Phospholipase A and acyltransferase 4 is an enzyme that in humans is encoded by the PLAAT4 gene (previously RARRES3). This enzyme has also been called retinoic acid receptor responder 3, since its expression can be induced by retinoic acid (active vitamin A).
Retinoids exert biologic effects such as potent growth inhibitory and cell differentiation activities and are used in the treatment of hyperproliferative dermatological diseases. These effects are mediated by specific nuclear receptor proteins that are members of the steroid and thyroid hormone receptor superfamily of transcriptional regulators. RARRES1, RARRES2, and RARRES3 are genes whose expression is upregulated by the synthetic retinoid tazarotene. RARRES3 is thought act as a tumor suppressor or growth regulator.
