|
|
|
|
|
|
|
||
J. Gen. Physiol.,
Volume 112, Number 4, October 1, 1998 457-474
From the Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut 06520
A previous study of the T442S mutant Shaker channel revealed activation-coupled subconductance
levels that apparently represent kinetic intermediates in channel activation (Zheng, J., and F.J. Sigworth. 1997. J.
Gen. Physiol. 110:101-117). We have now extended the study to heteromultimeric channels consisting of various
numbers of mutant subunits as well as channels without mutant subunits, all in the background of a chimeric
Shaker channel having increased conductance. It has been found that activation-coupled sublevels exist in all these
channel types, and are traversed in at least 80% of all deactivation time courses. In symmetric K+ solutions, the
currents in the two sublevels have a linear voltage dependence, being 23-44% and 54-70% of the fully open conductance. Sublevels in different channel types share similar voltage dependence of the mean lifetime and similar
ion selectivity properties. However, the mean lifetime of each current level depends approximately geometrically
on the number of mutant subunits in the channel, becoming shorter in channels having fewer mutant subunits.
Each mutant subunit appears to stabilize all of the conducting states by ~0.5 kcal/mol. Consistent with previous
results in the mutant channel, sublevels in channels with two or no mutant subunits also showed ion selectivities
that differ from that of the fully open level, having relatively higher K+ than Rb+ conductances. A model is presented in which Shaker channels have two coupled activation gates, one associated with the selectivity filter and a
second associated with the S6 helix bundle.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  D. G. Gagnon and F. Bezanilla A single charged voltage sensor is capable of gating the Shaker K+ channel J. Gen. Physiol., May 1, 2009; 133(5): 467 - 483. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Horn Uncooperative Voltage Sensors J. Gen. Physiol., May 1, 2009; 133(5): 463 - 466. [Full Text] [PDF]
|
|
|
|
 |
|
 H. Chen, J. Kronengold, Y. Yan, V.-R. Gazula, M. R. Brown, L. Ma, G. Ferreira, Y. Yang, A. Bhattacharjee, F. J. Sigworth, et al. The N-Terminal Domain of Slack Determines the Formation and Trafficking of Slick/Slack Heteromeric Sodium-Activated Potassium Channels J. Neurosci., April 29, 2009; 29(17): 5654 - 5665. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Z. Wang, N. C. Wong, Y. Cheng, S. J. Kehl, and D. Fedida Control of voltage-gated K+ channel permeability to NMDG+ by a residue at the outer pore J. Gen. Physiol., April 1, 2009; 133(4): 361 - 374. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Blunck, H. McGuire, H. C. Hyde, and F. Bezanilla Fluorescence detection of the movement of single KcsA subunits reveals cooperativity PNAS, December 23, 2008; 105(51): 20263 - 20268. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. S. Santos, S. M. Grigoriev, and M. Montal Molecular Template for a Voltage Sensor in a Novel K+ Channel. III. Functional Reconstitution of a Sensorless Pore Module from a Prokaryotic Kv Channel J. Gen. Physiol., December 1, 2008; 132(6): 651 - 666. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Zandany, M. Ovadia, I. Orr, and O. Yifrach Direct analysis of cooperativity in multisubunit allosteric proteins PNAS, August 19, 2008; 105(33): 11697 - 11702. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Schroeder and U.-P. Hansen Tl+-induced {micro}s Gating of Current Indicates Instability of the MaxiK Selectivity Filter as Caused by Ion/Pore Interaction J. Gen. Physiol., March 31, 2008; 131(4): 365 - 378. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bruening-Wright, W.-S. Lee, J. P. Adelman, and J. Maylie Evidence for a Deep Pore Activation Gate in Small Conductance Ca2+-activated K+ Channels J. Gen. Physiol., November 26, 2007; 130(6): 601 - 610. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Schroeder and U.-P. Hansen Saturation and Microsecond Gating of Current Indicate Depletion-induced Instability of the MaxiK Selectivity Filter J. Gen. Physiol., July 1, 2007; 130(1): 83 - 97. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Cheng, F. Yang, C. L. Takanishi, and J. Zheng Thermosensitive TRPV Channel Subunits Coassemble into Heteromeric Channels with Intermediate Conductance and Gating Properties J. Gen. Physiol., March 26, 2007; 129(3): 191 - 207. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Blunck, J. F. Cordero-Morales, L. G. Cuello, E. Perozo, and F. Bezanilla Detection of the Opening of the Bundle Crossing in KcsA with Fluorescence Lifetime Spectroscopy Reveals the Existence of Two Gates for Ion Conduction J. Gen. Physiol., November 1, 2006; 128(5): 569 - 581. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. Li and R. W. Aldrich State-dependent Block of BK Channels by Synthesized Shaker Ball Peptides J. Gen. Physiol., October 1, 2006; 128(4): 423 - 441. