The Experts below are selected from a list of 9975465 Experts worldwide ranked by ideXlab platform
John L Foster - One of the best experts on this subject based on the ideXlab platform.
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self association of the lentivirus protein nef
Retrovirology, 2010Co-Authors: Youn Tae Kwak, Brenda Temple, Alexa Raney, Lillian S Kuo, Sarah J Denial, Victor J Garcia, John L FosterAbstract:Background The HIV-1 pathogenic factor, Nef, is a multifunctional protein present in the cytosol and on membranes of infected cells. It has been proposed that a spatial and temporal regulation of the conformation of Nef sequentially matches Nef's multiple functions to the process of virion production. Further, it has been suggested that dimerization is required for multiple Nef activities. A dimerization interface has been proposed based on intermolecular contacts between Nefs within hexagonal Nef/FynSH3 crystals. The proposed dimerization interface consists of the hydrophobic B-helix and flanking salt bridges between R105 and D123. Here, we test whether Nef Self-Association is mediated by this interface and address the overall significance of oligomerization.
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self association of the lentivirus protein nef
Retrovirology, 2010Co-Authors: Youn Tae Kwak, Brenda Temple, Alexa Raney, Lillian S Kuo, Sarah J Denial, Victor J Garcia, John L FosterAbstract:The HIV-1 pathogenic factor, Nef, is a multifunctional protein present in the cytosol and on membranes of infected cells. It has been proposed that a spatial and temporal regulation of the conformation of Nef sequentially matches Nef's multiple functions to the process of virion production. Further, it has been suggested that dimerization is required for multiple Nef activities. A dimerization interface has been proposed based on intermolecular contacts between Nefs within hexagonal Nef/FynSH3 crystals. The proposed dimerization interface consists of the hydrophobic B-helix and flanking salt bridges between R105 and D123. Here, we test whether Nef Self-Association is mediated by this interface and address the overall significance of oligomerization. By co-immunoprecipitation assays, we demonstrated that HIV-1Nef exists as monomers and oligomers with about half of the Nef protomers oligomerized. Nef oligomers were found to be present in the cytosol and on membranes. Removal of the myristate did not enhance the oligomerization of soluble Nef. Also, SIVNef oligomerizes despite lacking a dimerization interface functionally homologous to that proposed for HIV-1Nef. Moreover, HIV-1Nef and SIVNef form hetero-oligomers demonstrating the existence of homologous oligomerization interfaces that are distinct from that previously proposed (R105-D123). Intracellular cross-linking by formaldehyde confirmed that SF2Nef dimers are present in intact cells, but surprisingly Self-Association was dependent on R105, but not D123. SIVMAC239Nef can be cross-linked at its only cysteine, C55, and SF2Nef is also cross-linked, but at C206 instead of C55, suggesting that Nefs exhibit multiple dimeric structures. ClusPro dimerization analysis of HIV-1Nef homodimers and HIV-1Nef/SIVNef heterodimers identified a new potential dimerization interface, including a dibasic motif at R105-R106 and a six amino acid hydrophobic surface. We have demonstrated significant levels of intracellular Nef oligomers by immunoprecipitation from cellular extracts. However, our results are contrary to the identification of salt bridges between R105 and D123 as necessary for Self-Association. Importantly, binding between HIV-1Nef and SIVNef demonstrates evolutionary conservation and therefore significant function(s) for oligomerization. Based on modeling studies of Nef Self-Association, we propose a new dimerization interface. Finally, our findings support a stochastic model of Nef function with a dispersed intracellular distribution of Nef oligomers.
Jessica L Tracy - One of the best experts on this subject based on the ideXlab platform.
