GLYCEROL-3-PHOSPHATE ACYLTRANSFERASE

肥胖、糖尿病和动脉粥样硬化性心脏病是 与三酰甘油合成增加有关。 初始和 该途径中的关键步骤是sn-甘油-3的酰化 磷酸形成1酰基-sn-甘油-3-磷酸，其由 甘油-3-磷酸酰基转移酶GPAT由于这一步被认为是 作为利率限制，GPAT可能在以下方面发挥关键作用： 调节甘油三酯和磷脂的生物合成。 具体 本研究提案的目的是了解活动， 调节，并要求线粒体GPAT在其背景下， 控制甘油脂质的生物合成。 为了研究GPAT活动，我将 使用寡核苷酸定向诱变来鉴定关键氨基酸 GPAT作用所需的酸。 蛋白酶可及性研究将 确定线粒体外膜中GPAT的形貌， 从而有助于理解活动和调节。 GPAT 监管将直接通过确定它是否 磷酸化和失活的营养状态与 减少三酰甘油合成。 GPAT与 其它的甘油酯生物合成酶将通过使用 酵母双杂交系统的构建和交联实验。最后， 线粒体GPAT在指导脂肪酸命运中的作用 在不同的营养和激素状态下， 组织培养系统过表达或缺乏线粒体GPAT。

Obesity, diabetes mellitus, and atherosclerotic heart disease are associated with increases in triacylglycerol synthesis. The initial and committed step in this pathway is the acylation of sn-glycerol-3 phosphate to form 1 acyl-sn-glycerol-3-phosphate which is catalyzed by glycerol-3-phosphate acyltransferase GPAT. Since this step is believed to be rate limiting, GPAT is likely to play the pivotal role in regulating triacylglycerol and phospholipid biosynthesis. The specific purpose of this research proposal is to understand the activity, regulation, and requirement for mitochondrial GPAT in the context of its control of glycerolipid biosynthesis. To study GPAT activity, I will use oligonucleotide directed mutagenesis to identify the critical amino acids required for GPAT action. Protease accessibility studies will determine the topography of GPAT in the outer mitochondrial membrane and thereby aid in understanding both activity and regulation. GPAT regulation will be examined directly by determining if it is phosphorylated and inactivated during nutritional states associated with decreased triacylglycerol synthesis. Interactions between GPAT and other enzymes of glycerolipid biosynthesis will be examined through use of the yeast two-hybrid system and cross-linking experiments. Finally, the role of mitochondrial GPAT in directing the fate of fatty acids during different nutritional and hormonal states will be examined in tissue culture systems overexpressing or lacking mitochondrial GPAT.