Role of Sirt4 in aging

描述（由申请人提供）： 沉默信息调节因子（Sir）蛋白，Sir2，是一种NAD+依赖性组蛋白脱乙酰酶，介导染色质沉默，并为沉默，代谢和酵母衰老之间的遗传联系提供证据。哺乳动物Sir2同源物Sirt4的作用尚不清楚。我将分析Sirt4的生物化学和生物学。氨基酸序列比较表明，Sift4结合NAD+，但可能识别独特的底物。我将开发Sift4的蛋白质纯化系统，并测量脱乙酰酶和ADP核糖基转移酶活性。为了确定体内结合伴侣和细胞靶点，我将结合联合收割机免疫沉淀，凝胶过滤和酵母双杂交技术。Sirt4在哺乳动物中调节细胞死亡或衰老吗？我将通过细胞培养siRNA实验和Sirt4基因敲除小鼠的建立来研究Sift4的体内功能。我的发现将为Sir2同系物在高等生物中的功能提供重要信息。

DESCRIPTION (provided by applicant): Silent information regulator (Sir) protein, Sir2, is an NAD+-dependent histone deacetylase that mediates chromatin silencing and provides evidence for a genetic link between silencing, metabolism, and aging in yeast. The role of the mammalian Sir2 homolog, Sirt4, is not known. I will analyze the biochemistry and biology of Sirt4. Amino acid sequence comparisons suggest that Sift4 binds NAD+, but may recognize unique substrates. I will develop a protein purification system for Sift4 and measure deacetylase and ADP ribosyltransferase activity. To identify in vivo binding partners and cellular targets, I will combine immunoprecipitation, gel filtration, and yeast 2-hybrid techniques. Does Sirt4 function to regulate cell death or aging in mammals? I will study in vivo function of Sift4 by cell culture siRNA experiments and the creation of Sirt4 null mice. My findings will provide vital information on how Sir2 homologs function in higher organisms.