Sarcoplasmic-reticulum biogenesis in contraction-inhibited skeletal-muscle cultures.
Sarcoplasmic-reticulum biogenesis in contraction-inhibited skeletal-muscle cultures.
复制标题
收缩抑制骨骼肌培养物中的肌浆网生物发生。
DOI：
10.1042/bj2820399
复制
发表时间：
1992
期刊：
影响因子：
--
通讯作者：
P. Holland
中科院分区：
文献类型：
--
作者：
J. Charuk;C. Guérin;P. Holland
我们之前已经表明，用河豚毒素（TTX）抑制培养的胚胎鸡骨骼肌纤维的自发收缩活性会导致肌浆网Ca（2+）转运速率降低和高能Ca（2+）-ATP酶磷酸酶中间体的稳态浓度降低[Charuk＆Holland（1983）实验。细胞研究。 144、143-157]。在本研究中，我们使用 Ca(2+)-ATP 酶单克隆抗体来表明收缩抑制的肌管积累的酶量减少。使用 Ca(2+)-ATPase 单克隆抗体进行的间接免疫荧光显微镜检查也揭示了收缩抑制的肌管中肌管系统的亚细胞组织紊乱。在分离活性Ca(2+)-泵膜部分之前，通过用[35S]蛋氨酸标记细胞来研究TTX麻痹的肌纤维中肌浆网蛋白的生物发生。经过 TTX 处理的肌肉培养物中，蛋白质周转率选择性增加。电泳分析和定量荧光检查证实，收缩抑制的肌管中Ca(2+)-ATP酶积累的减少与该蛋白质周转率的增加有关。目前的结果表明，肌浆网Ca(2+)-ATP酶的生物合成受骨骼肌纤维的收缩活性的调节。
We have previously shown that inhibition of the spontaneous contractile activity of cultured embryonic-chick skeletal-muscle fibres with tetrodotoxin (TTX) leads to decreased sarcoplasmic-reticulum Ca(2+)-transport rates and steady-state concentrations of the high-energy Ca(2+)-ATPase phosphoenzyme intermediate [Charuk & Holland (1983) Exp. Cell Res. 144, 143-157]. In the present study we used a monoclonal antibody to the Ca(2+)-ATPase to show that there is a decreased amount of enzyme accumulated by contraction-inhibited myotubes. Indirect immunofluorescence microscopy using the monoclonal antibody to the Ca(2+)-ATPase also revealed a disordered subcellular organization of the sarcotubular system in contraction-inhibited myotubes. The biogenesis of sarcoplasmic-reticulum proteins in TTX-paralysed myofibres was studied by labelling cells with [35S]methionine before isolation of the active Ca(2+)-pump membrane fraction. Protein turnover was selectively increased in that fraction from TTX-treated muscle cultures. Electrophoretic analysis and quantitative fluorography confirmed that decreased accumulation of the Ca(2+)-ATPase enzyme in contraction-inhibited myotubes was associated with increased turnover of this protein. The present results demonstrate that biogenesis of the sarcoplasmic-reticulum Ca(2+)-ATPase is regulated by the contractile activity of skeletal-muscle fibres.