REGULATION OF PHOSPHOLIPID SYNTHESIS

在酿酒酵母中，CTP是所有膜的前体 磷脂酰乙醇胺甲基化合成磷脂 （主要）和CDP-乙醇胺-和CDP-胆碱基（辅助） 途径。这项拨款申请解决了细胞 CTP的水平调节磷脂的合成， 辅助途径的表达和/或活性， 这些途径中的酶。CTP对磷脂合成的影响 将使用S.酿酒酵母菌株表达各种 CTP水平。CTP水平将通过以下基因的表达而变化： URA7基因，其编码CTP合成酶。mRNA丰度和蛋白质 磷脂生物合成酶的水平将被检查， 不同级别的CTP。酶活性的生化调节 我们亦会研究市民对现金转拨计划的反应。由于细胞CTP水平必须 受CTP合成酶的表达和/或活性控制。这 本申请还将解决CTP合成酶活性是否受 已知调节磷脂合成的因子。CTP合成酶将是 通过分子遗传学和/或生物化学方法纯化， 制备用于调节的抗CTP合成酶抗体的用途 问题研究纯化的酶将在其生物学特性方面进行表征。 基本酶学和动力学性质。CTP的调节 合成酶通过cAMP依赖性蛋白激酶磷酸化将是 在体内和体外检测。将从以下来源获得的信息： 这些研究应该对其他人的工作有很大的帮助和补充。 磷脂代谢领域的研究人员以及那些 研究核苷酸代谢

In the yeast Saccharomyces cerevisiae, CTP is a precursor of all membrane phospholipids synthesized by the phosphatidylethanolamine methylation (primary) and CDP-ethanolamine- and CDP-choline-based (auxiliary) pathways. This grant application addresses the hypothesis that cellular levels of CTP regulate the synthesis of phospholipids by the primary and auxiliary pathways by controlling the expression and/or activities of the enzymes in these pathways. The effects of CTP on phospholipid synthesis will be examined in vivo using S. cerevisiae strains expressing various levels of CTP. CTP levels will be varied through the expression of the URA7 gene, which encodes CTP synthetase. The mRNA abundance and protein levels of phospholipid biosynthetic enzymes will be examined in response to various levels of CTP. Biochemical regulation of enzyme activities in response to CTP will also be examined. Since cellular CTP levels must be governed by the expression and/or activity of CTP synthetase. This application will also address if CTP synthetase activity is regulated by factors known to regulated phospholipid synthesis. CTP synthetase will be purified by molecular genetic and/or biochemical approaches for the purpose of preparing anti-CTP synthetase antibodies for regulation studies. The purified enzyme will be characterized with respect to its basic enzymological and kinetic properties. The regulation of CTP synthetase by cAMP-dependent protein kinase phosphorylation will be examined in vivo and in vitro. The information that will be obtained from these studies should be of great use to, and complement the work of other investigators in the field of phospholipid metabolism as well as those working on nucleotide metabolism.