Molecular interactions of histone ubiquitylation enzymes with the nucleosome

组蛋白泛素化酶与核小体的分子相互作用

基本信息

批准号：
9119169
负责人：
SONG TAN
金额：
$ 27.96万
依托单位：
PENNSYLVANIA STATE UNIVERSITY, THE
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-01 至 2018-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9119169
关键词：
Address BRCA1 gene Binding Biochemical Biochemical Genetics Cell Maintenance Cells Chromatin Complement Complex Crystallization DNA Data Data Collection Development Embryonic Development Enzymes Eukaryotic Cell Gene Expression Gene Expression Regulation Genes Genetic Genetic Processes Genetic study Genomics Health Histone H2A Histones Homeobox Genes Individual Laboratories Malignant Neoplasms Mediating Methods Modeling Molecular Mono-S Nucleosome Core Particle Nucleosomes PRC1 Protein Physiological Play Polycomb Post-Translational Protein Processing Proteins Resolution Role Specificity Structure Substrate Specificity Testing Tumor Suppressor Proteins Ubiquitin Ubiquitin-Conjugating Enzymes X-Ray Crystallography base cancer stem cell chromatin modification chromatin protein chromatin remodeling embryonic stem cell genetic information genome-wide analysis histone modification human disease improved in vivo insight malignant breast neoplasm member new therapeutic target novel polypeptide research study small molecule success ubiquitin ligase ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): The post-translational modification of histone proteins is now established as an important mechanism for regulating gene expression in eukaryotic cells. However, a structural and mechanistic understanding of how the histone modification enzymes function on their nucleosome substrate is lacking. This shortcoming limits interpretation of the wealth of genetic, genomic and biochemical data available, and it hampers development of new therapeutics that target the many chromatin enzymes associated with human diseases including cancer. To address this deficiency, we propose to study how the PRC1 polycomb repressive complex conjugates ubiquitin to histone H2A assembled in nucleosomes. The addition of ubiquitin to histone H2A has significant biomedical consequences: mono-ubiquitylation of histone H2A by PRC1 plays a critical role in embryonic stem cell maintenance, while mono-ubiquitylation of histone H2A by BRCA1 may mediate this breast cancer protein's tumor suppressor function. This proposal focuses on the following two specific aims: 1. Determine structure of the PRC1 ubiquitylation module on the nucleosome. We propose to crystallize the E2/E3 ubiquitylation complex of UbcH5c/Ring1/Bmi1 in complex with the nucleosome core particle and to determine the atomic structure of the complex by X-ray crystallography. 2. Elucidate mechanism for PRC1 module ubiquitylation of nucleosomes. The crystallographic studies will be complemented by biochemical studies to analyze the roles of the UbcH5c E2 ubiquitin-conjugating and the Ring1b/Bmi1 E3 ubiquitin ligase proteins in ubiquitylating nucleosomal H2A.

描述（由申请人提供）：现在将组蛋白的翻译后修饰作为调节真核细胞中基因表达的重要机制。但是，缺乏对组蛋白修饰酶在其核小体底物上的作用的结构和机械理解。这种缺点限制了对可用遗传，基因组和生化数据的财富的解释，并且它阻碍了针对许多与包括癌症在内的人类疾病相关的许多染色质酶的新疗法的发展。为了解决这种缺陷，我们建议研究PRC1 PolyComb抑制性复合物如何将泛素结合到组蛋白H2A中。在组蛋白H2A中添加泛素具有显着的生物医学后果：PRC1通过PRC1对组蛋白H2a的单次化作用在胚胎干细胞维持中起着至关重要的作用，而BRCA1对组蛋白H2A的单次兴奋性可能会介导这种乳腺癌蛋白抑制这种乳腺癌的肿瘤抑制器的功能。该提案的重点是以下两个特定目的：1。确定核小体上PRC1泛素化模块的结构。我们建议将UBCH5C/RING1/BMI1的E2/E3泛素化复合物与核小体核心粒子复合在一起，并通过X射线晶体学确定复合物的原子结构。 2。阐明了核小体的PRC1模块泛素化的机制。生化研究将补充晶体学研究，以分析UBCH5C E2 E2泛素 - 偶联和RING1B/BMI1 E3泛素连接酶蛋白在泛素化核瘤H2A中的作用。