CELL BIOLOGY AND BIOCHEMISTRY OF ACTIN SEVERING PROTEINS

肌动蛋白的调节组装对细胞运动至关重要， 保持形状和附着力。多种细胞外刺激 诱导肌动蛋白细胞骨架的重组，但详细的 细胞外刺激导致肌动蛋白重组的机制 仍然不清楚。本提案的长期目标是确定 细胞中调节肌动蛋白组装的分子基础;在这方面， 建议，我们专门解决肌动蛋白丝的作用， 在刺激诱导的形状变化的碎片。肌动蛋白丝切断 加帽蛋白被认为是肌动蛋白的关键调节因子 通过分裂纤维和增加细胞中的 纤维的末端。在体外，调节的高表达的数量增加， 亲和末端增加了单体向长丝的转化，而 增加低亲和力末端的数目增加了 长丝到单体。使用荧光类似物和特异性探针， 将检验肌动蛋白丝断裂是 引起特定类型的形状变化和运动的刺激。

The regulated assembly of actin is critical for cell motility, maintenance of shape and adhesion. A variety of extracellular stimuli induce reorganization of the actin cytoskeleton, but the detailed mechanisms by which extracellular stimuli lead to actin reorganization remain unclear. The long-term objective of this proposal is to define the molecular basis of regulated actin assembly in cells; in this proposal, we specifically address the role of actin filament fragmentation in stimulus induced shape change. Actin filament severing and capping proteins have been postulated to be key regulators of actin dynamics in the cell by fragmenting filaments and increasing the number of filament ends. In vitro, an increase in the number of regulated high affinity ends increases the conversion of monomer to filament, while increasing the number of low affinity ends increases the conversion of filaments to monomer. Using fluorescent analogs and specific probes we will test the hypothesis that actin filament severing is a consequence of stimuli which induce specific types of shape change and motility.