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1.
Heliyon ; 9(9): e19909, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37809569

RESUMO

The rise in popularity of Chat GPT, an advanced language model that uses deep learning techniques to simulate human-like conversation, has raised concerns about its potential misuse, particularly in academic contexts. The present study (N = 283) explored the relationship between personality traits and the intention to use chatbot-generated texts for academic cheating. Among the HEXACO and Dark Triad traits, Honesty-Humility, Conscientiousness, Openness to Experience (all negative), Machiavellianism, narcissism, and psychopathy (all positive) were significant predictor variables. A multiple regression analysis showed that Honesty-Humility had the most robust association with the intention to use chatbot-generated texts for academic cheating. Further analyses on the facet level revealed that the fairness facet of Honesty-Humility was the most predictive, suggesting that individuals high in Honesty-Humility refrain from using chatbot-generated texts for academic cheating as they prioritize fairness over their own interests. Promoting Honesty-Humility and its fairness facet can be a valuable approach to promoting ethical behavior in academic and other contexts.

2.
Front Psychol ; 11: 825, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508704

RESUMO

Many psychological phenomena have a multilevel structure (e.g., individuals within teams or events within individuals). In these cases, the proportion of between-variance to total-variance (i.e., the sum between-variance and within-variance) is of special importance and usually estimated by the intraclass coefficient (1) [ICC(1)]. Our contribution firstly shows via mathematical proof that measurement error increases the within-variance, which in turn decreases the ICC(1). Further, we provide a numerical example, and examine the RMSEs, alpha error rates and the inclusion of zero in the confidence intervals for ICC(1) estimation with and without measurement error. Secondly, we propose two corrections [i.e., the reliability-adjusted ICC(1) and the measurement model-based ICC(1)] that yield correct estimates for the ICC(1), and prove that they are unaffected by measurement error mathematically. Finally, we discuss our findings, point out examples of the underestimation of the ICC(1) in the literature, and reinterpret the results of these examples in the light of our new estimator. We also illustrate the potential application of our work to other ICCs. Finally, we conclude that measurement error distorts the ICC(1) to a non-negligible extent.

3.
Front Psychol ; 11: 877, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508713

RESUMO

This study addresses three questions: How often and how consistently do predictors for emotion regulation choice occur in daily life? What predicts emotion regulation choice in daily life? How do predictors for emotion regulation choice interact in daily life? We examined emotion regulation goals (i.e., prohedonic and social goals), situational factors (i.e., perceived control, expected reoccurrence, and emotional intensity), and emotion regulation strategies (i.e., active coping, distraction, rumination, cognitive reappraisal, and expressive suppression) in negative emotion events. A total of 110 individuals (65% female) participated in an experience sampling study and received beeps, five times a day over the course of 9 days. We used a random intercept model to estimate our results. Emotion regulation goals and situational factors vary strongly in different events within the same person. Emotion regulation strategies, effective in changing the emotional experience, are crucial for prohedonic goals, whereas expressive suppression is important for social goals. Perceived control was positively associated with putatively adaptive strategies. Emotional intensity and expected reoccurrence were negatively associated with putatively adaptive strategies. Emotional intensity was positively associated with putatively maladaptive strategies. Emotion regulation strategies were not associated with the interaction of emotion regulation goals and situational factors. We conclude that emotion regulation goals and situational factors are extremely context-dependent, suggesting that they should be treated as states. Emotion regulation goals appear to have a functional association with strategies for prohedonic and social goals. The associations between situational factors and strategies in daily life appear to be largely different from the results found in the laboratory, emphasizing the importance of experience sampling studies.

4.
Mol Cell ; 58(6): 1067-78, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26009280

RESUMO

Small heat shock proteins (sHsps) are ubiquitous molecular chaperones that prevent the aggregation of unfolding proteins during proteotoxic stress. In Caenorhabditis elegans, Sip1 is the only sHsp exclusively expressed in oocytes and embryos. Here, we demonstrate that Sip1 is essential for heat shock survival of reproducing adults and embryos. X-ray crystallography and electron microscopy revealed that Sip1 exists in a range of well-defined globular assemblies consisting of two half-spheres, each made of dimeric "spokes." Strikingly, the oligomeric distribution of Sip1 as well as its chaperone activity depend on pH, with a trend toward smaller species and higher activity at acidic conditions such as present in nematode eggs. The analysis of the interactome shows that Sip1 has a specific substrate spectrum including proteins that are essential for embryo development.