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two replicable suppressor situations in personality research
Multivariate Behavioral Research, 2004Co-Authors: Delroy L Paulhus, Richard W Robins, Kali H Trzesniewski, Jessica L TracyAbstract:Suppressor situations occur when the simultaneous inclusion of two predictors improves one or both validities. A common allegation is that suppressor effects rarely replicate and have little substantive import. We present substantive examples from two established research domains to counter this skepticism. In the first domain, we show how measures of guilt and shame act consistently as mutual suppressors: Adding shame into a regression equation increases the negative association between guilt and aggression, whereas adding guilt increases the positive association between shame and aggression. In the second domain, we show how the effects of self-esteem and narcissism operate consistently as mutual suppressors: That is, adding narcissism into a regression equation increases the negative association between self-esteem and antisocial behavior, whereas adding self-esteem increases the positive association between narcissism and antisocial behavior. Discussion addresses the different implications for suppres...
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two replicable suppressor situations in personality research
Multivariate Behavioral Research, 2004Co-Authors: Delroy L Paulhus, Richard W Robins, Kali H Trzesniewski, Jessica L TracyAbstract:Suppressor situations occur when the simultaneous inclusion of two predictors improves one or both validities. A common allegation is that suppressor effects rarely replicate and have little substantive import. We present substantive examples from two established research domains to counter this skepticism. In the first domain, we show how measures of guilt and shame act consistently as mutual suppressors: Adding shame into a regression equation increases the negative association between guilt and aggression, whereas adding guilt increases the positive association between shame and aggression. In the second domain, we show how the effects of self-esteem and narcissism operate consistently as mutual suppressors: That is, adding narcissism into a regression equation increases the negative association between self-esteem and antisocial behavior, whereas adding self-esteem increases the positive association between narcissism and antisocial behavior. Discussion addresses the different implications for suppressors in theoretical and variable selection applications.
Youn Tae Kwak - One of the best experts on this subject based on the ideXlab platform.
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self association of the lentivirus protein nef
Retrovirology, 2010Co-Authors: Youn Tae Kwak, Brenda Temple, Alexa Raney, Lillian S Kuo, Sarah J Denial, Victor J Garcia, John L FosterAbstract:Background The HIV-1 pathogenic factor, Nef, is a multifunctional protein present in the cytosol and on membranes of infected cells. It has been proposed that a spatial and temporal regulation of the conformation of Nef sequentially matches Nef's multiple functions to the process of virion production. Further, it has been suggested that dimerization is required for multiple Nef activities. A dimerization interface has been proposed based on intermolecular contacts between Nefs within hexagonal Nef/FynSH3 crystals. The proposed dimerization interface consists of the hydrophobic B-helix and flanking salt bridges between R105 and D123. Here, we test whether Nef Self-Association is mediated by this interface and address the overall significance of oligomerization.
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self association of the lentivirus protein nef
Retrovirology, 2010Co-Authors: Youn Tae Kwak, Brenda Temple, Alexa Raney, Lillian S Kuo, Sarah J Denial, Victor J Garcia, John L FosterAbstract:The HIV-1 pathogenic factor, Nef, is a multifunctional protein present in the cytosol and on membranes of infected cells. It has been proposed that a spatial and temporal regulation of the conformation of Nef sequentially matches Nef's multiple functions to the process of virion production. Further, it has been suggested that dimerization is required for multiple Nef activities. A dimerization interface has been proposed based on intermolecular contacts between Nefs within hexagonal Nef/FynSH3 crystals. The proposed dimerization interface consists of the hydrophobic B-helix and flanking salt bridges between R105 and D123. Here, we test whether Nef Self-Association is mediated by this interface and address the overall significance of oligomerization. By co-immunoprecipitation assays, we demonstrated that HIV-1Nef exists as monomers and oligomers with about half of the Nef protomers oligomerized. Nef oligomers were found to be present in the cytosol and on membranes. Removal of the myristate did not enhance the oligomerization of soluble Nef. Also, SIVNef oligomerizes despite lacking a dimerization interface functionally homologous to that proposed for HIV-1Nef. Moreover, HIV-1Nef and SIVNef form hetero-oligomers demonstrating the existence of homologous oligomerization interfaces that are distinct from that previously proposed (R105-D123). Intracellular cross-linking by formaldehyde confirmed that SF2Nef dimers are present in intact cells, but surprisingly Self-Association was dependent on R105, but not D123. SIVMAC239Nef can be cross-linked at its only cysteine, C55, and SF2Nef is also cross-linked, but at C206 instead of C55, suggesting that Nefs exhibit multiple dimeric structures. ClusPro dimerization analysis of HIV-1Nef homodimers and HIV-1Nef/SIVNef heterodimers identified a new potential dimerization interface, including a dibasic motif at R105-R106 and a six amino acid hydrophobic surface. We have demonstrated significant levels of intracellular Nef oligomers by immunoprecipitation from cellular extracts. However, our results are contrary to the identification of salt bridges between R105 and D123 as necessary for Self-Association. Importantly, binding between HIV-1Nef and SIVNef demonstrates evolutionary conservation and therefore significant function(s) for oligomerization. Based on modeling studies of Nef Self-Association, we propose a new dimerization interface. Finally, our findings support a stochastic model of Nef function with a dispersed intracellular distribution of Nef oligomers.
