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Query: UNIPROT:P05231 (
interleukin-6
)
23,907
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
A cDNA encoding NF-IL6, an
interleukin-6
(
IL-6
)-regulated human nuclear factor of the C/
EBP
family, is demonstrated to complement the transactivation function of E1A. The endogenous NF-IL6 level varies according to cell type and correlates positively with an
IL-6
-regulated cellular E1A-substituting activity that was described recently (J.M. Spergel and S. Chen-Kiang, Proc. Natl. Acad. Sci. USA 88:6472-6476, 1991). When expressed by transfection in cells which contain low levels of NF-IL6 and are incapable of complementing the function of E1A proteins, NF-IL6 also transactivates the E1A-responsive E2ae and E1B promoters, to the same magnitude as E1A. Activation by NF-IL6 is concentration dependent and sequence specific: mutational studies of the E2ae promoter suggest that the promoter-proximal NF-IL6 recognition site functions as a dominant negative regulatory site whereas the promoter-distal NF-IL6 recognition site is positively regulated at low NF-IL6 concentrations and negatively regulated when the NF-IL6 level is high. Consistent with these functions, NF-IL6 alone is sufficient to complement an E1A deletion mutant dl312 in viral infection, when expressed at appropriate concentrations. These results identify NF-IL6 as a sequence-specific cellular nuclear factor which regulates E1A-responsive genes in the absence of E1A.
...
PMID:NF-IL6, a member of the C/EBP family, regulates E1A-responsive promoters in the absence of E1A. 130 87
3T3-L1 preadipocytes differentiate into cells having the biochemical properties of adipocytes; tumour necrosis factor-alpha (TNF) attenuates this process. Inhibition of differentiation by this cytokine, thought to be mediated at the level of transcription, has been investigated by examining the accumulation of mRNA for six transcription factors and three diversely regulated genes during the first 24 h of the differentiation process. Upon induction of differentiation, a rapid and major accumulation of c-fos and jun-B mRNA, which returned to near basal levels within 4-6 h, was observed. In contrast, c-jun mRNA, although rapidly expressed at the induction of differentiation, remained at relatively constant levels throughout the time-course. Exposure of the cells to 5 nM TNF potentiated the accumulation of all three mRNAs but most significantly that of c-jun (12-fold), which remained elevated for at least 24 h after treatment. In control differentiating cells, krox-20 and fos-B were expressed transiently from 30 min to 2 h, while fra-1 mRNA accumulated over an extended period of 1 to 8 h. Again, TNF enhanced the accumulation of these mRNAs. Accumulation of mRNA for C/
EBP
, a transcription factor proposed to control the expression of genes involved in the terminally differentiated state, was attenuated after exposure of the cells to TNF.
Interleukin-6
(
IL-6
) mRNA was expressed briefly (30 min to 2 h) and again transiently (at 8 h after induction of differentiation). TNF treatment markedly enhanced accumulation of
IL-6
message. We propose that an increased cellular content of one or more transcription factors or the suppression of C/
EBP
may be responsible for the attenuation of differentiation induced by exposure of the cells to TNF.
...
PMID:Regulation of transcription factor mRNA accumulation during 3T3-L1 preadipocyte differentiation by tumour necrosis factor-alpha. 151 26
Interleukin-6
(
IL-6
) is a multifunctional cytokine which acts on a wide variety of cells, exerting growth promotion, growth inhibition, or specific gene expression including cellular differentiation. The
IL-6
receptor system consists of two membrane proteins, a ligand-binding chain (IL-6R) and a non-ligand-binding signal transducer, gp130, both of which belong to the cytokine receptor family. Binding of
IL-6
to IL-6R triggers the association of IL-6R and gp130, and gp130 in turn transduces the signal. Despite its lack of
IL-6
binding property, gp130 is involved in the formation of high-affinity
IL-6
binding sites. This two-chain
IL-6
receptor system can be applied to some other cytokine receptors, such as IL-3R, IL-5R and GM-CSFR which share a second signal-transducing component. A nuclear factor for controlling
IL-6
gene expression (NF-IL6) is a leucine zipper-containing transcription factor and is homologous to C/
EBP
, a liver nuclear factor. NF-IL6 is also involved in the transcriptional regulation of various acute phase protein genes
IL-6
-triggered association of IL-6R and gp130 on hepatocytes, through intermediate steps including serine-phosphorylation of pre-existing NF-IL6 protein, leads to binding of NF-IL6 to
IL-6
-responsive elements and activation of acute-phase protein genes.
