Webster K A, Gunning P, Hardeman E, Wallace D C, Kedes L
Department of Biochemistry, School of Medicine, University of Southern California, Los Angeles 90033.
J Cell Physiol. 1990 Mar;142(3):566-73. doi: 10.1002/jcp.1041420316.
Changes in the mRNA levels during mammalian myogenesis were compared for seven polypeptides of mitochondrial respiration (the mitochondrial DNA-encoded cytochrome oxidase subunit III, ATP synthase subunit 6, NADH dehydrogenase subunits 1 and 2, and 16S ribosomal RNA; the nuclear encoded ATP synthase beta subunit and the adenine nucleotide translocase) and three polypeptides of glycolysis (glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, and triose-phosphate isomerase). Progressive changes during the conversion from myoblasts to myotubes were monitored under both atmospheric oxygen (normoxic) and hypoxic environments. Northern analyses revealed coordinate, biphasic, and reciprocal expression of the respiratory and glycolytic mRNAs during myogenesis. In normoxic cells the mitochondrial respiratory enzymes were highest in myoblasts, declined 3- to 5-fold during commitment and exist from the cell cycle, and increased progressively as the myotubes matured. By contrast, the glycolytic enzyme mRNAs rose 3- to 6-fold on commitment and then progressively declined. When partially differentiated myotubes were switched to hypoxic conditions, the glycolytic enzyme mRNAs increased and the respiratory mRNAs declined. Hence, the developmental regulation of muscle bioenergetic metabolism appears to be regulated at the pretranslational level and is modulated by oxygen tension.
比较了哺乳动物肌生成过程中7种线粒体呼吸相关多肽（线粒体DNA编码的细胞色素氧化酶亚基III、ATP合酶亚基6、NADH脱氢酶亚基1和2以及16S核糖体RNA；核编码的ATP合酶β亚基和腺嘌呤核苷酸转位酶）和3种糖酵解相关多肽（甘油醛-3-磷酸脱氢酶、丙酮酸激酶和磷酸丙糖异构酶）的mRNA水平变化。在大气氧（常氧）和低氧环境下，监测了成肌细胞向肌管转化过程中的渐进性变化。Northern分析显示，在肌生成过程中，呼吸和糖酵解mRNA存在协同、双相和相互的表达。在常氧细胞中，线粒体呼吸酶在成肌细胞中最高，在分化和退出细胞周期过程中下降3至5倍，并随着肌管成熟而逐渐增加。相比之下，糖酵解酶mRNA在分化时上升3至6倍，然后逐渐下降。当部分分化的肌管切换到低氧条件时，糖酵解酶mRNA增加，呼吸mRNA下降。因此，肌肉生物能量代谢的发育调控似乎在翻译前水平受到调节，并受氧张力的影响。
