Subunit stoichiometry of a heteromultimeric G protein-coupled inward-rectifier K+ channel.
We investigated the stoichiometry of the heteromultimeric G protein-coupled inward-recitfier K+ channel (GIRK) formed from GIRK1 and GIRK4 subunits. Multimeric GIRK constructs with several concatenated channel subunits were expressed in Xenopus oocytes. Coexpression of various trimeric constructs with different monomers clearly showed that the functional channel has stoichiometry (GIRK1)2(GIRK4)2. Efforts to establish a preferred arrangement of subunits around the channel pore suggest that more than one arrangement may be viable.
Silverman
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SK
De&aChemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA. Lester@Caltech.edu
Lester
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Dougherty
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D000818:Animals; D019204:GTP-Binding Proteins / Q000502:physiology*; D015640:Ion Channel Gating; D046911:Macromolecular Substances; D016376:Oligonucleotides, Antisense / Q000737:chemistry; D009865:Oocytes; D018408:Patch-Clamp Techniques; D015221:Potassium Channels / Q000737:chemistry*; D011994:Recombinant Proteins; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D014982:Xenopus laevis
D046911:Macromolecular Substances; D016376:Oligonucleotides, Antisense; D015221:Potassium Channels; D011994:Recombinant Proteins; D019204:GTP-Binding Proteins