scholarly journals Cu,Zn-superoxide dismutase deficiency in mice leads to organ-specific increase in oxidatively damaged DNA and NF-κB1 protein activity.

2010 ◽  
Vol 57 (4) ◽  
Author(s):  
Agnieszka Siomek ◽  
Kamil Brzoska ◽  
Barbara Sochanowicz ◽  
Daniel Gackowski ◽  
Rafal Rozalski ◽  
...  
Keyword(s):  
Dna Damage ◽  
Superoxide Dismutase ◽  
Dna Binding ◽  
Urinary Excretion ◽  
Oxidative Dna Damage ◽  
Binding Activity ◽  
Wild Type ◽  
Dna Binding Activity ◽  
Organ Specific ◽  
Damaged Dna

Earlier experimental studies have demonstrated that: i) Cu,Zn-superoxide dismutase deficiency leads to oxidative stress and carcinogenesis; ii) dysregulation of NF-κB pathway can mediate a wide variety of diseases, including cancer. Therefore, we decided, for the first time, to examine the level of oxidative DNA damage and the DNA binding activity of NF-κB proteins in SOD1 knockout, heterozygous and wild-type mice. Two kinds of biomarkers of oxidatively damaged DNA: urinary excretion of 8-oxodG and 8-oxoGua, and the level of oxidatively damaged DNA were analysed using HPLC-GC-MS and HPLC-EC. The DNA binding activity of p50 and p65 proteins in a nuclear extracts was assessed using NF-κB p50/p65 EZ-TFA transcription factor assay. These parameters were determined in the brain, liver, kidney and urine of SOD1 knockout, heterozygous and wild-type mice. The level of 8-oxodG in DNA was higher in the liver and kidney of knockout mice than in wild type. No differences were found in urinary excretion of 8-oxoGua and 8-oxodG between wild type and the SOD1-deficient animals. The activity of the p50 protein was higher in the kidneys, but surprisingly not in the livers of SOD1-deficient mice, whereas p65 activity did not show any variability. Our results indicate that in Cu,Zn-SOD-deficient animals the level of oxidative DNA damage and NF-κB1 activity are elevated in certain organs only, which may provide some explanation for organ-specific ROS-induced carcinogenesis.

scholarly journals CP-31398 Restores DNA-binding Activity to Mutant p53in Vitrobut Does Not Affect p53 Homologs p63 and p73

2004 ◽  
Vol 279 (44) ◽  
pp. 45887-45896 ◽  
Author(s):  
Mark J. Demma ◽  
Serena Wong ◽  
Eugene Maxwell ◽  
Bimalendu Dasmahapatra
Keyword(s):  
Dna Binding ◽  
Mammalian Cells ◽  
P53 Protein ◽  
Binding Activity ◽  
Mutant P53 ◽  
Dependent Manner ◽  
Wild Type ◽  
Dna Binding Activity

The p53 protein plays a major role in the maintenance of genome stability in mammalian cells. Mutations of p53 occur in over 50% of all cancers and are indicative of highly aggressive cancers that are hard to treat. Recently, there has been a high degree of interest in therapeutic approaches to restore growth suppression functions to mutant p53. Several compounds have been reported to restore wild type function to mutant p53. One such compound, CP-31398, has been shown effectivein vivo, but questions have arisen to whether it actually affects p53. Here we show that mutant p53, isolated from cells treated with CP-31398, is capable of binding to p53 response elementsin vitro. We also show the compound restores DNA-binding activity to mutant p53 in cells as determined by a chromatin immunoprecipitation assay. In addition, using purified p53 core domain from two different hotspot mutants (R273H and R249S), we show that CP-31398 can restore DNA-binding activity in a dose-dependent manner. Using a quantitative DNA binding assay, we also show that CP-31398 increases significantly the amount of mutant p53 that binds to cognate DNA (Bmax) and its affinity (Kd) for DNA. The compound, however, does not affect the affinity (Kdvalue) of wild type p53 for DNA and only increasesBmaxslightly. In a similar assay PRIMA1 does not have any effect on p53 core DNA-binding activity. We also show that CP-31398 had no effect on the DNA-binding activity of p53 homologs p63 and p73.

scholarly journals Redox Regulation of Adenovirus-Induced AP-1 Activation by Overexpression of Manganese-Containing Superoxide Dismutase

