FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2017190892> ?p ?o ?g. }

• W2017190892 endingPage "30689" @default.
• W2017190892 startingPage "30686" @default.
• W2017190892 abstract "Genotoxic stress triggers signal transduction pathways that mediate either the protection or apoptosis of affected cells. The interferon regulatory factors (IRFs) are involved in a wide range of host defense mechanisms against environmental stresses. Treatment with DNA-damaging agents, including doxorubicin and UV radiation, caused phosphorylation of the IRF3 transcription factor. Phosphorylation of IRF3 induced its interaction with the transcriptional co-activator cAMP-response element binding protein-binding protein. Furthermore, genotoxic stress-induced phosphorylation of IRF3 resulted in its movement from the cytoplasm to the nucleus, where it activated transcription from its binding site. These observations suggest that IRF3 plays a role in the defensive responses induced by genotoxic stress. Genotoxic stress triggers signal transduction pathways that mediate either the protection or apoptosis of affected cells. The interferon regulatory factors (IRFs) are involved in a wide range of host defense mechanisms against environmental stresses. Treatment with DNA-damaging agents, including doxorubicin and UV radiation, caused phosphorylation of the IRF3 transcription factor. Phosphorylation of IRF3 induced its interaction with the transcriptional co-activator cAMP-response element binding protein-binding protein. Furthermore, genotoxic stress-induced phosphorylation of IRF3 resulted in its movement from the cytoplasm to the nucleus, where it activated transcription from its binding site. These observations suggest that IRF3 plays a role in the defensive responses induced by genotoxic stress. The family of interferon regulatory factors (IRFs) 1The abbreviations used are:IRFinterferon regulatory factorCATchloramphenicol acetyltransferaseCBPcAMP-response element binding protein-binding proteinGFPgreen fluorescent proteinHAhemagglutininPAGEpolyacrylamide gel electrophoresis1The abbreviations used are:IRFinterferon regulatory factorCATchloramphenicol acetyltransferaseCBPcAMP-response element binding protein-binding proteinGFPgreen fluorescent proteinHAhemagglutininPAGEpolyacrylamide gel electrophoresis is involved in a wide range of host defense mechanisms (reviewed in Refs. 1Nguyen H. Hiscott J. Pitha P.M. Cytokine Growth Factor Rev. 1997; 8: 293-312Crossref PubMed Scopus (416) Google Scholar and 2Taniguchi T. J. Cell. Physiol. 1997; 173: 128-130Crossref PubMed Scopus (48) Google Scholar). IRF proteins stimulate the expression of many genes with antiviral, antiproliferative, apoptotic, and immunomodulatory functions. This family of proteins now includes nine members: IRF1, IRF2, IRF3, IRF4, IRF5, IRF6, IRF7, interferon consensus sequence-binding protein, and interferon-stimulated gene factor 3γ (ISGF3γ). interferon regulatory factor chloramphenicol acetyltransferase cAMP-response element binding protein-binding protein green fluorescent protein hemagglutinin polyacrylamide gel electrophoresis interferon regulatory factor chloramphenicol acetyltransferase cAMP-response element binding protein-binding protein green fluorescent protein hemagglutinin polyacrylamide gel electrophoresis Among the IRF family members, IRF3 is of particular interest because its activation appears to have a direct role in the induction of defensive responses. Recently, viral infection was shown to induce the phosphorylation of IRF3 without any alteration in its protein level (3Juang Y. Lowther W. Kellum M. Au W. Lin R. Hiscott J. Pitha P.M. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 9837-9842Crossref PubMed Scopus (236) Google Scholar, 4Lin R. Heylbroeck C. Pitha P.M. Hiscott J. Mol. Cell. Biol. 1998; 18: 2986-2996Crossref PubMed Scopus (742) Google Scholar, 5Navarro L. Mowen K. Rodems S. Weaver B. Reich N. Spector D. David M. Mol. Cell. Biol. 1998; 18: 3796-3802Crossref PubMed Scopus (133) Google Scholar, 6Sato M. Tanaka N. Hata N. Oda E. Taniguchi T. FEBS Lett. 1998; 425: 112-116Crossref PubMed Scopus (224) Google Scholar, 7Schafer S.L. Lin R. Moore P.A. Hiscott J. Pitha P.M. J. Biol. Chem. 1998; 273: 2714-2720Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar, 8Wathelet M.G. Lin C.H. Parekh B.S. Ronco