria. The EEG signal was extracted from at least 250 epochs of the 500ms pre-stimulation phase during a visual evoked potential paradigm. Brain complexity was estimated using Lempel-Ziv Complexity (LZC), which was compared across groups by non-parametric Kruskall-Wallis ANOVA. The analysis revealed a significant difference between the groups, with higher LZC in participants with cannabis dependence than in non-dependent cannabis users. There was no specific localization of this effect across electrodes. We showed that cannabis dependence is associated to an increased spontaneous brain complexity in regular users. This result is in line with previous results in acute cannabis users. It may reflect increased randomness of neural activity in cannabis dependence. Future studies should explore whether this effect is permanent or diminishes with cannabis cessation. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

Construction of "Toxin Complex" in a Mutant Serotype C Strain of Clostridium botulinum Harboring a Defective Neurotoxin Gene.

PubMed

Suzuki, Tomonori; Nagano, Thomas; Niwa, Koichi; Uchino, Masataka; Tomizawa, Motohiro; Sagane, Yoshimasa; Watanabe, Toshihiro

2017-01-01

A non-toxigenic mutant of the toxigenic serotype C Clostridium botulinum strain Stockholm (C-St), C-N71, does not produce the botulinum neurotoxin (BoNT). However, the original strain C-St produces botulinum toxin complex, in which BoNT is associated with non-toxic non-hemagglutinin (NTNHA) and three hemagglutinin proteins (HA-70, HA-33, and HA-17). Therefore, in this study, we aimed to elucidate the effects of bont gene knockout on the formation of the "toxin complex." Nucleotide sequence analysis revealed that a premature stop codon was introduced in the bont gene, whereas other genes were not affected by this mutation. Moreover, we successfully purified the "toxin complex" produced by C-N71. The "toxin complex" was identified as a mixture of NTNHA/HA-70/HA-17/HA-33 complexes with intact NTNHA or C-terminally truncated NTNHA, without BoNT. These results indicated that knockout of the bont gene does not affect the formation of the "toxin complex." Since the botulinum toxin complex has been shown to play an important role in oral toxin transport in the human and animal body, a non-neurotoxic "toxin complex" of C-N71 may be valuable for the development of an oral drug delivery system.

Fate of Pharmaceuticals and Personal Care Products (PPCPs) in Saturated Soil Under Various Redox Conditions

NASA Astrophysics Data System (ADS)

Dror, I.; Menahem, A.; Berkowitz, B.

2014-12-01

The growing use of PPCPs results in their increasing release to the aquatic environment. Consequently, understanding the fate of PPCPs under environmentally relevant conditions that account for dynamic flow and varying redox states is critical. In this study, the transport of two organometallic PPCPs, Gd-DTPA and Roxarsone (As complex) and their metal salts (Gd(NO3)3, AsNaO2), is investigated. The former is used widely as a contrasting agent for MRI, while the latter is applied extensively as a food additive in the broiler poultry industry. Both of these compounds are excreted from the body, almost unchanged chemically. Gadolinium complexes are not fully eliminated in wastewater treatment and can reach groundwater via irrigation with treated wastewater; Roxarsone can enter groundwater via leaching from manure used as fertilizer. Studies have shown that the transport of PPCPs in groundwater is affected by environmental conditions such as redox states, pH, and soil type. For this study, column experiments using sand or Mediterranean red sandy clay soil were performed under several redox conditions: aerobic, nitrate-reducing, iron-reducing, sulfate-reducing, methanogenic, and very strongly chemical reducing. Batch experiments to determine adsorption isotherms were also performed for the complexes and metal salts. We found that Gd-DTPA transport was affected by the soil type and was not affected by the redox conditions. In contrast, Roxarsone transport was affected mainly by the different redox conditions, showing delayed breakthrough curves as the conditions became more biologically reduced (strong chemical reducing conditions did not affect the transport). We also observed that the metal salts show essentially no transport while the organic complexes display much faster breakthrough. The results suggest that transport of these PPCPs through soil and groundwater is determined by the redox conditions, as well as by soil type and the form of the applied metal (as salt or organic complex).

Effecting Affect: Developing a Positive Attitude to Primary Mathematics Learning

ERIC Educational Resources Information Center

Sparrow, Len; Hurst, Chris

2010-01-01

Most adults' attitudes to mathematics come from their experiences of mathematics in school when they were children. Children's mathematical worlds are complex places containing both cognitive and affective elements. One cannot ignore the affective domain if one wishes to understand children's mathematical learning. Teacher education students…

Using Focus Groups to Modify the Workplace Affective Commitment Multidimensional Questionnaire (WACMQ) for use in Health Care.

PubMed

Perreira, Tyrone; Berta, Whitney

2016-01-01

BACKGROUND: The Workplace Affective Commitment Multidimensional Questionnaire (W ACMQ) measures affective commitment towards eight work-related targets. While this questionnaire was developed in the business sector, we believe that the multi-target conceptualization of affective commitment has applicability to complex health care contexts where providers of care, in the production and delivery of care, likely develop commitment toward a multiplicity of targets. Affective commitment is a strong predictor of extra-role workplace behavior; indispensable behaviors which enable health systems to function. OBJECTIVE: The aim of this psychometric exercise is to content validate the WACMQ questions for use in health care. METHODS: Two focus groups were conducted, consisting of nurses working in acute care and emergency hospitals in Ontario. Linguistic validation and cognitive debriefing were used. RESULTS: A total of 14 modifications to the wording of items on the original WACMQ questionnaire were made. CONCLUSIONS: This modified version of the WACMQ reflects the need for researchers in health care settings to acknowledge the complex context of health care and the attendant complexities of worker attitudes. Health care workers can experience affective commitment toward leadership (clinical or administrative), co-workers (nurses or interprofessional), patients, their profession, organization, work or tasks. Further, in some health care settings, features like union membership may have important implications when examining affective commitment or behaviors. Psychometric properties of the modified WACMQ will be established in an upcoming study that will examine the relationships between extra-role behaviors, commitment, perceived organizational support and justice within acute care and emergency departments of hospitals operating in Ontario.

9 CFR 381.82 - Diseases of the leukosis complex.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 2 2011-01-01 2011-01-01 false Diseases of the leukosis complex. 381.82 Section 381.82 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Carcasses and Parts § 381.82 Diseases of the leukosis complex. Carcasses of poultry affected with any one or...

9 CFR 381.82 - Diseases of the leukosis complex.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Diseases of the leukosis complex. 381.82 Section 381.82 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Carcasses and Parts § 381.82 Diseases of the leukosis complex. Carcasses of poultry affected with any one or...

9 CFR 381.82 - Diseases of the leukosis complex.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 2 2012-01-01 2012-01-01 false Diseases of the leukosis complex. 381.82 Section 381.82 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Carcasses and Parts § 381.82 Diseases of the leukosis complex. Carcasses of poultry affected with any one or...

9 CFR 381.82 - Diseases of the leukosis complex.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 2 2013-01-01 2013-01-01 false Diseases of the leukosis complex. 381.82 Section 381.82 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Carcasses and Parts § 381.82 Diseases of the leukosis complex. Carcasses of poultry affected with any one or...

9 CFR 381.82 - Diseases of the leukosis complex.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 2 2014-01-01 2014-01-01 false Diseases of the leukosis complex. 381.82 Section 381.82 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF... Carcasses and Parts § 381.82 Diseases of the leukosis complex. Carcasses of poultry affected with any one or...

The Ins and Outs of Breath Holding: Simple Demonstrations of Complex Respiratory Physiology

ERIC Educational Resources Information Center

Skow, Rachel J.; Day, Trevor A.; Fuller, Jonathan E.; Bruce, Christina D.; Steinback, Craig D.

2015-01-01

The physiology of breath holding is complex, and voluntary breath-hold duration is affected by many factors, including practice, psychology, respiratory chemoreflexes, and lung stretch. In this activity, we outline a number of simple laboratory activities or classroom demonstrations that illustrate the complexity of the integrative physiology…

Stuttering Frequency in Relation to Lexical Diversity, Syntactic Complexity, and Utterance Length

ERIC Educational Resources Information Center

Wagovich, Stacy A.; Hall, Nancy E.

2018-01-01

Children's frequency of stuttering can be affected by utterance length, syntactic complexity, and lexical content of language. Using a unique small-scale within-subjects design, this study explored whether language samples that contain more stuttering have (a) longer, (b) syntactically more complex, and (c) lexically more diverse utterances than…

Ephemeral collision complexes mediate chemically termolecular transformations that affect system chemistry [Ephemeral collision complexes induce chemically termolecular transformations that affect global chemistry

DOE PAGES

Burke, Michael P.; Klippenstein, Stephen J.

2017-08-14

Termolecular association reactions involve ephemeral collision complexes—formed from the collision of two molecules—that collide with a third and chemically inert ‘bath gas’ molecule that simply transfers energy to/from the complex. These collision complexes are generally not thought to react chemically on collision with a third molecule in the gas-phase systems of combustion and planetary atmospheres. Such ‘chemically termolecular’ reactions, in which all three molecules are involved in bond making and/or breaking, were hypothesized long ago in studies establishing radical chain branching mechanisms, but were later concluded to be unimportant. Here, with data from ab initio master equation and kinetic-transport simulations,more » we reveal that reactions of H+O 2 collision complexes with other radicals constitute major kinetic pathways under common combustion situations. These reactions are also found to influence flame propagation speeds, a common measure of global reactivity. As a result, analogous chemically termolecular reactions mediated by ephemeral collision complexes are probably of significance in various combustion and planetary environments.« less

RNA editing of microRNA prevents RNA-induced silencing complex recognition of target mRNA

PubMed Central

Cui, Yalei; Huang, Tianzhi; Zhang, Xiaobo

2015-01-01

MicroRNAs (miRNAs) integrate with Argonaut (Ago) to create the RNA-induced silencing complex, and regulate gene expression by silencing target mRNAs. RNA editing of miRNA may affect miRNA processing, assembly of the Ago complex and target mRNA binding. However, the function of edited miRNA, assembled within the Ago complex, has not been extensively investigated. In this study, sequence analysis of the Ago complex of Marsupenaeus japonicus shrimp infected with white spot syndrome virus (WSSV) revealed that host ADAR (adenosine deaminase acting on RNA) catalysed A-to-I RNA editing of a viral miRNA (WSSV-miR-N12) at the +16 site. This editing of the non-seed sequence did not affect association of the edited miRNA with the Ago protein, but inhibited interaction between the miRNA and its target gene (wsv399). The WSSV early gene wsv399 inhibited WSSV infection. As a result, the RNA editing of miRNA caused virus latency. Our results highlight a novel example of miRNA editing in the miRNA-induced silencing complex. PMID:26674414

Ephemeral collision complexes mediate chemically termolecular transformations that affect system chemistry [Ephemeral collision complexes induce chemically termolecular transformations that affect global chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burke, Michael P.; Klippenstein, Stephen J.

Termolecular association reactions involve ephemeral collision complexes—formed from the collision of two molecules—that collide with a third and chemically inert ‘bath gas’ molecule that simply transfers energy to/from the complex. These collision complexes are generally not thought to react chemically on collision with a third molecule in the gas-phase systems of combustion and planetary atmospheres. Such ‘chemically termolecular’ reactions, in which all three molecules are involved in bond making and/or breaking, were hypothesized long ago in studies establishing radical chain branching mechanisms, but were later concluded to be unimportant. Here, with data from ab initio master equation and kinetic-transport simulations,more » we reveal that reactions of H+O 2 collision complexes with other radicals constitute major kinetic pathways under common combustion situations. These reactions are also found to influence flame propagation speeds, a common measure of global reactivity. As a result, analogous chemically termolecular reactions mediated by ephemeral collision complexes are probably of significance in various combustion and planetary environments.« less

Thermo-Responsive Complexes of c-Myc Antisense Oligonucleotide with Block Copolymer of Poly(OEGMA) and Quaternized Poly(4-Vinylpyridine).

PubMed

Topuzogullari, Murat; Elalmis, Yeliz Basaran; Isoglu, Sevil Dincer

2017-04-01

Solution behavior of thermo-responsive polymers and their complexes with biological macromolecules may be affected by environmental conditions, such as the concentration of macromolecular components, pH, ion concentration, etc. Therefore, a thermo-responsive polymer and its complexes should be characterized in detail to observe their responses against possible environments under physiological conditions before biological applications. To briefly indicate this important issue, thermo-responsive block copolymer of quaternized poly(4-vinylpyridine) and poly(oligoethyleneglycol methyl ether methacrylate) as a potential nonviral vector has been synthesized. Polyelectrolyte complexes of this copolymer with the antisense oligonucleotide of c-Myc oncogene are also thermo-responsive but, have lower LCST (lower critical solution temperature) values compared to individual copolymer. LCST values of complexes decrease with molar ratio of macromolecular components and presence of salt. Dilution of solutions also affects solution behavior of complexes and causes a significant decrease in size and an increase in LCST, which indicates possible effects of severe dilutions in the blood stream. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Effect of environmental factors on the complexation of iron and humic acid.

PubMed

Fang, Kai; Yuan, Dongxing; Zhang, Lei; Feng, Lifeng; Chen, Yaojin; Wang, Yuzhou

2015-01-01

A method of size exclusion chromatography coupled with ultraviolet spectrophotometry and off-line graphite furnace atomic absorption spectrometry was developed to assess the complexation properties of iron (Fe) and humic acid (HA) in a water environment. The factors affecting the complexation of Fe and HA, such as ionic strength, pH, temperature and UV radiation, were investigated. The Fe-HA complex residence time was also studied. Experimental results showed that pH could influence the deprotonation of HA and hydrolysis of Fe, and thus affected the complexation of Fe and HA. The complexation was greatly disrupted by the presence of NaCl. Temperature had some influence on the complexation. The yield of Fe-HA complexes showed a small decrease at high levels of UV radiation, but the effect of UV radiation on Fe-HA complex formation at natural levels could be neglected. It took about 10 hr for the complexation to reach equilibrium, and the Fe-HA complex residence time was about 20 hr. Complexation of Fe and HA reached a maximum level under the conditions of pH 6, very low ionic strength, in the dark and at a water temperature of about 25°C, for 10 hr. It was suggested that the Fe-HA complex could form mainly in freshwater bodies and reach high levels in the warm season with mild sunlight radiation. With changing environmental parameters, such as at lower temperature in winter or higher pH and ionic strength in an estuary, the concentration of the Fe-HA complex would decrease. Copyright © 2014. Published by Elsevier B.V.