2002 ◽  
Vol 76 (1) ◽  
pp. 355-363 ◽  
Author(s):  
Hannah J. Zhang ◽  
Victoria J. Drake ◽  
Linjing Xu ◽  
Jianfang Hu ◽  
Frederick E. Domann ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Dna Binding ◽  
Redox Regulation ◽  
Recombinant Adenovirus ◽  
Redox Status ◽  
Binding Activity ◽  
Dna Binding Activity ◽  
Promising Tool ◽  
Gel Shift Assay ◽  
Intracellular Redox Status

ABSTRACT Adenovirus gene therapy is a promising tool in the clinical treatment of many genetic and acquired diseases. However, it has also caused pathogenic effects in organs such as the liver. The redox-sensitive transcription factors AP-1 and NF-κB have been implicated in these effects. To study the mechanisms of adenovirus-mediated AP-1 and NF-κB activation and the possible involvement of oxidative stress in adenovirus transduction, rats were injected with either replication-defective recombinant adenovirus with DNA containing the cytomegalovirus promoter region only (AdCMV), adenovirus containing human manganese-containing superoxide dismutase (MnSOD) cDNA (AdMnSOD), or vehicle. Compared to vehicle and AdCMV transduction, MnSOD gene transfer yielded a fivefold increase in liver MnSOD activity 7 days postinjection. Gel shift assay showed that AdCMV transduction induced DNA binding activity for AP-1 but not NF-κB. MnSOD overexpression abolished this activation. Western blotting analysis of c-Fos and c-Jun suggested that up-regulation of c-fos and c-jun gene expression does not directly contribute to the induction of AP-1 activation. Glutathione/glutathione disulfide ratios were decreased by adenovirus transduction and restored by MnSOD overexpression. The AP-1 binding activity that was induced by AdCMV was decreased by immunoprecipitation of Ref-1 protein. Ref-1 involvement was confirmed by restoration of AP-1 binding activity after the immunoprecipitated Ref-1 protein had been added back. AP-1 DNA binding activity was also elevated in control and AdMnSOD-injected rats after addition of the immunoprecipitated Ref-1 protein. These data indicate that cellular transduction by recombinant adenovirus stimulates AP-1 DNA binding activity. Furthermore, our results suggest that MnSOD overexpression decreases AP-1 DNA binding activity by regulating intracellular redox status, with the possible involvement of Ref-1 in this redox-sensitive pathway.

Analysis Of E2A Point Mutations In B Cell Leukemia

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 4850-4850
Author(s):  
Eroica Soans ◽  
John K Choi
Keyword(s):  
Dna Binding ◽  
B Cell ◽  
Binding Activity ◽  
Luciferase Reporter ◽  
Reporter Assay ◽  
Cell Leukemia ◽  
Wild Type ◽  
Dna Binding Activity ◽  
E Box ◽  
B Cell Leukemia

Abstract Introduction TCF3 encodes for E2A protein, which belongs to the helix loop helix transcription factor family. E2A activates transcription of downstream genes by binding to E-box motifs as a homo or hetero dimer. E2A plays an important role in B lymphocyte development. Therefore deletion or mutations in TCF3 or even lowered activity of E2A are causes of B cell leukemia and lymphomas. Recently, three mutations V557E, D561E and N551K in E2A were isolated in Burkitt’s lymphoma (Schmitz, Young et al. 2012). The first two mutations are present in the homo dimerization region of E2A while N551K is present in the DNA binding region. Though the paper enumerated role of TCF3 in Burkitt’s lymphoma but the significance of these TCF3 mutations or mechanism needed further characterization. We hypothesized that these TCF3 mutations have an alternate mechanism as compared to wild type TCF3 and therefore may affect B cell development. Methods We characterized three TCF3 mutants by cloning them into in MIGR1 backbone using TOPO cloning. E2A activity was measured using an E2A-specific luciferase reporter assay in 293T cells. DNA binding activity was measured using a DNA protein binding colorimetric assay. Results V557E and D561E mutants have lower activity as compared to wild type E2A as studied using E2A-specific luciferase reporter assay; while N551K showed no activity in the same assay as compared to wild type E2A activity. Similarly V557E and D561 form weaker bonds with the E box motifs while N551K showed no DNA binding activity as studied using colorimetric DNA-protein binding assay. The plasmid expressions were verified using western blot analysis. Conclusion Our findings suggest mutations V557E and D561E may follow a similar pathway as wild-type E2A but have lower activity. The N551K mutation has an alternate pathway to wild type TCF3 that may impact B cell proliferation, survival and development. Disclosures: No relevant conflicts of interest to declare.

