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Ji C, Chen L, Kaypaghian M. Effects of Combination of Ethanol With Ritonavir, Lopinavir or Darunavir on Expression and Localization of the ER-Associated Set Protein and Infection of HIV-1 Pseudovirus in Primary Human Cells. J Acquir Immune Defic Syndr 2024; 96:e6-e10. [PMID: 38771756 PMCID: PMC11110923 DOI: 10.1097/qai.0000000000003411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2024]
Affiliation(s)
- Cheng Ji
- Department of Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA
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Park J, Kim JY, Park JW, Kang JY, Oh H, Hahm J, Chae YC, Chakravarti D, Seo S. INHAT subunit SET/TAF-Iβ regulates PRC1-independent H2AK119 mono-ubiquitination via E3 ligase MIB1 in colon cancer. NAR Cancer 2023; 5:zcad050. [PMID: 37746636 PMCID: PMC10516711 DOI: 10.1093/narcan/zcad050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/21/2023] [Accepted: 09/11/2023] [Indexed: 09/26/2023] Open
Abstract
SET/TAF-Iβ, a subunit of the inhibitor of acetyltransferases (INHAT) complex, exhibits transcriptional repression activity by inhibiting histone acetylation. We find that SET/TAF-Iβ regulates mono-ubiquitination of histone H2A at lysine 119 (H2AK119ub), which is involved in polycomb-mediated transcriptional repression, in HCT116 cells. In this report, we demonstrate that SET/TAF-Iβ acts as an E2 ubiquitin-conjugating enzyme for PRC1-independent H2AK119ub. Furthermore, we identify that MIB1 is the E3 ligase partner for SET/TAF-Iβ using LC-MS/MS and in vitro ubiquitination assays. Transcriptome analysis reveals that SET/TAF-Iβ and MIB1 regulate the expression of genes related to DNA replication and cell cycle progression in HCT116 cells, and knockdown of either protein reduces proliferation of HCT116 cells by impeding cell cycle progression. Together, our study reveals a novel PRC1-independent epigenetic regulatory mechanism for H2AK119ub by SET/TAF-Iβ and MIB1 in colon cancer.
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Affiliation(s)
- Junyoung Park
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Ji-Young Kim
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Jin Woo Park
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Joo Young Kang
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Hyein Oh
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Ja Young Hahm
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Yun-Cheol Chae
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Debabrata Chakravarti
- Division of Reproductive Sciences in Medicine, Department of Obstetrics and Gynecology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sang Beom Seo
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 06974, Republic of Korea
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Casado-Combreras MÁ, Rivero-Rodríguez F, Elena-Real CA, Molodenskiy D, Díaz-Quintana A, Martinho M, Gerbaud G, González-Arzola K, Velázquez-Campoy A, Svergun D, Belle V, De la Rosa MA, Díaz-Moreno I. PP2A is activated by cytochrome c upon formation of a diffuse encounter complex with SET/TAF-Iβ. Comput Struct Biotechnol J 2022; 20:3695-3707. [PMID: 35891793 PMCID: PMC9293736 DOI: 10.1016/j.csbj.2022.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 07/04/2022] [Accepted: 07/04/2022] [Indexed: 11/25/2022] Open
Abstract
Intrinsic protein flexibility is of overwhelming relevance for intermolecular recognition and adaptability of highly dynamic ensemble of complexes, and the phenomenon is essential for the understanding of numerous biological processes. These conformational ensembles-encounter complexes-lack a unique organization, which prevents the determination of well-defined high resolution structures. This is the case for complexes involving the oncoprotein SET/template-activating factor-Iβ (SET/TAF-Iβ), a histone chaperone whose functions and interactions are significantly affected by its intrinsic structural plasticity. Besides its role in chromatin remodeling, SET/TAF-Iβ is an inhibitor of protein phosphatase 2A (PP2A), which is a key phosphatase counteracting transcription and signaling events controlling the activity of DNA damage response (DDR) mediators. During DDR, SET/TAF-Iβ is sequestered by cytochrome c (Cc) upon migration of the hemeprotein from mitochondria to the cell nucleus. Here, we report that the nuclear SET/TAF-Iβ:Cc polyconformational ensemble is able to activate PP2A. In particular, the N-end folded, globular region of SET/TAF-Iβ (a.k.a. SET/TAF-Iβ ΔC)-which exhibits an unexpected, intrinsically highly dynamic behavior-is sufficient to be recognized by Cc in a diffuse encounter manner. Cc-mediated blocking of PP2A inhibition is deciphered using an integrated structural and computational approach, combining small-angle X-ray scattering, electron paramagnetic resonance, nuclear magnetic resonance, calorimetry and molecular dynamics simulations.
