Importance of Peroxisomal Coenzyme A Degradation in Glucose Metabolism

项目总结/摘要 辅酶A（CoA）是一种重要的辅因子，参与了数百种代谢过程。因为它是 辅酶A是一种重要的辅因子，它的水平受到严格的调控。在糖尿病小鼠中， 肝脏中CoA的过量产生驱动过量的葡萄糖产生，并导致这些动物的高血糖症。 这种表型与组成性低辅酶A降解有关，这一过程正在成为一种新的代谢途径。 潜在的重要机制CoA调节。Nudt 7和Nudt 19是两种哺乳动物过氧化物酶体 具有CoA降解活性的酶，分别在肝脏和肾脏中高度表达。有限 关于Nudt 7和Nudt 19的生物化学信息是可用的;它们不同特征的结构基础 以及Nudt 7和Nudt 19对维持体内稳态CoA水平的贡献程度， 目前未知。拟议中的研究将使用包括诱变， 分子建模、纯化蛋白质的酶促分析和全组织中的靶向代谢物分析 匀浆和亚细胞级分，以：1）表征生物化学，结构和调节 Nudt 7和Nudt 19的性质和2）确定Nudt 7的遗传操作对 小鼠肝脏中的亚细胞CoA水平和葡萄糖代谢。这项研究将确立 CoA调节中的降解以及靶向该过程以控制和纠正 肝脏和肾脏的代谢失调。

PROJECT SUMMARY/ABSTRACT Coenzyme A (CoA) is an essential cofactor required for hundreds of metabolic processes. Because it is such a critical cofactor, CoA levels are tightly regulated. In diabetic mice, an abnormally high concentration of CoA in the liver drives excess glucose production and contributes to the hyperglycemia of these animals. This phenotype is associated with constitutively low CoA degradation, a process that is emerging as a potentially important mechanism for CoA regulation. Nudt7 and Nudt19 are two mammalian peroxisomal enzymes with CoA-degrading activity, which are highly expressed in the liver and kidney, respectively. Limited information is available on the biochemistry of Nudt7 and Nudt19; the structural basis for their distinct features and the extent to which Nudt7 and Nudt19 contribute to maintaining homeostatic CoA levels in vivo are currently unknown. The proposed research will use a combination of techniques including mutagenesis, molecular modeling, enzymatic assays on purified proteins, and targeted metabolite analysis in whole tissue homogenates and subcellular fractions to: 1) characterize the biochemical, structural, and regulatory properties of Nudt7 and Nudt19 and 2) determine the effects that genetic manipulations of Nudt7 have on subcellular CoA levels in mouse liver and on glucose metabolism. This research will establish the importance of degradation in the regulation of CoA and the potential of targeting this process to control and correct dysregulated metabolism in the liver and kidneys.