CYTOSKELETAL SIGNALING THROUGH CAP PROTEINS IN YEAST

这篇文章的目标是理解信号通路是如何调用 肌动蛋白细胞骨架的变化。许多疾病过程是 与细胞骨架改变有关。当细胞被转化的时候~ 进入肿瘤细胞后，肌动蛋白在细胞骨架中重排增多 并促成允许肿瘤细胞侵袭的变化 周围的组织。肌动蛋白在以下情况下也会发生快速聚合 血小板聚集在一起。聚集，这有助于减少渗漏 来自胆管的，有时会限制血液流动，导致 中风和心脏病发作。理解肌动蛋白的调节 细胞骨架可能为它的重组提供洞察 导致许多重要疾病的进展。 许多细胞骨架的变化是通过协调调节的 Ras、Rac、Rho和Rho等几种小G蛋白的作用 Cdc42。在萌芽酵母中，酿酒酵母的同源物 RAS癌基因激活腺酰环化酶。RAS激活是通过中介的 在体内通过腺苷酸酶相关蛋白(CAP)。在……里面 此外，CAP似乎通过一种 固有的放线单体结合活性以及通过与 其他细胞骨架蛋白。CAP同源基因也在 哺乳动物。在测试中，所有CAP同源物都含有肌动蛋白 细胞骨架的相互作用。这项提议旨在检验这样一种假设 CaP同系物介导肌动蛋白细胞骨架与细胞外基质之间的相互作用 Ras、Rac、Rho和CDC42等信号蛋白。为了测试这一点 假设我们将(1)确定CAP与 细胞骨架调节酵母中的RAS/cAMP信号，(2)确定 CAP相互作用隔离对CAP细胞骨架功能的影响 酵母中的基因和(3)哺乳动物CAP的纯化和鉴定 细胞。

The goal of this prosal is to understand how signaling pathways invoke changes in the actin cytoskeleton. A number of disease processes are associated with cytoskeletal changes. When cells are ~transformed~ into tumor cells, rearrangements in the actin cytoskeleton increase cell motility and contribute to the changes that allowtumor cells to invade surrounding tissues. Actin also undergoes rapid polymerization when platelets aggregate. Aggregation, which serves to attenuate leakage from bolld vessels, can sometimes restrict blood flow, resulting in strokes and heart attacks. Understanding the regulation of the actin cytoskeleton may provide insighhts into how its reorganization contributes to the progression of a number of important diseases. Many cytoskeletal changes are regulated thorugh the corrdinated actions of several small G proteins including Ras, Rac, Rho and Cdc42. In the budding yeast, Saccharomyces cerevisiae, homologs of the Ras oncogene activate adenylyl cyclase. Ras activation is mediated in vivo through an adenylyl caclase associated protein (CAP). In addition, CAP appears to regulate the actin cytoskeleton through an intrinsic actinmonomer binding activity and through interactions with other cytoskeletal proteins. CAP homologs are also found in mammals. Where tested, all CAP homologs contain the actin cytoskeletal interactions. This proposal aims to test the hypothesis that CAP homologs mediate interactions between the actin cytoskeleton and signaling proteins such as Ras, Rac, Rho and Cdc42. To test this hypothesis we will (1) determine how CAP's interaction with the cytoskeleton regulates Ras/cAMP signaling in yeast, (2) determine the cytoskeletal function of CAP through the isolatioon of CAP-interacting genes in yeast and (3) Purify and characterize CAP from mammalian cells.