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Key Words
- ANP32B, Acidic leucine-rich nuclear phosphoprotein family member B
- BTFA, 3-bromo-1,1,1-trifluoroacetone
- CD, Circular dichroism
- CDK9, Cyclin-dependent kinase 9
- CW, Continuous wave
- Cc, Cytochrome c
- Cytochrome c
- DDR, DNA damage response
- DEER, Double electron–electron resonance
- DLS, Dynamic light scattering
- DMEM, Dulbecco’s modified Eagle’s medium
- DNA, Deoxyribonucleic acid
- DTT, Dithiotreitol
- Dmax, Maximum dimension
- EDTA, Ethylenediamine tetraacetic acid
- EGTA, Ethyleneglycol tetraacetic acid
- EPR, Electron paramagnetic resonance
- Encounter complex
- FBS, Fetal bovine serum
- GUI, Graphical user interface
- HEK, Human embryonic kidney cells
- HRP, Horseradish peroxidase
- I2PP2A, Inhibitor 2 of the protein phosphatase 2A
- I3PP2A, Inhibitor 3 of the protein phosphatase 2A
- INTAC, Integrator-PP2A complex
- IPTG, Isopropyl-β-D-1-thiogalactopyranoside
- ITC, Isothermal titration calorimetry
- Ip/Id, Intensity ratio of NMR resonances between paramagnetic and diamagnetic samples
- LB, Luria-Bertani
- MD, Molecular dynamics
- MTS, (1-acetoxy-2,2,5,5-tetramethyl-δ-3-pyrroline-3-methyl) methanethiosulfonate
- MTSL, (1-oxyl-2,2,5,5-tetramethyl- δ −3-pyrroline-3-methyl) methanethiosulfonate
- MW, Molecular weight
- Molecular dynamics
- NAP1, Nucleosome assembly protein 1
- NAPL, Nucleosome assembly protein L
- NMA, Normal mode analysis
- NMR, Nuclear magnetic resonance
- NPT, Constant number, pressure and temperature
- NVT, Constant number, volume and temperature
- Nuclear magnetic resonance
- OD600, Optical density measured at 600 nm
- OPC, Optimal 3-charge, 4-point rigid water model
- PCR, Polymerase chain reaction
- PME, Particle mesh Ewald
- PMSF, Phenylmethylsulfonyl fluoride
- PP2A, Protein phosphatase 2A
- PRE, Paramagnetic relaxation enhancement
- PVDF, Polyvinylidene fluoride
- Protein phosphatase 2A
- RNA, Ribonucleic acid
- RNApol II, RNA polymerase II
- Rg, Radius of gyration
- SAXS, Small-angle X-ray scattering
- SC, Sample changer
- SDS-PAGE, Sodium dodecylsulfate-polyacrylamide gel electrophoresis
- SDSL, Site-directed spin labeling
- SEC, Size-exclusion chromatography
- SET/TAF-Iβ
- SET/TAF-Iβ ΔC, SET/template-activating factor-Iβ construct lacking its C-terminal domain
- SET/TAF-Iβ, SET/template-activating factor-Iβ
- SPRi, Surface plasmon resonance imaging
- TAF-Iα, Template-activating factor-Iα
- TPBS, Tween 20-phosphate buffered saline
- VPS75, Vacuolar protein sorting-associated protein 75
- WT, Wild type
- XRD, X-ray diffraction
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Affiliation(s)
- Miguel Á. Casado-Combreras
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
| | - Francisco Rivero-Rodríguez
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
| | - Carlos A. Elena-Real
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
- Centre de Biologie Structurale (CBS), INSERM, Centre National de la Recherche Scientifique (CNRS) and Université de Montpellier. 29 rue de Navacelles, 34090 Montpellier, France
| | - Dmitry Molodenskiy
- European Molecular Biology Laboratory, Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg, Germany
| | - Antonio Díaz-Quintana
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
| | - Marlène Martinho
- Aix Marseille Univ. Centre National de la Recherche Scientifique (CNRS), BIP UMR7281, Bioénergétique et Ingénierie des protéines, 13402 Marseille, France
| | - Guillaume Gerbaud
- Aix Marseille Univ. Centre National de la Recherche Scientifique (CNRS), BIP UMR7281, Bioénergétique et Ingénierie des protéines, 13402 Marseille, France
| | - Katiuska González-Arzola
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
| | - Adrián Velázquez-Campoy
- Institute of Biocomputation and Physic of Complex Systems (BIFI), Joint Unit GBsC-CSIC-BIFI, Universidad de Zaragoza. C. de Mariano Esquillor Gómez, Edificio I+D, 50018 Zaragoza, Spain
- Departamento de Bioquímica y Biología Molecular y Celular, Facultad de Ciencias, Universidad de Zaragoza, C. Pedro Cerbuna, 12, 50009 Zaragoza, Spain
- Instituto de Investigación Sanitaria de Aragón (IIS Aragon), Zaragoza, Spain
- Centro de Investigación Biomédica en Red en el Área Temática de Enfermedades Hepáticas y Digestivas (CIBERehd), C. de Melchor Fernández Almagro, 3, 28029 Madrid, Spain
| | - Dmitri Svergun
- European Molecular Biology Laboratory, Hamburg Outstation, c/o Deutsches Elektronen-Synchrotron, Notkestr. 85, 22607 Hamburg, Germany
| | - Valérie Belle
- Aix Marseille Univ. Centre National de la Recherche Scientifique (CNRS), BIP UMR7281, Bioénergétique et Ingénierie des protéines, 13402 Marseille, France
| | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
