Sphingosine-1-phosphate (SPP) is a novel lipid messenger that has dual function.
Intracellularly it regulates proliferation and survival, and extracellularly, it is a ligand for the G
protein-coupled receptor Edg-1. Based on peptide sequences obtained from purified rat
kidney sphingosine kinase, the enzyme that regulates SPP levels, we report here the
cloning, identification, and characterization of the first mammalian sphingosine kinases
(murine SPHK1a and SPHK1b). Sequence analysis indicates that these are novel kinases …