...
PMID:IL-6 receptor and mechanism of signal transduction. 161 96
The A2 vitellogenin gene of Xenopus laevis, which is expressed liver specifically, contains an A-activator-binding site (AABS) that mediates high in vitro transcriptional activity in rat liver nuclear extracts. Footprint experiments with DNase I and gel retardation assays revealed the binding of several proteins to AABS. Using binding sites of known DNA-binding proteins as competitors in the gel retardation assay, we found that the transcription factor C/
EBP
and/or one of its "iso-binders" as well as LFB1/HNF1 bound AABS. These interactions were confirmed by in vitro transcription experiments using various oligonucleotides as competitors. However, saturating amounts of C/
EBP
- and LFB1/HNF1-binding sites as competitors only partially blocked AABS-mediated transcriptional activity. This finding implies that at least a third distinct transcription factor interacts with AABS. In vitro transcription experiments revealed that AABS was present not only in the closely related Xenopus A1 vitellogenin gene but also in acute-phase genes as a liver-specific regulatory element known to confer the
interleukin-6
response. Both AABS and the
interleukin-6
response element are promoter modules interacting with at least three distinct transcription factors, including C/
EBP
and LFB1/HNF1.
...
PMID:Liver-specific gene expression: A-activator-binding site, a promoter module present in vitellogenin and acute-phase genes. 170 15
The initial phase of inflammation is accompanied by dramatic changes in the concentrations of certain plasma proteins.
Interleukin-6
(
IL-6
) is an important inducer of these acute phase proteins at the transcriptional level. The recently cloned nuclear factor NF-IL6, a potent trans-acting regulator of
IL-6
gene expression, has a region that is highly homologous to the liver-specific transcriptional factor C/
EBP
. Both factors recognize the same nucleotide sequence. In this study the recombinant NF-IL6 was shown to interact with the
IL-6
-responsive elements (IL-6REs) identified in the promoter region of several acute phase protein genes whose activity increases during the acute phase reaction. Furthermore, in competition experiments, formation of all the DNA-protein complexes by the IL-6RE and
IL-6
-treated hepatoma cell extracts was specifically decreased by adding either the 14-bp NF-IL6 binding motif identified in the
IL-6
promoter or the antibody against the recombinant NF-IL6. NF-IL6 was expressed at a minor level in mouse liver, but was dramatically induced after stimulation with
IL-6
. In contrast, the amount of C/
EBP
mRNA decreased considerably after
IL-6
stimulation. These results indicate that the NF-IL6 that regulated
IL-6
expression was also involved in regulation of expression of the acute phase protein genes. The ability of NF-IL6 to replace C/
EBP
may explain the positive and negative acute phase responses induced by
IL-6
.
...
