Tg(Ins2-Chrm3*)QJwe

This transgene was designed to have (from 5' to 3') a 650 bp rat insulin 2 (Ins2; RIP II) promoter fragment, a hemagglutinin epitope tag (HA), the rhM3Dq coding sequence (R-q; described below), and untranslated human growth hormone sequences (containing transcriptional termination, polyadenylation and splicing signals). The transgene is expressed in pancreatic beta cells.The rhM3Dq (or R-q) sequence is a Gq-coupled rat/human chimer M3 muscarinic DREADD (designer receptor exclusively activated by designer drug). To create the rhM3Dq sequence, a 924 bp sequence of the wildtype rat muscarinic 3 receptor (Chrm3; M3R) was replaced with the human M3R sequences containing the Y149C and A239G amino acid substitutions (corresponding to rat Y148C and A238G). These mutations abolish receptor affinity for the native ligand, acetylcholine (ACh), but allow receptor binding and subsequent activation by the small drug-like molecule clozapine-N-oxide (CNO). (J:154657)