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Akinori Ishimoto - One of the best experts on this subject based on the ideXlab platform.

  • identification of a novel mammary cell line specific enhancer Element in the long terminal repeat of mouse mammary tumor virus which interacts with its Hormone Responsive Element
    Journal of Virology, 1991
    Co-Authors: Shinichi Yanagawa, H Tanaka, Akinori Ishimoto
    Abstract:

    We analyzed the long terminal repeat (LTR) of mouse mammary tumor virus for sequences that influence its promoter activity by using the chloramphenicol acetyltransferase assay. A series of LTR deletion mutants and recombinants between LTR and simian virus 40 regulatory sequences were used for these studies. Through transfection experiments in three different human cell lines (T47D, MCF-7, and HeLa), we identified a novel mammary cell line-specific enhancer Element on a 98-bp BanII fragment (from position -1075 to -978 upstream of the start site of transcription) which interacts with the Hormone-Responsive Element of LTR. We also identified nuclear factors that specifically interacted with this BanII fragment in the nuclear extract from the mammary tumor cell line, T47D, but not from the HeLa cell line.

Edwin Milgrom - One of the best experts on this subject based on the ideXlab platform.

  • characterization of the Hormone Responsive Element involved in the regulation of the progesterone receptor gene
    The EMBO Journal, 1991
    Co-Authors: Jeanfrancois Savouret, A Bailly, M Misrahi, Claudine Rauch, G Redeuilh, Anne Chauchereau, Edwin Milgrom
    Abstract:

    The transcription of the progesterone receptor gene is induced by estrogens and decreased by progestins. Studies were performed to define the regions of the gene and the molecular mechanisms involved. No hormonal regulation could be observed using 5' flanking regions of the gene up to -2762 in front of a heterologous gene. Estrogen and progestin regulation could be observed only when using fragments of the gene extending down to +788. Progressive deletions from the 5' and 3' ends, site-directed mutagenesis and DNase protection experiments with purified estrogen receptor suggested that the biologically active estrogen Responsive Element (ERE) is present at +698/+723, overlapping the initiation of translation. An oligonucleotide was synthesized bearing this ERE and shown to impart estrogen inducibility to a heterologous gene. Its regulation by anti-estrogens corresponded to that of the in situ progesterone receptor gene since tamoxifen was a partial agonist whereas ICI 164384 was a full antagonist. This ERE also mediated down-regulation by progestins in the presence of the progesterone receptor, even though it has no progesterone receptor binding ability. DNase footprinting showed that this effect was not due to a decrease of estrogen receptor affinity for the ERE in the presence of progesterone receptor. Finally, use of deletion mutants of the progesterone receptor showed that the steroid binding and the DNA binding domains were necessary for down-regulation whereas deletions of various parts of the N-terminal domain were without effect.

Desanka Bogojevic - One of the best experts on this subject based on the ideXlab platform.

  • association of the glucocorticoid receptor with stat3 c ebpβ and the Hormone Responsive Element within the rat haptoglobin gene promoter during the acute phase response
    Iubmb Life, 2010
    Co-Authors: Jelena Arambasic, Aleksandra Uskokovic, Desanka Bogojevic, Svetlana Ivanovicmatic, Goran Poznanovic, Mirjana Mihailovic, Ilijana Grigorov
    Abstract:

    Upregulation of haptoglobin (Hp) expression in the rat during the acute phase (AP) response is the result of synergistic effects of IL-6–, IL-1β–, and corticosterone-activated signaling pathways. IL-6 signaling terminates in cis–trans interactions of the Hp gene Hormone-Responsive Element (HRE) with transcription factors STAT3 and C/EBPβ. The aim of this study was to examine the unresolved molecular mechanism of glucocorticoid action. A 3-fold rise in serum corticosterone at 2 and 4 h of the AP response induced by turpentine administration preceded a 2.3-fold increase in the rate of Hp gene transcription at 12 h that was accompanied by a 4.8-fold increase in glucocorticoid receptor (GR), the appearance of an 86-kDa STAT3 isoform and 3.9-, 1.9-, and 1.7-fold increased amounts of 91-kDa STAT3, 35- and 42-kDa C/EBPβ isoforms in the nucleus. These events resulted in 4.6- and 2.5-fold increased Hp levels in the liver and serum at 24 h. HRE affinity chromatography and immunoblot analysis revealed that maximal occupancy of the HRE with GR, STAT3, and C/EBPβ at 12 h correlated with increased transcriptional activity of the Hp gene. Coimmunoprecipitation experiments showed that activated GR established de novo interaction with STAT3 isoforms while GR–C/EBPβ interactions observed during basal transcription increased during the AP response. Computer analysis of the HRE disclosed two potential GR-binding sites: one overlapping STAT3, another adjacent to a C/EBPβ-binding site. This finding and the experimental results suggest that activated GR through direct interactions with STAT3 and C/EBPβ, participates in Hp gene upregulation as a transcriptional coactivator. © 2010 IUBMB IUBMB Life, 62(2): 227–236, 2010

