Regulation of Yeast Phosphatidate Phosphatase

酵母中的磷脂酸（PA）磷酸酶（3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4）催化PA去磷酸化生成二酰基甘油和Pi。PA磷酸酶参与酿酒酵母磷脂和甘油三酯合成的调控。两种膜相关形式（45-kDa和104-kDa）的PA磷酸酶已纯化和表征在我们的实验室。在这项拨款申请中，我们提议启动一个项目来克隆45-kDa和104-kDa形式的PA磷酸酶的结构基因。我们将使用针对这些酶的特异性抗体以及lambda-ZAP cDNA表达和lambda-DASH基因组表达文库。克隆的基因将被表征和PA磷酸酶的本质将被解决。酵母中的磷脂酸酶（PA）磷酸酶催化磷脂PA中磷酸盐的脱除，形成中性脂质二酰基甘油。这种酶在酵母和动物细胞中控制整体脂质合成中起作用。两种膜相关形式（45-kDa和104-kDa）的PA磷酸酶已经纯化和表征在我们的实验室。在这项拨款申请中，我们提议启动一个项目，分离编码45-kDa和104-kDa形式的PA磷酸酶的基因。我们将使用针对lambda病毒酶和DNA表达文库的特异性抗体。一旦分离出来，这些酶的基因将被表征。这些基因在酵母脂质合成和细胞生长中的基本性质和作用将被检查。

Phosphatidate (PA) phosphatase (3-sn-phosphatidate phosphohydrolase, EC 3.1.3.4) in the yeast Saccharomyces cerevisiae catalyzes the dephosphorylation of PA to form diacylglycerol and Pi. PA phsophatase plays a role in the regulation of phospholipid and triacylglycerol synthesis in S. cerevisiae. Two membrane- associated forms (45-kDa and 104-kDa) of PA phosphatase have been purified and characterized in our laboratory. In this grant application we propose to initiate a project to clone the structural genes for the 45-kDa and 104-kDa forms of PA phosphatase. We will use specific antibodies to the enzymes and lambda-ZAP cDNA expression and lambda-DASH genomic expression libraries. The cloned genes will be characterized and the essential nature of PA phosphatase will be addressed. %%% The enzyme phosphatidate (PA) phosphatase in the yeast Saccharomyces cerevisiae catalyzes the removal of phosphate from the phospholipid PA to form the neutral lipid diacylglycerol. This enzyme plays a role in the control of overall lipid synthesis in yeast and in animal cells. Two membrane-associated forms (45-kDa and 104-kDa) of PA phosphatase have been purified and characterized in our laboratory. In this grant application we propose to initiate a project to isolate the genes which encode for the 45-kDa and 104-kDa forms of PA phosphatase. We will use specific antibodies to the enzymes and DNA expression libraries in lambda viruses. Once isolated the genes for these enzymes will be characterized. The essential nature and role of these genes in yeast lipid synthesis and cell growth will be examined.