Receptor activity-modifying protein (RAMP) (RAMP)

Receptor activity-modifying proteins (RAMPs) are a family of three single-pass transmembrane proteins (RAMP1, RAMP2, and RAMP3) that are essential for the functional expression and pharmacological diversity of certain G protein-coupled receptors (GPCRs) (PMID: 9624044). They do not typically bind ligands on their own but instead form heterodimers with partner receptors, most notably the Calcitonin receptor-like receptor (CRLR) and the Calcitonin receptor (CTR) (UniProt: O60894). The specific RAMP isoform associated with CRLR determines the resulting receptor's identity: RAMP1 creates the Calcitonin Gene-Related Peptide (CGRP) receptor, while RAMP2 and RAMP3 create Adrenomedullin receptors AM1 and AM2, respectively (PubMed: 29635024). This makes RAMPs, particularly RAMP1, critical therapeutic targets in migraine, where blocking CGRP signaling via the RAMP1/CRLR complex has led to the development of monoclonal antibodies like erenumab and small-molecule gepants (StatPearls: NBK553135). Beyond migraine, RAMPs play vital roles in cardiovascular homeostasis, lymphatic development, and the regulation of inflammatory responses (PubMed: 30115654). Their ability to modulate receptor trafficking and signaling makes them versatile components of the cellular signaling machinery and attractive targets for precision medicine.

Other names

RAMPRAMP1RAMP2RAMP3Receptor (G protein-coupled) activity modifying proteinCRLR-modifying protein

RAMPs act as pharmacological switches that determine the ligand specificity of GPCRs, such as converting CRLR into a CGRP receptor (via RAMP1) or an adrenomedullin receptor (via RAMP2/3). Therapeutic agents like erenumab are monoclonal antibodies that bind to the extracellular domain of the RAMP1/CRLR complex to prevent CGRP binding, while small-molecule antagonists (gepants) competitively inhibit the same receptor complex to treat or prevent migraine (FDA: Aimovig; PMID: 31034773). Additionally, RAMPs facilitate the trafficking of these receptors from the endoplasmic reticulum to the plasma membrane (UniProt: O60894).