Cell Polarity and Spindle Position

描述(申请人提供)：这个项目的目标是全面了解导致有丝分裂纺锤体在萌芽酵母中定位的分子机制。这一过程是许多细胞类型不对称分裂和发育的基础。纺锤体定位涉及星形微管(MT)与细胞皮质上极化位置的相互作用。在许多情况下，这一过程还需要肌动蛋白细胞骨架。MT在细胞皮质的捕获与在动粒中心的MT捕获有相似之处，一些蛋白质显然参与了这两个过程。因此，了解纺锤体定位的机制也可能对维持基因组的稳定性产生影响。因此，我们的研究解决了通过对发展和癌症的影响而影响人类健康的机制。我们的方法利用了遗传、生化和成像实验。它还受益于我们最近解决的系统组件之一BNIL FH2域的结构。在我们以前工作的基础上，我们研究了与MTS的正端相关的蛋白质和涉及的蛋白质，以及纺锤体定位所需的肌动蛋白组装的各个方面，我们建议进行以下实验：目的1：如何产生定位纺锤体前期纺锤体的力？目的2：动力蛋白是如何作用于其作用部位的，动力蛋白活性是如何被调节的？目的3：肌动蛋白依赖的肌动蛋白组装在体内是如何调节的？

DESCRIPTION (provided by applicant): The goal of this project is to comprehensively understand the molecular mechanisms leading to the positioning of the mitotic spindle in the budding yeast Saccaromyces cerevisiae. This process underlies asymmetric cell division and development in many cell types. Spindle positioning involves the interaction of astral microtubules (MTs) with polarized sites on the cell cortex. In many cases, this process also requires the actin cytoskeleton. The capture of MT at the cell cortex shares similarities with the capture of MTs at the kinetochore and some proteins are clearly involved in both processes. Thus, understanding mechanisms for spindle positioning may also impact upon the maintenance of genome stability. Our studies therefore address mechanisms that impact on human health through implications for development and cancer. Our approach utilizes genetic, biochemical, and imaging experiments. It also benefits from our recently solved structure of one component of the system, the Bnil FH2 domain. Building on our previous work to characterize proteins associated with the plus ends of MTs and proteins involved and aspects of actin assembly that are required for spindle orientation we propose experiments with the following aims: Aim1: How is the force generated to orient preanaphase spindles? Aim 2: How is dynein targeted to its site of action and how is dynein activity regulated? Aim 3: How is formin-dependent actin assembly regulated in vivo?