Molecular cloning and characterization of a lipid phosphohydrolase that degrades sphingosine-1-phosphate and induces cell death

作     者：Mandala, SM Thornton, R Galve-Roperh, I Poulton, S Peterson, C Olivera, A Bergstrom, J Kurtz, MB Spiegel, S 

作者机构：Georgetown Univ Med Ctr Dept Biochem & Mol Biol Washington DC 20007 USA Merck Res Labs Dept Infect Dis Rahway NJ 07065 USA 

出 版 物：《PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA》 (美国国家科学院汇刊)

年 卷 期：2000年第97卷第14期

页      面：7859-7864页

核心收录：

学科分类：07[理学] 08[工学] 

基　　金：NIGMS NIH HHS [GM43880  R01 GM043880  R37 GM043880] Funding Source: Medline 

主　　题：氨基酸序列 细胞凋亡 克隆 分子 DNA 互补/遗传学 基因表达 溶血磷脂素类 膜蛋白质类 分子序列数据 磷酸单酯水解酶类/遗传学 磷酸单酯水解酶类/代谢 RNA 信使/分离和提纯 酿酒酵母蛋白质类 序列同源性 氨基酸 鞘氨醇/类似物和衍生物 鞘氨醇/代谢 底物特异性 组织分布 动物 小鼠 

摘      要：Sphingosine and sphingosine-1-phosphate (SPP) are interconvertible sphingolipid metabolites with opposing effects on cell growth and apoptosis. Based on sequence homology with LBP1, a lipid phosphohydrolase that regulates the levels of phosphorylated sphingoid bases in yeast, we report here the cloning, identification, and characterization of a mammalian SPP phosphatase (mSPP1). This hydrophobic enzyme, which contains the type 2 lipid phosphohydrolase conserved sequence motif, shows substrate specificity for SPP. Partially purified Myc-tagged mSPP1 was also highly active at dephosphorylating SPP. When expressed in yeast, mSPP1 can partially substitute for the function of LBP1. Membrane fractions from human embryonic kidney HEK293 cells transfected with mSPP1 markedly degraded SPP but not lysophosphatidic acid, phosphatidic acid, or ceramide-1-phosphate. Enforced expression of mSPP1 in NIH 3T3 fibroblasts not only decreased SPP and enhanced ceramide levels, it also markedly diminished survival and induced the characteristic traits of apoptosis. Collectively, our results suggest that SPP phosphohydrolase may regulate the dynamic balance between sphingolipid metabolite levels in mammalian cells and consequently influence cell fate.