Regulation of gene-specific nuclear NF-kappaB functions by cofactors and posttranslational modifications

转录因子NF-kappaB在应激诱导的基因调控中起着核心作用。介导NF-kappaB活化的胞质事件的鉴定正在迅速进展，而这种转录因子在细胞核中的基因特异性功能却知之甚少。在我们的初步工作中，我们确定了新的核辅因子（CDK6和TRIP6）以及NF-kappaB p65的几种翻译后修饰的功能和调控。这之前的工作形成了一个分两部分的研究计划的基础，旨在阐明NF-kappaB更详细的核功能。第一部分将研究介导CDK6和TRIP6基因调控功能的机制和信号通路。我们还将研究TRIP6磷酸化在糖皮质激素介导的nf - kappab依赖性基因表达抑制中的作用。全基因组分析将阐明CDK6是否专门向NF-kappaB传递细胞周期特异性信号，或者该激酶是否与广泛的NF-kappaB激活刺激普遍相关。第二部分将研究翻译后修饰的NF-kappaB p65和dna结合突变体的全基因组募集，以研究它们在转录激活和染色质关联方面的生理功能。我们还将使用最近鉴定的构象特异性抗体研究刺激诱导的NF-kappaB p65构象开关的功能后果。这些实验将得出翻译后修饰、上下文特异性构象和dna结合对p65功能的重要性的结论。两位申请人的重叠和互补的专业知识将大大提高对健康和病变细胞中nf - kappab依赖性基因调控可塑性的分子机制的理解。

The transcription factor NF-kappaB plays a central role for stress-induced gene regulation. The identification of the cytosolic events mediating NF-kappaB activation is rapidly progressing, whereas the gene-specific functions of this transcription factor in the nucleus are poorly understood. In our preliminary work we identified novel nuclear cofactors (CDK6 and TRIP6) and the function and regulation of several postranslational modifications of NF-kappaB p65. This preceding work forms the basis for a bipartite research program that aims to elucidate the nuclear functions of NF-kappaB in much more detail. The first part will investigate the mechanisms and signaling pathways mediating the gene regulatory functions of CDK6 and TRIP6. We will also investigate the contribution of TRIP6 phosphorylation for its function in glucocorticoid-mediated repression of NF-kappaB-dependent gene expression. Genome-wide analyses will clarify whether CDK6 is specialized to communicate cell cycle-specific signals to NF-kappaB or whether this kinase is of general relevance for a broad range of NF-kappaB activating stimuli. The second part will investigate the genome-wide recruitment of posttranslationally modified NF-kappaB p65 and a DNA-binding mutant to investigate their physiological function for transcriptional activation and chromatin association. We will also investigate the functional consequences of a stimulus-induced conformational switch of NF-kappaB p65 using a recently identified conformation-specific antibody. These experiments will allow conclusions on the significance of posttranslational modifications, context-specific conformation and DNA-binding for p65 functions. The overlapping and complementary expertise of both applicants will allow a significantly improved understanding of the molecular mechanisms underlying the plasticity of NF-kappaB-dependent gene regulation in healthy and diseased cells.