Analysis of Lipolytic Trafficking in Adipocytes.

项目总结/摘要 细胞中性脂质代谢的破坏促进肥胖、糖尿病、脂肪肝的进展 疾病和癌症。该项目的长期科学目标是了解分子机制 控制脂质储存和动员，以确定治疗干预的新点。 ABHD 5调节细胞脂质代谢，包括PNPLA 2/ATGL，限速甘油三酯脂肪酶 关键的代谢组织。尽管如此，ABHD 5，一种缺乏酶活性的蛋白质， 激活PNPLA 2（和其他PNPLA）仍然是一个重要的谜团。 我们假设生物膜的重塑是ABHD 5 调节酶进入膜界定的中性脂质底物。从机制上讲，我们假设 配体结合稳定ABHD 5分子和大分子构象，靶向和改变膜 生物物理性质（张力和曲率），以允许脂肪酶进入特定的底物隔离 在脂滴（LD）内。我们将使用ABHD 5的新型化学探针和信息探针来测试这一假设。 活脂肪细胞中的遗传突变体（Aim 1）。我们将直接评估ABHD 5对生物物理学的影响， 使用高分辨率和高通量的阵列的模型LD系统中的膜的性质 方法（目标2）。这些目标旨在高度互补，并提供强有力的交叉- 实验平台之间的验证。 此外，我们目前的数据表明，ABHD 5是针对特定的亚细胞位点， 补充脂肪酸后形成LD。此外，ABHD 5与PLIN 5的相互作用，由蛋白酶驱动， ABHD 5配体油酰辅酶A促进LD形成。目标3将剖析生物化学途径促进 ABHD 5/PLIN 5复合物，并与目标2一致，评估这种相互作用对生物物理学的影响。 模型膜的性质。 ABHD 5正在成为代谢性疾病和癌症的一个引人注目的治疗靶点。结果 该项目的研究将为ABHD 5调节脂肪酸通量的具体机制提供新的见解， 胞质溶胶/LD界面。

Project Summary/Abstract Disruption of cellular neutral lipid metabolism promotes the progression of obesity, diabetes, fatty liver disease, and cancer. The long-term scientific goal of the project is to understand the molecular mechanisms that control lipid storage and mobilization in order to identify novel points for therapeutic intervention. ABHD5 regulates cellular lipid metabolism, including PNPLA2/ATGL, the rate-limiting triglyceride lipase in key metabolic tissues. Nonetheless, the mechanisms by which ABHD5, a protein lacking enzymatic activity, activates PNPLA2 (and other PNPLAs) remains an important mystery. We hypothesize that the remodeling of biological membranes is a general mechanism by which ABHD5 regulates enzyme access to membrane-delimited neutral lipid substrates. Mechanistically, we hypothesize that ligand binding stabilizes ABHD5 molecular and macromolecular conformations that target and alter membrane biophysical properties (tension and curvature) to allow the lipase access to specific substrates sequestered within lipid droplets (LDs). We will test this hypothesis using novel chemical probes of ABHD5 and informative genetic mutants in live adipocytes (Aim 1). We will directly assess the impact ABHD5 on the biophysical properties of membranes in model LD systems using an array of high resolution and high throughput approaches (Aim 2). These Aims are designed to be highly complementary and to provide strong cross- validation between experimental platforms. In addition, we present data demonstrating that ABHD5 is targeted to specific subcellular sites where LDs form upon fatty acid supplementation. Furthermore, the interaction of ABHD5 with PLIN5, driven by the ABHD5 ligand oleoyl-CoA, facilitates LD formation. Aim 3 will dissect the biochemical pathways promoted by ABHD5/PLIN5 complexes and, in concert with Aim 2, evaluate the impact of this interaction on the biophysical properties of model membranes. ABHD5 is emerging as a compelling therapeutic target for metabolic diseases and cancer. The results of this project will provide new insights into specific mechanisms by which ABHD5 regulates fatty acid flux at the cytosol/LD interface.