CYTOHESIN-1 PH DOMAIN AND CELLULAR ADHESION

双光子激光扫描显微镜，荧光光谱，分子 生物学和生物化学方法将用于阐明3-OH 磷酸肌醇调节细胞粘连素-1的细胞内行为， 生理作用被认为是调节粘附 通过与整合素受体β 2亚单位的相互作用， 白细胞整合素仲裁细胞与其 外部环境调节许多细胞功能，包括 胚胎发育，肿瘤细胞生长和转移，程序化细胞 死亡和白细胞归巢细胞粘附调节的改变可以 也会导致许多疾病，其中包括类风湿性关节炎， 心血管疾病和癌症。的生理重要性 白细胞整合素是强调的发现，个人缺乏 β 2亚单位患有严重综合征，即白细胞粘附 以不能清除病原体为特征的一种缺乏症，反复发作 感染，并经常在早期死亡。该提案包括 i）为了确定Pleckstrin同源性（PH）是否为 细胞粘连蛋白-1的结构域需要将细胞粘连蛋白-1募集到细胞粘附分子中。 膜表面ii）确定细胞粘连蛋白-IPH结构域的结合是否 与特异性3-OH磷酸肌醇的结合足以募集细胞粘连素-1 到细胞膜上iii）确定细胞粘连蛋白-1的结合是否 足以使其与整合素共定位 β 2和/或ADP核糖基化因子。该项目以 了解DE-磷酸肌醇脂质第二信使如何调节 受体介导细胞粘连素-1时空定位 控制

Two-photon laser scanning microscopy, fluorescence spectroscopy, molecular biology, and biochemical approaches will be used to elucidate how 3-OH phosphoinositide regulate the intracellular behavior of Cytohesin-1, whose physiological role has been suggested to be the regulation of adhesion through its interaction with the beta2 subunit of integrin receptors in leukocytes. Integrins arbitrate communications between the cell and its external environment in regulation of many cellular functions, including embryonic development, tumor cell growth and metastasis, programmed cell death, and leukocyte homing. Altered regulation of cellular adhesion can also contribute to a number of disorders, among them rheumatoid arthritis, cardiovascular disease, and cancer. The physiological importance of leukocyte integrins is underscored by the finding that individuals lacking the beta2 subunit suffer from a severe syndrome, leukocyte adhesion deficiency, characterized by an inability to clear pathogens, recurrent infections, and frequently, death at an early age. The proposal consists of three specific aims: i) To determine if the Pleckstrin Homology (PH) domain of Cytohesin-1 is required to recruit Cytohesin-1 to a cellular membrane surface. ii) To determine if binding of the Cytohesin-I PH domain to a specific 3-OH phosphoinositide is sufficient to recruit Cytohesin-1 to a cellular membrane. iii) To determine whether binding of Cytohesin-1 to the plasma membrane is sufficient for it to co-localize with integrin beta2 and/or with ADP Ribosylation Factor. This project is centered on understanding how DE-phosphoinositide lipid second messengers may regulate the spatial and temporal localization of Cytohesin-1 under receptor control.