Assuntos
Proteínas de Caenorhabditis elegans/química , Proteínas de Choque Térmico Pequenas/química , Chaperonas Moleculares/química , Conformação Proteica , Sequência de Aminoácidos , Animais , Western Blotting , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/classificação , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Microscopia Crioeletrônica , Cristalografia por Raios X , Proteínas de Choque Térmico Pequenas/genética , Proteínas de Choque Térmico Pequenas/metabolismo , Concentração de Íons de Hidrogênio , Modelos Moleculares , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Dados de Sequência Molecular , Mutação , Filogenia , Ligação Proteica , Multimerização Proteica , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Homologia de Sequência de Aminoácidos , Temperatura
5.
Mol Cell Biol ; 34(12): 2147-61, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24687852

RESUMO

Mutations in the leucine-rich repeat kinase 2 gene (LRRK2) are associated with familial and sporadic Parkinson's disease (PD). LRRK2 is a complex protein that consists of multiple domains, including predicted C-terminal WD40 repeats. In this study, we analyzed functional and molecular features conferred by the WD40 domain. Electron microscopic analysis of the purified LRRK2 C-terminal domain revealed doughnut-shaped particles, providing experimental evidence for its WD40 fold. We demonstrate that LRRK2 WD40 binds and sequesters synaptic vesicles via interaction with vesicle-associated proteins. In fact, a domain-based pulldown approach combined with mass spectrometric analysis identified LRRK2 as being part of a highly specific protein network involved in synaptic vesicle trafficking. In addition, we found that a C-terminal sequence variant associated with an increased risk of developing PD, G2385R, correlates with a reduced binding affinity of LRRK2 WD40 to synaptic vesicles. Our data demonstrate a critical role of the WD40 domain within LRRK2 function.


Assuntos
Neurônios/metabolismo , Domínios e Motivos de Interação entre Proteínas , Proteínas Serina-Treonina Quinases/química , Proteínas Serina-Treonina Quinases/metabolismo , Vesículas Sinápticas/metabolismo , Animais , Células Cultivadas , Humanos , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Mutantes/química , Proteínas Mutantes/metabolismo , Mutação/genética , Neuropeptídeos/metabolismo , Neurotoxinas/toxicidade , Doença de Parkinson/enzimologia , Doença de Parkinson/genética , Doença de Parkinson/patologia , Ligação Proteica , Mapeamento de Interação de Proteínas , Proteínas Serina-Treonina Quinases/ultraestrutura , Receptores de Quinase C Ativada , Relação Estrutura-Atividade , Sinapses/metabolismo
6.
Proc Natl Acad Sci U S A ; 110(40): E3780-9, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24043785

RESUMO

The small heat shock protein αB-crystallin is an oligomeric molecular chaperone that binds aggregation-prone proteins. As a component of the proteostasis system, it is associated with cataract, neurodegenerative diseases, and myopathies. The structural determinants for the regulation of its chaperone function are still largely elusive. Combining different experimental approaches, we show that phosphorylation-induced destabilization of intersubunit interactions mediated by the N-terminal domain (NTD) results in the remodeling of the oligomer ensemble with an increase in smaller, activated species, predominantly 12-mers and 6-mers. Their 3D structures determined by cryo-electron microscopy and biochemical analyses reveal that the NTD in these species gains flexibility and solvent accessibility. These modulated properties are accompanied by an increase in chaperone activity in vivo and in vitro and a more efficient cooperation with the heat shock protein 70 system in client folding. Thus, the modulation of the structural flexibility of the NTD, as described here for phosphorylation, appears to regulate the chaperone activity of αB-crystallin rendering the NTD a conformational sensor for nonnative proteins.


