Autotaxin in embryonic development.

Autotaxin (ATX) is a secreted lysophospholipase D that generates the multifunctional lipid mediator lysophosphatidic acid (LPA). LPA signals through six distinct G protein-coupled receptors, acting alone or in concert to activate multiple effector pathways. The ATX–LPA signaling axis is implicated in a remarkably wide variety of physiological and pathological processes and plays a vital role in embryonic development. Disruption of the ATX-encoding gene (Enpp2) in mice results in intrauterine death due to vascular defects in the extra-embryonic yolk sac and embryo proper. In addition, Enpp2 (−/−) embryos show impaired neural development. The observed angiogenic defects are attributable, at least in part, to loss of LPA signaling through the Gα12/13-linked RhoA-ROCK-actin remodeling pathway. Studies in zebrafish also have uncovered a dual role for ATX in both vascular and neural development; furthermore, they point to a key role for ATX–LPA signaling in the regulation of left–right asymmetry. Here we discuss our present understanding of the role of ATX–LPA signaling in vertebrate development. This article is part of a Special Issue entitled Advances in Lysophospholipid Research.