SGPL1: Proteins and Enzymes

SGPL1 (Sphingosine-1-phosphate lyase; also hSPL) is a 60-63 kDa member of the SGPL1 subfamily, group II decarboxylase family of enzymes. It is very widely expressed, and particularly concentrated in cells undergoing rapid turnover. SGPL1 is found in the ER, and cleaves phosphorylated sphingoid bases into fatty aldehydes and phosphoethanolamine. This regulates a diversity of cellular processes such as apoptosis and T cell migration. Human SGPL1 is 568 amino acids (aa) in length. It is a type III transmembrane protein (luminal N-terminus with no signal sequence) that contains a 507 aa cytoplasmic domain (aa 62-568). This domain contains a vitamin B6 binding site (aa 344-364) that is part of a large catalytic region (aa 116-506). Over aa 342-568, human SGPL1 shares 86% aa identity with mouse SGPL1.