TY - JOUR
T1 - KCNQ1 channels sense small changes in cell volume.
AU - Grunnet, Morten
AU - Jespersen, Thomas
AU - MacAulay, Nanna
AU - Jørgensen, Nanna K
AU - Schmitt, Nicole
AU - Pongs, Olaf
AU - Olesen, Søren-Peter
AU - Klærke, Dan Arne
N1 - Keywords: Animals; Aquaporin 1; Aquaporins; Cell Size; Electrophysiology; KCNQ Potassium Channels; KCNQ1 Potassium Channel; Oocytes; Potassium Channels; Potassium Channels, Voltage-Gated; Xenopus laevis
PY - 2003
Y1 - 2003
N2 - 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.
Udgivelsesdato: 2003-Jun-1
AB - 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.
Udgivelsesdato: 2003-Jun-1
U2 - 10.1113/jphysiol.2003.038455
DO - 10.1113/jphysiol.2003.038455
M3 - Journal article
C2 - 12702742
VL - 549
SP - 419
EP - 427
JO - The Journal of Physiology
JF - The Journal of Physiology
SN - 0022-3751
IS - Pt 2
ER -