scholarly journals Direct Interaction of a Brain Voltage-Gated K+Channel with Syntaxin 1A: Functional Impact on Channel Gating

2001 ◽  
Vol 21 (6) ◽  
pp. 1964-1974 ◽  
Author(s):  
Oded Fili ◽  
Itzhak Michaelevski ◽  
Yaniv Bledi ◽  
Dodo Chikvashvili ◽  
Dafna Singer-Lahat ◽  
...  
Keyword(s):  
Channel Gating ◽  
Direct Interaction ◽  
K Channel ◽  
Syntaxin 1A ◽  
Functional Impact ◽  
Voltage Gated

Molecular site for nucleotide binding on an ATP-sensitive renal K+ channel (ROMK2)

1996 ◽  
Vol 271 (2) ◽  
pp. F275-F285 ◽  
Author(s):  
C. M. McNicholas ◽  
Y. Yang ◽  
G. Giebisch ◽  
S. C. Hebert
Keyword(s):  
Channel Gating ◽  
Direct Interaction ◽  
K Channel ◽  
Amino Terminus ◽  
Atp Binding Site ◽  
Gating Mechanism ◽  
Alternatively Spliced ◽  
Carboxy Terminal ◽  
Apical Membranes

ATP-sensitive, inwardly rectifying K+ channels are present in apical membranes of the distal nephron and play a major role in K+ recycling and secretion. The cloned renal K+ channel, ROMK1, is a candidate for the renal epithelial K+ channel, since it shares many functional characteristics with the native channel. Additionally, ROMK1 contains a putative carboxy-terminal ATP-binding site. Although ROMK1 channel activity could be reactivated by cytosolic Mg-ATP after rundown, the role of nucleotides in channel gating was less certain. We now show that an alternatively spliced transcript of the ROMK channel gene, ROMK2, which encodes a K+ channel with a truncated amino terminus, expresses an ATP-regulated and ATP-sensitive K+ channel (IKATP). Differences in the amino terminus of ROMK isoforms alters the sensitivity of the channel-gating mechanism to ATP. To test whether ATP sensitivity of renal IKATP is mediated by direct interaction of nucleotide, point mutation of specific residues within the ROMK2 phosphate loop (P-loop) were investigated. These either enhanced or attenuated the sensitivity to both activation and inhibition by Mg-ATP, thus demonstrating a direct interaction of nucleotide with the channel-forming polypeptide.

Voltage clamp fluorimetry studies of mammalian voltage-gated K+ channel gating

2007 ◽  
Vol 35 (5) ◽  
pp. 1080-1082 ◽  
Author(s):  
T.W. Claydon ◽  
D. Fedida
Keyword(s):  
Ion Channel ◽  
Potassium Channel ◽  
Real Time ◽  
Voltage Clamp ◽  
Conformational Changes ◽  
Channel Gating ◽  
K Channel ◽  
Voltage Gated ◽  
Kv Channels ◽  
Health And Disease

VCF (voltage clamp fluorimetry) provides a powerful technique to observe real-time conformational changes that are associated with ion channel gating. The present review highlights the insights such experiments have provided in understanding Kv (voltage-gated potassium) channel gating, with particular emphasis on the study of mammalian Kv1 channels. Further applications of VCF that would contribute to our understanding of the modulation of Kv channels in health and disease are also discussed.

The 1997 Stevenson Award Lecture. Cardiac K+channel gating: cloned delayed rectifier mechanisms and drug modulation

1998 ◽  
Vol 76 (2) ◽  
pp. 77-89 ◽  
Author(s):  
David Fedida ◽  
Fred SP Chen ◽  
Xue Zhang
Keyword(s):  
Channel Gating ◽  
State Dependence ◽  
Structural Features ◽  
K Channel ◽  
Delayed Rectifier ◽  
Specific Reference ◽  
Channel Blockers ◽  
Antiarrhythmic Agents ◽  
Gating Currents ◽  
Voltage Gated

K+ channels are ubiquitous membrane proteins, which have a central role in the control of cell excitability. In the heart, voltage-gated delayed rectifier K+ channels, like Kv1.5, determine repolarization and the cardiac action potential plateau duration. Here we review the broader properties of cloned voltage-gated K+ channels with specific reference to the hKv1.5 channel in heart. We discuss the basic structural components of K+ channels such as the pore, voltage sensor, and fast inactivation, all of which have been extensively studied. Slow, or C-type, inactivation and the structural features that control pore opening are less well understood, although recent studies have given new insight into these problems. Information about channel transitions that occur prior to opening is provided by gating currents, which reflect charge-carrying transitions between kinetic closed states. By studying modulation of the gating properties of K+ channels by cations and with drugs, we can make a more complete interpretation of the state dependence of drug and ion interactions with the channel. In this way we can uncover the detailed mechanisms of action of K+ channel blockers such as tetraethylammonium ions and 4-aminopyridine, and antiarrhythmic agents such as nifedipine and quinidine.Key words: potassium channel, Kv1.5, channel gating, inactivation, pore region, gating currents.

