1
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Swift ML, Beishline K, Azizkhan-Clifford J. Sp1-dependent recruitment of the histone acetylase p300 to DSBs facilitates chromatin remodeling and recruitment of the NHEJ repair factor Ku70. DNA Repair (Amst) 2021; 105:103171. [PMID: 34252870 DOI: 10.1016/j.dnarep.2021.103171] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 06/18/2021] [Accepted: 07/04/2021] [Indexed: 11/18/2022]
Abstract
In response to DNA damage, most factors involved in damage recognition and repair are tightly regulated to ensure proper repair pathway choice. Histone acetylation at DNA double strand breaks (DSBs) by p300 histone acetyltransferase (HAT) is critical for the recruitment of DSB repair proteins to chromatin. Here, we show that phosphorylation of Sp1 by ATM increases its interaction with p300 and that Sp1-dependent recruitment of p300 to DSBs is necessary to modify the histones associated with p300 activity and NHEJ repair factor recruitment and repair. p300 is known to acetylate multiple residues on histones H3 and H4 necessary for NHEJ. Acetylation of H3K18 by p300 is associated with the recruitment of the SWI/SNF chromatin remodeling complex and Ku70 to DSBs for NHEJ repair. Depletion of Sp1 results in decreased acetylation of lysines on histones H3 and H4. Specifically, cells depleted of Sp1 display defects in the acetylation of H3K18, resulting in defective SWI/SNF and Ku70 recruitment to DSBs. These results shed light on mechanisms by which chromatin remodelers are regulated to ensure activation of the appropriate DSB repair pathway.
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Affiliation(s)
- Michelle L Swift
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kate Beishline
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Jane Azizkhan-Clifford
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA, USA.
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2
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Zhang Q, Hu Y, Hu JE, Ding Y, Shen Y, Xu H, Chen H, Wu N. Sp1-mediated upregulation of Prdx6 expression prevents podocyte injury in diabetic nephropathy via mitigation of oxidative stress and ferroptosis. Life Sci 2021; 278:119529. [PMID: 33894270 DOI: 10.1016/j.lfs.2021.119529] [Citation(s) in RCA: 77] [Impact Index Per Article: 25.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/12/2021] [Accepted: 04/12/2021] [Indexed: 01/19/2023]
Abstract
Glomerular podocyte damage is considered to be one of the main mechanisms leading to Diabetic nephropathy (DN). However, the relevant mechanism of podocyte injury is not yet clear. This study aimed to investigate the effect of peroxiredoxin 6 (Prdx6) on the pathogenesis of podocyte injury induced by high glucose (HG). The mouse glomerular podocyte MPC5 was stimulated with 30 nM glucose, and the Prdx6 overexpression vector or specificity protein 1 (Sp1) overexpression vector was transfected into MPC5 cells before the high glucose stimulation. As results, HG treatment significantly reduced the expression of Prdx6 and Sp1 in MPC5 cells. Prdx6 overexpression increased cell viability, while inhibited podocyte death, inflammation and podocyte destruction in HG-induced MPC5 cells. Prdx6 overexpression inhibited HG-induced ROS and MDA production, while restored SOD and GSH activity in MPC5 cells. Prdx6 overexpression also eliminated ferroptosis caused by HG, which was reflected in the suppression of iron accumulation and the increase in SLC7A11 and GPX4 expression. The improvement effect of Prdx6 on HG-induced podocyte damage could be eliminated by erastin. Moreover, Sp1 could bind to the three Sp1 response elements in the Prdx6 promoter, thereby directly regulating the transcriptional activation of Prdx6 in podocytes. Silencing Sp1 could eliminate the effect of Prdx6 on HG-induced podocyte damage. Further, Prdx6 overexpression attenuated renal injuries in streptozotocin-induced DN mice. Sp1-mediated upregulation of Prdx6 expression prevents podocyte injury in diabetic nephropathy via mitigation of oxidative stress and ferroptosis, which may provide new insights for the study of the mechanism of DN.
