Slow Inactivation in Voltage-Gated Sodium Channels: Molecular Substrates and Contributions to Channelopathies

2001 ◽  
Vol 35 (2) ◽  
pp. 171-190 ◽  
Author(s):  
Yuriy Y Vilin ◽  
Peter C. Ruben
Keyword(s):  
Sodium Channels ◽  
Slow Inactivation ◽  
Voltage Gated ◽  
Voltage Gated Sodium Channels ◽  
Molecular Substrates

scholarly journals Voltage-sensor movements describe slow inactivation of voltage-gated sodium channels II: A periodic paralysis mutation in NaV1.4 (L689I)

2013 ◽  
Vol 141 (3) ◽  
pp. 323-334 ◽  
Author(s):  
Jonathan R. Silva ◽  
Steve A.N. Goldstein
Keyword(s):  
Sodium Channels ◽  
Time Course ◽  
Slow Component ◽  
Companion Paper ◽  
Causal Link ◽  
Periodic Paralysis ◽  
Slow Inactivation ◽  
Hyperkalemic Periodic Paralysis ◽  
Voltage Gated ◽  
Voltage Gated Sodium Channels

In skeletal muscle, slow inactivation (SI) of NaV1.4 voltage-gated sodium channels prevents spontaneous depolarization and fatigue. Inherited mutations in NaV1.4 that impair SI disrupt activity-induced regulation of channel availability and predispose patients to hyperkalemic periodic paralysis. In our companion paper in this issue (Silva and Goldstein. 2013. J. Gen. Physiol. http://dx.doi.org/10.1085/jgp.201210909), the four voltage sensors in NaV1.4 responsible for activation of channels over microseconds are shown to slowly immobilize over 1–160 s as SI develops and to regain mobility on recovery from SI. Individual sensor movements assessed via attached fluorescent probes are nonidentical in their voltage dependence, time course, and magnitude: DI and DII track SI onset, and DIII appears to reflect SI recovery. A causal link was inferred by tetrodotoxin (TTX) suppression of both SI onset and immobilization of DI and DII sensors. Here, the association of slow sensor immobilization and SI is verified by study of NaV1.4 channels with a hyperkalemic periodic paralysis mutation; L689I produces complex changes in SI, and these are found to manifest directly in altered sensor movements. L689I removes a component of SI with an intermediate time constant (∼10 s); the mutation also impedes immobilization of the DI and DII sensors over the same time domain in support of direct mechanistic linkage. A model that recapitulates SI attributes responsibility for intermediate SI to DI and DII (10 s) and a slow component to DIII (100 s), which accounts for residual SI, not impeded by L689I or TTX.

Eslicarbazepine and the enhancement of slow inactivation of voltage-gated sodium channels: A comparison with carbamazepine, oxcarbazepine and lacosamide

2015 ◽  
Vol 89 ◽  
pp. 122-135 ◽  
Author(s):  
Simon Hebeisen ◽  
Nuno Pires ◽  
Ana I. Loureiro ◽  
Maria João Bonifácio ◽  
Nuno Palma ◽  
...  
Keyword(s):  
Sodium Channels ◽  
Slow Inactivation ◽  
Voltage Gated ◽  
Voltage Gated Sodium Channels
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