  • the effect of o glcnac glycosylation of rat liver nucleoproteins on their acute phase dependent binding ability to the Hormone Responsive Element of the haptoglobin gene
    General Physiology and Biophysics, 2004
    Co-Authors: Ilijana Grigorov, Ivana Cvetkovic, Tanja Milosavljevic, Aleksandra Uskokovic, Desanka Bogojevic, Svetlana Ivanovicmatic, Goran Poznanovic, M Petrovic
    Abstract:

    We examined whether the transcriptional activation of the rat hap- toglobin (Hp) gene during the acute phase (AP) response reflects the O-linked N-acetylglucosamine (O-GlcNAc) status of liver nucleoproteins (NPs) and their binding for the Hormone Responsive Element (HRE). After deglycosylationwith N- acetylglucosaminidase of the O-GlcNAc glycoproteins obtained by WGA, anity chromatography and South-Western analysis, it was observed that only increased HRE binding ability of p64/p70 in control and p51 obtained from turpentine- treated rats can be directly attributed to the presence of O-GlcNAc residues. Therefore, expression of the rat Hp gene could be controlled by this modication of certain trans-acting NPs.

  • p53 like protein binding affinity to the Hormone Responsive Element of the haptoglobin gene in fetal rat liver
    Cell Biology International, 2002
    Co-Authors: Desanka Bogojevic, M Petrovic, Mirjana Mihailovic
    Abstract:

    In order to identify nucleoproteins involved in transcriptional regulation of the haptoglobin (Hp) gene, fetal rat livers of dams exposed to inflammation on day 19 of pregnancy were used. Previously observed acute phase-dependent elevation of Hp gene transcriptional activity in prenatal liver was accompanied by increased binding affinities of several fetal soluble nucleoproteins and the Hormone response Element (RE) of the Hp gene (-170/-56). One of these proteins, a hepatic nucleoprotein of 53 kDa, was identified by Western blotting analysis as a protein within the same molecular mass and epitopes as transcription factor p53. Also, in vitro phosphorylation experiments revealed that the examined fetal nucleoprotein could be liable to the same phosphorylative post-translational modification as p53. The obtained results suggest that the fetal 53 kDa-nucleoprotein could be a homologue of transcription factor p53, participating in the transcriptional modulation of the Hp gene throughout prenatal hepatic development.

Mirjana Mihailovic - One of the best experts on this subject based on the ideXlab platform.

  • association of the glucocorticoid receptor with stat3 c ebpβ and the Hormone Responsive Element within the rat haptoglobin gene promoter during the acute phase response
    Iubmb Life, 2010
    Co-Authors: Jelena Arambasic, Aleksandra Uskokovic, Desanka Bogojevic, Svetlana Ivanovicmatic, Goran Poznanovic, Mirjana Mihailovic, Ilijana Grigorov
    Abstract:

    Upregulation of haptoglobin (Hp) expression in the rat during the acute phase (AP) response is the result of synergistic effects of IL-6–, IL-1β–, and corticosterone-activated signaling pathways. IL-6 signaling terminates in cis–trans interactions of the Hp gene Hormone-Responsive Element (HRE) with transcription factors STAT3 and C/EBPβ. The aim of this study was to examine the unresolved molecular mechanism of glucocorticoid action. A 3-fold rise in serum corticosterone at 2 and 4 h of the AP response induced by turpentine administration preceded a 2.3-fold increase in the rate of Hp gene transcription at 12 h that was accompanied by a 4.8-fold increase in glucocorticoid receptor (GR), the appearance of an 86-kDa STAT3 isoform and 3.9-, 1.9-, and 1.7-fold increased amounts of 91-kDa STAT3, 35- and 42-kDa C/EBPβ isoforms in the nucleus. These events resulted in 4.6- and 2.5-fold increased Hp levels in the liver and serum at 24 h. HRE affinity chromatography and immunoblot analysis revealed that maximal occupancy of the HRE with GR, STAT3, and C/EBPβ at 12 h correlated with increased transcriptional activity of the Hp gene. Coimmunoprecipitation experiments showed that activated GR established de novo interaction with STAT3 isoforms while GR–C/EBPβ interactions observed during basal transcription increased during the AP response. Computer analysis of the HRE disclosed two potential GR-binding sites: one overlapping STAT3, another adjacent to a C/EBPβ-binding site. This finding and the experimental results suggest that activated GR through direct interactions with STAT3 and C/EBPβ, participates in Hp gene upregulation as a transcriptional coactivator. © 2010 IUBMB IUBMB Life, 62(2): 227–236, 2010

