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Li X, Khan D, Rana M, Hänggi D, Muhammad S. Doxycycline Attenuated Ethanol-Induced Inflammaging in Endothelial Cells: Implications in Alcohol-Mediated Vascular Diseases. Antioxidants (Basel) 2022; 11:antiox11122413. [PMID: 36552622 PMCID: PMC9774758 DOI: 10.3390/antiox11122413] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/05/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
Excess alcohol consumption is a potential risk factor for cardiovascular diseases and is linked to accelerated aging. Drug discovery to reduce toxic cellular events of alcohol is required. Here, we investigated the effects of ethanol on human umbilical vein endothelial cells (HUVECs) and explored if doxycycline attenuates ethanol-mediated molecular events in endothelial cells. Initially, a drug screening using a panel of 170 drugs was performed, and doxycycline was selected for further experiments. HUVECs were treated with different concentrations (300 mM and 400 mM) of ethanol with or without doxycycline (10 µg/mL). Telomere length was quantified as telomere to single-copy gene (T/S) ratio. Telomere length and the mRNA expression were quantified by qRT-PCR, and protein level was analyzed by Western blot (WB). Ethanol treatment accelerated cellular aging, and doxycycline treatment recovered telomere length. Pathway analysis showed that doxycycline inhibited mTOR and NFκ-B activation. Doxycycline restored the expression of aging-associated proteins, including lamin b1 and DNA repair proteins KU70 and KU80. Doxycycline reduced senescence and senescence-associated secretory phenotype (SASP) in ethanol-treated HUVECs. In conclusion, we report that ethanol-induced inflammation and aging in HUVECs were ameliorated by doxycycline.
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Affiliation(s)
- Xuanchen Li
- Department of Neurosurgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Dilaware Khan
- Department of Neurosurgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
- Correspondence: ; Tel.: +49-21181-08782
| | - Majeed Rana
- Department of Oral and Maxillofacial Surgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Daniel Hänggi
- Department of Neurosurgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Sajjad Muhammad
- Department of Neurosurgery, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
- Department of Neurosurgery, University Hospital Helsinki, Topeliuksenkatu 5, 00260 Helsinki, Finland
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Abbasi S, Parmar G, Kelly RD, Balasuriya N, Schild-Poulter C. The Ku complex: recent advances and emerging roles outside of non-homologous end-joining. Cell Mol Life Sci 2021; 78:4589-4613. [PMID: 33855626 PMCID: PMC11071882 DOI: 10.1007/s00018-021-03801-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 01/29/2021] [Accepted: 02/24/2021] [Indexed: 12/15/2022]
Abstract
Since its discovery in 1981, the Ku complex has been extensively studied under multiple cellular contexts, with most work focusing on Ku in terms of its essential role in non-homologous end-joining (NHEJ). In this process, Ku is well-known as the DNA-binding subunit for DNA-PK, which is central to the NHEJ repair process. However, in addition to the extensive study of Ku's role in DNA repair, Ku has also been implicated in various other cellular processes including transcription, the DNA damage response, DNA replication, telomere maintenance, and has since been studied in multiple contexts, growing into a multidisciplinary point of research across various fields. Some advances have been driven by clarification of Ku's structure, including the original Ku crystal structure and the more recent Ku-DNA-PKcs crystallography, cryogenic electron microscopy (cryoEM) studies, and the identification of various post-translational modifications. Here, we focus on the advances made in understanding the Ku heterodimer outside of non-homologous end-joining, and across a variety of model organisms. We explore unique structural and functional aspects, detail Ku expression, conservation, and essentiality in different species, discuss the evidence for its involvement in a diverse range of cellular functions, highlight Ku protein interactions and recent work concerning Ku-binding motifs, and finally, we summarize the clinical Ku-related research to date.
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Affiliation(s)
- Sanna Abbasi
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Gursimran Parmar
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Rachel D Kelly
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Nileeka Balasuriya
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada
| | - Caroline Schild-Poulter
- Robarts Research Institute and Department of Biochemistry, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, N6A 5B7, Canada.
