title: FKBP12 modulates gating of the ryanodine receptor/calcium release channel.
abstract: Excitation-contraction (EC) coupling in muscle requires the activation of intracellular calcium release channels (CRC). Four type 1 ryanodine receptor (RyR1) molecules form each tetrameric CRC. Each RyR1 contains a binding site for the FK506 binding protein (FKBP12), a cis-trans peptidyl-prolyl isomerase that is required for coordinated gating of the four RyR1 subunits comprising the channel. When FKBP12 is bound to RyR1, it stabilizes the four subunits that form each CRC. We propose that binding of one FKBP12 to each RyR1 lowers the energy of twisted-amide peptidyl-prolyl bonds and stabilizes RyR1 in a conformation that permits coordinated gating of the four RyR1 subunits.
authors.affiliation: Institute of Molecular Physiology and Genetics, Slovak Academy of Sciences, Bratislava, Slovak Republic.
authors.forename: K
authors.initials: K
authors.lastname: Ondrias
authors.forename: S O
authors.initials: SO
authors.lastname: Marx
authors.forename: M
authors.initials: M
authors.lastname: Gaburjakova
authors.forename: A R
authors.initials: AR
authors.lastname: Marks
mesh_terms: D000818:Animals; D002460:Cell Line; D020104:Immunophilins / Q000502:physiology*; D015640:Ion Channel Gating / Q000502:physiology*; D046911:Macromolecular Substances; D008564:Membrane Potentials; D018482:Muscle, Skeletal / Q000502:physiology; D019696:Peptidylprolyl Isomerase / Q000378:metabolism; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D018411:Spodoptera; D022021:Tacrolimus Binding Proteins; D014162:Transfection
chemical_list: D046911:Macromolecular Substances; D011994:Recombinant Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D022021:Tacrolimus Binding Proteins; D020104:Immunophilins; D019696:Peptidylprolyl Isomerase