L.V. Howley P.M. Maniatis T. Mol. Cell. 1998; 1: 507-518Abstract Full Text Full Text PDF PubMed Scopus (649) Google Scholar, 9Weaver B.K. Kumar K.P. Reich N.C. Mol. Cell. Biol. 1998; 18: 1359-1368Crossref PubMed Scopus (296) Google Scholar, 10Yoneyama M. Suhara W. Fukuhara Y. Fukuda M. Nishida E. Fujita T. EMBO J. 1998; 17: 1087-1095Crossref PubMed Scopus (679) Google Scholar). Phosphorylation of IRF3 leads to its nuclear translocalization, association with the co-activator cAMP-response element binding protein-binding protein (CBP), and potentiation of its transcriptional activity. Hence, activated IRF3 can induce a specific set of genes in response to viral infection (11Kim T.K. Maniatis T. Mol. Cell. 1997; 1: 119-129Abstract Full Text Full Text PDF PubMed Scopus (295) Google Scholar, 12Kim T.K. Kim T.H. Maniatis T. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 12191-12196Crossref PubMed Scopus (93) Google Scholar, 13Maniatis T. Falvo J.V. Kim T.H. Kim T.K. Lin C.H. Parekh B.S. Wathelet M.G. Cold Spring Harb. Symp. Quant. Biol. 1998; 63: 609-620Crossref PubMed Scopus (313) Google Scholar). Some further clues to the function of IRF3 may be provided by another IRF family protein, IRF1. The expression level of IRF1 increases in response to viral infection, and also in response to DNA-damaging agents (14Fujita T. Kimura Y. Miyamoto M. Barsoumian E.L. Taniguchi T. Nature. 1989; 337: 270-272Crossref PubMed Scopus (315) Google Scholar, 15Fujita T. Reis L.F. Watanabe N. Kimura Y. Taniguchi T. Vilcek J. Proc. Natl. Acad. Sci. U. S. A. 1989; 86: 9936-9940Crossref PubMed Scopus (250) Google Scholar). IRF1 regulates specific target genes, thereby inducing cell cycle arrest and/or apoptosis in response to genotoxic stress (16Tamura T. Ishihara M. Lamphier M.S. Tanaka N. Oishi I. Aizawa S. Matsuyama T. Mak T.W. Taki S. Taniguchi T. Nature. 1995; 376: 596-599Crossref PubMed Scopus (418) Google Scholar,17Tanaka N. Ishihara M. Lampier M.S. Nozawa H. Matsuyama T. Mak T.W. Aizawa S. Tokino T. Oren M. Taniguchi T. Nature. 1996; 382: 816-818Crossref PubMed Scopus (301) Google Scholar). In addition, functional inactivation of IRF1 contributes to aberrant cell growth, consistent with its implicated role as a tumor suppressor gene (18Harada H. Willison K. Sakakibara J. Miyamoto M. Fujita T. Taniguchi T. Cell. 1990; 63: 303-312Abstract Full Text PDF PubMed Scopus (317) Google Scholar, 19Harada H. Kitagawa M. Tanaka N. Yamamoto H. Harada K. Ishihara M. Taniguchi T. Science. 1993; 259: 971-974Crossref PubMed Scopus (427) Google Scholar, 20Tanaka N. Ishihara M. Kitagawa M. Harada H. Kimura T. Matsuyama T. Lampier M. Aizawa S. Mak T.W. Taniguchi T. Cell. 1994; 77: 829-839Abstract Full Text PDF PubMed Scopus (464) Google Scholar). Because both IRF1 and IRF3 recognize similar regulatory DNA sequences, these observations raised the potential role of IRF3 in the DNA damage response. Despite its demonstrated role in the response to viral infection, little is known about whether IRF3 is involved in responses to other environmental stresses. In the present study, we tested whether DNA-damaging agents could activate IRF3. We found that in response to several DNA-damaging agents, IRF3 is phosphorylated, binds to CBP, moves to the nucleus, and increases transcription from its binding sites. These data suggest that IRF3 is involved in the defensive responses against genotoxic stress. The wild-type and mutated (S385A and S386A) IRF3 expression plasmids were described previously (10Yoneyama M. Suhara W. Fukuhara Y. Fukuda M. Nishida E. Fujita T. EMBO J. 1998; 17: 1087-1095Crossref PubMed Scopus (679) Google Scholar). For the construction of GAL4-IRF3, GAL4-IRF1, and green fluorescent protein (GFP)-IRF3, the IRF3 and IRF1 cDNAs inserts were obtained by polymerase chain reaction, and the resultant products were cloned into the GAL4 plasmid pSG424 (21Sadowski I. Ptashne M. Nucleic Acids Res. 1989; 17: 7539Crossref PubMed Scopus (470) Google Scholar) or the GFP plasmid pEGFP-N1 (CLONTECH). The G5E1b-CAT reporter plasmid containing five GAL4 DNA binding sites with an E1b TATA box was described previously (22Lillie J.W. Green M.R. Nature. 