| | - Irene Díaz-Moreno
- Institute for Chemical Research (IIQ), Scientific Research Centre “Isla de la Cartuja” (cicCartuja), University of Seville and CSIC, Avda. Américo Vespucio, 49, 41092 Seville, Spain
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González‐Arzola K, Guerra‐Castellano A, Rivero‐Rodríguez F, Casado‐Combreras MÁ, Pérez‐Mejías G, Díaz‐Quintana A, Díaz‐Moreno I, De la Rosa MA. Mitochondrial cytochrome c shot towards histone chaperone condensates in the nucleus. FEBS Open Bio 2021; 11:2418-2440. [PMID: 33938164 PMCID: PMC8409293 DOI: 10.1002/2211-5463.13176] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022] Open
Abstract
Despite mitochondria being key for the control of cell homeostasis and fate, their role in DNA damage response is usually just regarded as an apoptotic trigger. However, growing evidence points to mitochondrial factors modulating nuclear functions. Remarkably, after DNA damage, cytochrome c (Cc) interacts in the cell nucleus with a variety of well-known histone chaperones, whose activity is competitively inhibited by the haem protein. As nuclear Cc inhibits the nucleosome assembly/disassembly activity of histone chaperones, it might indeed affect chromatin dynamics and histone deposition on DNA. Several histone chaperones actually interact with Cc Lys residues through their acidic regions, which are also involved in heterotypic interactions leading to liquid-liquid phase transitions responsible for the assembly of nuclear condensates, including heterochromatin. This relies on dynamic histone-DNA interactions that can be modulated by acetylation of specific histone Lys residues. Thus, Cc may have a major regulatory role in DNA repair by fine-tuning nucleosome assembly activity and likely nuclear condensate formation.
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Affiliation(s)
- Katiuska González‐Arzola
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Alejandra Guerra‐Castellano
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Francisco Rivero‐Rodríguez
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel Á. Casado‐Combreras
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Gonzalo Pérez‐Mejías
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Antonio Díaz‐Quintana
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Irene Díaz‐Moreno
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
| | - Miguel A. De la Rosa
- Institute for Chemical Research (IIQ)Scientific Research Centre Isla de la Cartuja (cicCartuja)University of Seville – CSICSpain
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Chen Z, Zhong J, Ren X, Liu W, Wu D, Chen C, Huang H, Huang X, Liu Y, Liu J. Involvement of a novel regulatory cascade consisting of SET-H3K18ac/H3K27ac-53BP1 in Cr(VI)-induced malignant transformation of 16HBE cells. Toxicol Lett 2020; 339:70-77. [PMID: 33370592 DOI: 10.1016/j.toxlet.2020.12.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 12/09/2020] [Accepted: 12/21/2020] [Indexed: 12/20/2022]
Abstract
Hexavalent chromium (Cr(VI)) is a well-established human carcinogen with DNA damaging effects. Recently we established a Cr(VI)-induced malignant transformation model from a human bronchial epithelial (16HBE) cell line, and in the transformed (16HBE-T) cells reduced levels of 53BP1 (critical for DNA repair) and the acetylated histone H3K18/27 (H3K18/27ac) were observed. In 16HBE-T cells SET (a multifunctional protein) was elevated by Cr(VI) through quantitative proteomics analysis. In the present study, we further explore the involvement of SET in the H3K18/27ac/53BP1 cascade in the 16HBE-T model, primarily by knockdown of SET. Bioinformatic analysis of the differentially expressed proteins indicated enrichment in histone modifications, in which SET was a major regulator. In 16HBE cells SET expression was enhanced by Cr(VI) in a concentration- and exposure duration-dependent manner. In 16HBE-T cells, SET knockdown showed the following effects: reversal of H3K18/27ac and 53BP1 levels, enhanced enrichment H3K18/27ac in 53BP1's promotor region, increase rate of apoptosis and cell cycle G0/G1 arrest (with or without Cr(VI) treatment), and reduced colony-forming efficiency. Finally, In comparison with benzo(a)pyrene-transformed (malignant, 16HBE-B) cells from 16HBE where no changes in H3K18/27ac, 53BP1 or SET were observed, while the H3K18/27ac/53BP1 cascade was downregulated and SET upregulated in 16HBE-T cells, as compared with the parental 16HBE cells; thus the changes in 16HBE-T might be a specific effect of Cr(VI). In conclusion, our results suggest that SET may be involved in the malignant cell transformation, through inhibiting the H3K18/27ac/53BP1 cascade, at least in the 16HBE cell model.
