Roos Viktoria, Andersson Charlotte I J, Bülow Leif
Department of Pure and Applied Biochemistry, Center for Chemistry and Chemical Engineering, Lund University, P.O. Box 124, SE-22100 Lund, Sweden.
J Biotechnol. 2004 Oct 19;114(1-2):107-20. doi: 10.1016/j.jbiotec.2004.07.002.
In a recent investigation, expression of a double Vitreoscilla haemoglobin (two fused VHb molecules) in Escherichia coli grown in shake flasks resulted in higher final cell density and considerably higher levels of ribosomes and tRNA. In this study, we have investigated the E. coli transcriptome in cells expressing native VHb, double VHb and control cells lacking VHb by hybridising mRNA from the different constructs to high-density oligonucleotide arrays. Within the 95% confidence interval, 4 and 5% of all detected genes in native VHb cells were up- and down-regulated, respectively; in double VHb cells the corresponding numbers were 6 and 10%, respectively. Dividing the data into different functional groups revealed that genes involved in energy metabolism, central intermediary metabolism and cell processes were the most affected at the mRNA level. Particularly, the up-regulation of genes involved in translation and posttranslational modification observed in double VHb cells demonstrates a strong relationship between the regulation of ribosomal genes and the actual number of ribosomes.
在最近的一项研究中，在摇瓶中培养的大肠杆菌中表达双透明颤菌血红蛋白（两个融合的VHb分子），导致最终细胞密度更高，核糖体和tRNA水平也显著更高。在本研究中，我们通过将来自不同构建体的mRNA与高密度寡核苷酸阵列杂交，研究了表达天然VHb、双VHb的细胞以及缺乏VHb的对照细胞中的大肠杆菌转录组。在95%置信区间内，天然VHb细胞中所有检测到的基因分别有4%和5%上调和下调；在双VHb细胞中，相应的数字分别为6%和10%。将数据分为不同的功能组后发现，参与能量代谢、中心中间代谢和细胞过程的基因在mRNA水平上受到的影响最大。特别是，在双VHb细胞中观察到的参与翻译和翻译后修饰的基因上调，表明核糖体基因的调控与核糖体的实际数量之间存在密切关系。
