کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1960050 1057950 2005 16 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Time- and Voltage-Dependent Components of Kv4.3 Inactivation
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Time- and Voltage-Dependent Components of Kv4.3 Inactivation
چکیده انگلیسی

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.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: - Volume 89, Issue 5, November 2005, Pages 3026–3041
نویسندگان
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