Solubility enhancement of seven metal contaminants using carboxymethyl-β-cyclodextrin (CMCD)

NASA Astrophysics Data System (ADS)

Skold, Magnus E.; Thyne, Geoffrey D.; Drexler, John W.; McCray, John E.

2009-07-01

Carboxymethyl-β-cyclodextrin (CMCD) has been suggested as a complexing agent for remediation of sites co-contaminated with metals and organic pollutants. As part of an attempt to construct a geochemical complexation model for metal-CMCD interactions, conditional formation constants for the complexes between CMCD and 7 metal ions (Ba, Ca, Cd, Ni, Pb, Sr, and Zn) are estimated from experimental data. Stable metal concentrations were reached after approximately 1 day and estimated logarithmic conditional formation constants range from - 3.2 to - 5.1 with confidence intervals within ± 0.08 log units. Experiments performed at 10 °C and 25 °C show that temperature affects the solubility of the metal salts but the strength of CMCD-metal complexes are not affected by this temperature variation. The conditional stability constants and complexation model presented in this work can be used to screen CMCD as a potential remediation agent for clean-up of contaminated soil and groundwater.

Redox Conditions Affect Ultrafast Exciton Transport in Photosynthetic Pigment-Protein Complexes.

PubMed

Allodi, Marco A; Otto, John P; Sohail, Sara H; Saer, Rafael G; Wood, Ryan E; Rolczynski, Brian S; Massey, Sara C; Ting, Po-Chieh; Blankenship, Robert E; Engel, Gregory S

2018-01-04

Pigment-protein complexes in photosynthetic antennae can suffer oxidative damage from reactive oxygen species generated during solar light harvesting. How the redox environment of a pigment-protein complex affects energy transport on the ultrafast light-harvesting time scale remains poorly understood. Using two-dimensional electronic spectroscopy, we observe differences in femtosecond energy-transfer processes in the Fenna-Matthews-Olson (FMO) antenna complex under different redox conditions. We attribute these differences in the ultrafast dynamics to changes to the system-bath coupling around specific chromophores, and we identify a highly conserved tyrosine/tryptophan chain near the chromophores showing the largest changes. We discuss how the mechanism of tyrosine/tryptophan chain oxidation may contribute to these differences in ultrafast dynamics that can moderate energy transfer to downstream complexes where reactive oxygen species are formed. These results highlight the importance of redox conditions on the ultrafast transport of energy in photosynthesis. Tailoring the redox environment may enable energy transport engineering in synthetic light-harvesting systems.

Complex Regional Pain Syndrome

MedlinePlus

Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

Habitat complexity influences fine scale hydrological processes and the incidence of stormwater runoff in managed urban ecosystems.

PubMed

Ossola, Alessandro; Hahs, Amy Kristin; Livesley, Stephen John

2015-08-15

Urban ecosystems have traditionally been considered to be pervious features of our cities. Their hydrological properties have largely been investigated at the landscape scale and in comparison with other urban land use types. However, hydrological properties can vary at smaller scales depending upon changes in soil, surface litter and vegetation components. Management practices can directly and indirectly affect each of these components and the overall habitat complexity, ultimately affecting hydrological processes. This study aims to investigate the influence that habitat components and habitat complexity have upon key hydrological processes and the implications for urban habitat management. Using a network of urban parks and remnant nature reserves in Melbourne, Australia, replicate plots representing three types of habitat complexity were established: low-complexity parks, high-complexity parks, and high-complexity remnants. Saturated soil hydraulic conductivity in low-complexity parks was an order of magnitude lower than that measured in the more complex habitat types, due to fewer soil macropores. Conversely, soil water holding capacity in low-complexity parks was significantly higher compared to the two more complex habitat types. Low-complexity parks would generate runoff during modest precipitation events, whereas high-complexity parks and remnants would be able to absorb the vast majority of rainfall events without generating runoff. Litter layers on the soil surface would absorb most of precipitation events in high-complexity parks and high-complexity remnants. To minimize the incidence of stormwater runoff from urban ecosystems, land managers could incrementally increase the complexity of habitat patches, by increasing canopy density and volume, preserving surface litter and maintaining soil macropore structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Socio-affective touch expression database

PubMed Central

Op de Beeck, Hans

2018-01-01

Socio-affective touch communication conveys a vast amount of information about emotions and intentions in social contexts. In spite of the complexity of the socio-affective touch expressions we use daily, previous studies addressed only a few aspects of social touch mainly focusing on hedonics, such as stroking, leaving a wide range of social touch behaviour unexplored. To overcome this limit, we present the Socio-Affective Touch Expression Database (SATED), which includes a large range of dynamic interpersonal socio-affective touch events varying in valence and arousal. The original database contained 26 different social touch expressions each performed by three actor pairs. To validate each touch expression, we conducted two behavioural experiments investigating perceived naturalness and affective values. Based on the rated naturalness and valence, 13 socio-affective touch expressions along with 12 corresponding non-social touch events were selected as a complete set, achieving 75 video clips in total. Moreover, we quantified motion energy for each touch expression to investigate its intrinsic correlations with perceived affective values and its similarity among actor- and action-pairs. As a result, the touch expression database is not only systematically defined and well-controlled, but also spontaneous and natural, while eliciting clear affective responses. This database will allow a fine-grained investigation of complex interpersonal socio-affective touch in the realm of social psychology and neuroscience along with potential application areas in affective computing and neighbouring fields. PMID:29364988

Vector-virus interactions and transmission dynamics of West Nile virus.

PubMed

Ciota, Alexander T; Kramer, Laura D

2013-12-09

West Nile virus (WNV; Flavivirus; Flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. Mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. The concept of vectorial capacity integrates these factors to address interactions of the virus with the arthropod host, leading to a clearer understanding of their complex interrelationships, how they affect transmission of vector-borne disease, and how they impact human health. Vertebrate factors including host competence, population dynamics, and immune status also affect transmission dynamics. The complexity of these interactions are further exacerbated by the fact that not only can divergent hosts differentially alter the virus, but the virus also can affect both vertebrate and invertebrate hosts in ways that significantly alter patterns of virus transmission. This chapter concentrates on selected components of the virus-vector-vertebrate interrelationship, focusing specifically on how interactions between vector, virus, and environment shape the patterns and intensity of WNV transmission.

Vector-Virus Interactions and Transmission Dynamics of West Nile Virus

PubMed Central

Ciota, Alexander T.; Kramer, Laura D.

2013-01-01

West Nile virus (WNV; Flavivirus; Flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. Mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. The concept of vectorial capacity integrates these factors to address interactions of the virus with the arthropod host, leading to a clearer understanding of their complex interrelationships, how they affect transmission of vector-borne disease, and how they impact human health. Vertebrate factors including host competence, population dynamics, and immune status also affect transmission dynamics. The complexity of these interactions are further exacerbated by the fact that not only can divergent hosts differentially alter the virus, but the virus also can affect both vertebrate and invertebrate hosts in ways that significantly alter patterns of virus transmission. This chapter concentrates on selected components of the virus-vector-vertebrate interrelationship, focusing specifically on how interactions between vector, virus, and environment shape the patterns and intensity of WNV transmission. PMID:24351794

Daily Stress, Coping, and Negative and Positive Affect in Depression: Complex Trigger and Maintenance Patterns.

PubMed

Dunkley, David M; Lewkowski, Maxim; Lee, Ihno A; Preacher, Kristopher J; Zuroff, David C; Berg, Jody-Lynn; Foley, J Elizabeth; Myhr, Gail; Westreich, Ruta

2017-05-01

Major depressive disorder is characterized by emotional dysfunction, but mood states in daily life are not well understood. This study examined complex explanatory models of daily stress and coping mechanisms that trigger and maintain daily negative affect and (lower) positive affect in depression. Sixty-three depressed patients completed perfectionism measures, and then completed daily questionnaires of stress appraisals, coping, and affect for 7 consecutive days. Multilevel structural equation modeling (MSEM) demonstrated that, across many stressors, when the typical individual with depression perceives more criticism than usual, he/she uses more avoidant coping and experiences higher event stress than usual, and this is connected to daily increases in negative affect as well as decreases in positive affect. In parallel, results showed that perceived control, less avoidant coping, and problem-focused coping commonly operate together when daily positive affect increases. MSEM also showed that avoidant coping tendencies and ongoing stress, in combination, explain why people with depression and higher self-critical perfectionism maintain daily negative affect and lower positive affect. These findings advance a richer and more detailed understanding of specific stress and coping patterns to target in order to more effectively accomplish the two predominant therapy goals of decreasing patients' distress and strengthening resilience. Copyright © 2016. Published by Elsevier Ltd.

Differential effects of habitat complexity, predators and competitors on abundance of juvenile and adult coral reef fishes.

PubMed

Almany, Glenn R

2004-09-01

Greater structural complexity is often associated with greater abundance and diversity, perhaps because high complexity habitats reduce predation and competition. Using 16 spatially isolated live-coral reefs in the Bahamas, I examined how abundance of juvenile (recruit) and adult (non-recruit) fishes was affected by two factors: (1) structural habitat complexity and (2) the presence of predators and interference competitors. Manipulating the abundance of low and high complexity corals created two levels of habitat complexity, which was cross-factored with the presence or absence of resident predators (sea basses and moray eels) plus interference competitors (territorial damselfishes). Over 60 days, predators and competitors greatly reduced recruit abundance regardless of habitat complexity, but did not affect adult abundance. In contrast, increased habitat complexity had a strong positive effect on adult abundance and a weak positive effect on recruit abundance. Differential responses of recruits and adults may be related to the differential effects of habitat complexity on their primary predators. Sedentary recruits are likely most preyed upon by small resident predators that ambush prey, while larger adult fishes that forage widely and use reefs primarily for shelter are likely most preyed upon by large transient predators that chase prey. Increased habitat complexity may have inhibited foraging by transient predators but not resident predators. Results demonstrate the importance of habitat complexity to community dynamics, which is of concern given the accelerated degradation of habitats worldwide.

Driver Expectations When Navigating Complex Interchanges

DOT National Transportation Integrated Search

2013-10-01

The purpose of this project was to develop a method for determining driver expectations at interchanges and to use that method to determine how these expectations affect driver behavior at interchanges that vary in level of complexity, including prov...

Paleogeographic controls of coal accumulation, Cretaceous Blackhawk Formation and Star Point Sandstone, Wasatch Plateau, Utah.

USGS Publications Warehouse

Flores, R.M.; Blanchard, L.F.; Sanchez, J.D.; Marley, W.E.; Muldoon, W.J.

1984-01-01

Considers the paleogeographic controls affecting the accumulation of coals in delta-barrier-island complexes. Progradation, lateral shifting, and abandonment of these complexes created four major landward-thinning tongues.-from Authors

Surface complexation modeling

USDA-ARS?s Scientific Manuscript database

Adsorption-desorption reactions are important processes that affect the transport of contaminants in the environment. Surface complexation models are chemical models that can account for the effects of variable chemical conditions, such as pH, on adsorption reactions. These models define specific ...

A global view of atmospheric ice particle complexity

NASA Astrophysics Data System (ADS)

Schmitt, Carl G.; Heymsfield, Andrew J.; Connolly, Paul; Järvinen, Emma; Schnaiter, Martin

2016-11-01

Atmospheric ice particles exist in a variety of shapes and sizes. Single hexagonal crystals like common hexagonal plates and columns are possible, but more frequently, atmospheric ice particles are much more complex. Ice particle shapes have a substantial impact on many atmospheric processes through fall speed, affecting cloud lifetime, to radiative properties, affecting energy balance to name a few. This publication builds on earlier work where a technique was demonstrated to separate single crystals and aggregates of crystals using particle imagery data from aircraft field campaigns. Here data from 10 field programs have been analyzed and ice particle complexity parameterized by cloud temperature for arctic, midlatitude (summer and frontal), and tropical cloud systems. Results show that the transition from simple to complex particles can be as small as 80 µm or as large as 400 µm depending on conditions. All regimes show trends of decreasing transition size with decreasing temperature.

Interpretation of Statistical Data: The Importance of Affective Expressions

ERIC Educational Resources Information Center

Queiroz, Tamires; Monteiro, Carlos; Carvalho, Liliane; François, Karen

2017-01-01

In recent years, research on teaching and learning of statistics emphasized that the interpretation of data is a complex process that involves cognitive and technical aspects. However, it is a human activity that involves also contextual and affective aspects. This view is in line with research on affectivity and cognition. While the affective…

Affective and Cardiovascular Responding to Unpleasant Events from Adolescence to Old Age: Complexity of Events Matters

ERIC Educational Resources Information Center

Wrzus, Cornelia; Muller, Viktor; Wagner, Gert G.; Lindenberger, Ulman; Riediger, Michaela

2013-01-01

Two studies investigated the "overpowering hypothesis" as a possible explanation for the currently inconclusive empirical picture on age differences in affective responding to unpleasant events. The overpowering hypothesis predicts that age differences in affective responding are particularly evident in highly resource-demanding situations that…

Preparation and properties of chitosan-metal complex: Some factors influencing the adsorption capacity for dyes in aqueous solution.

PubMed

Rashid, Sadia; Shen, Chensi; Yang, Jing; Liu, Jianshe; Li, Jing

2018-04-01

Chitosan-metal complexes have been widely studied in wastewater treatment, but there are still various factors in complex preparation which are collectively responsible for improving the adsorption capacity need to be further studied. Thus, this study investigates the factors affecting the adsorption ability of chitosan-metal complex adsorbents, including various kinds of metal centers, different metal salts and crosslinking degree. The results show that the chitosan-Fe(III) complex prepared by sulfate salts exhibited the best adsorption efficiency (100%) for various dyes in very short time duration (10min), and its maximum adsorption capacity achieved 349.22mg/g. The anion of the metal salt which was used in preparation played an important role to enhance the adsorption ability of chitosan-metal complex. SO 4 2- ions not only had the effect of crosslinking through electrostatic interaction with amine group of chitosan polymer, but also could facilitate the chelation of metal ions with chitosan polymer during the synthesis process. Additionally, the pH sensitivity and the sensitivity of ionic environment for chitosan-metal complex were analyzed. We hope that these factors affecting the adsorption of the chitosan-metal complex can help not only in optimizing its use but also in designing new chitosan-metal based complexes. Copyright © 2017. Published by Elsevier B.V.