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Affiliation(s)
- Qianjin Zhang
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China.
| | - Yichuan Hu
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Jin-E Hu
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Ying Ding
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Yanqiu Shen
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Hong Xu
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Huiqin Chen
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
| | - Ning Wu
- Department of Endocrinology, Shuyang People's Hospital, The Affiliated Shuyang Hospital of Xuzhou Medical University, China
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3
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Wright G, Gassman NR. Transcriptional dysregulation of base excision repair proteins in breast cancer. DNA Repair (Amst) 2020; 93:102922. [PMID: 33087263 DOI: 10.1016/j.dnarep.2020.102922] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Base excision repair (BER) addresses the numerous base lesions and strand breaks induced by exogenous and endogenous stressors daily. The complexity and importance of BER requires careful regulation of basal levels of these proteins and inducible responses following DNA damage. Several reports have noted the dysregulation of BER proteins and defects in BER capacity in cancer. Modulated gene and protein expression of several BER proteins, including APE1, PARP1, POL β, and XRCC1, have been observed in breast cancer. Overexpression of these factors has been associated with chemoresistance and cancer aggressiveness, but the regulatory mechanisms that drive overexpression have not been defined. Here, we review the known transcriptional regulators of these key BER proteins and examine potential mechanisms that may drive overexpression in breast cancer.
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Affiliation(s)
- Griffin Wright
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA; Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
| | - Natalie R Gassman
- Department of Physiology and Cell Biology, University of South Alabama College of Medicine, Mobile, AL, USA; Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA
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4
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Loshchenova PS, Sergeeva SV, Fletcher SC, Dianov GL. The role of Sp1 in the detection and elimination of cells with persistent DNA strand breaks. NAR Cancer 2020; 2:zcaa004. [PMID: 34316684 PMCID: PMC8210011 DOI: 10.1093/narcan/zcaa004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 02/06/2020] [Accepted: 03/06/2020] [Indexed: 12/28/2022] Open
Abstract
Maintenance of genome stability suppresses cancer and other human diseases and is critical for organism survival. Inevitably, during a life span, multiple DNA lesions can arise due to the inherent instability of DNA molecules or due to endogenous or exogenous DNA damaging factors. To avoid malignant transformation of cells with damaged DNA, multiple mechanisms have evolved to repair DNA or to detect and eradicate cells accumulating unrepaired DNA damage. In this review, we discuss recent findings on the role of Sp1 (specificity factor 1) in the detection and elimination of cells accumulating persistent DNA strand breaks. We also discuss how this mechanism may contribute to the maintenance of physiological populations of healthy cells in an organism, thus preventing cancer formation, and the possible application of these findings in cancer therapy.
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Affiliation(s)
- Polina S Loshchenova
- Department of Natural Sciences, Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation.,Institute of Cytology and Genetics, Russian Academy of Sciences, Lavrentyeva 10, Novosibirsk 630090, Russian Federation
| | - Svetlana V Sergeeva
- Department of Natural Sciences, Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation.,Institute of Cytology and Genetics, Russian Academy of Sciences, Lavrentyeva 10, Novosibirsk 630090, Russian Federation
| | - Sally C Fletcher
- Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham B15 2TT, UK
| | - Grigory L Dianov
- Department of Natural Sciences, Novosibirsk State University, Pirogova 2, Novosibirsk 630090, Russian Federation.,Institute of Cytology and Genetics, Russian Academy of Sciences, Lavrentyeva 10, Novosibirsk 630090, Russian Federation.,Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