1989; 338: 39-44Crossref PubMed Scopus (471) Google Scholar). For construction of the IRF6-CAT reporter plasmid, six copies of the IRF DNA binding site were generated by multimerization of the interferon-β enhancer element (PRDI/III), and cloned into the −40 interferon β-CAT plasmid containing the interferon-β minimal promoter region and the CAT reporter gene (8Wathelet M.G. Lin C.H. Parekh B.S. Ronco L.V. Howley P.M. Maniatis T. Mol. Cell. 1998; 1: 507-518Abstract Full Text Full Text PDF PubMed Scopus (649) Google Scholar,13Maniatis T. Falvo J.V. Kim T.H. Kim T.K. Lin C.H. Parekh B.S. Wathelet M.G. Cold Spring Harb. Symp. Quant. Biol. 1998; 63: 609-620Crossref PubMed Scopus (313) Google Scholar). HeLa cells were maintained in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum, 2 mml-glutamine, 100 μg/ml penicillin, and 100 μg/ml streptomycin. Cells were transfected by plasmids using liposome reagents (FuGene from Roche Molecular Biochemicals; LipofectAMINE from Life Technologies, Inc.). At 24–36 h posttransfection, cells were irradiated with UV (50 J/m2) or incubated with recombinant interferon γ (500 units/ml), Sendai virus (200 hemagglutinating units/ml), doxorubicin (1 μg/ml), mitomycin C (1 μg/ml), cisplatin (0.5 μg/ml), or etoposide (1 μg/ml) as described (8Wathelet M.G. Lin C.H. Parekh B.S. Ronco L.V. Howley P.M. Maniatis T. Mol. Cell. 1998; 1: 507-518Abstract Full Text Full Text PDF PubMed Scopus (649) Google Scholar, 16Tamura T. Ishihara M. Lamphier M.S. Tanaka N. Oishi I. Aizawa S. Matsuyama T. Mak T.W. Taki S. Taniguchi T. Nature. 1995; 376: 596-599Crossref PubMed Scopus (418) Google Scholar, 17Tanaka N. Ishihara M. Lampier M.S. Nozawa H. Matsuyama T. Mak T.W. Aizawa S. Tokino T. Oren M. Taniguchi T. Nature. 1996; 382: 816-818Crossref PubMed Scopus (301) Google Scholar). Expression of the CAT reporter gene was analyzed 12–15 h after treatment. Transfection efficiencies were monitored by transfection of a CMV-lacZ control plasmid on parallel plates. CAT and β-galactosidase assays were performed as described (23Sambrook J. Fritsch E.F. Maniatis T. Molecular Cloning: A Laboratory Manual. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1989Google Scholar). CAT activities were normalized to protein concentrations of cell extracts because the CMV promoter includes elements that are known to be inducible in response to genotoxic stress (24Bauerle P.A. Baltimore D. Cell. 1996; 87: 13-20Abstract Full Text Full Text PDF PubMed Scopus (2910) Google Scholar, 25Maniatis T. Genes Dev. 1999; 13: 505-510Crossref PubMed Scopus (368) Google Scholar, 26Ip Y.T. Davis R.J. Curr. Opin. Cell Biol. 1998; 10: 205-219Crossref PubMed Scopus (1369) Google Scholar, 27Karin M. J. Biol. Chem. 1995; 270: 16483-16486Abstract Full Text Full Text PDF PubMed Scopus (2239) Google Scholar). All of the transfection experiments were repeated at least twice, and deviations were less than 10% of the mean for each data point. HA-tagged IRF3 was immunoprecipitated as described (28Harlow H. Lane D. Antibodies: A Laboratory Mannual. Cold Spring Harbor Laboratory, Cold Spring Harbor, NY1988Google Scholar) with minor modifications. Cell pellets were lysed by addition of Buffer A (20 mm Tris, pH 7.5, 150 mm NaCl, 25 mm β-glycerolphosphate, 2 mm EDTA, 1 mm sodium orthovanadate, 0.1% Nonidet P-40, 10% glycerol, 10 μg/ml leupeptin, 1 mmphenylmethylsulfonyl fluoride, and 1 mm dithiothreitol), followed by three freeze/thaw cycles. After centrifugation of cell lysates at 14,000 × g for 5 min at 4 °C, the supernatant was incubated with anti-HA antibody in Buffer A. After 1 h of end-over-end rotation at 4 °C, the immunoprecipitates were washed three times with Buffer A prior to further analysis. Some immunoprecipitates were treated with calf intestine alkaline phosphatase (5 units) (Amersham Pharmacia Biotech), as described (29Kim T.K. Maniatis T. Science. 