Regulation of Yeast Phosphatidate Phosphatase

酿酒酵母中的磷脂酸(PA)磷酸酶(3-sn-磷脂酸盐磷酸水解酶，EC 3.1.3.4)催化PA脱磷生成二酰甘油和PI。PA磷酸酶在调节酿酒酵母磷脂和三酰甘油的合成中起着重要作用。本实验室已纯化并鉴定了两种膜结合形式的PA磷酸酶(45-kDa和104-kDa)。在这项拨款申请中，我们建议启动一个项目，克隆45 kDa和104 kDa形式的PA磷酸酶的结构基因。我们将使用针对酶的特异性抗体和lambda-ZAP基因表达文库和lambda-dash基因组表达文库。将对克隆的基因进行表征，并对PA磷酸酶的基本性质进行阐述。酿酒酵母中的磷脂酸(PA)磷酸酶催化磷脂PA脱除磷酸盐，生成中性脂二酰甘油。这种酶在酵母和动物细胞中的总脂肪合成中起着控制作用。本实验室已纯化并鉴定了两种膜结合形式的PA磷酸酶(45-kDa和104-kDa)。在这项拨款申请中，我们建议启动一个项目，分离编码45-kDa和104-kDa PA磷酸酶的基因。我们将使用针对Lambda病毒中酶和DNA表达文库的特异性抗体。一旦分离出来，这些酶的基因将被鉴定。这些基因在酵母脂肪合成和细胞生长中的基本性质和作用将被检验。

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.