Biophys J, July 1999, p. 189-203, Vol. 77, No. 1

Activation and Inhibition of Skeletal RyR Channels by a Part of the Skeletal DHPR II-III Loop: Effects of DHPR Ser⁶⁸⁷ and FKBP12

Muscle Research Group, John Curtin School of Medical Research, Canberra, ACT 2601, Australia

Peptides, corresponding to sequences in the N-terminal region of the skeletal muscle dihydropyridine receptor (DHPR) II-III loop, have been tested on sarcoplasmic reticulum (SR) Ca²⁺ release and ryanodine receptor (RyR) activity. The peptides were: A1, Thr⁶⁷¹-Leu⁶⁹⁰; A2, Thr⁶⁷¹-Leu⁶⁹⁰ with Ser⁶⁸⁷ Ala substitution; NB, Gly⁶⁸⁹-Lys⁷⁰⁸ and A1S, scrambled A1 sequence. The relative rates of peptide-induced Ca²⁺ release from normal (FKBP12+) SR were A2 > A1 > A1S > NB. Removal of FKBP12 reduced the rate of A1-induced Ca²⁺ release by ~30%. A1 and A2 (but not NB or A1S), in the cytoplasmic (cis) solution, either activated or inhibited single FKBP12+ RyRs. Maximum activation was seen at 40 mV, with 10 µM A1 or 50 nM A2. The greatest A1-induced increase in mean current (sixfold) was seen with 100 nM cis Ca²⁺. Inhibition by A1 was greatest at +40 mV (or when permeant ions flowed from cytoplasm to SR lumen) with 100 µM cis Ca²⁺, where channel activity was almost fully inhibited. A1 did not activate FKBP12-stripped RyRs, although peptide-induced inhibition remained. The results show that peptide A activation of RyRs does not require DHPR Ser⁶⁸⁷, but required FKBP12 binding to RyRs. Peptide A must interact with different sites to activate or inhibit RyRs, because current direction-, voltage-, cis [Ca²⁺]-, and FKBP12-dependence of activation and inhibition differ.

Biophys J, July 1999, p. 189-203, Vol. 77, No. 1
© 1999 by the Biophysical Society   0006-3495/99/07/189/15  $2.00

This article has been cited by other articles:

				Q. Zhou, Q.-L. Wang, X. Meng, Y. Shu, T. Jiang, T. Wagenknecht, C.-C. Yin, S.-F. Sui, and Z. Liu Structural and Functional Characterization of Ryanodine Receptor-Natrin Toxin Interaction Biophys. J., November 1, 2008; 95(9): 4289 - 4299. [Abstract] [Full Text] [PDF]

				S. Pouvreau, L. Csernoch, B. Allard, J. M. Sabatier, M. De Waard, M. Ronjat, and V. Jacquemond Transient Loss of Voltage Control of Ca2+ Release in the Presence of Maurocalcine in Skeletal Muscle Biophys. J., September 15, 2006; 91(6): 2206 - 2215. [Abstract] [Full Text] [PDF]

				L. Wei, M. Varsanyi, A. F. Dulhunty, and N. A. Beard The Conformation of Calsequestrin Determines Its Ability to Regulate Skeletal Ryanodine Receptors Biophys. J., August 15, 2006; 91(4): 1288 - 1301. [Abstract] [Full Text] [PDF]

				M. R. Sharma, L. H. Jeyakumar, S. Fleischer, and T. Wagenknecht Three-Dimensional Visualization of FKBP12.6 Binding to an Open Conformation of Cardiac Ryanodine Receptor Biophys. J., January 1, 2006; 90(1): 164 - 172. [Abstract] [Full Text] [PDF]

				S. Papadopoulos, V. Leuranguer, R. A. Bannister, and K. G. Beam Mapping Sites of Potential Proximity between the Dihydropyridine Receptor and RyR1 in Muscle Using a Cyan Fluorescent Protein-Yellow Fluorescent Protein Tandem as a Fluorescence Resonance Energy Transfer Probe J. Biol. Chem., October 15, 2004; 279(42): 44046 - 44056. [Abstract] [Full Text] [PDF]

				N. M. Lorenzon, C. S. Haarmann, E. E. Norris, S. Papadopoulos, and K. G. Beam Metabolic Biotinylation as a Probe of Supramolecular Structure of the Triad Junction in Skeletal Muscle J. Biol. Chem., October 15, 2004; 279(42): 44057 - 44064. [Abstract] [Full Text] [PDF]

				E. M. Gallant, J. Hart, K. Eager, S. Curtis, and A. F. Dulhunty Caffeine sensitivity of native RyR channels from normal and malignant hyperthermic pigs: effects of a DHPR II-III loop peptide Am J Physiol Cell Physiol, April 1, 2004; 286(4): C821 - C830. [Abstract] [Full Text] [PDF]

