scholarly journals Voltage-dependent and calcium-dependent inactivation of calcium channel current in identified snail neurones.

1989 ◽  
Vol 412 (1) ◽  
pp. 197-220 ◽  
Author(s):  
M J Gutnick ◽  
H D Lux ◽  
D Swandulla ◽  
H Zucker
Keyword(s):  
Calcium Channel ◽  
Calcium Dependent ◽  
Channel Current ◽  
Dependent Inactivation ◽  
Snail Neurones ◽  
Voltage Dependent

scholarly journals Disruption of the IS6-AID Linker Affects Voltage-gated Calcium Channel Inactivation and Facilitation

2009 ◽  
Vol 133 (3) ◽  
pp. 327-343 ◽  
Author(s):  
Felix Findeisen ◽  
Daniel L. Minor
Keyword(s):  
Calcium Channel ◽  
Common Mechanism ◽  
Interaction Domain ◽  
Voltage Gated ◽  
Calcium Dependent ◽  
Calcium Channel Inactivation ◽  
Dependent Inactivation ◽  
Voltage Dependent ◽  
Rigid Connection ◽  
Voltage Gated Calcium Channel

Two processes dominate voltage-gated calcium channel (CaV) inactivation: voltage-dependent inactivation (VDI) and calcium-dependent inactivation (CDI). The CaVβ/CaVα1-I-II loop and Ca2+/calmodulin (CaM)/CaVα1–C-terminal tail complexes have been shown to modulate each, respectively. Nevertheless, how each complex couples to the pore and whether each affects inactivation independently have remained unresolved. Here, we demonstrate that the IS6–α-interaction domain (AID) linker provides a rigid connection between the pore and CaVβ/I-II loop complex by showing that IS6-AID linker polyglycine mutations accelerate CaV1.2 (L-type) and CaV2.1 (P/Q-type) VDI. Remarkably, mutations that either break the rigid IS6-AID linker connection or disrupt CaVβ/I-II association sharply decelerate CDI and reduce a second Ca2+/CaM/CaVα1–C-terminal–mediated process known as calcium-dependent facilitation. Collectively, the data strongly suggest that components traditionally associated solely with VDI, CaVβ and the IS6-AID linker, are essential for calcium-dependent modulation, and that both CaVβ-dependent and CaM-dependent components couple to the pore by a common mechanism requiring CaVβ and an intact IS6-AID linker.

Altered frequency-dependent inactivation and steady-state inactivation of polyglutamine-expanded α1A in SCA6

2007 ◽  
Vol 292 (3) ◽  
pp. C1078-C1086 ◽  
Author(s):  
Haiyan Chen ◽  
Erika S. Piedras-Rentería
Keyword(s):  
Steady State ◽  
Late Onset ◽  
Spinocerebellar Ataxia Type ◽  
Gain Of Function ◽  
Calcium Dependent ◽  
Spinocerebellar Ataxia Type 6 ◽  
Dependent Inactivation ◽  
Voltage Dependent ◽  
Steady State Inactivation ◽  
Activity Dependent

Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease of the cerebellum and inferior olives characterized by a late-onset cerebellar ataxia and selective loss of Purkinje neurons ( 15 , 16 ). SCA6 arises from an expansion of the polyglutamine tract located in exon 47 of the α1A (P/Q-type calcium channel) gene from a nonpathogenic size of 4 to 18 glutamines (CAG4–18) to CAG19–33 in SCA6. The molecular basis of SCA6 is poorly understood. To date, the biophysical properties studied in heterologous systems support both a gain and a loss of channel function in SCA6. We studied the behavior of the human α1A isoform, previously found to elicit a gain of function in disease ( 41 ), focusing on properties in which the COOH terminus of the channel is critical for function: we analyzed the current properties in the presence of β4- and β2a-subunits (both known to interact with the α1A COOH terminus), current kinetics of activation and inactivation, calcium-dependent inactivation and facilitation, voltage-dependent inactivation, frequency dependence, and steady-state activation and inactivation properties. We found that SCA6 channels have decreased activity-dependent inactivation and a depolarizing shift (+6 mV) in steady-state inactivation properties consistent with a gain of function.

scholarly journals A Selectivity Filter Gate Controls Voltage-Gated Calcium Channel Calcium-Dependent Inactivation

Neuron ◽  
2019 ◽  
Vol 101 (6) ◽  
pp. 1134-1149.e3 ◽  
Author(s):  
Fayal Abderemane-Ali ◽  
Felix Findeisen ◽  
Nathan D. Rossen ◽  
Daniel L. Minor
Keyword(s):  
Calcium Channel ◽  
Selectivity Filter ◽  
Voltage Gated ◽  
Calcium Dependent ◽  
Dependent Inactivation ◽  
Voltage Gated Calcium Channel

Synexin: Molecular Mechanism of Calcium-Dependent Membrane Fusion and Voltage-Dependent Calcium-Channel Activity.