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Affiliation(s)
- Zhihong Chen
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China; Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Jiacheng Zhong
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Xiaohu Ren
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Wei Liu
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Desheng Wu
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Chongyang Chen
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Haiyan Huang
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Xinfeng Huang
- Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055
| | - Yungang Liu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China
| | - Jianjun Liu
- Department of Toxicology, School of Public Health, Southern Medical University, Guangzhou, China; Shenzhen Key Laboratory of Modern Toxicology, Shenzhen Medical Key Discipline of Health Toxicology (2020-2024), Shenzhen Center for Disease Control and Prevention, Shenzhen, China, 518055.
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Bui PL, Nishimura K, Seminario Mondejar G, Kumar A, Aizawa S, Murano K, Nagata K, Hayashi Y, Fukuda A, Onuma Y, Ito Y, Nakanishi M, Hisatake K. Template Activating Factor-I α Regulates Retroviral Silencing during Reprogramming. Cell Rep 2019; 29:1909-1922.e5. [DOI: 10.1016/j.celrep.2019.10.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 08/02/2019] [Accepted: 10/01/2019] [Indexed: 02/07/2023] Open
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7
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Distribution of SET/I2PP2A protein in gastrointestinal tissues. PLoS One 2019; 14:e0222845. [PMID: 31557212 PMCID: PMC6762106 DOI: 10.1371/journal.pone.0222845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Accepted: 09/09/2019] [Indexed: 11/21/2022] Open
Abstract
SET (also called I2PP2A and TIF-1) is a multi-functional protein that regulates a variety of cell signaling including nucleosome assembly, histone binding, and tumorigenesis. Elevated SET protein levels are observed in various human tumors, and are correlated with poor prognosis and drug-resistance. We recently reported that SET protein levels in cancer cells were positively correlated with poor prognosis of gastric cancer patients. Using immunohistochemistry, SET protein was observed not only in cancer cells, but also in some interstitial cells. However, the tissue distribution of SET has not been investigated. Here we performed co-immunofluorescent staining to characterize SET protein distribution in gastrointestinal tissues. We found that even though the positive rate is much lower than epithelial cells, SET protein is also expressed in non-epithelial cells, such as monocytes/macrophages, neural cells, myofibroblasts, and smooth muscle cells. Our results indicate an extensive role of SET in a variety of cell types.
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Zhong J, Ren X, Chen Z, Zhang H, Zhou L, Yuan J, Li P, Chen X, Liu W, Wu D, Yang X, Liu J. miR-21-5p promotes lung adenocarcinoma progression partially through targeting SET/TAF-Iα. Life Sci 2019; 231:116539. [PMID: 31176779 DOI: 10.1016/j.lfs.2019.06.014] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 05/29/2019] [Accepted: 06/05/2019] [Indexed: 01/15/2023]
Abstract
OBJECTIVE Although SET(I2PP2A) and miRNAs are reported to play a pivotal role in lung cancer, the underlying mechanisms have remained obscure. To address this issue, we investigated how miRNAs and SET participate in the progression of lung cancer. METHODS miRNAs that target SET were predicted from multiple miRNA databases. Three human NSCLC cell lines and two normal lung cell lines were used to evaluate aberrant miRNA and SET expressions. A dual luciferase reporter assay system was employed to verify the interaction between miRNA and SET. Stable miRNA knockdown and SET overexpression in A549 cells were achieved through lentivirus transfection; the corresponding influences on lung cancer progression were also examined. RESULTS In this study, A549 was the sole cell line to lack SET/TAF-Iα expression, which was inversely correlated with the up-regulation of miR-21-5p. SET was subsequently revealed as the direct target site of miR-21-5p in A549 cells. The stable miR-21-5p knockdown and SET/TAF-Iα overexpression were shown to markedly enhance the expression of SET/TAF-Iα and to inhibit the migration, invasion, proliferation as well as the in vivo tumorigenicity of A549 cells. CONCLUSION We suggest that SET/TAF-Iα might be a tumor suppressing factor regulated by miR-21-5p in lung adenocarcinoma. This might provide a target for lung adenocarcinoma therapy.
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Affiliation(s)
- Jiacheng Zhong
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Xiaohu Ren
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Zhihong Chen
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Hang Zhang
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Li Zhou
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Jianhui Yuan
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Ping Li
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Xiao Chen
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Wei Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Desheng Wu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Xifei Yang
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China
| | - Jianjun Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen 518055, Guangdong, China.
