title: Core skeletal muscle ryanodine receptor calcium release complex.
abstract: The core skeletal muscle ryanodine receptor (RyR1) calcium release complex extends through three compartments of the muscle fibre, linking the extracellular environment through the cytoplasmic junctional gap to the lumen of the internal sarcoplasmic reticulum (SR) calcium store. The protein complex is essential for skeletal excitation-contraction (EC)-coupling and skeletal muscle function. Its importance is highlighted by perinatal death if any one of the EC-coupling components are missing and by myopathies associated with mutation of any of the proteins. The proteins essential for EC-coupling include the DHPR α1Ssubunit in the transverse tubule membrane, the DHPR β1asubunit in the cytosol and the RyR1 ion channel in the SR membrane. The other core proteins are triadin and junctin and calsequestrin, associated mainly with SR. These SR proteins are not essential for survival but exert structural and functional influences that modify the gain of EC-coupling and maintain normal muscle function. This review summarises our current knowledge of the individual protein/protein interactions within the core complex and their overall contribution to EC-coupling. We highlight significant areas that provide a continuing challenge for the field. Additional important components of the Ca2+release complex, such as FKBP12, calmodulin, S100A1 and Stac3 are identified and reviewed elsewhere.
authors.affiliation: John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.
authors.forename: Angela F
authors.initials: AF
authors.lastname: Dulhunty
authors.affiliation: Department of Physiology and Pharmacology, University of Rochester Medical Center, Rochester, NY, USA.
authors.forename: Lan
authors.initials: L
authors.lastname: Wei-LaPierre
authors.affiliation: John Curtin School of Medical Research, Australian National University, Canberra, ACT, Australia.
authors.forename: Marco G
authors.initials: MG
authors.lastname: Casarotto
authors.affiliation: Health Research Institute, University of Canberra, Canberra, ACT, Australia.
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Beard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D006801:Humans; D009124:Muscle Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D017433:Protein Structure, Secondary; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D002118:Calcium
keywords: Ca2+ release complex; calsequestrin; excitation-contraction coupling; junctin; ryanodine receptor; skeletal muscle; triadin