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

This Article Full Text Full Text (PDF) All Versions of this Article: 287/1/C36    most recent 00395.2003v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science 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 Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Murayama, T. Articles by Ogawa, Y. Search for Related Content PubMed PubMed Citation Articles by Murayama, T. Articles by Ogawa, Y.

MEMBRANE TRANSPORTERS, ION CHANNELS, AND PUMPS

RyR1 exhibits lower gain of CICR activity than RyR3 in the SR: evidence for selective stabilization of RyR1 channel

Department of Pharmacology, Juntendo University School of Medicine, Tokyo 113-8421, Japan

Submitted 16 September 2003 ; accepted in final form 10 February 2004

We showed that frog -ryanodine receptor (-RyR) had a lower gain of Ca²⁺-induced Ca²⁺ release (CICR) activity than -RyR in sarcoplasmic reticulum (SR) vesicles, indicating selective "stabilization" of the former isoform (Murayama T and Ogawa Y. J Biol Chem 276: 2953–2960, 2001). To know whether this is also the case with mammalian RyR1, we determined [³H]ryanodine binding of RyR1 and RyR3 in bovine diaphragm SR vesicles. The value of [³H]ryanodine binding (B) was normalized by the number of maximal binding sites (B_max), whereby the specific activity of each isoform was expressed. This B/B_max expression demonstrated that ryanodine binding of individual channels for RyR1 was <15% that for RyR3. Responses to Ca²⁺, Mg²⁺, adenine nucleotides, and caffeine were not substantially different between in situ and purified isoforms. These results suggest that the gain of CICR activity of RyR1 is markedly lower than that of RyR3 in mammalian skeletal muscle, indicating selective stabilization of RyR1 as is true of frog -RyR. The stabilization was partly eliminated by FK506 and partly by solubilization of the vesicles with CHAPS, each of which was additive to the other. In contrast, high salt, which greatly enhances [³H]ryanodine binding, caused only a minor effect on the stabilization of RyR1. None of the T-tubule components, coexisting RyR3, or calmodulin was the cause. The CHAPS-sensitive intra- and intermolecular interactions that are common between mammalian and frog skeletal muscles and the isoform-specific inhibition by FKBP12, which is characteristic of mammals, are likely to be the underlying mechanisms.

excitation-contraction coupling; ryanodine binding; ryanodine receptor

This article has been cited by other articles:

				M. Endo Calcium-Induced Calcium Release in Skeletal Muscle Physiol Rev, October 1, 2009; 89(4): 1153 - 1176. [Abstract] [Full Text] [PDF]

				A. Chugun, O. Sato, H. Takeshima, and Y. Ogawa Mg2+ activates the ryanodine receptor type 2 (RyR2) at intermediate Ca2+ concentrations Am J Physiol Cell Physiol, January 1, 2007; 292(1): C535 - C544. [Abstract] [Full Text] [PDF]

				J. Zhou, J. Yi, L. Royer, B. S. Launikonis, A. Gonzalez, J. Garcia, and E. Rios A probable role of dihydropyridine receptors in repression of Ca2+ sparks demonstrated in cultured mammalian muscle Am J Physiol Cell Physiol, February 1, 2006; 290(2): C539 - C553. [Abstract] [Full Text] [PDF]

				R. Rizzuto and T. Pozzan Microdomains of Intracellular Ca2+: Molecular Determinants and Functional Consequences Physiol Rev, January 1, 2006; 86(1): 369 - 408. [Abstract] [Full Text] [PDF]

				T. Murayama, T. Oba, S. Kobayashi, N. Ikemoto, and Y. Ogawa Postulated role of interdomain interactions within the type 1 ryanodine receptor in the low gain of Ca2+-induced Ca2+ release activity of mammalian skeletal muscle sarcoplasmic reticulum Am J Physiol Cell Physiol, June 1, 2005; 288(6): C1222 - C1230. [Abstract] [Full Text] [PDF]

				C. F. Perez, J. R. Lopez, and P. D. Allen Expression levels of RyR1 and RyR3 control resting free Ca2+ in skeletal muscle Am J Physiol Cell Physiol, March 1, 2005; 288(3): C640 - C649. [Abstract] [Full Text] [PDF]