Enhanced production of insulin-like growth factor I fusion protein in Escherichia coli by coexpression of the down-regulated genes identified by transcriptome profiling.
The transcriptome profiles of recombinant Escherichia coli producing human insulin-like growth factor I fusion protein (IGF-I(f)) during the high-cell-density fed-batch culture were analyzed using DNA microarrays. The expression levels of 529 genes were significantly altered after induction. About 200 genes were significantly down-regulated during the production of IGF-I(f) after induction. Among these down-regulated genes, we rationally selected and coexpressed in E. coli producing IGF-I(f) the prsA gene (encoding a phosphoribosyl pyrophosphate synthetase) and the glpF gene (encoding a glycerol transporter), which are involved in an early key step in the biosynthetic pathway of nucleotides and amino acids (Trp and His) and the first step in glycerol utilization, respectively. As a result, the production of IGF-I(f) could be increased from 1.8 +/- 0.13 (+/- standard deviation) to 4.3 +/- 0.24 g/liter. The volumetric productivity was also increased from 0.36 +/- 0.027 to 0.82 +/- 0.048 g/liter/h. These results demonstrate that transcriptome profiling can provide invaluable information in designing engineered strains showing enhanced performance.
Choi
Jong Hyun
JH
Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering and BioProcess Engineering Research Center, Daejeon 305-701, Korea.
Lee
Sang Jun
SJ
Lee
Seok Jae
SJ
Lee
Sang Yup
SY
D020346:Aquaporins / Q000235:genetics; D001426:Bacterial Proteins; D015536:Down-Regulation; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis*; D008074:Lipoproteins / Q000235:genetics / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis*; D014158:Transcription, Genetic
D020346:Aquaporins; D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; C082160:prsA protein, bacteria; C078043:GlpF protein, E coli; D007334:Insulin-Like Growth Factor I