Synthesis of fusion and mature murine alpha interferons in Escherichia coli

Impaired antiviral response and alpha/beta interferon induction in mice lacking beta interferon

We have generated mice lacking the gene for beta interferon and report that they are highly susceptible to vaccinia virus infection. Furthermore, in cultured embryo fibroblasts, viral induction of alpha interferon and of 2-5A synthetase genes is impaired. We also show that beta interferon does not prime its own expression.

Conserved amino acid residues arginine 33 and tyrosine 123 are critical for the antiviral activity of murine interferon-alpha 1

Analogues of murine interferon-alpha 1 were produced by site directed mutagenesis and expressed in vitro. Replacement of the conserved residue arginine 33 by glutamic acid resulted in an interferon with no detectable antiviral activity. Substitution of tyrosine residue 123 shows dramatic reductions in the antiviral activity. These analogues demonstrate the importance of the conserved residues arginine 33 and tyrosine 123 in maintaining the antiviral activity of murine interferon-alpha 1.

Structure-function analysis of murine interferon-alpha: antiviral properties of novel hybrid interferons

As described earlier the protein products of the murine interferon (IFN) genes MuIFN-alpha 1, -alpha 2, and -alpha 4 differ in their antiviral activity on hamster (CHO) and mouse (L929) cells. For structure-function analysis, hybrids were prepared between the three genes using common restriction enzyme sites. Natural and hybrid genes were transiently expressed in monkey COS cells. Under the conditions used IFN constituted 20-30% of the total amount of secreted proteins. Using a panel of hybrids either between alpha 1 and alpha 2 or between alpha 1, alpha 2, and alpha 4, the amino-terminal region of the protein, from amino acids 10 to 58, was found to determine its antiviral activity on hamster cells. On mouse cells, the antiviral activities of hybrids between alpha 4 and either alpha 1 or alpha 2 were compared. The high activity of alpha 4 (five to ten times that of alpha 1 or alpha 2) was not transmitted to hybrids having the amino-terminal part of alpha 4, but coincided with the presence of the alpha 4 carboxy-terminal region in all but one hybrid construct. The deletion of five amino acids (positions 103-107) located in this region of alpha 4 did not affect antiviral activity when introduced into MuIFN-alpha 2 and a MuIFN-alpha 42 hybrid by site-directed mutagenesis.