|
|
|
|
|
|
|
||
The Journal of General Physiology, Vol 89, 253-274, Copyright © 1987 by The Rockefeller University Press
ARTICLES |
T Gonoi and B Hille
Macroscopic Na currents were recorded from N18 neuroblastoma cells by the whole-cell voltage-clamp technique. Inactivation of the Na currents was removed by intracellular application of proteolytic enzymes, trypsin, alpha-chymotrypsin, papain, or ficin, or bath application of N- bromoacetamide. Unlike what has been reported in squid giant axons and frog skeletal muscle fibers, these treatments often increased Na currents at all test pulse potentials. In addition, removal of inactivation gating shifted the midpoint of the peak Na conductance- voltage curve in the negative direction by 26 mV on average and greatly prolonged the rising phase of Na currents for small depolarizations. Polypeptide toxins from Leiurus quinquestriatus scorpion and Goniopora coral, which slow inactivation in adult nerve and muscle cells, also increase the peak Na conductance and shift the peak conductance curve in the negative direction by 7-10 mV in neuroblastoma cells. Control experiments argue against ascribing the shifts to series resistance artifacts or to spontaneous changes of the voltage dependence of Na channel kinetics. The negative shift of the peak conductance curve, the increase of peak Na currents, and the prolongation of the rise at small depolarization after removal of inactivation are consistent with gating kinetic models for neuroblastoma cell Na channels, where inactivation follows nearly irreversible activation with a relatively high, voltage- independent rate constant and Na channels open only once in a depolarization. As the same kind of experiment does not give apparent shifting of activation and prolongation of the rising phase of Na currents in adult axon and muscle membranes, the Na channels of these other membranes probably open more than once in a depolarization.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
This article has been cited by other articles:
|
|
 |
|
  N. Khan, I. P. Gray, C. A. Obejero-Paz, and S. W. Jones Permeation and Gating in CaV3.1 ({alpha}1G) T-type Calcium Channels Effects of Ca2+, Ba2+, Mg2+, and Na+ J. Gen. Physiol., August 1, 2008; 132(2): 223 - 238. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Chakrapani, J. F Cordero-Morales, and E. Perozo A Quantitative Description of KcsA Gating I: Macroscopic Currents J. Gen. Physiol., October 29, 2007; 130(5): 465 - 478. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Ulbricht Sodium Channel Inactivation: Molecular Determinants and Modulation Physiol Rev, October 1, 2005; 85(4): 1271 - 1301. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. V. Tabarean and T. Narahashi Kinetics of Modulation of Tetrodotoxin-Sensitive and Tetrodotoxin-Resistant Sodium Channels by Tetramethrin and Deltamethrin J. Pharmacol. Exp. Ther., December 1, 2001; 299(3): 988 - 997. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Kinoshita, H. Maejima, K. Yamaoka, K. Konno, N. Kawai, E. Shimizu, S. Yokote, H. Nakayama, and I. Seyama Novel Wasp Toxin Discriminates between Neuronal and Cardiac Sodium Channels Mol. Pharmacol., June 1, 2001; 59(6): 1457 - 1463. [Abstract] [Full Text]
|
|
|
|
 |
|
 C.-C. Kuo and S. Yang Recovery from Inactivation of T-Type Ca2+ Channels in Rat Thalamic Neurons J. Neurosci., March 15, 2001; 21(6): 1884 - 1892. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z.-W. Li, J. P. Ding, V. Kalyanaraman, and C. J. Lingle RINm5f Cells Express Inactivating BK Channels Whereas HIT Cells Express Noninactivating BK Channels J Neurophysiol, February 1, 1999; 81(2): 611 - 624. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y. Li-Smerin and K. J. Swartz Gating modifier toxins reveal a conserved structural motif in voltage-gated Ca2+ and K+ channels PNAS, July 21, 1998; 95(15): 8585 - 8589. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Lipski, Y. Kawai, J. Qi, A. Comer, and J. Win Whole cell patch-clamp study of putative vasomotor neurons isolated from the rostral ventrolateral medulla Am J Physiol Regulatory Integrative Comp Physiol, April 1, 1998; 274(4): R1099 - R1110. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Chen, V. D. Fitzpatrick, R. L. Vandlen, and A. H. Tashjian Jr. Both Overlapping and Distinct Signaling Pathways for Somatostatin Receptor Subtypes SSTR1 and SSTR2 in Pituitary Cells J. Biol. Chem., July 25, 1997; 272(30): 18666 - 18672. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. D. Baker and H. Bostock Low-Threshold, Persistent Sodium Current in Rat Large Dorsal Root Ganglion Neurons in Culture J Neurophysiol, March 1, 1997; 77(3): 1503 - 1513. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Kellenberger, T. Scheuer, and W. A. Catterall Movement of the Na+ Channel Inactivation Gate during Inactivation J. Biol. Chem., November 29, 1996; 271(48): 30971 - 30979. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Klöckner, G. Mikala, M. Varadi, G. Varadi, and A. Schwartz Involvement of the Carboxyl-terminal Region of the [IMAGE][IMAGE] Subunit in Voltage-dependent Inactivation of Cardiac Calcium Channels J. Biol. Chem., July 21, 1995; 270(29): 17306 - 17310. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. C. McPhee, D. S. Ragsdale, T. Scheuer, and W. A. Catterall A Critical Role for Transmembrane Segment IVS6 of the Sodium Channel [IMAGE] Subunit in Fast Inactivation J. Biol. Chem., May 19, 1995; 270(20): 12025 - 12034. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Solaro and C. Lingle Trypsin-sensitive, rapid inactivation of a calcium-activated potassium channel Science, September 18, 1992; 257(5077): 1694 - 1698. [Abstract] [PDF]
|
|
|
|
|
|
T Hoshi, W. Zagotta, and R. Aldrich Biophysical and molecular mechanisms of Shaker potassium channel inactivation Science, October 26, 1990; 250(4980): 533 - 538. [Abstract] [PDF]
|
|
|
|
|
|
W. Catterall Structure and function of voltage-sensitive ion channels Science, October 7, 1988; 242(4875): 50 - 61. [Abstract] [PDF]
|
|
|
|
|
|
P. Vassilev, T Scheuer, and W. Catterall Identification of an intracellular peptide segment involved in sodium channel inactivation Science, September 23, 1988; 241(4873): 1658 - 1661. [Abstract] [PDF]
|
|
|
|
