The Journal of General Physiology
Cell MicroControls
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text (PDF, 1182K)
Right arrow Alert me when this article is cited
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JGP
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Parent, L.
Right arrow Articles by Coronado, R.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Parent, L.
Right arrow Articles by Coronado, R.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

The Journal of General Physiology, Vol 94, 445-463, Copyright © 1989 by The Rockefeller University Press

ARTICLES

Reconstitution of the ATP-sensitive potassium channel of skeletal muscle. Activation by a G protein-dependent process

L Parent and R Coronado
Department of Physiology and Molecular Biophysics, Baylor College of Medicine, Houston, Texas 77030.

Potassium channels inhibited by adenosine-5'-trisphosphate, K(ATP), found in the transverse tubular membrane of rabbit skeletal muscle were studied using the planar bilayer recording technique. In addition to the single-channel properties of K(ATP) we report its regulation of Mg2+ and by the guanosine-5'-trisphosphate analogue, GTP-y(gamma)-S. The K(ATP) channel (a) has a conductance of 67 pS in 250 mM internal, 50 mM external KCl, and rectifies weakly at holding potentials more positive than 50 mV, (b) is not activated by internal Ca2+ or membrane depolarization, (c) has a permeability ratio PK/PNa greater than 50, and (d) is inhibited by millimolar internal ATP. Activity of K(ATP), measured as open channel probability as a function of time, was unstable at all holding potentials and decreases continuously within a few minutes after a recording is initiated. After a decrease in activity, GTP-y-S (100 microM) added to the internal side reactivated K(ATP) channels but only transiently. In the presence of internal 1 mM Mg2+, GTP-y-S produced a sustained reactivation lasting 20-45 min. Incubation of purified t-tubule vesicles with AlF4 increased the activity of K(ATP) channels, mimicking the effect of GTP-y-S. The effect of AlF4 and the requirement of GTP-y-S plus Mg2+ for sustained channel activation suggests that a nucleotide-binding G protein regulates ATP-sensitive K channels in the t-tuble membrane of rabbit skeletal muscle.
Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:


Home page
 J. Physiol.Home page
J. Camacho, A. Carapia, J. Calvo, M. C Garcia, and J. A Sanchez
Dihydropyridine-sensitive ion currents and charge movement in vesicles derived from frog skeletal muscle plasma membranes
J. Physiol., October 1, 1999; 520(1): 177 - 186.
[Abstract] [Full Text] [PDF]

Home page
 Physiol. Rev.Home page
L. AGUILAR-BRYAN, J. P. CLEMENT IV, G. GONZALEZ, K. KUNJILWAR, A. BABENKO, and J. BRYAN
Toward Understanding the Assembly and Structure of KATP Channels
Physiol Rev, January 1, 1998; 78(1): 227 - 245.
[Abstract] [Full Text] [PDF]


  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents