|
|
|
|
|
|
|
||
J. Gen. Physiol.,
Volume 111, Number 6, June 1, 1998 781-794
§§
§
From the * Department of Molecular Biophysics and Physiology, Rush Presbyterian St. Luke's Medical Center, Chicago, Illinois 60612; A voltage-gated K+ conductance resembling that of the human ether-à-go-go-related gene product
(HERG) was studied using whole-cell voltage-clamp recording, and found to be the predominant conductance at
hyperpolarized potentials in a cell line (MLS-9) derived from primary cultures of rat microglia. Its behavior differed markedly from the classical inward rectifier K+ currents described previously in microglia, but closely resembled HERG currents in cardiac muscle and neuronal tissue. The HERG-like channels opened rapidly on hyperpolarization from 0 mV, and then decayed slowly into an absorbing closed state. The peak K+ conductance-voltage
relation was half maximal at Playfair Neuroscience Unit, Toronto Hospital Research Institute, Toronto, Ontario M5T 2S8, Canada; § Department of Physiology,
University of Toronto, Toronto, Ontario M5S 1A1, Canada; and Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S
2S2, Canada
59 mV with a slope factor of 18.6 mV. Availability, assessed by a hyperpolarizing test
pulse from different holding potentials, was more steeply voltage dependent, and the midpoint was more positive
(14 vs. 39 mV) when determined by making the holding potential progressively more positive than more negative. The origin of this hysteresis is explored in a companion paper (Pennefather, P.S., W. Zhou, and T.E. DeCoursey. 1998. J. Gen. Physiol. 111:795-805). The pharmacological profile of the current differed from classical inward rectifier but closely resembled HERG. Block by Cs+ or Ba2+ occurred only at millimolar concentrations, La3+
blocked with Ki = ~40 µM, and the HERG-selective blocker, E-4031, blocked with Ki = 37 nM. Implications of the
presence of HERG-like K+ channels for the ontogeny of microglia are discussed.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  E. F. Vernon-Wilson, F. Aurade, L. Tian, I. C. M. Rowe, M. J. Shipston, J. Savill, and S. B. Brown CD31 delays phagocyte membrane repolarization to promote efficient binding of apoptotic cells J. Leukoc. Biol., November 1, 2007; 82(5): 1278 - 1288. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Zhang, X.-S. Liu, S. Diochot, M. Lazdunski, and G.-N. Tseng APETx1 from Sea Anemone Anthopleura elegantissima Is a Gating Modifier Peptide Toxin of the Human Ether-a-go-go- Related Potassium Channel Mol. Pharmacol., August 1, 2007; 72(2): 259 - 268. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G.-N. Tseng, K. D. Sonawane, Y. V. Korolkova, M. Zhang, J. Liu, E. V. Grishin, and H. R. Guy Probing the Outer Mouth Structure of the hERG Channel with Peptide Toxin Footprinting and Molecular Modeling Biophys. J., May 15, 2007; 92(10): 3524 - 3540. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Beeton and K. G. Chandy Potassium Channels, Memory T Cells, and Multiple Sclerosis Neuroscientist, December 1, 2005; 11(6): 550 - 562. [Abstract] [PDF]
|
|
|
|
 |
|
 P. Miranda, T. Giraldez, P. de la Pena, D. G Manso, C. Alonso-Ron, D. Gomez-Varela, P. Dominguez, and F. Barros Specificity of TRH receptor coupling to G-proteins for regulation of ERG K+ channels in GH3 rat anterior pituitary cells J. Physiol., August 1, 2005; 566(3): 717 - 736. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Kim, K. M. Boyle, and J. L. Carroll Postnatal development of E-4031-sensitive potassium current in rat carotid chemoreceptor cells J Appl Physiol, April 1, 2005; 98(4): 1469 - 1477. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Beeton, M. W. Pennington, H. Wulff, S. Singh, D. Nugent, G. Crossley, I. Khaytin, P. A. Calabresi, C.-Y. Chen, G. A. Gutman, et al. Targeting Effector Memory T Cells with a Selective Peptide Inhibitor of Kv1.3 Channels for Therapy of Autoimmune Diseases Mol. Pharmacol., April 1, 2005; 67(4): 1369 - 1381. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Zhang, J. Liu, and G.-N. Tseng Gating Charges in the Activation and Inactivation Processes of the hERG Channel J. Gen. Physiol., November 29, 2004; 124(6): 703 - 718. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Zhu, C. M. Golden, J. Ye, X.-Y. Wang, H. I. Akbarali, and J. D. Huizinga ERG K+ currents regulate pacemaker activity in ICC Am J Physiol Gastrointest Liver Physiol, December 1, 2003; 285(6): G1249 - G1258. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Dallas, X. Zhu, S. Baruchel, L. Schlichter, and R. Bendayan Functional Expression of the Multidrug Resistance Protein 1 in Microglia J. Pharmacol. Exp. Ther., October 1, 2003; 307(1): 282 - 290. