Melanocortin 2 receptor accessory protein 2 is a protein that in humans is encoded by the MRAP2 gene.[5] MRAP2 is a transmembrane accessory protein to a family of five receptors called the melanocortin receptors (MC1-5). Human genome sequencing analysis led to the discovery of MRAP2,[6] Human MRAP2 gene is located in chromosome 6q14.3, a different chromosomal location from that of human MRAP which is a paralogy to MRAP2. MRAP2 is thought to be involved in regulating the expression of the melanocortin (MC1-5) and some non-melanocortin receptors such as ghrelin receptor (GHSR-1a), orexin (OX1R) receptor and prokineticin receptor (PKR-1).[7][8]
MRAP2 was found first in the adrenal gland and the brain.[6] However, the Human protein Atlas/ RNA-seq analysis data of human genome detected MRAP2 in other tissues such as ovary, endometrium, testis, digestive tract, pituitary gland and skin.[6][9][7]
The MRAP2 function was found to be associated with regulating appetite and energy expenditure. This is through regulating different receptors involved in the brain circuit regulating those two functions. Such receptors include MC4, MC3, GHSR-1a, PKR-1 and OX1R.[6][8][7]
