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

家长奖摘要 该项目的重点是两个主题：1)阐明驱动鸟嘌呤核苷酸的新机制 结合(G)-蛋白信号转导与肿瘤发生和2)个体和协调作用的研究 细胞黏附蛋白调节细胞形态、力传递和细胞运动。我们在G-上的工作- 蛋白质以RAS和异三聚体Gα-蛋白为中心。我们实验室的最新发现挑战了 该领域长期以来的一种教条，认为G蛋白的致癌激活主要是由 核苷酸循环。然而，越来越清楚的是，密码子和残基的特异性激活 G蛋白的突变可以通过不同的机制推动肿瘤的发生。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残基特异性激活是如何 突变独特地改变了G蛋白的结构、核苷酸循环、蛋白质识别和信号传递， 可能是发展对抗G蛋白介导的精确医学方法的关键 肿瘤发生学。我们的实验室还发现了G蛋白通过后激活的新机制 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基因的作用 信号转导和肿瘤发生中的修饰。我们的第二个主题是细胞黏附 蛋白质、纽蛋白和偏维A蛋白。这些细胞黏附蛋白是起关键作用的异构体 调节细胞形态、分化、力传递和定向细胞迁移。我们建议 实验检测纽球蛋白和豆球蛋白介导的丝状肌动蛋白新模型的研究 组装和膜插入，进行细胞研究以阐明Metavinculin如何协调 调节纽蛋白功能，并阐明Metavinculin心肌病突变如何失调 心脏疾病中的收缩力量。我们还将研究纽蛋白和偏钙蛋白是如何相互作用的 丝状肌动蛋白以一种力依赖的方式调节定向细胞的运动。

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.