IRF-8/ICSBP and IRF-1 are IRF family members whose expression is induced in response to IFN-gamma in macrophages. IL-12 is a cytokine produced in macrophages that plays a critical role in host defense. IFN-gamma and bacterial lipopolysaccharide (LPS) induce IL-12p40 transcription, which is necessary for the production of IL-12. We have previously shown that IL-12p40 expression is impaired in ICSBP-deficient mice and that transfection of ICSBP together with IRF-1 can activate IL-12p40 expression in mouse macrophage cells. To further study the role of ICSBP and IRF-1, we investigated murine IL-12p40 promoter activity in the macrophage cell line RAW 264.7. We show here that co-transfection of ICSBP and IRF-1 synergistically stimulates IL-12 promoter activity to a level comparable to that induced by IFN-gamma/LPS. Mutation of the Ets or NFkappaB site previously shown to be important for IL-12p40 transcription did not abolish the activation by ICSBP and IRF-1. However, mutation of the ISRE-like site found downstream from the NFkappaB and C/EBP sites abrogated the activation by ICSBP and IRF-1. Together, these results indicate that ICSBP and IRF-1 cooperatively stimulate murine IL-12 transcription through a novel regulatory element in the murine promoter.
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http://dx.doi.org/10.1016/s0014-5793(02)03556-1 | DOI Listing |
Dev Comp Immunol
February 2018
National Engineering Research Center of Marine Facilities Aquaculture, College of Marine Science, Zhejiang Ocean University, Zhoushan 316004, China. Electronic address:
In this study, we sequenced and characterized an interferon-stimulated gene Viperin homologue, LcViperin, from large yellow croaker (Larimichthys crocea). The LcViperin encodes 354 amino acids and contains an N-terminal amphipathic α-helix domain, a radical S-adenosyl-l-methionine (SAM) domain and a highly conserved C-terminal domain. The analyses of LcViperin promoter region revealed nine kinds of putative transcriptional factor binding sites, including five putative ICSBP (IRF-8) binding sites and one putative IRF-1 binding site, indicating that the expression of LcViperin might be induced by the type I IFN response.
View Article and Find Full Text PDFBiomed Res Int
July 2016
School of Computer Science and Technology, Harbin Institute of Technology, Harbin, Heilongjiang 150001, China.
Transcription factors are proteins that bind to DNA sequences to regulate gene transcription. The transcription factor binding sites are short DNA sequences (5-20 bp long) specifically bound by one or more transcription factors. The identification of transcription factor binding sites and prediction of their function continue to be challenging problems in computational biology.
View Article and Find Full Text PDFFish Shellfish Immunol
April 2014
Department of Marine Life Sciences, School of Marine Biomedical Sciences, Jeju National University, Jeju Self-Governing Province 690-756, Republic of Korea. Electronic address:
The interferon regulatory factor 5 (IRF5) is a key mediator of the Toll-like receptor (TLR)7 and TLR8 signaling pathways. In this study, we describe the identification of IRF5 (Rb-IRF5) from rock bream fish (Oplegnathus fasciatus) and its characteristics features at the genomic and expression levels. The full-length Rb-IRF5 sequence was identified from a cDNA library and its genomic sequence was obtained by screening and sequencing of a bacterial artificial chromosome (BAC) genomic DNA library of rock bream.
View Article and Find Full Text PDFJ Biol Chem
July 2010
Division of Immunobiology, Department of Internal Medicine, Saint Louis University School of Medicine, St Louis, Missouri 63104, USA.
Interferon regulatory factor (IRF) family members, especially interferon regulatory factor-1 (IRF-1) and interferon regulatory factor-8 (IRF-8 or ICSBP), play important roles in interferon signaling in a wide range of host responses to infection and tumor growth. Interleukin-27 (IL-27), as a member of the IL-12 cytokine family, not only acts as a proinflammatory cytokine that regulates the differentiation of naive T helper cells but also possesses anti-inflammatory properties. IL-27 consists of EBI3 (Epstein-Barr virus-induced gene 3) and p28 subunits.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2008
Department of Molecular Biology, Dankook University, Gyeonggi-do 448-701, Republic of Korea.
To characterize the regulatory mechanism of the interferon regulatory factor (IRF) family, we performed yeast two-hybrid screening with IRF-2 and isolated the small ubiquitin-related modifier (SUMO)-conjugating enzyme Ubc9, which also interacts with other IRF family members IRF-1 and ICSBP. Subsequent assays indicated that among the IRF family members, only IRF-1 interacts with SUMO-1 through its transcriptional activation domain. The interaction between IRF-1 and SUMO-1 was confirmed in vitro by GST pull-down assays and in vivo by co-localization assays.
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