ACTIN/MYOSIN INTERACTIONS IN CELL MOTILITY

细胞运动中肌动蛋白/肌球蛋白的相互作用

• 批准号: 6018498
• 负责人: THOMAS D. POLLARD
• 金额: $ 43.52万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-07-01 至 2002-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6018498
• 关键词: Acanthamoeba; Schizosaccharomyces pombe; X ray crystallography; actins; affinity chromatography; analytical ultracentrifugation; cell motility; electron microscopy; fluorescence microscopy; image processing; light microscopy; membrane activity; microtubules; myosins; nuclear magnetic resonance spectroscopy; phagocytosis; phosphorylation; polymerase chain reaction; protein isoforms; protein structure function; tissue /cell culture

Our goals are to understand the mechanisms of (1) assembly of myosin-II into bipolar filaments, (2) cytokinesis and (3) organelle movements by myosin-I. To reach these goals, we propose the following studies: 1. Assembly and function of myosin-II. We will determine the atomic structure of the C-terminal part of the tail of Acanthamoeba myosin-II that is required for the formation of minifilaments. We will compare the assembly kinetics of C-terminal fragments with intact myosin tails to test our hypothesis that assembly is favored by intramolecular diffusion. 2. Regulation of cytokinesis. We will use biochemistry, genetics and molecular genetics to study cytokinesis in Schizosaccharomyces pombe. We will determine genetic interactions between the two isoforms of myosin-II and gene products known to participate in cytokinesis. After identifying and characterizing the light chains associated with the two isoforms of myosin-II, we will use genetic screens to identify new components that regulate the time and position of furrow formation. 3. Interaction of myosin-I with membranes. We will characterize lipid binding properties of Acanthamoeba myosin-I isozymes, analyze the assembly of myosin-I tails into higher order structures in solution and on lipid surfaces and determine which parts of the myosin-I molecule are required to target the three isoforms to specific membranes in vivo. To aid in this analysis, we will attempt to crystallize the tail myosin- I for high resolution structure determination. This work will contribute to our understanding of basic cellular process such as cell division (as important feature of cancer), cellular motility (important for tumor metastasis), phagocytosis (important in defense against microbial pathogens) and muscle contraction.

我们的目标是了解（1）肌球蛋白-II组装的机制 进入双极丝，（2）细胞因子和（3）细胞器运动 肌球蛋白-i。 为了实现这些目标，我们提出以下研究： 1。肌球蛋白-II的组装和功能。 我们将确定原子 Acanthamoeba肌球蛋白-II的C末端部分的结构 这是形成微型段所必需的。 我们将比较 具有完整肌球蛋白尾巴的C末端片段的组装动力学 为了测试我们的假设，即组件有利于分子内组件 扩散。 2。细胞因子的调节。 我们将使用生物化学，遗传学和 分子遗传学研究细胞因子pombe中的细胞因子。 我们将确定两种同工型之间的遗传相互作用 已知参与细胞因子的肌球蛋白-II和基因产品。 后 识别和表征与两者相关的光链 肌球蛋白-II的同工型，我们将使用遗传筛选来识别新的 调节犁沟形成时间和位置的组件。 3。肌球蛋白I与膜的相互作用。 我们将表征脂质 acanthamoeba肌球蛋白-I同工酶的结合特性，分析 肌球蛋白I尾巴组装成溶液中的高阶结构 在脂质表面上，确定肌球蛋白I分子的哪些部分是 需要将三种同工型靶向体内特定膜。 为了帮助进行此分析，我们将尝试使尾肌球蛋白结晶 我进行高分辨率结构的确定。 这项工作将有助于我们对基本蜂窝过程的理解 例如细胞分裂（作为癌症的重要特征），细胞 运动性（对肿瘤转移很重要），吞噬作用（重要 防御微生物病原体）和肌肉收缩。