Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pituitary peptide hormone prolactin (Prl) is a potent inducer of Nb2 T lymphoma cell proliferation. To analyze the early genetic response to the mitogenic signals of Prl, a cDNA library was constructed from Nb2 T cells stimulated for 4 h with Prl and the protein synthesis inhibitor cycloheximide. Of 26 distinct clones isolated by differential screening, one clone, designated c25, exhibited extremely rapid but transient kinetics of induction by Prl and superinduction by Prl plus cycloheximide. Run-on transcription analysis indicated that c25 gene transcription was induced greater than 20-fold within 30 to 60 min of Prl stimulation. Surprisingly, DNA sequence analysis of c25 cDNA revealed that this Prl-inducible early-response gene is the rat homolog of the mouse transcription factor interferon-regulatory factor 1 (IRF-1), sharing 91% coding sequence similarity with mouse IRF-1. At the protein level, rat IRF-1 shares 97% and 92% homology with mouse IRF-1 and human IRF-1, respectively, suggesting that this molecule has been functionally conserved throughout evolution. Our studies show that the gene for IRF-1 is an immediate-early gene in Prl-stimulated T cells, which suggests that IRF-1 is a multifunctional molecule. In addition to its role in regulating growth-inhibitory interferon genes, IRF-1 may, therefore, also play a stimulatory role in cell proliferation. The gene for IRF-1 is one of the earliest genes known to be transcriptionally regulated by Prl.
Mol Cell Biol 1990 Jun
PMID:Interferon-regulatory factor 1 is an immediate-early gene under transcriptional regulation by prolactin in Nb2 T cells. 234 69

We determined whether normal human lung fibroblasts expressed cell-associated thymocyte-stimulating activity in response to recombinant interleukin-1 (rIL-1) (alpha and beta) and recombinant tumor necrosis factor (rTNF). Individually, rIL-1 and rTNF induced fibroblast expression of thymocyte-stimulating activity, with rIL-1 being significantly more potent. Importantly, combining rIL-1 and rTNF resulted in a synergistic increase in fibroblast thymocyte-stimulating activity. This synergistic interaction was dose dependent for both cytokines and was not noted when gamma-interferon was combined with rIL-1 or rTNF. In all cases, the thymocyte-stimulating activity was the result of an IL-1 alpha-like moiety whose maximal production required protein synthesis. IL-1 alpha activity could be detected after as little as 4 h, peaked after 24 h, and returned toward normal with longer periods of cytokine-fibroblast incubation. However, cytokine-stimulated fibroblasts that no longer expressed IL-1 alpha activity could be induced to re-express this activity with repeat cytokine challenge. Induction of fibroblast IL-1 alpha by IL-1 and/or TNF may be an important mechanism amplifying IL-1-mediated biologic events at sites of local inflammation.
Am J Respir Cell Mol Biol 1990 Jul
PMID:Interleukin-1 and tumor necrosis factor synergistically stimulate lung fibroblast interleukin-1 alpha production. 236 34

This study demonstrates distinct virus-inducible enhanson properties for three regions of the human beta interferon (IFN-beta) promoter; maximum virus inducibility required syngerism among all three enhansons. Expression of the IRF-1 transcription factor differentially increased the expression of plasmids containing (AAGTGA)4 or PRDIII (-94 to -78) motifs but was inefficient in the induction of the intact IFN-beta promoter. The human T-cell lymphotropic virus type I Tax protein was a strong positive activator of PRDII (-64 to -55)-containing plasmids but was also unable to stimulate the IFN-beta promoter. Induction of the intact IFN-beta promoter linked to a reporter plasmid was achieved in lymphoid and epithelioid cellular backgrounds by a triple transfection with IRF-1 and Tax expression plasmids or a combination of IRF-1 and phorbol ester, indicating that at least two trans-activating events and the association of two proteins on the promoter template are required for IFN-beta activation.
Mol Cell Biol 1990 Aug
PMID:Synergism between distinct enhanson domains in viral induction of the human beta interferon gene. 237 Aug 59

Genomic and cDNA clones for bovine trophoblast interferon (IFN) have been isolated by probing a bovine genomic library and a bovine embryonic (day-18 post coitus) cDNA library respectively with the ovine trophoblast IFN cDNA. The two DNA sequences were identical; sequence analysis demonstrated 80% identity between the amino acid sequence of bovine trophoblast IFN and ovine trophoblast IFN, and 70% identity with a previously identified bovine IFN-alpha 2. Southern blotting of bovine genomic DNA indicated the presence of a minimum of three trophoblast IFN genes. Primer extension analysis identified the transcription start site in the 5' flanking region of the bovine IFN gene. Computer-aided analysis of the 5' flanking sequence demonstrated a similarity with that of bovine IFN-alpha 2 and the existence of a possible viral induction sequence.
J Mol Endocrinol 1990 Jun
PMID:Structure of an interferon-alpha 2 gene expressed in the bovine conceptus early in gestation. 237 76

