RAMP1 (receptor-activity-modifying protein) is a member of the RAMP family of single-transmembrane-domain proteins which consist of an N-terminal extracellular domain, a transmembrane region, and a short intracellular C-terminal tail. RAMPs are required to transport calcitonin-receptor-like receptor (CRLR) to the plasma membrane. CRLR, a G protein-coupled receptor, can function as either a calcitonin gene-related peptide (CGRP) receptor or an adrenomedullin receptor, depending on which members of the RAMP family are expressed. RAMP1 transports the CRLR to the plasma membrane and then remains associated with it to function as a terminally glycosylated CGRP receptor, while RAMP2 and RAMP3 transfer the CRLR to the cell surface to generate receptors that are preferentially selective for adrenomedullin. RAMP1 can form a homodimer, which migrates at 30-37 kDa on SDS-PAGE. (PMID: 9620797; 16188935; 12051717;PMID: 18384073)