ENPP2
Description
The ENPP2 (ectonucleotide pyrophosphatase/phosphodiesterase 2) is a protein-coding gene located on chromosome 8.
Autotaxin, also known as ectonucleotide pyrophosphatase/phosphodiesterase family member 2 (E-NPP 2), is an enzyme that in humans is encoded by the ENPP2 gene.
== Function == Autotaxin is a secreted enzyme important for generating the lipid signaling molecule lysophosphatidic acid (LPA). Autotaxin has lysophospholipase D activity that converts lysophosphatidylcholine into LPA. Autotaxin was originally identified as a tumor cell-motility-stimulating factor; later it was shown to be LPA (which signals through lysophospholipid receptors), the lipid product of the reaction catalyzed by autotaxin, which is responsible for its effects on cell-proliferation. The protein encoded by this gene functions as a phosphodiesterase. Autotaxin is secreted and further processed to make the biologically active form. Several alternatively spliced transcript variants have been identified. Autotaxin is able to cleave the phosphodiester bond between the α and the β position of triphosphate nucleotides, acting as an ectonucleotide phosphodiesterase producing pyrophosphate, as most members of the ENPP family. Importantly, autotaxin also acts as phospholipase, catalyzing the removal of the head group of various lysolipids. The physiological function of autotaxin is the production of the signalling lipid lysophosphatidic acid (LPA) in extracellular fluids. LPA evokes growth factor-like responses including stimulation of cell proliferation and chemotaxis.
Hydrolyzes lysophospholipids to produce the signaling molecule lysophosphatidic acid (LPA) in extracellular fluids (PubMed:15769751, PubMed:26371182, PubMed:27754931, PubMed:14500380, PubMed:12354767). Major substrate is lysophosphatidylcholine (PubMed:12176993, PubMed:27754931, PubMed:14500380). Can also act on sphingosylphosphorylcholine producing sphingosine-1-phosphate, a modulator of cell motility (PubMed:14500380). Can hydrolyze, in vitro, bis-pNPP, to some extent pNP-TMP, and barely ATP (PubMed:15769751, PubMed:12176993). 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 (PubMed:11559573). Stimulates migration of melanoma cells, probably via a pertussis toxin-sensitive G protein (PubMed:1733949). May have a role in induction of parturition (PubMed:12176993). Possible involvement in cell proliferation and adipose tissue development (Probable). Tumor cell motility-stimulating factor (PubMed:1733949, PubMed:11559573). 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 (PubMed:21393252). Shows a preference for the sn-1 to the sn-2 isomer of 1-O-alkyl-sn-glycero-3- phosphocholine (lyso-PAF) (PubMed:21393252). {ECO:0000269|PubMed:11559573, ECO:0000269|PubMed:12176993, ECO:0000269|PubMed:12354767, ECO:0000269|PubMed:14500380, ECO:0000269|PubMed:15769751, ECO:0000269|PubMed:1733949, ECO:0000269|PubMed:21240271, ECO:0000269|PubMed:21393252, ECO:0000269|PubMed:26371182, ECO:0000269|PubMed:27754931, ECO:0000305|PubMed:15700135}
ENPP2 is also known as ATX, ATX-X, AUTOTAXIN, LysoPLD, NPP2, PD-IALPHA, PDNP2.
