Abstract

description): The overall goal of this proposal is to elucidate the multiple regulatory pathways required for ligand-mediated control of the skeletal muscle sarcoplasmic reticulum (SR) calcium release channel or ryanodine receptor (RYR1). Experiments are designed to test two hypotheses. (1) There are discrete domains on RYR1 that mediate its regulation by the dihydropyridine receptor (DHPR), calcium and other endogenous effector molecules. (2) During strenuous muscle exercise and in fatigue, changes in the intracellular ionic milieu and redox state of RYR1 and possibly phosphorylation elicit changes in channel function. The proposal has four specific aims.
Specific aim 1 investigates the regulation of RYR1 by the DHPR and DHPR-derived peptides.
Specific aim 2 determines the kinetics of RYR1 regulation and SR lumenal calcium.
Specific aim 3 determines the levels of endogenous RYR1 S-nitrosylation and characterizes the regulation of RYR1 by NO and NO-generating compounds.
Specific aim 4 defines the relationships between RYR1 protein structure and regulatory mechanisms using site-directed mutagenesis and chimeric constructs. These studies will be conducted in isolated membranes. In addition, purified native and mutant channels will be incorporated into planar lipid bilayers and studied using a ligand binding assay. Experiments will be performed under normal conditions and under conditions mimicking strenuous exercise and fatigue.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR018687-29
Application #
6726068
Study Section
Cardiovascular and Pulmonary Research A Study Section (CVA)
Program Officer
Nuckolls, Glen H
Project Start
1976-05-01
Project End
2005-06-30
Budget Start
2004-05-01
Budget End
2005-06-30
Support Year
29
Fiscal Year
2004
Total Cost
$415,851
Indirect Cost

  Institution

Name
University of North Carolina Chapel Hill
Department
Biochemistry
Type
Schools of Medicine
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599

  Publications

Xu, Le; Mowrey, David D; Chirasani, Venkat R et al. (2018) G4941K substitution in the pore-lining S6 helix of the skeletal muscle ryanodine receptor increases RyR1 sensitivity to cytosolic and luminal Ca2. J Biol Chem 293:2015-2028
Mowrey, David D; Xu, Le; Mei, Yingwu et al. (2017) Ion-pulling simulations provide insights into the mechanisms of channel opening of the skeletal muscle ryanodine receptor. J Biol Chem 292:12947-12958
Meissner, Gerhard (2017) The structural basis of ryanodine receptor ion channel function. J Gen Physiol 149:1065-1089
Xu, Le; Gomez, Angela C; Pasek, Daniel A et al. (2017) Two EF-hand motifs in ryanodine receptor calcium release channels contribute to isoform-specific regulation by calmodulin. Cell Calcium 66:62-70
Mei, Yingwu; Xu, Le; Mowrey, David D et al. (2015) Channel Gating Dependence on Pore Lining Helix Glycine Residues in Skeletal Muscle Ryanodine Receptor. J Biol Chem 290:17535-45
Gillespie, Dirk; Xu, Le; Meissner, Gerhard (2014) Selecting ions by size in a calcium channel: the ryanodine receptor case study. Biophys J 107:2263-73
Chaube, Ruchi; Hess, Douglas T; Wang, Ya-Juan et al. (2014) Regulation of the skeletal muscle ryanodine receptor/Ca2+-release channel RyR1 by S-palmitoylation. J Biol Chem 289:8612-9
Ramachandran, Srinivas; Chakraborty, Asima; Xu, Le et al. (2013) Structural determinants of skeletal muscle ryanodine receptor gating. J Biol Chem 288:6154-65
Manno, Carlo; Figueroa, Lourdes; Royer, Leandro et al. (2013) Altered Ca2+ concentration, permeability and buffering in the myofibre Ca2+ store of a mouse model of malignant hyperthermia. J Physiol 591:4439-57
Mei, Yingwu; Xu, Le; Kramer, Henning F et al. (2013) Stabilization of the skeletal muscle ryanodine receptor ion channel-FKBP12 complex by the 1,4-benzothiazepine derivative S107. PLoS One 8:e54208

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