Pituitary adenylate cyclase-activating polypeptide type I receptor also known as PAC₁, is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the ADCYAP1R1 gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. This receptor binds pituitary adenylate cyclase activating peptide

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.-...

.

PAC₁ is a membrane-associated protein and shares significant homology with members of the G-protein coupled class B glucagon

Glucagon receptor

The glucagon receptor is a 62 kDa protein that is activated by glucagon and is a member of the class B G-protein coupled family of receptors, coupled to G alpha i, Gs and to a lesser extent G alpha q. Stimulation of the receptor results in activation of adenylate cyclase and increased levels of...

/secretin receptor

Secretin receptor

Human secretin receptor is a G protein-coupled receptor which binds secretin and is the leading member of the class B GPCR subfamily.-Interactions:...

 family. This receptor mediates diverse biological actions of adenylate cyclase activating polypeptide 1 and is positively coupled to adenylate cyclase. Alternative splicing

Alternative splicing

Alternative splicing is a process by which the exons of the RNA produced by transcription of a gene are reconnected in multiple ways during RNA splicing...

 of two exons of this gene generates four major splice variants, but their full-length nature has not been determined. PAC₁ is expressed in the adrenal medulla

Adrenal medulla

The adrenal medulla is part of the adrenal gland. It is located at the center of the gland, being surrounded by the adrenal cortex. It is the innermost part of the adrenal gland, consisting of cells that secrete epinephrine , norepinephrine , and a small amount of dopamine in response to...

, pancreatic acini

Pancreas

The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...

, uterus

Uterus

The uterus or womb is a major female hormone-responsive reproductive sex organ of most mammals including humans. One end, the cervix, opens into the vagina, while the other is connected to one or both fallopian tubes, depending on the species...

, myenteric plexus and brain

Brain

The brain is the center of the nervous system in all vertebrate and most invertebrate animals—only a few primitive invertebrates such as sponges, jellyfish, sea squirts and starfishes do not have one. It is located in the head, usually close to primary sensory apparatus such as vision, hearing,...

. It is also expressed in the trigeminal

Trigeminal ganglion

The trigeminal ganglion is a sensory ganglion of the trigeminal nerve that occupies a cavity in the dura mater, covering the trigeminal impression near the apex of the petrous part of the temporal bone.-Relations:It is somewhat crescentic in shape, with its convexity...

, otic

Otic ganglion

The otic ganglion is a small, oval shaped, flattened parasympathetic ganglion of a reddish-gray color, located immediately below the foramen ovale in the infratemporal fossa. It gives innervation to the parotid gland for salivation....

 and superior cervical ganglia

Superior cervical ganglion

The superior cervical ganglion , the largest of the cervical ganglia, is placed opposite the second and third cervical vertebræ. It contains neurons that supply sympathetic innervation to the face....

(prejunctional) and cerebral arteries (postjunctional).