MOLECULAR ANALYSIS OF THE YEAST ACTIN CYTOSKELETON

描述：在酵母细胞周期中，肌动蛋白的分布发生变化 以一种高度具体的方式反映增长的局部变化， 发生在这段时间。 然而，很少有人知道， 肌动蛋白定位和生长的改变是介导或调节的。 肌动蛋白结合蛋白可能很重要，因为缺乏这些蛋白的突变体 蛋白质在这些过程中有缺陷。 然而，尽管事实上， 这些蛋白质中的许多已经被很好地生物化学表征， 已知的各种肌动蛋白结合蛋白的活动， 影响肌动蛋白的组织和生长。 私家侦探正专注于 肌动蛋白丝交联蛋白fimplant（Sac 6），这是唯一的 酵母中已知的肌动蛋白丝交联蛋白。 肌动蛋白交联 纤维对于肌动蛋白的许多功能可能是必需的， 单独的细丝不能承受强的压缩力。 然而，很少有人知道的作用，调节交联 在酵母或其他细胞中。 在这份补助金中，P.I.建议确定 Sac 6在肌动蛋白-丝交联中的作用及其可能的调控。 特别是，P.I.将首先研究 肌动蛋白丝交联。 私家侦探会问这两个行动是否 Sac 6的结合结构域与肌动蛋白上的相同或不同位点结合。 第二，PI。将决定Sac 6是否受到监管或在以下方面发挥作用： 细胞周期的特定阶段。 第三，P.I.将使用基因筛选 为了鉴定揭示Sac 6在细胞凋亡中的调节或作用的蛋白质， cell. 这些筛选将涉及寻找抑制的致命性 由Sac 6的过表达或Sac 6 -19突变体的表达引起， 它能与肌动蛋白紧密结合

DESCRIPTION: During the yeast cell cycle, the distribution of actin changes in a highly specific way that reflects the changes in localization of growth that occur during this time. However, little is known of how the alterations in actin localization and growth are mediated or regulated. Actin-binding proteins are likely important, as mutants lacking these proteins are defective in these processes. However, despite the fact that many of these proteins have been well characterized biochemically, little is known of how the the activities of the various actin-biinding proteins in vitro affect actin organization and growth in vivo. The P.I. is focusing on the actin-filament cross-linking protein fimbrin (Sac6), which is the only actin-filament cross-linking protein known in yeast. Cross-linking of actin filaments is likely essential for many of the functions of actin, as individual filaments are unable to withstand strong compressional forces. However, little is known of either the roles of regulation of cross-linking in yeast or in other cells. In this grant, the P.I. proposes to identify the roles and possible regulation of actin-filament corss-linking by Sac6. In particular, the P.I. will first examine the molecular architecture of actin-filament cross-linking. The P.I. will ask whether the two actin binding domains of Sac6 bind to the same or different sites on actin. Second, the P.I. will determine whether Sac6 is regulated or has roles at specific stages of the cell cycle. Third, the P.I. will use genetic screens to identify proteins that reveal the regulation or roles of Sac6 in the cell. These screen will involve looking for suppression of the lethality caused by over-expression of Sac6, or expression of the Sac6-19 mutant, which binds actin extra-tightly.