905 resultados para post-translational regulation


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We report the cloning and characterization in tobacco and Arabidopsis of a Vigna radiata L. (mung bean) promoter that controls the expression of VR-ACS1, an auxin-inducible ACC synthase gene. The VR-ACS1 promoter exhibits a very unusual behavior when studied in plants different from its original host, mung bean. GUS and luciferase in situ assays of transgenic plants containing VR-ACS1 promoter fusions show strong constitutive reporter gene expression throughout tobacco and Arabidopsis development. In vitro quantitative analyses show that transgenic plants harboring VR-ACS1 promoter-reporter constructs have on average 4-6 fold higher protein and activity levels of both reporter genes than plants transformed with comparable CaMV 35S promoter fusions. Similar transcript levels are present in VR-ACS1 and CaMV 35S promoter lines, suggesting that the high levels of gene product observed for the VR-ACS1 promoter are the combined result of transcriptional and translational activation. All tested deletion constructs retaining the core promoter region can drive strong constitutive promoter activity in transgenic plants. This is in contrast to mung bean, where expression of the native VR-ACS1 gene is almost undetectable in plants grown under normal conditions, but is rapidly and highly induced by a variety of stimuli. The constitutive behavior of the VR-ACS1 promoter in heterologous hosts is surprising, suggesting that the control mechanisms active in mung bean are impaired in tobacco and Arabidopsis. The 'aberrant' behavior of the VR-ACS1 promoter is further emphasized by its failure to respond to auxin and cycloheximide in heterologous hosts. VR-ACS1 promoter regulatory mechanisms seem to be different from all previously characterized auxin-inducible promoters.

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The question of how to develop leaders so that they are more effective in a variety of situations, roles and levels has inspired a voluminous amount of research. While leader development programs such as executive coaching and 360-degree feedback have been widely practiced to meet this demand within organisations, the research in this area has only scratched the surface. Drawing from the past literature and leadership practices, the current research conceptualised self-regulation, as a metacompetency that would assist leaders to further develop the specific competencies needed to perform effectively in their leadership role, leading to an increased rating of leader effectiveness and to enhanced group performance. To test this conceptualisation, a longitudinal field experimental study was conducted across ten months with a pre- and two post-test intervention designs with a matched control group. This longitudinal field experimental compared the difference in leader and team performance after receiving self-regulation intervention that was delivered by an executive coach. Leaders in experimental group also received feedback reports from 360-degree feedback at each stage. Participants were 40 leaders, 155 followers and 8 supervisors. Leaders’ performance was measured using a multi-source perceptual measure of leader performance and objective measures of team financial and assessment performance. Analyses using repeated measure of ANCOVA on pre-test and two post-tests responses showed a significant difference between leader and team performance between experimental and control group. Furthermore, leader competencies mediated the relationship between self-regulation and performance. The implications of these findings for the theory and practice of leadership development training programs and the impact on organisational performance are discussed.

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A longitudinal field experiment examined a leader self-regulation intervention in teams engaged in a Business Strategy Module (BSM) of a University course. The BSM, which is an integral part of the degree programme, involved teams of four or five individuals, under the direction of a leader, working on a (simulated) car manufacturing task over a period of 24. weeks. Various aspects of team performance contributed towards module assessment. All leaders received multi-source feedback of leader task-relevant capabilities (from the leader, followers and module tutor). Leaders were randomly allocated into a self-regulation intervention (15 leaders, 46 followers) or control (25 leaders, 109 followers) conditions. The intervention, which was run by an independent coach, was designed to improve leaders' use of self-regulatory processes to aid the development of task-relevant leadership competencies. Survey data was collected from the leaders and followers (on three occasions: pre- and two post-test intervention), team financial performance (three occasions: post-test) and a final team report (post-test). The leader self-regulation intervention led to increased followers' ratings of leader's effectiveness, higher team financial performance and higher final team grade compared to the control (non-intervention) condition. Furthermore, the benefits of the self-regulation intervention were mediated by leaders' attaining task-relevant competencies. © 2013.

