| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Biophysical Journal 69: 1780-1788 (1995)
© 1995 the Biophysical Society
Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovak Republic.
ABSTRACT
Single channel activity of the cardiac ryanodine-sensitive calcium-release channel in planar lipid membranes was studied in order to elucidate the calcium-dependent mechanism of its steady-state behavior. The single channel kinetics, observed with Cs+ as the charge carrier at different activating (cis) Ca2+ concentrations in the absence of ATP and Mg2+, were similar to earlier reports and were extended by analysis of channel modal behavior. The channel displayed three episodic levels of open probability defining three gating modes: H (high activity), L (low activity), and I (no activity). The large difference in open probabilities between the two active modes resulted from different bursting patterns and different proportions of two distinct channel open states. I-mode was without openings and can be regarded as the inactivated mode of the channel; L-mode was composed of short and sparse openings; and H-mode openings were longer and grouped into bursts. Modal gating may explain calcium-release channel adaptation (as transient prevalence of H-mode after Ca2+ binding) and the inhibitory effects of drugs (as stabilization of mode I), and it provides a basis for understanding the regulation of calcium release.
This article has been cited by other articles:
 |
|
 |
|
  D. R. Laver and B. N. Honen Luminal Mg2+, A Key Factor Controlling RYR2-mediated Ca2+ Release: Cytoplasmic and Luminal Regulation Modeled in a Tetrameric Channel J. Gen. Physiol., October 1, 2008; 132(4): 429 - 446. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. M. Faber, J. Silva, L. Livshitz, and Y. Rudy Kinetic Properties of the Cardiac L-Type Ca2+ Channel and Its Role in Myocyte Electrophysiology: A Theoretical Investigation Biophys. J., March 1, 2007; 92(5): 1522 - 1543. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Zahradnik, S. Gyorke, and A. Zahradnikova Calcium Activation of Ryanodine Receptor Channels--Reconciling RyR Gating Models with Tetrameric Channel Structure J. Gen. Physiol., October 31, 2005; 126(5): 515 - 527. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. G. Perez, J. A. Copello, Y. Li, K. L. Karko, L. Gomez, J. Ramos-Franco, M. Fill, A. L. Escobar, and R. Mejia-Alvarez Ryanodine receptor function in newborn rat heart Am J Physiol Heart Circ Physiol, May 1, 2005; 288(5): H2527 - H2540. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Hinch, J. L. Greenstein, A. J. Tanskanen, L. Xu, and R. L. Winslow A Simplified Local Control Model of Calcium-Induced Calcium Release in Cardiac Ventricular Myocytes Biophys. J., December 1, 2004; 87(6): 3723 - 3736. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. A. Rosales, M. Fill, and A. L. Escobar Calcium Regulation of Single Ryanodine Receptor Channel Gating Analyzed Using HMM/MCMC Statistical Methods J. Gen. Physiol., April 26, 2004; 123(5): 533 - 553. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Magistretti, D. S. Ragsdale, and A. Alonso Kinetic Diversity of Single-Channel Burst Openings Underlying Persistent Na+ Current in Entorhinal Cortex Neurons Biophys. J., November 1, 2003; 85(5): 3019 - 3034. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Sanchez, C. Hidalgo, and P. Donoso Kinetic Studies of Calcium-Induced Calcium Release in Cardiac Sarcoplasmic Reticulum Vesicles Biophys. J., April 1, 2003; 84(4): 2319 - 2330. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