1991 ◽  
Vol 635 (1 Calcium Entry) ◽  
pp. 328-351 ◽  
Author(s):  
HARVEY B. POLLARD ◽  
EDUARDO ROJAS ◽  
RICHARD W. PASTOR ◽  
EDUARDO M. ROJAS ◽  
H. ROBERT GUY ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Membrane Fusion ◽  
Molecular Mechanism ◽  
Channel Activity ◽  
Calcium Dependent ◽  
Voltage Dependent Calcium Channel ◽  
Voltage Dependent

scholarly journals The structural biology of voltage-gated calcium channel function and regulation

2006 ◽  
Vol 34 (5) ◽  
pp. 887-893 ◽  
Author(s):  
F. Van Petegem ◽  
D.L. Minor
Keyword(s):  
Neurotransmitter Release ◽  
Action Potentials ◽  
Molecular Switches ◽  
Voltage Gated ◽  
Calcium Dependent ◽  
Voltage Gated Calcium Channels ◽  
Dependent Inactivation ◽  
Voltage Dependent ◽  
Soluble Calcium ◽  
Molecular Framework

Voltage-gated calcium channels (CaVs) are large (∼0.5 MDa), multisubunit, macromolecular machines that control calcium entry into cells in response to membrane potential changes. These molecular switches play pivotal roles in cardiac action potentials, neurotransmitter release, muscle contraction, calcium-dependent gene transcription and synaptic transmission. CaVs possess self-regulatory mechanisms that permit them to change their behaviour in response to activity, including voltage-dependent inactivation, calcium-dependent inactivation and calcium-dependent facilitation. These processes arise from the concerted action of different channel domains with CaV β-subunits and the soluble calcium sensor calmodulin. Until recently, nothing was known about the CaV structure at high resolution. Recent crystallographic work has revealed the first glimpses at the CaV molecular framework and set a new direction towards a detailed mechanistic understanding of CaV function.

scholarly journals Inactivation of calcium channel current in the calf cardiac Purkinje fiber. Evidence for voltage- and calcium-mediated mechanisms.

1984 ◽  
Vol 84 (5) ◽  
pp. 705-726 ◽  
Author(s):  
R S Kass ◽  
M C Sanguinetti
Keyword(s):  
Charge Carrier ◽  
Divalent Cations ◽  
Purkinje Fiber ◽  
Ca Channel ◽  
Channel Current ◽  
Zero Current ◽  
Dependent Inactivation ◽  
Voltage Dependent ◽  
Ca Channel Current ◽  
Dependent Mechanism

We have studied the influence of divalent cations on Ca channel current in the calf cardiac Purkinje fiber to determine whether this current inactivates by voltage- or Ca-mediated mechanisms, or by a combination of the two. We measured the reversal (or zero current) potential of the current when Ba, Sr, or Ca were the permeant divalent cations and determined that depletion of charge carrier does not account for time-dependent relaxation of Ca channel current in these preparations. Inactivation of Ca channel current persists when Ba or Sr replaces Ca as the permeant divalent cation, but the voltage dependence of the rate of inactivation is markedly changed. This effect cannot be explained by changes in external surface charge. Instead, we interpret the results as evidence that inactivation is both voltage and Ca dependent. Inactivation of Sr or Ba currents reflects a voltage-dependent process. When Ca is the divalent charge carrier, an additional effect is observed: the rate of inactivation is increased as Ca enters during depolarizing pulses, perhaps because of an additional Ca-dependent mechanism.

scholarly journals Single-Channel Mechanism of Modulation of Calcium-Dependent Inactivation of the Voltage-Gated Calcium Channel Cav1.3 by its C-Terminus

2013 ◽  
Vol 104 (2) ◽  
pp. 459a
Author(s):  
Elena Novikova ◽  
Elza Kuzmenkina ◽  
Wanchana Jangsangthong ◽  
Jan Matthes ◽  
Alexandra Koschak ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Single Channel ◽  
Voltage Gated ◽  
Calcium Dependent ◽  
C Terminus ◽  
Dependent Inactivation ◽  
Voltage Gated Calcium Channel
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