Factors Affecting Police Officers' Acceptance of GIS Technologies: A Study of the Turkish National Police

ERIC Educational Resources Information Center

Cakar, Bekir

2011-01-01

The situations and problems that police officers face are more complex in today's society, due in part to the increase of technology and growing complexity of globalization. Accordingly, to solve these problems and deal with the complexities, law enforcement organizations develop and apply new techniques and methods such as geographic information…

Measuring Search Efficiency in Complex Visual Search Tasks: Global and Local Clutter

ERIC Educational Resources Information Center

Beck, Melissa R.; Lohrenz, Maura C.; Trafton, J. Gregory

2010-01-01

Set size and crowding affect search efficiency by limiting attention for recognition and attention against competition; however, these factors can be difficult to quantify in complex search tasks. The current experiments use a quantitative measure of the amount and variability of visual information (i.e., clutter) in highly complex stimuli (i.e.,…

Deconstructing the simplification of jury instructions: How simplifying the features of complexity affects jurors' application of instructions.

PubMed

Baguley, Chantelle M; McKimmie, Blake M; Masser, Barbara M

2017-06-01

Research consistently shows that techniques currently used to simplify jury instructions do not always improve mock jurors' comprehension. If improvements are observed, these are limited and overall comprehension remains low. It is unclear, however, why this occurs. It is possible that current simplification techniques do not effectively simplify the features of complexity, present in standardized instructions, which have the greatest effect on jurors' comprehension. It is not yet known, however, how much each feature of complexity individually affects jurors' comprehension. To investigate this, the authors used existing data from published empirical studies to examine how simplifying each feature of complexity affects mock jurors' application of instructions, as jurors can only apply instructions to the extent they understand them. The results suggest that reducing the conceptual complexity and proportion of supplementary information was associated with increased application of the instructions; however, reducing both the linguistic complexity and amount of information, and providing the instructions in a written format was not. In addition, results showed an unexpected adverse effect of simplification-reducing the amount of information was associated with an increase in the punitiveness of mock jurors' verdicts, independently of the instruction content. Together, these results suggest a need to make jury instructions comprehensible, highlight the key principles in the decision-process, and identify a way to eliminate the negative effect of reducing the amount of information. Addressing these needs is essential for developing a simplification technique that maximizes jurors' comprehension and application of instructions, while minimizing the previously overlooked negative effects of simplification. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

SMC condensation centers in Bacillus subtilis are dynamic structures.

PubMed

Kleine Borgmann, Luise A K; Hummel, Hanna; Ulbrich, Maximilian H; Graumann, Peter L

2013-05-01

SMC and MukB complexes consist of a central SMC dimer and two essential binding partners, ScpA and ScpB (MukE and MukF), and are crucial for correct chromosome compaction and segregation. The complexes form two bipolar assemblies on the chromosome, one in each cell half. Using fluorescence recovery after photobleaching (FRAP), we provide evidence that the SMC complex has high exchange rates. This depends to a considerable degree on de novo protein synthesis, revealing that the bacterial SMC complex has high on and off rates for binding to the chromosome. A mutation in SMC that affects ATPase activity and results in exaggerated DNA binding in vitro causes a strong segregation defect in vivo and affects the localization of the entire SMC complex, which localizes to many more sites in the cell than under normal conditions. These data indicate that ATP turnover is important for the function of Bacillus subtilis SMC. In contrast, the centromere protein Spo0J and DNA gyrase showed much less exchange between distinct binding sites on the chromosome than that seen with SMC. Binding of Spo0J to the origin regions was rather static and remained partially conserved until the next cell cycle. Our experiments reveal that the SMC complex has a high, condensin-like turnover rate and that an alteration of the ATPase cycle affects SMC function in vivo, while several nucleoid-associated proteins feature limited or slow exchange between different sites on the nucleoid, which may be the basis for epigenetic-like phenomena observed in bacteria.

Fault kinematics and localised inversion within the Troms-Finnmark Fault Complex, SW Barents Sea

NASA Astrophysics Data System (ADS)

Zervas, I.; Omosanya, K. O.; Lippard, S. J.; Johansen, S. E.

2018-04-01

The areas bounding the Troms-Finnmark Fault Complex are affected by complex tectonic evolution. In this work, the history of fault growth, reactivation, and inversion of major faults in the Troms-Finnmark Fault Complex and the Ringvassøy Loppa Fault Complex is interpreted from three-dimensional seismic data, structural maps and fault displacement plots. Our results reveal eight normal faults bounding rotated fault blocks in the Troms-Finnmark Fault Complex. Both the throw-depth and displacement-distance plots show that the faults exhibit complex configurations of lateral and vertical segmentation with varied profiles. Some of the faults were reactivated by dip-linkages during the Late Jurassic and exhibit polycyclic fault growth, including radial, syn-sedimentary, and hybrid propagation. Localised positive inversion is the main mechanism of fault reactivation occurring at the Troms-Finnmark Fault Complex. The observed structural styles include folds associated with extensional faults, folded growth wedges and inverted depocentres. Localised inversion was intermittent with rifting during the Middle Jurassic-Early Cretaceous at the boundaries of the Troms-Finnmark Fault Complex to the Finnmark Platform. Additionally, tectonic inversion was more intense at the boundaries of the two fault complexes, affecting Middle Triassic to Early Cretaceous strata. Our study shows that localised folding is either a product of compressional forces or of lateral movements in the Troms-Finnmark Fault Complex. Regional stresses due to the uplift in the Loppa High and halokinesis in the Tromsø Basin are likely additional causes of inversion in the Troms-Finnmark Fault Complex.

Interspecies Systems Biology Uncovers Metabolites Affecting C. elegans Gene Expression and Life History Traits

PubMed Central

Watson, Emma; MacNeil, Lesley T.; Ritter, Ashlyn D.; Yilmaz, L. Safak; Rosebrock, Adam P.; Caudy, Amy A.; Walhout, Albertha J. M.

2014-01-01

SUMMARY Diet greatly influences gene expression and physiology. In mammals, elucidating the effects and mechanisms of individual nutrients is challenging due to the complexity of both the animal and its diet. Here we used an interspecies systems biology approach with Caenorhabditis elegans and two if its bacterial diets, Escherichia coli and Comamonas aquatica, to identify metabolites that affect the animal’s gene expression and physiology. We identify vitamin B12 as the major dilutable metabolite provided by Comamonas aq. that regulates gene expression, accelerates development and reduces fertility, but does not affect lifespan. We find that vitamin B12 has a dual role in the animal: it affects development and fertility via the methionine/S-Adenosylmethionine (SAM) cycle and breaks down the short-chain fatty acid propionic acid preventing its toxic buildup. Our interspecies systems biology approach provides a paradigm for understanding complex interactions between diet and physiology. PMID:24529378

Syntheses, structures and photoelectric properties of a series of Cd(II)/Zn(II) coordination polymers and coordination supramolecules

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin Jing; Han Xiao; Meng Qin

2013-01-15

Five Cd(II)/Zn(II) complexes [Cd(1,2-bdc)(pz){sub 2}(H{sub 2}O)]{sub n} (1), [Cd1Cd2(btec)(H{sub 2}O){sub 6}]{sub n} (2), [Cd(3,4-pdc) (H{sub 2}O)]{sub n} (3), [Zn(2,5-pdc)(H{sub 2}O){sub 4}]{center_dot}2H{sub 2}O (4) and {l_brace} [Zn(2,5-pdc)(H{sub 2}O){sub 2}]{center_dot}H{sub 2}O{r_brace} {sub n} (5) (H{sub 2}bdc=1,2-benzenedicarboxylic acid, pz=pyrazole, H{sub 4}btec=1,2,4,5-benzenetetracarboxylic acid, H{sub 2}pdc=pyridine-dicarboxylic acid) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction, surface photovoltage spectroscopy, XRD, TG analysis, IR and UV-vis spectra and elemental analysis. Structural analyses show that complexes 1-3 are 1D, 2D and 3D Cd(II) coordination polymers, respectively. Complex 4 is a mononuclear Zn(II) complex. Complex 5 is a 3D Zn(II) coordination polymer. The surface photoelectric properties of complexesmore » were investigated by SPS. The results indicate that all complexes exhibit photoelectric responses in the range of 300-600 nm, which reveals that they all possess certain photoelectric conversion properties. By the comparative analyses, it can be found that the species and coordination micro-environment of central metal ion, the species and property of ligands affect the intensity and scope of photoelectric response. - Graphical abstract: Five Cd(II)/Zn(II) complexes have been hydrothermally synthesized and characterized. The photoelectric properties were studied with SPS. The species and coordination micro-environment of central metal ion, the species and property of ligands all affect the photoelectric responses. Highlights: Black-Right-Pointing-Pointer Five Cd/Zn complexes have been synthesized and characterized. Black-Right-Pointing-Pointer The SPS results indicate they possess obvious photoelectric conversion property. Black-Right-Pointing-Pointer The species and coordination environment of central metal ion affect SPS. Black-Right-Pointing-Pointer The species and property of ligands affect SPS. Black-Right-Pointing-Pointer By the energy-band theory and the crystal filed theory, the SPS are analyzed and assigned.« less

They Learn the CLIL Way, but Do They Like It? Affectivity and Cognition in Upper-Primary CLIL Classes

ERIC Educational Resources Information Center

Otwinowska, Agnieszka; Forys, Malgorzata

2017-01-01

CLIL (Content and Language Integrated Learning) is a teaching method in which learners develop linguistic competence and problem-solving abilities by learning content subjects in another language. However, learners' cognitive gains may depend on their affectivity. Negative affect hampers complex cognitive processing essential for problem-solving,…

Promyelocytic Leukemia Protein, a Protein at the Crossroad of Oxidative Stress and Metabolism.

PubMed

Tessier, Sarah; Martin-Martin, Natalia; de Thé, Hugues; Carracedo, Arkaitz; Lallemand-Breitenbach, Valérie

2017-03-20

Cellular metabolic activity impacts the production of reactive oxygen species (ROS), both positively through mitochondrial oxidative processes and negatively by promoting the production of reducing agents (including NADPH and reduced glutathione). A defined metabolic state in cancer cells is critical for cell growth and long-term self-renewal, and such state is intrinsically associated with redox balance. Promyelocytic leukemia protein (PML) regulates several biological processes, at least in part, through its ability to control the assembly of PML nuclear bodies (PML NBs). Recent Advances: PML is oxidation-prone, and oxidative stress promotes NB biogenesis. These nuclear subdomains recruit many nuclear proteins and regulate their SUMOylation and other post-translational modifications. Some of these cargos-such as p53, SIRT1, AKT, and mammalian target of rapamycin (mTOR)-are key regulators of cell fate. PML was also recently shown to regulate oxidation. While it was long considered primarily as a tumor suppressor protein, PML-regulated metabolic switch uncovered that this protein could promote survival and/or stemness of some normal or cancer cells. In this study, we review the recent findings on this multifunctional protein. Studying PML scaffolding functions as well as its fine role in the activation of p53 or fatty acid oxidation will bring new insights in how PML could bridge oxidative stress, senescence, cell death, and metabolism. Antioxid. Redox Signal. 26, 432-444.

Comprehensive Gene expression meta-analysis and integrated bioinformatic approaches reveal shared signatures between thrombosis and myeloproliferative disorders

PubMed Central

Jha, Prabhash Kumar; Vijay, Aatira; Sahu, Anita; Ashraf, Mohammad Zahid

2016-01-01

Thrombosis is a leading cause of morbidity and mortality in patients with myeloproliferative disorders (MPDs), particularly polycythemia vera (PV) and essential thrombocythemia (ET). Despite the attempts to establish a link between them, the shared biological mechanisms are yet to be characterized. An integrated gene expression meta-analysis of five independent publicly available microarray data of the three diseases was conducted to identify shared gene expression signatures and overlapping biological processes. Using INMEX bioinformatic tool, based on combined Effect Size (ES) approaches, we identified a total of 1,157 differentially expressed genes (DEGs) (697 overexpressed and 460 underexpressed genes) shared between the three diseases. EnrichR tool’s rich library was used for comprehensive functional enrichment and pathway analysis which revealed “mRNA Splicing” and “SUMO E3 ligases SUMOylate target proteins” among the most enriched terms. Network based meta-analysis identified MYC and FN1 to be the most highly ranked hub genes. Our results reveal that the alterations in biomarkers of the coagulation cascade like F2R, PROS1, SELPLG and ITGB2 were common between the three diseases. Interestingly, the study has generated a novel database of candidate genetic markers, pathways and transcription factors shared between thrombosis and MPDs, which might aid in the development of prognostic therapeutic biomarkers. PMID:27892526

Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin

PubMed Central

Oulhen, Nathalie; Wessel, Gary M.

2016-01-01

Nanos is a translational regulator required for the survival and maintenance of primordial germ cells. In the sea urchin, Strongylocentrotus purpuratus (Sp), Nanos 2 mRNA is broadly transcribed but accumulates specifically in the small micromere (sMic) lineage, in part because of the 3′UTR element GNARLE leads to turnover in somatic cells but retention in the sMics. Here we found that the Nanos 2 protein is also selectively stabilized; it is initially translated throughout the embryo but turned over in the future somatic cells and retained only in the sMics, the future germ line in this animal. This differential stability of Nanos protein is dependent on the open reading frame (ORF), and is independent of the sumoylation and ubiquitylation pathways. Manipulation of the ORF indicates that 68 amino acids in the N terminus of the Nanos protein are essential for its stability in the sMics whereas a 45 amino acid element adjacent to the zinc fingers targets its degradation. Further, this regulation of Nanos protein is cell autonomous, following formation of the germ line. These results are paradigmatic for the unique presence of Nanos in the germ line by a combination of selective RNA retention, distinctive translational control mechanisms (Oulhen et al., 2013), and now also by defined Nanos protein stability. PMID:27424271

Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.

