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The Role of Members of the Pertussis Toxin-sensitive Family of G Proteins in Coupling Receptors to the Activation of the G Protein-gated Inwardly Rectifying Potassium Channel

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Specialty Science
Date 2000 Apr 26
PMID 10779550
Citations 30
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Abstract

Inwardly rectifying potassium (K(+)) channels gated by G proteins (Kir3.x family) are widely distributed in neuronal, atrial, and endocrine tissues and play key roles in generating late inhibitory postsynaptic potentials, slowing the heart rate and modulating hormone release. They are directly activated by G(betagamma) subunits released from G protein heterotrimers of the G(i/o) family upon appropriate receptor stimulation. Here we examine the role of isoforms of pertussis toxin (PTx)-sensitive G protein alpha subunits (G(ialpha1-3) and G(oalphaA)) in mediating coupling between various receptor systems (A(1), alpha(2A), D(2S), M(4), GABA(B)1a+2, and GABA(B)1b+2) and the cloned counterpart of the neuronal channel (Kir3.1+3.2A). The expression of mutant PTx-resistant G(i/oalpha) subunits in PTx-treated HEK293 cells stably expressing Kir3.1+3.2A allows us to selectively investigate that coupling. We find that, for those receptors (A(1), alpha(2A)) known to interact with all isoforms, G(ialpha1-3) and G(oalphaA) can all support a significant degree of coupling to Kir3.1+3.2A. The M(4) receptor appears to preferentially couple to G(ialpha2) while another group of receptors (D(2S), GABA(B)1a+2, GABA(B)1b+2) activates the channel predominantly through G(betagamma) liberated from G(oA) heterotrimers. Interestingly, we have also found a distinct difference in G protein coupling between the two splice variants of GABA(B)1. Our data reveal selective pathways of receptor activation through different G(i/oalpha) isoforms for stimulation of the G protein-gated inwardly rectifying K(+) channel.

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References
1.
Hedin K, Lim N, Clapham D . Cloning of a Xenopus laevis inwardly rectifying K+ channel subunit that permits GIRK1 expression of IKACh currents in oocytes. Neuron. 1996; 16(2):423-9. DOI: 10.1016/s0896-6273(00)80060-4. View

2.
Leaney J, Milligan G, Tinker A . The G protein alpha subunit has a key role in determining the specificity of coupling to, but not the activation of, G protein-gated inwardly rectifying K(+) channels. J Biol Chem. 2000; 275(2):921-9. DOI: 10.1074/jbc.275.2.921. View

3.
Wise A, Rees S, Lee M, Milligan G . Interactions of the alpha2A-adrenoceptor with multiple Gi-family G-proteins: studies with pertussis toxin-resistant G-protein mutants. Biochem J. 1997; 321 ( Pt 3):721-8. PMC: 1218128. DOI: 10.1042/bj3210721. View

4.
Kaupmann K, Huggel K, Heid J, Flor P, Bischoff S, Mickel S . Expression cloning of GABA(B) receptors uncovers similarity to metabotropic glutamate receptors. Nature. 1997; 386(6622):239-46. DOI: 10.1038/386239a0. View

5.
Huang C, Jan Y, Jan L . Binding of the G protein betagamma subunit to multiple regions of G protein-gated inward-rectifying K+ channels. FEBS Lett. 1997; 405(3):291-8. DOI: 10.1016/s0014-5793(97)00197-x. View