PACAP is a neuropeptide involved in diverse array of physiological processes through activating the PACAP subfamily of class B1 G protein-coupled receptors: VIP receptor 1 (VIPR1), VIP receptor 2 (VIPR2), and PACAP type I receptor (ADCYAP1R1) (PubMed:11175907, PubMed:23800469, PubMed:32047270, PubMed:32004469, PubMed:36385145). Exerts neuroprotective and general cytoprotective effects due to anti- apoptotic, anti-inflammatory, and antioxidant actions (PubMed:23800469). Promotes neuron projection development through the RAPGEF2/Rap1/B-Raf/ERK pathway (PubMed:23800469). In chromaffin cells, induces long-lasting increase of intracellular calcium concentrations and neuroendocrine secretion (By similarity). Involved in the control of glucose homeostasis, induces insulin secretion by pancreatic beta cells (By similarity). PACAP exists in two bioactive forms from proteolysis of the same precursor protein, PACAP27 and PACAP38, which differ by eleven amino acid residues in the C-terminus (PubMed:32047270, PubMed:32004469). {ECO:0000250|UniProtKB:O70176, ECO:0000250|UniProtKB:P13589, ECO:0000269|PubMed:11175907, ECO:0000269|PubMed:23800469, ECO:0000269|PubMed:32004469, ECO:0000269|PubMed:32047270, ECO:0000269|PubMed:36385145}. This is the function of ENSG00000141433 (ADCYAP1, adenylate cyclase activating polypeptide 1).