Structure-function relationship of NFkB p65

NFkB p65 的结构-功能关系

• 批准号: 7963969
• 负责人: Dan Longo
• 金额: $ 35.78万
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7963969
• 关键词: Aging; Antibodies; Architecture; Binding; Cells; Chromatin; Development; Enzymes; Family; Fibroblasts; Gene Expression; Genes; Histones; Immune System and Related Disorders; Immune system; Inflammation; Malignant Neoplasms; Mediating; Mus; Nuclear Translocation; Pathway interactions; Phosphorylation; Phosphorylation Site; Play; Post-Translational Protein Processing; Receptor Signaling; Recruitment Activity; Regulation; Role; Serine; Signal Transduction; Site; Structure-Activity Relationship; Transcription Initiation Site; Transcriptional Activation; cis acting element; interest; lymphotoxin beta receptor; member; p65; promoter; transcription factor

We have previously demonstrated that the phosphorylation of p65 at serine 536 was differentially recruited to selective promoters following cell activation. We have recently demonstrated that the distance between the site of p65 binding and the transcription start site of a particular gene determines if p65 needs to be phosphorylated on serine 536. The phosphorylation of p65 was not involved in the formation of an enhanceosome, where the recruitment of histone modifying enzymes to proximal promoters was required. These findings suggested that the phosphorylation of p65 and the cis-acting elements of the promoter regulate the various NFkB responsive genes. We are currently investigating the role of various phosphorylation sites of p65 in controling the chromatin architecture surrounding p65 responsive genes. We are also examining how the various IkB members regulate the nuclear translocation of phosphorylated p65. In addition to serine 536, the phosphorylation of serine 529 of p65 has been shown to regulate transcriptional activity. We are currently investigating the relationship between the phosphorylation of serines 529 and 536 in regulating the chromatin architecture. We have shown previously that the phosphorylation of p65 at serine 536 resulted in an increase in Csf2 gene expression. Recently, it has been shown that the phosphorylation of p65 at serine 536 by IKKa was induced by lymphotoxin-beta receptor (LTbR) signaling in mouse fibroblast. We have observed that the treatment of 3T3 fibroblast cells with agonistic anti-LTbR antibody resulted in the phosphorylation of p65 at serine 536, but no expression of Csf2 gene. However, priming with anti-LTbR antibody resulted in a synergistic increase of TNF-mediated Csf2 expression. The synergistic enhancement required the activation of NIK and signaling through the alternative NFkB pathway. Furthermore, the nuclear translocation and recruitment of both p65 and RelB to the Csf2 promoter were observed during the LTbR priming of TNF-mediated Csf2 gene expression. We are currently examining the mechanism of priming.

我们之前已经证明，p65 在丝氨酸 536 处的磷酸化在细胞激活后被差异性地招募到选择性启动子。 我们最近证明，p65 结合位点与特定基因的转录起始位点之间的距离决定了 p65 是否需要在丝氨酸 536 上磷酸化。p65 的磷酸化不参与增强小体的形成，其中招募需要对近端启动子进行组蛋白修饰酶。 这些发现表明 p65 的磷酸化和启动子的顺式作用元件调节各种 NFkB 反应基因。 我们目前正在研究 p65 的各种磷酸化位点在控制 p65 响应基因周围的染色质结构中的作用。 我们还在研究各种 IkB 成员如何调节磷酸化 p65 的核转位。除了丝氨酸 536 之外，p65 丝氨酸 529 的磷酸化已被证明可以调节转录活性。 我们目前正在研究丝氨酸 529 和 536 的磷酸化在调节染色质结构中的关系。 我们之前已经表明，p65 丝氨酸 536 处的磷酸化导致 Csf2 基因表达增加。最近，研究表明 IKKa 对 p65 丝氨酸 536 的磷酸化是由小鼠成纤维细胞中淋巴毒素-β 受体 (LTbR) 信号传导诱导的。 我们观察到用激动性抗LTbR抗体处理3T3成纤维细胞导致p65丝氨酸536处磷酸化，但Csf2基因不表达。 然而，用抗 LTbR 抗体引发导致 TNF 介导的 Csf2 表达协同增加。协同增强需要通过替代 NFkB 途径激活 NIK 和信号传导。此外，在 TNF 介导的 Csf2 基因表达的 LTbR 启动过程中，观察到 p65 和 RelB 的核易位和招募到 Csf2 启动子。我们目前正在研究启动机制。