Homann M J, Poole M A, Gaynor P M, Ho C T, Carman G M
J Bacteriol. 1987 Feb;169(2):533-9. doi: 10.1128/jb.169.2.533-539.1987.
The effect of growth phase on the membrane-associated phospholipid biosynthetic enzymes CDP-diacylglycerol synthase, phosphatidylserine synthase, phosphatidylinositol synthase, and the phospholipid N-methyltransferases in wild-type Saccharomyces cerevisiae was examined. Maximum activities were found in the exponential phase of cells grown in complete synthetic medium. As cells entered the stationary phase of growth, the activities of the CDP-diacylglycerol synthase, phosphatidylserine synthase, and the phospholipid N-methyltransferases decreased 2.5- to 5-fold. The subunit levels of phosphatidylserine synthase and the cytoplasmic-associated enzyme inositol-1-phosphate synthase were not significantly affected by the growth phase. When grown in medium supplemented with inositol-choline, cells in the exponential phase of growth had reduced CDP-diacylglycerol synthase, phosphatidylserine synthase, and phospholipid N-methyltransferase activities, with repressed subunit levels of phosphatidylserine synthase and inositol-1-phosphate synthase compared with cells grown without inositol-choline. Enzyme activity levels remained reduced in the stationary phase of growth of cells supplemented with inositol-choline. The phosphatidylserine synthase and inositol-1-phosphate synthase subunit levels, however, were depressed. Phosphatidylinositol synthase (activity and subunit) was not affected by growth in medium supplemented with or without inositol-choline or the growth phase of the culture. The phospholipid composition of cells in the exponential and stationary phase of growth was also examined. The phosphatidylinositol to phosphatidylserine ratio doubled in stationary-phase cells. The phosphatidylcholine to phosphatidylethanolamine ratio was not significantly affected by the growth phase of cells.
研究了生长阶段对野生型酿酒酵母中与膜相关的磷脂生物合成酶CDP - 二酰甘油合酶、磷脂酰丝氨酸合酶、磷脂酰肌醇合酶以及磷脂N - 甲基转移酶的影响。在完全合成培养基中生长的细胞指数期发现了最大活性。当细胞进入生长稳定期时，CDP - 二酰甘油合酶、磷脂酰丝氨酸合酶和磷脂N - 甲基转移酶的活性下降了2.5至5倍。磷脂酰丝氨酸合酶和细胞质相关酶肌醇 - 1 - 磷酸合酶的亚基水平不受生长阶段的显著影响。当在添加了肌醇 - 胆碱的培养基中生长时，生长指数期的细胞中CDP - 二酰甘油合酶、磷脂酰丝氨酸合酶和磷脂N - 甲基转移酶的活性降低，与未添加肌醇 - 胆碱的细胞相比，磷脂酰丝氨酸合酶和肌醇 - 1 - 磷酸合酶的亚基水平受到抑制。在添加了肌醇 - 胆碱的细胞生长稳定期，酶活性水平仍然降低。然而，磷脂酰丝氨酸合酶和肌醇 - 1 - 磷酸合酶的亚基水平受到抑制。磷脂酰肌醇合酶（活性和亚基）不受添加或未添加肌醇 - 胆碱的培养基生长或培养物生长阶段的影响。还检测了生长指数期和稳定期细胞的磷脂组成。在稳定期细胞中，磷脂酰肌醇与磷脂酰丝氨酸的比例增加了一倍。细胞的生长阶段对磷脂酰胆碱与磷脂酰乙醇胺的比例没有显著影响。
