Pituitary adenylate cyclase-activating peptide


Pituitary adenylate cyclase-activating polypeptide also known as PACAP is a protein that in humans is encoded by the ADCYAP1 gene. PACAP is similar to vasoactive intestinal peptide. One of its effects is to stimulate enterochromaffin-like cells. It binds to vasoactive intestinal peptide receptor and to the PACAP receptor.

Function

This gene encodes adenylate cyclase-activating polypeptide 1. Mediated by adenylate cyclase-activating polypeptide 1 receptors, this polypeptide stimulates adenylate cyclase and subsequently increases the cAMP level in target cells. Adenylate cyclase-activating polypeptide 1 not only is a hypophysiotropic hormone, but also functions as a neurotransmitter and neuromodulator. In addition, it plays a role in paracrine and autocrine regulation of certain types of cells. This gene is composed of five exons. Exons 1 and 2 encode the 5' UTR and signal peptide, respectively; exon 4 encodes an adenylate cyclase-activating polypeptide 1-related peptide; and exon 5 encodes the mature peptide and 3' UTR. This gene encodes three different mature peptides, including two isotypes: a shorter form and a longer form.
A version of this gene has been associated with post-traumatic stress disorder in women. This disorder involves a maladaptive psychological response to traumatic, i.e. existence-threatening, events. Ressler et al. identified an association of a SNP in the gene coding for pituitary adenylate cyclase-activating polypeptide, implicating this peptide and its receptor in PTSD.

Headache Disorders

Research has shown that administration of intravenous PACAP-38 triggers delayed "migraine-like headaches" in most subjects who experience migraine headaches. Treatments with monoclonal antibodies are being developed targeting PACAP or its receptors for the treatment of primary headache disorders. These include: AMG‐301 developed by Amgen Inc., which targets the PAC1 receptor and has completed phase II trials; and ALD1910, developed by Alder BioPharmaceuticals, which targets the peptide and began a phase I study in October 2019.

Interactions

Pituitary adenylate cyclase-activating peptide has been shown to interact with secretin receptor.