A MODEL SYSTEM FOR STUDY OF CELL-MATRIX INTERACTION

该补助金的目的是开发一种具有广泛应用的模型， 细胞与细胞外基质相互作用的研究。 一个新兴 在基质受体领域的一个概念是， 在整联蛋白-配体系统中，这种受体-配体多样性可以 提供了一种机制，通过这种机制，细胞特异性地响应于 细胞外基质 拟议的研究将侧重于确定 这种受体-配体复制的潜在机制，并提供 关于整合素调节细胞行为的重要信息- 矩阵相互作用 我们将开发整合素α 3 β 1与 层粘连蛋白和纤连蛋白。 α 3 β 1代表了 与许多已知的整合素相关。 具体来说，我们将 定位和描绘层粘连蛋白和纤连蛋白内的结合位点 对于alpha 3 beta1。 此外，我们还将描述 层粘连蛋白和纤连蛋白的α 3 β 1。 这项工作将使用 蛋白水解和化学衍生片段、重组多肽和 从层粘连蛋白、纤连蛋白和α 3 β 1衍生的合成肽， 固相结合分析，亲和层析，交联表位 作图实验和单克隆抗体生产。 采取 总之，这些研究将建立潜在的分子机制 α 3 β 1与层粘连蛋白和纤连蛋白的相互作用。 我们最近已经证明了一种细胞类型特异性的调节， α 3 β 1配体选择性。 这部分拟议的研究将 扩展我们的初步发现，并确定可能的机制， 这种细胞类型特异性调节受体结合。 这些 将使用cDNA分析和免疫学方法进行研究。 接近。 最后，拟议的研究将确定和表征 α 3 β 1的其它配体。 使用α 3 β 1作为亲和矩阵， 已经分离出一种新的潜在分子，可能与细胞-细胞 通过α 3 β 1结合。 拟议的工作将进一步体现 这种新的糖蛋白，并探索可能性，但额外的 α 3 β 1相互作用的配体。 我们期望这些研究将有助于我们了解 细胞选择性与基质蛋白相互作用的机制; 从而提供了对细胞行为的调节的洞察， 细胞外基质 此外，对重要性的理解 对于这种受体-配体冗余将从拟议的研究中发展出来。

The purpose of this grant is to develop a model with broad applications for the study of cell interaction with extracellular matrix. An emerging concept in the matrix-receptor field is that there is redundancy inherent in the integrin-ligand system and this receptor-ligand multiplicity may provide a mechanism by which cells specifically respond to the extracellular matrix. The proposed research will focus on identifying the underlying mechanisms for this receptor-ligand duplication and provide important information on the regulation of cellular behavior by integrin- matrix interactions. We will develop as our model, the binding of the integrin alpha3beta1 to laminin and fibronectin. Alpha3beta1 is representative of the multiplicity associated with many of the known integrins. Specifically, we will localized and delineate the binding sites within laminin and fibronectin for alpha3beta1. In addition, we will characterize the binding sites in alpha3beta1 for both laminin and fibronectin. This work will be done using proteolytic and chemically derived fragments, recombinant polypeptides and synthetic peptides, derived from laminin, fibronectin and alpha3beta1 in solid phase binding assays, affinity chromatography, crosslinking epitope mapping experiments and for monoclonal antibody production. Taken together, these studies will establish the molecular mechanisms underlying alpha3beta1 interaction with laminin and fibronectin. We have recently demonstrated a cell type specific modulation of alpha3beta1 ligand selectivity. This portion of the proposed research will expand on our preliminary findings and identify possible mechanisms for this cell type specific modulation of receptor binding. These investigations will be done using cDNA analysis and immunological approaches. Finally, the proposed studies will identify and characterize other ligands for alpha3beta1. Using alpha3beta1 as an affinity matrix we have isolated a new potential molecule that may be involved in cell-cell binding through alpha3beta1. The proposed work will further characterize this new glycoprotein and explore the possibilities of yet additional ligands for alpha3beta1 interaction. We anticipate that these studies will contribute to our understanding of the mechanisms by which cell selectivity interact with matrix proteins; thus providing insight into the regulation of cellular behavior by the extracellular matrix. Furthermore, an understanding of the significance for such receptor-ligand redundancy will evolve from the proposed research.