Inhibitory effects of the 3'-noncoding region derived from eukaryotic cDNA on the expression of the upstream...

The influence of 3'-noncoding region (ncr) of the cDNA derived from an eukaryotic mRNA on the preceding structure gene expression in E. coli was investigated using human immune interferon (GIF) and human tumor necrosis factor (TNF) cDNAs. Two sets of gene, with (ncr+) and without (ncr-) 3'-noncoding region, have been expressed in E. coli. In both cases, the level of ncr+ gene expression was five times lower than that of ncr- gene. When these ncrs were placed just downstream of various structure genes, the same effects were also observed. The RNA brot analysis showed that the ncr+ genes were transcribed into shorter and much less mRNA than ncr- genes. These results suggest that these ncrs accelerate the degradation of the mRNA by either causing the premature termination of transcription or the generation of sequence on the transcripts hypersensitive to E. coli endoribonucleases.