				A. F. Dulhunty, S. M. Curtis, S. Watson, L. Cengia, and M. G. Casarotto Multiple Actions of Imperatoxin A on Ryanodine Receptors: INTERACTIONS WITH THE II-III LOOP "A" FRAGMENT J. Biol. Chem., March 19, 2004; 279(12): 11853 - 11862. [Abstract] [Full Text] [PDF]

				G. Avila, E. H. Lee, C. F. Perez, P. D. Allen, and R. T. Dirksen FKBP12 Binding to RyR1 Modulates Excitation-Contraction Coupling in Mouse Skeletal Myotubes J. Biol. Chem., June 13, 2003; 278(25): 22600 - 22608. [Abstract] [Full Text] [PDF]

				L. Chen, E. Esteve, J.-M. Sabatier, M. Ronjat, M. De Waard, P. D. Allen, and I. N. Pessah Maurocalcine and Peptide A Stabilize Distinct Subconductance States of Ryanodine Receptor Type 1, Revealing a Proportional Gating Mechanism J. Biol. Chem., April 25, 2003; 278(18): 16095 - 16106. [Abstract] [Full Text] [PDF]

				C. Proenza, J. O'Brien, J. Nakai, S. Mukherjee, P. D. Allen, and K. G. Beam Identification of a Region of RyR1 That Participates in Allosteric Coupling with the alpha 1S (CaV1.1) II-III Loop J. Biol. Chem., February 15, 2002; 277(8): 6530 - 6535. [Abstract] [Full Text] [PDF]

				C. M. Wilkens, N. Kasielke, B. E. Flucher, K. G. Beam, and M. Grabner Excitation-contraction coupling is unaffected by drastic alteration of the sequence surrounding residues L720-L764 of the alpha 1S II-III loop PNAS, April 24, 2001; (2001) 101618098. [Abstract] [Full Text]

				G. D. Lamb, R. El-Hayek, N. Ikemoto, and D. G. Stephenson Effects of dihydropyridine receptor II-III loop peptides on Ca2+ release in skinned skeletal muscle fibers Am J Physiol Cell Physiol, October 1, 2000; 279(4): C891 - C905. [Abstract] [Full Text] [PDF]

				M. G. Casarotto, F. Gibson, S. M. Pace, S. M. Curtis, M. Mulcair, and A. F. Dulhunty A Structural Requirement for Activation of Skeletal Ryanodine Receptors by Peptides of the Dihydropyridine Receptor II-III Loop J. Biol. Chem., April 14, 2000; 275(16): 11631 - 11637. [Abstract] [Full Text] [PDF]

				C. Proenza, C. M. Wilkens, and K. G. Beam Excitation-Contraction Coupling Is Not Affected by Scrambled Sequence in Residues 681-690 of the Dihydropyridine Receptor II-III Loop J. Biol. Chem., September 22, 2000; 275(39): 29935 - 29937. [Abstract] [Full Text] [PDF]

				A. Dulhunty, P. Gage, S. Curtis, G. Chelvanayagam, and P. Board The Glutathione Transferase Structural Family Includes a Nuclear Chloride Channel and a Ryanodine Receptor Calcium Release Channel Modulator J. Biol. Chem., January 26, 2001; 276(5): 3319 - 3323. [Abstract] [Full Text] [PDF]

				T. Yamamoto and N. Ikemoto T-tubule Depolarization-induced Local Events in the Ryanodine Receptor, as Monitored with the Fluorescent Conformational Probe Incorporated by Mediation of Peptide A J. Biol. Chem., January 4, 2002; 277(2): 984 - 992. [Abstract] [Full Text] [PDF]

				T. Yamamoto, J. Rodriguez, and N. Ikemoto Ca2+-dependent Dual Functions of Peptide C. THE PEPTIDE CORRESPONDING TO THE Glu724-Pro760 REGION (THE SO-CALLED DETERMINANT OF EXCITATION-CONTRACTION COUPLING) OF THE DIHYDROPYRIDINE RECEPTOR alpha 1 SUBUNIT II-III LOOP J. Biol. Chem., January 4, 2002; 277(2): 993 - 1001. [Abstract] [Full Text] [PDF]

				C. M. Wilkens, N. Kasielke, B. E. Flucher, K. G. Beam, and M. Grabner Excitation-contraction coupling is unaffected by drastic alteration of the sequence surrounding residues L720-L764 of the alpha 1S II-III loop PNAS, May 8, 2001; 98(10): 5892 - 5897. [Abstract] [Full Text] [PDF]