Additional signals from VPAC/PAC family receptors

Abstract

The receptors for the neuropeptides vasoactive intestinal polypeptide and pituitary adenylate cyclase-activating polypeptide are strong activators of adenylate cyclase, but recent evidence suggests that they can elicit a number of additional intracellular signals. Some of these are likely to be downstream of the conventional adenylate cyclase pathway, but it is now clear that others reflect novel primary coupling events of the receptors.

Location and Function of VPAC1, VPAC2 and NPR-C Receptors in VIP-Induced Vasodilation of Porcine Basilar Arteries

“…Within the group II secretin receptor G protein-coupled receptor family, the VPAC 1 and VPAC 2 receptors have been identified, cloned (Harmar et al, 1998) and are considered to be the main physiological receptors that mediate the effects of VIP. Members of this family couple to the production of cAMP, and are capable of activating additional signalling pathways (McCulloch et al, 2002). Both VPAC 1 and VPAC 2 receptors have been shown to be expressed in equal amounts in human cerebral arteries regardless of endothelium; however, their location remains undetermined (Knutsson and Edvinsson, 2002).…”

Modulation of NMDA Receptors by Pituitary Adenylate Cyclase Activating Peptide in CA1 Neurons Requires Gαq, Protein Kinase C, and Activation of Src

“…The pituitary adenylate cyclase activating peptide (PACAP) receptor is best known for its ability to stimulate adenylate cyclases, cAMP production, and PKA (Ohtaki et al, 1993;McCulloch et al, 2002) but also signals through G q/11 to phospholipase C (PLC) (Spengler et al, 1993;McCulloch et al, 2002). PACAP1 receptors (PAC 1 Rs), specific for PACAP, are expressed predominantly in the brain, whereas VPAC receptors, which bind both VIP and PACAP, are more common in the periphery (Hashimoto et al, 1993).…”

Suppression of Vasoactive Intestinal Polypeptide in the Suprachiasmatic Nucleus Leads to Aging-Like Alterations in cAMP Rhythms and Activation of Gonadotropin-Releasing Hormone Neurons

“…First, VIP neurons in the SCN directly innervate GnRH neurons in the rostral preoptic nucleus (rMPN) (van der Beek et al, 1997;Horvath et al, 1998). Second, GnRH neurons express the VIP/ PACAP receptor subtype 2 (VPAC 2 ) receptor subtype (Smith et al, 2000), which is coupled to the stimulatory G-protein (Gs) signal transduction pathway that leads to an accumulation of cAMP (McCulloch et al, 2002). Interestingly, Chappell et al (2000) reported that cAMP levels in the anteroventral periven-tricular nucleus (AVPV) exhibit a diurnal rhythm that is markedly analogous to the rhythm of VIP.…”