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De Palma RM, Parnham SR, Li Y, Oaks JJ, Peterson YK, Szulc ZM, Roth BM, Xing Y, Ogretmen B. The NMR-based characterization of the FTY720-SET complex reveals an alternative mechanism for the attenuation of the inhibitory SET-PP2A interaction. FASEB J 2019; 33:7647-7666. [PMID: 30917007 DOI: 10.1096/fj.201802264r] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The su(var)3-9, enhancer of zeste, trithorax (SET)/inhibitor 2 of protein phosphatase 2A (PP2A) oncoprotein binds and inhibits PP2A, composed of various isoforms of scaffolding, regulatory, and catalytic subunits. Targeting SET with a sphingolipid analog drug fingolimod (FTY720) or ceramide leads to the reactivation of tumor suppressor PP2A. However, molecular details of the SET-FTY720 or SET-ceramide, and mechanism of FTY720-dependent PP2A activation, remain unknown. Here, we report the first in solution examination of the SET-FTY720 or SET-ceramide complexes by NMR spectroscopy. FTY720-ceramide binding resulted in chemical shifts of residues residing at the N terminus of SET, preventing its dimerization or oligomerization. This then released SET from PP2ACα, resulting in PP2A activation, while monomeric SET remained associated with the B56γ. Our data also suggest that the PP2A holoenzyme, composed of PP2A-Aβ, PP2A-B56γ, and PP2ACα subunits, is selectively activated in response to the formation of the SET-FTY720 complex in A549 cells. Various PP2A-associated downstream effector proteins in the presence or absence of FTY720 were then identified by stable isotope labeling with amino cells in cell culture, including tumor suppressor nonmuscle myosin IIA. Attenuation of FTY720-SET association by point mutations of residues that are involved in FTY720 binding or dephosphorylation of SET at Serine 171, enhanced SET oligomerization and the formation of the SET-PP2A inhibitory complex, leading to resistance to FTY720-dependent PP2A activation.-De Palma, R. M., Parnham, S. R., Li, Y., Oaks, J. J., Peterson, Y. K., Szulc, Z. M., Roth, B. M., Xing, Y., Ogretmen, B. The NMR-based characterization of the FTY720-SET complex reveals an alternative mechanism for the attenuation of the inhibitory SET-PP2A interaction.
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Affiliation(s)
- Ryan M De Palma
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Stuart R Parnham
- Department of Biochemistry and Biophysics, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA
| | - Yitong Li
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | | | - Yuri K Peterson
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Zdzislaw M Szulc
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Braden M Roth
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Yongna Xing
- McArdle Laboratory for Cancer Research, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina, USA.,Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, USA
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10
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Tu W, Yang B, Leng X, Pei X, Xu J, Liu M, Dong Q, Tao D, Lu Y, Liu Y, Yang Y. Testis-specific protein, Y-linked 1 activates PI3K/AKT and RAS signaling pathways through suppressing IGFBP3 expression during tumor progression. Cancer Sci 2019; 110:1573-1586. [PMID: 30815935 PMCID: PMC6501036 DOI: 10.1111/cas.13984] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 02/19/2019] [Accepted: 02/24/2019] [Indexed: 02/05/2023] Open
Abstract
The testis‐specific protein, Y‐linked 1 (TSPY1), a newly recognized cancer/testis antigen, has been suggested to accelerate tumor progression. However, the mechanisms underlying TSPY1 cancer‐related function remain limited. By mining the RNA sequencing data of lung and liver tumors from The Cancer Genome Atlas, we found frequent ectopic expression of TSPY1 in lung adenocarcinoma (LUAD) and liver hepatocellular carcinoma (LIHC), and the male‐specific protein was associated with higher mortality rate and worse overall survival in patients with LUAD and LIHC. Overexpression of TSPY1 promotes cell proliferation, invasiveness, and cycle transition and inhibits apoptosis, whereas TSPY1 knockdown has the opposite effects on these cancer cell phenotypes. Transcriptomic analysis revealed the involvement of TSPY1 in PI3K/AKT and RAS signaling pathways in both LUAD and LIHC cells, which was further confirmed by the increase in the levels of phosphorylated proteins in the PI3K‐AKT and RAS signaling pathways in TSPY1‐overexpressing cancer cells, and by the suppression on the activity of these two pathways in TSPY1‐knockdown cells. Further investigation identified that TSPY1 could directly bind to the promoter of insulin growth factor binding protein 3 (IGFBP3) to inhibit IGFBP3 expression and that downregulation of IGFBP3 increased the activity of PI3K/AKT/mTOR/BCL2 and RAS/RAF/MEK/ERK/JUN signaling in LUAD and LIHC cells. Taken together, the observations reveal a novel mechanism by which TSPY1 could contribute to the progression of LUAD and LIHC. Our finding is of importance for evaluating the potential of TSPY1 in immunotherapy of male tumor patients with TSPY1 expression.