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J.-H. Liu, S. Konig, M. Michel, S. Arnaudeau, J. Fischer-Lougheed, C. R. Bader, and L. Bernheim Acceleration of human myoblast fusion by depolarization: graded Ca2+ signals involved Development, August 1, 2003; 130(15): 3437 - 3446. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Farrelly, S. Ro, B. P. Callaghan, M. A. Khoyi, N. Fleming, B. Horowitz, K. M. Sanders, and K. D. Keef Expression and function of KCNH2 (HERG) in the human jejunum Am J Physiol Gastrointest Liver Physiol, June 1, 2003; 284(6): G883 - G895. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Zhang, Y. V. Korolkova, J. Liu, M. Jiang, E. V. Grishin, and G.-N. Tseng BeKm-1 Is a HERG-Specific Toxin that Shares the Structure with ChTx but the Mechanism of Action with ErgTx1 Biophys. J., May 1, 2003; 84(5): 3022 - 3036. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Shoeb, A. P. Malykhina, and H. I. Akbarali Cloning and Functional Characterization of the Smooth Muscle Ether-a-go-go-related Gene K+ Channel. POTENTIAL ROLE OF A CONSERVED AMINO ACID SUBSTITUTION IN THE S4 REGION J. Biol. Chem., January 17, 2003; 278(4): 2503 - 2514. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. S. Cayabyab, F. W. L. Tsui, and L. C. Schlichter Modulation of the ERG K+ Current by the Tyrosine Phosphatase, SHP-1 J. Biol. Chem., December 6, 2002; 277(50): 48130 - 48138. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Ohya, B. Horowitz, and I. A. Greenwood Functional and molecular identification of ERG channels in murine portal vein myocytes Am J Physiol Cell Physiol, September 1, 2002; 283(3): C866 - C877. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A. M. Smith, H.-W. Tsui, E. W. Newell, X. Jiang, X.-P. Zhu, F. W. L. Tsui, and L. C. Schlichter Functional Up-regulation of HERG K+ Channels in Neoplastic Hematopoietic Cells J. Biol. Chem., May 17, 2002; 277(21): 18528 - 18534. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. S. Cayabyab and L. C. Schlichter Regulation of an ERG K+ Current by Src Tyrosine Kinase J. Biol. Chem., April 12, 2002; 277(16): 13673 - 13681. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Lee, L. Schlichter, M. Bendayan, and R. Bendayan Functional Expression of P-glycoprotein in Rat Brain Microglia J. Pharmacol. Exp. Ther., October 1, 2001; 299(1): 204 - 212. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Khanna, L. Roy, X. Zhu, and L. C. Schlichter K+ channels and the microglial respiratory burst Am J Physiol Cell Physiol, April 1, 2001; 280(4): C796 - C806. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Hong, L. Schlichter, and R. Bendayan A Novel Zidovudine Uptake System in Microglia J. Pharmacol. Exp. Ther., January 1, 2001; 296(1): 141 - 149. [Abstract] [Full Text]
|
|
|
|
 |
|
 A. Emmi, H. J. Wenzel, P. A. Schwartzkroin, M. Taglialatela, P. Castaldo, L. Bianchi, J. Nerbonne, G. A. Robertson, and D. Janigro Do Glia Have Heart? Expression and Functional Role for Ether-A-Go-Go Currents in Hippocampal Astrocytes J. Neurosci., May 15, 2000; 20(10): 3915 - 3925. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. L. Overholt, E. Ficker, T. Yang, H. Shams, G. R. Bright, and N. R. Prabhakar HERG-Like Potassium Current Regulates the Resting Membrane Potential in Glomus Cells of the Rabbit Carotid Body J Neurophysiol, March 1, 2000; 83(3): 1150 - 1157. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Hong, L. Schlichter, and R. Bendayan A Na+-Dependent Nucleoside Transporter in Microglia J. Pharmacol. Exp. Ther., January 1, 2000; 292(1): 366 - 374. [Abstract] [Full Text]
|
|
|
|
|
|
S. A. Kotecha and L. C. Schlichter A Kv1.5 to Kv1.3 Switch in Endogenous Hippocampal Microglia and a Role in Proliferation J. Neurosci., December 15, 1999; 19(24): 10680 - 10693. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. I. Akbarali, H. Thatte, X. D. He, W. R. Giles, and R. K. Goyal Role of HERG-like K+ currents in opossum esophageal circular smooth muscle Am J Physiol Cell Physiol, December 1, 1999; 277(6): C1284 - C1290. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. M Roden and J. R Balser A plethora of mechanisms in the HERG-related long QT syndrome: Genetics meets electrophysiology Cardiovasc Res, November 1, 1999; 44(2): 242 - 246. [Full Text] [PDF]
|
|
|
|
|
|
C. Eder Ion channels in microglia (brain macrophages) Am J Physiol Cell Physiol, August 1, 1998; 275(2): C327 - C342. [Abstract] [Full Text] [PDF]
|
|
|
|
