Anaphase Promoting Complex-mediated Proteolysis

后期促进复合物介导的蛋白水解

• 批准号: 7161467
• 负责人: MARK J SOLOMON
• 金额: $ 34.13万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7161467
• 关键词: Adenomatous Polyposis Coli Protein; Binding; Boxing; Cell Cycle; Cell Proliferation; Cell division; Cells; Chromosomes; Complex; Cyclins; Disease; Event; Genetic Screening; Goals; Human; Immunoblotting; Malignant Neoplasms; Mediating; Mitosis; Mitotic spindle; Modeling; Molecular Conformation; Normal Cell; Numbers; Pathway interactions; Phase; Phosphorylation; Process; Protein Overexpression; Proteins; Proteolysis; Research Personnel; Role; Saccharomycetales; System; Testing; Ubiquitin; Ubiquitination; Work; Yeasts; anaphase-promoting complex; insight; man; novel; prevent; programs; research study

DESCRIPTION (provided by applicant): A key event in the progression through and exit from mitosis is the ubiquitin-dependent degradation of cyclins and other key proteins by the Anaphase Promoting Complex (APC; also called the cyclosome). APC substrates contain degradation motifs such as the Destruction Box and the KEN Box that are required for their ubiquitination and for their binding to the APC activators, Cdc20 and Cdh1. Both motifs are required for efficient degradation, but either one alone suffices for binding to Cdh1p. We have proposed a pathway for the assembly of the APC-Cdh1p-substrate complex in which APC-free Cdh1p first binds a substrate. Engagement of the substrate Destruction Box by Cdh1p stimulates the binding of Cdh1p to the APC, presumably via a conformation change in Cdh1p. The current studies are aimed at furthering our understanding of APC-mediated proteolysis in budding yeast. In particular, we wish to identify novel APC substrates, to understand how APC-Cdh1p/Cdc20p-substrate complexes are assembled and disassembled, and to understand how the spindle assembly checkpoint makes use of a KEN box to turn off APC-mediated proteolysis when chromosomes are not properly attached to the mitotic spindle. To achieve these goals, I propose the following Specific Aims: 1) To Identify Novel APC Substrates. 2) To Assess the Generality of the APC-Cdh1p-Substrate Assembly Pathway. 3) To Determine How D-Box Engagement Stimulates Cdh1p Binding to the APC: 4) To Determine the Roles of Conserved Cdh1p Motifs and of Phosphorylation in APC-Cdh1p-Substrate Assembly. 5) To Determine Whether Disassembly of the APC-Cdh1p-Substrate Complex is an Active Process. 6) To Determine the Function of the MadSp KEN Box in the Spindle Assembly Checkpoint. Degradation of key proteins is essential for cell division. Understanding this degradation is thus important for understanding normal cell proliferation, and how this process goes awry in disease states, particularly cancers.

描述（由申请人提供）：有丝分裂进展和退出的一个关键事件是后期促进复合物（APC；也称为环体）对细胞周期蛋白和其他关键蛋白的泛素依赖性降解。 APC 底物含有降解基序，例如 Destruction Box 和 KEN Box，这些基序是其泛素化以及与 APC 激活剂 Cdc20 和 Cdh1 结合所必需的。两种基序都是有效降解所必需的，但单独其中任何一个都足以与 Cdh1p 结合。我们提出了 APC-Cdh1p-底物复合物的组装途径，其中不含 APC 的 Cdh1p 首先与底物结合。 Cdh1p 与底物破坏盒的接合刺激了 Cdh1p 与 APC 的结合，可能是通过 Cdh1p 的构象变化实现的。当前的研究旨在进一步了解芽殖酵母中 APC 介导的蛋白水解作用。特别是，我们希望鉴定新的 APC 底物，了解 APC-Cdh1p/Cdc20p-底物复合物如何组装和拆卸，并了解纺锤体组装检查点如何利用 KEN 盒来关闭 APC 介导的蛋白水解作用。没有正确附着在有丝分裂纺锤体上。为了实现这些目标，我提出以下具体目标：1) 识别新型 APC 基质。 2) 评估 APC-Cdh1p-底物组装途径的通用性。 3) 确定 D-Box 结合如何刺激 Cdh1p 与 APC 结合： 4) 确定 APC-Cdh1p-底物组装中保守的 Cdh1p 基序和磷酸化的作用。 5) 确定APC-Cdh1p-底物复合物的分解是否是主动过程。 6) 确定MadSp KEN 盒在主轴装配检查点中的功能。关键蛋白质的降解对于细胞分裂至关重要。因此，了解这种降解对于了解正常细胞增殖以及该过程在疾病状态（尤其是癌症）中如何出错非常重要。