Expression of avian Ca2+-ATPase in cultured mouse myogenic cells

1989 ◽  
Vol 9 (5) ◽  
pp. 1978-1986
Author(s):  
N J Karin ◽  
Z Kaprielian ◽  
D M Fambrough

cDNA encoding Ca2+-ATPase was cloned from a chicken skeletal muscle library. The cDNA (termed FCa) comprised 3,239 base pairs, including an open reading frame encoding 994 amino acids which showed the highest degree of homology with the adult rabbit fast-twitch Ca2+-ATPase isoform (C. J. Brandl, S. de Leon, D. R. Martin, and D. H. MacLennan, J. Biol. Chem. 262:3768-3774, 1987). Radiolabeled FCa hybridized to a 3.2-kilobase transcript in chicken skeletal muscle RNA but not to cardiac muscle RNA, which confirmed its identity as encoding the fast Ca2+-ATPase isoenzyme. FCa was transfected into the mouse myogenic line C2C12, from which a protein of 100 kilodaltons was immunopurified by using a monoclonal antibody specific for the avian fast Ca2+-ATPase. Immunofluorescence microscopy of a line (designated C2FCa2) stably expressing the avian Ca2+-ATPase localized the protein to the nuclear envelope and a population of cytoplasmic vesicles. A similar pattern was observed when C2FCa2 cells were stained with DiOC6(3), a cyanine dye that labels endoplasmic reticulum and mitochondria (M. Terasaki, J. Song, J. R. Wong, M. J. Weiss, and L. B. Chen, Cell 38:101-108, 1984). We conclude that the avian Ca2+-ATPase fast isoform is expressed and correctly targeted to the endoplasmic reticulum in mouse C2C12 cells.

1989 ◽  
Vol 9 (5) ◽  
pp. 1978-1986 ◽  
Author(s):  
N J Karin ◽  
Z Kaprielian ◽  
D M Fambrough

cDNA encoding Ca2+-ATPase was cloned from a chicken skeletal muscle library. The cDNA (termed FCa) comprised 3,239 base pairs, including an open reading frame encoding 994 amino acids which showed the highest degree of homology with the adult rabbit fast-twitch Ca2+-ATPase isoform (C. J. Brandl, S. de Leon, D. R. Martin, and D. H. MacLennan, J. Biol. Chem. 262:3768-3774, 1987). Radiolabeled FCa hybridized to a 3.2-kilobase transcript in chicken skeletal muscle RNA but not to cardiac muscle RNA, which confirmed its identity as encoding the fast Ca2+-ATPase isoenzyme. FCa was transfected into the mouse myogenic line C2C12, from which a protein of 100 kilodaltons was immunopurified by using a monoclonal antibody specific for the avian fast Ca2+-ATPase. Immunofluorescence microscopy of a line (designated C2FCa2) stably expressing the avian Ca2+-ATPase localized the protein to the nuclear envelope and a population of cytoplasmic vesicles. A similar pattern was observed when C2FCa2 cells were stained with DiOC6(3), a cyanine dye that labels endoplasmic reticulum and mitochondria (M. Terasaki, J. Song, J. R. Wong, M. J. Weiss, and L. B. Chen, Cell 38:101-108, 1984). We conclude that the avian Ca2+-ATPase fast isoform is expressed and correctly targeted to the endoplasmic reticulum in mouse C2C12 cells.


2018 ◽  
Vol 315 (5) ◽  
pp. C609-C622 ◽  
Author(s):  
Avisek Majumder ◽  
Mahavir Singh ◽  
Jyotirmaya Behera ◽  
Nicholas T. Theilen ◽  
Akash K. George ◽  
...  

Although hyperhomocysteinemia (HHcy) occurs because of the deficiency in cystathionine-β-synthase (CBS) causing skeletal muscle dysfunction, it is still unclear whether this effect is mediated through oxidative stress, endoplasmic reticulum (ER) stress, or both. Nevertheless, there is no treatment option available to improve HHcy-mediated muscle injury. Hydrogen sulfide (H2S) is an antioxidant compound, and patients with CBS mutation do not produce H2S. In this study, we hypothesized that H2S mitigates HHcy-induced redox imbalance/ER stress during skeletal muscle atrophy via JNK phosphorylation. We used CBS+/−mice to study HHcy-mediated muscle atrophy, and treated them with sodium hydrogen sulfide (NaHS; an H2S donor). Proteins and mRNAs were examined by Western blots and quantitative PCR. Proinflammatory cytokines were also measured. Muscle mass and strength were studied via fatigue susceptibility test. Our data revealed that HHcy was detrimental to skeletal mass, particularly gastrocnemius and quadriceps muscle weight. We noticed that oxidative stress was reversed by NaHS in homocysteine (Hcy)-treated C2C12 cells. Interestingly, ER stress markers (GRP78, ATF6, pIRE1α, and pJNK) were elevated in vivo and in vitro, and NaHS mitigated these effects. Additionally, we observed that JNK phosphorylation was upregulated in C2C12 after Hcy treatment, but NaHS could not reduce this effect. Furthermore, inflammatory cytokines IL-6 and TNF-α were higher in plasma from CBS as compared with wild-type mice. FOXO1-mediated Atrogin-1 and MuRF-1 upregulation were attenuated by NaHS. Functional studies revealed that NaHS administration improved muscle fatigability in CBS+/−mice. In conclusion, our work provides evidence that NaHS is beneficial in mitigating HHcy-mediated skeletal injury incited by oxidative/ER stress responses.


