Biochemical regulation of the ras-like protein, CDC42

ras 样蛋白 CDC42 的生化调控

• 批准号: 7221221
• 负责人: RICHARD A. CERIONE
• 金额: $ 28.46万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7221221
• 关键词: Actins; Address; Area; B-Cell Lymphomas; Binding; Binding Proteins; Biochemical; Biochemical Genetics; Biological Assay; CDC42 gene; Cell Cycle Progression; Cell Polarity; Cell membrane; Cell physiology; Cells; Cellular biology; Clathrin; Coat Protein Complex I; Coatomer gamma Subunit; Complex; Cytokinesis; Cytoskeleton; Diffuse; Dissociation; Docking; Endoplasmic Reticulum; Epidermal Growth Factor Receptor; Event; Family; Funding; GDP dissociation inhibitor; GTP Binding; GTP-Binding Proteins; Genetic; Glycoproteins; Goals; Golgi Apparatus; Growth Factor Receptors; Guanine Nucleotide Dissociation Inhibitors; Guanine Nucleotide Exchange Factors; Guanosine Diphosphate; Guanosine Triphosphate Phosphohydrolases; Homologous Gene; Human; Laboratories; Lead; Learning; Libraries; Link; Localized; Location; Mammalian Cell; Mediating; Membrane; Methods; Modeling; Molecular; Movement; Mutation; Nude Mice; Numbers; Phosphotransferases; Play; Principal Investigator; Process; Protein Family; Proteins; Range; Receptor Down-Regulation; Recycling; Regulation; Resolution; Roentgen Rays; Role; Running; Saccharomyces cerevisiae; Series; Signal Pathway; Signal Transduction; Signaling Protein; Site; Small Interfering RNA; Sorting - Cell Movement; Stomatitis; Testing; Vesicle; Viral; Work; Yeasts; base; cdc42 GTP-Binding Protein; cell growth; cell growth regulation; cell motility; cellular targeting; design; genetic regulatory protein; inhibitor/antagonist; insight; interest; intersectin 1; member; metaplastic cell transformation; mouse Gdi2 protein; mutant; nexin; programs; ras-Related G-Proteins; response; rho; structural biology; three dimensional structure; trafficking; tumor

DESCRIPTION (provided by applicant): The Ras-related GTP-binding protein Cdc42 has been implicated in a number of fundamentally important cellular processes including the establishment of cell polarity and motility through influences on the actin cytoskeleton, and the regulation of cell-cycle progression. The tight regulation of the GTP-binding/GTPase cycle of Cdc42 is essential to its cellular functions. Mutations that trap Cdc42 in either the GDP-bound or GTP-bound state inhibit cell growth, whereas those that give rise to an accelerated cycling of Cdc42 between these states lead to cellular transformation and tumor formation in nude mice. During the past funding period, we have combined biochemical, genetic, and structural biology-based approaches to study the regulation of Cdc42 by guanine nucleotide exchange factors and the Rho-GDP-dissociation inhibitor (RhoGDI), as well as examined the interactions of activated Cdc42 with various downstream signaling targets, including ACK (Activated Cdc42- associated kinase) and IQGAP. In addition, we have identified two new targets for Cdc42, the gamma-coatomer subunit (gammaCOP) of the COPI complex and the p85Cool-1 (for Cloned-out of library)/beta-Pix (PAK-interactive exchange factor) protein. These studies have provided us with new information regarding the molecular mechanisms underlying the cellular regulation and function of Cdc42. However, perhaps most important, work during the past funding period has raised an interesting and somewhat unanticipated role for Cdc42, namely linking intracellular trafficking activities to cell signaling and cell growth regulation. In this renewal application, we plan to examine this interesting new role for Cdc42 by focusing on those upstream regulators and downstream target/effectors that appear to implicate most strongly Cdc42 in cellular trafficking functions. This will constitute 4 lines of study. Aim la.) Identify and characterize the protein complexes that couple the activation of Cdc42 to the sorting and trafficking of EGF receptors. Aim lb.) Determine why Cdc42-gammaCOP interactions are essential for Cdc42-mediated cellular transformation. Aim 2a.) Determine whether IQGAP serves as a docking site for Cdc42 and other proteins involved in intracellular trafficking functions. Aim 2b.) Determine whether RhoGDI plays a fundamental role in Cdc42-mediated intracellular trafficking activities. These studies are expected to yield important new insights into a critical cellular function for Cdc42 that may form the basis for a diversity of Cdc42-mediated cellular responses ranging from cell cycle progression and cellular transformation to morphological and actin cytoskeletal changes.

描述（由申请人提供）：Ras 相关 GTP 结合蛋白 Cdc42 涉及许多基本重要的细胞过程，包括通过影响肌动蛋白细胞骨架来建立细胞极性和运动性，以及细胞周期进程的调节。 Cdc42 的 GTP 结合/GTP 酶循环的严格调节对其细胞功能至关重要。将 Cdc42 捕获在 GDP 结合或 GTP 结合状态的突变会抑制细胞生长，而导致 Cdc42 在这些状态之间加速循环的突变会导致裸鼠中的细胞转化和肿瘤形成。在过去的资助期间，我们结合了基于生化、遗传和结构生物学的方法来研究鸟嘌呤核苷酸交换因子和 Rho-GDP 解离抑制剂 (RhoGDI) 对 Cdc42 的调节，并检查了激活的相互作用Cdc42 具有各种下游信号传导靶标，包括 ACK（激活的 Cdc42 相关激酶）和 IQGAP。此外，我们还确定了 Cdc42 的两个新靶标，即 COPI 复合物的 γ 涂层异构体亚基 (gammaCOP) 和 p85Cool-1（用于从文库克隆）/beta-Pix（PAK 相互作用交换因子）蛋白。这些研究为我们提供了有关 Cdc42 细胞调节和功能的分子机制的新信息。然而，也许最重要的是，过去资助期间的工作为 Cdc42 带来了一个有趣且有些出乎意料的作用，即将细胞内贩运活动与细胞信号传导和细胞生长调节联系起来。在此更新应用中，我们计划通过关注那些似乎与细胞运输功能中 Cdc42 最密切相关的上游调节因子和下游靶标/效应因子来研究 Cdc42 的这一有趣的新作用。这将构成 4 个研究方向。目标la.)鉴定并表征将Cdc42的激活与EGF受体的分选和运输耦合的蛋白质复合物。目标 lb.) 确定为什么 Cdc42-gammaCOP 相互作用对于 Cdc42 介导的细胞转化至关重要。目标 2a.) 确定 IQGAP 是否充当 Cdc42 和参与细胞内运输功能的其他蛋白质的对接位点。目标 2b.) 确定 RhoGDI 是否在 Cdc42 介导的细胞内贩运活动中发挥基本作用。这些研究有望对 Cdc42 的关键细胞功能产生重要的新见解，这可能构成 Cdc42 介导的多种细胞反应的基础，范围从细胞周期进展和细胞转化到形态和肌动蛋白细胞骨架变化。