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S-glutathionylation occurs when reactive oxygen or nitrogen species react with protein-cysteine thiols. Glutaredoxin-1 (Glrx) is a cytosolic enzyme which enzymatically catalyses the reduction in S-glutathionylation, conferring reversible signalling function to proteins with redox-sensitive thiols. Glrx can regulate vascular hypertrophy and inflammation by regulating the activity of nuclear factor κB (NF-κB) and actin polymerization. Vascular endothelial growth factor (VEGF)-induced endothelial cell (EC) migration is inhibited by Glrx overexpression. In mice overexpressing Glrx, blood flow recovery, exercise function and capillary density were significantly attenuated after hindlimb ischaemia (HLI). Wnt5a and soluble Fms-like tyrosine kinase-1 (sFlt-1) were enhanced in the ischaemic-limb muscle and plasma respectively from Glrx transgenic (TG) mice. A Wnt5a/sFlt-1 pathway had been described in myeloid cells controlling retinal blood vessel development. Interestingly, a Wnt5a/sFlt-1 pathway was found also to play a role in EC to inhibit network formation. S-glutathionylation of NF-κB components inhibits its activation. Up-regulated Glrx stimulated the Wnt5a/sFlt-1 pathway through enhancing NF-κB signalling. These studies show a novel role for Glrx in post-ischaemic neovascularization, which could define a potential target for therapy of impaired angiogenesis in pathological conditions including diabetes.

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Previous work has demonstrated that planning behaviours may be more adaptive than avoidance strategies in driving self-regulation, but ways of encouraging planning have not been investigated. The efficacy of an extended theory of planned behaviour (TPB) plus implementation intention based intervention to promote planning self-regulation in drivers across the lifespan was tested. An age stratified group of participants (N=81, aged 18-83 years) was randomly assigned to an experimental or control condition. The intervention prompted specific goal setting with action planning and barrier identification. Goal setting was carried out using an agreed behavioural contract. Baseline and follow-up measures of TPB variables, self-reported, driving self-regulation behaviours (avoidance and planning) and mobility goal achievements were collected using postal questionnaires. Like many previous efforts to change planned behaviour by changing its predictors using models of planned behaviour such as the TPB, results showed that the intervention did not significantly change any of the model components. However, more than 90% of participants achieved their primary driving goal, and self-regulation planning as measured on a self-regulation inventory was marginally improved. The study demonstrates the role of pre-decisional, or motivational components as contrasted with post-decisional goal enactment, and offers promise for the role of self-regulation planning and implementation intentions in assisting drivers in achieving their mobility goals and promoting safer driving across the lifespan, even in the context of unchanging beliefs such as perceived risk or driver anxiety.

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A modernkori számvitel egyik alapvető kérdése, hogy a pénzügyi beszámolás címzettjét – az érdekhordozókat – miként lehet azonosítani. Ez a törekvés már a klasszikus, azóta meghaladottá vált elméletekben is központi szerepet töltött be és modern, posztmodern elméletekben kulcsfontosságúvá vált. A tapasztalatok alapján az azonosított érdekhordozók köre módosult, bővült. Ennek a fejlődésnek a vizsgálata során a számvitel számos olyan ismérvét sikerült azonosítani, amely segítségével a vonatkozó szabályok tökéletesíthetők. Emellett az evolúció vizsgálata segítségével közvetlenül is megfigyelhetővé vált az, hogy a számvitelt extern módon szabályozó hatalom szükségessége milyen feltételek teljesítése mellett igazolható. A vizsgálat során azonosíthatóvá váltak olyan helyzetek, amikor a számviteli szabályozó és „kívülről irányított” pénzügyi beszámolás szuboptimális helyzethez vezet. A cikk az érdekhordozói elméletek fejlődését a klasszikus felfogásoktól indulva mutatja be. Feltárja, hogy a modern – jelenleg elfogadott – koalíciós vállalatfelfogás miben hozott újat, elsősorban miként hívta életre az extern szabályozót. _____ One of the key problems of the modern financial accounting is how to define the stakeholders. This problem was already a key issue in the already outdated classical stakeholder theories. Research and experience noted that the group of stakeholders has widened and has been modified. Through this evolution researchers identified many characteristics of financial reporting through which the regulation could have been improved. This advance pointed out which are the situations when the existence of an extern accounting regulator may be justified, since under given circumstances this existence led to suboptimal scenario. This paper deals with the stakeholder theories, starting with the classical ones. The article points out how did the currently accepted theory changed the assertions of the previous one and how was the external regulator created as an inevitable consequence. The paper also highlights the main issues raised by the post-modern theories; those, which try to fit the current questions into the current stakeholder models. The article also produces a Hungarian evidence for the previously mentioned suboptimal scenario, where the not tax-driven regulation proves to be suboptimal.

