ACTIN ASSEMBLY DURING YEAST POLARIZED CELL GROWTH

超出提供的空间。细胞极化在胚胎发育、细胞运动和细胞分化等许多生理过程中起着至关重要的作用。阐明细胞极性形成的机制对于理解发育异常和疾病，如侵袭性肿瘤和动脉硬化具有重要意义。识别专门产生细胞极性的分子可能会揭示这些疾病的新治疗靶点。此外，细胞如何打破对称性并建立极性是细胞生物学中的一个深刻问题。了解细胞固有的极化能力可能有助于深入了解支配细胞组织和形态发生的物理原理在许多真核细胞类型中，细胞极性的关键调节因子是Rho家族GTP酶CDc42。在细胞极化过程中，CDC42以一种局部的方式被激活，并诱导下游事件，最重要的是，局部肌动蛋白细胞骨架元件的产生。这项提议的目的是要了解CdC42如何诱导肌动蛋白细丝的极化聚合。我们将继续我们正在进行的工作，研究肌动蛋白细丝是如何在细胞皮质成核的，以及CDC42如何在细胞极化过程中定义肌动蛋白成核的位置。我们还将研究CDC42的激活形式驱动细胞对称性最初破坏的机制。表演网站========================================Section End===========================================

EXCEED THE SPACE PROVIDED. Cell polarization is fundamentally important for many physiological processes such as embryonic development, cell motility and cell differentiation. Elucidation of the mechanism underlying cell polarity establishment is important for understanding developmental abnormalities and diseases such as invasive tumor and arteriosclerosis. Identification of the molecules that are specialized in cell polarity generation may reveal novo therapeutic targets for these diseases. In addition, how cells break symmetry and establish a polarity is a profound problem in cell biology. Understanding cell's intrinsic ability to polarize may lead to fundamental insights into the physical principles that govern cellular organization and morphogenesis A key regulator of cell polarity in many eukaryotic cell types is the Rho-family GTPase Cdc42. During cell polarization, Cdc42 is activated in a localized manner and induces downstream events, most importantly, the generation of localized actin cytoskeletal elements. The goal of this proposal is to understand how Cdc42 induces polarized polymerization of actin filaments. We will continue our ongoing work studying how actin filaments are nucleated at cell cortex and how Cdc42 defines the site of actin nucleation during cell polarization. We will also investigate the mechanism by which the activated form of Cdc42 drives the initial breakage of cell symmetry. The specific aims are: 1) Biochemical characterization of the Beel/Vrpl/myosin-I complex; 2) Studying the regulation of the Beel/Vrpl/myosin-I complex during cell polarization; 3) Understanding the mechanism by which the Arp2/3 complex nucleate actin polymerization; 4) Investigating the Intrinsic mechanism that drives cell polarity generation. PERFORMANCE SITE ========================================Section End===========================================