Mechanisms and functions of lysine methylation of promoter-bound NFkB and STAT3

响应于激活信号，NF κ B和STATS在特异性赖氨酸残基上可逆地甲基化， 染色质重塑酶，以深刻影响其功能的方式。我们建议， 甲基化与组蛋白甲基化一起发生，当这些因子与特定的启动子结合时， 改变诱导基因表达的强度和持续时间，使依赖性生物学特性具有可塑性， 反应，并帮助解释不同的促炎信号的具体反应。目标1。我们将 在表达STATS或NF κ B的p65亚基的细胞中进行全局基因表达分析，其中 赖氨酸甲基化位点已经突变，并且还将评估NF κ B（IL-6）的不同活化剂是否 相对于TNF相对于TLR）在p65上施加不同的磷酸化模式作为“条形码”， 影响靶基因的不同群组的赖氨酸甲基化模式。目标2.我们将延长初始 观察到甲基化作用发生在启动子结合的STATS和NF κ B上，作为有序的 导致转录激活的事件序列。染色质将被广泛使用 免疫沉淀（CHIP）测定以确定在特异性启动子处的事件的时间过程，所述特异性启动子 由STATS或p65的赖氨酸甲基化差异调节。我们还将使用创新的质量 光谱方法来鉴定组装在特定启动子上的未知蛋白质， STATS或NF κ B激活后的时间。目标3：对于不直接接触 DNA，甲基化可能有助于改变功能的辅助蛋白的结合。这些蛋白质将 通过使用GST蛋白结构域微阵列和通过免疫沉淀测定来鉴定。K218和K221 p65确实与DNA接触，因此我们将通过研究纯甲基化的p65与DNA的结合来探索这些相互作用。 蛋白质直接转化为DNA目标4。IRFS、TIS 7和IRAK 4是NF κ B活化的重要调节剂， 功能。我们将确定每一个如何影响p65的磷酸化和甲基化，以及依赖于p65的磷酸化和甲基化。 NpKB依赖性基因表达模式。其激活被调节的基因的例子将 如上文所述进行详细研究，以确定启动子特异性机制。在项目1、3和4中， 也将在原代小鼠细胞中研究NF κ B对这些基因的激活， 小鼠肿瘤模型。通过这种方式，项目2的机制分析将直接连接到生物 其他三个项目的分析。 相关性（参见说明）： 最近的证据表明，启动子结合的转录因子被相同的酶修饰 修饰组蛋白，具有重要的功能性后果。这些修改是基因特异性的， 了解它们如何发生，以及它们如何影响对主要促炎细胞因子的反应 (IL-1，IL-6，TNF，TLR）通过其NF κ B和STATS的活化，对于充分理解如何 免疫系统细胞与上皮细胞的相互作用导致癌症。

In response to activating signals, NFKB and STATS are reversibly methylated on specific lysine residues by chromatin remodeling enzymes, in ways that profoundly affect their functions. We propose that reversible methylation occurs, in concert with histone methylation, when the factors are bound to specific promoters, altering the strength and duration of inducible gene expression, giving plasticity to the dependent biological responses, and helping to explain specific responses to different pro-inflammatory signals. Aim 1. We will conduct global gene expression analyses in cells expressing STATS or the p65 subunit of NFKB in which the lysine methylation sites have been mutated and will also evaluate whether different activators of NFKB (IL-6 versus TNF versus TLRs) impose different patterns of phosphorylation on p65 as "bar codes" that in turn affect lysine methylation patterns at different cohorts of target genes. Aim 2. We will extend initial observations that methylafions take place on promoter-bound STATS and NFKB as part of an ordered sequence of events leading to transcriptional activation. Extensive use will be made of chromatin immunoprecipitation (CHIP) assays to determine the fime courses of events at specific promoters that are regulated differentially by lysine methylation of STATS or p65. We also will use innovative mass spectrometric approaches to identify unknown proteins that assemble on specific promoters as a function of time following activation of STATS or NFKB. Aim 3. For lysine residues that are not in direct contact with DNA, methylation may facilitate the binding of accessory proteins that alter function. These proteins will be identified by using a GST protein domain microarray and by immunopreciptation assays. K218 and K221 of p65 do contact DNA, so we will explore these interactions by studying the binding of the pure methylated protein to DNA directly. Aim 4. IRFS, TIS7 and IRAK4 are important modulators of NFKB activafion and funcfion. We will determine how each affects the phosphorylation and methylation of p65 and the dependent patterns of NpKB-dependent gene expression. Examples of genes whose activafion is modulated will then be studied in detail as above, to define promoter-specific mechanisms. In Projects 1, 3 and 4, the ways in which the activation of these genes by NFKB is modulated will also be studied in primary mouse cells and in mouse tumor models. In this way, the mechanistic analyses of Project 2 will connect directly to the biological analyses of the other three projects. RELEVANCE (See instructions): Recent evidence has shown us that promoter-bound transcription factors are modified by the same enzymes that modify histones, with important functional consequences. The modifications are gene-specific, and a full understanding of how they occur, and of how they affect the responses to major pro-inflammatory cytokines (IL-1, IL-6, TNF, TLRs) through their activation of NFKB and STATS, is important for understanding fully how the interactions of cells of the immune system with epithelial cells lead to cancer.