Receptor Activity Modifying Protein 3 (RAMP3)

Receptor activity-modifying proteins (RAMPs), such as RAMP3, modify G protein-coupled receptor (GPCR) signaling by modulating ligand binding affinity, trafficking, and second messenger pathways. RAMPs appear to have overlapping effects on the GPCRs with which they interact.

RAMP1, RAMP2, and RAMP3 share 31% amino acid identity and 56% amino acid similarity. Sequence analysis predicted that RAMP3 is a 148-amino acid type I transmembrane protein containing 4 conserved cysteine residues in the N terminus and a dibasic pair of residues, like RAMP1 but unlike RAMP2, in the C terminus. Northern blot analysis detected strong expression of a 1.3-kb RAMP3 transcript in lung, breast, immune system tissues, and fetal tissues.