Coupling Cell Cycle Progression to Cell Morphogenesis

描述（由申请人提供）：脓蛋白是 GTP 结合和丝状形成蛋白，广泛存在于从酵母到人类的真核细胞谱系中。脓蛋白参与细胞膜和细胞骨架结构重塑的细胞过程，特别是在细胞分裂和胞质分裂过程中。在芽殖酵母（酿酒酵母）中，septin 丝组装在协调细胞周期事件中发挥着重要作用，部分是通过在母细胞与其子细胞之间的发育界面（芽颈）处建立用于招募和相互作用众多蛋白激酶的支架。 Hsl1 是 AMPK 相关蛋白激酶家族的成员，位于芽颈，整体参与耦合 septin 项圈组装与进入 M 期的许可。该提案描述了解决目前人们知之甚少的 Hsl1 介导信号传导的三个领域的实验方法：（1）Hsl1 激活需要哪些因素？ (2) Hsl1 介导的新靶点和既定靶点的磷酸化在检查点退出过程中发挥什么作用？ (3) HsM 的泛素相关结构域 (DBA) 在其活性、定位和/或稳定性方面发挥什么作用？

DESCRIPTION (provided by applicant): Septins are GTP-binding and filament-forming proteins found ubiquitously in the eukaryotic lineage that spans from yeasts to humans. Septins participate in cellular processes that involve remodeling of membranes and cytoskeletal structures, especially during cell division and cytokinesis. In budding yeast (Saccharomyces cerevisiae), septin filament assembly serves a prominent role in coordinating cell cycle events, in part, by establishing a scaffold for recruitment and interaction of numerous protein kinases at the developing interface (bud neck) between a mother cell and its daughter cell. Hsl1, a member of the family of AMPK-related protein kinases, is located at the bud neck and is integrally involved in coupling septin collar assembly to licensing of entry into M phase. This proposal describes experimental approaches to address three areas of Hsl1-mediated signaling that are currently poorly understood: (1) What factors are necessary for Hsl1 activation? (2) What role does Hsl1-mediated phosphorylation of new and established targets play in exit from the checkpoint? (3) What function does the ubiquitin-associated domain (DBA) of HsM play in its activity, localization, and/or stability?