Spinster Homolog 2 (SPNS2)

SPNS2 contains 548 amino acids and shares significant homology with zebrafish Spns2. Kawahara et al. (2009) showed that zebrafish Spns2, which contains 12 transmembrane domains, was expressed at the membrane of transfected Chinese hamster ovary cells. Overexpression of either zebrafish or human SPNS2 increased the release of sphingosine-1-phosphate (S1P) into the culture medium. Kawahara et al. (2009) concluded that SPNS2 functions as an S1P transporter in S1P secretion.an N-ethyl-N-nitrosurea-induced arg153-to-ser mutation in zebrafish Spns2 led to cardiac bifida. Expression of human SPNS2, but not human SPNS1 , reversed the defect. The defect was also rescued by S1P injection or by reintroduction of zebrafish Spns2 in extraembryonic tissue yolk syncytial layer.