EXTRACELLULAR MATRIX MODULATION OF CELL PHENOTYPE

产品说明：细胞外基质（ECM）为细胞提供线索，因此充当细胞增殖、迁移、粘附和分化的框架。细胞对基质组成和结构变化的反应通过与整合素和基质蛋白的其他受体的相互作用来解释。细胞骨架重组、细胞形态变化、信号转导级联激活、基因表达模式调节和细胞周期进展代表了对基质信号的一些细胞反应。这项新提议的总体目标是通过ECM与整合素受体的相互作用来提供对细胞表型控制的见解。纤连蛋白（FN）是一种重要的ECM成分，与三维纤维基质内的细胞相互作用。FN基质原纤维的结构可以通过不同重组天然和突变FN的细胞组装而变化。主要研究者发现，结构不同的FN基质对细胞生长速率和黏着斑激酶的活化具有不同的影响。这些差异效应通过抑制FN原纤维形成而消除。基质FN调节细胞功能的机制将使用细胞培养系统结合显微镜，生物化学和分子方法进行研究。目的1是分析粘着斑成分、细胞形状和其他细胞表面受体在FN基质结构生长反应中的作用。目的2是研究下游信号通路包括MAP激酶和PI 3-激酶对细胞生长和FN组装的调节的贡献。整合素胞质结构域对于将信号从基质通过整合素传递到细胞内区室是必不可少的。为了剖析胞质结构域功能，PI开发了一种体内秀丽隐杆线虫模型系统。在表达含有整联蛋白B尾的嵌合蛋白的转基因线虫中产生显性阴性表型。目的3是表征在这些转基因线虫中由完整和突变的B尾引起的表型。目的4筛选转基因线虫突变株，鉴定整合素功能相关基因。

DESCRIPTION: (adapted from applicant's abstract) The extracellular matrix (ECM) provides cues to cells and thus serves as a framework for cell proliferation, migration, adhesion, and differentiation. Cell responses to changes in matrix composition and structure are interpreted through interactions with integrins and other receptors for matrix proteins. Cytoskeletal reorganization, changes in cell morphology, activation of signal transduction cascades, modulation of gene expression patterns, and progression through the cell cycle represent some of the cellular responses to matrix signals. The overall goal of this new proposal is to provide insights into the control of cell phenotype by ECM interactions with integrin receptors. Fibronectin (FN), an essential ECM component, interacts with cells from within a 3-dimensional fibrillar matrix. The structure of FN matrix fibrils can be varied by cell assembly of different recombinant native and mutant FNs. The principal investigator has found that structurally distinct FN matrices have different effects on cell growth rates and activation of focal adhesion kinase. These differential effects are ablated by inhibition of FN fibril formation. The mechanisms by which matrix FN modulates cell function will be investigated using cell culture systems combined with microscopic, biochemical, and molecular approaches. Aim 1 is to analyze the role of focal adhesion components, cell shape, and other cell surface receptors in the growth response to FN matrix structure. Aim 2 is to examine the contributions of downstream signaling pathways involving MAP kinase and PI3-kinase to cell growth and regulation of FN assembly. Integrin cytoplasmic domains are essential for the transmission of signals from the matrix through integrins to intracellular compartments. To dissect cytoplasmic domain function, the PI has developed an in vivo, Caenorhabditis elegans model system. Dominant negative phenotypes are generated in transgenic nematodes expressing chimeric proteins containing integrin b tails. Aim 3 is to characterize the phenotypes caused by intact and mutant b tails in such transgenic nematodes. Aim 4 is to to screen mutant transgenic nematode lines and thus identify genes that particpate in integrin function.