Retinoic acid-induced protein 3 is a protein that in humans is encoded by the GPRC5A gene. This gene and its encoded mRNA was first identified as a phorbol ester-induced gene, and named Phorbol Ester Induced Gen 1 (PEIG-1); two years later it was rediscovered as a retinoic acid-inducible gene, and named Retinoic Acid-Inducible Gene 1 (RAIG1). Its encoded protein was later named Retinoic acid-induced protein 3.

This gene encodes a member of the type 3 G protein-coupled receptor family, characterized by the signature 7-transmembrane domain motif. The encoded protein may be involved in interaction between retinoic acid and G protein signalling pathways. Retinoic acid plays a critical role in development, cellular growth, and differentiation. This gene may play a role in embryonic development and epithelial cell differentiation. Tryptamine and other indole related chemicals produced by gut microflora bind and activate the receptor.

GPRC5A is one of only a handful of genes known in the literature that are post-transcriptionally controlled by miRNAs through their 5'UTR.

GPRC5A is dysregulated in many human cancers and in other diseases.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.