Receptor for lysophosphatidic acid (LPA)(PubMed:11278944). Plays a role in the reorganization of the actin cytoskeleton, cell migration, differentiation and proliferation, and thereby contributes to the responses to tissue damage and infectious agents. Activates downstream signaling cascades via the G(i)/G(o), G(12)/G(13), and G(q) families of heteromeric G proteins. Signaling inhibits adenylyl cyclase activity and decreases cellular cAMP levels (PubMed:11278944). Signaling triggers an increase of cytoplasmic Ca(2+) levels. Signaling leads to the activation of phospholipase C (PLC) and the formation of inositol 1,4,5-trisphosphate. Signaling mediates activation of down-stream MAP kinases (By similarity). Contributes to the regulation of cell shape (PubMed:11278944). Promotes Rho-dependent reorganization of the actin cytoskeleton in neuronal cells and neurite retraction. Promotes the activation of Rho and the formation of actin stress fibers. Promotes formation of lamellipodia at the leading edge of migrating cells via activation of Rac. Through its function as lysophosphatidic acid receptor, plays a role in chemotaxis and cell migration, including responses to injury and wounding. Promotes cell proliferation in response to lysophosphatidic acid (By similarity). Prior to LPA treatment found predominantly at the cell surface. Internalized after LPA treatment. Expressed at high levels in oocytes and at lower levels in brain and spinal cord. Below detection level in lung, heart, kidney, liver, muscle, stomach, and intestine. Belongs to the G-protein coupled receptor 1 family.