A biological role of interferon-induced protein kinases.

Abstract

The experimental data reviewed in this paper suggest that the inhibition of viral polypeptide chain initiation in IFN-treated cells involves the phosphorylation of eIF-2 alpha and intermediate factors (65K and 67K ribosomal proteins) by an IFN-induced dsRNA-dependent ribosomal kinase. However, the discrimination mechanism between viral and host cell mRNAs at the translational level remain to be elucidated, because the mechanism is very complex. IFN will induce, for example, preferential digestion of viral mRNAs by 2',5'-oligo A activated endoribonuclease, will impair tRNAs and elongation factors for the protein synthesis, and will decrease methylation of viral mRNAs, and they are involved in the discrimination mechanism at translational level. The activation of membrane-associated kinase activity by IFNs is very interesting because its among the earliest recognized biochemical events induced in cells and may play an important role in IFN-induced host or cell defense. Further studies focusing on the biochemical roles of the membrane-associated kinase in IFN-treated cells may provide evidence for understanding the biochemical mechanism of cell activation by IFNs.