Novel SIRT5 Enzymatic Activity Regulates Cellular Mechanisms of Aging and Disease

描述（由申请人提供）：目前对衰老的研究主要集中在年龄相关疾病的分子机制上，线粒体功能障碍与几种人类衰老疾病有关。然而，线粒体功能障碍的细胞机制以及它们如何导致与年龄相关的疾病尚不清楚。线粒体蛋白的化学修饰控制线粒体功能的几个方面，本项目的长期目标是了解这些修饰如何受到NAD（+）依赖性沉默调节蛋白脱酰基酶的调节，并影响衰老疾病。该提案的目的是定义SIRT 5在衰老分子机制中的作用。核心假设是SIRT 5通过从线粒体蛋白中去除新发现的酰基修饰来调节线粒体功能。在缺乏SIRT 5的情况下，线粒体蛋白将变得过度酰化，线粒体功能降低，并表现出加速老化的几个标志物。这一假设的基本原理是基于初步数据，这表明SIRT 5在衰老和疾病的细胞机制中起着重要作用。为了验证这些假设，我们将追求三个具体目标：1。确定蛋白质酰化的变化作为年龄的函数，使用蛋白质组学策略来量化来自年轻、中年和老年小鼠的肝线粒体蛋白质酰化; 2.通过使用细胞和鼠模型的组合来确定这种新的酰基修饰对蛋白质功能的影响，以测量特定蛋白质的蛋白质活性的变化，以及蛋白质的总体功能。 线粒体; 3.通过在小鼠中使用体外细胞测定和体内测定测量衰老的几个生理参数来确定SIRT 5对衰老的作用，以确定SIRT 5如何在衰老期间维持线粒体和细胞稳态。这项研究结合了一种新的蛋白质修饰，一个全面的实验设计和一个创新的概念框架。此外，这项研究将为这一早期研究者奠定基础，并确保成功的研究计划专注于衰老和疾病的细胞机制。重要的是，这项研究意义重大，因为它有望推进和扩大对线粒体功能障碍如何导致年龄相关疾病的理解。最终，这些知识有可能为开发针对几种衰老疾病的新疗法提供信息。

DESCRIPTION (provided by applicant): Current research on aging has largely focused the molecular mechanisms of age-related diseases, and mitochondrial dysfunction has been associated with several human diseases of aging. However, the cellular mechanisms of mitochondrial dysfunction and how they lead to age-related diseases are not known. Chemical modifications to mitochondrial proteins control several aspects of mitochondrial function, and the long-term goal of this project is to understand how these modifications are regulated by the NAD(+)-dependent sirtuin deacylases and influence the diseases of aging. The objective of this proposal is to define the role of SIRT5 in the molecular mechanisms of aging. The central hypothesis is that SIRT5 regulates mitochondrial function by removing a newly discovered acyl modification from mitochondrial proteins. In the absence of SIRT5, mitochondrial proteins will become hyper-acylated, have reduced mitochondrial function, and exhibit several markers of accelerated aging. The rationale for this hypothesis is based on preliminary data, which suggests an important role for SIRT5 in the cellular mechanisms of aging and disease. To test these hypotheses, three specific aims will be pursued: 1. Determine the changes in protein acylation as a function of age, using a proteomic strategy to quantify hepatic mitochondrial protein acylation from young, middle-aged, and old mice; 2. Determine the effect of this novel acyl modification on protein function by using a combination of cell and murine models, in order to measure the changes in protein activity of specific proteins, as well as the overall function of mitochondria; 3. Determine role of SIRT5 on aging by measuring several physiological parameters of aging using both in vitro cellular assays and in vivo assays in mice, to determine how SIRT5 maintains mitochondrial and cellular homeostasis during aging. This study combines a novel protein modification, a comprehensive experimental design, and an innovative conceptual framework. Furthermore, this study will build a foundation for this early-stage investigator and ensure a successful research program focused on the cellular mechanisms of aging and disease. Importantly, the proposed research is significant because it is expected to advance and expand understanding how mitochondrial dysfunction can lead to age-related diseases. Ultimately such knowledge has the potential to inform the development of new therapies against several diseases of aging.