Assuntos
Modelos Moleculares , Chaperonas Moleculares/química , Conformação Proteica , Cadeia B de alfa-Cristalina/química , Cromatografia em Gel , Clonagem Molecular , Microscopia Crioeletrônica , Eletroforese em Gel de Poliacrilamida , Proteínas de Choque Térmico HSP70/metabolismo , Células HeLa , Humanos , Processamento de Imagem Assistida por Computador , Chaperonas Moleculares/metabolismo , Fosforilação , Corantes de Rosanilina , Cadeia B de alfa-Cristalina/metabolismo
7.
J Soc Psychol ; 152(5): 623-38, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22931000

RESUMO

We investigated how the availability of self-control resources affects risk-taking inclinations and behaviors. We proposed that risk-taking often occurs from suboptimal decision processes and heuristic information processing (e.g., when a smoker suppresses or neglects information about the health risks of smoking). Research revealed that depleted self-regulation resources are associated with reduced intellectual performance and reduced abilities to regulate spontaneous and automatic responses (e.g., control aggressive responses in the face of frustration). The present studies transferred these ideas to the area of risk-taking. We propose that risk-taking is increased when individuals find themselves in a state of reduced cognitive self-control resources (ego-depletion). Four studies supported these ideas. In Study 1, ego-depleted participants reported higher levels of sensation seeking than non-depleted participants. In Study 2, ego-depleted participants showed higher levels of risk-tolerance in critical road traffic situations than non-depleted participants. In Study 3, we ruled out two alternative explanations for these results: neither cognitive load nor feelings of anger mediated the effect of ego-depletion on risk-taking. Finally, Study 4 clarified the underlying psychological process: ego-depleted participants feel more cognitively exhausted than non-depleted participants and thus are more willing to take risks. Discussion focuses on the theoretical and practical implications of these findings.


Assuntos
Ego , Assunção de Riscos , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Psicológicos , Autoimagem , Adulto Jovem
8.
J Biol Chem ; 287(9): 6892-903, 2012 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-22223481

RESUMO

Hypochlorite is a powerful oxidant produced by neutrophils to kill invading microorganisms. Despite this important physiological role of HOCl in fighting bacterial infections, no hypochlorite-specific stress response has been identified yet. Here, we identified a hypochlorite-responsive transcription factor, YjiE, which is conserved in proteobacteria and eukaryotes. YjiE forms unusual dodecameric ring-like structures in vitro that undergo large DNA-induced conformational changes to form dimers and tetramers as shown by transmission electron microscopy and analytical ultracentrifugation. Such smaller oligomers are predominant in hypochlorite-stressed cells and are the active species as shown by fluorescence anisotropy and analytical ultracentrifugation. YjiE regulates a large number of genes upon hypochlorite stress. Among them are genes involved in cysteine, methionine biosynthesis, and sulfur metabolism (up-regulated) and genes involved in iron acquisition and homeostasis (down-regulated), thus supposedly replenishing oxidized metabolites and decreasing the hypochlorite-mediated amplification of intracellular reactive oxygen species. As a result, YjiE specifically confers hypochlorite resistance to E. coli cells. Thus, to our knowledge, YjiE is the first described hypochlorite-specific transcription factor.


Assuntos
Proteínas de Escherichia coli/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Ácido Hipocloroso/farmacologia , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Fatores de Transcrição/metabolismo , Sequência de Aminoácidos , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Desinfetantes/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Dados de Sequência Molecular , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Espécies Reativas de Oxigênio/metabolismo , Fatores de Transcrição/genética
9.
Anxiety Stress Coping ; 25(5): 477-89, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21506026

RESUMO

In two experimental studies we found that participants who recalled a highly traumatic autobiographical event (trauma recall) compared with a lesser traumatic event (stress recall) reported having increasingly grown (posttraumatic growth, PTG). Moreover, participants who recalled a traumatic (vs. stressful) event perceived more death-related thoughts (Study 1) and reported coping with this event in a more emotion-focused and in a less problem-focused way (Study 2). Mediation analyzes revealed that the effect of trauma versus stress recall on PTG was mediated by emphasizing the positive, a subscale of emotion-focused coping. These results imply that growth resulting from traumatic events can be traced back to an illusion. No evidence was found that real PTG took place or that the effects shown resulted from death-related thoughts (terror management theory).


