PAC1-R
PAC1-R (ADCYAP1R1) is the high-affinity receptor for pituitary adenylate cyclase-activating polypeptide (PACAP), preferring PACAP over VIP by orders of magnitude. This class B GPCR couples to Gs and, depending on splice variant, also to Gq/PLC, generating both cAMP and calcium signals. PAC1-R is expressed widely in the nervous system, adrenal medulla and germ cells, and mediates neuroprotection, stress-axis regulation, neuroendocrine secretion and circadian phase-shifting. PACAP/PAC1 signaling has been implicated in migraine, post-traumatic stress disorder and neurodegeneration, making the receptor a drug-discovery focus. Recombinant PAC1-R enables variant-specific binding and functional assays of PACAP ligands.
