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Neural control on the activity of the sarcoplasmic reticulum of rat skeletal muscle
No full textNeural control on the activity of the calcium-transport system in sarcoplasmic reticulum of rat skeletal muscle.
Margreth A, Salviati G, Carraro U.
Nature. 1973 Jan 26;241(5387):285-6. No abstract available.
PMID:
4267181
[PubMed - indexed for MEDLINE
Structural membrane proteins and loosely associated proteins of the sarcoplasmic reticulum
Full text linkBiochem J. 1974 Jun;139(3):509-13.
Structural membrane proteins and loosely associated proteins of the sarcoplasmic reticulum.
Margreth A, Carraro U, Salviati G.
Abstract
The protein composition of sarcoplasmic-reticulum vesicles, either unpurified or after fractionation on sucrose gradients, and with or without previous osmotic shock and sonication, was investigated by electrophoresis in acid polyacrylamide gels. The pattern of release of loosely bound proteins is discussed with respect to their localization in the interior of the vesicles.
PMID:
4369219
[PubMed - indexed for MEDLINE]
PMCID: PMC1166315
Free PMC Articl
Characterization of calsequestrin of avian skeletal muscle.
No full textA calsequentrin (CS)-like glycoprotein is present in the sarcoplasmic reticulum (SR) of chicken pectoralis muscle, which displays unusual properties: it binds relatively low amounts of Ca2+, compared to CS in mammalian skeletal muscle (Yap & MacLennan, 1976), it does not exhibit a marked pH-dependent shift in mobility in sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and its metachromatic staining properties with Stains All are likewise peculiar (Damiani et al., 1986). We have now definitively localized the same protein to the junctional terminal cisternae (TC) fraction of the SR of chicken pectoralis muscle and have further characterized it, following purification by crystallization with Ca2+ and by Ca2(+)-dependent elution from phenyl-Sepharose columns. The purified protein (apparent Mr: 51 kDa), isoelectrofocuses at pH 4.5, and is readily identified on blots by a 45Ca overlay technique, similar to CS of rabbit skeletal muscle, but it binds half as much Ca2+ (about 20 moles of Ca2+ per mole of protein), as estimated by equilibrium dialysis. However, the chicken protein shares extensive similarities with mammalian CSs, concerning Ca2(+)-induced changes in maximum intrinsic fluorescence and the Ca2(+)-modulated interaction with phenyl-Sepharose, as well as in being protected by Ca2+ from proteolysis by either trypsin or chymotrypsin. We discuss how the presence of a Ca2(+)-regulated hydrophobic site in the CS molecule appears to be the most invariant property of the CS-family of Ca2(+)-binding proteins
Direct photoaffinity labeling of junctional sarcoplasmic reticulum with [14C]doxorubicin.
Full text linkDoxorubicin, an anticancer drug, induces Ca2+ release from the terminal cisternae (TC) of skeletal muscle (Zorzato, F., Salviati, G., Facchinetti, T., and Volpe, P. (1985) J. Biol. Chem. 260, 7349-7355). Long wave ultraviolet irradiation of a TC fraction with morphologically intact feet structures (Saito, A., Seiler, S., Chu, A., and Fleischer, S. (1984) J. Cell Biol. 99, 875-885) in the presence of [14C]doxorubicin, led to covalent photolabeling of two proteins that exhibited apparent Mr values of 350,000 and 170,000. Such proteins were found to be absent in a fraction of longitudinal sarcoplasmic reticulum but enriched in junctional face membranes obtained by Triton X-100 treatment of the TC fraction. Three additional proteins with Mr values of 80,000, 60,000, and 30,000 were also faintly labeled in the junctional face membrane fraction. On a molar basis the highest level of incorporation was found in the 170,000-Da protein, probably a Ca2+-binding protein (Campbell, K. P., MacLennan, D. H., and Jorgensen, A. O. (1983) J. Biol. Chem. 258, 11267-11273). A lower level of labeling was