Assuntos
Adaptação Psicológica , Acontecimentos que Mudam a Vida , Adulto , Atitude Frente a Morte , Emoções , Feminino , Humanos , Masculino , Rememoração Mental , Inquéritos e Questionários
10.
Proc Natl Acad Sci U S A ; 108(51): 20491-6, 2011 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-22143763

RESUMO

The molecular chaperone αB-crystallin, the major player in maintaining the transparency of the eye lens, prevents stress-damaged and aging lens proteins from aggregation. In nonlenticular cells, it is involved in various neurological diseases, diabetes, and cancer. Given its structural plasticity and dynamics, structure analysis of αB-crystallin presented hitherto a formidable challenge. Here we present a pseudoatomic model of a 24-meric αB-crystallin assembly obtained by a triple hybrid approach combining data from cryoelectron microscopy, NMR spectroscopy, and structural modeling. The model, confirmed by cross-linking and mass spectrometry, shows that the subunits interact within the oligomer in different, defined conformations. We further present the molecular architectures of additional well-defined αB-crystallin assemblies with larger or smaller numbers of subunits, provide the mechanism how "heterogeneity" is achieved by a small set of defined structural variations, and analyze the factors modulating the oligomer equilibrium of αB-crystallin and thus its chaperone activity.


Assuntos
Cristalino/metabolismo , Cadeia B de alfa-Cristalina/química , Reagentes de Ligações Cruzadas/química , Microscopia Crioeletrônica/métodos , Proteínas de Choque Térmico/metabolismo , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Espectroscopia de Ressonância Magnética/métodos , Espectrometria de Massas/métodos , Microscopia Eletrônica/métodos , Modelos Moleculares , Conformação Molecular , Mutagênese Sítio-Dirigida , Conformação Proteica , Estrutura Secundária de Proteína
12.
Psychol Bull ; 137(4): 517-37, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21534650

RESUMO

Research on bystander intervention has produced a great number of studies showing that the presence of other people in a critical situation reduces the likelihood that an individual will help. As the last systematic review of bystander research was published in 1981 and was not a quantitative meta-analysis in the modern sense, the present meta-analysis updates the knowledge about the bystander effect and its potential moderators. The present work (a) integrates the bystander literature from the 1960s to 2010, (b) provides statistical tests of potential moderators, and (c) presents new theoretical and empirical perspectives on the novel finding of non-negative bystander effects in certain dangerous emergencies as well as situations where bystanders are a source of physical support for the potentially intervening individual. In a fixed effects model, data from over 7,700 participants and 105 independent effect sizes revealed an overall effect size of g = -0.35. The bystander effect was attenuated when situations were perceived as dangerous (compared with non-dangerous), perpetrators were present (compared with non-present), and the costs of intervention were physical (compared with non-physical). This pattern of findings is consistent with the arousal-cost-reward model, which proposes that dangerous emergencies are recognized faster and more clearly as real emergencies, thereby inducing higher levels of arousal and hence more helping. We also identified situations where bystanders provide welcome physical support for the potentially intervening individual and thus reduce the bystander effect, such as when the bystanders were exclusively male, when they were naive rather than passive confederates or only virtually present persons, and when the bystanders were not strangers.


Assuntos
Emergências/psicologia , Comportamento de Ajuda , Controles Informais da Sociedade/métodos , Acidentes/psicologia , Nível de Alerta/fisiologia , Viés , Fatores de Confusão Epidemiológicos , Vítimas de Crime/psicologia , Medo/psicologia , Feminino , Humanos , Masculino , Identificação Social , Violência/psicologia
13.
Psychol Bull ; 137(3): 367-90, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21341887

RESUMO

In recent years, there has been a surge in the quantity of media content that glorifies risk-taking behavior, such as risky driving, extreme sports, or binge drinking. The authors conducted a meta-analysis involving more than 80,000 participants and 105 independent effect sizes to examine whether exposure to such media depictions increased their recipients' risk-taking inclinations. A positive connection was found for overall, combined risk taking (g=.41); as well as its underlying dimensions: risk-taking behaviors (g=.41), risk-positive cognitions and attitudes (g=.35), and risk-positive emotions (g=.56). This effect was observed across varying research methods (experimental, correlational, longitudinal); types of media (video games, movies, advertising, TV, music); and differing risk-related outcome measures (e.g., smoking, drinking, risky driving, sexual behavior). Multiple moderator analyses revealed 2 theoretically new boundary conditions for sociocognitive models. First, the effect was stronger for active (i.e., video games) than for passive (e.g., film, music) exposure to risk-glorifying media content. Second, the effect was stronger when there was a high degree of contextual fit between the media content and type of risk-taking measure. The theoretical, practical, and societal implications of the present research synthesis are discussed.