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5
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Antoniali G, Marcuzzi F, Casarano E, Tell G. Cadmium treatment suppresses DNA polymerase δ catalytic subunit gene expression by acting on the p53 and Sp1 regulatory axis. DNA Repair (Amst) 2015; 35:90-105. [PMID: 26519823 DOI: 10.1016/j.dnarep.2015.08.007] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/28/2015] [Accepted: 08/05/2015] [Indexed: 01/03/2023]
Abstract
Cadmium (Cd) is a carcinogenic and neurotoxic environmental pollutant. Among the proposed mechanisms for Cd toxic effects, its ability to promote oxidative stress and to inhibit, in vitro, the activities of some Base Excision DNA Repair (BER) enzymes, such as hOGG1, XRCC1 and APE1, have been already established. However, the molecular mechanisms at the basis of these processes are largely unknown especially at sub-lethal doses of Cd and no information is available on the effect of Cd on the expression levels of BER enzymes. Here, we show that non-toxic treatment of neuronal cell lines, with pro-mitogenic doses of Cd, promotes a significant time- and dose-dependent down-regulation of DNA polymerase δ (POLD1) expression through a transcriptional mechanism with a modest effect on Polβ, XRCC1 and APE1. We further elucidated that the observed transcriptional repression on Polδ is acted by through competition by activated p53 on Sp1 at POLD1 promoter and by a squelching effect. We further proved the positive effect of Sp1 not only on POLD1 expression but also on Polβ, XRCC1 and APE1 expression, suggesting that Sp1 has pleiotropic effects on the whole BER pathway. Our results indicated that Cd-mediated impairment of BER pathway, besides acting on the enzymatic functions of some key proteins, is also exerted at the gene expression level of Polδ by acting on the p53-Sp1 regulatory axis. These data may explain not only the Cd-induced neurotoxic effects but also the potential carcinogenicity of this heavy metal.
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Affiliation(s)
- Giulia Antoniali
- Laboratory of Molecular Biology and DNA Repair, Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
| | - Federica Marcuzzi
- Laboratory of Molecular Biology and DNA Repair, Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
| | - Elena Casarano
- Laboratory of Molecular Biology and DNA Repair, Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy
| | - Gianluca Tell
- Laboratory of Molecular Biology and DNA Repair, Department of Medical and Biological Sciences, University of Udine, 33100 Udine, Italy.
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6
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Unnikrishnan A, Prychitko TM, Patel HV, Chowdhury ME, Pilling AB, Ventrella-Lucente LF, Papakonstantinou EV, Cabelof DC, Heydari AR. Folate deficiency regulates expression of DNA polymerase β in response to oxidative stress. Free Radic Biol Med 2011; 50:270-80. [PMID: 21070850 PMCID: PMC3018545 DOI: 10.1016/j.freeradbiomed.2010.11.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 10/08/2010] [Accepted: 11/01/2010] [Indexed: 01/19/2023]
Abstract
Folate deficiency has been shown to influence carcinogenesis by creating an imbalance in the base excision repair (BER) pathway, affecting BER homeostasis. The inability to mount a BER response to oxidative stress in a folate-deficient environment results in the accumulation of DNA repair intermediates, i.e., DNA strand breaks. Our data indicate that upregulation of β-pol expression in response to oxidative stress is inhibited by folate deficiency at the level of gene expression. Alteration in the expression of β-pol in a folate-deficient environment is not due to epigenetic changes in the core promoter of the β-pol gene, i.e., the CpG islands within the β-pol promoter remain unmethylated in the presence or absence of folate. However, the promoter analysis studies show a differential binding of regulatory factors to the -36 to -7 region (the folic acid-response region, FARR) within the core promoter of β-pol. Moreover, we observe a tight correlation between the level of binding of regulatory factors with the FARR and inhibition of β-pol expression. Based on these findings, we propose that folate deficiency results in an upregulation/stability of negative regulatory factors interacting with FARR, repressing the upregulation of the β-pol gene in response to oxidative stress.
