Regulation of CBP by Synaptic Activity

描述(由申请人提供)： 活性调节的基因表达在这两个过程中起着基础性的作用 突触回路重塑与神经元存活。依赖于活动 细胞内钙的增加触发数百或可能的表达 成千上万的基因。CAMP反应元件(CRE)被认为是一种主要的 即刻早期基因(IEGs)启动子分析中的CA2反应元件 而且许多(如果不是大多数的话)钙反应启动子都含有Cres。碱性亮氨酸 拉链转录因子CREB以二聚体的形式与Cre结合，可以 由钙、cAMP/PKA和生长因子信号通路激活。这个 转录因子CREB是活性诱导的钙内流的主要靶点 是神经元存活和适应性突触可塑性的关键调节因子。 然而，钙激活CREB的机制尚不清楚。 已澄清。已经证实，PKA使CREB的Ser 133磷酸化，并且 创建一个磷酸-丝氨酸对接基序，招募其辅活化子CBP(或 同源基因，P300)。CBP的招募被认为可以提高转录 通过它与一般转录因子的关联来激活 机械或通过其固有的组蛋白乙酰转移酶活性。虽然 人们普遍认为，活动诱导的钙内流调节CREB功能。 类似地，促进CBP招募和 转录激活还没有明确的定义。 这项建议的一个主要主题是确定PKA-CREB-CBP 范式也与钙激活的转录有关。因此，最初的目标是 这项研究的重点将是确定神经元活动是否会诱导 招聘CBP到CREB，以及是否需要招聘CBP 转录激活。提出了四个具体目标。(一)确定 突触活动是否诱导CBP在神经元和CREB中的募集 CBP的招募是否足以完全转录激活。 (2)破译活动调节的信号级联，促进 CREB和CBP的磷酸化和活化。(3)确定突触如何 活性和钙内流调节CBP功能。(4)分析我国的监管现状。 CBP和CREB在CaM激酶IV缺陷小鼠中的功能。 剖析导致突触活动的生化事件 CREB的磷酸化、CBP的募集和CBP依赖的“激活” 抄写。深入了解活动调节的机制 转录在神经退行性病变的治疗中具有相关性 这可能是由于兴奋性毒性细胞死亡或凋亡所致。通过受指导者 职业发展计划，首席调查员将获得 在分子神经生物学领域的生产能力，重点是 关于基因调控的。这将通过执行上述操作来实现 在地方和国家研讨会和会议上进行研究、出席和介绍， 并参加分子生物学和神经生理学的课程教学 技巧。

DESCRIPTION (provided by applicant): Activity-regulated gene expression plays a fundamental role in both the remodeling of synaptic circuitry and in neuronal survival. Activity-dependent increases in intracellular Ca2+ trigger the expression of hundreds or perhaps thousands of genes. The cAMP response element (CRE) was identified as a major Ca2+ responsive element via analysis of immediate early gene (IEGs) promoters and many if not most Ca2+ responsive promoters contain CREs. The basic leucine zipper transcription factor, CREB, binds to the CRE as a dimer and can be activated by Ca2+, cAMP/PKA, and growth factor signaling pathways. The transcription factor CREB is a major target of activity-induced Ca2+ influx and is a key regulator of both neuronal survival and adaptive synaptic plasticity. Nevertheless, the mechanisms by which Ca2+ activates CREB have not been clearly elucidated. It is well established that PKA phosphorylates Ser 133 of CREB and creates a phospho-serine docking motif that recruits its coactivator CBP (or the homologue, p300). Recruitment of CBP is thought to enhance transcriptional activation either via its association with the general transcriptional machinery or via its intrinsic histone acetyltransferase activity. Although activity-induced Ca2+ influx is widely believed to regulate CREB function in an analogous manner, the signaling cascades that promote CBP recruitment and transcriptional activation have not been clearly defined. A major theme of this proposal is to determine whether the PKA-CREB-CBP paradigm also pertains to Ca2+-activated transcription. Thus, an initial goal of this study will be to determine whether neuronal activity induces the recruitment of CBP to CREB and whether CBP recruitment is required for transcriptional activation. Four specific aims are proposed. (1) Determine whether synaptic activity induces the recruitment of CBP to CREB in neurons and whether recruitment of CBP is sufficient for full transcriptional activation. (2) Decipher the activity-regulated signaling cascades that promote the phosphorylation and activation of CREB and CBP. (3) Determine how synaptic activity and Ca2+ influx regulate CBP function. (4) Analyze the regulation of CBP and CREB function in mice deficient for CaM kinase IV. This study seeks to dissect the biochemical events result in synaptic activity-mediated phosphorylation of CREB, recruitment of CBP, and "activation" of CBP-dependent transcription. Gaining insight into the mechanisms of activity-mediated transcription has relevance in the treatment of neurodegenerative pathologies that may result from excitotoxic cell death or apoptosis. Through a mentored career development plan, the Principal Investigator will gain an enhanced capacity to be productive in the field of molecular neurobiology with a focus on gene regulation. This will be accomplished by conducting the above described research, attending and presenting at local and national seminars and meetings, and participating in courses teaching molecular biology and neurophysiology techniques.