Pseudosubstrate Inhibition of the Anaphase Promoting Complex

后期促进复合物的假底物抑制

• 批准号: 7933644
• 负责人: MARK J SOLOMON
• 金额: $ 33.09万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-24 至 2011-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7933644
• 关键词: Address; Anaphase; Binding; Boxing; Cell Cycle; Cell Cycle Completion; Cell Cycle Progression; Cell Cycle Proteins; Cell Differentiation process; Chromosomes; Complex; Cyclin-Dependent Kinases; Cyclins; Genetic Screening; Growth; Human; Lysine; Microtubules; Mitosis; Motor; Nature; Pathway interactions; Phosphorylation; Proteins; Proteolysis; Regulation; Relative (related person); Role; Saccharomycetales; Signal Pathway; Stimulus; Testing; Time; Tissues; Ubiquitin-mediated Proteolysis Pathway; Ubiquitination; Yeasts; anaphase-promoting complex; genetic selection; human PTTG1 protein; inhibitor/antagonist; interest; novel; research study; response; ubiquitin ligase

Proper functioning of the cell cycle and its regulation in response to both internal and external stimuli is essential for the normal growth, division, and differentiation of cells and tissues. Major control over cell cycle progression is exerted by ubiquitin- mediated proteolysis. For instance, the initiation of chromosome separation (anaphase) and completion of the cell cycle require the degradation of a number of cell cycle regulatory proteins such as cyclins, securin (which regulates the protein holding chromosomes together), and microtubule motor proteins. The ubiquitin ligase (or E3) for this proteolysis is termed the Anaphase Promoting Complex (APC). Proteins are targeted to the APC by two substrate recognition proteins, Cdc20 and Cdh1, active during late mitosis and in G1, respectively. An emerging theme in the regulation of the APC involves the actions of pseudosubstrates, proteins that are not themselves APC substrates but that compete with substrates for binding to Cdc20 and Cdh1 via the Destruction Box and KEN Box sequences found in APC substrates. Acm1 is a recently- identified pseudosubstrate inhibitor of APCCdh1 in budding yeast. In addition to a Destruction Box and a KEN box, Acm1 contains a novel motif that facilitates its interaction with Cdh1. Acm1 is also subject to ubiquitin-mediated proteolysis, both by APCCdc20 during mitosis and by an unidentified mechanism throughout the cell cycle, and is protected from both pathways via phosphorylation. To further our understanding of APC regulation via pseudosubstrate inhibition, we propose the following Specific Aims: 1) To determine the Acm1 motifs and cellular pathways responsible for Acm1 degradation and the role(s) of Acm1 phosphorylation in protecting it from degradation. 2) To use genetic screens to identify novel human and yeast pseudosubstrate APC inhibitors. We will also further explore the mechanism by which the vertebrate Emi1 protein acts as a pseudosubstrate inhibitor.

细胞周期的正确功能及其对两个内部的调节 外部刺激对于正常生长，分裂和分化至关重要 细胞和组织。泛素 - 对细胞周期进程的主要控制 - 介导的蛋白水解。例如，染色体分离的启动（后期） 细胞周期的完成需要降解许多细胞周期 调节蛋白，例如细胞周期蛋白Securin（调节蛋白质保持 染色体）和微管运动蛋白。泛素连接酶（或E3） 因为这种蛋白水解被称为后期促进复合物（APC）。蛋白质是 由两个底物识别蛋白CDC20和CDH1靶向APC 在晚期有丝分裂和G1期间。监管中的一个新兴主题 APC涉及伪造物的作用，蛋白质本身不是APC 底物，但与底物竞争，通过结合Cdc20和cdh1 APC基板中发现的破坏框和KEN框序列。 ACM1是最近的 鉴定出在萌芽酵母中APCCDH1的假基底抑制剂。除了 破坏盒和一个ken盒子，ACM1包含一个新型图案，可促进其 与CDH1的相互作用。 ACM1也受到泛素介导的蛋白水解的约束，均由 在有丝分裂期间的APCCDC20和整个细胞周期中未识别的机制，以及 通过磷酸化保护两种途径。 为了进一步了解APC调节通过伪造的抑制作用， 我们提出以下具体目标： 1）确定负责ACM1的ACM1基序和细胞途径 降解和ACM1磷酸化在保护其免受降解中的作用。 2）使用遗传筛选来识别新型的人和酵母菌假子APC 抑制剂。 我们还将进一步探讨脊椎动物EMI1蛋白的机制 伪基底抑制剂。