CYTOSKELETON/MEMBRANE INTERACTIONS

细胞骨架/膜相互作用

• 批准号: 2603459
• 负责人: ELIZABETH J. LUNA
• 金额: $ 27.17万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2603459
• 关键词: Dictyostelium; actin binding protein; animal tissue; biological signal transduction; cell adhesion; cell cell interaction; cell motility; clone cells; cytoskeleton; diacylglycerols; enzyme linked immunosorbent assay; high performance liquid chromatography; immunoprecipitation; laboratory mouse; laboratory rabbit; membrane activity; membrane potentials; membrane proteins; molecular cloning; phosphorylation; polymerase chain reaction; protein structure function; protoplasm motility; western blottings

Dynamic changes in cell motility and in the actin-based membrane skeleton occur during immune cell functioning, neuronal outgrowth, wound healing, and the transformation of cells into invasive cancers. Although these changes are thought to involve rearrangements of the proteins at the actin-membrane interface, the relevant interacting proteins are largely unknown. The proposed research will continue the characterization of membrane skeletons in amoeboid cells, e.g., cells such as unactivated neutrophils and Dictyostelium amoebae. Although these cells lack stable attachments to other cells or to extracellular matrices, their membranes contain cytoskeletal linkages responsible for the spatial and temporal control of cell shape and/or the regulation of intracellular responses to extracellular signals. These 'amoeboid' membrane skeletons appear to be structurally distinct from the membrane skeletons that characterize sites of cell anchorage. Two types of membrane-associated actin-binding proteins will be investigated: (a) transmembrane proteins that provide direct connections between the cell surface and the actin cytoskeleton, and (b) peripheral membrane proteins that can be recruited from the cytoplasm to the membrane skeleton where they may regulate the assembly or stability of membrane-associated actin filaments. The specific aims of the proposed research are: (1) to generate mutant cell lines for ongoing functional analyses of Dictyostelium ponticulin, the first integral membrane protein shown to bind directly to actin and the only integral membrane protein with demonstrated actin nucleation activity; (2) to determine the molecular mechanism by which diacylglycerols mediate increases in the actin nucleation activity of purified Dictyostelium plasma membranes; and (3) to ascertain whether membrane-associated actin- binding proteins identified in neutrophils and cervical carcinoma cells are structurally or functionally similar to ponticulin. This research will lead to a better understanding of the molecular mechanisms involved in pseudopod formation and stabilization, in the regionalization of the plasma membrane, and in cell detachment from surfaces or other cells. This research thus will both increase our knowledge of normal motile processes and shed light on defects underlying pathological conditions, including birth defects, cancer cell metastasis, and dementia caused by transit of HIV-laden macrophages across the blood-brain barrier.

细胞运动和基于肌动蛋白的膜骨骼的动态变化 发生在免疫细胞功能，神经元出现，伤口愈合， 以及细胞转化为侵入性癌症。 虽然这些 人们认为变化涉及蛋白质的重排 肌动蛋白 - 膜界面，相关的相互作用蛋白在很大程度上是 未知。 拟议的研究将继续表征 变形虫细胞中的膜骨架，例如，诸如未激活之类的细胞 嗜中性粒细胞和柱状变形虫。尽管这些细胞缺乏稳定 附着在其他单元格或细胞外矩阵，其膜 包含负责空间和时间的细胞骨架链接 控制细胞形状和/或细胞内反应的调节 到细胞外信号。这些“变形虫”膜骨骼似乎 在结构上与表征的膜骨架不同 细胞锚定部位。两种类型的膜相关肌动蛋白结合 将研究蛋白质：（a）提供的跨膜蛋白 细胞表面与肌动蛋白细胞骨架之间的直接连接， （b）可以从 细胞质到膜骨架可以调节组件 或膜相关肌动蛋白丝的稳定性。具体目标 拟议的研究中是：（1）生成突变细胞系 dictyostelium Ponticulin的持续功能分析，第一个 表现为直接与肌动蛋白结合的整体膜蛋白，唯一 具有肌动蛋白成核活性的整体膜蛋白； （2）确定二酰基甘油介导的分子机制 纯化的dictyostelium的肌动蛋白成核活性增加 质膜； （3）确定是否与膜相关肌动蛋白 - 在中性粒细胞和宫颈癌细胞中鉴定的结合蛋白 在结构或功能上与ponticulin相似。这项研究 将导致更好地理解所涉及的分子机制 在伪足形成和稳定中， 质膜，以及从表面或其他细胞的细胞脱离中。 因此，这项研究都将增加我们对正常运动的了解 过程并阐明了病理性条件的缺陷， 包括先天缺陷，癌细胞转移和由 在血脑屏障中载有HIV的巨噬细胞的过渡。