| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
J. Biol. Chem., Vol. 276, Issue 27, 24449-24452, July 6, 2001
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
From the Departments of Pediatrics and Cellular and Molecular
Physiology, Boyer Center for Molecular Medicine, Yale University School
of Medicine, New Haven, Connecticut 06536
KCNK subunits have two pore-forming P
domains and four predicted transmembrane segments. To assess the number
of subunits in each pore, we studied external proton block of Kcnk3, a
subunit prominent in rodent heart and brain. Consistent with a
pore-blocking mechanism, inhibition was dependent on voltage, potassium
concentration, and a histidine in the first P domain (P1H). Thus, at pH
6.8 with 20 mM potassium half the current passed by
P1H channels was blocked (apparently via two sites ~10% into the
electrical field) whereas channels with an asparagine substitution
(P1N) were fully active. Furthermore, pore blockade by barium was
sensitive to pH in P1H but not P1N channels. Although linking two Kcnk3
subunits in tandem to produce P1H-P1H and P1N-P1N channels bearing four
P domains did not alter these attributes, the mixed tandems P1H-P1N and P1N-P1H were half-blocked at pH ~6.4, apparently via a single site.
This implicates a dimeric structure for Kcnk3 channels with two (and
only two) P1 domains in each pore and argues that P2 domains also
contribute to pore formation.
To whom correspondence should be addressed: 295 Congress Ave., New
Haven, CT 06536. Tel.: 203-737-2214; Fax: 203-737-2290; E-mail:
steve.goldstein@yale.edu.
This article has been cited by other articles:
|
|
 |
|
  C. Putzke, K. Wemhoner, F. B. Sachse, S. Rinne, G. Schlichthorl, X. T. Li, L. Jae, I. Eckhardt, E. Wischmeyer, H. Wulf, et al. The acid-sensitive potassium channel TASK-1 in rat cardiac muscle Cardiovasc Res, July 1, 2007; 75(1): 59 - 68. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. I. Niemeyer, F. D. Gonzalez-Nilo, L. Zuniga, W. Gonzalez, L. P. Cid, and F. V. Sepulveda Neutralization of a single arginine residue gates open a two-pore domain, alkali-activated K+ channel PNAS, January 9, 2007; 104(2): 666 - 671. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. W. Abbott, M. H. Butler, and S. A. N. Goldstein Phosphorylation and protonation of neighboring MiRP2 sites: function and pathophysiology of MiRP2-Kv3.4 potassium channels in periodic paralysis FASEB J, February 1, 2006; 20(2): 293 - 301. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. J. Morton, A. Abohamed, A. Sivaprasadarao, and M. Hunter pH sensing in the two-pore domain K+ channel, TASK2 PNAS, November 1, 2005; 102(44): 16102 - 16106. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. D O'Connell, M. J Morton, A. Sivaprasadarao, and M. Hunter Selectivity and interactions of Ba2+ and Cs+ with wild-type and mutant TASK1 K+ channels expressed in Xenopus oocytes J. Physiol., February 1, 2005; 562(3): 687 - 696. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. E Clarke, E. L Veale, P. J Green, H. J Meadows, and A. Mathie Selective block of the human 2-P domain potassium channel, TASK-3, and the native leak potassium current, IKSO, by zinc J. Physiol., October 1, 2004; 560(1): 51 - 62. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. P. Johnson, I. M. O'Kelly, and I. M. Fearon System-specific O2 sensitivity of the tandem pore domain K+ channel TASK-1 Am J Physiol Cell Physiol, February 1, 2004; 286(2): C391 - C397. [Abstract] [Full Text]
|
|
|
|
|
|
D. Kang, J. Han, E. M. Talley, D. A. Bayliss, and D. Kim Functional expression of TASK-1/TASK-3 heteromers in cerebellar granule cells J. Physiol., January 1, 2004; 554(1): 64 - 77. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Lauritzen, M. Zanzouri, E. Honore, F. Duprat, M. U. Ehrengruber, M. Lazdunski, and A. J. Patel K+-dependent Cerebellar Granule Neuron Apoptosis: ROLE OF TASK LEAK K+ CHANNELS J. Biol. Chem., August 22, 2003; 278(34): 32068 - 32076. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Hui, D. McIntyre, and R. J. French Conotoxins as Sensors of Local pH and Electrostatic Potential in the Outer Vestibule of the Sodium Channel J. Gen. Physiol., June 30, 2003; 122(1): 63 - 79. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. A. Bayliss, J. E. Sirois, and E. M. Talley The TASK Family: Two-Pore Domain Background K+ Channels Mol. Interv., June 1, 2003; 3(4): 205 - 219. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Hajdu, C. Ulens, G. Panyi, and J. Tytgat Drug- and mutagenesis-induced changes in the selectivity filter of a cardiac two-pore background K+ channel Cardiovasc Res, April 1, 2003; 58(1): 46 - 54. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Czirjak and P. Enyedi Ruthenium Red Inhibits TASK-3 Potassium Channel by Interconnecting Glutamate 70 of the Two Subunits Mol. Pharmacol., March 1, 2003; 63(3): 646 - 652. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. M. Talley and D. A. Bayliss Modulation of TASK-1 (Kcnk3) and TASK-3 (Kcnk9) Potassium Channels. VOLATILE ANESTHETICS AND NEUROTRANSMITTERS SHARE A MOLECULAR SITE OF ACTION J. Biol. Chem., May 10, 2002; 277(20): 17733 - 17742. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. P. Washburn, J. E. Sirois, E. M. Talley, P. G. Guyenet, and D. A. Bayliss Serotonergic Raphe Neurons Express TASK Channel Transcripts and a TASK-Like pH- and Halothane-Sensitive K+ Conductance J. Neurosci., February 15, 2002; 22(4): 1256 - 1265. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Czirjak and P. Enyedi Formation of Functional Heterodimers between the TASK-1 and TASK-3 Two-pore Domain Potassium Channel Subunits J. Biol. Chem., February 8, 2002; 277(7): 5426 - 5432. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| All ASBMB Journals | Molecular and Cellular Proteomics |
| Journal of Lipid Research | ASBMB Today |
