MINORITY PREDOCTORAL FELLOWSHIP PROGRAM

描述（由申请人提供）：酵母酿酒酵母作为研究膜磷脂合成调控的模型真核生物。磷脂合成途径中的基因和酶受到遗传（如锌耗尽）和生化（如磷酸化）机制的调节。近年来的研究表明，磷脂的合成受缺锌胁迫条件的调控。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，一种合成磷脂酰胆碱（最丰富的膜磷脂）的途径被激活，使细胞能够应对这种应激。在这个应用中，我将研究CK/7编码的胆碱激酶的调控，这种酶在肯尼迪途径中催化承诺，以响应锌的消耗。我会测量胆碱激酶活性，蛋白质和信使rna的水平。CKI1基因的转录将使用Pc/c/r/acZ报告基因进行监测。所涉及的启动子元件和转录因子的鉴定将继续进行。通过使用野生型和可用的磷酸化位点突变体，用32P在体内标记胆碱激酶，来监测胆碱激酶对锌缺乏的磷酸化状态。

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.