Cooperation of STAT-1 and IRF-1 in interferon-gamma-induced transcription of the gp91(phox) gene.
Interferon (IFN)-gamma induces the expression of the gp91(phox) gene both during myeloid differentiation and also in mature phagocytes through several cis-elements and their binding proteins. To find new cis-elements for this induction, transient expression assays were performed using a reporter gene driven by serially truncated gp91(phox) promoters in U937 cells. The results suggest that a critical cis-element for induction exists in the region from bp -115 to -96 of the promoter. Site-directed mutagenesis showed that a gamma-activated sequence (GAS) element at bp -100 (-100GAS) of the gp91(phox) promoter plays a pivotal role for the IFN-gamma-dependent activity of the bp -115 to +12 region of the gp91(phox) promoter. Electrophoretic mobility shift assays using several GAS competitors and specific antibodies indicated that phosphorylated STAT-1alpha specifically binds to the -100GAS. Site-directed mutagenesis showed that an interferon-stimulated response element (ISRE) at bp -88 (-88ISRE) mediates the induction of the gene by IFN-gamma in cooperation with -100GAS. Electrophoretic mobility shift assay showed that IRF-1 dominantly binds to -88ISRE in an IFN-gamma-dependent fashion. These results demonstrate a new mechanism for IFN-gamma-induced transcription of the gp91(phox) gene by the cooperation of STAT-1alpha and IRF-1 binding to -100GAS and -88ISRE, respectively.
Kumatori
Atsushi
A
Department of Host-defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Sakamoto 1-12-4, Nagasaki 852-8523, Japan. kumatori@net.nagasaki-u.ac.jp
Yang
Dan
D
Suzuki
Shoichi
S
Nakamura
Michio
M
D000818:Animals; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D050856:Interferon Regulatory Factor-1; D007371:Interferon-gamma / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000235:genetics*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D020218:Response Elements; D050794:STAT1 Transcription Factor; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic / Q000187:drug effects*; D020298:U937 Cells
D004268:DNA-Binding Proteins; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; C494259:Irf1 protein, rat; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; C494081:Stat1 protein, rat; D015534:Trans-Activators; D007371:Interferon-gamma; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases