TY - JOUR
T1 - Pertussis-toxin-sensitive Gα subunits selectively bind to C-terminal domain of neuronal GIRK channels
T2 - Evidence for a heterotrimeric G-protein-channel complex
AU - Clancy, Sinead M.
AU - Fowler, Catherine E.
AU - Finley, Melissa
AU - Suen, Ka Fai
AU - Arrabit, Christine
AU - Berton, Frédérique
AU - Kosaza, Tohru
AU - Casey, Patrick J.
AU - Slesinger, Paul A.
N1 - Funding Information:
We thank M. Lazdunski for providing the GIRK2a cDNA, H. Lester for providing the human M2 muscarinic receptor, S. and Y. Nakajima for HA-GIRK2, L. Jan for GABAB receptors, J. Hepler for H6-RGS2, R. Kass for advice on IP and L. Cervini, R. Kaiser, C. Miller and W. Low for peptide synthesis and characterization. This work was made possible by financial support from the Sloan Foundation (P.A.S.), McKnight Endowment for Neuroscience (P.A.S.), the Fritz-Burns Foundation (P.A.S.), the National Institute of General Medicine (R01-GM55717, P.JK) and the National Institute of Neurological Disorders and Stroke (R01 NS37682, P.A.S.). Postdoctoral support was provided by the Giannini Family Foundation (M.F.) and NARSAD (F.B).
PY - 2005/2
Y1 - 2005/2
N2 - Neuronal G-protein-gated inwardly rectifying potassium (Kir3; GIRK) channels are activated by G-protein-coupled receptors that selectively interact with PTX-sensitive (Gαi/o) G proteins. Although the G βγ dimer is known to activate GIRK channels, the role of the Gαi/o subunit remains unclear. Here, we established that Gαo subunits co-immunoprecipitate with neuronal GIRK channels. In vitro binding studies led to the identification of six amino acids in the GIRK2 C-terminal domain essential for Gαo binding. Further studies suggested that the Gαi/oβγ heterotrimer binds to the GIRK2 C-terminal domain via Gα and not G βγ. Gαi/o binding-impaired GIRK2 channels exhibited reduced receptor-activated currents, but retained normal ethanol- and Gβγ-activated currents. Finally, PTX-insensitive G αq or Gαs subunits did not bind to the GIRK2 C-terminus. Together, these results suggest that the interaction of PTX-sensitive Gαi/o subunit with the GIRK2 C-terminal domain regulates G-protein receptor coupling, and may be important for establishing specific Gαi/o signaling pathways.
AB - Neuronal G-protein-gated inwardly rectifying potassium (Kir3; GIRK) channels are activated by G-protein-coupled receptors that selectively interact with PTX-sensitive (Gαi/o) G proteins. Although the G βγ dimer is known to activate GIRK channels, the role of the Gαi/o subunit remains unclear. Here, we established that Gαo subunits co-immunoprecipitate with neuronal GIRK channels. In vitro binding studies led to the identification of six amino acids in the GIRK2 C-terminal domain essential for Gαo binding. Further studies suggested that the Gαi/oβγ heterotrimer binds to the GIRK2 C-terminal domain via Gα and not G βγ. Gαi/o binding-impaired GIRK2 channels exhibited reduced receptor-activated currents, but retained normal ethanol- and Gβγ-activated currents. Finally, PTX-insensitive G αq or Gαs subunits did not bind to the GIRK2 C-terminus. Together, these results suggest that the interaction of PTX-sensitive Gαi/o subunit with the GIRK2 C-terminal domain regulates G-protein receptor coupling, and may be important for establishing specific Gαi/o signaling pathways.
UR - https://www.scopus.com/pages/publications/13444254031
U2 - 10.1016/j.mcn.2004.10.009
DO - 10.1016/j.mcn.2004.10.009
M3 - Article
C2 - 15691717
AN - SCOPUS:13444254031
SN - 1044-7431
VL - 28
SP - 375
EP - 389
JO - Molecular and Cellular Neuroscience
JF - Molecular and Cellular Neuroscience
IS - 2
ER -