Molecular interactions between interferon consensus sequence binding protein and members of the interferon regulatory factor family.
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-alpha-stimulated gene factor 3 gamma (ISGF3 gamma). 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-alpha-stimulated gene factor 3 gamma to the ISRE. Through these interactions ICSBP is likely to exert complex modulatory functions in the regulation of IFN-stimulated genes.
Bovolenta
C
C
Laboratory of Molecular Growth Regulation, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
Driggers
P H
PH
Marks
M S
MS
Medin
J A
JA
Politis
A D
AD
Vogel
S N
SN
Levy
D E
DE
Sakaguchi
K
K
Appella
E
E
Coligan
J E
JE
D001483:Base Sequence; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D016384:Consensus Sequence; D004247:DNA; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D050835:Interferon Regulatory Factors; D050832:Interferon-Stimulated Gene Factor 3; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit; D008969:Molecular Sequence Data; D010750:Phosphoproteins / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D012097:Repressor Proteins; D014157:Transcription Factors / Q000378:metabolism; D000099185:Interferon Regulatory Factor-8
D002352:Carrier Proteins; D004247:DNA; D004268:DNA-Binding Proteins; D050856:Interferon Regulatory Factor-1; D050836:Interferon Regulatory Factor-2; D050835:Interferon Regulatory Factors; D050832:Interferon-Stimulated Gene Factor 3; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit; D010750:Phosphoproteins; D012097:Repressor Proteins; D014157:Transcription Factors; D000099185:Interferon Regulatory Factor-8; C494257:IRF1 protein, human; C494229:IRF2 protein, human; C494227:IRF9 protein, human