Kv4.3 inactivation is a complex multiexponential process, which can
occur from both closed and open states. The fast component of inactivation
is modulated by the N-terminus, but the mechanisms mediating the
other components of inactivation are controversial. We studied inactivation
of Kv4.3 expressed in Xenopus laevis oocytes, using the two-electrode
voltage-clamp technique. Inactivation during 2000 ms pulses at potentials
positive to the activation threshold was described by three exponents
(46 +/- 3, 152 +/- 13, and 930 +/- 50 ms at +50 mV, n = 7) whereas
closed-state inactivation (at potentials below threshold) was described
by two exponents (1079 +/- 119 and 3719 +/- 307 ms at -40 mV, n =
9). The fast component of open-state inactivation was dominant at
potentials positive to -20 mV. Negative to -30 mV, the intermediate
and slow components dominated inactivation. Inactivation properties
were dependent on pulse duration. Recovery from inactivation was
strongly dependent on voltage and pulse duration. We developed an
11-state Markov model of Kv4.3 gating that incorporated a direct
transition from the open-inactivated state to the closed-inactivated
state. Simulations with this model reproduced open- and closed-state
inactivation, isochronal inactivation relationships, and reopening
currents. Our data suggest that inactivation can proceed primarily
from the open state and that multiple inactivation components can
be identified.
%0 Journal Article
%1 Wang_2005_3026
%A Wang, Shimin
%A Bondarenko, Vladimir E
%A jie Qu, Yu
%A Bett, Glenna C L
%A Morales, Michael J
%A Rasmusson, Randall L
%A Strauss, Harold C
%D 2005
%J Biophys. J.
%K 16100281 Animals, Binding, Biological, Biology, Chains, Channels, Chemical, Complementary, Computational Computer DNA, Electrophysiology, Extramural, Factors, Female, Gov't, Kinetics, Markov Models, N.I.H., Non-P.H.S., Non-U.S. Oocytes, Patch-Clamp Potassium Protein Research Shal Simulation, Software, Structure,, Support, Techniques, Tertiary, Time U.S. Xenopus laevis,
%N 5
%P 3026--3041
%R 10.1529/biophysj.105.059378
%T Time- and voltage-dependent components of Kv4.3 inactivation.
%U http://dx.doi.org/10.1529/biophysj.105.059378
%V 89
%X Kv4.3 inactivation is a complex multiexponential process, which can
occur from both closed and open states. The fast component of inactivation
is modulated by the N-terminus, but the mechanisms mediating the
other components of inactivation are controversial. We studied inactivation
of Kv4.3 expressed in Xenopus laevis oocytes, using the two-electrode
voltage-clamp technique. Inactivation during 2000 ms pulses at potentials
positive to the activation threshold was described by three exponents
(46 +/- 3, 152 +/- 13, and 930 +/- 50 ms at +50 mV, n = 7) whereas
closed-state inactivation (at potentials below threshold) was described
by two exponents (1079 +/- 119 and 3719 +/- 307 ms at -40 mV, n =
9). The fast component of open-state inactivation was dominant at
potentials positive to -20 mV. Negative to -30 mV, the intermediate
and slow components dominated inactivation. Inactivation properties
were dependent on pulse duration. Recovery from inactivation was
strongly dependent on voltage and pulse duration. We developed an
11-state Markov model of Kv4.3 gating that incorporated a direct
transition from the open-inactivated state to the closed-inactivated
state. Simulations with this model reproduced open- and closed-state
inactivation, isochronal inactivation relationships, and reopening
currents. Our data suggest that inactivation can proceed primarily
from the open state and that multiple inactivation components can
be identified.
@article{Wang_2005_3026,
abstract = {Kv4.3 inactivation is a complex multiexponential process, which can
occur from both closed and open states. The fast component of inactivation
is modulated by the N-terminus, but the mechanisms mediating the
other components of inactivation are controversial. We studied inactivation
of Kv4.3 expressed in Xenopus laevis oocytes, using the two-electrode
voltage-clamp technique. Inactivation during 2000 ms pulses at potentials
positive to the activation threshold was described by three exponents
(46 +/- 3, 152 +/- 13, and 930 +/- 50 ms at +50 mV, n = 7) whereas
closed-state inactivation (at potentials below threshold) was described
by two exponents (1079 +/- 119 and 3719 +/- 307 ms at -40 mV, n =
9). The fast component of open-state inactivation was dominant at
potentials positive to -20 mV. Negative to -30 mV, the intermediate
and slow components dominated inactivation. Inactivation properties
were dependent on pulse duration. Recovery from inactivation was
strongly dependent on voltage and pulse duration. We developed an
11-state Markov model of Kv4.3 gating that incorporated a direct
transition from the open-inactivated state to the closed-inactivated
state. Simulations with this model reproduced open- and closed-state
inactivation, isochronal inactivation relationships, and reopening
currents. Our data suggest that inactivation can proceed primarily
from the open state and that multiple inactivation components can
be identified.},
added-at = {2009-06-03T11:20:58.000+0200},
author = {Wang, Shimin and Bondarenko, Vladimir E and jie Qu, Yu and Bett, Glenna C L and Morales, Michael J and Rasmusson, Randall L and Strauss, Harold C},
biburl = {https://www.bibsonomy.org/bibtex/2a8cfed52060dc3b7c1fb546ef45a22fa/hake},
description = {The whole bibliography file I use.},
doi = {10.1529/biophysj.105.059378},
file = {Wang_2005_3026.pdf:Wang_2005_3026.pdf:PDF},
interhash = {fff206ef243a780e5c7fbf1857ea1873},
intrahash = {a8cfed52060dc3b7c1fb546ef45a22fa},
journal = {Biophys. J.},
key = 293,
keywords = {16100281 Animals, Binding, Biological, Biology, Chains, Channels, Chemical, Complementary, Computational Computer DNA, Electrophysiology, Extramural, Factors, Female, Gov't, Kinetics, Markov Models, N.I.H., Non-P.H.S., Non-U.S. Oocytes, Patch-Clamp Potassium Protein Research Shal Simulation, Software, Structure,, Support, Techniques, Tertiary, Time U.S. Xenopus laevis,},
month = Nov,
number = 5,
pages = {3026--3041},
pdf = {Wang_2005_3026.pdf},
pii = {biophysj.105.059378},
pmid = {16100281},
timestamp = {2009-06-03T11:21:36.000+0200},
title = {Time- and voltage-dependent components of Kv4.3 inactivation.},
url = {http://dx.doi.org/10.1529/biophysj.105.059378},
volume = 89,
year = 2005
}