The Saccharomyces cerevisiae lipin homolog is a Mg2+-dependent phosphatidate phosphatase enzyme
The Saccharomyces cerevisiae lipin homolog is a Mg2+-dependent phosphatidate phosphatase enzyme
复制标题
DOI：
10.1074/jbc.m600425200
复制
发表时间：
2006-04-07
影响因子：
4.8
通讯作者：
Carman, GM
中科院分区：
文献类型：
--
作者：
Han, GS;Wu, WI;Carman, GM
镁依赖性磷脂酸磷酸酶（3-sn-phosphatidate phosphohydrolase，EC 3.1.3.4）催化磷脂酸去磷酸化生成甘油二酯和Pi。在这项工作中，我们鉴定了酿酒酵母PAH 1（以前称为SMP 2）基因，该基因编码Mg 2+依赖性PA磷酸酶，使用来自酶的纯化制剂的氨基酸序列信息（Lin，Y. P.，和卡曼，G. M.（1989）J.Biol.Chem.264，8641-8645）。PAH 1在S.酿酒酵母的Mg 2+依赖性PA磷酸酶活性水平升高，而pah 1 δ突变导致酶活性水平降低。在大肠杆菌中的异源表达证实了Pah 1 p是一种Mg ~（2+）依赖的PA磷酸酶，并表明其酶学性质与从S.啤酒。PAH 1编码的酶活性与细胞的膜和胞质组分相关，并且酶的膜结合形式是盐可提取的。脂质分析表明，突变体缺乏PAH 1积累PA和减少量的二酰基甘油及其衍生物三酰基甘油。PAH 1编码的Mg 2+依赖性PA磷酸酶与哺乳动物脂蛋白（一种分子功能未知的脂肪调节蛋白）具有同源性。人LPIN 1在E. coli中发现，lipin 1也是一种Mg ~（2+）依赖性PA磷酸酶。
Mg2+-dependent phosphatidate (PA) phosphatase (3-sn-phosphatidate phosphohydrolase, EC3.1.3.4) catalyzes the dephosphorylation of PA to yield diacylglycerol and Pi. In this work, we identified the Saccharomyces cerevisiae PAH1 (previously known as SMP2) gene that encodes Mg2+-dependent PA phosphatase using amino acid sequence information derived from a purified preparation of the enzyme (Lin, Y.-P., and Carman, G. M. (1989) J. Biol. Chem. 264, 8641-8645). Overexpression of PAH1 in S. cerevisiae directed elevated levels of Mg2+-dependent PA phosphatase activity, whereas the pah1 Delta mutation caused reduced levels of enzyme activity. Heterologous expression of PAH1 in Escherichia coli confirmed that Pah1p is a Mg2+-dependent PA phosphatase enzyme and showed that its enzymological properties were very similar to those of the enzyme purified from S. cerevisiae. The PAH1-encoded enzyme activity was associated with both the membrane and cytosolic fractions of the cell, and the membrane-bound form of the enzyme was salt-extractable. Lipid analysis showed that mutants lacking PAH1 accumulated PA and had reduced amounts of diacyl-glycerol and its derivative triacylglycerol. The PAH1-encoded Mg2+-dependent PA phosphatase shows homology to mammalian lipin, a fat-regulating protein whose molecular function is unknown. Heterologous expression of human LPIN1 in E. coli showed that lipin 1 is also a Mg2+-dependent PA phosphatase enzyme.