Hydrolyzes lysophospholipids to produce the signaling molecule lysophosphatidic acid (LPA) in extracellular fluids (  ). Major substrate is lysophosphatidylcholine ( ). Can also act on sphingosylphosphorylcholine producing sphingosine-1-phosphate, a modulator of cell motility . Can hydrolyze, in vitro, bis-pNPP, to some extent pNP-TMP, and barely ATP (, ). Involved in several motility-related processes such as angiogenesis and neurite outgrowth. Acts as an angiogenic factor by stimulating migration of smooth muscle cells and microtubule formation . Stimulates migration of melanoma cells, probably via a pertussis toxin-sensitive G protein . May have a role in induction of parturition . Possible involvement in cell proliferation and adipose tissue development (Probable). Tumor cell motility-stimulating factor (, ). Required for LPA production in activated platelets, cleaves the sn-1 lysophospholipids to generate sn-1 lysophosphatidic acids containing predominantly 18:2 and 20:4 fatty acids . Shows a preference for the sn-1 to the sn-2 isomer of 1-O-alkyl-sn-glycero-3-phosphocholine (lyso-PAF) .
Subcellular locations: Secreted
Detected in blood plasma (at protein level) (, ). Predominantly expressed in brain, placenta, ovary, and small intestine. Expressed in a number of carcinomas such as hepatocellular and prostate carcinoma, neuroblastoma and non-small-cell lung cancer. Expressed in body fluids such as plasma, cerebral spinal fluid (CSF), saliva, follicular and amniotic fluids. Not detected in leukocytes. Isoform 1 is more highly expressed in peripheral tissues than in the central nervous system (CNS). Adipocytes only express isoform 1. Isoform 3 is more highly expressed in the brain than in peripheral tissues.