MHC Class II Transactivator Function & Regulation

描述（由申请人提供）：MHC II类反式激活因子（CIITA）是一种 调节重要基因表达的关键转录因子 免疫反应和建立正常的免疫稳态 控制主机。CIITA激活抗原相关基因的表达 但抑制Th 2型细胞因子和FasL的表达。我们和 其他人已经证明，CIITA作为活化剂和 阻遏物是由CIITA与组蛋白乙酰转移酶相互作用介导的 CBP/p300。最近，我们和其他人也观察到CIITA形成了一种复合物， self. CIITA突变体自身结合缺陷不能激活MHC II类启动子，表明自我缔合的能力与 CIITA的反式激活潜力。因此，了解CIITA活动如何 是由多种相互作用调节的， CIITA如何调节免疫反应。 在当前的应用中，我们提出了具有总体目标的实验 了解CIITA的结构和功能，以调节目标 基因表达。首先，分子间和分子内 CIITA的交互受到控制，该信息用于激活CIITA 作为转录调节因子的功能，将通过遗传， 生物化学和分子生物学方法。第二， 细胞保留活性和/或非活性形式的CIITA蛋白，并响应于 将研究通过磷酸化调节CIITA活性信号。 第三，我们将研究CIITA的相互作用，在活细胞中使用荧光 共振能量转移本申请中描述的实验将 深入了解CIITA如何感知和响应发生的刺激 在免疫反应和疾病状态期间，以维持细胞调节。

DESCRIPTION (provided by applicant): MHC class II transactivator (CIITA) is a critical transcription factor regulating the expression of genes that are vital to immune responses and for the establishment of normal immune homeostatic controls of a host. CIITA activates the expression of genes involved in antigen presentation but represses the expression of Th2 type cytokine and FasL. We and others have demonstrated that the activity of CIITA as an activator and a repressor is mediated by CIITA interaction with histone acetyltransferase CBP/p300. Recently, we and others also observed that CIITA forms a complex with self. CIITA mutants defective in self-association failed to activate the MHC class II promoter suggesting that the ability of self-association is linked to transactivation potential of CIITA. Therefore, understanding how CIITA activity is regulated by multiple interactions has great relevance towards understanding how immune response is modulated by CIITA. In the current application, we propose experiments with the overall objective of understanding the structure and function of CIITA to regulate the target gene expression. First, the mechanisms by which inter- and intra molecular interaction of CIITA is controlled and this information to activate CIITA function as a transcriptional regulator, will be explored through genetic, biochemical and molecular biology approaches. Secondly, the mechanisms whereby cells retain CIITA protein in an active and/or inactive form and respond to a signal to regulate CIITA activity by phosphorylation, will be investigated. Thirdly, we will examine CIITA interaction in living cells using fluorescence resonance energy transfer. The experiments described in this application will provide insight into how CIITA senses and responds to stimulus that occur during immune response, and disease states, to maintain cellular regulation.