AP-1 Complexes and Target Gene Regulation

描述（由申请人提供）：细胞内信号传导在由转录因子（如激活蛋白-1（AP-1））介导的基因表达变化中达到高潮。AP-1是一种广泛表达的转录复合物，由二聚化碱性亮氨酸拉链（bZIP）蛋白组成。AP-1在细胞生长、分化、存活和凋亡中起作用，并且失调的AP-1活性在从癌症到神经退行性疾病的人类疾病中占突出地位。转录因子是治疗干预的主要靶点，设计用于调节AP-1活性的体内策略在许多临床情况下将是一个重大进展。BATF和高度相关的JDP 1蛋白是独特的AP-1家族成员，与AP-1的中心组分Jun蛋白二聚化并抑制AP-1活性。本申请的目的是确定这些AP-1抑制剂在体内的作用，并检验这些作用与特定AP-1靶基因的调节有关的假设。在目标1中，将使用在内源水平表达表位标记的BATF和JDP 1的基因工程小鼠模型来定义这些蛋白质的精确表达模式，并使用染色质免疫沉淀（ChIP）结合新型AP-1启动子微阵列的筛选来鉴定BATF直接结合的基因。将使用BATF无效、JDP 1无效和双无效小鼠评估这些蛋白介导的AP-1抑制的丧失如何影响发育，并分析表征BATF无效表型的基因表达变化的全谱。目标2将使用质谱分析来识别和量化调节BATF的DNA结合和二聚化特性并影响其作为AP-1抑制剂的功效的离散磷酸化事件。最后，在目标3中，M1细胞系统将用于通过遵循BATF介导的靶基因调节和通过将BATF定位在控制这些细胞分化的信号传导网络内来进一步研究BATF的功能。这些研究的短期目标是建立BATF和JDP 1在体内的功能，并将产生必要的信息，以解决我们使用这些AP-1抑制剂进行转录靶向治疗的长期目标。 相关性：作为许多人类疾病特征的异常细胞生长通常与由蛋白质如转录因子的AP-1家族介导的基因表达失调有关。BATF和JDP 1被鉴定为AP-1家族成员，负调控基因表达。这项研究的目的是充分表征这些蛋白质的生物活性，作为建立其在AP-1靶向治疗中的效用的第一步。

DESCRIPTION (provided by applicant): Intracellular signaling culminates in gene expression changes that are mediated by transcription factors such as activator protein-1 (AP-1). AP-1 is a widely expressed transcription complex consisting of dimerizing basic leucine zipper (bZIP) proteins. AP-1 functions in cell growth, differentiation, survival and apoptosis, and deregulated AP-1 activity figures prominently in human diseases from cancer to neurodegenerative disorders. Transcription factors are major targets for therapeutic intervention, and in vivo strategies designed to modulate AP-1 activity would be a significant advance in many clinical situations. BATF, and the highly related JDP1 protein, are unique AP-1 family members that dimerize with the central components of AP-1 - the Jun proteins - and inhibit AP-1 activity. The objective of this application is to define the roles of these AP-1 inhibitors in vivo and to test the hypothesis that these roles are linked to the regulation of specific AP-1 target genes. In Aim 1, genetically engineered mouse models expressing epitope-tagged BATF and JDP1 at endogenous levels will be used for defining the precise expression patterns of these proteins and for identifying genes directly bound by BATF using chromatin immunoprecipitation (ChIP) coupled with the screening of novel AP-1 promoter microarrays. BATF null, JDP1 null and double null mice will be used to assess how the loss of AP-1 inhibition mediated by these proteins affects development and to profile the full spectrum of gene expresson changes that characterize the BATF null phenotype. Aim 2 will use mass spectral analysis to identify and quantify discreet phosphorylation events that regulate the DNA binding and dimerization properties of BATF and influence its efficacy as an AP-1 inhibitor. Lastly, in Aim 3, the M1 cell system will be used to further investigate the function of BATF by following BATF-mediated regulation of target genes and by positioning BATF within the signaling network that controls the differentiation of these cells. These studies have the short-term goal of establishing the function of BATF and JDP1 in vivo and will generate the information necessary to address our long-term goals of using these AP-1 inhibitors for transcription-targeted therapies. Relevance: The aberrant cell growth that is a feature of many human diseases often is linked to deregulated gene expression mediated by proteins such as the AP-1 family of transcription factors. BATF and JDP1 have been identified as AP-1 family members that negatively regulate gene expression. The goal of this research is to fully characterize the biological activities of these proteins as a first step towards establishing their utility in AP-1 targeted therapies.