title: Characterization of the ryanodine receptor/channel of invertebrate muscle.
abstract: Electron-microscopic analysis was used to show that invertebrate muscle has feetlike structures on the sarcoplasmic reticulum (SR) displaying the typical four-subunit appearance of the calcium (Ca2+) release channel/ryanodine receptor (RyR) observed in vertebrate skeletal muscle (K. E. Loesser, L. Castellani, and C. Franzini-Armstrong. J. Muscle Res. Cell Motil. 13: 161-173, 1992). SR vesicles from invertebrate muscle exhibited specific ryanodine binding and single channel currents that were activated by Ca2+, caffeine, and ATP and inhibited by ruthenium red. The single channel conductance of this invertebrate RyR was lower than that of the vertebrate RyR (49 and 102 pS, respectively). Activation of lobster and scallop SR Ca2+ release channel, in response to cytoplasmic Ca2+ (1 nM-10 mM), reflected a bell-shaped curve, as is found with the mammalian RyR. In contrast to a previous report (J.-H. Seok, L. Xu, N. R. Kramarcy, R. Sealock, and G. Meissner, J. Biol. Chem. 267: 15893-15901, 1992), our results show that regulation of the invertebrate and vertebrate RyRs is quite similar and suggest remarkably similar paths in these diverse organisms.
authors.affiliation: Department of Physiology, University of Connecticut, Farmington 06030, USA.
authors.forename: K E
authors.initials: KE
authors.lastname: Quinn
authors.forename: L
authors.initials: L
authors.lastname: Castellani
authors.forename: K
authors.initials: K
authors.lastname: Ondrias
authors.forename: B E
authors.initials: BE
authors.lastname: Ehrlich
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D015220:Calcium Channels / Q000378:metabolism; D004553:Electric Conductivity; D008051:Lipid Bilayers / Q000378:metabolism; D008854:Microscopy, Electron; D008974:Mollusca; D009132:Muscles / Q000737:chemistry* / Q000502:physiology / Q000648:ultrastructure; D008121:Nephropidae; D012430:Ruthenium Red / Q000494:pharmacology; D012433:Ryanodine / Q000378:metabolism; D019837:Ryanodine Receptor Calcium Release Channel / Q000032:analysis / Q000187:drug effects / Q000502:physiology*; D012519:Sarcoplasmic Reticulum / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure
chemical_list: D015220:Calcium Channels; D008051:Lipid Bilayers; D019837:Ryanodine Receptor Calcium Release Channel; D012430:Ruthenium Red; D012433:Ryanodine; D002110:Caffeine; D000255:Adenosine Triphosphate; D002118:Calcium