Mechanisms of Compartmentalized cAMP Signaling

项目概要： 通过环腺苷酸（cAMP）及其效应分子（如cAMP依赖性蛋白）进行信号传导 激酶（PKA）和cAMP激活的交换蛋白（Epac）调节多种细胞 功能包括细胞生长、增殖、代谢、存活和移动，以及胰岛素 在胰腺癌细胞的情况下分泌。我们研究的总体目标是阐明 实现高度特异性的时空调控的分子机制和功能作用 在cAMP信号传导中。cAMP信号通路的异常对临床状况有影响 例如肥胖症和2型糖尿病，特别是在β-细胞功能方面。一 对cAMP信号传导特异性的机制理解对于开发治疗策略至关重要 这些临床条件。 cAMP效应的空间区室化概念在20年前就提出了，但仅 近年来，在细胞环境中研究cAMP信号传导的创新方法已经成为 可提供直接的机械证据。然而，尽管最近取得了这些进展， 我们对时空调控机制的理解仍然存在很大的差距 cAMP及其效应物。此外，很少有人知道信令信息是如何编码在 活动的时空模式被转化为特定的功能反应。 在我们的初步研究中，我们开发了新的分子工具来监测和干扰 cAMP/PKA活性，进一步提高时空分辨率和精度。 此外，基于我们最近在MIN 6细胞中发现的Ca 2 +-cAMP-PKA振荡回路， 我们发现A-激酶转运蛋白79/150（AKAP 79/150）组装了一个含有PKA的 在这些细胞中的信号复合物和影响的Ca 2 +-cAMP-PKA电路的活动动力学。在 目前的建议，利用我们新的分子工具，并结合计算建模和 实验方法，我们将测试我们的假设，即Ca 2 +-cAMP-PKA振荡电路， PKA在空间和时间上被AKAP进一步调节，使PKA具有高信号特异性， 和通过频率调制的分集。具体目标是：1）开发新的分子 在活细胞中询问cAMP/PKA信号传导的时空调节的工具; 2）阐明 Ca ~（2+）-cAMP-PKA振荡回路的空间区室化和频率控制。

Project summary: 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 regulation 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 new molecular tools to monitor and perturb cAMP/PKA activities in living cells with further enhanced spatiotemporal resolution and precision. Furthermore, building on our recent discovery of a Ca2+-cAMP-PKA oscillatory circuit in MIN6  cells, we showed that A-Kinase Anchoring Protein 79/150 (AKAP79/150) assembles a PKA-containing signaling complex in these cells and influences the activity dynamics of the Ca2+-cAMP-PKA circuit. In the current proposal, utilizing our new molecular tools and by combining computational modeling and experimental approaches, we will test our hypothesis that the Ca2+-cAMP-PKA oscillatory circuit, further regulated spatially and temporally by AKAPs, allows PKA to achieve high signaling specificity and diversity through frequency modulation. The specific aims are: 1) developing novel molecular tools to interrogate the spatiotemporal regulation of cAMP/PKA signaling in living cells; 2) elucidating the spatial compartmentalization and frequency control of the Ca2+-cAMP-PKA oscillatory circuit.