Document Detail


KCNQ1 channels sense small changes in cell volume.
MedLine Citation:
PMID:  12702742     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Many important physiological processes involve changes in cell volume, e.g. the transport of salt and water in epithelial cells and the contraction of cardiomyocytes. In this study, we show that voltage-gated KCNQ1 channels, which are strongly expressed in epithelial cells or cardiomyocytes, and KCNQ4 channels, expressed in hair cells and the auditory tract, are tightly regulated by small cell volume changes when co-expressed with aquaporin 1 water-channels (AQP1) in Xenopus oocytes. The KCNQ1 and KCNQ4 current amplitudes precisely reflect the volume of the oocytes. By contrast, the related KCNQ2 and KCNQ3 channels, which are prominently expressed in neurons, are insensitive to cell volume changes. The sensitivity of the KCNQ1 and KCNQ4 channels to cell volume changes is independent of the presence of the auxiliary KCNE1-3 subunits, although modulated by KCNE1 in the case of KCNQ1. Incubation of the oocytes in cytochalasin D and experiments with truncated KCNQ1 channels suggest that KCNQ1 channels sense cell volume changes through interactions between the cytoskeleton and the N-terminus of the channel protein. From our results we propose that KCNQ1 and KCNQ4 channels play an important role in cell volume control, e.g. during transepithelial transport of salt and water.
Authors:
Morten Grunnet; Thomas Jespersen; Nanna MacAulay; Nanna K Jørgensen; Nicole Schmitt; Olaf Pongs; Søren-Peter Olesen; Dan A Klaerke
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2003-04-17
Journal Detail:
Title:  The Journal of physiology     Volume:  549     ISSN:  0022-3751     ISO Abbreviation:  J. Physiol. (Lond.)     Publication Date:  2003 Jun 
Date Detail:
Created Date:  2003-06-02     Completed Date:  2004-01-22     Revised Date:  2013-06-09    
Medline Journal Info:
Nlm Unique ID:  0266262     Medline TA:  J Physiol     Country:  England    
Other Details:
Languages:  eng     Pagination:  419-27     Citation Subset:  IM    
Affiliation:
Department of Medical Physiology, The Panum Institute, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.
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MeSH Terms
Descriptor/Qualifier:
Animals
Aquaporin 1
Aquaporins / metabolism
Cell Size / physiology*
Electrophysiology
KCNQ Potassium Channels
KCNQ1 Potassium Channel
Oocytes
Potassium Channels / chemistry,  physiology*
Potassium Channels, Voltage-Gated*
Xenopus laevis
Chemical
Reg. No./Substance:
0/Aquaporins; 0/KCNQ Potassium Channels; 0/KCNQ1 Potassium Channel; 0/KCNQ4 protein, human; 0/Potassium Channels; 0/Potassium Channels, Voltage-Gated; 0/potassium channel protein I(sk); 146410-94-8/Aquaporin 1
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