Regulation of Membrane Phospholipid Synthesis

描述(申请人提供)：酿酒酵母是研究膜磷脂合成调控的真核生物模型。磷脂合成途径中的基因和酶受遗传机制(如锌耗竭)和生化机制(如磷酸化)的调节。最近的研究表明，磷脂的合成受锌缺乏的应激条件的调节。锌是真核细胞最佳生长和代谢所必需的元素。初步数据表明，一条合成磷脂酰胆碱的途径被激活，使细胞能够应对这种压力。磷脂酰胆碱是一种最丰富的膜磷脂。在这个应用中，我将研究CK/7编码的胆碱激酶的调节，该酶催化肯尼迪途径中的承诺，以响应锌的耗竭。我将测量胆碱激酶活性、蛋白质和信使核糖核酸的水平。CKI1基因的转录将使用Pc/c/r/acZ报告基因进行监测。将继续鉴定涉及的启动子元件(S)和转录因子(S)。利用野生型和可用的磷酸化位点突变体，通过体内32P标记蛋白来监测胆碱激酶对锌缺乏的反应的磷酸化状态。

DESCRIPTION (provided by applicant):The yeast Saccharomyces cerevisiae serves as a model eukaryote to study the regulation of membrane phospholipid synthesis. The genes and enzymes in the phospholipid synthesis pathways are regulated by genetic (e.g., zinc depletion) and biochemical (e.g., phosphorylation) mechanisms. Recent studies have shown that phospholipid synthesis is regulated by the stress condition of zinc depletion. Zinc is an essential element required for the optimal growth and metabolism of eukaryotic cells. Preliminary data indicated that a pathway for synthesizing phosphatidylcholine, the most abundant membrane phospholipid, was activated to allow cells to deal with this stress. In this application, I will examine the regulation of CK/7-encoded choline kinase, the enzyme that catalyzes the committed in the Kennedy pathway, in response to zinc depletion. I will measure the levels of choline kinase activity, protein, and mRNA. Transcription of the CKI1 gene will be monitored using a Pc/c/r/acZ reporter gene. Identification of the promoter element(s) and transcription factor(s) involved will be pursued. The phosphorylation state of choline kinase in response to zinc depletion will be monitored by in vivo labeling of the protein with 32P, using wild type and available phosphorylation site mutants.