scholarly journals Modulation of a Brain Voltage-gated K+Channel by Syntaxin 1A Requires the Physical Interaction of Gβγ with the Channel

2002 ◽  
Vol 277 (38) ◽  
pp. 34909-34917 ◽  
Author(s):  
Izhak Michaelevski ◽  
Dodo Chikvashvili ◽  
Sharon Tsuk ◽  
Oded Fili ◽  
Martin J. Lohse ◽  
...  
Keyword(s):  
K Channel ◽  
Physical Interaction ◽  
Syntaxin 1A ◽  
Voltage Gated

scholarly journals Direct Interaction of Otoferlin with Syntaxin 1A, SNAP-25, and the L-type Voltage-gated Calcium Channel CaV1.3

2008 ◽  
Vol 284 (3) ◽  
pp. 1364-1372 ◽  
Author(s):  
Neeliyath A. Ramakrishnan ◽  
Marian J. Drescher ◽  
Dennis G. Drescher
Keyword(s):  
Calcium Channel ◽  
Direct Interaction ◽  
Syntaxin 1A ◽  
Voltage Gated ◽  
Voltage Gated Calcium Channel

scholarly journals K+ channel gating: C-type inactivation is enhanced by calcium or lanthanum outside

2014 ◽  
Vol 144 (3) ◽  
pp. 221-230 ◽  
Author(s):  
Clay M. Armstrong ◽  
Toshinori Hoshi
Keyword(s):  
Channel Gating ◽  
Selectivity Filter ◽  
K Channel ◽  
Slow Process ◽  
K Channels ◽  
Inward Current ◽  
Voltage Gated ◽  
Positive Shift ◽  
High Affinity ◽  
Opening And Closing

Many voltage-gated K+ channels exhibit C-type inactivation. This typically slow process has been hypothesized to result from dilation of the outer-most ring of the carbonyls in the selectivity filter, destroying this ring’s ability to bind K+ with high affinity. We report here strong enhancement of C-type inactivation upon extracellular addition of 10–40 mM Ca2+ or 5–50 µM La3+. These multivalent cations mildly increase the rate of C-type inactivation during depolarization and markedly promote inactivation and/or suppress recovery when membrane voltage (Vm) is at resting levels (−80 to −100 mV). At −80 mV with 40 mM Ca2+ and 0 mM K+ externally, ShBΔN channels with the mutation T449A inactivate almost completely within 2 min or less with no pulsing. This behavior is observed only in those mutants that show C-type inactivation on depolarization and is distinct from the effects of Ca2+ and La3+ on activation (opening and closing of the Vm-controlled gate), i.e., slower activation of K+ channels and a positive shift of the mid-voltage of activation. The Ca2+/La3+ effects on C-type inactivation are antagonized by extracellular K+ in the low millimolar range. This, together with the known ability of Ca2+ and La3+ to block inward current through K+ channels at negative voltage, strongly suggests that Ca2+/La3+ acts at the outer mouth of the selectivity filter. We propose that at −80 mV, Ca2+ or La3+ ions compete effectively with K+ at the channel’s outer mouth and prevent K+ from stabilizing the filter’s outer carbonyl ring.

Structural Influence of Hanatoxin Binding on the Carboxyl Terminus of S3 Segment in Voltage-Gated K + -Channel Kv2.1

2002 ◽  
Vol 8 (2) ◽  
pp. 79-85 ◽  
Author(s):  
P. T. Huang ◽  
T. Y. Chen ◽  
L. J. Tseng ◽  
K. L. Lou ◽  
H. H. Liou ◽  
...  
Keyword(s):  
Carboxyl Terminus ◽  
K Channel ◽  
Voltage Gated ◽  
S3 Segment ◽  
Structural Influence

TNF-α inhibits the CD3-mediated upregulation of voltage-gated K+ channel (Kv1.3) in human T cells

2010 ◽  
Vol 391 (1) ◽  
pp. 909-914 ◽  
Author(s):  
Bo Pang ◽  
Haifeng Zheng ◽  
Dong Hoon Shin ◽  
Kyeong Cheon Jung ◽  
Jae Hong Ko ◽  
...  
Keyword(s):  
T Cells ◽  
K Channel ◽  
Voltage Gated ◽  
Human T Cells ◽  
Tnf Α

scholarly journals The voltage-gated K+ channel Kv1.3 modulates platelet motility and α2β1 integrin-dependent adhesion to collagen

Platelets ◽  
2021 ◽  
pp. 1-11
Author(s):  
Joy R Wright ◽  
Sarah Jones ◽  
Sasikumar Parvathy ◽  
Leonard K Kaczmarek ◽  
Ian Forsythe ◽  
...  
Keyword(s):  
K Channel ◽  
Voltage Gated ◽  
Α2β1 Integrin
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