ABHD5 Enzymatic Function and Role in Lipolysis

ABHD5 酶的功能和在脂肪分解中的作用

• 批准号: 10359860
• 负责人: Jorge Matias Caviglia
• 金额: $ 45.12万
• 依托单位: BROOKLYN COLLEGE
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-17 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10359860
• 关键词: Abbreviations; Adipose tissue; Affect; Affinity Chromatography; Animals; Bacteria; Biochemical Reaction; Biological Assay; Biomedical Research; COS Cells; Caenorhabditis elegans; Catabolism; Cells; Chimeric Proteins; Chromatography; Collaborations; Cultured Cells; Diabetes Mellitus; Diglycerides; Disease; Environment; Enzymatic Biochemistry; Enzymes; Fatty Acids; Human; Hydrolase; Hydrolysis; Incubated; Institution; Isomerase; Isomerism; Knockout Mice; Knowledge; Light; Lipase; Lipids; Lipolysis; Liver; Measures; Metabolic Diseases; Metabolic Pathway; Metals; Mus; Muscle; Mutation; Myopathy; Obesity; Obesity associated disease; Pathway interactions; Phase; Plants; Population; Principal Investigator; Production; Proteins; Publishing; Reaction; Regulation; Reporting; Research; Research Support; Role; Skin; Students; Testing; Thin Layer Chromatography; Thinness; Time; Triglycerides; base; college; experience; in vitro activity; in vivo; insight; knock-down; lipid metabolism; loss of function mutation; mutant; non-alcoholic fatty liver disease; novel; overexpression; undergraduate research experience; undergraduate student

PROJECT SUMMARY / ABSTRACT This proposal aims to determine the function of ABHD5, a protein that is essential for the catabolism of triacylglycerol in humans, as well as in other animals, worms, and plants. Loss of function mutations in, or deletion of, ABHD5 blocks the hydrolysis of triacylglycerol, which accumulates, and leads to ichthyosis, steatosis, myopathy, and other alterations. ABHD5 has been reported to activate two enzymes: ATGL, the main triacylglycerol lipase in cells, and PNPLA1, which catalyzes the synthesis of acylceramides in skin. In addition, ABHD5 has been proposed to regulate ATGL activity and thus, triacylglycerol lipolysis and storage in cells. However, the mechanism of action of ABHD5 remains undefined. Moreover, several lines of evidence suggest that ABHD5 is not a direct activator of ATGL: We have shown that overexpression of ABHD5 in mouse adipose tissue, which expresses high levels of ATGL, does not increase lipolysis. In addition, in ATGL knock-out mice, simultaneous knock-down of ABHD5 increases liver TAG further, indicating that even in the absence of ATGL, ABHD5 regulates TAG amounts, thus implying a mechanism independent of ATGL. This suggests that ABHD5 does not directly activate ATGL, but rather that ABHD5 catalyzes a different reaction in triacylglycerol lipolysis. This project proposes to conduct enzymology studies using purified ABHD5, ATGL, and catalytically dead mutant forms, to determine the enzymatic function of ABHD5, its substrates and products, and the regulation ATGL. In addition, it proposes lipidology studies to show how the proposed ABHD5 function explains the lipid alterations described in cells lacking functional ABHD5. These studies are expected to elucidate the function of ABHD5, refine the understanding of the enzymatic reactions in the lipolytic pathway, and shed light on its regulation. This new knowledge will change the current understanding of lipolysis and provide new insights into obesity and related diseases. This research will be conducted by a team composed primarily of undergraduate students. It will allow the students to gain experience in biomedical research, support research by the principal investigator, and promote collaborations that will strengthen the research environment at Brooklyn College.

项目概要/摘要 该提案旨在确定 ABHD5 的功能，ABHD5 是一种对于 三酰甘油在人类以及其他动物、蠕虫和植物中的分解代谢。损失 ABHD5 的功能突变或缺失会阻止三酰甘油的水解，从而 积累并导致鱼鳞病、脂肪变性、肌病和其他改变。 ABHD5 有 据报道可激活两种酶：ATGL，细胞中主要的三酰甘油脂肪酶，以及 PNPLA1，催化皮肤中酰基神经酰胺的合成。此外，ABHD5 已 建议调节 ATGL 活性，从而调节细胞内三酰甘油的脂肪分解和储存。 然而，ABHD5 的作用机制仍不清楚。此外，还有几行 有证据表明 ABHD5 不是 ATGL 的直接激活剂：我们已经证明 ABHD5 在表达高水平 ATGL 的小鼠脂肪组织中过度表达， 不增加脂肪分解。此外，在 ATGL 敲除小鼠中，同时敲低 ABHD5 进一步增加肝脏 TAG，表明即使没有 ATGL，ABHD5 也能调节 TAG 量，因此意味着独立于 ATGL 的机制。这表明 ABHD5 确实 不直接激活 ATGL，而是 ABHD5 催化三酰甘油中的不同反应 脂肪分解。 该项目建议使用纯化的 ABHD5、ATGL 和 催化死亡突变体形式，以确定 ABHD5 及其底物的酶功能 和产品，以及 ATGL 监管。此外，它还提出了脂质学研究来表明如何 拟议的 ABHD5 功能解释了缺乏功能的细胞中描述的脂质变化 ABHD5。 这些研究有望阐明 ABHD5 的功能，加深对 ABHD5 的理解。 脂肪分解途径中的酶促反应，并阐明其调节。这个新的 知识将改变目前对脂肪分解的理解，并提供新的见解 肥胖及相关疾病。 这项研究将由一个主要由本科生组成的团队进行。它将 让学生获得生物医学研究经验，支持校长的研究 研究者，并促进合作，以加强研究环境 布鲁克林学院。