Combinatorial association and abundance of components of interferon-stimulated gene factor 3 dictate the selectivity of interferon responses.

Abstract

Genes containing the interferon-stimulated response element (ISRE)

Expression regulation of zebrafish interferon regulatory factor 9 by promoter analysis

“…In IRF9-dificent mouse cells, activation of ISGs and establishment of host antiviral state by IFNa or IFNc are both severely impaired, and ISRE-binding activities induced by both IFNs are absent, indicating that IRF9 is essential for type I IFN as well as type II IFN response (Kimura et al, 1996). Involvement of IRF9 in IFNc signaling is supported by the finding that IFNc stimulates the formation of an ISGF3-like factor, possibly consisting of IRF9 and STAT1, to bind the ISRE motifs of ISGs (Bluyssen et al, 1995). IRF9 is also known as ISGF3c, since it is first characterized as one IFNc-inducible component of ISGF3 (Levy et al, 1989).…”

Differentiation of Monocytes to Macrophages Switches theMycobacterium tuberculosisEffect on HIV-1 Replication from Stimulation to Inhibition: Modulation of Interferon Response and CCAAT/Enhancer Binding Protein β Expression

“…STAT-1 homodimers bind to a IFN-␥-activated site (GAS) and activate an overlapping, but distinct, set of genes (36,37). STAT-1 homodimers can also interact with IRF-9 and bind ISRE-type enhancer elements (36). It has become clear that additional regulation, often cell type specific, is superimposed on this framework (33,37).…”

“…ISGF-3 is a heterotrimer of STAT-1, STAT-2, and IFN regulatory factor (IRF)-9 (previously called p48 or ISGF-3␥) that rapidly translocates to the nucleus and binds promoter sequences, named IFN-stimulated response elements (ISRE) to activate gene expression. STAT-1 homodimers bind to a IFN-␥-activated site (GAS) and activate an overlapping, but distinct, set of genes (36,37). STAT-1 homodimers can also interact with IRF-9 and bind ISRE-type enhancer elements (36).…”

“…Bluescript KS Ϫ (Stratagene, La Jolla, CA) and RcCMV (Invitrogen, San Diego, CA) were used as negative controls and to determine background signal. The IRF-9 cDNA clone has been previously described (36). The STAT-1 and STAT-2 cDNA clones were previously called p91 and p113, respectively (51).…”

“…Nuclear extracts were prepared by Nonidet P-40 lysis and incubation of recovered nuclei in high salt buffer, as previously described (50). Transfection of an IRF-9 expression construct into 293T cells was performed as previously described (36) to obtain recombinant IRF-9 in Nonidet P-40 whole cell extracts prepared 2 days posttransfection. Production of recombinant IRF-9 was assessed by immunoblot and EMSA.…”