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Affiliation(s)
- Wenling Tu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Bo Yang
- Department of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Xiangyou Leng
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Xue Pei
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Jinyan Xu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Mohan Liu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Qiang Dong
- Department of Urology, West China Hospital, Sichuan University, Chengdu, China
| | - Dachang Tao
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Yongjie Lu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Yunqiang Liu
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
| | - Yuan Yang
- Department of Medical Genetics, State Key Laboratory of Biotherapy, West China Hospital, West China Medical School, Sichuan University, Chengdu, China
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11
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Kon N, Wang D, Gu W. Loss of SET reveals both the p53-dependent and the p53-independent functions in vivo. Cell Death Dis 2019; 10:237. [PMID: 30858352 PMCID: PMC6411979 DOI: 10.1038/s41419-019-1484-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 01/28/2019] [Accepted: 02/20/2019] [Indexed: 11/30/2022]
Abstract
Our previous study showed that the oncoprotein SET acts as a new reader of unacetylated p53 for transcriptional repression. To further elucidate the physiological significance of SET in vivo, we generated set knockout mice. Set knockout mice died during embryonic development between day 11.5 and day 12.5 post coitum, exhibiting cardiac edema and open neural tube, among other developmental defects. Further analyses revealed that loss of SET leads to upregulation of p53 target genes including p21 and puma without any obvious effect on p53 stability in set knockout embryos. Notably, the developmental defects of set knockout mice were significantly, but nonetheless partially, rescued by concomitant deletion of p53. The failure to obtain fully live set/p53 double knockout mice suggested that p53-independent targets of SET also contribute to the embryonic lethality of set knockout mice. Indeed, we found that FOXO1 acts as an important target of SET and that SET-mediated regulation of FOXO1 is also acetylation-dependent. Taken together, these data underscore the importance of SET oncoprotein during embryonic development and reveal both of the p53-dependent and the p53-independent functions of SET in vivo.
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Affiliation(s)
- Ning Kon
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, College of Physicians & Surgeons, Columbia University, 1130 Nicholas Ave, New York, NY, 10032, USA
| | - Donglai Wang
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, College of Physicians & Surgeons, Columbia University, 1130 Nicholas Ave, New York, NY, 10032, USA.,National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, Beijing, 100005, China.,Department of Medical Genetics, School of Basic Medicine, Peking Union Medical College, Beijing, 100005, China
| | - Wei Gu
- Institute for Cancer Genetics, Department of Pathology and Cell Biology, and Herbert Irving Comprehensive Cancer Center, College of Physicians & Surgeons, Columbia University, 1130 Nicholas Ave, New York, NY, 10032, USA.
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12
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Lu W, Chen Z, Ren X, Liu W, Deng R, Yuan J, Huang X, Zhu W, Liu J. SET promotes H2Ak9 acetylation by suppressing HDAC1 in trichloroethylene-induced hepatic cytotoxicity. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 59:125-131. [PMID: 29579541 DOI: 10.1016/j.etap.2018.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 03/13/2018] [Accepted: 03/14/2018] [Indexed: 06/08/2023]
Abstract
Trichloroethylene (TCE) was widely used as an industrial solvent which could cause severe liver damage. The histone chaperone SET have been identified as an important mediator of TCE-induced hepatic cytotoxicity in our previous study; however, the underlying regulatory mechanisms remain poorly understood. In this study, we found a total of 136 histone acetylation sites involved in TCE-induced hepatic cytotoxicity with the technique of Triton-acid-urea polyacrylamide gel electrophoresis (TAU-PAGE) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Importantly, 17 histone acetylation sites were revealed to be mediated by SET in TCE-induced cytotoxicity. The acetylation of histone H2AK9 (H2AK9ac) was further validated by Western-blot analysis. The data showed that TCE treatment increased the acetylation of H2AK9 in hepatic L-02 cell and decreased the one in SET-knockdown L-02 cells. Besides, levels of the histone deacetylases (HDACs, including HDAC1, HDAC2, and HDAC3) was also analyzed. Interestingly, the level of HDAC1 was aberrantly suppressed in TCE-treated L-02 cells while enhanced in SET-knockdown L-02 cells. To further explore the potential role of HDAC1 in SET-mediated hepatic cytotoxicity of TCE, we employed RNA interference (RNAi) to knockdown HDAC1 in both wide type L-02 and SET-knockdown cells. The results showed that the siRNA inhibition of HDAC1 increased the acetylation of H2AK9. Taken together, our data suggested that SET promoted the acetylation of H2AK9 via suppressing the level of HDAC1, which was involved in SET-mediated hepatic cytotoxicity of TCE.
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Affiliation(s)
- Weixue Lu
- School of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China; Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Zhihong Chen
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China; School of Public Health, Southern Medical University, Tonghe District, Guangzhou, 510515, China
| | - Xiaohu Ren
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Wei Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Rongxia Deng
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Jianhui Yuan
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Xinfeng Huang
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China
| | - Weiguo Zhu
- School of Chemistry, Xiangtan University, Yuhu District, Xiangtan, 411105, Hunan, China; School of Materials Science and Engineering, Jiangsu Collaboration Innovation Center of Photovoltaic Science and Engineering, Changzhou University, Wujin District, Changzhou 213164, China.
| | - Jianjun Liu
- Institute of Toxicology, Shenzhen Center for Disease Control and Prevention, No 8 Longyuan Road, Nanshan District, Shenzhen, 518055, Guangdong, China.