1996; 273: 1717-1719Crossref PubMed Scopus (360) Google Scholar). Proteins were separated by SDS-PAGE and transferred to the nitrocellulose membranes (Millipore). The membranes were blocked with 5% nonfat milk and probed with anti-CBP (Santa Cruz Biotechnology) and anti-IRF3 antibodies. Membranes were then incubated with horseradish peroxidase-conjugated secondary antibodies and developed using the ECL system (Amersham Pharmacia Biotech). To identify agents that directly induce IRF3, we fused the IRF3 coding region to the DNA binding domain of GAL4 and examined the transcriptional activity of the GAL4-IRF3 fusion protein with a reporter plasmid containing GAL4 binding sites (Fig.1 A). Expression of GAL4-IRF3 under the control of the constitutive CMV promoter resulted in a low level of reporter gene expression (lane 2). IRF3-dependent gene expression was specifically stimulated by viral infection (lane 3) but not by interferon γ treatment (lane 4). Interestingly, the transcriptional activity of GAL4-IRF3 was strongly stimulated by UV radiation, which is known to cause genotoxic stress (lane 5). Doxorubicin, a DNA-damaging agent that induces DNA breaks, also potentiated the transcriptional activity of GAL4-IRF3 (lane 6). In contrast, expression of GAL4-IRF1 under the same conditions resulted in constitutive levels of transcription that were not affected by any of the agents tested (lanes 9–12). To find whether UV and doxorubicin can stimulate the transcriptional activity of IRF3 at its own binding site, we transfected a native IRF3 expression plasmid (containing no GAL4 DNA binding domain) along with a reporter plasmid (IRF6-CAT) containing six IRF3 DNA binding sites. In the absence of the IRF3 expression plasmid, UV and doxorubicin induced some CAT activity, possibly due to the activity of endogenous IRF3 (Fig. 1 B, lanes 2 and 3). With increasing amounts of IRF3 expression, the induction of the reporter gene dramatically increased in a dosage-dependent manner (lanes 5 and 8 and lanes 6 and9). These results suggest that the transcriptional activity of IRF3 can be stimulated by UV and doxorubicin. To determine the specificity of the UV/doxorubicin-induced transcriptional activity, we tested whether mutants of IRF3 (S385A or S386A) affect reporter gene expression from the IRF3 promoter (Fig.2). Mutation of residues Ser-385 and Ser-386 is known to block the activation of IRF3 in response to viral infection (10Yoneyama M. Suhara W. Fukuhara Y. Fukuda M. Nishida E. Fujita T. EMBO J. 1998; 17: 1087-1095Crossref PubMed Scopus (679) Google Scholar). UV and doxorubicin activated the expression of the reporter gene from the IRF6-CAT plasmid in the absence of transfected IRF3 (Fig. 2, lanes 2 and 3). Wild-type IRF3 further stimulated this genotoxic stress-induced gene expression (Fig. 2, lanes 5 and 6). In contrast, mutant IRF3 (S385A or S386A) did not increase the repoter activity (Fig. 2, compare lanes 2 and 3 with lanes 8 and 9 and lanes 11 and 12). In fact, the IRF3 mutants slightly reduced the activity, possibly by inhibition of endogenous wild-type IRF3 activity. Thus, the two serine residues in the IRF3 activation domain are essential for its induced transcriptional activity by UV and doxorubicin. To determine whether the activation of IRF3 is correlated to its phosphorylation, we examined the effect of UV and doxorubicin on the electrophoretic mobility of IRF3 during SDS-PAGE (Fig.3). Treatment with UV or doxorubicin caused a reduction in the electrophoretic mobility of IRF3 (lanes 2 and 3). This mobility shift was similar to that caused by viral infection (lane 4). Importantly, no shift in the electrophoretic mobility of IRF3 was detected in the presence of calf intestine alkaline phosphatase (lanes 5–7). Thus, the mobility shift was caused by phosphorylation of IRF3 upon treatment with UV, doxorubicin, or virus. It has been reported that viral infection induces the phosphorylation of IRF3, thereby allowing it to bind to the transcriptional co-activator CBP with simultaneous nuclear translocation (3Juang Y. Lowther W. Kellum M. Au W. Lin R. Hiscott J. Pitha P.M. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 9837-9842Crossref PubMed Scopus (236) Google Scholar, 4Lin R. Heylbroeck C. Pitha P.M. Hiscott J. Mol. Cell. Biol. 1998; 18: 2986-2996Crossref PubMed Scopus (742) Google Scholar, 5Navarro L. Mowen K. Rodems S. Weaver B. Reich N. Spector D. David M. Mol. Cell. Biol. 1998; 18: 3796-3802Crossref PubMed Scopus (133) Google Scholar, 6Sato M. Tanaka N. Hata N. Oda E. Taniguchi T. FEBS Lett. 1998; 425: 112-116Crossref PubMed Scopus (224) Google Scholar, 7Schafer S.L. Lin R. Moore P.A. Hiscott J. Pitha P.M. J. Biol. Chem. 1998; 273: 2714-2720Abstract Full Text Full Text PDF PubMed Scopus (255) Google Scholar, 8Wathelet M.G. Lin C.H. Parekh B.S. Ronco L.V. Howley P.M. Maniatis T. Mol. Cell. 1998; 1: 507-518Abstract Full Text Full Text PDF PubMed Scopus (649) Google Scholar, 9Weaver B.K. Kumar K.P. Reich