HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Shui, Z Articles by Kameyama, K Search for Related Content PubMed PubMed Citation Articles by Shui, Z Articles by Kameyama, K

Department of Physiology, University of Leeds, UK.

1. Activity of rat atrial muscarinic K+ channels has been measured in five configurations of the patch clamp technique. 2. In configurations in which the normal intracellular solution was lost, the slow phase of desensitization (a slow decline of channel activity during an exposure to ACh) was much reduced (or absent) and deactivation (on wash-off of ACh) was slowed as compared with desensitization and deactivation in configurations in which normal intracellular solution was retained. This suggests that soluble intracellular regulators are involved in these processes. 3. When a G protein-coupled receptor kinase (GRK2) was applied to the cytoplasmic surface of conventional outside-out patches in the presence of ATP, the slow phase of desensitization was restored. In the absence of ATP, GRK2 failed to restore the slow phase. 4. It is concluded that (i) G protein-coupled receptor kinase dependent phosphorylation of the muscarinic receptor is responsible for the slow phase of desensitization and (ii) a soluble factor (such as a GTPase activating protein or 'GAP') is responsible for normal rapid deactivation.

This article has been cited by other articles:

				N. Voigt, A. Friedrich, M. Bock, E. Wettwer, T. Christ, M. Knaut, R. H. Strasser, U. Ravens, and D. Dobrev Differential phosphorylation-dependent regulation of constitutively active and muscarinic receptor-activated IK,ACh channels in patients with chronic atrial fibrillation Cardiovasc Res, June 1, 2007; 74(3): 426 - 437. [Abstract] [Full Text] [PDF]

				T. T. Yamanushi, Z. Shui, R. N. Leach, H. Dobrzynski, T. W. Claydon, and M. R. Boyett Role of internalization of M2 muscarinic receptor via clathrin-coated vesicles in desensitization of the muscarinic K+ current in heart Am J Physiol Heart Circ Physiol, April 1, 2007; 292(4): H1737 - H1746. [Abstract] [Full Text] [PDF]

				T. Sickmann and C. Alzheimer Short-Term Desensitization of G-Protein-Activated, Inwardly Rectifying K+ (GIRK) Currents in Pyramidal Neurons of Rat Neocortex J Neurophysiol, October 1, 2003; 90(4): 2494 - 2503. [Abstract] [Full Text] [PDF]

				H. Cho, J.-Y. Hwang, D. Kim, H.-S. Shin, Y. Kim, Y. E. Earm, and W.-K. Ho Acetylcholine-induced Phosphatidylinositol 4,5-Bisphosphate Depletion Does Not Cause Short-term Desensitization of G Protein-gated Inwardly Rectifying K+ Current in Mouse Atrial Myocytes J. Biol. Chem., July 26, 2002; 277(31): 27742 - 27747. [Abstract] [Full Text] [PDF]