Cyclic ADP-ribose induces a larger than normal calcium release in malignant hyperthermia-susceptible skeletal muscle fibers

2000 ◽  
Vol 440 (2) ◽  
pp. 236-242 ◽  
Author(s):  
J.R. López ◽  
G. Cordovez ◽  
N. Linares ◽  
P.D. Allen
Keyword(s):  
Skeletal Muscle ◽  
Malignant Hyperthermia ◽  
Calcium Release ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers ◽  
Malignant Hyperthermia Susceptible ◽  
Cyclic Adp Ribose ◽  
Normal Calcium

scholarly journals Growth Associated Protein 43 Is Expressed in Skeletal Muscle Fibers and Is Localized in Proximity of Mitochondria and Calcium Release Units

PLoS ONE ◽  
2013 ◽  
Vol 8 (1) ◽  
pp. e53267 ◽  
Author(s):  
Simone Guarnieri ◽  
Caterina Morabito ◽  
Cecilia Paolini ◽  
Simona Boncompagni ◽  
Raffaele Pilla ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Calcium Release ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers

scholarly journals Spontaneous and Voltage-Activated Elementary Calcium Release Events in Intact Skeletal Muscle Fibers Expressing the Embryonic CaV1.1 Splice Variant

2016 ◽  
Vol 110 (3) ◽  
pp. 97a
Author(s):  
Beatrix Dienes ◽  
János Vincze ◽  
Péter Szentesi ◽  
Nasreen Sultana ◽  
Berhnard E. Flucher ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Splice Variant ◽  
Calcium Release ◽  
Muscle Fibers ◽  
Skeletal Muscle Fibers

Reduced Mg2+ inhibition of Ca2+ release in muscle fibers of pigs susceptible to malignant hyperthermia

1997 ◽  
Vol 272 (1) ◽  
pp. C203-C211 ◽  
Author(s):  
V. J. Owen ◽  
N. L. Taske ◽  
G. D. Lamb
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Malignant Hyperthermia ◽  
Ryanodine Receptor ◽  
Muscle Fiber ◽  
Muscle Fibers ◽  
Inhibitory Effect ◽  
Fiber Bundles ◽  
Force Response ◽  
Skeletal Muscle Fibers

The inhibitory effect of myoplasmic Mg2+ on Ca2+ release from the sarcoplasmic reticulum (SR) was examined in mechanically skinned skeletal muscle fibers from pigs of different ryanodine-receptor (RyR) genotypes. In fibers from pigs homozygous for the normal RyR allele, the free Mg2+ concentration ([Mg2+]) had to be lowered from the normal resting level of 1 to approximately 0.1 mM to induce Ca2+ release and a force response. Fibers from pigs heterozygous or homozygous for the RyR allele associated with malignant hyperthermia (MH) needed only a smaller reduction in free [Mg2+] to induce Ca2+ release (reduction to 0.1-0.2 and > or = 0.2 mM, respectively). Dantrolene (20 microM) counteracted the effect of this reduced Mg2+ inhibition in MH muscle. The response of muscle fiber bundles to the caffeine-halothane contracture test in the three genotypes correlated well with the responsiveness of single fibers to reduced [Mg2+]. Thus the abnormal responsiveness of MH muscle to various stimuli may largely result from the reduced ability of myoplasmic Mg2+ to inhibit Ca2+ release from the SR.

Calsequestrin targeting to sarcoplasmic reticulum of skeletal muscle fibers

2006 ◽  
Vol 291 (2) ◽  
pp. C245-C253 ◽  
Author(s):  
Alessandra Nori ◽  
Giorgia Valle ◽  
Elena Bortoloso ◽  
Federica Turcato ◽  
Pompeo Volpe
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Calcium Binding ◽  
Calcium Release ◽  
Structural Information ◽  
Muscle Fibers ◽  
Physiological Role ◽  
Homogeneous Distribution ◽  
Skeletal Muscle Fibers ◽  
Domain Iii

Calsequestrin (CS) is the low-affinity, high-capacity calcium binding protein segregated to the lumen of terminal cisternae (TC) of the sarcoplasmic reticulum (SR). The physiological role of CS in controlling calcium release from the SR depends on both its intrinsic properties and its localization. The mechanisms of CS targeting were investigated in skeletal muscle fibers and C2C12 myotubes, a model of SR differentiation, with four deletion mutants of epitope (hemagglutinin, HA)-tagged CS: CS-HAΔ24NH2, CS-HAΔ2D, CS-HAΔ3D, and CS-HAΔHT, a double mutant of the NH2 terminus and domain III. As judged by immunofluorescence of transfected skeletal muscle fibers, only the double CS-HA mutant showed a homogeneous distribution at the sarcomeric I band, i.e., it did not segregate to TC. As shown by subfractionation of microsomes derived from transfected skeletal muscles, CS-HAΔHT was largely associated to longitudinal SR whereas CS-HA was concentrated in TC. In C2C12 myotubes, as judged by immunofluorescence, not only CS-HAΔHT but also CS-HAΔ3D and CS-HAΔ2D were not sorted to developing SR. Condensation competence, a property referable to CS oligomerization, was monitored for the several CS-HA mutants in C2C12 myoblasts, and only CS-HAΔ3D was found able to condense. Together, the results indicate that 1) there are at least two targeting sequences at the NH2 terminus and domain III of CS, 2) SR-specific target and structural information is contained in these sequences, 3) heterologous interactions with junctional SR proteins are relevant for segregation, 4) homologous CS-CS interactions are involved in the overall targeting process, and 5) different targeting mechanisms prevail depending on the stage of SR differentiation.

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