N.C. Mol. Cell. Biol. 1998; 18: 1359-1368Crossref PubMed Scopus (296) Google Scholar, 10Yoneyama M. Suhara W. Fukuhara Y. Fukuda M. Nishida E. Fujita T. EMBO J. 1998; 17: 1087-1095Crossref PubMed Scopus (679) Google Scholar). Thus, we investigated the subcellular localization of IRF3 in response to UV and doxorubicin. IRF3 linked to the GFP was transfected into HeLa cells. The cells were treated with UV or doxorubicin and examined for changes in the subcellular localization of IRF3 (Fig.4). In uninduced cells, GFP-IRF3 was localized almost exclusively to the cytoplasm. UV or doxorubicin treatment resulted in the translocation of GFP-IRF3 into the nucleus (Fig. 4) in concert with the change in the electrophoretic mobility (Fig. 3). To examine the possibility that IRF3 associates with the co-activator CBP following UV/doxorubicin induction, IRF3 was immunoprecipitated from uninduced and induced cells (Fig.5). Consistent with the data in Fig. 3, treatment with UV or doxorubicin induced the phosphorylation of IRF3, as demonstrated by its mobility shift (lanes 2 and3). Under these conditions, the immunoblot for CBP revealed that CBP was co-immunoprecipitated with IRF3 from treated cells (lanes 2 and 3) but not from untreated cells (lane 1). Thus, UV and doxorubicin induced the nuclear localization of IRF3 (Fig. 4) and the interaction of IRF3 with the transcriptional co-activator CBP (Fig. 5), both of which would be important for the regulation of IRF3 target genes in the nucleus. We showed that IRF3 can be activated by UV and doxorubicin (Figs.Figure 1, Figure 2, Figure 3, Figure 4, Figure 5). To investigate whether IRF3 is activated in response to other DNA-damaging agents, we examined the transcriptional activity of GAL4-IRF3 in the presence of mitomycin C, cisplatin, and etoposide. These agents were chosen because of the distinct mechanisms by which they induce genotoxic stress (30Fritsche M. Haessler C. Brandner G. Oncogene. 1993; 8: 307-318PubMed Google Scholar). UV radiation induces several types of DNA damage, including thymine dimer formation; doxorubicin is a DNA-intercalating agent that binds to topoisomerase II, causing DNA strand cleavage; mitomycin C alkylates DNA; cisplatin generates various DNA adducts through platinum-DNA complex formation; and etoposide (vinca alkaloids) triggers DNA strand cleavage through formation of a ternary complex with DNA and topoisomerase II. The transcriptional activity of GAL4-IRF3 was strongly stimulated by treatment with mitomycin C, cisplatin, and etoposide, as well as doxorubicin (Fig.6). Thus, all the tested inducers of genotoxic stress, despite their different mechanisms, potentiated the transcriptional activity of IRF3. In the present study, we have identified the activation pathway of IRF3 in response to DNA-damaging agents, including UV radiation and doxorubicin. Several other agents (mitomycin C, cisplatin, and etoposide) were also shown to potentiate the transcriptional activity of IRF3, although they are known to induce DNA damage through different mechanisms. These results implicate IRF3 as a general mediator of pathways that respond to genotoxic stress. However, IRF3 is unlikely to be involved in all stress responses, because other types of stress inducers, including proinflammatory cytokines, tumor necrosis factor-α, and interleukin-1, fail to activate IRF3 (4Lin R. Heylbroeck C. Pitha P.M. Hiscott J. Mol. Cell. Biol. 1998; 18: 2986-2996Crossref PubMed Scopus (742) Google Scholar). Upon treatment with DNA-damaging agents, IRF3 could be activated by DNA damage itself and/or by some signaling pathways resulting from the DNA damage. A variety of genotoxic stresses are known to activate p53 (reviewed in Refs. 31Giaccia A.J. Kastan M.B. Genes Dev. 1998; 12: 2973-2983Crossref PubMed Scopus (1167) Google Scholar, 32Hansen R. Oren M. Curr. Opin. Genet. Dev. 1997; 7: 46-51Crossref PubMed Scopus (206) Google Scholar, 33Ko L.J. Prives C. Genes Dev. 1996; 10: 1054-1072Crossref PubMed Scopus (2279) Google Scholar, 34Weinert T. Cell. 1998; 94: 555-558Abstract Full Text Full Text PDF PubMed Scopus (236) Google Scholar), including DNA-damaging agents such as those that activate IRF3 in this study. Despite extensive studies, the mechanisms by which DNA-damaging agents activate p53 are not clearly established. In the case of UV radiation, the