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13
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Zhang B, Ma W, Zhu Q, Xu W, Gao L, Xu B, Xu S, Gao C, Gao L, Liu J, Cui Y. The SET protein promotes androgen production in testicular Leydig cells. Andrology 2018; 6:478-487. [PMID: 29481720 PMCID: PMC6001814 DOI: 10.1111/andr.12476] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 01/22/2018] [Accepted: 01/23/2018] [Indexed: 12/31/2022]
Abstract
Approximately 40% of middle‐aged men exhibit symptoms of late‐onset hypogonadism (LOH). However, the mechanism of androgen deficiency is still currently unclear. As shown in our previous studies, the SET protein is expressed in testicular Leydig cells and ovarian granule cells. This study was designed to investigate the effect of the SET protein on androgen production in Leydig cells. The AdCMV/SET and AdH1siRNA/SET adenoviruses were individually transduced into a cultured mouse Leydig cell line (mLTC‐1) with or without human chorionic gonadotropin (HCG) stimulation in vitro. The primary mouse Leydig cells were used to confirm the main data from mLTC‐1 cells. The SET protein was expressed in the cytoplasm and nucleus of mLTC‐1 cells. Testosterone production was significantly increased in mLTC‐1 cells overexpressing the SET protein compared with the control group (p < 0.05), whereas testosterone production was significantly decreased in the SET knockdown mLTC‐1 cells (p < 0.05). Consistent with the testosterone levels, the expression levels of the steroidogenic acute regulatory (StAR) and cytochrome P450c17α‐hydroxylase (CYP17a1) mRNAs and proteins synchronously changed according to the expression level of the SET protein. Interestingly, the expression of the SET protein was significantly increased in the mLTC‐1 cells stimulated with 0.04 and 0.1 U/mL hCG. In the mLTC‐1 cells transfected with AdH1siRNA/SET and concurrently stimulated with 0.1 U/mL hCG, both testosterone production and StAR expression were significantly lower than in the cells without SET knockdown (p < 0.05). In conclusion, the SET protein participates in regulating testosterone production by increasing the expression of StAR and CYP17a1, and it may be a downstream factor of the classic luteinizing hormone (LH)/luteinizing hormone receptor (LHR) signaling pathway. This study improves our understanding of the intracellular mechanism of testicular steroidogenesis and the pathophysiological mechanism of LOH in the aging male.
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Affiliation(s)
- B Zhang
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - W Ma
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Q Zhu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - W Xu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - L Gao
- Department of Obstetrics and Gynecology, Clinical Medical College of Yangzhou University, Yangzhou, China
| | - B Xu
- Department of Gynecology, Second Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - S Xu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - C Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - L Gao
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - J Liu
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
| | - Y Cui
- State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, China
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14
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Ekmekci SS, Ekmekci CG, Kandilci A, Gulec C, Akbiyik M, Emrence Z, Abaci N, Karakas Z, Agaoglu L, Unuvar A, Anak S, Devecioglu O, Ustek D, Grosveld G, Ozbek U. SET Oncogene is Upregulated in Pediatric Acute Lymphoblastic Leukemia. TUMORI JOURNAL 2018; 98:252-6. [DOI: 10.1177/030089161209800212] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Aims and background The SET gene is a target of chromosomal translocations in acute leukemia and encodes a widely expressed multifunctional phosphoprotein. It has been shown that SET is upregulated in BCR-ABL1-positive cell lines, patient-derived chronic myeloid leukemia CD34-positive cells, and some solid tumors. Methods and study design We determined the expression level of SET in 59 pediatric acute lymphoblastic leukemia patients who were BCR-ABL-negative using quantitative real-time reverse-transcriptase-polymerase chain reaction. Results We showed that SET expression was significantly upregulated in 96.5% of B-acute lymphoblastic leukemia (28 of 29; 16.6 fold) and 93% of T-acute lymphoblastic leukemia (28 of 30; 47.6 fold) patients. This upregulation was not associated with any clinical features or overall and relapse-free survival. Conclusions Our results showed that SET is significantly overexpressed in pediatric acute lymphoblastic leukemia samples, and an increased level of SET might contribute to leukemic process.
