The functional importance of a cap site-proximal region of the human prointerleukin 1 beta gene is defined by viral protein trans-activation.

Hunninghake, Gary W.; Monks, Brian G.; Geist, Lois J.; Monick, Martha M.; Monroy, Manuel; Stinski, Mark F.; Webb, Andrew C.; Jm, Dayer; Auron, Philip E.; Fenton, Matthew J.

doi:10.1128/mcb.12.8.3439

Cited by 60 publications

(45 citation statements)

References 47 publications

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“…Unincorporated nucleotides were removed using Sephadex G-25 columns (5 Prime33 Prime, Boulder, CO). Nuclear extracts (typically 5 g) were incubated with radiolabeled probe DNA (0.1 ng, typically 10,000 cpm) in the presence of 2 g of poly(dI-dC)⅐(dI-dC) (Pharmacia, Piscataway, NJ), 1.0 mM EDTA, 10 mM Tris-HCl (pH 7.9), 25 mM glycerol, and 0.5 mM DTT as previously described (36,38). Binding reactions were incubated at room temperature for 30 min.…”

Section: Emsa Analysismentioning

confidence: 99%

PU.1 and Multiple IFN Regulatory Factor Proteins Synergize to Mediate Transcriptional Activation of the Human IL-1β Gene

Marecki

Riendeau

Liang

et al. 2001

The Journal of Immunology

101

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Both lymphoid and myeloid cells express two related members of the IFN regulatory factor (IRF) family of transcription factors, specifically IRF-4 and IFN consensus binding protein (ICSBP or IRF-8). We previously reported that macrophages express IRF-4 and in combination with the ETS-like protein PU.1 can synergistically activate a human IL-1β reporter gene. Here we report that this synergy is mediated by a composite PU.1/IRF element located within an upstream enhancer known to confer cytokine- and LPS-inducible expression. In macrophages, synergistic activation of IL-1β reporter gene expression was preferentially mediated by IRF-4, whereas IRF-4 and ICSBP were equally capable of synergizing with PU.1 when coexpressed in fibroblasts. Furthermore, coexpression of IRF-1 and IRF-2 dramatically increased the capacity of both PU.1/IRF-4 and PU.1/ICSBP to induce IL-1β reporter gene expression in fibroblasts. The additional synergy observed with IRF-1 and IRF-2 coexpression is mediated by a region of DNA distinct from either the IL-1β enhancer or promoter. We also assessed the capacity of these transcription factors to activate endogenous IL-1β gene when overexpressed in human embryonic kidney 293 cells. Although ectopic expression of PU.1 alone was sufficient to activate modest levels of IL-1β transcripts, endogenous IL-1β expression was markedly increased following coexpression of additional IRF proteins. Thus, maximal expression of both a human IL-1β reporter gene and the endogenous IL-1β gene was observed in cells that coexpressed PU.1, IRF-4 (or ICSBP), IRF1, and IRF2. Together, our observations suggest that these factors may function together as an enhanceosome.

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Section: Emsa Analysismentioning

confidence: 99%

PU.1 and Multiple IFN Regulatory Factor Proteins Synergize to Mediate Transcriptional Activation of the Human IL-1β Gene

Marecki

Riendeau

Liang

et al. 2001

The Journal of Immunology

101

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“…The only studies to date that have demonstrated a role for PU.1 in the regulation of the LPS response have come from work on the IL-1␤ gene and the human immunodeficiency virus-1 long terminal repeat. A cap site-proximal region of the human IL-1␤ promoter was shown to bind a factor originally termed NF␤A that was critical for the expression of IL-1␤ in response to LPS and cytomegalovirus immediate early gene products (26,27). NF␤A was later found to be identical to PU.1 (28).…”

mentioning

confidence: 99%

Secretory Interleukin-1 Receptor Antagonist Gene Expression Requires both a PU.1 and a Novel Composite NF-κB/PU.1/ GA-binding Protein Binding Site

