REGULATION OF UBIQUITINATION BY DUB-E2 UBIQUITIN CONJUGATING ENZYME COMPLEXES

DUB-E2 泛素结合酶复合物对泛素化的调节

• 批准号: 8615156
• 负责人: Cynthia Wolberger
• 金额: $ 42.16万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8615156
• 关键词: Address; BRCA1 gene; Binding; Biochemical; Biological; Biological Assay; Breast; Charge; Cleaved cell; Complex; DNA Damage; DNA Double Strand Break; DNA Repair; Data; Defect; Deubiquitinating Enzyme; Ensure; Enzymes; Equilibrium; Eukaryota; Event; Goals; Human; Immunologic Deficiency Syndromes; Inflammation; Lead; Learning; Light; Link; Malignant Neoplasms; Multienzyme Complexes; Ovarian; Pathway interactions; Pharmacotherapy; Play; Polyubiquitin; Polyubiquitination; Process; Property; Proteins; Regulation; Relative (related person); Repression; Roentgen Rays; Role; Structure; System; Testing; Time; Ubiquitin; Ubiquitin-Conjugating Enzymes; Ubiquitination; Work; base; design; drug discovery; in vivo; inhibitor/antagonist; insight; multicatalytic endopeptidase complex; mutant; prevent; public health relevance; response; thioester; ubiquitin-protein ligase

Covalent attachment of ubiquitin regulates a broad range of processes in eukaryotes. A major challenge is understanding how ubiquitination is regulated by the large network of enzymes that conjugate and remove ubiquitin from substrates, therefore controlling their fate. Many of the more than 90 human deubiquitinating enzymes (DUBs) are found in complexes containing E2 ubiquitin conjugating or E3 ubiquitin ligases enzymes, suggesting cross-regulation of opposing activities. Our long-term goal is to understand the underlying mechanism by which interactions between deubiquitinating and ubiquitin conjugating enzymes cooperate to control ubiquitination. This proposal focuses on a DUB-E2 complex that regulates key ubiquitination events in the response to DNA double strand breaks. OTUB1 is a DUB that specifically cleaves K48-linked polyubiquitin chains, yet binds to E2 enzymes and non-catalytically inhibits synthesis polyubiquitin. Preliminary results show that OTUB1-E2 interactions play an additional role in stimulating OTUB1 to cleave K48-linked polyubiquitin, and that the balance between the catalytic and non-catalytic OTUB1 activities is regulated by availability of uncharged E2 versus charged E2~Ub thioester as well as free ubiquitin. We will use a combination of biochemical, biophysical and structural approaches to investigate the mechanism underlying the dual functions of OTUB1-E2 complexes (Aim 1) and to dissect how the balance between catalytic and non-catalytic functions of OTUB1 is regulated by E2 charging, free ubiquitin and polyubiquitin chains (Aim 2). These results will provide a basis for investigating the contributions of OTUB1 cross-regulation to the temporal regulation of ubiquitination after DNA damage.

泛素的共价附着调节真核生物的广泛过程。重大挑战