ANNEXIN PHOSPHORYLATION--CAUSES AND CONSEQUENCES

膜联蛋白是一组同源的、钙依赖的、膜- 结合蛋白可能是一系列不同过程的基础， 在膜表面。 这个蛋白质家族的三个成员，膜联蛋白I 膜联蛋白II（calpactin）和膜联蛋白VI（p68），已经被 当细胞被刺激分裂时， 癌基因或有丝分裂原，这表明这些蛋白质可能在 与恶性肿瘤相关的细胞质和细胞膜变化 转型 此外，已经证明膜联蛋白I和II是 当嗜铬细胞受到刺激， 胞吐，表明膜联蛋白也可能控制膜融合， 分化的分泌细胞 该项目的目标是 了解膜联蛋白磷酸化在控制细胞凋亡中的作用， 功能协调发展的 将绘制膜联蛋白上磷酸化的位点。 磷酸化对膜联蛋白I结构的影响将是 通过X射线衍射分析测定。 磷酸化的影响 对膜结合、膜聚集和相关的体外 将测定膜联蛋白的活性。 磷酸化位点 将通过定点诱变进行修饰以产生重组 磷酸化膜联蛋白的蛋白质模型。 原住民的能力 或修饰的膜联蛋白影响哺乳动物细胞将通过 将这些蛋白质导入完整的或透化的分泌细胞中 和成纤维细胞。 这些研究将为我们了解细胞 膜联蛋白控制的功能和癌基因的作用， 有丝分裂原调节这些功能。 这些知识可能会导致新的 控制恶性肿瘤相关细胞变化的方法 转型

The annexins are a group of homologous, calcium-dependent, membrane- binding proteins that may underlie a diverse array of processes occurring at membrane surfaces. Three members of this protein family, annexin I (lipocortin), annexin II (calpactin), and annexin VI (p68), have been shown to undergo phosphorylation when cells are stimulated to divide by oncogenes or mitogens, suggesting these proteins may play roles in cytoplasmic and membrane changes associated with malignant transformation. In addition, annexins I and II have been shown to be phosphorylated in the chromaffin cell when it is stimulated to carry out exocytosis, suggesting the annexins may also control membrane fusion in differentiated secretory cells. The goal of this project is to understand the role of annexin phosphorylation in control of cellular functions. The sites of phosphorylation on the annexins will be mapped. The effect of phosphorylation on the structure of annexin I will be determined by X-ray diffraction analysis. The effects of phosphorylation on the membrane-binding, membrane-aggregating, and related in vitro activities of the annexins will be determined. The phosphorylation sites will be modified by site-directed mutagenesis to generate recombinant protein models of the phosphorylated annexins. The ability of the native or modified annexins to influence mammalian cells will be examined by introducing these proteins into intact or permeabilized secretory cells and fibroblasts. These studies will provide insights into the cellular functions controlled by the annexins and the role of oncogenes and mitogens in regulating these functions. This knowledge may lead to novel methods of controlling cellular changes associated with malignant transformation.