The expression of the gene encoding the granulocyte-macrophage colony-stimulating factor (GM-CSF) is induced upon activation of T cells with phytohemagglutinin and active phorbolester and upon expression of tax1, a transactivating protein of the human T-cell leukemia virus type I. The same agents induce transcription from the interleukin-2 receptor alpha-chain and interleukin-2 genes, depending on promoter elements that bind the inducible transcription factor NF-kappa B (or an NF-kappa B-like factor). We therefore tested the possibility that the GM-CSF gene is also regulated by a cognate motif for the NF-kappa B transcription factor. A recent functional analysis by Miyatake et al. (S. Miyatake, M. Seiki, M. Yoshida, and K. Arai, Mol. Cell. Biol. 8:5581-5587, 1988) described a short promoter region in the GM-CSF gene that conferred strong inducibility by T-cell-activating signals and tax1, but no NF-kappa B-binding motifs were identified. Using electrophoretic mobility shift assays, we showed binding of purified human NF-kappa B and of the NF-kappa B activated in Jurkat T cells to an oligonucleotide comprising the GM-CSF promoter element responsible for mediating responsiveness to T-cell-activating signals and tax1. As shown by a methylation interference analysis and oligonucleotide competition experiments, purified NF-kappa B binds at positions -82 to -91 (GGGAACTACC) of the GM-CSF promoter sequence with an affinity similar to that with which it binds to the biologically functional kappa B motif in the beta interferon promoter (GGGAAATTCC). Two kappa B-like motifs at positions -98 to -108 of the GM-CSF promoter were also recognized but with much lower affinities. Our data provide strong evidence that the expression of the GM-CSF gene following T-cell activation is controlled by binding of the NF-kappa B transcription factor to a high-affinity binding site in the GM-CSF promoter.
Mol Cell Biol 1990 Mar
PMID:NF-kappa B as inducible transcriptional activator of the granulocyte-macrophage colony-stimulating factor gene. 240 68

A monoclonal antibody (RH1-38) which blocks multiple systems of cell-mediated cytotoxicity was functionally characterized. RH1-38 specifically blocks, in the absence of complement, natural killer (NK) activity (K562 targets) without any effect on NK-K562 conjugate formation. Kinetic studies suggested that the antibody blocks a step that occurs 30-120 min after effector populations are mixed with target cells. Single-cell cytotoxicity assays in agarose, combined with standard 51Cr release assays and Michaelis-Menten analysis revealed that RH1-38 markedly decreases Vmax and the number of active NK cells, again without any effect on the number of target-binding cells. The maximum recycling capacity was usually decreased, but in some experiments unchanged, in the presence of the monoclonal antibody. RH1-38 inhibited equally well whole peripheral blood mononuclear leukocytes (PBML), Percoll-fractionated lymphocytes enriched for NK activity, and interferon (IFN)-boosted NK activity. PBML exposed to RH1-38 and then washed mediated depressed NK activity which was partially reversed by subsequent treatment with IFN. These studies are most consistent with the hypothesis that RH1-38 inhibits a step late in the NK cytolytic mechanism rather than through an effect on conjugate formation. The primary effect is probably not on the IFN-generating or boosting mechanism, but a secondary effect on IFN-related mechanisms cannot be ruled out. Inhibition through an effect on a small lymphocyte modulator of NK activity is also unlikely but not rigorously excluded. Thus, RH1-38 appears to inhibit NK activity through a direct effect on NK effector cells, probably by interfering with a cell-surface molecule which is important in the expression of NK activity. The companion paper demonstrates that this monoclonal antibody immunoprecipitates a molecule which is very similar or identical to the LFA-1 antigen. Thus, RH1-38 recognizes either a novel epitope on the LFA-1 molecule or alternatively a distinct, functional killer cell surface molecule. The epitope appears to be involved in a late step in the cytolytic mechanism, possibly part of the effector cell lytic machinery.
Mol Immunol 1985 Jul
PMID:A monoclonal antibody (RH1-38) which inhibits multiple systems of cell-mediated cytotoxicity--II. Evidence that the epitope recognized is involved in a late step in the cytolytic mechanism. 241 11

