Sir2 regulation and chemical modulation

拟议研究的目的是推导出机制和监管原则，控制 在酵母和人类细胞中的sirtuin酶的活性。这些原则将用于设计小型 可以激活细胞中的沉默调节蛋白的分子。Sirtuins调节许多生物学上重要的活动 包括抗逆、基因沉默和长寿。Sirtuins参与介导生物学 与卡路里限制有关的影响。热量限制已经被证明有许多积极的 对哺乳动物的健康益处包括减少脂肪生成、胰岛素敏感性和延长寿命。 这些生物学效应引起了人们对sirtuins的酶促机制的兴趣，sirtuins的酶促机制是 它们在细胞中受到调节，并且它们可能被调节的方式可以改善细胞的功能。 人体健康Sirtuins是NAD依赖性脱乙酰酶，其去除乙酰赖氨酸修饰的乙酰基。 组蛋白和转录因子，从而调节染色质和基因表达。我们和其他人已经 表明这些活性受细胞中NAD和烟酰胺水平的调节， 去乙酰化酶能够整合来自能量和代谢状态的信息以控制遗传事件。一部分 我们的目标是更好地了解这些酶的功能，以及它们如何在细胞中被调节， 建议调查以下具体目标：在目标1中，我们建议表征生物化学 这类独特的酶的功能，强调其化学新奇和NAD的掺入 在脱乙酰化反应中。在Aim 2中，我们提出要展示酶活性如何提供一种机制， 烟酰胺调节沉默调节蛋白活性。此外，最近开发的质谱法 我们希望能对烟酰胺如何调节细胞中的sirtuins获得新的见解。在目标3中，我们探索 根据去乙酰化酶反应的知识设计的去乙酰化酶的小分子活化剂的开发 机制和烟酰胺调节机制。这些活化剂体现了一种新的方法， 在细胞中上调沉默调节蛋白的作用，并为药理学干预提供潜在的切入点， 增加细胞抗应激性和细胞存活。这些目标的实现，将提供新的 深入了解这些酶的生物化学和调节，并为新的 可以激活sirtuins以治疗糖尿病和退行性疾病的治疗剂。

The objective of the proposed research is to deduce mechanistic and regulatory principles that control the activities of sirtuin enzymes in yeast and human cells. These principles will be used to design small molecules that can activate sirtuins in cells. Sirtuins regulate a host of biologically significant activities including stress resistance, gene silencing and longevity. Sirtuins are implicated in mediating biological effects associated with calorie restriction. Calorie restriction has been shown to have numerous positive health benefits in mammals including reduced adipogenesis, insulin sensitivity and increased lifespan. These biological effects have raised interest in the enzymatic mechanisms of sirtuins, the means by which they are regulated in cells and the ways in which they might be modulated pharmacologically for improved human health. Sirtuins are NAD dependent deacetylases that remove acetyl-groups of acetyllysine modified histones and transcription factors thereby regulating chromatin and gene expression. We and others have demonstrated that these actvitities are regulated by NAD and nicotinamide levels in cells, and that the sirtuins are able to integrate information from energy and metabolic states to control genetic events. As part of our goal to better understand the functions of these enzymes and how they can be modulated in cells we propose to investigate the following specific aims: In Aim1 we propose to characterize the biochemical functions of this unique class of enzymes, emphasizing their chemical novelty and the incorporation of NAD in deacetylation reactions. In Aim2 we propose to show how enzymatic activity provides a mechanism for nicotinamide regulation of sirtuin activity. In addition with a recently developed mass spectrometry method we hope to gain new insights into how nicotinamide regulates sirtuins in cells. In Aim 3 we explore the development of small molecule activators of sirtuins designed from knowledge of the sirtuin reaction mechanism and the mechanism of nicotinamide regulation. These activators embody a novel approach to upregulate sirtuin action in cells and provide a potential entrypoint for pharmacological intervention to increase cell stress resistance and cell survival. Achievement of these aims is expected to provide new insights into the biochemistry and regulation of these enzymes, and provide proof of concept for new therapeutics that can activate sirtuins to treat diabetes and degenerative disorders.