Webster K A
Department of Medicine, Stanford University School of Medicine, California 94305.
Mol Cell Biochem. 1987 Sep;77(1):19-28. doi: 10.1007/BF00230147.
Cytoplasmic beta-actin and five glycolytic enzyme cDNAs were isolated from a rat skeletal muscle cDNA library and together with a genomic clone of rat cytochrome c were used as probes to quantitate the respective RNA transcription rates in isolated nuclei run off transcription assays from stationary cells cultured under normal or 2% oxygen. The transcription rates of lactate dehydrogenase, pyruvate kinase, triosephosphate isomerase and aldolase increased by 2-5 fold during the 72 hr exposure to 2% oxygen. There was a small increase in actin RNA transcription while both cytochrome c and glyceraldehyde-3-phosphate dehydrogenase RNA transcription rates decreased. Since previous studies demonstrated an increase in steady state glyceraldehyde-3-phosphate dehydrogenase RNA during low O2 exposure it is concluded that the level of this RNA is regulated post transcriptionally whereas the other four glycolytic enzyme RNAs are regulated at least partially at the level of transcription by oxygen availability. The relative transcriptional rates of the RNAs in this study are related to their cellular RNA and protein concentrations.
从大鼠骨骼肌cDNA文库中分离出细胞质β-肌动蛋白和5种糖酵解酶的cDNA，并将其与大鼠细胞色素c的基因组克隆一起用作探针，以定量在正常氧气或2%氧气条件下培养的静止细胞的离体细胞核进行的转录延伸试验中各自的RNA转录速率。在暴露于2%氧气的72小时内，乳酸脱氢酶、丙酮酸激酶、磷酸丙糖异构酶和醛缩酶的转录速率增加了2至5倍。肌动蛋白RNA转录略有增加，而细胞色素c和甘油醛-3-磷酸脱氢酶RNA转录速率均下降。由于先前的研究表明在低氧暴露期间稳态甘油醛-3-磷酸脱氢酶RNA增加，因此得出结论，该RNA的水平在转录后受到调节，而其他四种糖酵解酶RNA至少部分在转录水平上受氧气可用性的调节。本研究中RNA的相对转录速率与其细胞RNA和蛋白质浓度相关。
