Proteolytic Regulation of Centrosome Assembly

中心体组装的蛋白水解调节

• 批准号: 10515144
• 负责人: Mi Hye Song
• 金额: $ 45万
• 依托单位: OAKLAND UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10515144
• 关键词: 26S proteasome; Affect; Binding; Biochemical; Biological Models; Biology; Brain; CRISPR/Cas technology; Caenorhabditis elegans; Cell Cycle; Cell division; Centrioles; Centrosome; Complex; Defect; Development; Diagnostic; Disease; Embryo; Ensure; Exhibits; Genetic; Genomic Instability; Goals; Healthcare; Homeostasis; Human; Knowledge; Malignant Neoplasms; Mediating; Microcephaly; Microtubule-Organizing Center; Mission; Modeling; Mus; Mutation; Predisposition; Principal Investigator; Proteins; Proteolysis; Public Health; Quantitative Microscopy; Regulation of Proteolysis; Research; Role; Site; System; Testing; Therapeutic; Therapeutic Intervention; United States National Institutes of Health; Wolves; Work; anaphase-promoting complex; base; ciliopathy; cofactor; daughter cell; genome editing; genome integrity; human disease; in vivo; in vivo Model; invention; mutant; nano; programs; recruit; transmission process; tumorigenesis; ubiquitin ligase; ubiquitin-protein ligase

Program Director/Principal Investigator (Last, First, Middle): Song, Mi Hye Summary Centrosomes, as the primary microtubule-organizing center, establish bipolar spindles that ensure accurate transmission of genetic contents into two daughter cells. To maintain genomic integrity, centrosome number must be strictly regulated by duplicating only once per cell cycle. Abnormal centrosomes are associated with human disorders, including cancers, microcephaly and other developmental defects. Our long-term goal is to understand the genetic mechanisms of centrosome function and assembly using the early C. elegans embryo as an in vivo model. The overall objective is to investigate how the ubiquitin ligase, anaphase promoting complex/cyclosome (APC/C) and the coactivator FZR-1 (Cdh1 in human), contributes to centrosome assembly through proteasomal degradation of centrosome factors. FZR-1/Cdh1 (an APC/C cofactor) confers a substrate- binding through recognizing highly conserved degron motifs (KEN- and D-boxes). Cdh1-deficient mice exhibit embryonic lethality, genomic instability, and higher susceptibility to tumorigenesis and defective brain development. The abundance of centrosome components directly influences centrosome number: Blocking degradation of centrosome factors causes extra centrosomes, while depletion inhibits centrosome duplication. While we realize the great impact of the APC/C complex for regulating levels of centrosome factors, its substrate repertoire and regulatory mechanisms remain elusive. We propose to investigate SAS-7 as a potential substrate of APC/CFZR-1: SAS-7 functions most upstream in centrosome assembly and SAS-7 protein contains conserved degron motifs at multiple sites. We hypothesize that SAS-7 is another centrosome factor that is directly targeted APC/CFZR-1. Inhibiting APC/CFZR-1 blocks SAS-7 degradation, leading to hyper-stabilization of SAS-7 and compensating for a partial loss of ZYG-1 function in zyg-1 mutants. Our rationale is that its substrate repertoire of APC/CFZR-1 in centrosome assembly and defining their role will reveal the regulatory mechanisms of APC/CFZR-1 required for the fidelity of cell division. The aims of the project are to (1) determine if SAS-7 levels are affected by APC/CFZR-1-dependent proteolysis, (2) identify functional degron motifs within SAS-7, mediating APC/CFZR-1 targeting, and (3) understand how APC/CFZR-1-dependent proteolytic regulation of SAS-7 contributes to centrosome assembly and function. The use of in vivo-based genetics in a model system C. elegans will lay the groundwork for understanding human systems. The proposed project should contribute to advances in fundamental understandings of centrosome biology in humans and therapeutic interventions for human diseases and conditions such as cancers and microcephaly associated with abnormal centrosomes.

项目总监/首席调查员(最后、第一、中间)：宋美惠 摘要 中心体作为主要的微管组织中心，建立了两极纺锤体，确保了 将基因内容传递到两个子细胞中。为了保持基因组的完整性，中心体数量 必须严格控制，每个细胞周期只复制一次。中心体异常与 人类疾病，包括癌症、小头畸形和其他发育缺陷。我们的长期目标是 利用线虫早期胚胎了解中心体功能和组装的遗传机制 作为活体模型。总的目标是调查泛素连接酶，后期促进 复合体/环体(APC/C)和共活化子FZR-1(人体中的CDH1)参与中心体组装 通过蛋白酶体对中心体因子的降解。FZR-1/CDH1(一种APC/C辅因子)赋予底物- 通过识别高度保守的退化基序(KN-盒和D-盒)进行结合。CDH1缺陷小鼠表现出 胚胎致死性、基因组不稳定、肿瘤发生和脑缺陷的易感性更高 发展。中心体成分的丰度直接影响中心体的数量：阻断 中心体因子的降解导致额外的中心体，而耗竭则抑制中心体复制。 虽然我们意识到APC/C复合体对调节中心体因子水平的巨大影响，但它的底物 曲目和监管机制仍然难以捉摸。我们建议研究SAS-7作为一种潜在的底物 APC/CFZR-1：SAS-7在中心体组装中的上游功能最强，SAS-7蛋白含有保守的 多个地点都有退化的图案。我们假设SAS-7是另一个直接 目标是APC/CFZR-1。抑制APC/CFZR-1阻止SAS-7降解，导致SAS-7超稳定 以及补偿Zyg-1突变体中Zyg-1功能的部分丧失。我们的理论基础是它的底物 APC/CFZR-1在中心体组装中的谱系及其作用的确定将揭示其调控机制 细胞分裂的保真度所需的APC/CFZR-1。该项目的目标是(1)确定SAS-7水平 受APC/CFZR-1依赖的蛋白分解的影响，(2)鉴定SAS-7中的功能降解基序，介导 APC/CFZR-1靶向，以及(3)了解APC/CFZR-1依赖的SAS-7蛋白水解性调节 有助于中心体的组装和功能。基于活体的遗传学在模型系统C. 优雅将为理解人类系统奠定基础。拟议的项目应有助于 人类中心体生物学的基本认识及治疗干预研究进展 与异常中心体有关的人类疾病和状况，如癌症和小头畸形。