PubMed

Oulhen, Nathalie; Wessel, Gary M

2016-10-01

Nanos is a translational regulator required for the survival and maintenance of primordial germ cells. In the sea urchin, Strongylocentrotus purpuratus (Sp), Nanos 2 mRNA is broadly transcribed but accumulates specifically in the small micromere (sMic) lineage, in part because of the 3'UTR element GNARLE leads to turnover in somatic cells but retention in the sMics. Here we found that the Nanos 2 protein is also selectively stabilized; it is initially translated throughout the embryo but turned over in the future somatic cells and retained only in the sMics, the future germ line in this animal. This differential stability of Nanos protein is dependent on the open reading frame (ORF), and is independent of the sumoylation and ubiquitylation pathways. Manipulation of the ORF indicates that 68 amino acids in the N terminus of the Nanos protein are essential for its stability in the sMics whereas a 45 amino acid element adjacent to the zinc fingers targets its degradation. Further, this regulation of Nanos protein is cell autonomous, following formation of the germ line. These results are paradigmatic for the unique presence of Nanos in the germ line by a combination of selective RNA retention, distinctive translational control mechanisms (Oulhen et al., 2013), and now also by defined Nanos protein stability. Copyright © 2016 Elsevier Inc. All rights reserved.

Phenotypic characterization of nevus and tumor patterns in MITF E318K mutation carrier melanoma patients.

PubMed

Sturm, Richard A; Fox, Carly; McClenahan, Phil; Jagirdar, Kasturee; Ibarrola-Villava, Maider; Banan, Parastoo; Abbott, Nicola C; Ribas, Gloria; Gabrielli, Brian; Duffy, David L; Peter Soyer, H

2014-01-01

A germline polymorphism of the microphthalmia transcription factor (MITF) gene encoding a SUMOylation-deficient E318K-mutated protein has recently been described as a medium-penetrance melanoma gene. In a clinical assessment of nevi from 301 volunteers taken from Queensland, we identified six individuals as MITF E318K mutation carriers. The phenotype for 5 of these individuals showed a commonality of fair skin, body freckling that varied over a wide range, and total nevus count between 46 and 430; in addition, all were multiple primary melanoma patients. The predominant dermoscopic signature pattern of nevi was reticular, and the frequency of globular nevi in carriers varied, which does not suggest that the MITF E318K mutation acts to force the continuous growth of nevi. Excised melanocytic lesions were available for four MITF E318K carrier patients and were compared with a matched range of wild-type (WT) melanocytic lesions. The MITF staining pattern showed a predominant nuclear signal in all sections, with no significant difference in the nuclear/cytoplasmic ratio between mutation-positive or -negative samples. A high incidence of amelanotic melanomas was found within the group, with three of the five melanomas from one patient suggesting a genetic interaction between the MITF E318K allele and an MC1R homozygous red hair color (RHC) variant genotype.

SIRT1 inhibits EV71 genome replication and RNA translation by interfering with the viral polymerase and 5′UTR RNA

PubMed Central

Han, Yang; Wang, Lvyin; Cui, Jin; Song, Yu; Luo, Zhen; Chen, Junbo; Xiong, Ying; Zhang, Qi; Liu, Fang; Ho, Wenzhe; Liu, Yingle; Wu, Jianguo

2016-01-01

ABSTRACT Enterovirus 71 (EV71) possesses a single-stranded positive RNA genome that contains a single open reading frame (ORF) flanked by a 5′ untranslated region (5′UTR) and a polyadenylated 3′UTR. Here, we demonstrated that EV71 activates the production of silent mating type information regulation 2 homolog 1 (SIRT1), a histone deacetylase (HDAC). EV71 further stimulates SIRT1 sumoylation and deacetylase activity, and enhances SIRT1 translocation from the nucleus to the cytoplasm. More interestingly, activated SIRT1 subsequently binds with the EV71 3Dpol protein (a viral RNA-dependent RNA polymerase, RdRp) to repress the acetylation and RdRp activity of 3Dpol, resulting in the attenuation of viral genome replication. Moreover, SIRT1 interacts with the cloverleaf structure of the EV71 RNA 5′UTR to inhibit viral RNA transcription, and binds to the internal ribosome entry site (IRES) of the EV71 5′UTR to attenuate viral RNA translation. Thus, EV71 stimulates SIRT1 production and activity, which in turn represses EV71 genome replication by inhibiting viral polymerase, and attenuates EV71 RNA transcription and translation by interfering with viral RNA. These results uncover a new function of SIRT1 and reveal a new mechanism underlying the regulation of EV71 replication. PMID:27875274

Catalytic Hydroamination of Alkynes and Norbornene with Neutral and Cationic Tantalum Imido Complexes

PubMed Central

Anderson, Laura L.; Arnold, John; Bergman, Robert G.

2005-01-01

Several tantalum imido complexes have been synthesized and shown to efficiently catalyze the hydroamination of internal and terminal alkynes. An unusual hydroamination/hydroarylation reaction of norbornene catalyzed by a highly electrophilic cationic tantalum imido complex is also reported. Factors affecting catalyst activity and selectivity are discussed along with mechanistic insights gained from stoichiometric reactions. PMID:15255680

RNA editing of microRNA prevents RNA-induced silencing complex recognition of target mRNA.

PubMed

Cui, Yalei; Huang, Tianzhi; Zhang, Xiaobo

2015-12-01

MicroRNAs (miRNAs) integrate with Argonaut (Ago) to create the RNA-induced silencing complex, and regulate gene expression by silencing target mRNAs. RNA editing of miRNA may affect miRNA processing, assembly of the Ago complex and target mRNA binding. However, the function of edited miRNA, assembled within the Ago complex, has not been extensively investigated. In this study, sequence analysis of the Ago complex of Marsupenaeus japonicus shrimp infected with white spot syndrome virus (WSSV) revealed that host ADAR (adenosine deaminase acting on RNA) catalysed A-to-I RNA editing of a viral miRNA (WSSV-miR-N12) at the +16 site. This editing of the non-seed sequence did not affect association of the edited miRNA with the Ago protein, but inhibited interaction between the miRNA and its target gene (wsv399). The WSSV early gene wsv399 inhibited WSSV infection. As a result, the RNA editing of miRNA caused virus latency. Our results highlight a novel example of miRNA editing in the miRNA-induced silencing complex. © 2015 The Authors.

The Dynamics of the Human Leukocyte Antigen Head Domain Modulates Its Recognition by the T-Cell Receptor.

PubMed

García-Guerrero, Estefanía; Pérez-Simón, José Antonio; Sánchez-Abarca, Luis Ignacio; Díaz-Moreno, Irene; De la Rosa, Miguel A; Díaz-Quintana, Antonio

2016-01-01

Generating the immune response requires the discrimination of peptides presented by the human leukocyte antigen complex (HLA) through the T-cell receptor (TCR). However, how a single amino acid substitution in the antigen bonded to HLA affects the response of T cells remains uncertain. Hence, we used molecular dynamics computations to analyze the molecular interactions between peptides, HLA and TCR. We compared immunologically reactive complexes with non-reactive and weakly reactive complexes. MD trajectories were produced to simulate the behavior of isolated components of the various p-HLA-TCR complexes. Analysis of the fluctuations showed that p-HLA binding barely restrains TCR motions, and mainly affects the CDR3 loops. Conversely, inactive p-HLA complexes displayed significant drop in their dynamics when compared with its free versus ternary forms (p-HLA-TCR). In agreement, the free non-reactive p-HLA complexes showed a lower amount of salt bridges than the responsive ones. This resulted in differences between the electrostatic potentials of reactive and inactive p-HLA species and larger vibrational entropies in non-elicitor complexes. Analysis of the ternary p-HLA-TCR complexes also revealed a larger number of salt bridges in the responsive complexes. To summarize, our computations indicate that the affinity of each p-HLA complex towards TCR is intimately linked to both, the dynamics of its free species and its ability to form specific intermolecular salt-bridges in the ternary complexes. Of outstanding interest is the emerging concept of antigen reactivity involving its interplay with the HLA head sidechain dynamics by rearranging its salt-bridges.

Overexpression of Promyelocytic Leukemia Protein Precludes the Dispersal of ND10 Structures and Has No Effect on Accumulation of Infectious Herpes Simplex Virus 1 or Its Proteins

PubMed Central

Lopez, Pascal; Jacob, Robert J.; Roizman, Bernard

2002-01-01

A key early event in the replication of herpes simplex virus 1 (HSV-1) is the localization of infected-cell protein no. 0 (ICP0) in nuclear structures knows as ND10 or promyelocytic leukemia oncogenic domains (PODs). This is followed by dispersal of ND10 constituents such as the promyelocytic leukemia protein (PML), CREB-binding protein (CBP), and Daxx. Numerous experiments have shown that this dispersal is mediated by ICP0. PML is thought to be the organizing structural component of ND10. To determine whether the virus targets PML because it is inimical to viral replication, telomerase-immortalized human foreskin fibroblasts and HEp-2 cells were transduced with wild-type baculovirus or a baculovirus expressing the Mr 69,000 form of PML. The transduced cultures were examined for expression and localization of PML in mock-infected and HSV-1-infected cells. The results obtained from studies of cells overexpressing PML were as follows. (i) Transduced cells accumulate large amounts of unmodified and SUMO-I-modified PML. (ii) Mock-infected cells exhibited enlarged ND10 structures containing CBP and Daxx in addition to PML. (iii) In infected cells, ICP0 colocalized with PML in ND10 early in infection, but the two proteins did not overlap or were juxtaposed in orderly structures. (iv) The enlarged ND10 structures remained intact at least until 12 h after infection and retained CBP and Daxx in addition to PML. (v) Overexpression of PML had no effect on the accumulation of viral proteins representative of α, β, or γ groups and had no effect on the accumulation of infectious virus in cells infected with wild-type virus or a mutant (R7910) from which the α0 genes had been deleted. These results indicate the following: (i) PML overexpressed in transduced cells cannot be differentiated from endogenous PML with respect to sumoylation and localization in ND10 structures. (ii) PML does not affect viral replication or the changes in the localization of ICP0 through infection. (iii) Disaggregation of ND10 structures is not an obligatory event essential for viral replication. PMID:12186918

The absence of chlorophyll b affects lateral mobility of photosynthetic complexes and lipids in grana membranes of Arabidopsis and barley chlorina mutants.

PubMed

Tyutereva, Elena V; Evkaikina, Anastasiia I; Ivanova, Alexandra N; Voitsekhovskaja, Olga V

2017-09-01

The lateral mobility of integral components of thylakoid membranes, such as plastoquinone, xanthophylls, and pigment-protein complexes, is critical for the maintenance of efficient light harvesting, high rates of linear electron transport, and successful repair of damaged photosystem II (PSII). The packaging of the photosynthetic pigment-protein complexes in the membrane depends on their size and stereometric parameters which in turn depend on the composition of the complexes. Chlorophyll b (Chlb) is an important regulator of antenna size and composition. In this study, the lateral mobility (the mobile fraction size) of pigment-protein complexes and lipids in grana membranes was analyzed in chlorina mutants of Arabidopsis and barley lacking Chlb. In the Arabidopsis ch1-3 mutant, diffusion of membrane lipids decreased as compared to wild-type plants, but the diffusion of photosynthetic complexes was not affected. In the barley chlorina f2 3613 mutant, the diffusion of pigment-protein complexes significantly decreased, while the diffusion of lipids increased, as compared to wild-type plants. We propose that the size of the mobile fractions of pigment-protein complexes in grana membranes in vivo is higher than reported previously. The data are discussed in the context of the protein composition of antennae, characteristics of the plastoquinone pool, and production of reactive oxygen species in leaves of chlorina mutants.

A study on axial and torsional resonant mode matching for a mechanical system with complex nonlinear geometries

NASA Astrophysics Data System (ADS)

Watson, Brett; Yeo, Leslie; Friend, James

2010-06-01

Making use of mechanical resonance has many benefits for the design of microscale devices. A key to successfully incorporating this phenomenon in the design of a device is to understand how the resonant frequencies of interest are affected by changes to the geometric parameters of the design. For simple geometric shapes, this is quite easy, but for complex nonlinear designs, it becomes significantly more complex. In this paper, two novel modeling techniques are demonstrated to extract the axial and torsional resonant frequencies of a complex nonlinear geometry. The first decomposes the complex geometry into easy to model components, while the second uses scaling techniques combined with the finite element method. Both models overcome problems associated with using current analytical methods as design tools, and enable a full investigation of how changes in the geometric parameters affect the resonant frequencies of interest. The benefit of such models is then demonstrated through their use in the design of a prototype piezoelectric ultrasonic resonant micromotor which has improved performance characteristics over previous prototypes.

Mutations in the gene encoding the Sigma 2 subunit of the adaptor protein 1 complex, AP1S2, cause X-linked mental retardation.

PubMed

Tarpey, Patrick S; Stevens, Claire; Teague, Jon; Edkins, Sarah; O'Meara, Sarah; Avis, Tim; Barthorpe, Syd; Buck, Gemma; Butler, Adam; Cole, Jennifer; Dicks, Ed; Gray, Kristian; Halliday, Kelly; Harrison, Rachel; Hills, Katy; Hinton, Jonathon; Jones, David; Menzies, Andrew; Mironenko, Tatiana; Perry, Janet; Raine, Keiran; Richardson, David; Shepherd, Rebecca; Small, Alexandra; Tofts, Calli; Varian, Jennifer; West, Sofie; Widaa, Sara; Yates, Andy; Catford, Rachael; Butler, Julia; Mallya, Uma; Moon, Jenny; Luo, Ying; Dorkins, Huw; Thompson, Deborah; Easton, Douglas F; Wooster, Richard; Bobrow, Martin; Carpenter, Nancy; Simensen, Richard J; Schwartz, Charles E; Stevenson, Roger E; Turner, Gillian; Partington, Michael; Gecz, Jozef; Stratton, Michael R; Futreal, P Andrew; Raymond, F Lucy

2006-12-01

In a systematic sequencing screen of the coding exons of the X chromosome in 250 families with X-linked mental retardation (XLMR), we identified two nonsense mutations and one consensus splice-site mutation in the AP1S2 gene on Xp22 in three families. Affected individuals in these families showed mild-to-profound mental retardation. Other features included hypotonia early in life and delay in walking. AP1S2 encodes an adaptin protein that constitutes part of the adaptor protein complex found at the cytoplasmic face of coated vesicles located at the Golgi complex. The complex mediates the recruitment of clathrin to the vesicle membrane. Aberrant endocytic processing through disruption of adaptor protein complexes is likely to result from the AP1S2 mutations identified in the three XLMR-affected families, and such defects may plausibly cause abnormal synaptic development and function. AP1S2 is the first reported XLMR gene that encodes a protein directly involved in the assembly of endocytic vesicles.