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Affiliation(s)
- Archana Unnikrishnan
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Tom M. Prychitko
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Hiral V. Patel
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Mahbuba E. Chowdhury
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Amanda B. Pilling
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Lisa F. Ventrella-Lucente
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Erin V. Papakonstantinou
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
| | - Diane C. Cabelof
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
- Barbara Ann Karmanos Cancer Institute, School of Medicine, Wayne State University, Detroit, Michigan 48202
| | - Ahmad R. Heydari
- Department of Nutrition and Food science, Science College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan 48202
- Barbara Ann Karmanos Cancer Institute, School of Medicine, Wayne State University, Detroit, Michigan 48202
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7
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Faumont N, Le Clorennec C, Teira P, Goormachtigh G, Coll J, Canitrot Y, Cazaux C, Hoffmann JS, Brousset P, Delsol G, Feuillard J, Meggetto F. Regulation of DNA polymerase beta by the LMP1 oncoprotein of EBV through the nuclear factor-kappaB pathway. Cancer Res 2009; 69:5177-85. [PMID: 19491276 DOI: 10.1158/0008-5472.can-08-2866] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The repair DNA polymerase beta (Polbeta), when overexpressed, plays a critical role in generating genetic instability via its interference with the genomic replication program. Up-regulation of Polbeta has been reported in many tumor types that exhibit genetic aberrations, including EBV-related B-cell lymphomas. However, the mechanisms responsible for its overexpression have never been examined. Here, we report that both expression and activity of Polbeta, in EBV-immortalized B cells, are induced by several natural genetic variants of LMP1, an oncoprotein associated with the vast majority of EBV-related tumors. Conversely, we found that the expression of Polbeta decreased when LMP1 signaling was down-regulated by a dominant negative of LMP1 or an inhibitor of the nuclear factor-kappaB (NF-kappaB) pathway, the main transduction pathway activated by LMP1, strongly supporting a role of NF-kappaB in the LMP1-mediated Polbeta regulation. Using electrophoretic mobility shift assay experiments from several EBV-immortalized B-cell nuclear extracts, we identified an LMP1-dependent p50/c-Rel heterodimer on a proximal kappaB binding site (-211 to -199nt) of the Polbeta promoter. This result was correlated with a specific Polbeta kappaB transcriptional activity. Taken together, our data enlighten a new mechanism responsible for Polbeta overexpression in EBV-infected cells, mediated by LMP1 and dependent on NF-kappaB activation.
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Affiliation(s)
- Nathalie Faumont
- Institut National de la Sante et de la Recherche Medicale-U563, CPTP
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8
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Sarnowska E, Grzybowska EA, Sobczak K, Konopiński R, Wilczyńska A, Szwarc M, Sarnowski TJ, Krzyżosiak WJ, Siedlecki JA. Hairpin structure within the 3'UTR of DNA polymerase beta mRNA acts as a post-transcriptional regulatory element and interacts with Hax-1. Nucleic Acids Res 2007; 35:5499-510. [PMID: 17704138 PMCID: PMC2018635 DOI: 10.1093/nar/gkm502] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Aberrant expression of DNA polymerase beta, a key enzyme involved in base excision repair, leads to genetic instability and carcinogenesis. Pol beta expression has been previously shown to be regulated at the level of transcription, but there is also evidence of post-transcriptional regulation, since rat transcripts undergo alternative polyadenylation, and the resulting 3'UTR contain at least one regulatory element. Data presented here indicate that RNA of the short 3'UTR folds to form a strong secondary structure (hairpin). Its regulatory role was established utilizing a luciferase-based reporter system. Further studies led to the identification of a protein factor, which binds to this element-the anti-apoptotic, cytoskeleton-related protein Hax-1. The results of in vitro binding analysis indicate that the formation of the RNA-protein complex is significantly impaired by disruption of the hairpin motif. We demonstrate that Hax-1 binds to Pol beta mRNA exclusively in the form of a dimer. Biochemical analysis revealed the presence of Hax-1 in mitochondria, but also in the nuclear matrix, which, along with its transcript-binding properties, suggests that Hax-1 plays a role in post-transcriptional regulation of expression of Pol beta.