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3
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Fan Y, Li J, Wei W, Fang H, Duan Y, Li N, Zhang Y, Yu J, Wang J. Ku80 gene knockdown by the CRISPR/Cas9 technique affects the biological functions of human thyroid carcinoma cells. Oncol Rep 2019; 42:2486-2498. [PMID: 31578590 PMCID: PMC6826323 DOI: 10.3892/or.2019.7348] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 08/19/2019] [Indexed: 12/23/2022] Open
Abstract
In the present study, to evaluate the role of Ku80 in thyroid carcinoma (TC), 86 thyroid tissue samples from patients with a spectrum of thyroid disorders were examined for protein levels of Ku80, nuclear factor-κB (NF-κB) and RET/TC by immunohistochemistry. Furthermore, in TC cells, Ku80 mRNA was detected by reverse transcription-quantitative PCR analysis and silenced using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technique to assess its role. An antibody array was used to identify Ku80-related regulatory genes. The protein levels of Ku80 in the TC tissues were significantly higher than those in non-neoplastic adjacent tissue samples (P<0.01). The activation of NF-kB and expression of RET/TC in the TC group were significantly increased (P<0.05) and were correlated with the protein expression of Ku80 (P<0.05). In papillary TC cells, the mRNA levels of Ku80 were high; Ku80 knockdown resulted in reductions in proliferation, invasion and colony formation, increased apoptosis, and reduced levels of proteins involved in MAPK signaling, cell proliferation and apoptosis. The high expression of Ku80 in TC was found to be associated with the expression of RET/TC and activation of NF-κB, and Ku80 knockdown decreased the malignancy of TC cells.
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Affiliation(s)
- Yali Fan
- Department of Respiratory Medicine, Xi'an Central Hospital, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710003, P.R. China
| | - Jianying Li
- Department of Respiratory Medicine, Xi'an Central Hospital, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710003, P.R. China
| | - Wei Wei
- Department of Pathology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710018, P.R. China
| | - Hangrong Fang
- Department of Pathology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710018, P.R. China
| | - Ying Duan
- Department of Pathology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710018, P.R. China
| | - Namiao Li
- Department of Respiratory Medicine, Xi'an Central Hospital, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710003, P.R. China
| | - Yingying Zhang
- Department of Respiratory Medicine, Xi'an Central Hospital, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710003, P.R. China
| | - Jun Yu
- Department of Emergency, Xi'an Central Hospital, The Affiliated Hospital of Xi'an Jiaotong University, Xi'an, Shaanxi 710003, P.R. China
| | - Juanhong Wang
- Department of Pathology, Xi'an No. 3 Hospital, The Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710018, P.R. China
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Manic G, Maurin-Marlin A, Laurent F, Vitale I, Thierry S, Delelis O, Dessen P, Vincendeau M, Leib-Mösch C, Hazan U, Mouscadet JF, Bury-Moné S. Impact of the Ku complex on HIV-1 expression and latency. PLoS One 2013; 8:e69691. [PMID: 23922776 PMCID: PMC3726783 DOI: 10.1371/journal.pone.0069691] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 06/17/2013] [Indexed: 01/20/2023] Open
Abstract
Ku, a cellular complex required for human cell survival and involved in double strand break DNA repair and multiple other cellular processes, may modulate retroviral multiplication, although the precise mechanism through which it acts is still controversial. Recently, Ku was identified as a possible anti-human immunodeficiency virus type 1 (HIV-1) target in human cells, in two global approaches. Here we investigated the role of Ku on the HIV-1 replication cycle by analyzing the expression level of a panel of non-replicative lentiviral vectors expressing the green fluorescent protein in human colorectal carcinoma HCT 116 cells, stably or transiently depleted of Ku. We found that in this cellular model the depletion of Ku did not affect the efficiency of (pre-)integrative steps but decreased the early HIV-1 expression by acting at the transcriptional level. This negative effect was specific of the HIV-1 promoter, required the obligatory step of viral DNA integration and was reversed by transient depletion of p53. We also provided evidence on a direct binding of Ku to HIV-1 LTR in transduced cells. Ku not only promotes the early transcription from the HIV-1 promoter, but also limits the constitution of viral latency. Moreover, in the presence of a normal level of Ku, HIV-1 expression was gradually lost over time, likely due to the counter-selection of HIV-1-expressing cells. On the contrary, the reactivation of transgene expression from HIV-1 by means of trichostatin A- or tumor necrosis factor α-administration was enhanced under condition of Ku haplodepletion, suggesting a phenomenon of provirus latency. These observations plead in favor of the hypothesis that Ku has an impact on HIV-1 expression and latency at early- and mid-time after integration.
