PILOT STUDY--TRANSMEMBRANE GLYCOPROTEIN INTERACTIONS

细胞膜-跨膜糖蛋白相互作用具有 在包括细胞在内各种细胞功能中的重要作用 生长、细胞粘附和信号转导。 几种蛋白质 介导细胞骨架与蛋白质的相互作用， 细胞膜上的结构。 ERM蛋白（埃兹蛋白、膜突蛋白和 radixin）是一个新发现的家族，推测是膜- 细胞骨架接头。 突变和扰动， 细胞膜连接蛋白，包括ERM蛋白，可以 干扰正常细胞粘附。 通过这种方式，细胞可以获得 致瘤特性。 我们建议研究跨膜糖蛋白，如 细胞粘附分子C-CAM 105、硫酸肝素 蛋白聚糖多配体蛋白聚糖-1和上皮粘蛋白MUC 1是 与细胞骨架锚定蛋白或其他ERM相关 proteins. 跨膜糖蛋白的胞质尾区 将用于亲和色谱研究，以检测 代谢标记的细胞裂解物中的相互作用蛋白。的 将用纯化的蛋白质研究鉴定的相互作用， 将表征这些蛋白质上的结合位点。 的 埃兹蛋白与跨膜糖蛋白的结合也将被 通过将ezrin cDNA转染到培养细胞中进行研究， 确定埃兹蛋白是否重新分布跨膜 糖蛋白和分子决定簇的测定 蛋白质相互作用的研究将阐明埃兹蛋白或其他 细胞骨架分子在C-CAM 105、MUC 1和 多配体蛋白聚糖-1。

Cytoskeletal-transmembrane glycoprotein interactions have an important role in various cellular functions, including cell growth, cell adhesion, and signal transduction. Several proteins mediate the interactions of the cytoskeleton with proteins and structures on the cell membrane. ERM proteins (ezrin, moesin and radixin) are a newly found family postulated to be membrane- cytoskeleton linkers. The mutation and perturbations in the cytoskeletal-membrane linker proteins, including ERM proteins, may disturb normal cell adhesion. In this way the cells could obtain tumorigenic properties. We propose to study whether transmembrane glycoproteins such as the cell adhesion molecule C-CAM 105, the heparin sulfate proteoglycan syndecan-1, and the epithelial mucin MUC1 are associated with cytoskeletal anchorage proteins or other ERM proteins. The cytoplasmic tails of transmembrane glycoproteins will be used in affinity chromatography studies to detect interacting protein in metabolically labeled cell lysates. The identified interactions will be studied with purified proteins and the binding sites on these proteins will be characterized. The association of ezrin with transmembrane glycoproteins will also be studied by transfection of ezrin cDNA into cultured cells to determine whether ezrin redistributes the transmembrane glycoproteins and the determination of the molecular determinants of protein interactions will clarify the role of ezrin or other cytoskeletal molecules in the function of C-CAM 105, MUC1, and syndecan-1.