Major types of SPHK inhibitor
It is found that SPHK expressed two cell subtypes in human body, SphK1 and SphK2 respectively. Their distribution in time and space are different, and SphK1 is transcribed before SphK2. SphK1 is mainly expressed in the lungs, spleen and liver, while SphK2 is highly expressed in the liver and heart. The amino acid sequences and compositions of the two are highly similar, and there are 5 conserved sequences, all of which have a proline-rich SH3 joint region, which is the basis for their biological functions. Both SphK1 and SphK2 are regulated by extracellular stimulation.