Molecular Control of Cell Proliferation

细胞增殖的分子控制

• 批准号: 7884703
• 负责人: DAVID Owen MORGAN
• 金额: $ 20.55万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-03 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7884703
• 关键词: Active Sites; Address; Behavior; Binding; Biochemical; Cell Cycle; Cell Proliferation; Cells; Cellular biology; Chromosome Segregation; Complex; Conserved Sequence; Deubiquitinating Enzyme; Development; Enzymatic Biochemistry; Enzymes; Eukaryotic Cell; Event; Genetic; Knowledge; Laboratory Study; Mitosis; Mitotic; Modification; Molecular; Molecular Genetics; Mutagenesis; Polyubiquitin; Polyubiquitination; Proteins; Research; Saccharomyces cerevisiae; Saccharomycetales; Staging; System; Ubiquitin-Conjugating Enzymes; Ubiquitin-Protein Ligase Complexes; Ubiquitination; Work; anaphase-promoting complex; base; fascinate; human disease; insight; multicatalytic endopeptidase complex; tumor progression; ubiquitin ligase; ubiquitin-protein ligase

DESCRIPTION (provided by applicant): This project will explore the regulatory system that governs progression through the stages of the eukaryotic cell division cycle, with an emphasis on the control of chromosome segregation in mitosis. The final events of mitosis are triggered by a poorly understood enzyme called the Anaphase-Promoting Complex or APC. The APC is a large, multisubunit ubiquitin ligase that catalyzes the ubiquitination of several key regulators of late mitotic events. In the proposed studies, biochemical and molecular genetic approaches will be used in the budding yeast Saccharomyces cerevisiae to dissect the enzymological mechanisms by which the APC, together with its various accessory components, recognizes its substrates and assembles polyubiquitin chains that direct those substrates to the proteasome for destruction. Three specific aims are proposed. The first aim focuses on the important question of how the APC recognizes its targets: mutagenesis and detailed biochemical analyses will be used to unveil the functions of three related APC subunits that contain a conserved sequence motif, the tetratricopeptide repeat or TPR, that forms a binding interface involved in substrate recruitment. The second aim centers on accessory enzymes that collaborate with the APC to help govern its function: recent studies from this laboratory have revealed that APC function depends on two ubiquitin-conjugating enzymes or E2s, and the proposed studies will explore the biochemical behavior of these two proteins. Additional work will address the function of a polyubiquitin chain-extending enzyme that was identified in preliminary studies as a potential collaborator of the APC. Finally, in the third aim, genetic and biochemical approaches will be used to understand how the ubiquitination state of APC targets is regulated by deubiquitinating enzymes in the cell. The knowledge gained from these studies will provide new insights into the control of chromosome segregation, errors in which often contribute to developmental problems and cancer progression. These studies are also likely to illuminate general mechanisms of protein ubiquitination, a regulatory modification of importance throughout cell biology and human disease.

描述（由申请人提供）：该项目将探索控制真核细胞分裂周期各阶段进展的调控系统，重点是有丝分裂中染色体分离的控制。有丝分裂的最终事件是由一种人们知之甚少的酶触发的，这种酶被称为后期促进复合物（APC）。 APC 是一种大型多亚基泛素连接酶，可催化晚期有丝分裂事件的几个关键调节因子的泛素化。在拟议的研究中，将在芽殖酵母酿酒酵母中使用生化和分子遗传学方法来剖析 APC 及其各种辅助成分识别其底物并组装将这些底物引导至蛋白酶体的多泛素链的酶学机制为了破坏。提出了三个具体目标。第一个目标集中于 APC 如何识别其靶标的重要问题：将使用诱变和详细的生化分析来揭示三个相关 APC 亚基的功能，这些亚基包含保守的序列基序、四三肽重复序列或 TPR，形成结合参与底物招募的界面。第二个目标集中于与 APC 合作帮助控制其功能的辅助酶：该实验室最近的研究表明 APC 功能依赖于两种泛素结合酶或 E2，拟议的研究将探索这两种酶的生化行为蛋白质。其他工作将解决多聚泛素扩链酶的功能，该酶在初步研究中被确定为 APC 的潜在合作者。最后，在第三个目标中，将使用遗传和生化方法来了解细胞中的去泛素化酶如何调节 APC 靶标的泛素化状态。从这些研究中获得的知识将为染色体分离的控制提供新的见解，其中的错误往往会导致发育问题和癌症进展。这些研究也有可能阐明蛋白质泛素化的一般机制，这是一种在细胞生物学和人类疾病中具有重要意义的调节修饰。