Novel insights into the function of β-cell M3 muscarinic acetylcholine receptors: therapeutic implications

Impaired function of pancreatic beta-cells is one of the hallmarks of type 2 diabetes. beta-cell function is regulated by the activity of many hormones and neurotransmitters, which bind to specific cell surface receptors. The M-3 muscarinic acetylcholine receptor (M3R) belongs to the superfamily of G protein-coupled receptors and, following ligand dependent activation, selectively activates G proteins of the G(q/11) family. Recent studies with M3R mutant mice strongly suggest that beta-cell M3Rs play a central role in promoting insulin release and maintaining correct glucose homeostasis. In this review, we highlight recent studies indicating that beta-cell M3Rs and components of downstream signaling pathways might represent promising new targets for the treatment of type 2 diabetes.