Receptor for corticotropin (ACTH). This receptor is mediated by G proteins which activate adenylate cyclase (cAMP). Interacts with MRAP; increasing ligand-sensitivity and generation of cAMP. Interacts with MRAP2; competing with MRAP for binding to MC2R and impairing the binding of corticotropin (ACTH) (By similarity). Expressed in skin and adrenal gland tissues. Belongs to the G-protein coupled receptor 1 family.