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This dissertation investigated the relationship between the September 11, 2001 terrorist attacks and the internationalization agenda of U.S. colleges and universities. The construct, post-9/11 syndrome, is used metaphorically to delineate the apparent state of panic and disequilibrium that followed the incident. Three research questions were investigated, with two universities in the Miami-area of South Florida, one private and the other public, as qualitative case studies. The questions are: (a) How are international student advisors and administrators across two types of institutions dealing with the post-9/11 syndrome? (b) What, if any, are the differences in international education after 9/11? (c) What have been the institutional priorities in relation to international education before and after 9/11? Data-gathering methods included interviews with international student/study abroad advisors and administrators with at least 8 years of experience in the function(s) at their institutions, document and institutional data analysis. The interviews were based on the three-part scheme developed by Schuman (1982): context of experience, details of experience and reflection on the meaning of experiences. Taped interviews, researcher insights, and member checks of transcripts constituted an audit trail for this study. Key findings included a progressive decline in Fall to Fall enrollment of international students at UM by 13.05% in the 5 years after 9/11, and by 6.15% at FIU in the seven post-9/11 years. In both institutions, there was an upsurge in interest in study abroad during the same period but less than 5% of enrolled students ventured abroad annually. I summarized the themes associated with the post-9/11 environment of international education as perceived by my participants at both institutions as 3Ms, 3Ts, and 1D: Menace of Anxiety and Fear, Menace of Insularity and Insecurity, Menace of Over-Regulation and Bigotry, Trajectory of Opportunity, Trajectory of Contradictions, Trajectory of Illusion, Fatalism and Futility, and Dominance of Technology. Based on these findings, I recommended an integrated Internationalization At Home Plus Collaborative Outreach (IAHPCO) approach to internationalization that is based on a post-9/11 recalibration of national security and international education as complementary rather than diametrically opposed concepts.

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The Sarbanes-Oxley Act represents an important watershed event in the history and regulation of the accounting profession. In this dissertation, I develop arguments as to why we can expect differences in auditor behavior before and after SOX and empirically test if indeed there were differences in auditor behavior before and after SOX. My dissertation consists of three essays. For the three essays, I investigate issues related to auditor independence, audit pricing, the impact of auditor changes in the post-SOX period. The motivation for the first part of my research comes from the SEC's assertions that there are differences between types of non-audit services in terms of their potential to adversely impact auditor independence. The first part of my dissertation empirically validates the SEC's assertions that auditors would be more conservative in those instances where the tax and other non-audit services fee ratios are high but not when the audit-related fee ratio is high. The second part of my study examines if auditors are less likely to "low ball" their audit fees in the period after SOX than in the period preceding SOX. Legislators, regulators, and the media have expressed concerns that auditors "low ball" the fees for initial year audits and that such low-balling can lead to reduced audit quality. I find that there is significant initial year audit fee discount in pre-SOX period and but the fee discount does not hold in post-SOX periods. The third part of my dissertation examines the association between auditor switches and auditor conservatism. I find that a large portion of Big 4 clients switch to non-Big 4 auditors and there is no significant evidence indicating that successor auditors are more conservative in the post-SOX period.

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Gene regulation is a complex and tightly controlled process that defines cell function in physiological and abnormal states. Programmable gene repression technologies enable loss-of-function studies for dissecting gene regulation mechanisms and represent an exciting avenue for gene therapy. Established and recently developed methods now exist to modulate gene sequence, epigenetic marks, transcriptional activity, and post-transcriptional processes, providing unprecedented genetic control over cell phenotype. Our objective was to apply and develop targeted repression technologies for regenerative medicine, genomics, and gene therapy applications. We used RNA interference to control cell cycle regulation in myogenic differentiation and enhance the proliferative capacity of tissue engineered cartilage constructs. These studies demonstrate how modulation of a single gene can be used to guide cell differentiation for regenerative medicine strategies. RNA-guided gene regulation with the CRISPR/Cas9 system has rapidly expanded the targeted repression repertoire from silencing single protein-coding genes to modulation of genes, promoters, and other distal regulatory elements. In order to facilitate its adaptation for basic research and translational applications, we demonstrated the high degree of specificity for gene targeting, gene silencing, and chromatin modification possible with Cas9 repressors. The specificity and effectiveness of RNA-guided transcriptional repressors for silencing endogenous genes are promising characteristics for mechanistic studies of gene regulation and cell phenotype. Furthermore, our results support the use of Cas9-based repressors as a platform for novel gene therapy strategies. We developed an in vivo AAV-based gene repression system for silencing endogenous genes in a mouse model. Together, these studies demonstrate the utility of gene repression tools for guiding cell phenotype and the potential of the RNA-guided CRISPR/Cas9 platform for applications such as causal studies of gene regulatory mechanisms and gene therapy.