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Affiliation(s)
- Elżbieta Sarnowska
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Ewa A. Grzybowska
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
- *To whom correspondence should be addressed. +48 22 546 23 68+48 22 644 02 09
| | - Krzysztof Sobczak
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Ryszard Konopiński
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Anna Wilczyńska
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Maria Szwarc
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Tomasz J. Sarnowski
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Włodzimierz J. Krzyżosiak
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
| | - Janusz A. Siedlecki
- Cancer Center Institute, Roentgena 5, 02-781 Warsaw, Institute of Bioorganic Chemistry, PAS, Noskowskiego 12/14, 61-704, Poznań and Institute of Biochemistry and Biophysics, PAS, Pawińskiego 5A, 02-106, Warsaw, Poland
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9
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Zhao Y, Zheng J, Ling Y, Hou L, Zhang B. Transcriptional upregulation of DNA polymerase beta by TEIF. Biochem Biophys Res Commun 2005; 333:908-16. [PMID: 15963946 DOI: 10.1016/j.bbrc.2005.05.172] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 05/24/2005] [Indexed: 11/19/2022]
Abstract
The overexpression of DNA polymerase beta (beta-pol) has been identified in lots of human cancers, but the mechanism has seldom been investigated. Telomerase transcriptional element-interacting factor (TEIF) can bind to hTERT promoter, stimulating its transcription and telomerase activities. Here, we report that TEIF could also enhance the expression of beta-pol at transcription level. TEIF could specifically activate transcription of beta-pol promoter, but not that of DNA polymerase alpha or delta promoter. The responsible sequences for binding of TEIF were revealed as GC-rich elements dispersing from +19 to -29 nt of beta-pol promoter, which due to mutations caused decreasing in binding of TEIF and apparent losing of transactivation activity. The in vivo interaction between TEIF and beta-pol promoter was identified by chromatin immunoprecipitation assay. Besides, ectopic expression of TEIF in HeLa cells could upregulate both levels of endogenous beta-pol mRNA and protein, and consequently increases resistance to the oxidative stress of H2O2. The data may provide new clue to the elucidation of beta-pol overexpression in cancers and also a functional link between beta-pol and telomerase.
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Affiliation(s)
- Yuanjun Zhao
- Department of Pathology, Health Science Center, Peking University, Beijing 100083, China
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10
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Tomitori H, Nenoi M, Mita K, Daino K, Igarashi K, Ichimura S. Functional characterization of the human spermidine/spermine N(1)-acetyltransferase gene promoter. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1579:180-4. [PMID: 12427553 DOI: 10.1016/s0167-4781(02)00545-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Spermidine/spermine N(1)-acetyltransferase (SSAT), the key enzyme of polyamine catabolism, is induced by antiproliferative stresses. We analyzed the 5' flanking region of the human SSAT gene, and clarified that the binding of Sp1 to the GC-box located 42 to 51 bp upstream from the transcription start site is essential for transcription in HeLa S3 cells. A polyamine-responsive element (PRE) seemed to be responsible for the elevated transcription after X-ray irradiation.
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Affiliation(s)
- Hideyuki Tomitori
- Department of Clinical Biochemistry, Graduate School of Pharmaceutical Sciences, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, Japan
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11
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Catz SD, Babior BM, Johnson JL. JFC1 is transcriptionally activated by nuclear factor-kappaB and up-regulated by tumour necrosis factor alpha in prostate carcinoma cells. Biochem J 2002; 367:791-9. [PMID: 12137562 PMCID: PMC1222920 DOI: 10.1042/bj20020345] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2002] [Revised: 07/09/2002] [Accepted: 07/23/2002] [Indexed: 11/17/2022]
Abstract
The human promoter region of JFC1, a phosphatidylinositol 3,4,5-trisphosphate binding ATPase, was isolated by amplification of a 549 bp region upstream of the jfc1 gene by the use of a double-PCR system. By primer extension analysis we mapped the transcription initiation site at nucleotide -321 relative to the translation start site. Putative regulatory elements were identified in the jfc1 TATA-less promoter, including three consensus sites for nuclear factor-kappaB (NF-kappaB). We analysed the three putative NF-kappaB binding sites by gel retardation and supershift assays. Each of the putative NF-kappaB sites interacted specifically with recombinant NF-kappaB p50, and the complexes co-migrated with those formed by the NF-kappaB consensus sequence and p50. An antibody to p50 generated a supershifted complex for these NF-kappaB sites. These sites formed specific complexes with nuclear proteins from tumour necrosis factor alpha (TNFalpha)-treated WEHI 231 cells, which were supershifted with antibodies against p50 and p65. The jfc1 promoter was transcriptionally active in various cell lines, as determined by luciferase reporter assays following transfection with a jfc1 promoter luciferase vector. Co-transfection with NF-kappaB expression vectors or stimulation with TNFalpha resulted in significant transactivation of the jfc1 promoter construct, although transactivation of a mutated jfc1 promoter was negligible. The expression of a dominant negative IkappaB (inhibitor kappaB) decreased basal jfc1 promoter activity. The cell lines PC-3, LNCaP and DU-145, but not Epstein-Barr virus-transformed lymphocytes, showed a dramatic increase in the expression of JFC1 after treatment with TNFalpha, suggesting that transcriptional activation of JFC1 by the TNFalpha/NF-kappaB pathway is significant in prostate carcinoma cell lines.