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Affiliation(s)
- Gwenola Manic
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Aurélie Maurin-Marlin
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Fanny Laurent
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Ilio Vitale
- Regina Elena National Cancer Institute, Rome, Italy
- National Institute of Health, Rome, Italy
| | - Sylvain Thierry
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Olivier Delelis
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Philippe Dessen
- Institut Gustave Roussy, Villejuif, France
- Institut National de la Santé et de la Recherche Médicale-U985, Villejuif, France
| | - Michelle Vincendeau
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Research Unit Cellular Signal Integration, Institute of Molecular Toxicology and Pharmacology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Christine Leib-Mösch
- Institute of Virology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
- Department of Hematology and Oncology, Mannheim Medical Center, University of Heidelberg, Mannheim, Germany
| | - Uriel Hazan
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Jean-François Mouscadet
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
| | - Stéphanie Bury-Moné
- Laboratoire de Biologie et Pharmacologie Appliquée, Centre national de la recherche scientifique-UMR8113, Ecole Normale Supérieure de Cachan, Cachan, France
- * E-mail:
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Nishizawa-Yokoi A, Nonaka S, Saika H, Kwon YI, Osakabe K, Toki S. Suppression of Ku70/80 or Lig4 leads to decreased stable transformation and enhanced homologous recombination in rice. THE NEW PHYTOLOGIST 2012; 196:1048-1059. [PMID: 23050791 PMCID: PMC3532656 DOI: 10.1111/j.1469-8137.2012.04350.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 08/23/2012] [Indexed: 05/13/2023]
Abstract
Evidence for the involvement of the nonhomologous end joining (NHEJ) pathway in Agrobacterium-mediated transferred DNA (T-DNA) integration into the genome of the model plant Arabidopsis remains inconclusive. Having established a rapid and highly efficient Agrobacterium-mediated transformation system in rice (Oryza sativa) using scutellum-derived calli, we examined here the involvement of the NHEJ pathway in Agrobacterium-mediated stable transformation in rice. Rice calli from OsKu70, OsKu80 and OsLig4 knockdown (KD) plants were infected with Agrobacterium harboring a sensitive emerald luciferase (LUC) reporter construct to evaluate stable expression and a green fluorescent protein (GFP) construct to monitor transient expression of T-DNA. Transient expression was not suppressed, but stable expression was reduced significantly, in KD plants. Furthermore, KD-Ku70 and KD-Lig4 calli exhibited an increase in the frequency of homologous recombination (HR) compared with control calli. In addition, suppression of OsKu70, OsKu80 and OsLig4 induced the expression of HR-related genes on treatment with DNA-damaging agents. Our findings suggest strongly that NHEJ is involved in Agrobacterium-mediated stable transformation in rice, and that there is a competitive and complementary relationship between the NHEJ and HR pathways for DNA double-strand break repair in rice.
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Affiliation(s)
- Ayako Nishizawa-Yokoi
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Satoko Nonaka
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
- Graduate School of Life and Environmental Sciences, University of Tsukuba1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Hiroaki Saika
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Yong-Ik Kwon
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
- Kihara Institute for Biological Research, Yokohama City University641-12 Maioka-cho, Yokohama 244-0813, Japan
| | - Keishi Osakabe
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
- Institute for Environmental Science and Technology, Saitama UniversityShimo-Okubo 255, Sakura-ku, Saitama-shi, 338-8570 Japan
| | - Seiichi Toki
- Plant Genome Engineering Research Unit, National Institute of Agrobiological Sciences2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
- Kihara Institute for Biological Research, Yokohama City University641-12 Maioka-cho, Yokohama 244-0813, Japan
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6
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Clone F10H2.B3 Anti-Ku80. Hybridoma (Larchmt) 2009. [DOI: 10.1089/hyb.2008.0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Mikelsaar AV, Sünter A, Toomik P, Karpson K, Juronen E. New anti-Ku80 monoclonal antibody F10H2.B3 as a useful marker for dividing cells in culture. Hybridoma (Larchmt) 2009; 28:107-11. [PMID: 19249991 DOI: 10.1089/hyb.2008.0077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report on the development of a mouse monoclonal antibody (named F10H2.B3) using the native cellular fragments of human fetal neural stem cells as immunogens. Molecular analysis has shown that the target antigen of F10H2.B3 is Ku80 (ATP-dependent DNA helicase 2 subunit 2 [EC 3.6.1.-]). We suggest this antibody could be used in certain conditions as a proliferation marker for cells of different origin.