1992 ◽  
Vol 262 (3) ◽  
pp. C614-C620 ◽  
Author(s):  
M. Arai ◽  
K. Otsu ◽  
D. H. MacLennan ◽  
M. Periasamy

The expression of major sarcoplasmic reticulum proteins during cardiac and fast-twitch skeletal muscle development was examined using gene-specific probes. Through the use of S1 nuclease mapping, Northern blot, and RNA slot-blot analysis, sarcoplasmic reticulum proteins were shown to exhibit both narrow tissue specificity and plasticity in their expression during muscle development. In fast-twitch skeletal muscle, the cardiac/slow-twitch isoforms of Ca(2+)-ATPase and calsequestrin were detected at high levels in fetal stages but were gradually replaced by fast-twitch isoforms in adult muscle. In contrast, cardiac muscle expressed exclusively cardiac/slow-twitch isoforms of Ca(2+)-ATPase and calsequestrin at all stages. Both fast-twitch and slow-twitch skeletal muscle expressed the same skeletal muscle ryanodine receptor isoform, whereas cardiac muscle expressed a cardiac isoform. Phospholamban expression was restricted to cardiac and slow-twitch skeletal muscle and did not appear in developing fast-twitch skeletal muscle. During in vitro myogenesis of C2C12 cells, the mRNA transcripts encoding sarcoplasmic reticulum proteins were found to be coordinately induced in synchrony with that of contractile protein mRNA. The myogenic factor "myogenin" induced sarcoplasmic reticulum gene transcripts along with contractile protein mRNAs in nonmyogenic cells. These data suggest that the induction of both sarcoplasmic reticulum and contractile protein gene families is under the control of a common myogenic differentiation program.


1989 ◽  
Vol 257 (1) ◽  
pp. 117-123 ◽  
Author(s):  
F Wuytack ◽  
Y Kanmura ◽  
J A Eggermont ◽  
L Raeymaekers ◽  
J Verbist ◽  
...  

Smooth muscle expresses in its endoplasmic reticulum an isoform of the Ca2+-transport ATPase that is very similar to or identical with that of the cardiac-muscle/slow-twitch skeletal-muscle form. However, this enzyme differs from that found in fast-twitch skeletal muscle. This conclusion is based on two independent sets of observations, namely immunological observations and phosphorylation experiments. Immunoblot experiments show that two different antibody preparations against the Ca2+-transport ATPase of cardiac-muscle sarcoplasmic reticulum also recognize the endoplasmic-reticulum/sarcoplasmic-reticulum enzyme of the smooth muscle and the slow-twitch skeletal muscle whereas they bind very weakly or not at all to the sarcoplasmic-reticulum Ca2+-transport ATPase of the fast-twitch skeletal muscle. Conversely antibodies directed against the fast-twitch skeletal-muscle isoform of the sarcoplasmic-reticulum Ca2+-transport ATPase do not bind to the cardiac-muscle, smooth-muscle or slow-twitch skeletal-muscle enzymes. The phosphorylated tryptic fragments A and A1 of the sarcoplasmic-reticulum Ca2+-transport ATPases have the same apparent Mr values in cardiac muscle, slow-twitch skeletal muscle and smooth muscle, whereas the corresponding fragments in fast-twitch skeletal muscle have lower apparent Mr values. This analytical procedure is a new and easy technique for discrimination between the isoforms of endoplasmic-reticulum/sarcoplasmic-reticulum Ca2+-transport ATPases.


2006 ◽  
Vol 290 (2) ◽  
pp. C626-C637 ◽  
Author(s):  
Aikaterini Kontrogianni-Konstantopoulos ◽  
Dawn H. Catino ◽  
John C. Strong ◽  
Robert J. Bloch

We studied the distribution of the giant sarcomeric protein obscurin during de novo myofibrillogenesis in C2C12 myotubes to learn when it is integrated into developing sarcomeres. Obscurin becomes organized first at the developing M band and later at the mature Z disk. Primordial M bands consisting of obscurin, myomesin, and M band epitopes of titin assemble before adult fast-twitch sarcomeric myosin is organized periodically and nearly concurrently with primitive Z disks, which are composed of α-actinin and Z disk epitopes of titin. Z disks and M bands can assemble independently at spatially distant sites. As sarcomerogenesis proceeds, these structures interdigitate to produce a more mature organization. Fast-twitch muscle myosin accumulates in the myoplasm and assembles into A bands only after Z disks and M bands assume their typical interdigitated striations. The periodicities of M bands remain constant at ∼1.8 μm throughout sarcomerogenesis, whereas distances between Z disks increase from ∼1.1 μm in early sarcomeres to ∼1.8 μm in more mature structures. Our findings indicate for the first time that primitive M bands self-assemble independently of Z disks, that obscurin is a component of these primitive M bands in skeletal muscle cells, and that A bands assemble only after M bands and Z disks integrate into maturing sarcomeres.


