Structure and Mechanism of G-proteins and cell adhesion proteins in regulation of cell growth and motility

家长奖摘要 本项目主要研究两个主题：1）阐明鸟嘌呤核苷酸的新的驱动机制 结合（G）蛋白信号传导和肿瘤发生和2）调查的个人和协调的作用， 细胞粘附蛋白在调节细胞形态、力传递和细胞运动中的作用。我们在G- 蛋白质集中在RAS和异源三聚体Gα蛋白。我们实验室挑战A的最新发现 该领域长期以来的教条是，G蛋白的致癌激活主要是由以下缺陷驱动的： 核苷酸循环然而，越来越清楚的是，密码子和残基特异性激活 G蛋白的突变可以通过不同的机制驱动肿瘤发生。换句话说，并不是所有的激活 突变是平等的。我们提出的研究旨在了解如何残基特异性激活 突变独特地改变了G蛋白结构、核苷酸循环、蛋白质识别和信号传导， 可能是开发精确医学方法以拮抗G蛋白介导的 肿瘤发生我们的实验室还发现了G蛋白激活的新机制， 翻译修饰和pH调节。我们建议高度集成的多学科结构， 生物化学和细胞生物学方法来询问这些新的翻译后 信号传导和肿瘤发生的改变。我们的第二个主题是关注细胞粘附 蛋白质，粘着斑蛋白和后粘着斑蛋白。这些细胞粘附蛋白是同种型，在细胞粘附中起关键作用。 调节细胞形态、分化、力传递和定向细胞迁移。我们提出 实验性检查黏着斑蛋白和metavinculin介导的丝状肌动蛋白的新模型的研究 组装和膜插入，进行细胞研究，以阐明metavinculin如何协调 调节黏着斑蛋白功能，并阐明metavinculin心肌病突变如何失调 心脏病中的收缩力我们还将研究黏着斑蛋白和后黏着斑蛋白如何参与 丝状肌动蛋白以力依赖的方式调节定向细胞运动。

Abstract of Parent Award This project focuses on two themes: 1) elucidation of novel mechanisms that drive guanine nucleotide binding (G)-protein signaling and tumorigenesis and 2) investigation of individual and coordinated roles of cell adhesion proteins in regulating cell morphology, force transmission and cell motility. Our work on G- proteins is centered on RAS and heterotrimeric Gα-proteins. Recent findings from our lab challenge a long-held dogma in the field that oncogenic activation of G-proteins is primarily driven by defects in nucleotide cycling. However, it is becoming increasingly clear that codon and residue specific activating mutations in G-proteins can drive tumorigenesis by distinct mechanisms. In other words, not all activating mutations are created equal. We propose studies aimed at understanding how residue specific activating mutations uniquely alter G-protein structure, nucleotide cycling, protein recognition and signaling, that may be key to developing precision medicine approaches to antagonize G-protein mediated tumorigenesis. Our lab has also uncovered novel mechanisms of G-protein activation by post- translational modification and pH regulation. We propose highly integrated multidisciplinary structural, biochemical and cell biology approaches to interrogate the role of these novel posttranslational modifications in signaling and tumorigenesis. Our second theme is focused on the cell adhesion proteins, vinculin and metavinculin. These cell adhesion proteins are isoforms that play a key role in regulation of cell morphology, differentiation, force transmission and directed cell migration. We propose studies to experimentally examine new models for vinculin and metavinculin-mediated filamentous actin assembly and membrane insertion, conduct cellular studies to elucidate how metavinculin coordinately regulates vinculin function, and elucidate how metavinculin cardiomyopathy mutations dysregulate contractile force in heart disease. We will also investigate how vinculin and metavinculin engage filamentous actin in a force dependent manner to regulate directed cell motility.