Regulating centrosome homeostasis through the UPS

项目总结/摘要 泛素介导的蛋白水解调节许多蛋白质的降解，从而 控制许多细胞过程，包括细胞周期进程，信号转导， 途径、分化和中心体复制周期。很多细节 泛素化过程中固有的一种酶是由E3泛素连接酶介导的， 选择性地结合并募集所选择的底物至泛素缀合酶。值得注意的是， 大多数泛素连接酶被认为是“孤儿”，因为它们的底物还没有 被识别。几种泛素连接酶定位于中心体，并控制蛋白质的表达。 关键中心粒复制因子的泛素化和随后的蛋白酶体降解， 如CP 110、PLK 4和SAS 6（分别通过SCF-Cyclin F、SCF-βTrCP和APC/C-Cdh 1）。 此外，泛素连接酶还控制其他中心体功能，如中心粒 分离（通过SCF-β TrCP介导的Cep 68降解）。我们的初步结果 显示了另外“孤儿”E3连接酶复合物位于中心体， 在细胞的特定时期，中心体蛋白被泛素系统降解 周期我们提出了一个系统地探索中心体周期调节的项目， 泛素-蛋白酶体系统我们将使用蛋白质组学技术来鉴定新的 底物的中心体E3连接酶（特异性AIM 1），并将验证和生物化学 表征在AIM 1下鉴定的最具生物学意义的底物（特异性AIM 2）。 我们将对E3泛素连接酶和中心体相互作用物进行分析， 网络可访问资源。中心体扩增是大多数人的共同特征。 癌症，并可能导致染色体不稳定。此外，中心体异常是 也与神经元和细胞纤毛的遗传疾病有关。因此，信息 从拟议的研究中获得的预期将直接关系到我们对 癌症生物学和其他人类疾病，如纤毛病和神经元发育 紊乱

PROJECT SUMMARY/ABSTRACT Ubiquitin-mediated proteolysis regulates the degradation of numerous proteins, thereby controlling many cellular processes, including cell cycle progression, signal transduction pathways, differentiation, and the centrosome duplication cycle. Much of the specificity inherent in the ubiquitination process is mediated by the E3 ubiquitin ligases, which bind selectively to, and recruit, the chosen substrate to the ubiquitin-conjugating enzyme. Notably, the majority of ubiquitin ligases are considered “orphan”, because their substrates have not yet been identified. Several ubiquitin ligases localize to the centrosome and control the ubiquitination and subsequent proteasomal degradation of critical centriole duplication factors, such as CP110, PLK4, and SAS6 (by SCF-Cyclin F, SCF-βTrCP, and APC/C-Cdh1, respectively). Furthermore, ubiquitin ligases also control additional centrosomal functions, such as centriole separation (through the SCF-βTrCP-mediated degradation of Cep68). Our preliminary results show that additional “orphan” E3 ligase complexes reside at the centrosome, and that several centrosomal proteins are degraded by the ubiquitin system during specific phases of the cell cycle. We propose a project systematically exploring the regulation of the centrosome cycle by the ubiquitin-proteasome system. We will use proteomic techniques to identify novel substrates of centrosomal E3 ligases (specific AIM 1) and will validate and biochemically characterize the most biologically significant substrates identified under AIM 1 (specific AIM 2). We will make our analysis of E3 ubiquitin ligases and centrosome interactors available as a web-accessible resource. Centrosome amplification is a common feature of the large majority of cancers and can result in chromosome instability. Furthermore, centrosome abnormalities are also associated with genetic disorders of neurons and cellular cilia. Therefore, the information gained from the proposed studies is expected to be of direct relevance to our understanding of cancer biology and other human diseases such as ciliopathies and neuronal development disorders.