Functions and mode of action of novel regulatory systems for cell adhesion and motility

我们发现了一种新的细胞粘附调控系统。该系统由连接素和脱落素组成。连接蛋白是一种类似免疫球蛋白的细胞粘附分子，而afadin是一种连接连接蛋白和肌动蛋白细胞骨架的f -aotin结合蛋白。连接素-黄素系统在上皮细胞中组织粘附物和紧密连接。我们还发现了一种新的细胞运动调节系统。该系统由frabin和Cdc42小G蛋白组成。Frabin是一种激活Cdc42的f -actin混合蛋白。在2000- 2001年的支持下，我们研究了这些连接素-afadin和frabin-Cdc42系统的功能和作用方式。结果表明：(1)在上皮细胞中，连接素-afadin系统将cadherin-catenin和jam - zo - 1系统招募到连接素为基础的细胞-细胞粘附位点。在神经元中，连接素-腺嘌呤系统定位于突触，参与突触的信息传递。在睾丸中，连接素-卵黄素系统参与支持细胞-精子细胞连接的形成，对精子细胞的形态发生至关重要。(2) Frabin与特定的肌动蛋白和膜结构结合，激活这些结构附近的Cdc42和Rac小G蛋白，最终导致细胞运动。frabin的f -actin结合活性与cdc42激活活性协同作用于细胞运动。

We have found a novel regulatory system for cell adhesion. This system consists of nectin and afadin. Nectin is an immunoglobulin-like cell adhesion molecule, and afadin is an F-aotin-binding protein that connects nectin to the actin cytoskeleton.The nectin-afadin system organizes adherens and tight jjunctions in epithelial cells.We have also found a novel regulatory system for cell motility. This system consists of frabin and Cdc42 small G protein. Frabin is an F-actin-blnding protein that activates Cdc42. During this support from2000-to 2001, we have studied the functions and mode of action of these nectin-afadin and frabin-Cdc42 systems. The results obtained are as follows :(1) In epithelial cells, the nectin-afadin system recruits the cadherin-catenin and JAM-ZO-lsystems to nectin-based cell-cell adhesion sites. In neurons, the nectin-afadinsystemis localized at synapses and involved information of synapses. In testis, the nectin-afadin system is involved in formation of Sertoli-spermatid junctions and essential for spermatid morphogenesis.(2) Frabin associates with specific actin and membrane structures and activates not only Cdc42 and but also Rac small G protein in the vicinity of these structures, eventually to leading to cell motility. The F-actin-binding activity of frabin cooperatively functions with the Cdc42-activating activity in cell motility.