initial signal leading to p53 induction appears to be dependent on DNA strand cleavage, which can be caused either by excision repair or replication past thymine dimers (35Nelson W.G. Kastan M. Mol. Cell. Biol. 1994; 14: 1815-1823Crossref PubMed Scopus (868) Google Scholar). It has also been suggested that UV induces p53 through unknown signaling pathways triggered by the blockage of transcription and DNA synthesis (36Chernova O.B. Chernov M.V. Agarwal M.L. Taylor W.R. Stark G.R. Trends Biochem. Sci. 1995; 20: 431-434Abstract Full Text PDF PubMed Scopus (73) Google Scholar). Related to this, α-amanitin or aphidicolin, which are the specific inhibitors of RNA polymerase or DNA polymerase, respectively, increase p53 protein levels (reviewed in Ref. 36Chernova O.B. Chernov M.V. Agarwal M.L. Taylor W.R. Stark G.R. Trends Biochem. Sci. 1995; 20: 431-434Abstract Full Text PDF PubMed Scopus (73) Google Scholar). These inhibitors failed to significantly induce phosphorylation of IRF3 as compared with its phosphorylation induced by UV. 2T. Kim and T. K. Kim, unpublished data. Thus IRF3 may not be efficiently activated by inhibition of transcription or DNA synthesis. The exact mechanisms by which DNA-damaging agents activate IRF3 (as well as p53) remain to be elucidated. In response to genotoxic stress, cells activate signaling pathways that lead either to damage repair with cell cycle arrest, or to apoptotic cell death. One member of the IRF family, IRF1, was previously demonstrated to be important for genotoxic stress-induced cell cycle arrest and apoptosis (16Tamura T. Ishihara M. Lamphier M.S. Tanaka N. Oishi I. Aizawa S. Matsuyama T. Mak T.W. Taki S. Taniguchi T. Nature. 1995; 376: 596-599Crossref PubMed Scopus (418) Google Scholar, 17Tanaka N. Ishihara M. Lampier M.S. Nozawa H. Matsuyama T. Mak T.W. Aizawa S. Tokino T. Oren M. Taniguchi T. Nature. 1996; 382: 816-818Crossref PubMed Scopus (301) Google Scholar). In response to DNA-damaging agents, the IRF1 gene is induced, and it stimulates transcription of the p21 cell cycle inhibitor and ICE apoptotic genes. Because both IRF1 and IRF3 recognize similar regulatory DNA sequences, it is conceivable that IRF3 may play some role in the regulation of the p21 and ICE genes during genotoxic stress responses. Consistent with this, we observed that cell proliferation was significantly reduced upon IRF3 activation by treatment with UV or doxorubicin and that ectopic expression of IRF3 induced p21 promoter activity. 3T. Y. Kim and T. K. Kim, unpublished data. It is possible that IRF3 is involved in the immediate-early response to genotoxic stress, whereas the delayed induction of genes may be controlled by IRF1. Related to this possibility, IRF3 is directly activated by phosphorylation, and phosphorylated IRF3 is rapidly degraded in the induced cells (4Lin R. Heylbroeck C. Pitha P.M. Hiscott J. Mol. Cell. Biol. 1998; 18: 2986-2996Crossref PubMed Scopus (742) Google Scholar). Thus, IRF3 protein becomes depleted at the time when IRF1 and other delayed genes are being synthesized. Sequential activation of the IRF proteins may provide very tight control mechanisms for the initial and delayed induction of target genes, amplifying the protective responses to genotoxic stress. In addition to IRF3, genotoxic stress stimulates signaling pathways that activate transcription factors including p53, AP-1, NF-κB, and YB-1. These transcription factors elicit various biological responses through induction of their specific target genes. For instance, p53 activation leads to the induction of the p21 cell cycle inhibitor gene and the bax apoptotic gene for cell cycle arrest and apoptosis (reviewed in Refs. 31Giaccia A.J. Kastan M.B. Genes Dev. 1998; 12: 2973-2983Crossref PubMed Scopus (1167) Google Scholar, 32Hansen R. Oren M. Curr. Opin. Genet. Dev. 1997; 7: 46-51Crossref PubMed Scopus (206) Google Scholar, 33Ko L.J. Prives C. Genes Dev. 1996; 10: 1054-1072Crossref PubMed Scopus (2279) Google Scholar, 34Weinert T. Cell. 1998; 94: 555-558Abstract Full Text Full Text PDF PubMed Scopus (236) Google Scholar). Although the role of AP-1 activation in response to genotoxic stress is not clearly established, its induction may help cells exit the G1 checkpoint imposed by p53 (reviewed in Refs.26Ip Y.T. Davis R.J. Curr. Opin. Cell Biol. 1998; 10: 205-219Crossref