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Data
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Hysteresis in voltage gating of HCN channels (Elinder et al 2006, Mannikko et al 2005)
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We found that HCN2 and HCN4 channels
expressed in oocytes from the frog Xenopus laevis do not display the
activation kinetic changes that we (previously) observed in spHCN and
HCN1. However, HCN2 and HCN4 channels display changes in their tail
currents, suggesting that these channels also undergo mode shifts and
that the conformational changes underlying the mode shifts are due to
conserved aspects of HCN channels. With computer modelling, we show
that in channels with relatively slow opening kinetics and fast
mode-shift transitions, such as HCN2 and HCN4 channels, the mode shift
effects are not readily observable, except in the tail
kinetics. Computer simulations of sino-atrial node action potentials
suggest that the HCN2 channel, together with the HCN1 channel, are
important regulators of the heart firing frequency and that the mode
shift is an important property to prevent arrhythmic firing. We
conclude that although all HCN channels appear to undergo mode shifts
– and thus may serve to prevent arrhythmic firing
– it is mainly observable in ionic currents
from HCN channels with faster kinetics. See papers for more and details.
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Elinder F, Männikkö R, Pandey S, Larsson HP (2006) Show
Other
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Männikkö R, Pandey S, Larsson HP, Elinder F (2005) Show
Other
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Elinder, Fredrik [fredrik.elinder at ibk.liu.se] Show
Other
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