observed in the 350,000-Da protein, tentatively identified as a component of the feet structures (Cadwell, J. J. S., and Caswell, A. H. (1982) J. Cell Biol. 93, 543-550). Photolabeling of junctional TC proteins did not occur if a 10-50-fold excess cold doxorubicin was included in the assay medium, indicating that it was displaceable and specific, and if ultraviolet irradiation was omitted. Photolabeling was inhibited by caffeine or ruthenium red, i.e. by an activator and an inhibitor of Ca2+ release from TC, respectively. Furthermore, photolabeling was prevented by [ethylenebis(oxyethylenenitrilo)]tetraacetic acid suggesting that doxorubicin binding is Ca2+-dependent. Doxorubicin-binding proteins are constituents of the junctional sarcoplasmic reticulum and might be involved in modulating Ca2+ release from TC
Direct photoaffinity labeling of junctional sarcoplasmic reticulum with [14C]doxorubicin
No full textDoxorubicin, an anticancer drug, induces Ca2+ release from the terminal cisternae (TC) of skeletal muscle (Zorzato, F., Salviati, G., Facchinetti, T., and Volpe, P. (1985) J. Biol. Chem. 260, 7349-7355). Long wave ultraviolet irradiation of a TC fraction with morphologically intact feet structures (Saito, A., Seiler, S., Chu, A., and Fleischer, S. (1984) J. Cell Biol. 99, 875-885) in the presence of [14C]doxorubicin, led to covalent photolabeling of two proteins that exhibited apparent Mr values of 350,000 and 170,000. Such proteins were found to be absent in a fraction of longitudinal sarcoplasmic reticulum but enriched in junctional face membranes obtained by Triton X-100 treatment of the TC fraction. Three additional proteins with Mr values of 80,000, 60,000, and 30,000 were also faintly labeled in the junctional face membrane fraction. On a molar basis the highest level of incorporation was found in the 170,000-Da protein, probably a Ca2+-binding protein (Campbell, K. P., MacLennan, D. H., and Jorgensen, A. O. (1983) J. Biol. Chem. 258, 11267-11273). A lower level of labeling was observed in the 350,000-Da protein, tentatively identified as a component of the feet structures (Cadwell, J. J. S., and Caswell, A. H. (1982) J. Cell Biol. 93, 543-550). Photolabeling of junctional TC proteins did not occur if a 10-50-fold excess cold doxorubicin was included in the assay medium, indicating that it was displaceable and specific, and if ultraviolet irradiation was omitted. Photolabeling was inhibited by caffeine or ruthenium red, i.e. by an activator and an inhibitor of Ca2+ release from TC, respectively. Furthermore, photolabeling was prevented by [ethylenebis(oxyethylenenitrilo)]tetraacetic acid suggesting that doxorubicin binding is Ca2+-dependent. Doxorubicin-binding proteins are constituents of the junctional sarcoplasmic reticulum and might be involved in modulating Ca2+ release from TC
Identification of two ryanodine receptor transcripts in neonatal, slow-, and fast-twitch rabbit skeletal muscles
No full textAnalysis of the primary structure of the rabbit skeletal muscle ryanodine receptor led to the identification of two molecules of 5032 and 5037 residues, respectively. Such a sequence discrepancy is likely to be due to the alternative splicing of a 15 bp exon (1) encoding a 5 amino acid insertion (Ala-Gly-Asp-Ala-Gln) after residue 3479. By using PCR on first strand cDNA, we searched for the 15 base pair insertion in the ryanodine receptor mRNA from adult slow- and fast-twitch skeletal muscle, as well as from fast-muscles, at various stages of post-natal development. All rabbit skeletal muscle mRNAs, regardless of their developmental stage and twitch properties, contain two RYR transcripts, suggesting the coexistence of two RYR isoforms in mammalian skeletal muscl
Relationship of serum enzyme changes to muscle damage in vitamin E deficiency of the rabbit
No full textIsolation of terminal cisternae of frog skeletal muscle. Calcium storage and release properties.