PubMed Scopus (1369) Google Scholar and 27Karin M. J. Biol. Chem. 1995; 270: 16483-16486Abstract Full Text Full Text PDF PubMed Scopus (2239) Google Scholar). Induction of NF-κB, on the other hand, appears to play an important role in preventing apoptosis (reviewed in Refs. 24Bauerle P.A. Baltimore D. Cell. 1996; 87: 13-20Abstract Full Text Full Text PDF PubMed Scopus (2910) Google Scholar, 25Maniatis T. Genes Dev. 1999; 13: 505-510Crossref PubMed Scopus (368) Google Scholar). Interestingly, YB-1 translocates into the nucleus in response to DNA-damaging agents. In some of cancer cells with multidrug resistance, its nuclear localization and increased protein levels correlate well with multidrug resistance-1 gene expression (37Bargou R.C. Jurchott K. Wagener C. Bergmann S. Metzner S. Bommert K. Mapara M.Y. Winzer K.-J. Dietel M. Dorken B. Royer H.-D. Nat. Med. 1997; 3: 447-450Crossref PubMed Scopus (369) Google Scholar, 38Wolffe A.P. Tafuri S. Ranjan M. Familari M. New Biol. 1992; 4: 290-298PubMed Google Scholar, 39Ladomery M. Sommerville J. Bioessays. 1995; 17: 9-11Crossref PubMed Scopus (126) Google Scholar, 40Ohga T. Koike K. Ono M. Makino Y. Itagaki Y. Tanimoto M. Kuwano M. Kohno K. Cancer Res. 1996; 56: 4224-4228PubMed Google Scholar, 41Goldsmith M.E. Madden M.J. Morrow C.S. Cowan K.H. J. Biol. Chem. 1993; 268: 5856-5860Abstract Full Text PDF PubMed Google Scholar, 42Osborn M.T. Chambers T.C. J. Biol. Chem. 1996; 271: 30950-30955Abstract Full Text Full Text PDF PubMed Scopus (214) Google Scholar, 43Koike K. Uchiumi T. Ohga T. Toh S. Wada M. Kohno K. Kuwano M. FEBS Lett. 1997; 417: 390-394Crossref PubMed Scopus (174) Google Scholar). Thus, we plan to examine the functional interaction of these transcription factors with IRF3 on the enhancers of target genes to further understand the biological function of IRF3. Various defensive responses, including cell cycle checkpoint and DNA repair mechanisms, have evolved to protect cells against the effects of DNA damage. Defects in these defense mechanisms are implicated in various human diseases, including cancer. Consistent with their critical roles in the response to genotoxic stress, mutations in the p53 and IRF1 tumor suppressor genes have been detected in human cancers (31Giaccia A.J. Kastan M.B. Genes Dev. 1998; 12: 2973-2983Crossref PubMed Scopus (1167) Google Scholar, 32Hansen R. Oren M. Curr. Opin. Genet. Dev. 1997; 7: 46-51Crossref PubMed Scopus (206) Google Scholar, 33Ko L.J. Prives C. Genes Dev. 1996; 10: 1054-1072Crossref PubMed Scopus (2279) Google Scholar, 34Weinert T. Cell. 1998; 94: 555-558Abstract Full Text Full Text PDF PubMed Scopus (236) Google Scholar, 44Willman C.L. Sever C.E. Pallavicini M.G. Harada H. Tanaka N. Slovak M.L. Yamamoto H. Harada K. Meeker T.C. List A.F. Taniguchi T. Science. 1993; 259: 968-971Crossref PubMed Scopus (379) Google Scholar). So far, no mutation in the IRF3 gene has been associated with human cancer. However, several viral oncoproteins, including human papillomavirus 16 E6 and adenovirus E1A, can inhibit the activation of IRF3 and p53, but not IRF1 (3Juang Y. Lowther W. Kellum M. Au W. Lin R. Hiscott J. Pitha P.M. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 9837-9842Crossref PubMed Scopus (236) Google Scholar, 45Ronco L.V. Karpova A.Y. Vidal M. Howley P.M. Genes Dev. 1998; 12: 2061-2072Crossref PubMed Scopus (496) Google Scholar). In view of the results presented here, it will be important to investigate how the inactivation of IRF3 is connected with the loss of defensive functions against genotoxic stress during tumorigenesis. In future studies, we will attempt to identify the specific target genes of IRF3 and to generate mice deficient in the IRF3 gene to analyze their susceptibility to DNA damage-induced tumors. We thank Dr. Fujita for providing the IRF3 reagents." @default.
• W2017190892 created "2016-06-24" @default.
• W2017190892 creator A5010639228 @default.
• W2017190892 creator A5020742231 @default.
• W2017190892 creator A5028357898 @default.
• W2017190892 creator A5029777489 @default.
• W2017190892 creator A5035939873 @default.
• W2017190892 creator A5060860299 @default.
• W2017190892 date "1999-10-01" @default.
• W2017190892 modified "2023-10-17" @default.
• W2017190892 title "Activation of Interferon Regulatory Factor 3 in Response to DNA-damaging Agents" @default.
