Regulatory Enzymes and Systems in Cell Cycle Control

细胞周期控制中的调节酶和系统

• 批准号: 10425467
• 负责人: DAVID Owen MORGAN
• 金额: $ 94.55万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2026-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10425467
• 关键词: Address; Affinity; Binding; Biochemical; Cancer Etiology; Cell Cycle; Cell Cycle Progression; Cell Cycle Regulation; Cell division; Cells; Cellular biology; Chromosome Segregation; Chromosomes; Complex; Cyclic AMP-Dependent Protein Kinases; Cyclin-Dependent Kinases; Cyclins; Cytokinesis; Defect; Development; Disease; Enzymes; Eukaryotic Cell; Event; Gene Expression; Genetic; Genetic Transcription; Human; Investigation; Malignant Neoplasms; Measurement; Mediating; Mitosis; Mitotic spindle; PTTG1 gene; Phosphorylation Site; Process; Protease Inhibitor; Proteins; Research; S phase; Saccharomycetales; Substrate Interaction; System; Variant; Work; anaphase-promoting complex; base; chaperonin; cohesin; daughter cell; event cycle; fascinate; genetic regulatory protein; human disease; information processing; insight; separase; single molecule; tumor progression; ubiquitin ligase

PROJECT SUMMARY/ABSTRACT The proposed research explores the fascinating regulatory system that governs the eukaryotic cell division cycle. The cell-cycle control system is based on master regulatory enzymes that include the cyclin-dependent protein kinases (Cdks) and a ubiquitin ligase called the anaphase-promoting complex or cyclosome (APC/C). As the cell progresses through the steps of cell division, sequential Cdk-cyclin complexes modify hundreds of proteins, leading to chromosome duplication in S phase and alignment of duplicated chromosome on the mitotic spindle in M phase. The APC/C then triggers destruction of several key regulators, unleashing the dramatic events of chromosome segregation and cytokinesis. One critical APC/C substrate is securin, an inhibitor of the protease, separase; APC/C-mediated securin destruction releases separase to cleave the cohesin complex holding duplicated chromosomes together. The precise timing of cell cycle events requires that Cdks and the APC/C are activated and modify their targets in a specific order. The biochemical mechanisms underlying this order are the central focus of the research described in this application. The work will explore a diverse array of interesting mechanistic problems in Cdk and APC/C function. Studies in budding yeast will address the complex information processing that can be achieved through multi-site phosphorylation of Cdk substrates, focusing on transcriptional regulators that govern cyclin gene expression. Multiple lines of investigation will address the mechanisms by which the APC/C, together with its substrate-binding activator subunit, controls the destruction of specific targets. A newly developed single-molecule approach will provide rigorous quantitative measurements of APC/C-substrate interactions, providing insight into the variations in substrate affinity that underlie the ordering of cell cycle events. Biochemical and structural approaches with human proteins will be used to unravel the mechanisms by which the APC/C activator subunit is loaded onto the APC/C by the chaperonin TRiC/CCT. Similar approaches will be used to determine the mechanisms by which human separase recognizes its substrates, and the mechanisms by which securin and other regulatory proteins inhibit separase catalytic function. The information gained from these studies will provide important new insights into the control of cell-cycle progression, and will thereby enhance our understanding of diseases, such as cancer, in which cell-cycle control or chromosome segregation is defective. These studies will also illuminate general regulatory mechanisms of major importance throughout cell biology and human disease.

项目概要/摘要 拟议的研究探索了控制真核细胞分裂的迷人调节系统 循环。细胞周期控制系统基于主调节酶，其中包括细胞周期蛋白依赖性酶 蛋白激酶 (Cdks) 和称为后期促进复合物或环体 (APC/C) 的泛素连接酶。 随着细胞进行细胞分裂的步骤，连续的 Cdk-细胞周期蛋白复合物会修改数百个 蛋白质，导致 S 期染色体复制以及复制染色体在 S 期的排列 有丝分裂纺锤体处于M期。然后，APC/C 会触发几个关键调节器的破坏，释放出 染色体分离和胞质分裂的戏剧性事件。一种重要的 APC/C 底物是 securin，一种 蛋白酶、分离酶的抑制剂； APC/C 介导的 securin 破坏释放分离酶以裂解 将复制的染色体固定在一起的粘连蛋白复合物。细胞周期事件的精确计时需要 Cdks 和 APC/C 被激活并按特定顺序修改其目标。生化 该顺序背后的机制是本申请中描述的研究的中心焦点。工作 将探索 Cdk 和 APC/C 功能中各种有趣的机制问题。研究处于萌芽状态 酵母将解决可通过多位点磷酸化实现的复杂信息处理 Cdk 底物，重点关注控制细胞周期蛋白基因表达的转录调节因子。多行 调查将解决 APC/C 及其底物结合激活剂的机制 子单元，控制特定目标的破坏。新开发的单分子方法将提供 APC/C 底物相互作用的严格定量测量，提供对 APC/C 底物相互作用变化的深入了解 底物亲和力是细胞周期事件排序的基础。生物化学和结构方法 人类蛋白质将被用来解开 APC/C 激活子亚基加载的机制 APC/C 由伴侣蛋白 TRiC/CCT 控制。将使用类似的方法来确定机制 人类分离酶识别其底物的机制，以及 securin 和其他调节蛋白的机制 蛋白质抑制分离酶催化功能。从这些研究中获得的信息将提供重要的 对细胞周期进程控制的新见解，从而增强我们对疾病的理解， 例如细胞周期控制或染色体分离有缺陷的癌症。这些研究也将 阐明在整个细胞生物学和人类疾病中具有重要意义的一般调节机制。