Protein complex could be key to drug responsiveness in lymphoma patients | Center for Cancer Research

Cancer.gov

Continuing a decades-long refinement in understanding how and why a drug is more effective in some patients with lymphoma than others has led to the discovery of a complex of proteins that affects drug responsiveness.

Evidence from pupillometry and fMRI indicates reduced neural response during vicarious social pain but not physical pain in autism.

PubMed

Krach, Sören; Kamp-Becker, Inge; Einhäuser, Wolfgang; Sommer, Jens; Frässle, Stefan; Jansen, Andreas; Rademacher, Lena; Müller-Pinzler, Laura; Gazzola, Valeria; Paulus, Frieder M

2015-11-01

Autism spectrum disorder (ASD) is characterized by substantial social deficits. The notion that dysfunctions in neural circuits involved in sharing another's affect explain these deficits is appealing, but has received only modest experimental support. Here we evaluated a complex paradigm on the vicarious social pain of embarrassment to probe social deficits in ASD as to whether it is more potent than paradigms currently in use. To do so we acquired pupillometry and fMRI in young adults with ASD and matched healthy controls. During a simple vicarious physical pain task no differences emerged between groups in behavior, pupillometry, and neural activation of the anterior insula (AIC) and anterior cingulate cortex (ACC). In contrast, processing complex vicarious social pain yielded reduced responses in ASD on all physiological measures of sharing another's affect. The reduced activity within the AIC was thereby explained by the severity of autistic symptoms in the social and affective domain. Additionally, behavioral responses lacked correspondence with the anterior cingulate and anterior insula cortex activity found in controls. Instead, behavioral responses in ASD were associated with hippocampal activity. The observed dissociation echoes the clinical observations that deficits in ASD are most pronounced in complex social situations and simple tasks may not probe the dysfunctions in neural pathways involved in sharing affect. Our results are highly relevant because individuals with ASD may have preserved abilities to share another's physical pain but still have problems with the vicarious representation of more complex emotions that matter in life. © 2015 Wiley Periodicals, Inc.

On duty all the time: health and quality of life among immigrant parents caring for a child with complex health needs.

PubMed

Gravdal Kvarme, Lisbeth; Albertini-Früh, Elena; Brekke, Idunn; Gardsjord, Ragnhild; Halvorsrud, Liv; Liden, Hilde

2016-02-01

To provide knowledge about how immigrant parents of children with complex health needs manage their family lives and how this affects their own health and quality of life. Caregivers of children with complex health needs have additional risk for general health problems and mental health problems and immigrant parents may be more vulnerable to mental distress and failing health and quality of life. This qualitative study used an exploratory design with individual and focus group interviews. Data collection and analysis followed phenomenological hermeneutic guidelines. Individual and group interviews with 27 parents: 18 mothers and 9 fathers from Pakistan, Poland and Vietnam. Immigrant parents of children with complex health needs experience their own health and quality of life challenges. They described the burden of dealing with their child's needs and special care, which affects their sleep and physical and mental health. Single mothers are particularly vulnerable. Parents reported positive and negative effects of their caregiving experience that may affect their health and quality of life. Mothers were the primary caregivers and reported more health problems than did fathers. The lack of respite care, social networks and support impacted maternal health. Immigrant parents struggle to access resources for their child with complex health needs. Hospital nurses, schools and community health care can play a valuable role in supporting the parents of children with complex health needs. It is important that parents are informed about their rights and receive a coordinator and interdisciplinary group to ensure that their needs are met with assistance and respite care. That maternal health was worse in this sample implies that health care professionals should pay more attention to reducing stress among these caregivers. © 2016 John Wiley & Sons Ltd.

Desorption of Hg(II) and Sb(V) on extracellular polymeric substances: effects of pH, EDTA, Ca(II) and temperature shocks.

PubMed

Zhang, Daoyong; Lee, Duu-Jong; Pan, Xiangliang

2013-01-01

Extracellular polymeric substances (EPS) existed ubiquitously in biological systems affect the mobility and availability of heavy metals in the environments. The adsorption-desorption behaviors of Hg(II) and Sb(V) on EPS were investigated. The sorption rates follow Sb(V) > Hg(II), and the desorption rates follow reverse order. Applications of ethylene diamine tetraacetic acid (EDTA), Ca(II) and pH shocks affect desorption rates and desorbed quantities of Hg(II) from EPS-Hg complex. Temperature shock minimally affects the desorption rate of Hg(II). Conversely, the EPS-Sb complex is stable subjected to EDTA, Ca(II), temperature or pH shocks. The excitation-emission matrix (EEM) fluorescence spectroscopy and fast-Fourier (FT-IR) analysis showed that Hg(II) and Sb(V) principally interacted with polysaccharides and protein-like compounds in the EPS, respectively. The EPS-Hg complex presents a time bomb that may release high levels of Hg(II) in short time period under environmental shocks. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Association between Motivation, Affect, and Self-regulated Learning When Solving Problems.

PubMed

Baars, Martine; Wijnia, Lisette; Paas, Fred

2017-01-01

Self-regulated learning (SRL) skills are essential for learning during school years, particularly in complex problem-solving domains, such as biology and math. Although a lot of studies have focused on the cognitive resources that are needed for learning to solve problems in a self-regulated way, affective and motivational resources have received much less research attention. The current study investigated the relation between affect (i.e., Positive Affect and Negative Affect Scale), motivation (i.e., autonomous and controlled motivation), mental effort, SRL skills, and problem-solving performance when learning to solve biology problems in a self-regulated online learning environment. In the learning phase, secondary education students studied video-modeling examples of how to solve hereditary problems, solved hereditary problems which they chose themselves from a set of problems with different complexity levels (i.e., five levels). In the posttest, students solved hereditary problems, self-assessed their performance, and chose a next problem from the set of problems but did not solve these problems. The results from this study showed that negative affect, inaccurate self-assessments during the posttest, and higher perceptions of mental effort during the posttest were negatively associated with problem-solving performance after learning in a self-regulated way.

The Effect of Syntactic Complexity on Fluency: Comparing Actives and Passives in L1 and L2 Speech

ERIC Educational Resources Information Center

Sadri Mirdamadi, Farhad; De Jong, Nivja H.

2015-01-01

This study investigates how syntactic complexity affects speaking performance in first (L1) and second language (L2) in terms of speaking fluency. Participants (30 Dutch native speakers with an average to advanced level of English) performed two speaking experiments, one in Dutch (L1) and one in English (L2). Syntactic complexity was…

Aquatic Humic Substances: Relationship Between Origin and Complexing Capacity.

PubMed

González-Guadarrama, María de Jesús; Armienta-Hernández, Ma Aurora; Rosa, André H

2018-05-01

Aiming to determine the relationship between source and complexing capacity, humic substances obtained from three sites (Sorocaba and Itapanhau Brasilian rivers, and Xochimilco Lake in Mexico) were studied. Copper, manganese, zinc and arsenic complexing capacity were determined for the three substances under various pH conditions. Results showed similar complexing capacity for the three elements depending on the chemistry of each one and on the physico-chemical conditions. Speciation diagrams showed that these conditions affect both, the humic substances, and the transition metals and arsenic.

Assessing chemical exposure and ecological impacts of environmental surface waters using cell culture-based metabolomic

EPA Science Inventory

Waste water treatment plants (WWTPs), as well as industrial and agricultural operations release complex mixtures of anthropogenic chemicals that negatively affect surface water quality. Previous studies have shown that exposure to such complex chemical mixtures can produce adver...

Deconstructing the Education-Industrial Complex in the Digital Age

ERIC Educational Resources Information Center

Loveless, Douglas, Ed.; Sullivan, Pamela, Ed.; Dredger, Katie, Ed.; Burns, Jim, Ed.

2017-01-01

Developments in the education field are affected by numerous, and often conflicting, social, cultural, and economic factors. With the increasing corporatization of education, teaching and learning paradigms are continuously altered. "Deconstructing the Education-Industrial Complex in the Digital Age" is an authoritative reference source…

Environmental Complexity and Central Nervous System Development and Function

ERIC Educational Resources Information Center

Lewis, Mark H.

2004-01-01

Environmental restriction or deprivation early in development can induce social, cognitive, affective, and motor abnormalities similar to those associated with autism. Conversely, rearing animals in larger, more complex environments results in enhanced brain structure and function, including increased brain weight, dendritic branching,…

Trauma-Focused CBT for Youth with Complex Trauma

ERIC Educational Resources Information Center

Cohen, Judith A.; Mannarino, Anthony P.; Kliethermes, Matthew; Murray, Laura A.

2012-01-01

Objectives: Many youth develop complex trauma, which includes regulation problems in the domains of affect, attachment, behavior, biology, cognition, and perception. Therapists often request strategies for using evidence-based treatments (EBTs) for this population. This article describes practical strategies for applying Trauma-Focused Cognitive…

αE-catenin regulates actin dynamics independently of cadherin-mediated cell–cell adhesion

PubMed Central

Benjamin, Jacqueline M.; Kwiatkowski, Adam V.; Yang, Changsong; Korobova, Farida; Pokutta, Sabine; Svitkina, Tatyana

2010-01-01

αE-catenin binds the cell–cell adhesion complex of E-cadherin and β-catenin (β-cat) and regulates filamentous actin (F-actin) dynamics. In vitro, binding of αE-catenin to the E-cadherin–β-cat complex lowers αE-catenin affinity for F-actin, and αE-catenin alone can bind F-actin and inhibit Arp2/3 complex–mediated actin polymerization. In cells, to test whether αE-catenin regulates actin dynamics independently of the cadherin complex, the cytosolic αE-catenin pool was sequestered to mitochondria without affecting overall levels of αE-catenin or the cadherin–catenin complex. Sequestering cytosolic αE-catenin to mitochondria alters lamellipodia architecture and increases membrane dynamics and cell migration without affecting cell–cell adhesion. In contrast, sequestration of cytosolic αE-catenin to the plasma membrane reduces membrane dynamics. These results demonstrate that the cytosolic pool of αE-catenin regulates actin dynamics independently of cell–cell adhesion. PMID:20404114

The Aegean/Cycladic and the Basin and Range Extensional Provinces - A Tectonic and Geochronologic Perspective

NASA Astrophysics Data System (ADS)

Stockli, D. F.

2017-12-01

The Aegean/Cycladic region (AC) and the Basin and Range Province (B&R) are two of the most famous Cenozoic extensional provinces and have greatly influenced our thinking about syn-convergent back-arc extension, core complex formation, syn-extensional magmatism, and kinematic transitions. They share numerous tectonic and structural similarities, such as a syn-convergent setting, previous contractional deformation, and core complex formation, but fundamental geological ambiguities remain, mainly centering around timing. The B&R affected a previously contractional belt (Sevier) and voluminous continental magmatic arc that created a pre-extensional orogenic highland. Extension was long-lived and complex, driven by both gravitational collapse and temporally distinct kinematic boundary condition changes. The B&R was also affected by massive, largely pre-extensional regional magmatic flare-ups that modified both the thermal and crustal composition. As the B&R occupies an elevated interior plateau, syn-extensional basin deposits are exclusively continental in character. In contrast, the AC is a classic marine back-arc extensional province that affected an active subduction margin with numerous accreted oceanic and continental ribbons, exhuming an early Cenozoic HP-LT subduction complex. Exhumation of the HP-LT complex, however, was accommodated both by vertical extrusion and crustal extension. Late Cenozoic extensional faulting was contemporaneous with S-ward sweeping arc magmatism and affected by little to no kinematic changes. As both the AC and B&R experienced contractional deformation during K-Cz subduction and J-K shortening, respectively, it is critical to differentiate between contractional and extensional structures and fabrics. The lack of temporal constraints hampers the reconstructions of pre-extensional structural anatomies and extensional strain magnitudes or even the attribution of structures to specific geodynamic settings. Novel methodologies in petrochronology, detrital geochronology, and high- and low-T thermochronometry allow us to elucidate pre-extensional crustal geometries, differentiate contractional from extensional fabrics, and understand the thermal and rheological evolution of these extensional provinces in a more holistic fashion.

Factors affecting nucleolytic efficiency of some ternary metal complexes with DNA binding and recognition domains. Crystal and molecular structure of Zn(phen)(edda).

PubMed

Seng, Hoi-Ling; Ong, Han-Kiat Alan; Rahman, Raja Noor Zaliha Raja Abd; Yamin, Bohari M; Tiekink, Edward R T; Tan, Kong Wai; Maah, Mohd Jamil; Caracelli, Ignez; Ng, Chew Hee

2008-11-01

The binding selectivity of the M(phen)(edda) (M=Cu, Co, Ni, Zn; phen=1,10-phenanthroline, edda=ethylenediaminediacetic acid) complexes towards ds(CG)(6), ds(AT)(6) and ds(CGCGAATTCGCG) B-form oligonucleotide duplexes were studied by CD spectroscopy and molecular modeling. The binding mode is intercalation and there is selectivity towards AT-sequence and stacking preference for A/A parallel or diagonal adjacent base steps in their intercalation. The nucleolytic properties of these complexes were investigated and the factors affecting the extent of cleavage were determined to be: concentration of complex, the nature of metal(II) ion, type of buffer, pH of buffer, incubation time, incubation temperature, and the presence of hydrogen peroxide or ascorbic acid as exogenous reagents. The fluorescence property of these complexes and its origin were also investigated. The crystal structure of the Zn(phen)(edda) complex is reported in which the zinc atom displays a distorted trans-N(4)O(2) octahedral geometry; the crystal packing features double layers of complex molecules held together by extensive hydrogen bonding that inter-digitate with adjacent double layers via pi...pi interactions between 1,10-phenanthroline residues. The structure is compared with that of the recently described copper(II) analogue and, with the latter, included in molecular modeling.

Enhancing genomic prediction with genome-wide association studies in multiparental maize populations

USDA-ARS?s Scientific Manuscript database

Genome-wide association mapping using dense marker sets has identified some nucleotide variants affecting complex traits which have been validated with fine-mapping and functional analysis. Many sequence variants associated with complex traits in maize have small effects and low repeatability, howev...