scholarly journals The Single-Strand DNA Binding Activity of Human PC4 Prevents Mutagenesis and Killing by Oxidative DNA Damage

2004 ◽  
Vol 24 (13) ◽  
pp. 6084-6093 ◽  
Author(s):  
Jen-Yeu Wang ◽  
Altaf Hossain Sarker ◽  
Priscilla K. Cooper ◽  
Michael R. Volkert
Keyword(s):  
Dna Damage ◽  
Oxidative Dna Damage ◽  
Binding Activity ◽  
Single Strand ◽  
Physical Interaction ◽  
Ssdna Binding ◽  
Dna Binding Activity ◽  
Resistance Pathway ◽  
Domain Of Unknown Function ◽  
Human Proteins

ABSTRACT Human positive cofactor 4 (PC4) is a transcriptional coactivator with a highly conserved single-strand DNA (ssDNA) binding domain of unknown function. We identified PC4 as a suppressor of the oxidative mutator phenotype of the Escherichia coli fpg mutY mutant and demonstrate that this suppression requires its ssDNA binding activity. Saccharomyces cerevisiae mutants lacking their PC4 ortholog Sub1 are sensitive to hydrogen peroxide and exhibit spontaneous and peroxide-induced hypermutability. PC4 expression suppresses the peroxide sensitivity of the yeast sub1Δ mutant, suggesting that the human protein has a similar function. A role for yeast and human proteins in DNA repair is suggested by the demonstration that Sub1 acts in a peroxide resistance pathway involving Rad2 and by the physical interaction of PC4 with the human Rad2 homolog XPG. We show that XPG recruits PC4 to a bubble-containing DNA substrate with a resulting displacement of XPG and formation of a PC4-DNA complex. We discuss the possible requirement for PC4 in either global or transcription-coupled repair of oxidative DNA damage to mediate the release of XPG bound to its substrate.

scholarly journals Accumulation of manganese superoxide dismutase under metal-depleted conditions: proposed role for zinc ions in cellular redox balance

2004 ◽  
Vol 377 (1) ◽  
pp. 241-248 ◽  
Author(s):  
Kaoru OTSU ◽  
Yoshitaka IKEDA ◽  
Junichi FUJII
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Dna Binding ◽  
Manganese Superoxide Dismutase ◽  
Binding Activity ◽  
Rat Liver Mitochondria ◽  
Zinc Ions ◽  
Dna Binding Activity ◽  
Manganese Superoxide ◽  
In Cells

A diet low in copper results in increased levels of MnSOD (manganese superoxide dismutase), a critical antioxidative enzyme conferring protection against oxidative stress, in rat liver mitochondria. The mechanism for this was investigated using cultured HepG2 cells, a human hepatocellular carcinoma-derived line. MnSOD activity increased 5–7-fold during incubation in a medium supplemented with metal-depleted fetal bovine serum, with a corresponding elevation of its mRNA levels. Metal depletion also decreased CuZnSOD and glutathione peroxidase levels to approx. 70–80% of baseline. When zinc ions were added to the medium at micromolar levels, MnSOD accumulation was suppressed; however, copper ions had essentially no effect on MnSOD expression. Since the intracellular redox status was shifted to a more oxidized state by metal depletion, we examined the DNA-binding activity of NF-κB (nuclear factor-κB), an oxidative stress-sensitive transactivating factor that plays a primary role in MnSOD induction. A gel shift assay indicated that the DNA-binding activity of NF-κB was increased in cells maintained in metal-depleted culture, suggesting the involvement of the transactivating function of NF-κB in this induction. This was further supported by the observation that curcumin suppressed both the DNA-binding activity of NF-κB and the induction of MnSOD mRNA in cells cultivated under metal-depleted conditions. These results suggest that the level of zinc, rather than copper, is a critical regulatory factor in MnSOD expression. It is possible that a deficiency of zinc in the low-copper diet may be primarily involved in MnSOD induction.

