scholarly journals Sodium channel slow inactivation interferes with open channel block

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Martin Hampl ◽  
Esther Eberhardt ◽  
Andrias O. O’Reilly ◽  
Angelika Lampert
Keyword(s):  
Sodium Channel ◽  
Open Channel ◽  
Slow Inactivation ◽  
Channel Block ◽  
Open Channel Block

scholarly journals Open-Channel Block by the Cytoplasmic Tail of Sodium Channel β4 as a Mechanism for Resurgent Sodium Current

Neuron ◽  
2005 ◽  
Vol 45 (2) ◽  
pp. 233-244 ◽  
Author(s):  
Tina M. Grieco ◽  
Jyoti D. Malhotra ◽  
Chunling Chen ◽  
Lori L. Isom ◽  
Indira M. Raman
Keyword(s):  
Sodium Channel ◽  
Open Channel ◽  
Sodium Current ◽  
Cytoplasmic Tail ◽  
Channel Block ◽  
Open Channel Block ◽  
Resurgent Sodium Current

scholarly journals Subunit Dependence of Na Channel Slow Inactivation and Open Channel Block in Cerebellar Neurons

2007 ◽  
Vol 92 (6) ◽  
pp. 1938-1951 ◽  
Author(s):  
Teresa K. Aman ◽  
Indira M. Raman
Keyword(s):  
Open Channel ◽  
Na Channel ◽  
Slow Inactivation ◽  
Channel Block ◽  
Open Channel Block ◽  
Cerebellar Neurons

Open-channel-block induced by the neurotransmitter glycine in homomeric alpha1-GlyR and heteromeric alpha1/beta1- GlyR

2008 ◽  
Vol 35 (S 01) ◽  
Author(s):  
Y.P Song ◽  
F Schlesinger ◽  
S Petri ◽  
R Dengler ◽  
K Krampfl
Keyword(s):  
Open Channel ◽  
Channel Block ◽  
Open Channel Block

scholarly journals Interactions among DIV voltage-sensor movement, fast inactivation, and resurgent Na current induced by the NaVβ4 open-channel blocking peptide

2013 ◽  
Vol 142 (3) ◽  
pp. 191-206 ◽  
Author(s):  
Amanda H. Lewis ◽  
Indira M. Raman
Keyword(s):  
Open Channel ◽  
Voltage Sensor ◽  
Channel Block ◽  
Na Channels ◽  
Fast Inactivation ◽  
Na Current ◽  
Open Channel Block ◽  
Channel Blocking ◽  
Open States ◽  
Resurgent Currents

Resurgent Na current flows as voltage-gated Na channels recover through open states from block by an endogenous open-channel blocking protein, such as the NaVβ4 subunit. The open-channel blocker and fast-inactivation gate apparently compete directly, as slowing the onset of fast inactivation increases resurgent currents by favoring binding of the blocker. Here, we tested whether open-channel block is also sensitive to deployment of the DIV voltage sensor, which facilitates fast inactivation. We expressed NaV1.4 channels in HEK293t cells and assessed block by a free peptide replicating the cytoplasmic tail of NaVβ4 (the “β4 peptide”). Macroscopic fast inactivation was disrupted by mutations of DIS6 (L443C/A444W; “CW” channels), which reduce fast-inactivation gate binding, and/or by the site-3 toxin ATX-II, which interferes with DIV movement. In wild-type channels, the β4 peptide competed poorly with fast inactivation, but block was enhanced by ATX. With the CW mutation, large peptide-induced resurgent currents were present even without ATX, consistent with increased open-channel block upon depolarization and slower deactivation after blocker unbinding upon repolarization. The addition of ATX greatly increased transient current amplitudes and further enlarged resurgent currents, suggesting that pore access by the blocker is actually decreased by full deployment of the DIV voltage sensor. ATX accelerated recovery from block at hyperpolarized potentials, however, suggesting that the peptide unbinds more readily when DIV voltage-sensor deployment is disrupted. These results are consistent with two open states in Na channels, dependent on the DIV voltage-sensor position, which differ in affinity for the blocking protein.

