Journal article

Functional coupling of mu-receptor-G alpha i-tethered proteins in AtT20 cells

Billy C Chieng, David J Lee, Yan P Du, Peregrine B Osborne, MacDonald J Christie, Dominique Massotte



Opioid efficacy on mu-receptor may be influenced by various Gi/o-G-protein subunits interacting with intracellular face of receptor. Pertussis toxin-insensitive Galphai1 and Galphai2 subunits tethered with mu-receptor were stably transfected into AtT20 cells to (i) determine coupling of different alpha-subunits on opioid efficacy, and (ii) determine coupling to downstream effectors, for example, calcium and potassium channels. After pertussis toxin, stimulation of [35S]GTP-gamma-S incorporation persisted. Both constructs were able to couple to native calcium and potassium channels, with endomorphins 1 and 2 equally effective. However, pertussis toxin abolished opioid actions on calcium and p..

View full abstract

University of Melbourne Researchers


Awarded by NH MRC Australia

Awarded by National Institute on Drug Abuse

Funding Acknowledgements

This study was supported by NH & MRC Australia project grant #302087 to B.C.C and M.J.C., and National Institute on Drug Abuse Grant DA12926-01 to M.J.C. M.J.C. is a NH & MRC Senior Principal Research Fellow (511914).