Molecular Mechanisms of Mammalian SIRT6 Function

哺乳动物 SIRT6 功能的分子机制

• 批准号: 7393528
• 负责人: Katrin F Chua
• 金额: $ 10.2万
• 依托单位: PALO ALTO VETERANS INSTIT FOR RESEARCH
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7393528
• 关键词: DNA binding protein; DNA damage; DNA repair; aging; alkylation; binding sites; bioassay; biochemistry; cell age; cell line; chromatin; enzyme activity; gene deletion mutation; gene induction /repression; histones; longevity; nucleosomes; oxidation; pentosyltransferase; peptide library; posttranslational modifications; protein protein interaction; protein structure function; proteomics

DESCRIPTION (provided by applicant): Sir2 (Silent Information Regulator-2) proteins function in aging and lifespan regulation in multiple model organisms. Our long-term goal is to understand the molecular mechanisms that underlie human aging and age-associated pathologies, and the role of human Sir2 factors in attenuating these processes. Preliminary work indicates that one mammalian Sir2 protein, SIRT6, suppresses genomic instability and attenuates the onset of several age-associated pathologies. However, the molecular mechanisms of SIRT6 function are not known. Thus, a systematic characterization of the basic molecular mechanisms through which SIRT6 functions in human cells should be instrumental for elucidating fundamental biological processes that impact on human health in aging. Here, the overall hypothesis to be investigated is that SIRT6 exerts its effects on aging-associated cellular processes and genome maintenance via novel functions at chromatin. A series of biochemical, cellular, and global proteomic and genomic analyses will be carried out to define the molecular functions of SIRT6 in human cells. Three Specific Aims are proposed: 1. To elucidate the molecular mechanisms by which SIRT6 functions in chromatin regulation. Post-translational modifications of histones at chromatin play important roles in gene expression programs and DNA damage responses. Preliminary results indicate that SIRT6 is tightly associated with, and may catalyze modifications of, histones at chromatin. We will define the enzymatic activity of SIRT6 at chromatin and the effects of altered SIRT6 levels on chromatin structure and functional states. 2. To elucidate the role of the human SIRT6 protein in genome stabilization and DNA repair. SIRT6-deficient cells show increased genomic instability and sensitivity to oxidative and alkylating DNA lesions that are proposed to contribute to aging. A series of functional and biochemical experiments are proposed to elucidate the molecular mechanisms by which SIRT6 exerts its effects on genome maintenance. 3. To elucidate novel SIRT6 regulated molecular pathways. Proteomic and biochemical approaches will be taken to isolate and characterize SIRT6 substrates, protein binding partners, and macromolecular complexes. In addition, genome wide approaches will be employed to identify SIRT6-regulated genes and SIRT6 binding sites at chromatin.

描述（由申请人提供）：Sir2（沉默信息调节器-2）蛋白在多种模型生物体的衰老和寿命调节中发挥作用。我们的长期目标是了解人类衰老和年龄相关病理的分子机制，以及人类 Sir2 因子在减弱这些过程中的作用。初步研究表明，一种哺乳动物 Sir2 蛋白 SIRT6 可抑制基因组不稳定性并减轻多种与年龄相关的病理的发生。然而，SIRT6功能的分子机制尚不清楚。因此，系统表征 SIRT6 在人类细胞中发挥作用的基本分子机制应该有助于阐明影响人类衰老健康的基本生物过程。在这里，要研究的总体假设是 SIRT6 通过染色质的新功能对衰老相关的细胞过程和基因组维护发挥作用。将进行一系列生化、细胞和整体蛋白质组学和基因组分析，以确定 SIRT6 在人类细胞中的分子功能。提出了三个具体目标： 1. 阐明 SIRT6 在染色质调节中发挥作用的分子机制。染色质组蛋白的翻译后修饰在基因表达程序和 DNA 损伤反应中发挥重要作用。初步结果表明，SIRT6 与染色质组蛋白紧密相关，并可能催化组蛋白的修饰。我们将定义 SIRT6 在染色质上的酶活性以及改变 SIRT6 水平对染色质结构和功能状态的影响。 2. 阐明人类SIRT6蛋白在基因组稳定和DNA修复中的作用。 SIRT6缺陷细胞表现出基因组不稳定性增加以及对氧化和烷基化DNA损伤的敏感性增加，这些损伤被认为会导致衰老。提出了一系列功能和生化实验来阐明 SIRT6 对基因组维持发挥作用的分子机制。 3. 阐明SIRT6调控的新分子途径。将采用蛋白质组学和生化方法来分离和表征 SIRT6 底物、蛋白质结合伴侣和大分子复合物。此外，将采用全基因组方法来识别 SIRT6 调节基因和染色质上的 SIRT6 结合位点。