|
|
|
|
|
|
|
||
Article |
The S4 segment is an important part of the voltage sensor in voltage-gated ion channels. Cyclic nucleotide-gated channels, which are members of the superfamily of voltage-gated channels, have little inherent sensitivity to voltage despite the presence of an S4 segment. We made chimeras between a voltage-independent rat olfactory channel (rolf) and the voltage-dependent ether-à-go-go K+ channel (eag) to determine the basis of their divergent gating properties. We found that the rolf S4 segment can support a voltage-dependent mechanism of activation in eag, suggesting that rolf has a potentially functional voltage sensor that is silent during gating. In addition, we found that the S3-S4 loop of rolf increases the relative stability of the open conformation of eag, effectively converting eag into a voltage-independent channel. A single charged residue in the loop makes a significant contribution to the relative stabilization of the open state in eag. Our data suggest that cyclic nucleotide-gated channels such as rolf contain a voltage sensor which, in the physiological voltage range, is stabilized in an activated conformation that is permissive for pore opening.
Key Words: cyclic nucleotide-gated channel • voltage-gated channel • voltage dependence • potassium channel • patch clamp
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Facebook 
Reddit 
Technorati 
Twitter What's this?
This article has been cited by other articles:
|
|
 |
|
  J. R. Martinez-Francois, Y. Xu, and Z. Lu Mutations reveal voltage gating of CNGA1 channels in saturating cGMP J. Gen. Physiol., August 1, 2009; 134(2): 151 - 164. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C.-J. Jeng, Y.-T. Chen, Y.-W. Chen, and C.-Y. Tang Dominant-negative effects of human P/Q-type Ca2+ channel mutations associated with episodic ataxia type 2 Am J Physiol Cell Physiol, April 1, 2006; 290(4): C1209 - C1220. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Ma, X. J. Lou, and F. T. Horrigan Role of Charged Residues in the S1-S4 Voltage Sensor of BK Channels J. Gen. Physiol., February 27, 2006; 127(3): 309 - 328. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. P. Johnson Jr. and W. N. Zagotta The carboxyl-terminal region of cyclic nucleotide-modulated channels is a gating ring, not a permeation path PNAS, February 22, 2005; 102(8): 2742 - 2747. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. Lipscombe, T. D. Helton, and W. Xu L-Type Calcium Channels: The Low Down J Neurophysiol, November 1, 2004; 92(5): 2633 - 2641. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. P. Faillace, R. O. Bernabeu, and J. I. Korenbrot Cellular Processing of Cone Photoreceptor Cyclic GMP-gated Ion Channels: A ROLE FOR THE S4 STRUCTURAL MOTIF J. Biol. Chem., May 21, 2004; 279(21): 22643 - 22653. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 U. B. Kaupp and R. Seifert Cyclic Nucleotide-Gated Ion Channels Physiol Rev, July 1, 2002; 82(3): 769 - 824. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. R. Silverman, C.-Y. Tang, A. F. Mock, K.-B. Huh, and D. M. Papazian Mg2+ Modulates Voltage-Dependent Activation in Ether-a-Go-Go Potassium Channels by Binding between Transmembrane Segments S2 and S3 J. Gen. Physiol., November 1, 2000; 116(5): 663 - 678. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C.-Y. Tang, F. Bezanilla, and D. M. Papazian Extracellular Mg2+ Modulates Slow Gating Transitions and the Opening of Drosophila Ether-a-Go-Go Potassium Channels J. Gen. Physiol., March 1, 2000; 115(3): 319 - 338. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. M. Mannuzzu and E. Y. Isacoff Independence and Cooperativity in Rearrangements of a Potassium Channel Voltage Sensor Revealed by Single Subunit Fluorescence J. Gen. Physiol., March 1, 2000; 115(3): 257 - 268. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Madeja Extracellular Surface Charges in Voltage-Gated Ion Channels Physiology, February 1, 2000; 15(1): 15 - 19. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. A. McCormick, J. Srinivasan, K. White, T. Scheuer, and W. A. Catterall The Extracellular Domain of the beta 1 Subunit Is Both Necessary and Sufficient for beta 1-like Modulation of Sodium Channel Gating J. Biol. Chem., November 12, 1999; 274(46): 32638 - 32646. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Lehmann-Horn and K. Jurkat-Rott Voltage-Gated Ion Channels and Hereditary Disease Physiol Rev, October 1, 1999; 79(4): 1317 - 1372. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z. Lin, Y. Lin, S. Schorge, J. Q. Pan, M. Beierlein, and D. Lipscombe Alternative Splicing of a Short Cassette Exon in alpha 1B Generates Functionally Distinct N-Type Calcium Channels in Central and Peripheral Neurons J. Neurosci., July 1, 1999; 19(13): 5322 - 5331. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Schonherr, S. Hehl, H. Terlau, A. Baumann, and S. H. Heinemann Individual Subunits Contribute Independently to Slow Gating of Bovine EAG Potassium Channels J. Biol. Chem., February 26, 1999; 274(9): 5362 - 5369. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. S. Pennefather, W. Zhou, and T. E. DeCoursey Idiosyncratic Gating of HERG-like K+ Channels in Microglia J. Gen. Physiol., June 1, 1998; 111(6): 795 - 805. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Frings, N. Brull, C. Dzeja, A. Angele, V. Hagen, U. B. Kaupp, and A. Baumann Characterization of Ether-a-go-go Channels Present in Photoreceptors Reveals Similarity to IKx, a K+ Current in Rod Inner Segments J. Gen. Physiol., April 1, 1998; 111(4): 583 - 599. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. J. Smith-Maxwell, J. L. Ledwell, and R. W. Aldrich Role of the S4 in Cooperativity of Voltage-dependent Potassium Channel Activation J. Gen. Physiol., March 1, 1998; 111(3): 399 - 420. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. J. Smith-Maxwell, J. L. Ledwell, and R. W. Aldrich Uncharged S4 Residues and Cooperativity in Voltage-dependent Potassium Channel Activation J. Gen. Physiol., March 1, 1998; 111(3): 421 - 439. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Meera, M. Wallner, M. Song, and L. Toro Large conductance voltage- and calcium-dependent K+ channel, a distinct member of voltage-dependent ion channels with seven N-terminal transmembrane segments (S0-S6), an extracellular N terminus, and an intracellular (S9-S10) C terminus PNAS, December 9, 1997; 94(25): 14066 - 14071. [Abstract] [Full Text] [PDF]
|
|
|
|