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The six-layered neuron structure in the cerebral cortex is the foundation for human mental abilities. In the developing cerebral cortex, neural stem cells undergo proliferation and differentiate into intermediate progenitors and neurons, a process known as embryonic neurogenesis. Disrupted embryonic neurogenesis is the root cause of a wide range of neurodevelopmental disorders, including microcephaly and intellectual disabilities. Multiple layers of regulatory networks have been identified and extensively studied over the past decades to understand this complex but extremely crucial process of brain development. In recent years, post-transcriptional RNA regulation through RNA binding proteins has emerged as a critical regulatory nexus in embryonic neurogenesis. The exon junction complex (EJC) is a highly conserved RNA binding complex composed of four core proteins, Magoh, Rbm8a, Eif4a3, and Casc3. The EJC plays a major role in regulating RNA splicing, nuclear export, subcellular localization, translation, and nonsense mediated RNA decay. Human genetic studies have associated individual EJC components with various developmental disorders. We showed previously that haploinsufficiency of Magoh causes microcephaly and disrupted neural stem cell differentiation in mouse. However, it is unclear if other EJC core components are also required for embryonic neurogenesis. More importantly, the molecular mechanism through which the EJC regulates embryonic neurogenesis remains largely unknown. Here, we demonstrated with genetically modified mouse models that both Rbm8a and Eif4a3 are required for proper embryonic neurogenesis and the formation of a normal brain. Using transcriptome and proteomic analysis, we showed that the EJC posttranscriptionally regulates genes involved in the p53 pathway, splicing and translation regulation, as well as ribosomal biogenesis. This is the first in vivo evidence suggesting that the etiology of EJC associated neurodevelopmental diseases can be ribosomopathies. We also showed that, different from other EJC core components, depletion of Casc3 only led to mild neurogenesis defects in the mouse model. However, our data suggested that Casc3 is required for embryo viability, development progression, and is potentially a regulator of cardiac development. Together, data presented in this thesis suggests that the EJC is crucial for embryonic neurogenesis and that the EJC and its peripheral factors may regulate development in a tissue-specific manner.

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At the crux of health disparities for women of color lies a history of maltreatment based on racial difference from their white counterparts. It is their non-whiteness that limits their access to the ideologies of “woman” and “femininity” within dominant culture. As the result of this difference, the impact of the birth control movement varied among women based on race. This project explores how the ideology attributed to the black female body limited black women’s access to “womanhood” within dominant culture, and analyzes the manners in which their reproductive autonomy was compromised as the result of changes to that ideology through time. This project operates under the hypothesis that black women’s access to certain aspects of femininity such as domesticity and motherhood reflected their roles in slave society, that black women’s reproductive value was based on the value of black children within slave culture, and that both of these factors dictated the manner in which their reproductive autonomy was managed by health professionals. Black people’s worth as a free labor force within dominant culture diminished when the Reconstruction Amendments were added to the constitution and slavery was deemed unconstitutional—resulting in the paradigmatic shift from the promotion of black fertility to its recession. America’s transition to the medicosocial regulation of black fertility through Eugenics, the role of the black elite in the movement, and the negative impact of this agenda on the reproductive autonomy of black women from low socioeconomic backgrounds are enlisted as support. The paper goes on to draw connections between post-slavery ideology of black femininity and modern-day medicosocial occurrences within clinical settings in order to advocate for increased bias training for medical professionals as a means of combating current health disparities. It concludes with the possibility that this improvement in medical training could persuade people of color to seek out medical intervention at earlier stages of illness and obtain regular check-ups by actively countering physicians’ past transgressions against them.

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The current thesis examines memory bias for state anxiety prior to academic achievement situations like writing an exam and giving a speech. The thesis relies on the reconstruction principle, which assumes that memories for past emotions are reconstructed rather than stored permanently and accurately. This makes them prone to memory bias, which is af-fected by several influencing factors. A major aim is to include four important influencing factors simultaneously. Early research on mood and emotional autobiographical memory found evidence for the existence of a propositional associative network (Bower, 1981; Col-lins & Loftus, 1975), leading to mood congruent recall. But empirical findings gave also strong evidence for the existence of mood incongruent recall for one’s own emotions, which was for example linked to mood regulation via mood repair (e.g. Clark & Isen, 1982), which seems to be associated to the personality traits extraversion and neuroticism (Lischetzke & Eid, 2006; Ng & Diener, 2009). Moreover, neuroticism and trait anxiety are related to rumination, which is seen as negative post-event-processing (e.g. Wells & Clark, 1997). Overall, the elapsed time since the emotional event happened should have an impact on recall of emotions. Following the affect infusion model by Robinson and Clore (2002a), the influence of personality on memory bias should increase over time. Therefore, three longitudinal studies were realized, using naturally occurring as well as laboratory settings. The used paradigm was equivalent in all studies. Subjects were asked about their actual state anxiety prior to an academic achievement situation. Directly after the situation, cur-rent mood and recall of former anxiety were assessed. The same procedure was repeated a few weeks later. Personality traits and post-event-processing were also assessed. The results suggest a need to have a differentiated view on predicting memory bias. Study 1 (N = 131) as well as study 3 (N = 53) found evidence for mood incongruent memory in the sense of mood repair and downward regulation as a function of personality. Rumination was found to cause stable overestimation of pre-event anxiety in study 2 (N = 141) as well as in study 3. Although the relevance of the influencing factors changed over time, an increasing relevance of personality could not consistently be observed. The tremendously different effects of the laboratory study 2 indicated that such settings are not appropriate to study current issues. Theoretical and psychotherapeutically relevant conclusions are drawn and several limitations are discussed.

