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/首席研究员（后、前、中）：Song、Mi Hye 概括 中心体作为主要的微管组织中心，建立双极纺锤体，确保准确的 将遗传内容传递到两个子细胞中。为了保持基因组完整性，中心体数量 必须通过每个细胞周期仅复制一次来严格调节。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 使用早期秀丽隐杆线虫胚胎了解中心体功能和组装的遗传机制 作为体内模型。总体目标是研究泛素连接酶如何促进后期 复合体/环体 (APC/C) 和共激活子 FZR-1（人体内的 Cdh1），有助于中心体组装 通过中心体因子的蛋白酶体降解。 FZR-1/Cdh1（APC/C 辅因子）赋予底物- 通过识别高度保守的降解决定子基序（KEN-和D-盒）进行结合。 Cdh1缺陷小鼠表现 胚胎致死率、基因组不稳定性以及对肿瘤发生和大脑缺陷的更高易感性 发展。中心体成分的丰度直接影响中心体的数量：阻塞 中心体因子的降解会导致中心体额外，而耗尽会抑制中心体复制。 虽然我们认识到 APC/C 复合物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 作为潜在的底物 APC/CFZR-1：SAS-7 在中心体组装的最上游发挥作用，SAS-7 蛋白包含保守的 多个位点的降解决定子基序。我们假设 SAS-7 是另一个直接影响中心体的因子 目标为 APC/CFZR-1。抑制 APC/CFZR-1 可阻止 SAS-7 降解，从而导致 SAS-7 超稳定 并补偿 zyg-1 突变体中 ZYG-1 功能的部分丧失。我们的理由是它的底物 APC/CFZR-1 在中心体组装中的全部功能并定义其作用将揭示调控机制 细胞分裂保真度所需的 APC/CFZR-1。该项目的目标是 (1) 确定 SAS-7 级别是否 受 APC/CFZR-1 依赖性蛋白水解作用的影响，(2) 识别 SAS-7 内的功能降解决定子基序，介导 APC/CFZR-1 靶向，以及 (3) 了解 APC/CFZR-1 依赖性蛋白水解调节 SAS-7 有助于中心体的组装和功能。在模型系统中使用基于体内的遗传学 C. 线虫将为理解人类系统奠定基础。拟议的项目应有助于 对人类中心体生物学的基本理解和治疗干预的进展 与异常中心体相关的人类疾病和病症，例如癌症和小头畸形。