1986 ◽  
Vol 235 (1) ◽  
pp. 67-73 ◽  
Author(s):  
E Leberer ◽  
D Pette

Parvalbumin was purified from rabbit fast skeletal muscle and used to raise antibodies in sheep. Subsequently, a sensitive ‘sandwich’ enzyme-linked immunoadsorbent assay permitted quantification of parvalbumin in homogenates of embryonic, maturing, innervated, denervated and chronically stimulated skeletal muscles of the rabbit. High concentrations of parvalbumin were detected in various adult fast-twitch muscles of the rabbit (700-1200 micrograms/g of muscle), whereas slow-twitch muscles contained negligible concentrations (3-5 micrograms/g of muscle). Parvalbumin was not detectable in embryonic-rabbit muscles (21, 25, 28 days of gestation), either presumptive fast- or slow-twitch. However, parvalbumin concentrations did increase during postnatal development in presumptive fast-twitch muscles. Thus the onset of parvalbumin synthesis appears to be correlated with the neonatal-to-adult transition of motor-neuron activity [Navarrete & Vrbová (1983) Dev. Brain Res. 8, 11-19]. The increase of parvalbumin in maturing, presumptive fast-twitch muscle was suppressed by denervation. In the adult rabbit, denervation of the tibialis anterior muscle caused a reduction of parvalbumin to a level normally found in slow-twitch muscles. In contrast, the already low levels of parvalbumin in maturing and adult slow-twitch soleus muscle were unaffected by denervation. Chronic low-frequency stimulation of adult fast-twitch muscle resulted in a rapid reduction of parvalbumin to a level normally found in slow-twitch muscle. These data support the hypothesis that the expression of parvalbumin is under positive control of fast-type motor-neuron activity.


1996 ◽  
Vol 270 (1) ◽  
pp. C298-C305 ◽  
Author(s):  
M. M. Briggs ◽  
F. Schachat

NH2-terminal isoforms of fast troponin T (TnT) are generated by alternative splicing of fast TnT RNA transcripts. Significantly different estimates for the number of isoforms have been obtained by nucleic acid and protein chemical studies. To resolve this controversy and to determine whether specific 5'-splicing patterns correlate with fiber phenotype, we generated representative populations of 5'-TnT cDNAs from the TnT mRNAs expressed in a set of physiologically and anatomically diverse skeletal muscles. Sequencing and restriction enzyme analyses revealed a total of nine cDNAs that encode the six adult and three perinatal NH2-terminal TnT variants previously identified. Three major 5'-splicing pathways (the TnT1f, TnT2f, and TnT3f patterns) account for more than 90% of the TnT mRNAs and proteins in adult rabbit skeletal muscle. Comparative studies in rats, mice, and humans show that these splicing patterns are conserved and that fast-twitch fibers that are primarily glycolytic utilize the TnT1f and TnT2f patterns preferentially, whereas fast-twitch fibers that are primarily oxidative use the TnT1f and TnT3f patterns preferentially.


1991 ◽  
Vol 260 (6) ◽  
pp. C1325-C1331 ◽  
Author(s):  
D. A. Essig ◽  
D. L. Devol ◽  
P. J. Bechtel ◽  
T. J. Trannel

Chronic stretch of the chicken fast-twitch patagialis muscle increases the rate of growth and percentage of fast-twitch oxidative fibers. We have analyzed the effects of stretch on the expression of two previously identified “embryonic” myosin heavy chain (MHC) mRNAs (p251 and p110). Both MHC mRNAs were expressed in the patagialis at their highest levels in the embryo and 1 wk after hatching. During posthatch development (7-52 wk), the p110 mRNA was expressed in only trace quantities while the p251 mRNA was not detectable. After 2 wk of stretch of the patagialis in 7- or 38-wk-old birds, the p110 mRNA was increased to levels similar to that found in patagialis of newly hatched chicks, whereas expression of the p251 transcript was not affected. The existence of two other MHC mRNAs homologous to the p110 mRNA was suggested by the S1 mapping analysis, one of which was expressed at dramatically reduced levels in the stretched patagialis. It is concluded that stretch can cause selective alterations in the expression of developmentally regulated MHC isoforms in chicken fast-twitch muscle.


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