Cleaves phosphorylated sphingoid bases (PSBs), such as sphingosine-1-phosphate, into fatty aldehydes and phosphoethanolamine. Elevates stress-induced ceramide production and apoptosis (PubMed:11018465, PubMed:14570870, PubMed:24809814, PubMed:28165339). Required for global lipid homeostasis in liver and cholesterol homeostasis in fibroblasts. Involved in the regulation of pro-inflammatory response and neutrophil trafficking. Modulates neuronal autophagy via phosphoethanolamine production which regulates accumulation of aggregate-prone proteins such as APP (By similarity). Seems to play a role in establishing neuronal contact sites and axonal maintenance (By similarity). sphinganine 1-phosphate = hexadecanal + phosphoethanolamine sphing-4-enine 1-phosphate = (2E)-hexadecenal + phosphoethanolamine Lipid metabolism; sphingolipid metabolism. Homodimer. Ubiquitously expressed (PubMed:11018465, PubMed:28165343). Expressed in fetal and adult adrenal gland (at protein level) (PubMed:28165343). The disease is caused by variants affecting the gene represented in this entry. Belongs to the group II decarboxylase family. Sphingosine-1-phosphate lyase subfamily. Extended N-terminus.