COMPARATIVE-STUDY ON THE EFFECT OF SIGNAL PEPTIDE CODONS AND ARGININECODONS ON THE EXPRESSION OF HUMAN INTERFERON-ALPHA-1 GENE IN ESCHERICHIA-COLI

Human interferon-alpha 1 (HuIFN-alpha 1) gene containing signal peptid e codons is poorly expressed in bacteria, and this is explained by the presence of clusters of rare (AGG) arginine codons in its structure, In this study, we have constructed a series of modified HuIFN-alpha 1 genes to study the effect of both residual signal peptide codons and c lusters of AGG codons on gene expression in Escherichia coil cells, Ou r results showed that substitution of preferential for rare arginine c odons in two clusters did not affect the yield, whereas deletion of th e signal peptide codons led to a 10-fold increase in the yield of reco mbinant protein, To understand the mechanism of interference of gene s tructure on the expression of the HuIFN-alpha 1 gene in vivo, both the level and stability of HuIFN-alpha 1 mRNA were measured, The amount o f HuIFN mRNA increased almost five times on deletion of the signal pep tide codons from HuIFN-alpha 1 gene constructs (containing AGG cluster s or not), The stability of mRNA obtained from all gene constructs was shown to be the same (half-life of 60 +/- 5 sees), indicating that th e signal peptide codons interfere with both the efficiency of transcri ption of the HuIFN-alpha 1 gene and translation of its mRNA.