Non-Edg Family LPA Receptors: The Cutting Edge of LPA Research

Lysophosphatidic acid (LPA) was initially known to function through three Edg family G protein-coupled receptors (LPA1, LPA2, and LPA3). However, the identification of a fourth receptor, LPA4, which is structurally distinct from the Edg family, led to the discovery of two more receptors, LPA5 and LPA6, homologous to LPA4. These non-Edg family LPA receptors expanded the understanding of LPA's diverse roles, including vascular development, platelet activation, and hair growth. The review summarized the identification, intracellular signaling, and biological functions of these novel LPA receptors.