Mechanisms of Compartmentalized cAMP Signaling

描述（由申请人提供）：通过环腺苷酸（cAMP）及其效应分子（如cAMP依赖性蛋白激酶（PKA）和cAMP激活的交换蛋白（Epac））进行信号传导，调节多种细胞功能，包括细胞生长、增殖、代谢、存活和移动性，以及胰腺癌情况下的胰岛素分泌。细胞我们的研究的总体目标是阐明时空区室化在实现cAMP信号转导的高度特异性中的分子机制和功能作用。cAMP信号通路的异常对肥胖和2型糖尿病等临床疾病有影响，特别是在？细胞功能。对cAMP信号传导特异性的机制理解对于开发这些临床病症的治疗策略至关重要。cAMP效应的空间区室化的概念是在20年前提出的，但只有在最近几年才有创新的方法来研究细胞环境中的cAMP信号传导，以提供直接的机制证据。然而，尽管这些最新的进展，仍然有很大的差距，在我们的理解有关的时空调节cAMP及其效应器的机制。此外，很少有人知道如何编码的信号信息的时空模式的活动被翻译成特定的功能反应。在我们的初步研究中，我们已经开发了用于监测Epac作用的荧光生物传感器，用于跟踪多种信号传导活动的共成像方法和用于在亚细胞位置酶促操纵cAMP水平的方法。此外，我们最近的研究发现，在MIN 6？细胞在本研究中，我们将在这些初步发现的基础上，围绕这些具体目标来验证我们的中心假设，即cAMP，PKA和Epac的活性是时空区隔的，以特异性地调节该途径的功能效应：1）进一步开发测量cAMP，PKA和Epac动力学的分子工具; 2）阐明MIN 6 B细胞振荡回路的调控机制和功能作用。 公共卫生相关性：通过cAMP的信号传导调节多种细胞功能，如细胞生长、增殖、代谢、存活和移动性，以及胰腺癌中的胰岛素分泌。细胞这一通路的异常对肥胖和II型糖尿病等临床疾病有影响，特别是在？细胞功能。我们研究的总体目标是更好地理解这种无处不在的信号分子如何以高信号特异性调节许多不同的功能。这样的理解是至关重要的发展治疗策略的临床条件所产生的失调cAMP信号。

DESCRIPTION (provided by applicant): Signaling through cyclic AMP (cAMP) and its effector molecules, such as cAMP-dependent protein kinase (PKA) and exchange proteins activated by cAMP (Epac), regulates a variety of cellular functions including cell growth, proliferation, metabolism, survival and mobility, as well as insulin secretion in the case of pancreatic ? cells. The overall goal of our research is to elucidate the molecular mechanisms and functional roles of spatiotemporal compartmentalization in achieving high specificity in cAMP signaling. Aberrations in the cAMP signaling pathway have implications for clinical conditions such as obesity and type 2 diabetes mellitus, particularly in the context of ?-cell functions. A mechanistic understanding of cAMP signaling specificity is crucial to developing therapeutic strategies for these clinical conditions. The concept of spatial compartmentalization of cAMP effects was proposed 20 years ago, but only in recent years have innovative approaches to studying cAMP signaling in the cellular context become available to provide direct mechanistic evidence. However, despite these recent advances, there are still large gaps in our understanding about the mechanisms underlying the spatiotemporal regulation of cAMP and its effectors. Furthermore, little is known about how the signaling information encoded in the spatiotemporal patterns of activities is translated into specific functional responses. In our preliminary studies, we have developed fluorescent biosensors for monitoring Epac action, co-imaging approaches for tracking multiple signaling activities and a method for enzymatic manipulation of cAMP levels at subcellular locations. Furthermore, our recent studies have discovered an oscillatory circuit that consists of cAMP, PKA and Ca2+ in MIN6 ? cells. In the current proposal, building upon these preliminary findings, we will focus on these specific aims to test our central hypothesis that the activities of cAMP, PKA and Epac are spatiotemporally compartmentalized to specifically regulate functional effects of this pathway: 1) further develop molecular tools for measuring cAMP, PKA and Epac dynamics; 2) elucidate the regulatory mechanisms and functional roles of the oscillatory circuit in MIN6 b cells. PUBLIC HEALTH RELEVANCE: Signaling through cAMP regulates a variety of cellular functions such as cell growth, proliferation, metabolism, survival and mobility, as well as insulin secretion in the case of pancreatic ??cells. Aberrations in this pathway have implications for clinical conditions such as obesity and type II diabetes mellitus, particularly in the context of ?-cell functions. The overall goal of our research is to achieve a better mechanistic understanding about how this ubiquitous signaling molecule regulates many diverse functions with high signaling specificity. Such an understanding is crucial to developing therapeutic strategies for clinical conditions arising from dysregulated cAMP signaling.