Sphingosine Kinase 2 (SPHK2)

SPHK2 contains the 5 highly conserved regions identified in SPHK1, although the GGKGK positively charged motif of SPHK1 is modified to GGRGL in SPHK2. In addition, SPHK2 has a region homologous to the diacylglycerol kinase catalytic site. SPHK2 shares 83% identity with mouse Sphk2. Northern blot analysis revealed a 2.8-kb transcript expressed in all 12 tissues tested, with highest expression in kidney, liver, and brain. Northern blot analysis of a mouse tissue panel revealed ubiquitous expression of a 3.1-kb transcript, with highest expression in liver and heart.SPHK2 associated with HDAC1 and HDAC2 in repressor complexes and was selectively enriched at the promoters of the genes encoding the cyclin-dependent kinase inhibitor p21 or the transcriptional regulator c-fos, where it enhanced local histone H3 acetylation and transcription.