School Phobia: Understanding a Complex Behavioural Response

ERIC Educational Resources Information Center

Chitiyo, Morgan; Wheeler, John J.

2006-01-01

School phobia affects about 5% of the school-age population. If left untreated, school phobia can have devastating long-term consequences in children challenged by this condition. Various treatment approaches have been used to explore this complex behavioural response, major among them being the psychoanalytic, psychodynamic, pharmacological and…

Chemical and non-chemical stressors affecting childhood obesity: a systematic scoping review

EPA Science Inventory

Childhood obesity in the United States has doubled over the last three decades and currently affects 17% of children and adolescents. While much research has focused on individual behaviors impacting obesity, little research has emphasized the complex interactions of numerous che...

Tuberous sclerosis complex surveillance and management: recommendations of the 2012 International Tuberous Sclerosis Complex Consensus Conference.

PubMed

Krueger, Darcy A; Northrup, Hope

2013-10-01

Tuberous sclerosis complex is a genetic disorder affecting every organ system, but disease manifestations vary significantly among affected individuals. The diverse and varied presentations and progression can be life-threatening with significant impact on cost and quality of life. Current surveillance and management practices are highly variable among region and country, reflective of the fact that last consensus recommendations occurred in 1998 and an updated, comprehensive standard is lacking that incorporates the latest scientific evidence and current best clinical practices. The 2012 International Tuberous Sclerosis Complex Consensus Group, comprising 79 specialists from 14 countries, was organized into 12 separate subcommittees, each led by a clinician with advanced expertise in tuberous sclerosis complex and the relevant medical subspecialty. Each subcommittee focused on a specific disease area with important clinical management implications and was charged with formulating key clinical questions to address within its focus area, reviewing relevant literature, evaluating the strength of data, and providing a recommendation accordingly. The updated consensus recommendations for clinical surveillance and management in tuberous sclerosis complex are summarized here. The recommendations are relevant to the entire lifespan of the patient, from infancy to adulthood, including both individuals where the diagnosis is newly made as well as individuals where the diagnosis already is established. The 2012 International Tuberous Sclerosis Complex Consensus Recommendations provide an evidence-based, standardized approach for optimal clinical care provided for individuals with tuberous sclerosis complex. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

Growth mechanisms of MgO nanocrystals via a sol-gel synthesis using different complexing agents

PubMed Central

2014-01-01

In the preparation of nanostructured materials, it is important to optimize synthesis parameters in order to obtain the desired material. This work investigates the role of complexing agents, oxalic acid and tartaric acid, in the production of MgO nanocrystals. Results from simultaneous thermogravimetric analysis (STA) show that the two different synthesis routes yield precursors with different thermal profiles. It is found that the thermal profiles of the precursors can reveal the effects of crystal growth during thermal annealing. X-ray diffraction confirms that the final products are pure, single phase and of cubic shape. It is also found that complexing agents can affect the rate of crystal growth. The structures of the oxalic acid and tartaric acid as well as the complexation sites play very important roles in the formation of the nanocrystals. The complexing agents influence the rate of growth which affects the final crystallite size of the materials. Surprisingly, it is also found that oxalic acid and tartaric acid act as surfactants inhibiting crystal growth even at a high temperature of 950°C and a long annealing time of 36 h. The crystallite formation routes are proposed to be via linear and branched polymer networks due to the different structures of the complexing agents. PMID:24650322

Vaccine-preventable disease and the under-utilization of immunizations in complex humanitarian emergencies.

PubMed

Close, Ryan M; Pearson, Catherine; Cohn, Jennifer

2016-09-07

Complex humanitarian emergencies affect 40-60 million people annually and are a growing public health concern worldwide. Despite efforts to provide medical and public health services to populations affected by complex emergencies, significant morbidity and mortality persist. Measles is a major communicable disease threat, but through vaccination of broader target age groups beyond the traditional immunization schedule, measles-related mortality has been significantly reduced during crises. Yet, a limited number of vaccine-preventable diseases continue to contribute disproportionately to morbidity and mortality in complex emergencies. The literature suggests that Streptococcus pneumoniae, Rotavirus, and Haemophilus influenzae type-b should be key targets for vaccination programs. Because of the significant contribution of these three pathogens to complex humanitarian emergencies in low and middle-income countries regardless of disaster type, geography, or population, their vaccines should be considered essential components of the standard emergency response effort. We discuss the barriers to vaccine distribution and provide evidence for strategies to improve distribution, including expanded target age-range and reduced dose schedules. Our review includes specific recommendations for the expanded use of these three vaccines in complex emergencies in low and middle-income countries as a way to guide future policy discussions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of additives on chemoselectivity and diastereoselectivity in the catalytic epoxidation of chiral allylic alcohols with hydrogen peroxide and binuclear manganese complexes.

PubMed

Kilic, Hamdullah; Adam, Waldemar; Alsters, Paul L

2009-02-06

The catalytic oxidations of chiral allylic alcohols 2 by manganese complexes of the cyclic triamine 1,4,7-trimethyl-1,4,7-triazacyclononane (tmtacn) 1 and hydrogen peroxide as oxygen donor in the presence of co-catalyst are investigated to understand the factors that affect the catalyst selectivity. Chemoselectivity and diastereoselectivity of catalyst 1 are significantly affected by the structure of the allylic alcohol and the nature and amount of co-catalyst. More pronounced is the influence of the amount of added molar equivalents of H(2)O(2) (20-110 mol % with respect to the substrate). Our present results reflect the complex redox chemistry of the Mn catalyst 1/H(2)O(2)/co-catalyst system in the early phase of the alkene oxidation.

Management intensity and vegetation complexity affect web-building spiders and their prey.

PubMed

Diehl, Eva; Mader, Viktoria L; Wolters, Volkmar; Birkhofer, Klaus

2013-10-01

Agricultural management and vegetation complexity affect arthropod diversity and may alter trophic interactions between predators and their prey. Web-building spiders are abundant generalist predators and important natural enemies of pests. We analyzed how management intensity (tillage, cutting of the vegetation, grazing by cattle, and synthetic and organic inputs) and vegetation complexity (plant species richness, vegetation height, coverage, and density) affect rarefied richness and composition of web-building spiders and their prey with respect to prey availability and aphid predation in 12 habitats, ranging from an uncut fallow to a conventionally managed maize field. Spiders and prey from webs were collected manually and the potential prey were quantified using sticky traps. The species richness of web-building spiders and the order richness of prey increased with plant diversity and vegetation coverage. Prey order richness was lower at tilled compared to no-till sites. Hemipterans (primarily aphids) were overrepresented, while dipterans, hymenopterans, and thysanopterans were underrepresented in webs compared to sticky traps. The per spider capture efficiency for aphids was higher at tilled than at no-till sites and decreased with vegetation complexity. After accounting for local densities, 1.8 times more aphids were captured at uncut compared to cut sites. Our results emphasize the functional role of web-building spiders in aphid predation, but suggest negative effects of cutting or harvesting. We conclude that reduced management intensity and increased vegetation complexity help to conserve local invertebrate diversity, and that web-building spiders at sites under low management intensity (e.g., semi-natural habitats) contribute to aphid suppression at the landscape scale.

Loss of Mitochondrial Ndufs4 in Striatal Medium Spiny Neurons Mediates Progressive Motor Impairment in a Mouse Model of Leigh Syndrome.

PubMed

Chen, Byron; Hui, Jessica; Montgomery, Kelsey S; Gella, Alejandro; Bolea, Irene; Sanz, Elisenda; Palmiter, Richard D; Quintana, Albert

2017-01-01

Inability of mitochondria to generate energy leads to severe and often fatal myoencephalopathies. Among these, Leigh syndrome (LS) is one of the most common childhood mitochondrial diseases; it is characterized by hypotonia, failure to thrive, respiratory insufficiency and progressive mental and motor dysfunction, leading to early death. Basal ganglia nuclei, including the striatum, are affected in LS patients. However, neither the identity of the affected cell types in the striatum nor their contribution to the disease has been established. Here, we used a mouse model of LS lacking Ndufs4 , a mitochondrial complex I subunit, to confirm that loss of complex I, but not complex II, alters respiration in the striatum. To assess the role of striatal dysfunction in the pathology, we selectively inactivated Ndufs4 in the striatal medium spiny neurons (MSNs), which account for over 95% of striatal neurons. Our results show that lack of Ndufs4 in MSNs causes a non-fatal progressive motor impairment without affecting the cognitive function of mice. Furthermore, no inflammatory responses or neuronal loss were observed up to 6 months of age. Hence, complex I deficiency in MSNs contributes to the motor deficits observed in LS, but not to the neural degeneration, suggesting that other neuronal populations drive the plethora of clinical signs in LS.

Effects of Plutonium on Soil Microorganisms

PubMed Central

Wildung, Raymond E.; Garland, Thomas R.

1982-01-01

As a first phase in an investigation of the role of the soil microflora in Pu complex formation and solubilization in soil, the effects of Pu concentration, form, and specific activity on microbial types, colony-forming units, and CO2 evolution rate were determined in soils amended with C and N sources to optimize microbial activity. The effects of Pu differed with organism type and incubation time. After 30 days of incubation, aerobic sporeforming and anaerobic bacteria were significantly affected by soil Pu levels as low as 1 μg/g when Pu was added as the hydrolyzable 239Pu(NO3)4 (solubility, <0.1% in soil). Other classes of organisms, except the fungi, were significantly affected at soil Pu levels of 10 μg/g. Fungi were affected only at soil Pu levels of 180 μg/g. Soil CO2 evolution rate and total accumulated CO2 were affected by Pu only at the 180 μg/g level. Because of the possible role of resistant organisms in complex formation, the mechanisms of effects of Pu on the soil fungi were further evaluated. The effect of Pu on soil fungal colony-forming units was a function of Pu solubility in soil and Pu specific activity. When Pu was added in a soluble, complexed form [238Pu2(diethylenetriaminepentaacetate)3], effects occurred at Pu levels of 1 μg/g and persisted for at least 95 days. Toxicity was due primarily to radiation effects rather than to chemical effects, suggesting that, at least in the case of the fungi, formation of Pu complexes would result primarily from ligands associated with normal (in contrast to chemically-induced) biochemical pathways. PMID:16345947

Memory ability of children with complex communication needs.

PubMed

Larsson, Maria; Sandberg, Annika Dahlgren

2008-01-01

Phonological memory is central to language and reading and writing skills. Many children with complex communication needs (CCN) experience problems with reading and writing acquisition. The reason could be because of the absence of articulatory ability, which might have a negative affect on phonological memory. Phonological and visuo-spatial short-term memory and working memory were tested in 15 children with CCN, aged 5 - 12 years, and compared to children with natural speech matched for gender, and mental and linguistic age. Results indicated weaker phonological STM and visuo-spatial STM and WM in children with CCN. The lack of articulatory ability could be assumed to affect subvocal rehearsal and, therefore, phonological memory which, in turn, may affect reading and writing acquisition. Weak visuo-spatial memory could also complicate the use of Bliss symbols and other types of augmentative and alternative communication.

Towards Tunable Consensus Clustering for Studying Functional Brain Connectivity During Affective Processing.

PubMed

Liu, Chao; Abu-Jamous, Basel; Brattico, Elvira; Nandi, Asoke K

2017-03-01

In the past decades, neuroimaging of humans has gained a position of status within neuroscience, and data-driven approaches and functional connectivity analyses of functional magnetic resonance imaging (fMRI) data are increasingly favored to depict the complex architecture of human brains. However, the reliability of these findings is jeopardized by too many analysis methods and sometimes too few samples used, which leads to discord among researchers. We propose a tunable consensus clustering paradigm that aims at overcoming the clustering methods selection problem as well as reliability issues in neuroimaging by means of first applying several analysis methods (three in this study) on multiple datasets and then integrating the clustering results. To validate the method, we applied it to a complex fMRI experiment involving affective processing of hundreds of music clips. We found that brain structures related to visual, reward, and auditory processing have intrinsic spatial patterns of coherent neuroactivity during affective processing. The comparisons between the results obtained from our method and those from each individual clustering algorithm demonstrate that our paradigm has notable advantages over traditional single clustering algorithms in being able to evidence robust connectivity patterns even with complex neuroimaging data involving a variety of stimuli and affective evaluations of them. The consensus clustering method is implemented in the R package "UNCLES" available on http://cran.r-project.org/web/packages/UNCLES/index.html .

Emotion and Transformational Leadership in Graduate Faculty-Student Relationships

ERIC Educational Resources Information Center

Williams, Jason R.

2009-01-01

The purpose of this study was to investigate the relationships among transformational leadership, emotional complexity, and positive/negative emotions of leaders and followers. How leader openness, emotional complexity, gender, and trait affect may influence the extent to which leaders use various types of leadership and mentoring, and how all of…

Global warming and stress complexes in forests of western North America

Treesearch

Donald McKenzie; David L. Peterson; Jeremy J. Littell

2009-01-01

A warmer climate in western North America will likely affect forests directly through soil moisture stress and indirectly through increased extent and severity of disturbances. We propose that stress complexes, combinations of biotic and abiotic stresses, compromise the vigor and ultimate sustainability of forest ecosystems. Across...

Comprehension of Complex Discourse in Different Stages of Huntington's Disease

ERIC Educational Resources Information Center

Saldert, Charlotta; Fors, Angelika; Stroberg, Sofia; Hartelius, Lena

2010-01-01

Background: Huntington's disease not only affects motor speech control, but also may have an impact on the ability to produce and understand language in communication. Aims: The ability to comprehend basic and complex discourse was investigated in three different stages of Huntington's disease. Methods & Procedures: In this experimental group…

A Complexity Approach to Evaluating National Scientific Systems through International Scientific Collaborations

ERIC Educational Resources Information Center

Zelnio, Ryan J.

2013-01-01

This dissertation seeks to contribute to a fuller understanding of how international scientific collaboration has affected national scientific systems. It does this by developing three methodological approaches grounded in social complexity theory and applying them to the evaluation of national scientific systems. The first methodology identifies…

Say again? How complexity and format of air traffic control instructions affect pilot recall

DOT National Transportation Integrated Search

1999-01-01

This study compared the recall of ATC information presented in cither grouped or sequential format : in a part-task simulation. It also tested the effect of complexity of ATC clearances on recall, that is, : how many pieces of information a single tr...

