The Role of Acetylation in the Regulation Iron-Sulfur Cluster Biogenesis and Mito

描述（由申请人提供）：铁硫簇（ISCs）是生物学中必不可少的辅助因子，在许多细胞过程中起着各种作用。这些作用包括激活几个关键途径中涉及的关键酶，包括代谢和ATP的产生。ISCs的组装是通过核心ISC生物发生蛋白ISD11、ISCU、Nsf1和Frataxin （FXN）的高度协调活动进行的。这些核心蛋白的缺陷或缺乏导致能量代谢受损，并表现为毁灭性的人类疾病，如：由FXN水平不足引起的弗里德赖希共济失调患者的致命性心力衰竭（HF）；ISCU缺乏患者的严重肌病。因此，深入了解ISC的生物发生过程对于了解该通路在人类疾病中的作用是必要的。然而，ISC生物发生调控的分子基础仍然知之甚少。该项目的长期目标是更好地了解ISC生物发生调控，特别是ISC生物发生如何与代谢和能量需求的变化相协调。赖氨酸乙酰化及其通过线粒体NAD+依赖性蛋白去乙酰化酶Sirtuin 3 （SIRT3）的调节正在成为能量稳态的主要调节因子。SIRT3的去乙酰化酶活性调节许多参与ATP产生的代谢酶。最近的研究表明，SIRT3去乙酰化酶活性对于维持心脏组织ATP水平是必要的，这强调了SIRT3在调节线粒体能量代谢中的重要作用。蛋白质组学研究确定了几种ISC生物发生蛋白作为SIRT3调控的候选蛋白，但乙酰化在调节这一关键细胞过程中的作用尚不清楚。我们预测，ISC生物发生途径中蛋白质的乙酰化可以作为调节线粒体能量稳态的机制，正如脂肪酸代谢途径和TCA循环所证明的那样。我们确定了一个核心的ISC生物发生蛋白，这是一个强有力的候选蛋白。我们的中心假设是SIRT3的乙酰化和去乙酰化是调节酶功能的关键，从而以一种新的方式调节ISC的生物发生。我们将通过追求以下两个具体目标来验证我们的中心假设：(1)确定乙酰化对ISC生物发生中涉及的酶的生化作用；(2)确定SIRT3在体内调节ISC生物发生中的作用。我们的发现将为一个尚未探索的科学领域提供新的见解：乙酰化和ISC生物发生之间的串扰及其在能量稳态中的作用。此外，我们的研究结果可以确定一种新的策略，用于治疗能量产生受损的疾病，如HF和iscs相关疾病。

DESCRIPTION (provided by applicant): Iron-Sulfur clusters (ISCs) are essential cofactors in biology that serve a variety of roles in many cellular processes. These roles include activating key enzymes involved in several critical pathways, including metabolism and ATP production. Assembly of ISCs occurs through the highly coordinated activities of core ISC biogenesis proteins ISD11, ISCU, Nsf1, and Frataxin (FXN). Defect or deficiency of these core proteins results in impaired energy metabolism and manifests in devastating human diseases such as: the fatal heart failure (HF) in patients with Friedreich's Ataxia caused by insufficient levels of he FXN; and the severe myopathy in patients deficient in ISCU. Therefore, a deeper understanding of the process of ISC biogenesis is necessary to understand the role this pathway plays in human disease. The molecular underpinnings of ISC biogenesis regulation, however, remain poorly understood. The long-term goal of this project is to better understand ISC biogenesis regulation, particularly in how ISC biogenesis is coordinated in with changes in metabolism and energy demands. Lysine acetylation and its regulation through the mitochondrial NAD+-dependent protein deacetylase Sirtuin 3 (SIRT3) is emerging as a major regulator of energy homeostasis. SIRT3's deacetylase activity modulates many metabolic enzymes involved in ATP production. Recent studies have demonstrated that SIRT3 deacetylase activity is necessary for maintaining ATP levels in cardiac tissue-underscoring the important role of SIRT3 in regulating mitochondrial energy metabolism. Proteomic studies identified several ISC biogenesis proteins as candidates of regulation by SIRT3, but the role of acetylation in regulating this critical celluar process is unknown. We predict that acetylation of proteins in the ISC biogenesis pathway serves as a mechanism of regulating mitochondrial energy homeostasis, as has been demonstrated for fatty- acid metabolic pathways and the TCA cycle. We identified one core ISC biogenesis protein that is a strong candidate in this manner. Our central hypothesis is that acetylation and deacetylation by SIRT3 is critical in modulating enzymatic function, thereby regulating ISC biogenesis in a novel manner. We will test our central hypothesis by pursuing the following two specific aims: (1) determine the biochemical role of acetylation on the enzymes involved in ISC biogenesis, and; (2) determine the role of SIRT3 in regulating ISC biogenesis in vivo. Our findings will provide novel insights into an unexplored area of science: a crosstalk between acetylation and ISC biogenesis, and its role in energy homeostasis. Additionally, our findings could identify a new strategy for the development of therapies for diseases of impaired energy production, such as HF, and ISC-related disorders.