We studied the effects of gamma interferon (IFN-gamma) on HLA class I gene expression, differentiation, and proliferative capacity of K562 human leukemia cells. In the uninduced state, K562 cells show little or no class I gene expression but actively express the erythroid-specific gamma-globin gene as well as genes associated with cell proliferation, including the transferrin receptor, c-myc, and alpha-actin genes At both the surface protein and mRNA levels, IFN-gamma induces class I and beta 2-microglobulin gene expression, but does not alter the expression of the gamma-globin, transferrin receptor, c-myc, or alpha-actin genes. A 10-fold maximal induction of both class I surface protein and mRNA occurs at 48 h and is reversible upon withdrawal of IFN-gamma from the culture medium. In vitro nuclear run-on transcription assays were performed to directly establish that IFN-gamma exerts an early effect at the level of transcription, with maximal transcription rates occurring within 4 h. The difference between the time course of transcription induction and that of mRNA accumulation suggests that the regulation of class I gene expression in this human leukemic cell line also involves posttranscriptional mechanisms. Measurements of cell proliferation rates and cell cycle distribution, as well as the reversibility of the effects of IFN-gamma, demonstrate that the selective induction of class I genes in these cells occurs in the absence of differentiation.
Mol Cell Biol 1986 May
PMID:Gamma interferon and 5-azacytidine cause transcriptional elevation of class I major histocompatibility complex gene expression in K562 leukemia cells in the absence of differentiation. 243 Dec 85

The hyporeactivity factor in interferon production by L-929 cells designated IRP (interferon repressing protein) has been studied. In particular, its localization and methods of its purification have been studied. The kinetics of IRP accumulation by producing cells correlate with the development of hyporeactivity condition. Most of IRP is localized in cell sap and in ribosomal fraction in evidence to regulatory role of repressor at the level of interferon mRNA translation. A 100-fold increase in repressor activity was achieved by IRP concentration by ammonium sulfate precipitation. IRP as well as interferon have been shown to possess high affinity to polyU sepharose. The preparations of IRP and interferon concentrated by ammonium sulfate precipitation were subsequently purified by fractioning in a polyI sepharose column. A 10,000-fold (6 x 10(4) U/mg) purification was achieved for IRP and 250-fold (10(4) U/mg) for interferon.
Mol Gen Mikrobiol Virusol 1985 Oct
PMID:[The state of hyporeactivity in interferon production: localization and partial purification of the factor repressing the interferon production]. 243 17

Native preparations of alpha, beta and gamma-interferons as well as recombinant beta-interferon and purified leukocyte alpha-interferon and purified leukocyte alpha-interferon exert antiviral and antiproliferative activity in CaOv cells. Native interferon preparations were shown to be more antiproliferative than purified interferons per unit of antiviral activity (with EMC as well as with less susceptible VSV used as test viruses). It was shown that level of 2'5' oligoadenylatesynthetase activity induction in general correlates with antiproliferative and pronounced antiviral activity of interferons, besides that, the earlier (by 11 hours) induction of the enzyme activity by beta-interferon correlates with more rapid expression of antiproliferative effects by this interferon in comparison with that of alpha-interferon, the latter inducing the peak of enzyme activity by 24 hours.
Mol Gen Mikrobiol Virusol 1986 Apr
PMID:[Antiviral and antiproliferative activity of human interferons and their induction of 2',5'-oligoadenylate synthetase]. 243 19

Prolonged alpha/beta interferon (IFN-alpha/beta) treatment of NIH 3T3 cells transformed by a long terminal repeat-activated Ha-ras proto-oncogene resulted in revertants that maintained a nontransformed phenotype long after IFN treatment had been discontinued. Cloned persistent revertants (PRs) produced large amounts of the ras-encoded p21 and were refractile to transformation by EJras DNA and by transforming retroviruses which carried the v-Ha-ras, v-Ki-ras, v-abl, or v-fes oncogene. Transient treatment either in vitro or in vivo with cytidine analogs that alter gene expression by inhibiting DNA methylation resulted in transformation of PR, but not of NIH 3T3, cells. The PR retransformants reverted again with IFN, suggesting that DNA methylation is involved in IFN-induced persistent reversion.
Mol Cell Biol 1987 Jun
PMID:Interferon-induced revertants of ras-transformed cells: resistance to transformation by specific oncogenes and retransformation by 5-azacytidine. 243 4


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