Lysine Malonylation and SIRT5 in Epigenetic Regulation

表观遗传调控中的赖氨酸丙二酰化和 SIRT5

• 批准号: 9198466
• 负责人: Eric M. Verdin
• 金额: $ 3.3万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-01-01 至 2017-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9198466
• 关键词: Acetyl-CoA Carboxylase; Acetylation; Active Sites; Aging; Antibodies; Bacteria; Binding; Biological; Biological Assay; Biological Process; CD4 Positive T Lymphocytes; Candidate Disease Gene; Carnitine O-Palmitoyltransferase; Cell Nucleus; Cells; Cellular Stress Response; ChIP-seq; Charge; Chromatin Structure; Cultured Cells; Cytosol; Data Set; Deacetylase; Desire for food; Diabetes Mellitus; Disease; Drops; Epigenetic Process; Family member; Fasting; Fatty Acids; Follow-Up Studies; Gene Abnormality; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genome; Genomic Segment; Genomics; Glucose; Hepatocyte; Histone Code; Histone H1; Histone H1(s); Histone H2B; Histones; Human; Hypothalamic structure; Knockout Mice; Knowledge; Light; Link; Liver; Lysine; Malonates; Malonyl Coenzyme A; Maps; Mediating; Metabolic; Metabolic Diseases; Metabolic syndrome; Metabolism; Mitochondria; Modeling; Modification; Molecular Conformation; Mus; Nicotinamide adenine dinucleotide; Nuclear; Nutritional; Nutritional status; Obesity; Pathologic; Pattern; Physiological; Proteins; Proteomics; Regulation; Reporting; Research Proposals; Role; SIRT1 gene; Sirtuins; Site; Surveys; Testing; Tissues; Transcription Initiation Site; Transcriptional Regulation; base; epigenetic regulation; fatty acid biosynthesis; fatty acid metabolism; fatty acid oxidation; fatty acid transport; feeding; histone modification; insulin secretion; knockout gene; malonyl-CoA decarboxylase; normal aging; novel; overexpression; oxidation; response; transcriptome; transcriptome sequencing

PROJECT ABSTRACT Epigenetic factors have emerged as crucial players in metabolic disorders and in aging, both of which are typically associated with a wide range of gene expression changes. The overall objective of this proposal is to investigate the roles of a novel histone modification, lysine malonylation, and its regulation by the NAD+- dependent protein deacylase SIRT5, as a novel histone modifier in epigenetic regulation of gene expression in response to metabolic changes. The model is based on our recent identification of histone H2B lysine 5 (H2BK5) as a site of malonylation regulated by SIRT5. We propose that the dynamic malonylation of histone H2B by cellular malonyl-CoA and demalonylation by SIRT5 regulates chromatin structure and gene transcription. Two specific aims are developed to test this model globally in mouse liver and then mechanistically in cultured cells. First, genomic regions bound with malonylated histones (H2BK5) and SIRT5 will be compared using ChIP-seq using tissues from wild type and Sirt5-/- mice. These studies will aim to identify the sites of SIRT5-mediated histone demalonylation. The functional consequences of histone malonylation will be evaluated by comparing gene transcriptional changes using RNA-seq between wild type and Sirt5-/- mice. This data set will be compared to the sites where SIRT5 binds to the genome and demalonylates histones to identify the direct genomic sites of SIRT5 action. Second, we will study in mechanistic details how histone malonylation is dynamically regulated by SIRT5 and by fluctuations in cellular malonyl-CoA that occur during feeding and fasting in mice. In primary cultured mouse hepatocytes, we will also test the effect of feeding malonate (which is converted into malonyl-CoA intracellularly) and the effect of manipulating the cellular synthesis or degradation of malonyl-CoA via acetyl-CoA carboxylase (synthesis) and malonyl-coA decarboxylase (degradation). This research proposal takes the first step towards understanding the function of this newly discovered histone modification, malonylation, and its eraser, SIRT5, in epigenetic regulation. It will contribute significantly to our longstanding effort of unveiling the “histone code”, its intersection with intermediary metabolism, and to advance our knowledge of gene expression regulation by epigenetic factors. Results from the proposed project will therefore permit mechanistic follow-up studies of the significance of histone malonylation and SIRT5 in epigenetic regulation and how dysregulation may contribute to both pathological conditions, such as metabolic syndrome and diabetes, and to normal aging.

项目摘要 表观遗传因素已经成为代谢紊乱和衰老的关键因素，这两种因素都是 通常与广泛的基因表达变化有关。本建议的总体目标是 研究一种新的组蛋白修饰，赖氨酸丙二酰化的作用，以及NAD+- 依赖性蛋白脱酰酶SIRT 5作为一种新的组蛋白修饰剂，在表观遗传学调控中的基因表达， 对代谢变化的反应。该模型是基于我们最近发现的组蛋白H2 B赖氨酸5 （H2 BK 5）作为由SIRT 5调节的丙二酰化位点。我们认为组蛋白的动态丙二酰化 H2 B通过细胞丙二酰辅酶A和SIRT 5的去丙二酰化调节染色质结构和基因 转录。开发了两个具体目标来在小鼠肝脏中全面测试该模型，然后 在培养的细胞中。首先，与丙二酰化组蛋白（H2 BK 5）和SIRT 5结合的基因组区域 将使用来自野生型和Sirt 5-/-小鼠的组织使用ChIP-seq进行比较。这些研究的目的是 鉴定SIRT 5介导的组蛋白去丙二酰化位点。组蛋白的功能后果 将通过使用RNA-seq比较野生型之间的基因转录变化来评估丙二酰化 和Sirt 5-/-小鼠。将该数据集与SIRT 5结合基因组的位点进行比较， 使组蛋白脱丙二酸以鉴定SIRT 5作用的直接基因组位点。第二，我们将在 机制的细节如何组蛋白丙二酰化是动态调节SIRT 5和细胞的波动， 丙二酰辅酶A，在小鼠进食和禁食期间发生。在原代培养的小鼠肝细胞中，我们还将 测试喂食丙二酸盐（其在细胞内转化为丙二酰辅酶A）的效果和 通过乙酰辅酶A羧化酶（合成）操纵丙二酰辅酶A的细胞合成或降解，以及 丙二酰辅酶A脱羧酶（降解）。 这项研究提案朝着理解这种新发现的组蛋白的功能迈出了第一步 修饰，丙二酰化，和它的橡皮擦，SIRT 5，在表观遗传调控。这将大大有助于我们 揭示“组蛋白密码”的长期努力，它与中间代谢的交叉， 通过表观遗传因素来提高我们对基因表达调控的认识。拟议项目的成果 因此，将允许对组蛋白丙二酰化和SIRT 5在 表观遗传调节以及调节异常如何导致这两种病理状况，如代谢 综合征和糖尿病，以及正常衰老。