... membranes [ 1 ]. Within striated muscle, the main strategy for lowering [Ca 2+ ] cyt is through Ca 2+ sequestration in the sarcoplasmic reticulum (SR), a membrane bound organelle which surrounds the contractile myofilaments [ 3 ]. Ca 2+ is transported against a concentration gradient into the SR...

... BY) . Disease mutations Ryanodine receptor Sarcoplasmic reticulum Sudden cardiac death Ventricular fibrillation Ventricular tachyarrhythmias The cardiac ryanodine receptor (RyR2) is a sarcoplasmic reticulum (SR) Ca 2+ release channel essential for excitation–contraction coupling in the heart [ 1...

...Anna N. Malysheva; Kenneth B. Storey; Olga D. Lopina; Alexander M. Rubstov Ca-ATPase activity in sarcoplasmic reticulum (SR) membranes isolated from skeletal muscles of the typical hibernator, the ground squirrel Spermophilus undulatus , is about 2-fold lower than that in SR membranes of rats...

...Walter S. Simonides; Marc H. M. Thelen; C. Gerard van der Linden; Alice Muller; Cornelis van Hardeveld Thyroid hormone increases the Ca 2+ -ATPase activity of the sarcoplasmic reticulum (SR) in skeletal muscle, thereby increasing the energy-turnover associated with Ca 2+ -cycling during contraction...

...Leopoldo de Meis The sarcoplasmic reticulum of skeletal muscle retains a membrane bound Ca 2+ -ATPase which is able to interconvert different forms of energy. A part of the chemical energy released during ATP hydrolysis is converted into heat and in the bibliography it is assumed that the amount...

...Eduardo M. R. Reis; Carolyn W. Slayman; Sergio Verjovski-Almeida In recent years, expression of rabbit sarcoplasmic reticulum (SR) Ca 2+ -ATPase in heterologous systems has been a widely used strategy to study altered enzymes generated by site-directed mutagenesis. Various eukaryotic expression...

... for the development of contractile tension in rat heart myocytes. It is shown that thapsigargin is a valuable probe to examine the importance of SR pools of Ca 2+ and the role of the Ca 2+ ATPase in intact myocytes as well as in genetically altered heart cells. ATPase calcium sarcoplasmic reticulum thapsigargin...

...Giuseppe Inesi; Li Chen; Carlota Sumbilla; David Lewis; Mary E. Kirtley Three experimental systems are described including sarcoplasmic reticulum (SR) vesicles, reconstituted proteoliposomes, and recombinant protein obtained by gene transfer and expression in foreign cells. It is shown that the Ca...

...Tohru Kanazawa; Hiroshi Suzuki; Takashi Daiho; Kazuo Yamasaki Changes in the fluoresence of N -acetyl- N ′-(5-sulfo-1-naphthyl)ethylenediamine (EDANS), being attached to Cys-674 of sarcoplasmic reticulum Ca 2+ -ATPase without affecting the catalytic activity, as well as changes in the intrinsic...

...Gerhard Meissner; Xiangyang Lu Much recent progress has been made in our understanding of the mechanism of sarcoplasmic reticulum Ca 2+ release in skeletal muscle. Vertebrate skeletal muscle excitation-contraction (E-C) coupling is thought to occur by a “mechanical coupling”� mechanism involving...

...Jens Peter Andersen The results of site-directed mutagenesis studies of the sarcoplasmic reticulum Ca 2+ -ATPase are reviewed. More than 250 different point mutants have been expressed in cell culture and analysed by a panel of functional assays. Thereby, 40–50 important amino acid residues have...

...Elisabeth Mintz; Florent Guillain We propose an overview of the mechanism of Ca 2+ transport through the sarcoplasmic reticulum membrane via the Ca 2+ -ATPase. We describe cytoplasmic calcium binding, calcium occlusion in the membrane and lumenal calcium dissociation. A channel-like structure...

...Herman Wolosker; Leopolde de Meis In resting muscle, cytoplasmic Ca 2+ concentration is maintained at a low level by active Ca 2+ transport mediated by the Ca 2+ ATPase from sarcoplasmic reticulum. The region of the protein that contains the catalytic site faces the cytoplasmic side of the membrane...

...Cecilia Hidalgo; Paulina Donoso This article discusses how changes in luminal calcium concentration affect calcium release rates from triad-enriched sarcoplasmic reticulum vesicles, as well as single channel opening probability of the ryanodine receptor/calcium release channels incorporated...

...T. B. Ktenas; T. G. Sotiroudis; A. E. Evangelopoulos Polymyxin B, a cyclic peptide antibiotic, inhibits Ca 2+ -ATPase, p-nitrophenyl phosphatase and phosphorylase kinase activities associated with rabbit skeletal muscle sarcoplasmic reticulum membranes; 50% inhibition is induced by 100 μM, 130μM...

...Marie-Jeanne Loirat; Brigitte Lucas-Heron; Béatrice Ollivier; Claude Leoty Two Ca 2+ sequestering proteins were studied in fast-twitch (EDL) and slow-twitch (soleus) muscle sarcoplasmic reticulum (SR) as a function of denervation time. Ca 2+ -ATPase activity measured in SR fractions of normal...