Association of interleukin-1-induced, NFκB DNA-binding activity with collagenase gene expression in human gingival fibroblasts

1996 ◽  
Vol 41 (5) ◽  
pp. 461-468 ◽  
Author(s):  
M. Tewari ◽  
O.C. Tuncay ◽  
A. Milchman ◽  
P.J. Reddy ◽  
C.D. Reddy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Interleukin 1 ◽  
Binding Activity ◽  
Human Gingival Fibroblasts ◽  
Gingival Fibroblasts ◽  
Dna Binding Activity ◽  
Collagenase Gene

Extinction of insulin gene expression in hybrids between beta cells and fibroblasts is accompanied by loss of the putative beta-cell-specific transcription factor IEF1

1991 ◽  
Vol 11 (3) ◽  
pp. 1547-1552
Author(s):  
D Leshkowitz ◽  
M D Walker
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Binding Activity ◽  
Insulin Gene ◽  
Hybrid Cells ◽  
Dna Binding Activity ◽  
Insulin Producing Cells ◽  
Insulin Gene Expression ◽  
Insulinoma Cells

Insulin-producing cells and fibroblasts were fused to produce hybrid lines. In hybrids derived from both hamster and rat insulinoma cells, no insulin mRNA could be detected in any of seven lines examined by Northern (RNA) analysis despite the presence in each line of the insulin genes of both parental cells. Hybrid cells were transfected with recombinant chloramphenicol acetyltransferase plasmids containing defined segments of the rat insulin I gene 5' flank. We observed no transcriptional activity of the intact insulin enhancer or of IEB2, a critical cis-acting element of the insulin enhancer. IEB2 has previously been shown to interact in vitro with IEF1, a DNA-binding activity observed selectively in insulin-producing cells. Hybrid cells showed no detectable IEF1 activity. Furthermore, the insulin enhancer was unable to reduce transcription directed by the Moloney sarcoma virus enhancer in a double-enhancer construct. Thus, extinction of insulin gene expression in the hybrids apparently does not operate through a direct action of repressors on the insulin enhancer; rather, extinction is accompanied by, and may be caused by, reduced DNA-binding activity of the putative transcriptional activator IEF1.

scholarly journals Overexpression of mitogen-activated protein kinase (ERK1) enhances T- cell cytokine gene expression: role of AP1, NF-AT, and NF-KB

Blood ◽  
1993 ◽  
Vol 82 (8) ◽  
pp. 2470-2477 ◽  
Author(s):  
JH Park ◽  
L Levitt
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Dna Binding ◽  
Map Kinase ◽  
Binding Activity ◽  
Cytokine Gene Expression ◽  
Cytokine Gene ◽  
Dna Binding Activity ◽  
Mitogen Activated Protein

Abstract Transfected Jurkat cells overexpressing extracellular signal-regulated kinase (ERK1), also referred to as mitogen-activated protein (MAP) kinase, were selected by Western blotting assay using anti-ERK1 and antiphosphotyrosine antibodies in combination with a functional MAP kinase assay. We then asked whether enhanced ERK1 expression had any effect on induction of T-cell cytokine genes. The results show that overexpression of ERK1 enhances expression of T-cell interleukin-2 (IL- 2), IL-3, and granulocyte-macrophage colony-stimulating factor mRNA; no change was seen in expression of the alpha-actin gene. DNA-binding activities of the transcription factors AP1, NF-AT, and NF-kB were specifically increased twofold to fourfold in ERK1-overexpressing clones relative to nontransformed or vector-transformed cells, whereas no enhancement of CK1-CK2 protein DNA binding activity was detected after ERK1 overexpression. Additionally, increased NF-AT DNA binding activity was associated with functional enhancement of NF-AT transactivating activity in ERK1-overexpressing cells. These results provide direct evidence for the role of MAP kinase in the regulation of cytokine gene expression and indicate that such regulation is likely mediated through the enhanced DNA binding activity of specific nuclear transcription factors.

scholarly journals Signaling mechanisms regulating bombesin-mediated AP-1 gene induction in the human gastric cancer SIIA