scholarly journals Structure analysis of FAAP24 reveals single-stranded DNA-binding activity and domain functions in DNA damage response

Cell Research ◽  
2013 ◽  
Vol 23 (10) ◽  
pp. 1215-1228 ◽  
Author(s):  
Yucai Wang ◽  
Xiao Han ◽  
Fangming Wu ◽  
Justin W Leung ◽  
Megan G Lowery ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Binding ◽  
Structure Analysis ◽  
Dna Damage Response ◽  
Binding Activity ◽  
Single Stranded Dna ◽  
Dna Binding Activity ◽  
Damage Response

scholarly journals Interaction between UV-damaged DNA Binding Activity Proteins and the c-Abl Tyrosine Kinase

2002 ◽  
Vol 277 (38) ◽  
pp. 34870-34878 ◽  
Author(s):  
Feng Cong ◽  
Jean Tang ◽  
Byung Joon Hwang ◽  
Bao Q. Vuong ◽  
Gilbert Chu ◽  
...  
Keyword(s):  
Dna Binding ◽  
Tyrosine Kinase ◽  
Binding Activity ◽  
Abl Tyrosine Kinase ◽  
Dna Binding Activity ◽  
Damaged Dna

scholarly journals Protein Tyrosine Phosphatase 2 (SHP-2) Moderates Signaling by gp130 but Is Not Required for the Induction of Acute-Phase Plasma Protein Genes in Hepatic Cells

1998 ◽  
Vol 18 (3) ◽  
pp. 1525-1533 ◽  
Author(s):  
Hongkyun Kim ◽  
Teresa S. Hawley ◽  
Robert G. Hawley ◽  
Heinz Baumann
Keyword(s):  
Dna Binding ◽  
Acute Phase ◽  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Binding Activity ◽  
Wild Type ◽  
Chimeric Receptors ◽  
Dna Binding Activity ◽  
Hepatic Cells ◽  
Gp130 Receptor

ABSTRACT Signals propagated via the gp130 subunit of the interleukin-6 (IL-6)-type cytokine receptors mediate, among various cellular responses, proliferation of hematopoietic cells and induction of acute-phase plasma protein (APP) genes in hepatic cells. Hematopoietic growth control by gp130 is critically dependent on activation of both STAT3 and protein tyrosine phosphatase 2 (SHP-2). To investigate whether induction of APP genes has a similar requirement for SHP-2, we constructed two chimeric receptors, G-gp130 and G-gp130(Y2F), consisting of the transmembrane and cytoplasmic domains of gp130 harboring either a wild-type or a mutated SHP-2 binding site, respectively, fused to the extracellular domain of the granulocyte colony-stimulating factor (G-CSF) receptor. Rat hepatoma H-35 cells stably expressing the chimeric receptors were generated by retroviral transduction. Both chimeric receptors transmitted a G-CSF-induced signal characteristic of that triggered by IL-6 through the endogenous gp130 receptor; i.e., both activated the appropriate JAK, induced DNA binding activity by STAT1 and STAT3, and up-regulated expression of the target APP genes, those for α-fibrinogen and haptoglobin. Notwithstanding these similarities in the patterns of signaling responses elicited, mutation of the SHP-2 interaction site in G-gp130(Y2F) abrogated ligand-activated receptor recruitment of SHP-2 as expected. Moreover, the tyrosine phosphorylation state of the chimeric receptor, the associated JAK activity, and the induced DNA binding activity of STAT1 and STAT3 were maintained at elevated levels and for an extended period of time in G-gp130(Y2F)-expressing cells following G-CSF treatment compared to that in cells displaying the G-gp130 receptor. H-35 cells ectopically expressing G-gp130(Y2F) were also found to display an enhanced sensitivity to G-CSF and a higher level of induction of APP genes. Overexpression of the enzymatically inactive SHP-2 enhanced the signaling by the wild-type but not by the Y2F mutant G-gp130 receptor. These results indicate that gp130 signaling for APP gene induction in hepatic cells differs qualitatively from that controlling the proliferative response in hematopoietic cells in not being strictly dependent on SHP-2. The data further suggest that SHP-2 functions normally to attenuate gp130-mediated signaling in hepatic (and, perhaps, other) cells by moderating JAK action.

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