Regulation of formins and cell polarity

 描述(申请人提供)：这项研究的目标是确定肌动蛋白细胞骨架的组装动力学和结构是如何由福尔马林控制的，以及调节它们活动的细胞机制。我们正在萌芽中的酵母中研究这个问题，在那里，福尔马林组装具有特定长度、结构和动力学的肌动蛋白电缆，这是极化细胞生长所必需的。此外，我们将这一工作扩展到哺乳动物的Forin调控。该提案侧重于在前一个资金周期中发现的几种新的多组分机制，这些机制控制着Forin介导的肌动蛋白成核，或Forin介导的肌动蛋白细丝伸长事件的持续时间和速度。该项目结合了遗传学、活细胞成像、生物化学和新型多波长单分子TIRF显微镜。其目的是：(1)检验关于Form in介导的肌动蛋白电缆成核在空间和时间上受Bud6、profilin、Tpm1和Tpm2组合效应控制的假说；(2)检验关于肌动蛋白电缆的长度、速度和结构受涉及Forin、Bud14-Kel1-Kel2复合体、帽蛋白和Smy1的细丝带刺末端动态相互作用控制的假说；以及(3)检验人类CLIP-170与mDia1相互作用形成新型带刺末端跟踪复合体的假设，该复合体支持体外和体内超快的肌动蛋白细丝伸长。

 DESCRIPTION (provided by applicant): The goal of this research is to determine how the assembly dynamics and architecture of the actin cytoskeleton are controlled by formins and the cellular mechanisms regulating their activities. We are studying this question in budding yeast, where formins assemble actin cables of a characteristic length, architecture, and dynamics required for polarized cell growth. Further, we extend this work to mammalian formin regulation. The proposal focuses on several new multi-component mechanisms discovered during the previous funding cycle, which control formin-mediated actin nucleation, or the duration and speed of formin-mediated actin filament elongation events. The project combines genetics, live- cell imaging, biochemistry, and novel multi-wavelength single molecule TIRF microscopy. The Aims are: (1) Test the hypothesis that formin-mediated actin cable nucleation is spatially and temporally controlled by the combinatorial effects of Bud6, profilin, Tpm1, and Tpm2; (2) Test the hypothesis that actin cable length, velocity, and architecture are controlled by dynamic interplay at filament barbed ends involving formins, Bud14-Kel1-Kel2 complex, capping protein, and Smy1; and (3) Test the hypothesis that human CLIP-170 interacts with mDia1 to form a novel barbed end- tracking complex that supports ultrafast actin filament elongation in vitro and in vivo.