2000 ◽  
Vol 279 (2) ◽  
pp. C326-C334 ◽  
Author(s):  
Hong Jin Kim ◽  
B. Mark Evers ◽  
David A. Litvak ◽  
Mark R. Hellmich ◽  
Courtney M. Townsend
Keyword(s):  
Gene Expression ◽  
Gastric Cancer ◽  
Protein Kinase ◽  
Dna Binding ◽  
Signaling Pathways ◽  
Binding Activity ◽  
Human Gastric Cancer ◽  
Rapid Induction ◽  
Dna Binding Activity ◽  
Jun B

The hormone bombesin (BBS) and its mammalian equivalent gastrin-releasing peptide (GRP) act through specific GRP receptors (GRP-R) to affect multiple cellular functions in the gastrointestinal tract; the intracellular signaling pathways leading to these effects are not clearly defined. Previously, we demonstrated that the human gastric cancer SIIA possesses GRP-R and that BBS stimulates activator protein-1 (AP-1) gene expression. The purpose of our present study was to determine the signaling pathways leading to AP-1 induction in SIIA cells. A rapid induction of c- jun and jun-B gene expression was noted after BBS treatment; this effect was blocked by specific GRP-R antagonists, indicating that BBS is acting through the GRP-R. The signaling pathways leading to increased AP-1 gene expression were delineated using phorbol 12-myristate 13-acetate (PMA), which stimulates protein kinase C (PKC)-dependent pathways, by forskolin (FSK), which stimulates protein kinase A (PKA)-dependent pathways, and by the use of various protein kinase inhibitors. Treatment with PMA stimulated AP-1 gene expression and DNA binding activity similar to the effects noted with BBS; FSK stimulated jun-B expression but produced only minimal increases of c- jun mRNA and AP-1 binding activity. Pretreatment of SIIA cells with either H-7 or H-8 (primarily PKC inhibitors) inhibited the induction of c- jun and jun-B mRNAs in response to BBS, whereas H-89 (PKA inhibitor) exhibited only minimal effects. Pretreatment with tyrphostin-25, a protein tyrosine kinase (PTK) inhibitor, attenuated the BBS-mediated induction of c- jun and jun-B, but the effect was not as pronounced as with H-7. Collectively, our results demonstrate that BBS acts through its receptor to produce a rapid induction of both c- jun and jun-B mRNA and AP-1 DNA binding activity in the SIIA human gastric cancer. Moreover, this induction of AP-1, in response to BBS, is mediated through both PKC- and PTK-dependent signal transduction pathways with only minimal involvement of PKA.

Efficient transcription of the glycolytic gene ADH1 and three translational component genes requires the GCR1 product, which can act through TUF/GRF/RAP binding sites

1990 ◽  
Vol 10 (2) ◽  
pp. 859-862
Author(s):  
G M Santangelo ◽  
J Tornow
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Dna Binding ◽  
Binding Sites ◽  
Binding Activity ◽  
Heterologous Gene ◽  
Dna Binding Activity ◽  
Glycolytic Gene

Glycolytic gene expression in Saccharomyces cerevisiae is thought to be activated by the GCR and TUF proteins. We tested the hypothesis that GCR function is mediated by TUF/GRF/RAP binding sites (UASRPG elements). We found that UASRPG-dependent activation of a heterologous gene and transcription of ADH1, TEF1, TEF2, and RP59 were sensitive to GCR1 disruption. GCR is not required for TUF/GRF/RAP expression or in vitro DNA-binding activity.

NF-kB as a Regulator of FA/BRCA Gene Expression in Multiple Myeloma.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3508-3508
Author(s):  
Vasco A. Oliveira ◽  
Linda Mathews ◽  
Danielle Yarde ◽  
Xingyu Wang ◽  
David Boulware ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Drug Resistance ◽  
Dna Binding ◽  
Cell Lines ◽  
Myeloma Cell ◽  
Binding Activity ◽  
Acquired Drug Resistance ◽  
Brca Gene ◽  
Dna Binding Activity