Complexity Science and the Dynamics of Climate and Communication: Reducing Nursing Home Turnover

ERIC Educational Resources Information Center

Anderson, Ruth A.; Corazzini, Kirsten N.; McDaniel, Reuben R., Jr.

2004-01-01

Purpose: Turnover in nursing homes is a widespread problem adversely affecting care quality. Using complexity theory, we tested the effect of administrative climate, communication patterns, and the interaction between the two on turnover, controlling for facility context. Design and Methods: Perceptions of administrative climate and communication…

Rhythms of Mental Performance

ERIC Educational Resources Information Center

Valdez, Pablo; Reilly, Thomas; Waterhouse, Jim

2008-01-01

Cognitive performance is affected by an individual's characteristics and the environment, as well as by the nature of the task and the amount of practice at it. Mental performance tests range in complexity and include subjective estimates of mood, simple objective tests (reaction time), and measures of complex performance that require decisions to…

Utility of computer simulations in landscape genetics

Treesearch

Bryan K. Epperson; Brad H. McRae; Kim Scribner; Samuel A. Cushman; Michael S. Rosenberg; Marie-Josee Fortin; Patrick M. A. James; Melanie Murphy; Stephanie Manel; Pierre Legendre; Mark R. T. Dale

2010-01-01

Population genetics theory is primarily based on mathematical models in which spatial complexity and temporal variability are largely ignored. In contrast, the field of landscape genetics expressly focuses on how population genetic processes are affected by complex spatial and temporal environmental heterogeneity. It is spatially explicit and relates patterns to...

Closed genomes of seven histophilus somni isolates from beef calves with bovine respiratory disease complex

USDA-ARS?s Scientific Manuscript database

Histophilus somni is a fastidious gram-negative opportunistic pathogenic Pasteurellacea that affects multiple organ systems and is one of the principle bacterial species contributing to bovine respiratory disease complex (BRDC) in feed yard cattle. Here we present seven closed genomes isolated from...

Closed genomes and phenotypes of seven Histophilus somni isolates from beef calves with bovine respiratory disease complex

USDA-ARS?s Scientific Manuscript database

Background: Histophilus somni is a fastidious gram-negative opportunistic pathogenic Pasteurellacea that affects multiple organ systems and is one of three principle bacterial species contributing to bovine respiratory disease complex (BRDC) in North American feed yard cattle. BRDC outbreaks accoun...

CONSTANTS FOR MERCURY BINDING BY DISSOLVED ORGANIC MATTER ISOLATES FROM THE FLORIDA EVERGLADES. (R827653)

EPA Science Inventory

Dissolved organic matter (DOM) has been implicated as an important complexing agent for Hg that can affect its mobility and bioavailability in aquatic ecosystems. However, binding constants for natural Hg-DOM complexes are not well known. We employed a competitive ligand appro...

Nutritional Factors Affecting Adult Neurogenesis and Cognitive Function

USDA-ARS?s Scientific Manuscript database

Adult neurogenesis, a complex process by which stem cells in the hippocampal brain region differentiate and proliferate into new neurons and other resident brain cells, is known to be affected by many intrinsic and extrinsic factors, including diet. Neurogenesis plays a critical role in neural plas...

The importance of contextual, relational and cognitive factors for novice nurses' emotional state and affective commitment to the profession. A multilevel study.

PubMed

Hoeve, Yvonne Ten; Brouwer, Jasperina; Roodbol, Petrie F; Kunnen, Saskia

2018-05-13

This study explored the effects of contextual, relational and cognitive factors derived from novice nurses' work experiences on emotions and affective commitment to the profession. With an increasing demand for well-trained nurses, it is imperative to investigate which work-related factors most affect their commitment to develop effective strategies to improve work conditions, work satisfaction and emotional attachment. A repeated-measures within subjects design. From September 2013 - September 2014 eighteen novice nurses described work-related experiences in unstructured diaries and scored their emotional state and affective commitment on a scale. The themes that emerged from the 18 diaries (with 580 diary entries) were quantified as contextual, relational and cognitive factors. Contextual factors refer to complexity of care and existential events; relational factors to experiences with patients, support from colleagues, supervisors and physicians; cognitive factors to nurses' perceived competence. The first multilevel regression analysis, based on the 18 diaries with 580 entries, showed that complexity of care, lack of support and lack of competence were negatively related to novice nurses' affective commitment, whereas received support was positively related. The next multilevel regression analyses showed that all contextual, relational and cognitive factors were either related to negative or positive emotions. To retain novice nurses in the profession, it is important to provide support and feedback. This enables novice nurses to deal with the complexity of care and feelings of incompetence and to develop a professional commitment. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Pitch discrimination learning: specificity for pitch and harmonic resolvability, and electrophysiological correlates.

PubMed

Carcagno, Samuele; Plack, Christopher J

2011-08-01

Multiple-hour training on a pitch discrimination task dramatically decreases the threshold for detecting a pitch difference between two harmonic complexes. Here, we investigated the specificity of this perceptual learning with respect to the pitch and the resolvability of the trained harmonic complex, as well as its cortical electrophysiological correlates. We trained 24 participants for 12 h on a pitch discrimination task using one of four different harmonic complexes. The complexes differed in pitch and/or spectral resolvability of their components by the cochlea, but were filtered into the same spectral region. Cortical-evoked potentials and a behavioral measure of pitch discrimination were assessed before and after training for all the four complexes. The change in these measures was compared to that of two control groups: one trained on a level discrimination task and one without any training. The behavioral results showed that learning was partly specific to both pitch and resolvability. Training with a resolved-harmonic complex improved pitch discrimination for resolved complexes more than training with an unresolved complex. However, we did not find evidence that training with an unresolved complex leads to specific learning for unresolved complexes. Training affected the P2 component of the cortical-evoked potentials, as well as a later component (250-400 ms). No significant changes were found on the mismatch negativity (MMN) component, although a separate experiment showed that this measure was sensitive to pitch changes equivalent to the pitch discriminability changes induced by training. This result suggests that pitch discrimination training affects processes not measured by the MMN, for example, processes higher in level or parallel to those involved in MMN generation.

Visual search and segregation as a function of display complexity.

PubMed

Scharroo, J; Stalmeier, P F; Boselie, F

1994-01-01

Complexity is proposed as an important psychological factor in search and segregation tasks. Displays were presented with target and nontarget areas that were each built up of one type of randomly rotated micropatterns. We manipulated experimentally (a) the complexity of the target elements, as measured by Garner's (1970) invariance criterion; (b) the complexity of the target region; (c) the complexity of the nontargets; and (d) the number of elements within a target region. The main result is that detectability increases when the within-region complexity of the target and the nontarget regions decreases. Furthermore, interactions between the target and nontarget areas affect detectability too: We found that search asymmetry is produced by the asymmetrical effect of complexity when target and nontarget areas are interchanged.

Channelopathies from Mutations in the Cardiac Sodium Channel Protein Complex

PubMed Central

Adsit, Graham S.; Vaidyanathan, Ravi; Galler, Carla M.; Kyle, John W.; Makielski, Jonathan C.

2013-01-01

The cardiac sodium current underlies excitability in heart, and inherited abnormalities of the proteins regulating and conducting this current cause inherited arrhythmia syndromes. This review focuses on inherited mutations in non-pore forming proteins of sodium channel complexes that cause cardiac arrhythmia, and the deduced mechanisms by which they affect function and dysfunction of the cardiac sodium current. Defining the structure and function of these complexes and how they are regulated will contribute to understanding the possible roles for this complex in normal and abnormal physiology and homeostasis. PMID:23557754

The Association between Motivation, Affect, and Self-regulated Learning When Solving Problems

PubMed Central

Baars, Martine; Wijnia, Lisette; Paas, Fred

2017-01-01

Self-regulated learning (SRL) skills are essential for learning during school years, particularly in complex problem-solving domains, such as biology and math. Although a lot of studies have focused on the cognitive resources that are needed for learning to solve problems in a self-regulated way, affective and motivational resources have received much less research attention. The current study investigated the relation between affect (i.e., Positive Affect and Negative Affect Scale), motivation (i.e., autonomous and controlled motivation), mental effort, SRL skills, and problem-solving performance when learning to solve biology problems in a self-regulated online learning environment. In the learning phase, secondary education students studied video-modeling examples of how to solve hereditary problems, solved hereditary problems which they chose themselves from a set of problems with different complexity levels (i.e., five levels). In the posttest, students solved hereditary problems, self-assessed their performance, and chose a next problem from the set of problems but did not solve these problems. The results from this study showed that negative affect, inaccurate self-assessments during the posttest, and higher perceptions of mental effort during the posttest were negatively associated with problem-solving performance after learning in a self-regulated way. PMID:28848467

Globalization in the Face of Standardization: Implications for Teacher Education

ERIC Educational Resources Information Center

Delgado, Rocio; Norman, Patricia

2008-01-01

As globalization affects political and economic systems, cultures, and the environment, it affects the educational needs of a globalized workforce. In this complex, fast-evolving knowledge economy, workers must possess analytic skills, creativity, flexibility, and innovation. They need oral and written communication skills and the disposition to…

Exploring whether and how ants affect reproductive fitness in Senna mexicana var. chapmanii

USDA-ARS?s Scientific Manuscript database

Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and ants. Ant-plant mutualisms are keystone associations, occurring within a complex web of biotic interactions. As such, these interactions may affect plant fitness in a number of ways, both positive and negative. In S...

Leukogram abnormalities in gnotobiotic pigs infected with porcine circovirus type 2

USDA-ARS?s Scientific Manuscript database

Porcine circovirus type 2 (PCV2) is a single-stranded circular DNA virus that is the causative agent of porcine circovirus associated disease (PCVAD), a disease complex affecting swine around the world. Although this virus is believed to negatively affect the host's immune system, the mechanism by ...

Investigating the Experiential Impact of Sensory Affect in Contemporary Communication Design Studio Education

ERIC Educational Resources Information Center

Marshalsey, Lorraine

2015-01-01

The studio is the primary site for learning in specialist Communication Design education worldwide. Differing higher education institutions, including art schools and university campuses, have developed a varied range of studio environments. These diverse learning spaces inherently create a complex fabric of affects. In addition, Communication…

Factors, Correlates, Emotional Barriers Affecting Career Decisions of College Students.

ERIC Educational Resources Information Center

O'Neil, James M.; And Others

The correlates of career choice and the problem areas affecting career decisions are important to counseling psychologists. They are important to understanding the complexities of vocational behavior, facilitating differential treatment in counseling, and developing preventive career programs for men, women, and special groups. The effects of the…

Tourette Syndrome: Information for School Nurses

ERIC Educational Resources Information Center

Golder, Tracy

2010-01-01

Tourette syndrome (TS) is a neurobehavioral disorder that consists of simple and complex tics. This disorder can significantly affect a child's self-esteem and academic success. Although some believe that only adults are affected, this disorder occurs most frequently in early childhood and symptoms decrease with age. Diagnosis of this disorder can…

Dynamics of Affective States during Complex Learning

ERIC Educational Resources Information Center

D'Mello, Sidney; Graesser, Art

2012-01-01

We propose a model to explain the dynamics of affective states that emerge during deep learning activities. The model predicts that learners in a state of engagement/flow will experience cognitive disequilibrium and confusion when they face contradictions, incongruities, anomalies, obstacles to goals, and other impasses. Learners revert into the…

Evaluation of factors affecting nitrous oxide emission and N transformation in a sandy loam soil

USDA-ARS?s Scientific Manuscript database

A better understanding of the complex factors affecting nitrous oxide (N2O) emission and potential mitigation practices will assist in developing strategies to improve the sustainability of agricultural production systems. Using surface soil collected from a pomegranate orchard, a series of laborato...

Treatment of VGKC complex antibody-associated limbic encephalitis: a systematic review.

PubMed

Radja, Guirindhra Koumar; Cavanna, Andrea Eugenio

2013-01-01

Limbic encephalitis is an autoimmune neuropsychiatric condition characterized by subacute cognitive symptoms, seizures, and affective changes. Although limbic encephalitis is usually caused by an immune reaction secondary to neoplasms, different types of potentially treatable non-paraneoplastic limbic encephalitis (nPLE) have recently been described. In particular, published studies have reported variable responses to immunosuppressive therapy in Voltage-Gated Potassium Channel (VGKC) complex antibody-associated nPLE. This systematic literature review found that the most significant improvements were reported by patients presenting with affective symptoms and consistent neuroradiological changes. In these patients, improved clinical outcomes correlated with the largest decreases in antibody titers.

Affective facilitation of early visual cortex during rapid picture presentation at 6 and 15 Hz

PubMed Central

Bekhtereva, Valeria

2015-01-01

The steady-state visual evoked potential (SSVEP), a neurophysiological marker of attentional resource allocation with its generators in early visual cortex, exhibits enhanced amplitude for emotional compared to neutral complex pictures. Emotional cue extraction for complex images is linked to the N1-EPN complex with a peak latency of ∼140–160 ms. We tested whether neural facilitation in early visual cortex with affective pictures requires emotional cue extraction of individual images, even when a stream of images of the same valence category is presented. Images were shown at either 6 Hz (167 ms, allowing for extraction) or 15 Hz (67 ms per image, causing disruption of processing by the following image). Results showed SSVEP amplitude enhancement for emotional compared to neutral images at a presentation rate of 6 Hz but no differences at 15 Hz. This was not due to featural differences between the two valence categories. Results strongly suggest that individual images need to be displayed for sufficient time allowing for emotional cue extraction to drive affective neural modulation in early visual cortex. PMID:25971598

The interplay between habitat structure and chemical contaminants on biotic responses of benthic organisms

PubMed Central

Matias, Miguel G.; Coleman, Ross A.

