Regulation of exosomal autotaxin activity

Autotaxin (ATX) is a lysophospholipase that catalyses the extracellular hydrolysis of lysophosphatidylcholine to generate lysophosphatidic acid (LPA). LPA acts as an agonist for a family of 6 G-protein coupled cell surface receptors regulating physiological functions such as migration, contraction, apoptosis, proliferation and HCV and HBV infection of liver cells through regulating signalling pathways including PI3kinase, phospholipase C and adenylyl cyclase. Notably ATX and LPA are important constituents of foetal calf and other cell culture sera. The ability of LPA to activate cells is tempered by cell surface lipid phosphate phosphatases (LPP) that rapidly degrade LPA.