Conversion of an instantaneous activating K⁺ channel into a slow activating inward rectifier

Authors

Dirk Baumeister, Technische Universität Darmstadt
Brigitte Hertel, Institute of Botany, Technische Universität Darmstadt, Schnittspahnstrasse 3, D-64287 Darmstadt, Germany
Indra Schroeder, Technische Universität Darmstadt
Sabrina Gazzarrini, Università degli Studi di Milano
Stefan M. Kast, Technische Universität DortmundFollow
James L. Van Etten, University of Nebraska-LincolnFollow
Anna Moroni, Università degli Studi di MilanoFollow
Gerhard Thiel, Technische Universität Darmstadt, GermanyFollow

Date of this Version

2017

Document Type

Article

Citation

FEBS Letters 591 (2017) 295–303

doi:10.1002/1873-3468.12536

PMID: 27995608

https://www.ncbi.nlm.nih.gov/pubmed/27995608

Comments

Copyright 2016 Federation of European Biochemical Societies

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Abstract

The miniature channel, Kcv, is a structural equivalent of the pore of all K⁺ channels. Here, we follow up on a previous observation that a largely voltage-insensitive channel can be converted into a slow activating inward rectifier after extending the outer transmembrane domain by one Ala. This gain of rectification can be rationalized by dynamic salt bridges at the cytosolic entrance to the channel; opening is favored by voltage-sensitive formation of salt bridges and counteracted by their disruption. Such latent voltage sensitivity in the pore could be relevant for the understanding of voltage gating in complex Kv channels.