Coupling Cell Cycle Progression to Cell Morphogenesis

描述(申请人提供)：Septins是一种结合GTP和形成细丝的蛋白质，广泛存在于从酵母到人类的真核生物谱系中。Septins参与细胞过程，包括膜和细胞骨架结构的重塑，特别是在细胞分裂和胞质分裂期间。在萌芽酵母(Saccharmyces Cerevisiae)中，Septin细丝组装在协调细胞周期事件中起着重要作用，部分原因是通过在母细胞和子细胞之间的发育界面(芽颈)建立一个支架，用于招募和相互作用大量的蛋白激酶。Hsl1是AMPK相关蛋白激酶家族的成员之一，位于芽颈，参与连接间隔素环组装和进入M期的许可。这项建议描述了解决HSL1介导的信号转导的三个目前知之甚少的领域的实验方法：(1)HSL1激活所必需的因素？(2)HSL1介导的新的和已建立的靶点的磷酸化在退出检查点时起什么作用？(3)HSM的泛素相关结构域(DBA)在其活性、定位和/或稳定性中起什么作用？

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?