Full text linkSarcoplasmic reticulum (SR) terminal cisternae (TC) of frog (Rana esculenta) fast-twitch skeletal muscle have been purified by isopycnic sucrose density gradient centrifugation. Biochemical characteristics and Ca2+ release properties have been investigated and compared to those of the homologous fraction of rabbit skeletal muscle TC. The frog SR fraction obtained at the 38/45% sucrose interface appears to be derived from the terminal cisternae region as judged by: (a) thin section electron microscopy showing vesicles containing electron opaque material and squarelike (feet) projections at the outer surface; (b) protein composition (Ca2+-ATPase, calsequestrin, and high Mr proteins); (c) Ca2+ fluxes properties. The content of calsequestrin was higher in frog TC by 50% and the Ca2+ binding capacity (624 or 45 nmol of Ca2+/mg of TC protein, depending upon experimental conditions) was 3-4 times that of rabbit TC. Species-specific antigenic differences were found between junctional SR proteins of frog and rabbit TC. After active Ca2+ preloading in the presence of pyrophosphate (Palade, P. (1987) J. Biol. Chem. 262, 6135-6141), caffeine and doxorubicin elicited Ca2+ release from either TC fraction but with much faster rates in frog TC than in rabbit TC (14 versus 3 mumol of Ca2+/min/mg of protein). The present results provide new evidence for the existence of marked differences in Ca2+ release properties between TC of amphibian and mammalian fast-twitch muscle. Higher Ca2+ binding capacity and faster release rates in frog TC might compensate for the comparably greater diffusion distance being covered by the released Ca2+ from the Z-line to the actomyosin cross-bridges in the A-I overlap region
Myosin heavy chain composition of muscle fibers in spinal muscular atrophy
No full textMuscle biopsies from 20 cases of spinal muscular atrophy (SMA), mostly diagnosed as Werdnig–Hoffmann (W–H) disease, were examined for myosin heavy chain (HC) composition. The fetal, fast, and slow heavy chains were characterized in the isolated muscle myosin, and in myosin of single, chemically skinned fibers, by electrophoresis in SDS‐6% polyacrylamide gels and by immunoblot techniques, using specific antibodies directed to each main type of myosin HC. The fiber distribution of myosin HC isozymes was further investigated on muscle cryostat sections by an indirect immunofluorescent technique. Fetal myosin HC was found to be expressed in a subpopulation of severely atrophic fibers, alone or together with the slow form of myosin HC. Triangulated fibers of intermediate size contained fetal and fast myosin or fast myosin alone. The hypertrophic fibers were characterized by the predominant expression of slow myosin HC; but in some of these fibers, also low amounts of HC fetal were found to be expressed. These findings are discussed in relation to developmental transitions of myosin heavy chains in human muscle. Copyright © 1989 John Wiley & Sons, Inc
Ca2+-dependent interaction of triadin with histidine-rich Ca2+-binding protein carboxyl-terminal region
No full textA direct binding of HRC (histidine-rich Ca(2+)-binding protein) to triadin, the main transmembrane protein of the junctional sarcoplasmic reticulum (SR) of skeletal muscle, seems well supported. Opinions are still divided, however, concerning the triadin domain involved, either the cytoplasmic or the lumenal domain, and the exact role played by Ca(2+), in the protein-to-protein interaction. Further support for colocalization of HRC with triadin cytoplasmic domain is provided here by experiments of mild tryptic digestion of tightly sealed TC vesicles. Accordingly, we show that HRC is preferentially phosphorylated by endogenous CaM K II, anchored to SR membrane on the cytoplasmic side, and not by lumenally located casein kinase 2. We demonstrate that HRC can be isolated as a complex with triadin, following equilibrium sucrose-density centrifugation in the presence of mM Ca(2+). Here, we characterized the COOH-terminal portion of rabbit HRC, expressed and purified as a fusion protein (HRC(569-852)), with respect to Ca(2+)-binding properties, and to the interaction with triadin on blots, as a function of the concentration of Ca(2+). Our results identify the polyglutamic stretch near the COOH terminus, as the Ca(2+)-binding site responsible, both for the acceleration in mobility of HRC on SDS-PAGE in the presence of millimolar concentrations of Ca(2+), and for the enhancement by high Ca(2+) of the interaction between HRC and triadin cytoplasmic segment. (c)2001 Elsevier Scienc
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