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. G. Trapani, P. Andalib, J. F. Consiglio, and S. J. Korn Control of Single Channel Conductance in the Outer Vestibule of the Kv2.1 Potassium Channel J. Gen. Physiol., July 31, 2006; 128(2): 231 - 246. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Li, J. Jiang, and L. Yue Functional Characterization of Homo- and Heteromeric Channel Kinases TRPM6 and TRPM7 J. Gen. Physiol., April 24, 2006; 127(5): 525 - 537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Piskorowski and R. W. Aldrich Relationship between Pore Occupancy and Gating in BK Potassium Channels J. Gen. Physiol., April 24, 2006; 127(5): 557 - 576. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. del Camino, M. Kanevsky, and G. Yellen Status of the Intracellular Gate in the Activated-not-open State of Shaker K+ Channels J. Gen. Physiol., October 31, 2005; 126(5): 419 - 428. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Xie, X.-g. Zhen, and J. Yang Localization of the Activation Gate of a Voltage-gated Ca2+ Channel J. Gen. Physiol., August 29, 2005; 126(3): 205 - 212. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Bezanilla The Origin of Subconductance Levels in Voltage-gated K+ Channels J. Gen. Physiol., July 25, 2005; 126(2): 83 - 86. [Full Text] [PDF]
|
|
|
|
|
|
M. L. Chapman and A. M.J. VanDongen K Channel Subconductance Levels Result from Heteromeric Pore Conformations J. Gen. Physiol., July 25, 2005; 126(2): 87 - 103. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Pathak, L. Kurtz, F. Tombola, and E. Isacoff The Cooperative Voltage Sensor Motion that Gates a Potassium Channel J. Gen. Physiol., December 28, 2004; 125(1): 57 - 69. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Isaev, K. Solt, O. Gurtovaya, J. P. Reeves, and R. Shirokov Modulation of the Voltage Sensor of L-type Ca2+ Channels by Intracellular Ca2+ J. Gen. Physiol., April 26, 2004; 123(5): 555 - 571. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. S. Rothberg Allosteric Modulation of Ion Channels: The Case of Maxi-K Sci. Signal., April 6, 2004; 2004(227): pe16 - pe16. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. F. Consiglio and S. J. Korn Influence of Permeant Ions on Voltage Sensor Function in the Kv2.1 Potassium Channel J. Gen. Physiol., March 29, 2004; 123(4): 387 - 400. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. J. VanDongen K channel gating by an affinity-switching selectivity filter PNAS, March 2, 2004; 101(9): 3248 - 3252. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Sukhareva, D. H. Hackos, and K. J. Swartz Constitutive Activation of the Shaker Kv Channel J. Gen. Physiol., October 27, 2003; 122(5): 541 - 556. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Talavera, A. Janssens, N. Klugbauer, G. Droogmans, and B. Nilius Pore Structure Influences Gating Properties of the T-type Ca2+ Channel {alpha}1G J. Gen. Physiol., May 27, 2003; 121(6): 529 - 540. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Schorge and D. Colquhoun Studies of NMDA Receptor Function and Stoichiometry with Truncated and Tandem Subunits J. Neurosci., February 15, 2003; 23(4): 1151 - 1158. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Zhang and C. M. Canessa Single Channel Properties of Rat Acid-sensitive Ion Channel-1{alpha}, -2a, and -3 Expressed in Xenopus Oocytes J. Gen. Physiol., September 30, 2002; 120(4): 553 - 566. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 V. Macri, C. Proenza, E. Agranovich, D. Angoli, and E. A. Accili Separable Gating Mechanisms in a Mammalian Pacemaker Channel J. Biol. Chem., September 20, 2002; 277(39): 35939 - 35946. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Niu and K. L. Magleby Stepwise contribution of each subunit to the cooperative activation of BK channels by Ca2+ PNAS, August 20, 2002; 99(17): 11441 - 11446. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bruening-Wright, M. A. Schumacher, J. P. Adelman, and J. Maylie Localization of the Activation Gate for Small Conductance Ca2+-activated K+ Channels J. Neurosci., August 1, 2002; 22(15): 6499 - 6506. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Guatimosim, E. A. Sobie, J. dos Santos Cruz, L. A. Martin, and W. J. Lederer Molecular identification of a TTX-sensitive Ca2+ current Am J Physiol Cell Physiol, May 1, 2001; 280(5): C1327 - C1339. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. He, M. Ruiz, and J. W. Karpen Constraining the subunit order of rod cyclic nucleotide-gated channels reveals a diagonal arrangement of like subunits PNAS, January 18, 2000; 97(2): 895 - 900. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. P. Babenko, G. C. Gonzalez, and J. Bryan Hetero-concatemeric KIR6.X4/SUR14 Channels Display Distinct Conductivities but Uniform ATP Inhibition J. Biol. Chem., October 6, 2000; 275(41): 31563 - 31566. [Abstract] [Full Text] [PDF]
|
|
|
|
