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

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)蛋白信号与肿瘤发生和2)细胞个体和协调作用的研究 黏附蛋白在调节细胞形态、力传递和细胞运动中起重要作用。我们在G蛋白方面的工作是 以RAS和异三聚体G-蛋白为中心。我们实验室的最新发现挑战了一个长期存在的教条 在这一领域，G蛋白的致癌激活主要是由核苷酸循环中的缺陷驱动的。然而， 越来越清楚的是，G蛋白中的密码子和残基特异的激活突变可以推动 肿瘤的发生有不同的机制。换句话说，并不是所有激活的突变都是平等的。我们 提出旨在了解残基特异性激活突变如何独特地改变G蛋白的研究 结构、核苷酸循环、蛋白质识别和信号传递，这些可能是提高精确度的关键 对抗G蛋白介导的肿瘤发生的药物途径。我们的实验室还发现了一种 翻译后修饰和pH调节激活G蛋白的机制。我们强烈建议 综合多学科的结构、生物化学和细胞生物学方法来研究这些 信号转导和肿瘤发生中的新的翻译后修饰。我们的第二个主题是细胞 黏附蛋白、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收缩 心脏疾病中的暴力。我们还将研究纽蛋白和Metavinculin如何在 以力依赖的方式调节定向细胞的运动。

Abstract 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 G-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.