Assuntos
Cognição , Emoções , Meios de Comunicação de Massa , Assunção de Riscos , Comportamento Social , Adolescente , Comportamento do Adolescente/psicologia , Adulto , Publicidade , Distribuição por Idade , Consumo de Bebidas Alcoólicas/psicologia , Atitude Frente a Saúde , Condução de Veículo/psicologia , Estudos Transversais , Feminino , Humanos , Masculino , Música/psicologia , Comportamento Sexual/psicologia , Fumar , Esportes/psicologia , Jogos de Vídeo/psicologia , Adulto Jovem
14.
J Exp Psychol Gen ; 140(1): 51-62, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21171802

RESUMO

Previous studies on the impact of perceived threat on confirmatory information search (selective exposure) in the context of decision making have yielded mixed results. Some studies have suggested that confirmatory information search is reduced, yet others have found contradictory effects. The present series of 5 studies consistently found that the crucial moderator for these inconsistent findings was whether the induced threat was contextually related to the subsequent decision and information search tasks. Contextual incongruence (e.g., an induction of terrorist threat followed by an economic decision case) results in reduced levels of confirmatory information search, whereas a congruent threat (e.g., an induction of terrorist threat followed by a decision case on terrorism) results in increased levels of confirmatory information search. Analyses of the underlying psychological processes revealed that decision-unrelated threat inductions increase decision makers' experienced decision uncertainty, thus reducing confirmatory information search.


Assuntos
Tomada de Decisões/fisiologia , Comportamento de Busca de Informação/fisiologia , Terrorismo/psicologia , Incerteza , Adolescente , Adulto , Idoso , Feminino , Generalização Psicológica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudantes/psicologia , Adulto Jovem
15.
Br J Soc Psychol ; 49(Pt 4): 745-63, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20100393

RESUMO

Previous research has found that people prefer information that supports rather than conflicts with their decisions (selective exposure). In the present three studies, we investigated the impact of collectivism and individualism on this bias. First, based on previous findings showing that collectivists compared to individualists are inclined to seek the 'middle way' and tend towards self-criticism, we predicted and found that the confirmation bias was more negative among collectivists compared to individualists. Second, we assumed that the difference between selected supporting versus conflicting information would move more in favour of conflicting information among both collectivists and individualists when the domain was important to them. As predicted (chronic and primed), collectivists and individualists, respectively, sought more conflicting (compared to supporting) information depending on whether collectivistic (e.g., the family) or individualistic (e.g., one's own uniqueness) attributes were important.


Assuntos
Comportamento de Escolha , Comparação Transcultural , Comportamento de Busca de Informação , Valores Sociais , Adolescente , Adulto , Idoso , Altruísmo , Ásia/etnologia , Conflito Psicológico , Europa (Continente)/etnologia , Feminino , Humanos , Individualidade , Masculino , Pessoa de Meia-Idade , Motivação , Estados Unidos/etnologia
16.
Biochim Biophys Acta ; 1793(11): 1738-48, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19699241

RESUMO

Small heat shock proteins (sHsps) are ubiquitous molecular chaperones which prevent the nonspecific aggregation of non-native proteins. Five potential sHsps exist in the parasite Toxoplasma gondii. They are located in different intracellular compartments including mitochondria and are differentially expressed during the parasite's life cycle. Here, we analyzed the structural and functional properties of all five proteins. Interestingly, this first in vitro characterization of sHsps from protists showed that all T. gondii sHsps exhibit the characteristic properties of sHsps such as oligomeric structure and chaperone activity. However, differences in their quaternary structure and in their specific chaperone properties exist. On the structural level, the T. gondii sHsps can be divided in small (12-18 subunits) and large (24-32 subunits) oligomers. Furthermore, they differ in their interaction with non-native proteins. While some bind substrates tightly, others interact more transiently. The chaperone activity of the three more mono-disperse T. gondii sHsps is regulated by temperature with a decrease in temperature leading to the activation of chaperone activity, suggesting an adaption to specific steps of the parasite's life cycle.


