The dopaminergic receptor D1 activates and the muscarinic acetylcholine receptor (mAChR) M4 inhibits adenylyl cyclase (AC) and thereby cAMP production through the trimeric Gαs and Gαi/o proteins, respectively (Wess et al, 2007). D1 and M4 are coexpressed in striatal output neurons, where M4 antagonizes D1 signalling as recently pinpointed by conditional M4 knockout in D1-expressing neurons (Jeon et al, 2010). Closely following on the heels of this article, Guo et al (2010) report in this issue that CaMKII binds and phosphorylates M4 upon Ca2+ influx to augment the antagonistic action of M4 on D1 signalling and on D1-mediated, cocaine-triggered hyperlocomotion.
ASJC Scopus subject areas
- Molecular Biology
- Biochemistry, Genetics and Molecular Biology(all)
- Immunology and Microbiology(all)