• W2017190892 cites W1556824391 @default.
• W2017190892 cites W1890314278 @default.
• W2017190892 cites W1977041491 @default.
• W2017190892 cites W1978624555 @default.
• W2017190892 cites W1982170462 @default.
• W2017190892 cites W1985476964 @default.
• W2017190892 cites W1986559713 @default.
• W2017190892 cites W1988803122 @default.
• W2017190892 cites W1994718301 @default.
• W2017190892 cites W1995449101 @default.
• W2017190892 cites W2001237845 @default.
• W2017190892 cites W2002301799 @default.
• W2017190892 cites W2005725217 @default.
• W2017190892 cites W2013036001 @default.
• W2017190892 cites W2014722055 @default.
• W2017190892 cites W2024278937 @default.
• W2017190892 cites W2028297274 @default.
• W2017190892 cites W2028850807 @default.
• W2017190892 cites W2033417996 @default.
• W2017190892 cites W2037772620 @default.
• W2017190892 cites W2040470926 @default.
• W2017190892 cites W2048372727 @default.
• W2017190892 cites W2050194267 @default.
• W2017190892 cites W2053472341 @default.
• W2017190892 cites W2055952888 @default.
• W2017190892 cites W2072457100 @default.
• W2017190892 cites W2075496313 @default.
• W2017190892 cites W2088245792 @default.
• W2017190892 cites W2090162429 @default.
• W2017190892 cites W2093897768 @default.
• W2017190892 cites W2095194341 @default.
• W2017190892 cites W2112534911 @default.
• W2017190892 cites W2118897660 @default.
• W2017190892 cites W2130576390 @default.
• W2017190892 cites W2150710841 @default.
• W2017190892 cites W2151064612 @default.
• W2017190892 cites W2156299289 @default.
• W2017190892 cites W2156947910 @default.
• W2017190892 cites W2564590762 @default.
• W2017190892 cites W4362205050 @default.
• W2017190892 doi "https://doi.org/10.1074/jbc.274.43.30686" @default.
• W2017190892 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/10521456" @default.
• W2017190892 hasPublicationYear "1999" @default.
• W2017190892 type Work @default.
• W2017190892 sameAs 2017190892 @default.
• W2017190892 citedByCount "88" @default.
• W2017190892 countsByYear W20171908922012 @default.
• W2017190892 countsByYear W20171908922013 @default.
• W2017190892 countsByYear W20171908922014 @default.
• W2017190892 countsByYear W20171908922015 @default.
• W2017190892 countsByYear W20171908922016 @default.
• W2017190892 countsByYear W20171908922017 @default.
• W2017190892 countsByYear W20171908922018 @default.
• W2017190892 countsByYear W20171908922019 @default.
• W2017190892 countsByYear W20171908922020 @default.
• W2017190892 countsByYear W20171908922021 @default.
• W2017190892 countsByYear W20171908922023 @default.
• W2017190892 crossrefType "journal-article" @default.
• W2017190892 hasAuthorship W2017190892A5010639228 @default.
• W2017190892 hasAuthorship W2017190892A5020742231 @default.
• W2017190892 hasAuthorship W2017190892A5028357898 @default.
• W2017190892 hasAuthorship W2017190892A5029777489 @default.
• W2017190892 hasAuthorship W2017190892A5035939873 @default.
• W2017190892 hasAuthorship W2017190892A5060860299 @default.
• W2017190892 hasBestOaLocation W20171908921 @default.
• W2017190892 hasConcept C104317684 @default.
• W2017190892 hasConcept C185592680 @default.
• W2017190892 hasConcept C2776178377 @default.
• W2017190892 hasConcept C32300475 @default.
• W2017190892 hasConcept C54355233 @default.
• W2017190892 hasConcept C552990157 @default.
• W2017190892 hasConcept C70721500 @default.
• W2017190892 hasConcept C86339819 @default.
• W2017190892 hasConcept C86803240 @default.
• W2017190892 hasConcept C9173399 @default.
• W2017190892 hasConcept C95444343 @default.
• W2017190892 hasConceptScore W2017190892C104317684 @default.
• W2017190892 hasConceptScore W2017190892C185592680 @default.
• W2017190892 hasConceptScore W2017190892C2776178377 @default.
• W2017190892 hasConceptScore W2017190892C32300475 @default.
• W2017190892 hasConceptScore W2017190892C54355233 @default.
• W2017190892 hasConceptScore W2017190892C552990157 @default.
• W2017190892 hasConceptScore W2017190892C70721500 @default.
• W2017190892 hasConceptScore W2017190892C86339819 @default.
• W2017190892 hasConceptScore W2017190892C86803240 @default.
• W2017190892 hasConceptScore W2017190892C9173399 @default.
• W2017190892 hasConceptScore W2017190892C95444343 @default.

• next