MEPVECPRGLLPRPCRVLVLLNPQGGKGKALQLFQSRVQPFLEEAEITFKLILTERKNHARELVCAEELGHWDALAVMSGDGLMHEVVNGLMERPDWETAIQKPLCSLPGGSGNALAASVNHYAGYEQVTNEDLLINCTLLLCRRRLSPMNLLSLHTASGLRLYSVLSLSWGFVADVDLESEKYRRLGEIRFTVGTFFRLASLRIYQGQLAYLPVGTVASKRPASTLVQKGPVDTHLVPLEEPVPSHWTVVPEQDFVLVLVLLHTHLSSELFAAPMGRCEAGVMHLFYVRAGVSRAALLRLFLAMQKGKHMELDCPYLVHVPVVAFRLEPRSQRGVFSVDGELMVCEAVQGQVHPNYLWMVCGSRDAPSGRDSRRGPPPEEP

Catalyzes the phosphorylation of sphingosine to form sphingosine 1-phosphate (SPP), a lipid mediator with both intra- and extracellular functions (PubMed:17346996, PubMed:21084291, PubMed:25417698, PubMed:29662056, PubMed:33334894). Also acts on D-erythro-sphingosine and to a lesser extent sphinganine, but not other lipids, such as D,L-threo-dihydrosphingosine, N,N-dimethylsphingosine, diacylglycerol, ceramide, or phosphatidylinositol (PubMed:9726979). In contrast to proapoptotic SPHK2, has a negative effect on intracellular ceramide levels, enhances cell growth and inhibits apoptosis (PubMed:16118219). Involved in the regulation of inflammatory response and neuroinflammation. Via the product sphingosine 1-phosphate, stimulates TRAF2 E3 ubiquitin ligase activity, and promotes activation of NF-kappa-B in response to TNF signaling (By similarity). In response to TNF and in parallel to NF-kappa-B activation, negatively regulates RANTES induction through p38 MAPK signaling pathway (By similarity). Involved in endocytic membrane trafficking induced by sphingosine, recruited to dilate endosomes, also plays a role on later stages of endosomal maturation and membrane fusion independently of its kinase activity (PubMed:27806293, PubMed:28049734). In Purkinje cells, seems to be also involved in the regulation of autophagosome-lysosome fusion upon VEGFA (PubMed:25417698).