2016-01-01

Habitat structure influences the diversity and distribution of organisms, potentially affecting their response to disturbances by either affecting their ‘susceptibility’ or through the provision of resources that can mitigate impacts of disturbances. Chemical disturbances due to contamination are associated with decreases in diversity and functioning of systems and are also likely to increase due to coastal urbanisation. Understanding how habitat structure interacts with contaminants is essential to predict and therefore manage such effects, minimising their consequences to marine systems. Here, we manipulated two structurally different habitats and exposed them to different types of contaminants. The effects of contamination and habitat structure interacted, affecting species richness. More complex experimental habitats were colonized by a greater diversity of organisms than the less complex habitats. These differences disappeared, however, when habitats were exposed to contaminants, suggesting that contaminants can override effects of habitats structure at small spatial scales. These results provide insight into the complex ways that habitat structure and contamination interact and the need to incorporate evidence of biotic responses from individual disturbances to multiple stressors. Such effects need to be taken into account when designing and planning management and conservation strategies to natural systems. PMID:27168991

The human immunodeficiency virus type 1 long terminal repeat specifies two different transcription complexes, only one of which is regulated by Tat.

PubMed Central

Lu, X; Welsh, T M; Peterlin, B M

1993-01-01

The human immunodeficiency virus type 1 long terminal repeat sets up two different transcription complexes, which have been called processive and nonprocessive complexes. By mutating and substituting cis-acting sequences, we mapped elements of the human immunodeficiency virus long terminal repeat that are responsible for creating each transcription complex. Whereas processive complexes are efficiently assembled by upstream promoter elements in the absence of the TATA box, nonprocessive complexes absolutely require the TATA box. Moreover, the TATA box alone can set up these nonprocessive complexes, and nonprocessive but not processive complexes are trans activated by Tat. Finally, a strong DNA-binding site between the TATA box and trans-activation-responsive region interferes with either the assembly or movement of these nonprocessive complexes and diminishes the effects of Tat. Thus, Tat affects a critical step in the formation of elongation-competent transcription complexes. Images PMID:8445708

Influence of chemical disorder on energy dissipation and defect evolution in concentrated solid solution alloys

PubMed Central

Zhang, Yanwen; Stocks, G. Malcolm; Jin, Ke; Lu, Chenyang; Bei, Hongbin; Sales, Brian C.; Wang, Lumin; Béland, Laurent K.; Stoller, Roger E.; Samolyuk, German D.; Caro, Magdalena; Caro, Alfredo; Weber, William J.

2015-01-01

A grand challenge in materials research is to understand complex electronic correlation and non-equilibrium atomic interactions, and how such intrinsic properties and dynamic processes affect energy transfer and defect evolution in irradiated materials. Here we report that chemical disorder, with an increasing number of principal elements and/or altered concentrations of specific elements, in single-phase concentrated solid solution alloys can lead to substantial reduction in electron mean free path and orders of magnitude decrease in electrical and thermal conductivity. The subsequently slow energy dissipation affects defect dynamics at the early stages, and consequentially may result in less deleterious defects. Suppressed damage accumulation with increasing chemical disorder from pure nickel to binary and to more complex quaternary solid solutions is observed. Understanding and controlling energy dissipation and defect dynamics by altering alloy complexity may pave the way for new design principles of radiation-tolerant structural alloys for energy applications. PMID:26507943

Does Human Migration Affect International Trade? A Complex-Network Perspective

PubMed Central

Fagiolo, Giorgio; Mastrorillo, Marina

2014-01-01

This paper explores the relationships between international human migration and merchandise trade using a complex-network approach. We firstly compare the topological structure of worldwide networks of human migration and bilateral trade over the period 1960–2000. Next, we ask whether pairs of countries that are more central in the migration network trade more. We show that: (i) the networks of international migration and trade are strongly correlated, and such correlation can be mostly explained by country economic/demographic size and geographical distance; (ii) centrality in the international-migration network boosts bilateral trade; (iii) intensive forms of country centrality are more trade enhancing than their extensive counterparts. Our findings suggest that bilateral trade between any two countries is not only affected by the presence of migrants from either countries, but also by their relative embeddedness in the complex web of corridors making up the network of international human migration. PMID:24828376

Stage structure alters how complexity affects stability of ecological networks

USGS Publications Warehouse

Rudolf, V.H.W.; Lafferty, Kevin D.

2011-01-01

Resolving how complexity affects stability of natural communities is of key importance for predicting the consequences of biodiversity loss. Central to previous stability analysis has been the assumption that the resources of a consumer are substitutable. However, during their development, most species change diets; for instance, adults often use different resources than larvae or juveniles. Here, we show that such ontogenetic niche shifts are common in real ecological networks and that consideration of these shifts can alter which species are predicted to be at risk of extinction. Furthermore, niche shifts reduce and can even reverse the otherwise stabilizing effect of complexity. This pattern arises because species with several specialized life stages appear to be generalists at the species level but act as sequential specialists that are hypersensitive to resource loss. These results suggest that natural communities are more vulnerable to biodiversity loss than indicated by previous analyses.

Virality Prediction and Community Structure in Social Networks

NASA Astrophysics Data System (ADS)

Weng, Lilian; Menczer, Filippo; Ahn, Yong-Yeol

2013-08-01

How does network structure affect diffusion? Recent studies suggest that the answer depends on the type of contagion. Complex contagions, unlike infectious diseases (simple contagions), are affected by social reinforcement and homophily. Hence, the spread within highly clustered communities is enhanced, while diffusion across communities is hampered. A common hypothesis is that memes and behaviors are complex contagions. We show that, while most memes indeed spread like complex contagions, a few viral memes spread across many communities, like diseases. We demonstrate that the future popularity of a meme can be predicted by quantifying its early spreading pattern in terms of community concentration. The more communities a meme permeates, the more viral it is. We present a practical method to translate data about community structure into predictive knowledge about what information will spread widely. This connection contributes to our understanding in computational social science, social media analytics, and marketing applications.

Virality Prediction and Community Structure in Social Networks

PubMed Central

Weng, Lilian; Menczer, Filippo; Ahn, Yong-Yeol

2013-01-01

How does network structure affect diffusion? Recent studies suggest that the answer depends on the type of contagion. Complex contagions, unlike infectious diseases (simple contagions), are affected by social reinforcement and homophily. Hence, the spread within highly clustered communities is enhanced, while diffusion across communities is hampered. A common hypothesis is that memes and behaviors are complex contagions. We show that, while most memes indeed spread like complex contagions, a few viral memes spread across many communities, like diseases. We demonstrate that the future popularity of a meme can be predicted by quantifying its early spreading pattern in terms of community concentration. The more communities a meme permeates, the more viral it is. We present a practical method to translate data about community structure into predictive knowledge about what information will spread widely. This connection contributes to our understanding in computational social science, social media analytics, and marketing applications. PMID:23982106

Virality prediction and community structure in social networks.

PubMed

Weng, Lilian; Menczer, Filippo; Ahn, Yong-Yeol

2013-01-01

How does network structure affect diffusion? Recent studies suggest that the answer depends on the type of contagion. Complex contagions, unlike infectious diseases (simple contagions), are affected by social reinforcement and homophily. Hence, the spread within highly clustered communities is enhanced, while diffusion across communities is hampered. A common hypothesis is that memes and behaviors are complex contagions. We show that, while most memes indeed spread like complex contagions, a few viral memes spread across many communities, like diseases. We demonstrate that the future popularity of a meme can be predicted by quantifying its early spreading pattern in terms of community concentration. The more communities a meme permeates, the more viral it is. We present a practical method to translate data about community structure into predictive knowledge about what information will spread widely. This connection contributes to our understanding in computational social science, social media analytics, and marketing applications.

Ideal affect in daily life: implications for affective experience, health, and social behavior.

PubMed

Tsai, Jeanne L

2017-10-01

Over the last decade, researchers have increasingly demonstrated that ideal affect-the affective states that people value and ideally want to feel-shapes different aspects of daily life. Here I briefly review Affect Valuation Theory (AVT), which integrates ideal affect into existing models of affect and emotion by identifying the causes and consequences of variation in ideal affect. I then describe recent research that applies AVT to the valuation of negative states as well as more complex states, examines how ideal affect shapes momentary affective experience, suggests that ideal affect has both direct and indirect effects on health, and illustrates that people's ideal affect shapes how they judge and respond to others. Finally, I discuss the implications of cultural and individual differences in ideal affect for clinical, educational, work, and leisure settings. Copyright © 2017 Elsevier Ltd. All rights reserved.

Visual Complexity Attenuates Emotional Processing in Psychopathy: Implications for Fear-Potentiated Startle Deficits

PubMed Central

Sadeh, Naomi; Verona, Edelyn

2012-01-01

A long-standing debate is the extent to which psychopathy is characterized by a fundamental deficit in attention or emotion. We tested the hypothesis that the interplay of emotional and attentional systems is critical for understanding processing deficits in psychopathy. Sixty-three offenders were assessed using the Psychopathy Checklist: Screening Version. Event-related brain potentials (ERPs) and fear-potentiated startle (FPS) were collected while participants viewed pictures selected to disentangle an existing confound between perceptual complexity and emotional content in the pictures typically used to study fear deficits in psychopathy. As predicted, picture complexity moderated emotional processing deficits. Specifically, the affective-interpersonal features of psychopathy were associated with greater allocation of attentional resources to processing emotional stimuli at initial perception (visual N1) but only when picture stimuli were visually-complex. Despite this, results for the late positive potential indicated that emotional pictures were less attentionally engaging and held less motivational significance for individuals high in affective-interpersonal traits. This deficient negative emotional processing was observed later in their reduced defensive fear reactivity (FPS) to high-complexity unpleasant pictures. In contrast, the impulsive-antisocial features of psychopathy were associated with decreased sensitivity to picture complexity (visual N1) and unrelated to emotional processing as assessed by ERP and FPS. These findings are the first to demonstrate that picture complexity moderates FPS deficits and implicate the interplay of attention and emotional systems as deficient in psychopathy. PMID:22187225

Review: can diet influence the selective advantage of mitochondrial DNA haplotypes?

PubMed

Ballard, J William O; Youngson, Neil A

2015-11-05

This review explores the potential for changes in dietary macronutrients to differentially influence mitochondrial bioenergetics and thereby the frequency of mtDNA haplotypes in natural populations. Such dietary modification may be seasonal or result from biogeographic or demographic shifts. Mechanistically, mtDNA haplotypes may influence the activity of the electron transport system (ETS), retrograde signalling to the nuclear genome and affect epigenetic modifications. Thus, differential provisioning by macronutrients may lead to selection through changes in the levels of ATP production, modulation of metabolites (including AMP, reactive oxygen species (ROS) and the NAD(+)/NADH ratio) and potentially complex epigenetic effects. The exquisite complexity of dietary influence on haplotype frequency is further illustrated by the fact that macronutrients may differentially influence the selective advantage of specific mutations in different life-history stages. In Drosophila, complex I mutations may affect larval growth because dietary nutrients are fed through this complex in immaturity. In contrast, the majority of electrons are provided to complex III in adult flies. We conclude the review with a case study that considers specific interactions between diet and complex I of the ETS. Complex I is the first enzyme of the mitochondrial ETS and co-ordinates in the oxidation of NADH and transfer of electrons to ubiquinone. Although the supposition that mtDNA variants may be selected upon by dietary macronutrients could be intuitively consistent to some and counter intuitive to others, it must face a multitude of scientific hurdles before it can be recognized. © 2015 Authors.

Shame, Dissociation, and Complex PTSD Symptoms in Traumatized Psychiatric and Control Groups: Direct and Indirect Associations With Relationship Distress.

PubMed

Dorahy, Martin J; Corry, Mary; Black, Rebecca; Matheson, Laura; Coles, Holly; Curran, David; Seager, Lenaire; Middleton, Warwick; Dyer, Kevin F W

2017-04-01

Elevated shame and dissociation are common in dissociative identity disorder (DID) and chronic posttraumatic stress disorder (PTSD) and are part of the constellation of symptoms defined as complex PTSD. Previous work examined the relationship between shame, dissociation, and complex PTSD and whether they are associated with intimate relationship anxiety, relationship depression, and fear of relationships. This study investigated these variables in traumatized clinical samples and a nonclinical community group. Participants were drawn from the DID (n = 20), conflict-related chronic PTSD (n = 65), and nonclinical (n = 125) populations and completed questionnaires assessing the variables of interest. A model examining the direct impact of shame and dissociation on relationship functioning, and their indirect effect via complex PTSD symptoms, was tested through path analysis. The DID sample reported significantly higher dissociation, shame, complex PTSD symptom severity, relationship anxiety, relationship depression, and fear of relationships than the other two samples. Support was found for the proposed model, with shame directly affecting relationship anxiety and fear of relationships, and pathological dissociation directly affecting relationship anxiety and relationship depression. The indirect effect of shame and dissociation via complex PTSD symptom severity was evident on all relationship variables. Shame and pathological dissociation are important for not only the effect they have on the development of other complex PTSD symptoms, but also their direct and indirect effects on distress associated with relationships. © 2016 Wiley Periodicals, Inc.

Setting and measuring team goals and objectives for improved management of forestry research

Treesearch

Scott J. Josiah

1999-01-01

As our world becomes more complex and diverse, many forestry research organizations are responding by adopting more interdisciplinary and collaborative research programs. Our rapidly increasing knowledge of the ecological, social, and economic factors affecting forestry and natural resource management makes it simply untenable to expect that complex problems can be...

Regenerating Rural Social Space? Teacher Education for Rural-Regional Sustainability

ERIC Educational Resources Information Center

Reid, Jo-Anne; Green, Bill; Cooper, Maxine; Hastings, Wendy; Lock, Graeme; White, Simone

2010-01-01

The complex interconnection among issues affecting rural-regional sustainability requires an equally complex program of research to ensure the attraction and retention of high-quality teachers for rural children. The educational effects of the construction of the rural within a deficit discourse are highlighted. A concept of rural social space is…

Developing Student Interest: An Overview of the Research and Implications for Geoscience Education Research and Teaching Practice

ERIC Educational Resources Information Center

van der Hoeven Kraft, Katrien J.

2017-01-01

Interest is a complex interplay between affective and cognitive components that drive motivation. Over decades of work in the educational psychology community, a theoretical framework has emerged that explains this complex interplay. Interest is initially externally triggered (triggered situational interest), which, through support, can become…

Extruded foams prepared from high amylose starch with sodium stearate to form amylose inclusion complexes

USDA-ARS?s Scientific Manuscript database

Starch foams were prepared from high amylose corn starch in the presence and absence of sodium stearate and PVOH to determine how the formation of amylose-sodium stearate inclusion complexes and the addition of PVOH would affect foam properties. Low extrusion temperatures were used, and X-ray diffra...