权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulation of Centrosome Assembly by Phosphorylation

磷酸化调节中心体组装

基本信息

批准号：
8811609
负责人：
Mi Hye Song
金额：
$ 21.17万
依托单位：
OAKLAND UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-05-10 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8811609
关键词：
Regulation Centrosome Assembly Phosphorylation

项目摘要

DESCRIPTION (provided by applicant): Centrosomes play a critical role in establishing bipolar spindles. For the fidelity of cell division centrosomes must duplicate precisely once per cell cycle. Errors in this process result in mis- segregation of chromosomes. Aberrant centrosomes are often associated with genomic instability, a feature of many cancers. The proposed research uses the C. elegans embryo as an in vivo model to perform genetics-phosphoproteomic analyses of centrosome assembly. Among 5 essential centrosome factors in C. elegans, SAS-5 plays a key role in the assembly of new centrosomes, and its functional homologs (Ana2 and SIL/STIL) are also required for mitotic spindle organization. A mutation in the putative human homolog (SIL/STIL) of SAS-5 is linked to primary microcephaly (MCPH), an autosomal- recessive congenital disorder with reduced brain size. While we realize the great impact of SAS-5 for cell division and brain development, the molecular and biochemical mechanisms by which SAS-5 regulates centrosome assembly remain elusive. Our long-term goal is to elucidate the molecular and genetic mechanisms of the centrosome assembly. The objective is to understand regulatory mechanism of SAS-5 in centrosome assembly. Proper levels of centrosome proteins (SAS-6, and Plk4/Sak) are critical for the correct number of centrosomes, which is regulated by proteasomal destruction. Recent work proposed that protein phosphatase 2A (PP2A) targets SAS-5 to regulate centrosome assembly. Our central hypothesis is that SAS-5 is regulated by PP2A-dependent phosphorylation, which directs SAS-5 to 26S proteasome to ensure its proper level and localization. Our rationale is that identifying the sites dephosphorylated by PP2A and defining their critical role will reveal how site-specific phosphorylation events contribute to the regulation of SAS-5 activity and the fidelity of the centrosome assembly. We plan to test our central hypothesis by pursuing the following two specific aims: 1) Identify all phosphorylation sites of SAS-5 and specify the sites that are targeted by protein phosphatase 2A (PP2A). 2) Determine the biological impact of site-specific phosphorylation on SAS-5 in centrosome assembly. Toward these aims, we will use genetics, biochemistry, high- resolution imaging, and phosphoproteomics. We expect to identify phosphorylation sites of SAS-5 and their physiological roles responsible for proper activity of SAS-5 in centrosome assembly. The proposed research is significant, because understanding the mechanisms of centrosome assembly will likely provide insight relevant to the diagnosis and treatment of human diseases such as cancers and ciliopathies that are associated with centrioles/basal bodies, in addition to fundamentally advancing the field of centrosome biology. PUBLIC HEALTH RELEVANCE: The proposed research is relevant to public health because the molecular and biochemical mechanisms of regulated levels of centrosome proteins in C. elegans are expected to enhance our knowledge of centrosome regulation in human diseases with broad and important healthcare ramifications related to cancers and ciliopathies. Thus, the proposed research is relevant to the part of NIH's mission that pertains to developing knowledge that will help developing diagnostic and therapeutic inventions for human diseases.

描述（由申请人提供）：中心体在建立双极纺锤体中起关键作用。为了细胞分裂的精确性，中心体必须在每个细胞周期精确复制一次。这一过程中的错误导致染色体的错误分离.异常中心体通常与基因组不稳定性相关，这是许多癌症的特征。本研究采用C.线虫胚胎作为体内模型进行中心体组装的遗传学-磷酸蛋白质组学分析。在C.在线虫中，SAS-5在新中心体的组装中起关键作用，并且其功能同源物（Ana 2和SIL/STIL）也是有丝分裂纺锤体组织所必需的。SAS-5的假定人类同源物（SIL/STIL）中的突变与原发性小头畸形（MCPH）相关，MCPH是一种常染色体隐性遗传的先天性疾病，具有减小的脑尺寸。虽然我们认识到SAS-5对细胞分裂和脑发育的巨大影响，但SAS-5调节中心体组装的分子和生化机制仍然是难以捉摸的。我们的长期目标是阐明中心体组装的分子和遗传机制。目的是了解SAS-5在中心体组装中的调控机制。中心体蛋白（SAS-6和Plk 4/Sak）的适当水平对于中心体的正确数量至关重要，这是由蛋白酶体破坏调节的。最近的工作提出蛋白磷酸酶2A（PP 2A）靶向SAS-5调节中心体组装。我们的中心假设是，SAS-5是由PP 2A依赖的磷酸化，指导SAS-5的26 S蛋白酶体，以确保其适当的水平和定位。我们的基本原理是，识别由PP 2A去磷酸化的位点并定义其关键作用将揭示位点特异性磷酸化事件如何有助于调节SAS-5活性和中心体组装的保真度。我们计划通过追求以下两个具体目标来测试我们的中心假设：1）鉴定SAS-5的所有磷酸化位点并指定蛋白磷酸酶2A（PP 2A）靶向的位点。2)确定中心体组装中SAS-5位点特异性磷酸化的生物学影响。为了达到这些目标，我们将使用遗传学，生物化学，高分辨率成像和磷酸化蛋白质组学.我们希望确定SAS-5的磷酸化位点和它们在中心体组装中的生理作用。拟议的研究是重要的，因为了解中心体组装的机制将可能提供与诊断和治疗人类疾病相关的见解，如与中心粒/基体相关的癌症和纤毛病，除了从根本上推进中心体生物学领域。公共卫生相关性：这项研究与公共卫生有关，因为C.秀丽隐杆线虫有望增强我们对人类疾病中中心体调节的认识，其具有与癌症和纤毛病相关的广泛且重要的医疗分支。因此，拟议的研究与NIH的使命的一部分有关，该使命涉及开发有助于开发人类疾病诊断和治疗发明的知识。