Assuntos
Proteínas de Choque Térmico Pequenas/genética , Filogenia , Proteínas de Protozoários/genética , Toxoplasma/genética , Motivos de Aminoácidos/fisiologia , Animais , Proteínas de Choque Térmico Pequenas/metabolismo , Estrutura Quaternária de Proteína/fisiologia , Proteínas de Protozoários/metabolismo , Relação Estrutura-Atividade , Toxoplasma/metabolismo
17.
Pers Soc Psychol Bull ; 35(10): 1395-409, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19596767

RESUMO

The present studies investigated why video racing games increase players' risk-taking inclinations. Four studies reveal that playing video racing games increases risk taking in a subsequent simulated road traffic situation, as well as risk-promoting cognitions and emotions, blood pressure, sensation seeking, and attitudes toward reckless driving. Study 1 ruled out the role of experimental demand in creating such effects. Studies 2 and 3 showed that the effect of playing video racing games on risk taking was partially mediated by changes in self-perceptions as a reckless driver. These effects were evident only when the individual played racing games that reward traffic violations rather than racing games that do not reward traffic violations (Study 3) and when the individual was an active player of such games rather than a passive observer (Study 4). In sum, the results underline the potential negative impact of racing games on traffic safety.


Assuntos
Nível de Alerta , Condução de Veículo/psicologia , Cultura , Comportamento Imitativo , Assunção de Riscos , Jogos de Vídeo , Acidentes de Trânsito/psicologia , Adulto , Simulação por Computador , Feminino , Generalização da Resposta , Humanos , Masculino , Pessoa de Meia-Idade , Motivação , Autoimagem , Conformidade Social , Adulto Jovem
18.
J Mol Biol ; 378(2): 362-74, 2008 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-18353362

RESUMO

Small heat shock proteins (sHsps) are a widespread and diverse class of molecular chaperones. In vivo, sHsps contribute to thermotolerance. Recent evidence suggests that their function in the cellular chaperone network is to maintain protein homeostasis by complexing a variety of non-native proteins. One of the most characteristic features of sHsps is their organization into large, sphere-like structures commonly consisting of 12 or 24 subunits. Here, we investigated the functional and structural properties of Hsp20.2, an sHsp from Archaeoglobus fulgidus, in comparison to its relative, Hsp16.5 from Methanocaldococcus jannaschii. Hsp20.2 is active in suppressing the aggregation of different model substrates at physiological and heat-stress temperatures. Electron microscopy showed that Hsp20.2 forms two distinct types of octahedral oligomers of slightly different sizes, indicating certain structural flexibility of the oligomeric assembly. By three-dimensional analysis of electron microscopic images of negatively stained specimens, we were able to reconstitute 3D models of the assemblies at a resolution of 19 A. Under conditions of heat stress, the distribution of the structurally different Hsp20.2 assemblies changed, and this change was correlated with an increased chaperone activity. In analogy to Hsp20.2, Hsp16.5 oligomers displayed structural dynamics and exhibited increased chaperone activity under conditions of heat stress. Thus, temperature-induced conformational regulation of the activity of sHsps may be a general phenomenon in thermophilic archaea.


Assuntos
Proteínas Arqueais/química , Archaeoglobus fulgidus , Proteínas de Choque Térmico HSP20/química , Temperatura Alta , Proteínas de Choque Térmico/química , Microscopia Eletrônica , Conformação Proteica
19.
Pers Soc Psychol Bull ; 32(3): 365-77, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16455863

RESUMO

It was hypothesized that intrinsic religiousness helps to cope with increased salience of terrorism. Intrinsically religious and non-religious participants were told that it is highly probable or highly improbable, respectively, that terrorist attacks will occur in Germany. High probability of terrorism only negatively affected the mood of non-religious participants but not of intrinsically religious participants (Study 1). Using as a realistic context of investigation the terrorist suicide bombings in Istanbul, the authors replicated this finding and shed some light on the underlying psychological processes (Study 2): On the day of the terrorist attacks (high salience of terrorism), non-religious participants experienced less positive emotions and less self-efficacy than did intrinsically religious participants. Two months later (low salience of terrorism), no differences were found between non-religious and intrinsically religious participants with regard to mood and self-efficacy. Mediational analyses suggested that the mood effects were associated with differences in the reported sense of self-efficacy.


Assuntos
Adaptação Psicológica/fisiologia , Afeto/fisiologia , Religião e Psicologia , Autoeficácia , Terrorismo/psicologia , Adolescente , Adulto , Análise de Variância , Feminino , Alemanha , Humanos , Masculino , Pessoa de Meia-Idade
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