PMID:Reciprocal expression of NF-IL6 and C/EBP in hepatocytes: possible involvement of NF-IL6 in acute phase protein gene expression. 171 Jan 43
Independent of de novo protein synthesis, interleukin-1,
interleukin-6
, and dexamethasone caused immediate stimulation of transcriptional activity of most major acute phase plasma protein genes in the rat hepatoma H-35 cells. However, activation of alpha 2-macroglobulin and alpha 1-acid glycoprotein genes were delayed by 2-4 h and required ongoing protein synthesis. The hormones also increased transiently the transcription of the junB gene and the amounts of JunB, C/
EBP
, and C/
EBP
-like mRNA. To identify whether JunB and C/
EBP
have the ability to control both the early and late acute phase reactants, expression vectors for mouse C/
EBP
and JunB together with reporter gene constructs containing recognized hormone-specific regulatory elements were introduced into hepatoma cells. C/
EBP
displayed prominent transactivation activity with the interleukin-1 and glucocorticoid regulatory elements of alpha 1-acid glycoprotein, the interleukin-1 regulatory element of haptoglobin gene, and the
interleukin-6
regulatory element of beta-fibrinogen. The
interleukin-6
regulatory elements of the first two genes and the glucocorticoid response element of the third gene were not affected by C/
EBP
. These data suggest that normal hormone activation of these three acute phase reactant genes might involve, in part, C/
EBP
-related factors which have a broad range of specificity. H-35 cells stably transformed with a mouse C/
EBP
expression vector showed an elevated basal level as well as cytokine inducible expression of some but not all acute phase reactants. Cotransfected JunB resulted in reduced activity of cytokine-responsive constructs and in lower transactivation by C/
EBP
. JunB appears to function as a modulator of plasma protein expression during the course of acute phase response.
...
PMID:Transcriptional regulation through cytokine and glucocorticoid response elements of rat acute phase plasma protein genes by C/EBP and JunB. 171 61
We analyzed a family of proteins from hepatoma cell nuclei that bind to
interleukin-6
responsive elements (IL-6REs) of several acute-phase genes. This family is characterized by leucine zipper domains compatible with that of the CCAAT/enhancer binding protein (C/
EBP
). A cDNA clone coding for a member of the family, IL-6DBP, was isolated; it is strongly homologous to C/
EBP
in the region of the basic domain and in the leucine zipper sequence. IL-6DBP and C/
EBP
can interact in vitro to form heterodimers that bind to DNA with the same specificity as the respective homodimers, and they can interact functionally in vivo. Both the DNA binding activity and the trans-activating capacity of IL-6DBP are induced in hepatoma cells by treatment with IL-6 through a posttranslational mechanism, implicating it as a nuclear target of IL-6 and as a mediator of the IL-6-dependent transcriptional activation of liver genes during the acute-phase response.
...
PMID:IL-6DBP, a nuclear protein involved in interleukin-6 signal transduction, defines a new family of leucine zipper proteins related to C/EBP. 217 80
We have cloned the promoter for the human third component of complement (C3) gene and have identified sequences involved in its regulation during the acute-phase response. A construct linking 199 bp of the C3 promoter to the firefly luciferase gene was found to be very responsive to interleukin-1 (IL-1) and modestly responsive to
interleukin-6
(
IL-6
) by transfection analysis in the human hepatoma line Hep3B2. Simultaneous treatment with the two cytokines showed a strong synergy between the actions of the two molecules. A 58-bp fragment (-127 to -70 bp) was shown by 5' and 3' deletional mutagenesis to contain cis-acting elements that mediated both the IL-1 response and the IL-1-plus-
IL-6
synergistic response of this promoter. When coupled to a heterologous promoter, this fragment enabled the synergistic induction by IL-1 plus
IL-6
. Sequences homologous to the palindrome ACATTGCACAATCT, which mediates the induction of the
IL-6
gene by IL-1 (S. Akira, H. Isshiki, T. Sugita, O. Tanabe, S. Kinoshita, Y. Nishio, T. Nakajima, T. Hirano, and T. Kishimoto, EMBO J. 9:1897-1906, 1990), and the core sequence of the
IL-6
-responsive element of the rat alpha 2-macroglobulin gene (CTGGGA; M. Hattori, L. J. Abraham, W. Northemann, and G. H. Fey, Proc. Natl. Acad. Sci. USA 87:2364-2368, 1990) are contained within this fragment in immediate juxtaposition and partially overlapping. Site-directed mutagenesis within this homology region drastically reduced the inducibility of the C3 promoter by either cytokine. DNase I footprinting analysis defined a binding site for the transcription factor CCAAT/enhancer-binding protein (C/
EBP
), which included the IL-1-responsive element-like sequence. No differences were seen between the footprints generated by using extracts from unstimulated and IL-1-stimulated Hep3B2 cells. However, gel retardation analyses revealed two IL-1-specific bands. The data suggest that the induction by IL-1 is mediated by a factor belonging to the family of C/
EBP
-related proteins.