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Monocarboxylate Transporter 2 (MCT2) is a major pyruvate transporter encoded by the SLC16A7 gene. Recent studies pointed to a consistent overexpression of MCT2 in prostate cancer (PCa) suggesting MCT2 as a putative biomarker and molecular target. Despite the importance of this observation the mechanisms involved in MCT2 regulation are unknown. Through an integrative analysis we have discovered that selective demethylation of an internal SLC16A7/MCT2 promoter is a recurrent event in independent PCa cohorts. This demethylation is associated with expression of isoforms differing only in 5'-UTR translational control motifs, providing one contributing mechanism for MCT2 protein overexpression in PCa. Genes co-expressed with SLC16A7/MCT2 also clustered in oncogenic-related pathways and effectors of these signalling pathways were found to bind at the SLC16A7/MCT2 gene locus. Finally, MCT2 knock-down attenuated the growth of PCa cells. The present study unveils an unexpected epigenetic regulation of SLC16A7/MCT2 isoforms and identifies a link between SLC16A7/MCT2, Androgen Receptor (AR), ETS-related gene (ERG) and other oncogenic pathways in PCa. These results underscore the importance of combining data from epigenetic, transcriptomic and protein level changes to allow more comprehensive insights into the mechanisms underlying protein expression, that in our case provide additional weight to MCT2 as a candidate biomarker and molecular target in PCa.

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International audience

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Background. It has been reported that the histone deacetylase inhibitor (iHDAc) trichostatin A (TSA) induces an increase in MDR1 gene transcription (ABCB1). This result would compromise the use of iHDACs in combination with other cytotoxic agents that are substrates of P-glycoprotein (Pgp). It has also been reported the use of alternative promoters by the ABCB1 gene and the existence of a traslational control of Pgp protein. Finally, the ABCB1 gene is located in a genetic locus with the nested gene RUNDC3B in the complementary DNA strand, raising the possibility that RUNDC3B expression could interfere with ABCB1 alternative promoter regulation. Methods. A combination of RT-PCR, real time RT-PCR, Western blot and drug accumulation assays by flow cytometry have been used in this study. Results. The iHDACs-induced increase in MDR1 mRNA levels is not followed by a subsequent increase in Pgp protein levels or activity in several pancreatic and colon carcinoma cell lines, suggesting a traslational control of Pgp in these cell lines. In addition, the MDR1 mRNA produced in these cell lines is shorter in its 5' end that the Pgp mRNA produced in cell lines expressing Pgp protein. The different size of the Pgp mRNA is due to the use of alternative promoters. We also demonstrate that these promoters are differentially regulated by TSA. The translational blockade of Pgp mRNA in the pancreatic carcinoma cell lines could be related to alterations in the 5' end of the MDR1 mRNA in the Pgp protein expressing cell lines. In addition, we demonstrate that the ABCB1 nested gene RUNDC3B expression although upregulated by TSA is independent of the ABCB1 alternative promoter used. Conclusions. The results show that the increase in MDR1 mRNA expression after iHDACs treatment is clinically irrelevant since this mRNA does not render an active Pgp protein, at least in colon and pancreatic cancer cell lines. Furthermore, we have demonstrated that TSA in fact, differentially regulates both ABCB1 promoters, downregulating the upstream promoter that is responsible for active P-glycoprotein expression. These results suggest that iHDACs such as TSA may in fact potentiate the effects of antitumoral drugs that are substrates of Pgp. Finally, we have also demonstrate that TSA upregulates RUNDC3B mRNA independently of the ABCB1 promoter in use.