Smith¹,

Carl²,

Lodie³

et al. 1998

Journal of Biological Chemistry

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The human secretory interleukin-1 receptor antagonist (secretory IL-1Ra) gene is controlled through three lipopolysaccharide (LPS)-responsive promoter elements, one of which was identified as an NF-B binding site. Sequence analysis of the secretory IL-1Ra promoter identified a potential PU.1 binding site located between positions ؊80 and ؊90 on the complementary strand overlapping the NF-B site. Gel shift analysis using this potential binding site with nuclear extracts from RAW 264.7 macrophages demonstrated the formation of three complexes, one LPS-inducible and two constitutive. The inducible factor was identified as NF-B, and the constitutive factors were identified as PU.1 and GA-binding protein. Site-directed mutagenesis of the ؊93 to ؊79 promoter region demonstrated that mutation of either the NF-B 5-half site or the PU.1/GA-binding protein half-site alone did not significantly decrease LPS responsiveness. However, a mutation that disrupted the binding of all three factors resulted in a 50% decrease in LPS responsiveness. A second PU.1 binding site centered at ؊230 was identified by gel shift and supershift assays. Mutation of the core GGAA region resulted in a 50% decrease in LPS-responsive promoter activity. Mutation of both the distal and proximal LPS response elements led to an almost complete loss of responsiveness. These data therefore suggest that the regulation of IL-1Ra gene expression is a complex event involving the interactions of three different transcription factors with a single cis-acting element and that the two PU.1 binding sites are the major response elements for LPS-induced IL-1Ra gene expression.Interleukin 1 is an important proinflammatory cytokine produced by a wide variety of cell types and has been implicated in the pathogenesis of acute and chronic inflammatory or autoimmune diseases (1). The discovery of a naturally occurring IL-1 receptor antagonist (IL-1Ra) 1 has suggested a means through which the pathologic effects of IL-1 can be modulated (2, 3). The human IL-1Ra gene encodes two closely related proteins that act as specific antagonists of the binding of IL-1␣ and IL-1␤ to both the type I and type II IL-1 receptors (4, 5). Despite being members of the IL-1 gene family (6) and binding to the same cell surface receptors with approximately equal affinities as IL-1␣ and IL-1␤ (7, 8), the IL-1Ra proteins exert no agonist activity.IL-1Ra was originally described as a 22-26-kDa secreted product of monocytes (9) but is now known to also exist as an 18-kDa intracellular molecule originally found in the cytoplasm of epithelial cells (10). These two isoforms of IL-1Ra, termed sIL-1Ra and icIL-1Ra for the secreted and intracellular variants, respectively, are produced by alternative splicing of two distinct first exons. The first exon for icIL-1Ra is located approximately 9.6 kilobase pairs upstream of the first exon for sIL-1Ra (11) and splices into an internal site with the sequences encoding for the sIL-1Ra signal peptide. Thus, icIL1Ra contains no secretory leader peptide and remai...

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“…Reports of studies using the human cytomegalovirus immediate-early 1 gene product have identified proximal promoter elements, localized between -131 and + 14 bp, which appear to be involved in IL-1,B upregulation (9,21,24). In addition, an element located near the TATA box was shown to bind a specific factor termed NFIL-10A and was found to be necessary for both basal and inducible levels of IL-1i promoter activity (21 (26). U937 cells stimulated with a combination of LPS and PMA show a synergistic induction in the level of IL-lp mRNA over either treatment alone (reference 28 and unpublished observations).…”

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confidence: 99%

A CRE/ATF-like site in the upstream regulatory sequence of the human interleukin 1 beta gene is necessary for induction in U937 and THP-1 monocytic cell lines.

Gray¹,

Chandra²,

Clay³

et al. 1993

Mol. Cell. Biol.

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Transfection of U937 and THP-1 cells with a recombinant plasmid, pIL1(4.0kb)-CAT, containing 4 As determined by EMSA, the factor binding to the CRE/ATF-like site was present in nuclear extracts prepared from both uninduced and induced THP-1 and U937 cells. However, the intensity of the band appeared to be increased when nuclear extracts from induced cells were used. In contrast to the CRE/ATF mutation, which resulted in the loss of promoter activity, mutation of the NF-KB-like site resulted in a moderate increase in activity in U937 cells. A similar increase in promoter activity was not observed in THP-1 cells. From these studies, we conclude that a CRE/ATF-like site and a factor or factors interacting with this site are essential for the maximum induction of the IL-11 gene in stimulated U937 and THP-1 cells.The interleukin 1 (IL-1) cytokines belong to a family of cytokines which include tumor necrosis factor alpha, interferons, and IL-6. These cytokines can act individually or in concert to exert an influence on a target cell or tissue (reviewed in reference 2). The IL-1 cytokines consist of two polypeptides, IL-la and IL-1,B, that have essentially the same activity although they are the products of two different genes (4,30,31

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The functional importance of a cap site-proximal region of the human prointerleukin 1 beta gene is defined by viral protein trans-activation.

Cited by 60 publications

References 47 publications

PU.1 and Multiple IFN Regulatory Factor Proteins Synergize to Mediate Transcriptional Activation of the Human IL-1β Gene

PU.1 and Multiple IFN Regulatory Factor Proteins Synergize to Mediate Transcriptional Activation of the Human IL-1β Gene

Secretory Interleukin-1 Receptor Antagonist Gene Expression Requires both a PU.1 and a Novel Composite NF-κB/PU.1/ GA-binding Protein Binding Site

A CRE/ATF-like site in the upstream regulatory sequence of the human interleukin 1 beta gene is necessary for induction in U937 and THP-1 monocytic cell lines.

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