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8
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Liu K, Qian L, Wang J, Li W, Deng X, Chen X, Sun W, Wei H, Qian X, Jiang Y, He F. Two-dimensional blue native/SDS-PAGE analysis reveals heat shock protein chaperone machinery involved in hepatitis B virus production in HepG2.2.15 cells. Mol Cell Proteomics 2008; 8:495-505. [PMID: 18984579 DOI: 10.1074/mcp.m800250-mcp200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Hepatitis B virus (HBV) infection is a major health concern with more than two billion individuals currently infected worldwide. Despite the prevalence of infection, gaining a complete understanding of the molecular mechanisms of HBV infection has been difficult because HBV cannot infect common immortalized cell lines. HepG2.2.15, however, is a well established version of the HepG2 cell line that constitutively expresses HBV. Therefore, comparative proteomics analysis of HepG2.2.15 and HepG2 may provide valuable clues for understanding the HBV virus life cycle. In this study, two-dimensional blue native/SDS-PAGE was utilized to characterize different multiprotein complexes from whole cell lysates between HepG2.2.15 and HepG2. These results demonstrate that two unique protein complexes existed in HepG2.2.15 cells. When these complexes were excised from the gel and subjected to the second dimension separation and the proteins were sequenced by mass spectrometry, 20 non-redundant proteins were identified. Of these proteins, almost 20% corresponded to heat shock proteins, including HSP60, HSP70, and HSP90. Antibody-based supershift assays were used to verify the validity of the distinct protein complexes. Co-immunoprecipitation assays confirmed that HSP60, HSP70, and HSP90 proteins physically interacted in HepG2.2.15 but not HepG2 cells. We further demonstrated that down-regulation of HSP70 or HSP90 by small interfering RNA significantly inhibited HBV viral production but did not influence cellular proliferation or apoptosis. Consistent with these results, a significant reduction in HepG2.2.15 HBV secretion was observed when the HSP90 inhibitor 17-allylamino-17-demethoxygeldanamycin was used to treat HepG2.2.15 cells. Collectively these results suggest that the interaction of HSP90 with HSP70/HSP60 contributes to the HBV life cycle by forming a multichaperone machine that may constitute therapeutic targets for HBV-associated diseases.
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Affiliation(s)
- Kun Liu
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 102206, China
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9
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Bednarek R, Boncela J, Smolarczyk K, Cierniewska-Cieslak A, Wyroba E, Cierniewski CS. Ku80 as a Novel Receptor for Thymosin β4 That Mediates Its Intracellular Activity Different from G-actin Sequestering. J Biol Chem 2008; 283:1534-1544. [DOI: 10.1074/jbc.m707539200] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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Yin H, Glass J. In prostate cancer cells the interaction of C/EBPalpha with Ku70, Ku80, and poly(ADP-ribose) polymerase-1 increases sensitivity to DNA damage. J Biol Chem 2006; 281:11496-505. [PMID: 16490787 DOI: 10.1074/jbc.m511138200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Prostate cancer cell lines were examined for proteins that partnered with the transcription factor C/EBPalpha by use of a pull-down assay with S-tagged C/EBPalpha combined with matrix-assisted laser desorption ionization time-of-flight mass spectroscopy analysis. Ku70, Ku80, and poly(ADP-ribose) polymerase-1 (PARP-1) were identified as proteins that associated with C/EBPalpha. The physical interaction of C/EBPalpha with these partner proteins was further demonstrated by glutathione S-transferase (GST) pull-downs using purified protein expressed in Escherichia coli. The strongest binding was between C/EBPalpha and PARP-1. Immunoprecipitation of C/EBPalpha expressed in prostate cancer cells co-precipitated Ku70, Ku80, and PARP-1. Deletion analysis of C/EBPalpha indicated that the C terminus of C/EBPalpha was essential for the interaction of C/EBPalpha with Ku70, Ku80, and PARP-1. Functional analysis of the interaction between C/EBPalpha and the Ku proteins as well as PARP-1 showed that cells exhibiting these interactions had increased radiation sensitivity and decreased ability to repair double strand DNA breaks. Deficient DNA repair was dependent on the prostate cancer cell line tested, suggesting a complex process. We conclude that the association of C/EBPalpha with Ku proteins and PARP-1 raises the likelihood that C/EBPalpha-expressing prostate cancer cells may be more sensitive to DNA-damaging agents and may be important in the design of new prostate cancer therapies.
