Format

Send to

Choose Destination
Genes Cells. 2001 Apr;6(4):375-88.

Induction of IRF-3/-7 kinase and NF-kappaB in response to double-stranded RNA and virus infection: common and unique pathways.

Author information

1
Department of Tumor Cell Biology, The Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8613, Japan.

Abstract

BACKGROUND:

Infection by virus or treatment with double-stranded RNA (dsRNA) results in the activation of transcription factors including IRF-3, IRF-7 and a pleiotropic regulator NF-kappaB by specific phosphorylation. These factors are important in triggering a cascade of antiviral responses. A protein kinase that is yet to be identified is responsible for the activation of these factors and plays a key role in the responses.

RESULTS:

The signal cascade was analysed using sensitive assays for the activation of IRF-3 and NF-kappaB, and various inhibitors. We found that the activation of IRF-3 and NF-kappaB by dsRNA or virus involves a process that is sensitive to Geldanamycin. Although the induction of NF-kappaB by dsRNA/virus and TNF-alpha involves common downstream pathways including IKK activation, the upstream, Geldanamycin-sensitive process was unique to the dsRNA/virus-induced signal. By an in vitro assay using cell extract, we found an inducible protein kinase activity with physiological specificity of IRF-3 phosphorylation. Furthermore, the same extract specifically phosphorylated IRF-7 in a similar manner.

CONCLUSIONS:

Double-stranded RNA or virus triggers a specific signal cascade that results in the activation of the IRF-3/-7 kinase we detected, which corresponds to the long-sought signalling machinery that is responsible for triggering the early phase of innate response. The signal branches to a common NF-kappaB activation cascade, thus resulting in the activation of a set of critical transcription factors for the response.

PMID:
11318879
[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center