Zhou J, Saba J D
Children's Hospital Oakland Research Institute, California 94609, USA.
Biochem Biophys Res Commun. 1998 Jan 26;242(3):502-7. doi: 10.1006/bbrc.1997.7993.
Sphingosine-1-phosphate (S-1-P) has been shown to participate in the proliferative signal transduction pathways of mammalian cells. Sphingosine-1-phosphate lyase (SPL) catalyzes the breakdown of S-1-P. Using the C. elegans SPL nucleotide sequence, we identified a mouse EST as a putative candidate for the homologous gene encoding this enzyme. Sequencing of the mouse EST revealed an open reading frame of 1707 nucleotides. This putative mouse SPL gene is 62% similar and 39% identical to the C. elegans SPL gene and 59% homologous and 39.6% identical to the yeast SPL gene. Expression of the mouse SPL gene in a yeast strain-delta bst1, which carries a deletion of the SPL gene and is hypersensitive to sphingosine, restored a sphingosine-resistant phenotype, suggesting this mouse gene can functionally complement the yeast defect when expressed. In vitro enzyme assay using extracts from these sphingosine-resistant transformants confirmed the SPL activities encoded by this mouse cDNA clone. Northern analysis indicated the mouse SPL gene is expressed at various levels in different tissues. Chromosomal localization mapped this SPL gene to Chromosome 10 at 32 cM. Here, we report the identification of the first mammalian sphingosine phosphate lyase gene.
鞘氨醇-1-磷酸（S-1-P）已被证明参与哺乳动物细胞的增殖信号转导途径。鞘氨醇-1-磷酸裂解酶（SPL）催化S-1-P的分解。利用秀丽隐杆线虫的SPL核苷酸序列，我们鉴定出一个小鼠EST作为编码该酶的同源基因的推定候选物。对该小鼠EST进行测序，发现了一个1707个核苷酸的开放阅读框。这个推定的小鼠SPL基因与秀丽隐杆线虫的SPL基因相似度为62%，同一性为39%，与酵母的SPL基因同源性为59%，同一性为39.6%。在携带SPL基因缺失且对鞘氨醇高度敏感的酵母菌株delta bst1中表达小鼠SPL基因，恢复了对鞘氨醇的抗性表型，表明该小鼠基因在表达时可以在功能上弥补酵母的缺陷。使用这些抗鞘氨醇转化体的提取物进行体外酶活性测定，证实了该小鼠cDNA克隆编码的SPL活性。Northern分析表明，小鼠SPL基因在不同组织中以不同水平表达。染色体定位将该SPL基因定位于10号染色体上32 cM处。在此，我们报告首次鉴定出哺乳动物鞘氨醇磷酸裂解酶基因。
