Kv2.1 and electrically silent Kv6.1 potassium channel subunits combine and express a novel current.
Heteromultimer formation between Kv potassium channel subfamilies with the production of a novel current is reported for the first time. Protein-protein interactions between Kv2.1 and electrically silent Kv6.1 alpha-subunits were detected using two microelectrode voltage clamp and yeast two-hybrid measurements. Amino terminal portions of Kv6.1 were unable to form homomultimers but interacted specifically with amino termini of Kv2.1. Xenopus oocytes co-injected with Kv6.1 and Kv2.1 cRNAs exhibited a novel current with decreased rates of deactivation, decreased sensitivity to TEA block, and a hyperpolarizing shift of the half maximal activation potential when compared to Kv2.1. Our results indicate that Kv channel subfamilies can form heteromultimeric channels and, for the first time, suggest a possible functional role for the Kv6 subfamily.
Post
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MA
Rammelkamp Research Center, Case Western Reserve University, Cleveland, OH 44109, USA. mpost@research.mhmc.org
Kirsch
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Brown
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D000818:Animals; D018408:Patch-Clamp Techniques; D026902:Potassium Channel Blockers; D015221:Potassium Channels / Q000502:physiology*; D011993:Recombinant Fusion Proteins / Q000502:physiology; D051669:Shab Potassium Channels; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014981:Xenopus
C496988:KCNB1 protein, human; D026902:Potassium Channel Blockers; D015221:Potassium Channels; D011993:Recombinant Fusion Proteins; D051669:Shab Potassium Channels; D013757:Tetraethylammonium Compounds; D019789:Tetraethylammonium