GABAA receptor activation and open-channel block by volatile anaesthetics: a new principle of receptor modulation?

2002 ◽  
Vol 451 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Rainer Haseneder ◽  
Gerhard Rammes ◽  
Walter Zieglgänsberger ◽  
Eberhard Kochs ◽  
Gerhard Hapfelmeier
Keyword(s):  
Gabaa Receptor ◽  
Open Channel ◽  
Receptor Activation ◽  
Channel Block ◽  
Volatile Anaesthetics ◽  
Open Channel Block ◽  
Receptor Modulation

scholarly journals Membrane Lipid Modulations Remove Divalent Open Channel Block from TRP-Like and NMDA Channels

2009 ◽  
Vol 29 (8) ◽  
pp. 2371-2383 ◽  
Author(s):  
M. Parnas ◽  
B. Katz ◽  
S. Lev ◽  
V. Tzarfaty ◽  
D. Dadon ◽  
...  
Keyword(s):  
Open Channel ◽  
Membrane Lipid ◽  
Channel Block ◽  
Open Channel Block ◽  
Nmda Channels

Open channel block and open channel destabilization: contrasting effects of phenol, TEA+ and local anaesthetics on Kv1.1 K+ channels

1998 ◽  
Vol 100-101 ◽  
pp. 277-285 ◽  
Author(s):  
A.A. Elliott ◽  
J.A. Harrold ◽  
J.P. Newman ◽  
J.R. Elliott
Keyword(s):  
Open Channel ◽  
Local Anaesthetics ◽  
Channel Block ◽  
Open Channel Block ◽  
K Channels

Open channel block of human heart hKv1.5 by the beta-subunit hKv beta 1.2

1997 ◽  
Vol 272 (6) ◽  
pp. H2932-H2941 ◽  
Author(s):  
M. De Biasi ◽  
Z. Wang ◽  
E. Accili ◽  
B. Wible ◽  
D. Fedida
Keyword(s):  
Human Heart ◽  
Open Channel ◽  
Beta Subunit ◽  
Beta Subunits ◽  
Channel Block ◽  
Open Channel Block ◽  
Pharmacological Characterization ◽  
Kinetics Of ◽  
K Currents

Voltage-gated K+ currents in human heart are likely to derive from multisubunit complexes of pore-forming alpha-subunits with one or more auxiliary beta-subunits. We recently cloned a novel beta-subunit from human atrium, hKv beta 1.2 (K. Majumder, M. De Biasi, Z. Wang, and B. A. Wible. FEBS Lett. 361: 13-16, 1995), and showed that it interacts with channels in the Kv1 family. Here we characterize the interaction of hKv beta 1.2 with hKv1.5 in terms of a two-closed-state and one-open-state open channel block model. After coexpression in Xenopus oocytes, hKv1.5 currents were reduced in the presence of hKv beta 1.2, and at positive potentials an inactivation process was introduced. Deactivation kinetics of hKv1.5 were slowed, and there was an increased steepness with a -14-mV hyperpolarizing shift in the midpoint of steady-state activation. The model was able to predict all the above features of the interaction of hKv1.5 and hKv beta 1.2 as a result of rapid open channel block of activated channels. Understanding the mechanism of hKv beta 1.2 action on heart K+ channels will further aid the development of the functional and pharmacological characterization of native cardiac K+ currents.

Molecular Basis for a High-Potency Open-Channel Block of Kv1.5 Channel by the Endocannabinoid Anandamide

2010 ◽  
Vol 77 (5) ◽  
pp. 751-758 ◽  
Author(s):  
Eloy G. Moreno-Galindo ◽  
Gabriel F. Barrio-Echavarría ◽  
José C. Vásquez ◽  
Niels Decher ◽  
Frank B. Sachse ◽  
...  
Keyword(s):  
Molecular Basis ◽  
Open Channel ◽  
Channel Block ◽  
High Potency ◽  
Open Channel Block
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