...
PMID:A 58-base-pair region of the human C3 gene confers synergistic inducibility by interleukin-1 and interleukin-6. 224 55
Human aromatase cytochrome P450 catalyzes the ultimate reaction in the estrogen biosynthetic pathway by coupling with another enzyme, NADPH-cytochrome P450 reductase, in the endoplasmic reticulum. The expression of the gene encoding the enzyme (CYP19) is regulated, in part, by tissue-specific promoters through the use of alternative-splicing mechanisms. Recently, we have localized a transcriptional activating element at positions -2141 to -2115 relative to the major cap site of the gene, by transient expression analyses in human BeWo choriocarcinoma cells using the bacterial chloramphenicol acetytransferase reporter gene ligated with CYP19 promoter sequences which regulate expression in this tissue. Here, we report the isolation of a cDNA encoding a DNA-binding protein which binds specifically to the regulatory element. The deduced amino-acid sequence of the insert is identical to that corresponding to the DNA-binding domain and the dimerization domain of a transcription factor, nuclear factor
interleukin-6
(NF-IL6), a member of the CCAAT/enhancer-binding protein (C/
EBP
) family. Studies using specific antibodies against members of the C/
EBP
family demonstrate that NF-IL6 is the major nuclear factor binding to the regulatory element in BeWo cells; nevertheless. C/EBP alpha also seems to be involved. Disruption of the NF-IL6-binding site within the regulatory element resulted in the disappearance of the transcriptional enhancing activity of the element, indicating that NF-IL6 is at least one of the nuclear factor(s) which enhances transcription through binding to the cis-acting element. These results indicate the intrinsic importance of NF-IL6 in the transcriptional regulation of CYP19 expression.
...
PMID:Identification of a transcriptional regulatory factor for human aromatase cytochrome P450 gene expression as nuclear factor interleukin-6 (NF-IL6), a member of the CCAAT/enhancer-binding protein family. 763 40
The transcription rates of the rat serine protease inhibitor 2.3 and 2.1 genes (spi 2.3 and spi 2.1), which are normally very low and high, respectively, are inversely modulated during inflammation. Two growth-hormone-response elements (GHRE-I and GHRE-II) maintain the spi 2.1 gene under the stringent control of growth hormone [Le Cam, A., Pantescu, V., Paquereau, L., Legraverend, C., Fauconnier, G. & Asins, G. (1994) J. Biol. Chem. 269, 21532-21539], whereas spi 2.3 appears to escape control by this hormone, despite the presence in its promoter of a functional GHRE-I. A major difference between these two otherwise very similar genes is the presence in spi 2.3 of a specific 348-bp extension of the 3' untranslated region (3' UTR). Inserting this 3' UTR element downstream of the polyadenylation signal or upstream of the spi 2.3 promoter in constructs containing the chloramphenicol acetyltransferase gene strongly decreases basal transcription and inhibits growth-hormone-stimulated transcription, but poorly affects transcriptional stimulation by dexamethasone or
interleukin-6
. The spi 2.3 3' UTR extension also inhibits, basal and growth-hormone-induced transcription from the spi 2.1 promoter. Repressor activity appears to be distributed throughout the specific extension of the 3' UTR and seems to involve interactions with two types of 5' cis-acting promoter elements. The first is the GAGA box, a key control spi promoter element, whose mutation faithfully reproduces the effects of the 3' UTR silencer on spi 2.1 and spi 2.3 promoters. The second is represented by CCAAT enhancer-binding-protein-(C/
EBP
)-binding sites, whose functions are severely impaired by the spi 2.3-specific 3' UTR extension. The presence of this silencer in the spi 2.3 gene very likely accounts for the lack of basal of transcription in vivo and for induction of the gene during acute inflammation.
...
PMID:Transcriptional repression, a novel function for 3' untranslated regions. 764 61
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