Abstract Results to date argue compellingly that disruption of FA/BRCA gene expression plays a pivotal role in human somatic carcinogenesis. Melphalan, a DNA cross-linker, is one of the most widely used and effective drugs in the treatment of multiple myeloma (MM). Although most patients respond to standard and high dose melphalan, eventually patients acquire resistance and develop progressive disease. In 1991, our laboratory reported that acquired resistance in a human myeloma cell line was associated with reduced DNA crosslinks, elevated glutathione levels, and increased radiation survival (Cancer Res. 5:993; 1991). Most recently, we reported that the melphalan-resistant myeloma cell lines, 8226/LR5 and U266/LR6, showed a significant increase in several FA/BRCA genes compared to drug-sensitive cells, and that enhanced interstrand crosslink (ICL) repair via this signaling pathway contributes to acquired drug resistance in melphalan resistant cell lines (Blood 10:698; 2005). Here, we report that IKKa is constitutively phosphorylated in unstimulated 8226/LR5 cells, but not in melphalan-sensitive control cells. The specific phosphorylation of IKKa leads to an increase in basal NF-kB DNA binding activity, and 8226/LR5 cells are found to be markedly sensitive to BMS-345541 (a highly selective inhibitor of IkB) relative to control cells. Importantly, a cytotoxic dose of BMS-345541 induces a dramatic decrease in FA/BRCA gene expression, and a concomitant inhibition of NF-kB DNA binding activity in both 8226/S and 8226/LR5 cells. Furthermore, we show that 8226/LR5 cells experience the highest degree of direct binding between FANCD2 promoter and NF-kB/Rel family members, which, in turn, leads to an increase in basal FANCD2-specific NF-kB activity. Small-interfering RNA (siRNA)-mediated depletion of RelB and p50, but not other NF-kB subunits, in 8226 cells results in impaired NF-kB binding activity, and visible decrease in FANCD2 protein expression. Studies designed to dissect the role of NF-kB in acquired melphalan resistance are in progress, and the results will be presented. Our findings suggest that NF-kB functions as a regulator of FA/BRCA expression, and that this pathway represents a new target for preventing acquired drug resistance in myeloma patients.

scholarly journals Serum amyloid A gene expression under acute-phase conditions involves participation of inducible C/EBP-beta and C/EBP-delta and their activation by phosphorylation.

1994 ◽  
Vol 14 (6) ◽  
pp. 4324-4332 ◽  
Author(s):  
A Ray ◽  
B K Ray
Keyword(s):  
Gene Expression ◽  
Dna Binding ◽  
Serum Amyloid A ◽  
Binding Activity ◽  
Serum Amyloid ◽  
Phosphatase Inhibitors ◽  
Amyloid A ◽  
Dna Binding Activity ◽  
Inflammatory Stimuli

Serum amyloid A (SAA) is a plasma protein whose synthesis is markedly increased in the liver during the inflammatory process. Previous analysis of SAA promoter function implicated the involvement of the CCAAT/enhancer-binding protein (C/EBP) in controlling this process. In this study, using antibodies against three C/EBP isoforms in DNA-binding and Western blot (immunoblot) assays, we found that in response to inflammatory signals, both C/EBP-delta and C/EBP-beta are induced and that their interactions with the SAA promoter element are necessary for the increased SAA gene expression. Cotransfections of liver cells with an SAA promoter-linked reporter chloramphenicol acetyltransferase gene and murine sarcoma virus-expressed C/EBP-delta or C/EBP-beta confirm such phenomena. The increased transactivating ability in the presence of the cellular phosphatase inhibitors okadaic acid and sodium orthovanadate, coupled with the observation that dephosphorylation severely inhibits the DNA-binding ability in vitro, implicates a role of phosphorylation in the regulation of the activities of the C/EBP-delta isoform. Consistent with these findings, we have detected higher levels of DNA-binding activity of C/EBP-delta prepared from cells treated with phosphatase inhibitors. We also present evidence that C/EBP-delta is a phosphoprotein. These results suggest that C/EBP-delta is regulated by phosphorylation and, in conjunction with C/EBP-beta, is one of the major proteins responsible for the increased transcription of the SAA gene in response to inflammatory stimuli.

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