Boris N Solomonov - One of the best experts on this subject based on the ideXlab platform.
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hydrogen bonding in neat aliphatic alcohols the gibbs free energy of self association and molar fraction of monomer
Journal of Molecular Liquids, 2012Co-Authors: Igor A Sedov, Boris N SolomonovAbstract:Abstract The magnitudes of the Gibbs free energies of Self-Association for several primary aliphatic alcohols at 298 K are calculated. The fraction of monomeric molecules in bulk alcohols is determined. We started from the experimental data on the Gibbs free energies of vaporization of alcohols, and quantified the contributions from three types of solvation effects: non-specific van der Waals interactions, solvophobic effects, and hydrogen-bonding processes (Self-Association) using an extrathermodynamic approach. Calculated values for monomer fractions are compared and found to be in general agreement with the results obtained from various association models: CPA, NRHB, sPC-SAFT, and other data reported in literature. The influence of hydrogen bond cooperativity on the process of Self-Association is shown.
James Scott - One of the best experts on this subject based on the ideXlab platform.
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association between psychotic experiences and non accidental self injury results from a nationally representative survey of adolescents
Social Psychiatry and Psychiatric Epidemiology, 2019Co-Authors: Emily Hielscher, Melissa Connell, David Lawrence, Stephen R Zubrick, Jennifer Hafekost, James ScottAbstract:The association between psychotic experiences (PEs) and non-accidental self-injury (NASI; including self-harm and suicide attempts) is well established, although variables influencing this relationship have not been comprehensively examined. This study aimed to investigate (1) the cross-sectional PE–NASI association before and after adjustment for confounders, and (2) the individual contribution of each confounding and potentially mediating variable to the association. A random sample of Australian adolescents aged 14–17 years (n = 1998) completed self-report questions regarding any self-harm, suicidality or PEs experienced in the past 12 months in 2013–2014 as part of the Young Minds Matter Survey, a national household survey. We conducted logistic regression analyses to investigate the association between NASI and PEs, after controlling for confounders (sociodemographics, substance use, and parental mental illness) as well as the influence of potential mediators (major depression, bullying, psychological distress, sleep, self-esteem, disordered eating behaviour, social isolation, and intervention factors). Except for special messages, all PE subtypes (auditory and visual hallucinatory experiences [HEs], and two of the three delusional experiences [DEs]) were associated with NASI after adjustment for confounders (OR range: 2.60–5.21). Depression and psychological distress significantly influenced all PE–NASI associations, where depression appeared to fully explain the DE–NASI association, and partially attenuate the HE–NASI association. Variables such as parental mental illness, disordered eating behaviour, and social isolation had negligible effects in nearly all self-harm and attempted suicide models. Adolescents reporting any PE in the past 12 months reported increased likelihood of NASI in the same time period and, auditory HEs in particular, were strongly and independently associated with self-harm and suicide attempts. These results highlight the importance of PEs as indicators of risk of self-injurious behaviour among Australian youth.
