Regulation of a novel epigenome of protein biosynthesis genes

蛋白质生物合成基因的新型表观基因组的调控

基本信息

批准号：
9055723
负责人：
STEFAN BEKIRANOV
金额：
$ 32.39万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-06-01 至 2019-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9055723
关键词：
Affect Anabolism Architecture Binding Biogenesis Biological Assay Biological Markers Bruck-de Lange syndrome Cancerous Cell Cycle Progression Cell Proliferation Cell division Cell physiology Cells ChIP-seq Chemicals Chromatin Chromatin Remodeling Factor Chromatin Structure Chromatin Structure Alteration Chromosomes Complex DNA DNA Packaging DNA biosynthesis DNA replication origin DNA-Directed RNA Polymerase Defect Ensure Exhibits Gatekeeping Gene Expression Gene Mutation Generations Genes Genetic Materials Genetic Transcription Glycolysis Goals Growth Health Histone H3 Histones Human In Vitro Kinetics Link Location Malignant Neoplasms Maps Measures Mediating Modeling Modification Mutation Normal Cell Nucleosomes Nutrient Nutritional Ontology Organism Pathway interactions Phosphorylation Phosphotransferases Play Positioning Attribute Post-Translational Protein Processing Process Proliferating Property Protamine Kinase Protein Biosynthesis Proteins Regulation Relapse Replication Initiation Replication Origin Ribosomal Proteins Ribosomal RNA Role S Phase Saccharomyces cerevisiae Signal Transduction Sirolimus Sister Chromatid Site Testing Therapeutic Therapeutic Intervention Threonine Transfer RNA Up-Regulation Yeasts cancer cell cell growth chromatin remodeling cohesin cohesion crosslink epigenome epigenomics genome-wide genome-wide analysis histone modification in vivo innovation inorganic phosphate novel novel marker promoter protein complex response theories therapeutic target transcription factor uncontrolled cell growth

项目摘要

DESCRIPTION (provided by applicant): DNA templated cellular processes require alteration of chromatin structure to dynamically facilitate access to packaged DNA. The post-translational chemical modification of histone proteins is one critical mechanism that alters chromatin structure either directly or via the recruitment of effector proteins. We have identified a novel histone kinase complex in yeast containing the conserved S-phase replication initiation kinase Cdc7, its activating protein Dbf4, and a number of additional factors. We have found that this complex phosphorylates histone H3 on threonine 45 (H3T45). The site lies at a critical location, where DNA contacts the histone octamer at the entry and exit points of the nucleosome. Therefore, modification of this site has the potential to dramatically alter DNA-histone contacts, providing access for the unwrapping of DNA. Surprisingly, genome- wide studies reveal that H3T45 phosphorylation occurs not only at the expected origins of DNA replication, but it also marks the promoters of specific genes important for cell growth. Furthermore, we find that Cdc7 physically associates with target promoters and is required for RNA polymerase recruitment and full transcription at these locations. The goals of this proposal are to test our hypothesis that the Cdc7-Dbf4 complex establishes an epigenomic state, where under favorable nutritional conditions, the modified chromatin architecture facilitates robust transcription that drives cell growth and proliferation. Furthermore, we will test a model that proposes that the modification, or subsequent nucleosome remodeling, regulates promoter activity via altering the chromatin-binding dynamics of a potential repressor complex. If our hypothesis is correct we will have identified the H3T45 residue as a gatekeeper of the nucleosome, regulating DNA accessibility at target locations for transcription. Importantly, we will have uncovered a novel regulatory network by which gene expression is coordinated to ensure the necessary cell growth that accompanies cell proliferation. Of particular importance, Cdc7 and Dbf4 are misregulated in a variety of cancers and their upregulation is indicative of lower relapse-free survival. As uncontrolled cell growth, division and DNA replication are associated with the proliferation of cancer cells we anticipate that conservation of function of this epigenomic mark will provide a biomarker of diseased states and will offer a highly unique target for cancer therapeutics.

描述（由申请人提供）： DNA 模板化细胞过程需要改变染色质结构以动态促进包装 DNA 的获取，这是直接或通过效应蛋白募集改变染色质结构的一个关键机制。酵母中含有保守的 S 期复制起始激酶 Cdc7、其激活蛋白 Dbf4 和许多其他因子的激酶复合物我们发现该复合物使组蛋白 H3 磷酸化。苏氨酸 45 (H3T45) 上的位点位于 DNA 与核小体入口和出口点处的组蛋白八聚体接触的关键位置，因此，对该位点的修饰有可能显着改变 DNA-组蛋白接触，从而提供通路。令人惊讶的是，全基因组研究表明，H3T45 磷酸化不仅发生在 DNA 复制的预期起点，而且还标志着特定基因的启动子的重要性。此外，我们发现 Cdc7 与目标启动子物理结合，并且是这些位置的 RNA 聚合酶募集和完全转录所必需的。该提案的目的是检验我们的假设，即 Cdc7-Dbf4 复合物建立表观基因组状态。在有利的营养条件下，修饰的染色质结构促进稳健的转录，从而驱动细胞生长和增殖。此外，我们将测试一个模型，该模型提出修饰或随后的核小体重塑通过调节启动子活性。如果我们的假设是正确的，我们将发现 H3T45 残基是核小体的看门人，调节转录目标位置的 DNA 可及性。通过协调基因表达以确保伴随细胞增殖所必需的细胞生长，特别重要的是，Cdc7 和 Dbf4 在多种癌症中被错误调节，并且它们的上调具有指示性。由于不受控制的高度细胞生长、分裂和 DNA 复制与癌细胞的增殖有关，我们预计这种表观基因组标记功能的保留将提供疾病状态的生物标志物，并为癌症提供独特的靶标。疗法。