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Affiliation(s)
- Hong Yin
- Feist-Weiller Cancer Center and Department of Medicine, Health Sciences Center, Shreveport, Louisiana 71130-3932, USA.
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11
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Mayeur GL, Kung WJ, Martinez A, Izumiya C, Chen DJ, Kung HJ. Ku is a novel transcriptional recycling coactivator of the androgen receptor in prostate cancer cells. J Biol Chem 2005; 280:10827-33. [PMID: 15640154 DOI: 10.1074/jbc.m413336200] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The androgen receptor (AR) dynamically assembles and disassembles multicomponent receptor complexes in order to respond rapidly and reversibly to fluctuations in androgen levels. We are interested in identifying the basal factors that compose the AR aporeceptor and holoreceptor complexes and impact the transcriptional process. Using tandem mass spectroscopy analysis, we identified the trimeric DNA-dependent protein kinase (DNA-PK) complex as the major AR-interacting proteins. AR directly interacts with both Ku70 and Ku80 in vivo and in vitro, as shown by co-immunoprecipitation, glutathione S-transferase pull-down, and Sf9 cell/baculovirus expression. The interaction was localized to the androgen receptor ligand binding domain and is independent of DNA interactions. Ku interacts with AR in the cytoplasm and nucleus regardless of the presence or absence of androgen. Ku acts as a coactivator of AR activity in a luciferase reporter assay employing both Ku-defective cells and Ku small interfering RNA knock-down in a prostate cancer cell line. DNA-PK catalytic subunit (DNA-PKcs) also acts as a coactivator of androgen receptor activity in a luciferase reporter assay employing DNA-PKcs defective cells. AR nuclear translocation is not affected in Ku defective cells, implying Ku functionality may be mainly nuclear. Chromatin immunoprecipitation experiments demonstrated that both Ku70 and Ku80 interact with the prostate-specific antigen promoter in an androgen-dependant manner. Finally, in vitro transcription assays demonstrated Ku involvement in transcriptional recycling with androgen dependent promoters.
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MESH Headings
- Androgens/metabolism
- Animals
- Antigens, Nuclear/chemistry
- Antigens, Nuclear/metabolism
- Antigens, Nuclear/physiology
- Cell Line
- Cell Line, Tumor
- Cell Nucleus/metabolism
- Chromatin/metabolism
- Chromatin Immunoprecipitation
- Cytoplasm/metabolism
- DNA/chemistry
- DNA-Binding Proteins/chemistry
- DNA-Binding Proteins/metabolism
- DNA-Binding Proteins/physiology
- Electrophoresis, Polyacrylamide Gel
- Genes, Reporter
- Glutathione Transferase/metabolism
- Humans
- Immunoprecipitation
- Insecta
- Ku Autoantigen
- Ligands
- Luciferases/metabolism
- Male
- Mass Spectrometry
- Models, Genetic
- Prostatic Neoplasms/metabolism
- Protein Binding
- Protein Structure, Tertiary
- RNA/metabolism
- RNA, Small Interfering/metabolism
- Receptors, Androgen/metabolism
- Signal Transduction
- Transcription, Genetic
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Affiliation(s)
- Greg L Mayeur
- Department of Biological Chemistry, School of Medicine, University of California, Davis, UC Davis Cancer Center, Sacramento, California 95817, USA
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12
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Sucharov CC, Helmke SM, Langer SJ, Perryman MB, Bristow M, Leinwand L. The Ku protein complex interacts with YY1, is up-regulated in human heart failure, and represses alpha myosin heavy-chain gene expression. Mol Cell Biol 2004; 24:8705-15. [PMID: 15367688 PMCID: PMC516749 DOI: 10.1128/mcb.24.19.8705-8715.2004] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human heart failure is accompanied by repression of genes such as alpha myosin heavy chain (alphaMyHC) and SERCA2A and the induction of fetal genes such as betaMyHC and atrial natriuretic factor. It seems likely that changes in MyHC isoforms contribute to the poor contractility seen in heart failure, because small changes in