Lysophosphatidic acid receptor 4 (LPAR4)

Lysophosphatidic acid receptor 4 (LPAR4) is a member of the G protein-coupled receptor (GPCR) superfamily, specifically known as P2Y9 or GPR23, and is structurally distinct from the Edg family LPA receptors[2][5]. It mediates signaling triggered by lysophosphatidic acid (LPA), a bioactive phospholipid involved in diverse cellular responses. LPAR4 is coupled to multiple G proteins (Gαs, Gαi, Gαq, Gα12/13), and has a broad tissue expression with highest levels in the human ovary and lower expression in thymus, pancreas, colon, brain, and cardiovascular tissues[1][4]. Functionally, LPAR4 acts as a negative regulator of LPA-induced cell migration and invasion—counterbalancing the effects of other LPA receptors such as LPAR1—and participates in cell aggregation, vascular development, and maintenance of the hematopoietic stem/progenitor cell niche in bone marrow[1][4][5][8]. Alterations in LPAR4 activity have roles in pathological processes including cancer, cardiovascular, fibrotic, and neurodegenerative diseases, with emerging interest as a therapeutic target, though selective pharmacological modulators are still in early development[1][3][8].

Other names

P2Y9GPR23LPA4

G protein-mediated signaling (coupling to Gαs, Gαi, Gαq, Gα12/13); Negative regulation of cell motility and invasion (antagonizing LPAR1 action); Downstream modulation of PI3K/Akt, Rac, and Rho pathways[1][5]