  • p53 like protein binding affinity to the Hormone Responsive Element of the haptoglobin gene in fetal rat liver
    Cell Biology International, 2002
    Co-Authors: Desanka Bogojevic, M Petrovic, Mirjana Mihailovic
    Abstract:

    In order to identify nucleoproteins involved in transcriptional regulation of the haptoglobin (Hp) gene, fetal rat livers of dams exposed to inflammation on day 19 of pregnancy were used. Previously observed acute phase-dependent elevation of Hp gene transcriptional activity in prenatal liver was accompanied by increased binding affinities of several fetal soluble nucleoproteins and the Hormone response Element (RE) of the Hp gene (-170/-56). One of these proteins, a hepatic nucleoprotein of 53 kDa, was identified by Western blotting analysis as a protein within the same molecular mass and epitopes as transcription factor p53. Also, in vitro phosphorylation experiments revealed that the examined fetal nucleoprotein could be liable to the same phosphorylative post-translational modification as p53. The obtained results suggest that the fetal 53 kDa-nucleoprotein could be a homologue of transcription factor p53, participating in the transcriptional modulation of the Hp gene throughout prenatal hepatic development.

Ilijana Grigorov - One of the best experts on this subject based on the ideXlab platform.

  • association of the glucocorticoid receptor with stat3 c ebpβ and the Hormone Responsive Element within the rat haptoglobin gene promoter during the acute phase response
    Iubmb Life, 2010
    Co-Authors: Jelena Arambasic, Aleksandra Uskokovic, Desanka Bogojevic, Svetlana Ivanovicmatic, Goran Poznanovic, Mirjana Mihailovic, Ilijana Grigorov
    Abstract:

    Upregulation of haptoglobin (Hp) expression in the rat during the acute phase (AP) response is the result of synergistic effects of IL-6–, IL-1β–, and corticosterone-activated signaling pathways. IL-6 signaling terminates in cis–trans interactions of the Hp gene Hormone-Responsive Element (HRE) with transcription factors STAT3 and C/EBPβ. The aim of this study was to examine the unresolved molecular mechanism of glucocorticoid action. A 3-fold rise in serum corticosterone at 2 and 4 h of the AP response induced by turpentine administration preceded a 2.3-fold increase in the rate of Hp gene transcription at 12 h that was accompanied by a 4.8-fold increase in glucocorticoid receptor (GR), the appearance of an 86-kDa STAT3 isoform and 3.9-, 1.9-, and 1.7-fold increased amounts of 91-kDa STAT3, 35- and 42-kDa C/EBPβ isoforms in the nucleus. These events resulted in 4.6- and 2.5-fold increased Hp levels in the liver and serum at 24 h. HRE affinity chromatography and immunoblot analysis revealed that maximal occupancy of the HRE with GR, STAT3, and C/EBPβ at 12 h correlated with increased transcriptional activity of the Hp gene. Coimmunoprecipitation experiments showed that activated GR established de novo interaction with STAT3 isoforms while GR–C/EBPβ interactions observed during basal transcription increased during the AP response. Computer analysis of the HRE disclosed two potential GR-binding sites: one overlapping STAT3, another adjacent to a C/EBPβ-binding site. This finding and the experimental results suggest that activated GR through direct interactions with STAT3 and C/EBPβ, participates in Hp gene upregulation as a transcriptional coactivator. © 2010 IUBMB IUBMB Life, 62(2): 227–236, 2010

  • the effect of o glcnac glycosylation of rat liver nucleoproteins on their acute phase dependent binding ability to the Hormone Responsive Element of the haptoglobin gene
    General Physiology and Biophysics, 2004
    Co-Authors: Ilijana Grigorov, Ivana Cvetkovic, Tanja Milosavljevic, Aleksandra Uskokovic, Desanka Bogojevic, Svetlana Ivanovicmatic, Goran Poznanovic, M Petrovic
    Abstract:

    We examined whether the transcriptional activation of the rat hap- toglobin (Hp) gene during the acute phase (AP) response reflects the O-linked N-acetylglucosamine (O-GlcNAc) status of liver nucleoproteins (NPs) and their binding for the Hormone Responsive Element (HRE). After deglycosylationwith N- acetylglucosaminidase of the O-GlcNAc glycoproteins obtained by WGA, anity chromatography and South-Western analysis, it was observed that only increased HRE binding ability of p64/p70 in control and p51 obtained from turpentine- treated rats can be directly attributed to the presence of O-GlcNAc residues. Therefore, expression of the rat Hp gene could be controlled by this modication of certain trans-acting NPs.