Biochemical Regulation of Actin Cytoskeleton Assembly

描述（由申请人提供）：Palladin是一种新的92 kD蛋白， 似乎在肌动蛋白为基础的结构组装中发挥关键作用， 阵我们假设palladin是一种关键的支架蛋白， 多个蛋白质的对接位点，这些蛋白质调节组装和更高阶的 肌动蛋白丝的组织。由于肌动蛋白细胞骨架提供了 许多基本细胞过程的结构框架（包括 扩散、粘附和迁移），重要的是要准确了解如何 palladin起调节细胞骨架组织的作用。为此中央 以下问题将得到解决：（1）什么是结构和 与palladin结合的细胞骨架调节蛋白？为这些 研究中，我们将以序列同源性为指导， palladin和已知的细胞骨架蛋白，以指导我们潜在的结合 伙伴(2)palladin是如何监管的？为了回答这个问题，我们将 当细胞聚集时，palladin被修饰， 进入有丝分裂我们将研究其生化性质 修饰，我们将探讨如何有丝分裂特异性修饰的 palladin影响其与其通常的伙伴结合的能力。(3)什么 palladin的结构域是其结合相互作用所必需的？对接站点 将palladin定位到特定的氨基酸，这样我们就可以设计palladin 缺乏提供某些结合位点的能力的突变体。 然后将这些palladin突变体在活细胞中表达，以探索 对细胞骨架组装的影响。总之，我们认为帕拉丁是一个 独特而强大的工具，用来研究细胞机制， 控制着细胞骨架在生命中的组装、维持和调节 细胞细胞的扩散、粘附和迁移对于这些过程至关重要， 如伤口愈合、炎症反应、神经突生长和癌症 转移;因此，更好地了解肌动蛋白为基础的调节 这些结构在许多不同领域都有潜在的健康益处。

DESCRIPTION (provided by applicant): Palladin is a novel 92 kD protein that appears to play a critical role in the assembly of actin-based structural arrays. We hypothesize that palladin is a key scaffold protein that provides docking sites for multiple proteins that regulate the assembly and higher-order organization of actin filaments. Since the actin cytoskeleton provides the structural framework for many fundamental cellular processes (including spreading, adhesion, and migration), it is important to understand exactly how palladin functions to modulate cytoskeletal organization. To this end, the following questions will be addressed: (1) What are the structural and regulatory proteins of the cytoskeleton that bind to palladin? For these studies, we will be guided by sequence homologies that are shared between palladin and known cytoskeletal proteins, to direct us to potential binding partners. (2) How is palladin regulated? To answer this question, we will take advantage of the observation that palladin becomes modified when cells round up to enter mitosis. We will investigate the biochemical nature of this modification, and we will explore how mitosis-specific modifications of palladin impact upon its ability to bind to its usual partners. (3) What domains of palladin are required for its binding interactions? Docking sites on palladin will be mapped to specific amino acids, so that we can design palladin mutants that are deficient in the ability to provide certain binding sites. These palladin mutants will then be expressed in living cells, to explore the effects on cytoskeletal assembly. In summary, we believe that palladin is a unique and powerful tool with which to study the cellular mechanisms that govern how the cytoskeleton is assembled, maintained and regulated in living cells. Cell spreading, adhesion and migration are critical for processes such as wound healing, inflammation reaction, neurite outgrowth and cancer metastasis; thus, a better understanding of the regulation of actin-based structures could have potential health benefits in many different fields.