isoform composition can have a major effect on the contractility of cardiac myocytes and the heart. Our laboratory has recently shown that YY1 protein levels are increased in human heart failure and that YY1 represses the activity of the human alphaMyHC promoter. We have now identified a region of the alphaMyHC promoter that binds a factor whose expression is increased sixfold in failing human hearts. Through peptide mass spectrometry, we identified this binding activity to be a heterodimer of Ku70 and Ku80. Expression of Ku represses the human alphaMyHC promoter in neonatal rat ventricular myocytes. Moreover, overexpression of Ku70/80 decreases alphaMyHC mRNA expression and increases skeletal alpha-actin. Interestingly, YY1 interacts with Ku70 and Ku80 in HeLa cells. Together, YY1, Ku70, and Ku80 repress the alphaMyHC promoter to an extent that is greater than that with YY1 or Ku70/80 alone. Our results suggest that Ku is an important factor in the repression of the human alphaMyHC promoter during heart failure.
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Affiliation(s)
- Carmen C Sucharov
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, USA
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Abstract
Cells induce the expression of DNA-repair enzymes, activate cell-cycle checkpoints and, under some circumstances, undergo apoptosis in response to DNA-damaging agents. The mechanisms by which these cellular responses are triggered are not well understood, but there is recent evidence that the transcription machinery might be used in DNA-damage surveillance and in triggering DNA-damage responses to suppress mutagenesis. Transcription might also act as a DNA-damage dosimeter where the severity of blockage determines whether or not to induce cell death. Could transcription therefore be a potential therapeutic target for anticancer strategies?
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Affiliation(s)
- Mats Ljungman
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, University of Michigan Comprehensive Cancer Center, University of Michigan Medical School, University of Michigan, Ann Arbor, Michigan 48109-0936, USA.
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Zhang S, Schlott B, Görlach M, Grosse F. DNA-dependent protein kinase (DNA-PK) phosphorylates nuclear DNA helicase II/RNA helicase A and hnRNP proteins in an RNA-dependent manner. Nucleic Acids Res 2004; 32:1-10. [PMID: 14704337 PMCID: PMC373260 DOI: 10.1093/nar/gkg933] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
An RNA-dependent association of Ku antigen with nuclear DNA helicase II (NDH II), alternatively named RNA helicase A (RHA), was found in nuclear extracts of HeLa cells by immunoprecipitation and by gel filtration chromatography. Both Ku antigen and NDH II were associated with hnRNP complexes. Two-dimensional gel electrophoresis showed that Ku antigen was most abundantly associated with hnRNP C, K, J, H and F, but apparently not with others, such as hnRNP A1. Unexpectedly, DNA-dependent protein kinase (DNA-PK), which comprises Ku antigen as the DNA binding subunit, phosphorylated hnRNP proteins in an RNA-dependent manner. DNA-PK also phosphorylated recombinant NDH II in the presence of RNA. RNA binding assays displayed a preference of DNA-PK for poly(rG), but not for poly(rA), poly(rC) or poly(rU). This RNA binding affinity of DNA-PK can be ascribed to its Ku86 subunit. Consistently, poly(rG) most strongly stimulated the DNA-PK-catalyzed phosphorylation of NDH II. RNA interference studies revealed that a suppressed expression of NDH II altered the nuclear distribution of hnRNP C, while silencing DNA-PK changed the subnuclear distribution of NDH II and hnRNP C. These results support the view that DNA-PK can also function as an RNA-dependent protein kinase to regulate some aspects of RNA metabolism, such as RNA processing and transport.
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Affiliation(s)
- Suisheng Zhang
- Department of Biochemistry, Institute of Molecular Biotechnology, Postfach 100 813, D-07708 Jena, Germany
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