Interferon-stimulated response element (ISRE) -binding protein complex DRAF1 is activated in Sindbis virus (HR) -infected cells
Behr, M.; Schieferdecker, K.; Bühr, P.; Büter, M.; Petsophonsakul, W.; Sirirungsi, W.; Redmann-Müller, I.; Müller, U.; Prempracha, N.; Jungwirth, C.
Journal of Interferon and Cytokine Research the Official Journal of the International Society for Interferon and Cytokine Research 21(11): 981-990
2001
ISSN/ISBN: 1079-9907
PMID: 11747630
DOI: 10.1089/107999001753289596
Accession: 010866436
To elucidate the host cell defense mechanisms in response to Sindbis viral infection, we have started to characterize interferon (IFN)-stimulated response element (ISRE)-binding proteins activated in infected cells that are involved in the transcriptional induction of IFN type I-inducible genes. Using electromobility shift assays (EMSA), we detected several protein complexes with a human IFN-stimulated gene 15 (ISG15) ISRE in extracts from virus-infected L929 cells that were absent in extracts from uninfected cells. Comigration with Newcastle disease virus-activated ISRE-binding complexes, ISRE-binding specificity, supershift experiments, and conditions of formation indicate that the complexes activated by Sindbis viral infection in L929 cells correspond to DRAF1 and ISG factor 3 (ISGF3). Transfection of L929 cells with poly rI:rC induced only ISGF3. DRAF1 could be detected in Sindbis virus-infected mouse embryo fibroblasts derived from IFNR type I and type II KO mice. Viral RNA synthesis is required for activation of DRAF1.