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Affiliation(s)
- Sergio D Catz
- Biochemistry Division, Department of Molecular and Experimental Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
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12
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Srivastava DK, Tendler CL, Milani D, English MA, Licht JD, Wilson SH. The HIV-1 transactivator protein Tat is a potent inducer of the human DNA repair enzyme beta-polymerase. AIDS 2001; 15:433-40. [PMID: 11242139 DOI: 10.1097/00002030-200103090-00001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE This study examines the effects of the HIV-1 regulatory proteins, Tat and Rev, on the expression of the DNA polymerase beta (beta-pol) gene, which encodes a key protein in the DNA base-excision repair pathway. The rationale for these experiments is to examine the potential involvement of base-excision repair protein deregulation in HIV-1-related lymphomas. DESIGN Expression of beta-pol mRNA was examined in AIDS-related lymphomas and non-AIDS-related lymphomas and as a function of HIV-1 infection of B cells in culture. The effect of Tat or Rev over-expression on beta-pol promoter expression was tested by transient co-transfection assays with a beta-pol promoter reporter plasmid and a Tat or Rev over-expression plasmid. METHODS Northern blot analysis was used to quantitate beta-pol expression in lymphoma and cells. Raji cells were co-transfected with a chloramphenicol acetyltransferase (CAT) reporter plasmid and a plasmid over-expressing Tat or Rev. CAT activity was measured in transfected cells. RESULTS beta-Pol mRNA was > 10-fold higher in AIDS-related than in non-AIDS B-lineage lymphomas. beta-Pol expression was up-regulated in a B-cell line upon infection with HIV-1, and increased in Raji cells upon recombinant expression of the Tat gene. The beta-pol promoter was transactivated (fourfold induction) by Tat, but not by Rev. Tat-dependent transactivation required a binding site for the transcription factor Sp1 in the beta-pol promoter. CONCLUSION These results suggest that HIV-1 Tat can interact with cellular transcription factors to increase the steady-state level of beta-pol in B cells. Tat-mediated induction of beta-pol may alter DNA stability in AIDS-related lymphomas.
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MESH Headings
- Animals
- Base Sequence
- Chloramphenicol O-Acetyltransferase/genetics
- DNA Polymerase beta/biosynthesis
- DNA Polymerase beta/genetics
- Enzyme Induction
- Gene Expression Regulation, Viral
- Gene Products, rev/pharmacology
- Gene Products, tat/pharmacology
- HIV-1/genetics
- Humans
- Lymphoma, AIDS-Related/genetics
- Lymphoma, AIDS-Related/metabolism
- Lymphoma, B-Cell/genetics
- Molecular Sequence Data
- Plasmids
- Promoter Regions, Genetic
- RNA, Messenger/metabolism
- Transcription, Genetic
- Transfection
- Tumor Cells, Cultured
- Up-Regulation
- rev Gene Products, Human Immunodeficiency Virus
- tat Gene Products, Human Immunodeficiency Virus
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Affiliation(s)
- D K Srivastava
- Laboratory of Structural Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, USA
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