CENTROSOME PROTEIN PERICENTRIN

这项工作的长期目标是开发一种分子 了解中心体组织微管的过程。 微管的空间取向对于它们的功能至关重要， 是由中心体控制的中心体已经被转移到 调查，因此其功能和调节的基础是未知的。我们 发现了一种高度保守的中心体蛋白，叫做中心周蛋白 这是细胞分裂和微管组织所必需的 细胞骨架Pericentrin为我们提供了独特的机会， 在分子水平上理解中心体的功能。最近的进展， 我们的实验室表明，我们将能够识别和重组 成核的成分。我们现在处于一个非常有利的位置： 1.检验中心周围蛋白参与中心体组装的假设 并定义功能的顺序要求。 2.测试假设，即pericentrin组装到中心体上， 细胞周期特异性磷酸化依赖方式。 3.检验中心周蛋白结合蛋白参与 微管成核 在实现这一建议的目标方面取得了重大进展。我们 已经产生了阻断中心周围蛋白功能的抗体，产生了突变体， 野生型pericentrin cDNA和融合蛋白，并开发了一种新的 用于重建中心体功能的体外测定。由于第一 在提交该提案时，我们鉴定了围中心蛋白结合伴侣， 干扰中心体结构使用突变pericentrin，并提出了 值得注意的观察是，中心膜抗体-珠粒促进 微管这些最新的进展，分子工具和分析将 使我们能够在理解其性质方面取得快速进展， 中心体和中心体的功能。理解 中心体功能很重要，原因有几个。作为主办方 微管细胞骨架，中心体是许多细胞中的关键角色。 基本的细胞过程鉴于其在大会中的重要性， 在细胞分裂过程中，中心体是一个潜在的有丝分裂纺锤体。 细胞生长的调节剂和形态发生的协调者。中心体- 介导的微管极性是组织细胞质的关键， 胞内囊泡运输和细胞器定位。尽管 它在微管焦点的中心位置及其在 对中心体的了解很少。我们的初步 结果表明，pericentrin将使我们能够使重要的 在生物学领域的贡献一直很难研究。我们 对实现我们长期目标的未来前景感到特别兴奋， 体外重建个体中心体功能的目的 件.

The long term objective of this work is to develop a molecular understanding of the process by which centrosomes organize microtubules. The spatial orientation of microtubules is crucial for their function and is controlled by the centrosome. The centrosome has been recalcitrant to investigation so the basis for its function and regulation are unknown. We have discovered a highly conserved centrosome protein called pericentrin that is essential for cell division and organization of the microtubule cytoskeleton. Pericentrin provides us with a unique opportunity to understand centrosome function at the molecular level. A recent advance in our laboratory suggests that we will be able to identify and reconstitute the components of nucleation. We are now in an excellent position to: 1. Test the hypothesis that pericentrin is involved in centrosome assembly and define the sequence requirements for function. 2. Test the hypothesis that pericentrin assembles onto centrosomes in a cell cycle-specific phosphorylation-dependent manner. 3. Test the hypothesis that pericentrin binding proteins are involved in microtuble nucleation. Significant progress has been made toward th goals of this proposal. We have raised antibodies that block pericentrin function, produced mutant and wild type pericentrin cDNAs and fusion proteins and developed a novel in vitro assay for reconstituting centrosome function. Since that first submission of this proposal, we identified a pericentrin binding partner, perturbed centrosome structure using mutant pericentrin, and made the remarkable observation that pericentrin antibody-beads promote assembly of microtubules. These recent advances, molecular tools, and assays will allow us to make rapid progress in understanding the properties and function of pericentrin and centrosomes in general. Understanding centrosome function is important for several reasons. As the organizer of the microtubule cytoskeleton, the centrosome is a pivotal player in many fundamental cellular processes. Given its importance in the assembly of the mitotic spindle during cell division, the centrosome is a potential regulator of cell growth and a coordinator of morphogenesis. Centrosome- mediated microtubule polarity is critical for organizing the cytoplasm for intracellular vesicular transport and positioning of organelles. Despite its central position at the focus of microtubules and its central role in the life of a cell, the centrosome is poorly understood. Our preliminary results suggest that pericentrin will allow us to make important contributions in an area of biology that has been difficult to study. We are especially excited about the future prospect of realizing our long term goal of reconstituting centrosome function in vitro from individual components.