Shen H, Heacock P N, Clancey C J, Dowhan W
Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston 77225, USA.
J Biol Chem. 1996 Jan 12;271(2):789-95. doi: 10.1074/jbc.271.2.789.
An open reading frame (CDS1) residing on chromosome II of Saccharomyces cerevisiae encodes a hydrophobic protein with a predicted molecular mass of 51,789 Da, which exhibits 29 and 37% amino acid sequence identities with CDP-diacylglycerol synthases reported from Escherichia coli and Drosophila, respectively. Induction of expression of a GAL1 promoter-driven CDS1 gene on a multicopy plasmid in a cds1 null mutant background resulted in synthase activity 10 times that of wild-type cells and an elevation in the apparent initial rate of synthesis of phosphatidylinositol relative to phosphatidylserine. Without induction, activity was reduced to 10% of wild-type levels, which was sufficient to support growth but resulted in an inositol excretion phenotype, and had an opposite effect on the above phospholipid synthesis. Null cds1 mutants were incapable of spore germination or vegetative growth and could not be complemented under uninduced conditions with a GAL1 promoter-driven CDS1 gene on a low copy plasmid. Therefore, the essential CDS1 gene encodes the majority, if not all, of the synthase activity. The lack of consensus RNA splice sites derived from the genomic CDS1 sequence predicts that the multiple subcellular locations for synthase activities do not arise through RNA processing events.
位于酿酒酵母二号染色体上的一个开放阅读框（CDS1）编码一种疏水蛋白，预测分子量为51,789道尔顿，该蛋白与分别来自大肠杆菌和果蝇的CDP - 二酰基甘油合酶的氨基酸序列一致性分别为29%和37%。在cds1缺失突变体背景下，多拷贝质粒上由GAL1启动子驱动的CDS1基因表达的诱导导致合酶活性是野生型细胞的10倍，且相对于磷脂酰丝氨酸，磷脂酰肌醇的表观初始合成速率升高。在未诱导的情况下，活性降至野生型水平的10%，这足以支持生长，但导致肌醇排泄表型，并且对上述磷脂合成有相反的影响。cds1缺失突变体无法进行孢子萌发或营养生长，并且在未诱导条件下不能用低拷贝质粒上由GAL1启动子驱动的CDS1基因进行互补。因此，必需的CDS1基因编码了大部分（如果不是全部）合酶活性。从基因组CDS1序列中缺乏共有RNA剪接位点预测，合酶活性的多个亚细胞定位不是通过RNA加工事件产生的。
