Interferon (IFN) consensus sequence binding protein (ICSBP) is a transcription factor expressed mostly in the cells of the immune system. ICSBP belongs to the IFN regulatory factor (IRF) family, which also includes IRF-1, IRF-2, and the IFN-α-stimulated gene factor 3γ (ISGF3γ). We show here that ICSBP forms a complex with IRF-1 or IRF-2 both in vivo and in vitro and, in the presence or absence of the target DNA, with the IFN-stimulated response element (ISRE). Further, electrophoretic mobility shift assays show that this interaction greatly enhances the otherwise very low binding affinity of ICSBP to the ISRE. We show, on the other hand, that ICSBP inhibits binding of the IFN-α-stimulated gene factor 3γ to the ISRE. Through these interactions ICSBP is likely to exert complex modulatory functions in the regulation of IFN-stimulated genes.
|Original language||English (US)|
|Number of pages||5|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - May 24 1994|
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