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Affiliation(s)
- Sema Sirma Ekmekci
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
| | - Cumhur G Ekmekci
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
| | - Ayten Kandilci
- Gebze Institute of Technology, Department of Molecular Biology and Genetics, Kocaeli
| | - Cagri Gulec
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Meral Akbiyik
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Zeliha Emrence
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
| | - Neslihan Abaci
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
| | - Zeynep Karakas
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Leyla Agaoglu
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Aysegul Unuvar
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Sema Anak
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Omer Devecioglu
- Istanbul University, Istanbul Medical Faculty, Department of Pediatrics, Istanbul, Turkey
| | - Duran Ustek
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
| | - Gerard Grosveld
- St. Jude Children's Research Hospital, Department of Genetics, Memphis TN, USA
| | - Ugur Ozbek
- Istanbul University, Institute of Experimental Medicine, Department of Genetics, Istanbul
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15
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Assembly and remodeling of viral DNA and RNA replicons regulated by cellular molecular chaperones. Biophys Rev 2017; 10:445-452. [PMID: 29170971 DOI: 10.1007/s12551-017-0333-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/07/2017] [Indexed: 12/12/2022] Open
Abstract
A variety of cellular reactions mediated by interactions among proteins and nucleic acids requires a series of proteins called molecular chaperones. The viral genome encodes relatively few kinds of viral proteins and, therefore, host-derived cellular factors are required for virus proliferation. Here we discuss those cellular proteins known as molecular chaperones, which are essential for the assembly of functional viral DNA/RNA replicons. The function of these molecular chaperones in the cellular context is also discussed.
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16
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Alternative SET/TAFI Promoters Regulate Embryonic Stem Cell Differentiation. Stem Cell Reports 2017; 9:1291-1303. [PMID: 28966118 PMCID: PMC5639460 DOI: 10.1016/j.stemcr.2017.08.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 08/27/2017] [Accepted: 08/28/2017] [Indexed: 01/21/2023] Open
Abstract
Embryonic stem cells (ESCs) are regulated by pluripotency-related transcription factors in concert with chromatin regulators. To identify additional stem cell regulators, we screened a library of endogenously labeled fluorescent fusion proteins in mouse ESCs for fluorescence loss during differentiation. We identified SET, which displayed a rapid isoform shift during early differentiation from the predominant isoform in ESCs, SETα, to the primary isoform in differentiated cells, SETβ, through alternative promoters. SETα is selectively bound and regulated by pluripotency factors. SET depletion causes proliferation slowdown and perturbed neuronal differentiation in vitro and developmental arrest in vivo, and photobleaching methods demonstrate SET's role in maintaining a dynamic chromatin state in ESCs. This work identifies an important regulator of pluripotency and early differentiation, which is controlled by alternative promoter usage. We identify SETα to be rapidly downregulated during ESC differentiation SETα is regulated by pluripotency factors and replaced by SETβ during differentiation SETα/SETβ switch is crucial for ESC differentiation SETα regulates chromatin plasticity in ESCs
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17
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Mody HR, Hung SW, Naidu K, Lee H, Gilbert CA, Hoang TT, Pathak RK, Manoharan R, Muruganandan S, Govindarajan R. SET contributes to the epithelial-mesenchymal transition of pancreatic cancer. Oncotarget 2017; 8:67966-67979. [PMID: 28978088 PMCID: PMC5620228 DOI: 10.18632/oncotarget.19067] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 05/22/2017] [Indexed: 02/07/2023] Open
Abstract
Pancreatic cancer has a devastating prognosis due to 80-90% of diagnostic cases occurring when metastasis has already presented. Activation of the epithelial-mesenchymal transition (EMT) is a prerequisite for metastasis because it allows for the dissemination of tumor cells to blood stream and secondary organs. Here, we sought to determine the role of SET oncoprotein, an endogenous inhibitor of PP2A, in EMT and pancreatic tumor progression. Among the two major isoforms of SET (isoform 1 and isoform 2), higher protein levels of SET isoform 2 were identified in aggressive pancreatic cancer cell lines. Overexpressing SET isoform 2, and to a lesser extent SET isoform 1, in epithelial cell lines promoted EMT-like features by inducing mesenchymal characteristics and promoting cellular proliferation, migration, invasion, and colony formation. Consistently, knockdown of SET isoforms in the mesenchymal cell line partially resisted these characteristics and promoted epithelial features. SET-induced EMT was likely facilitated by increased N-cadherin overexpression, decreased PP2A activity and/or increased expression of key EMT-driving transcription factors. Additionally, SET overexpression activated the Rac1/JNK/c-Jun signaling pathway that induced transcriptional activation of N-cadherin expression. In vivo, SET isoform 2 overexpression significantly correlated with increased N-cadherin in human PDAC and to tumor burden and metastatic ability in an orthotopic mouse tumor model. These findings identify a new role for SET in cancer and have implications for the design and targeting of SET for intervening pancreatic tumor progression.
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Affiliation(s)
- Hardik R Mody
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA.,Department of Pharmaceutical and Biomedical Sciences, The University of Georgia, Athens, GA, USA
| | - Sau Wai Hung
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia, Athens, GA, USA
| | - Kineta Naidu
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, USA
| | - Haesung Lee
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, USA
| | - Caitlin A Gilbert
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, USA
| | - Toan Thanh Hoang
- Department of Biochemistry and Molecular Biology, The University of Georgia, Athens, GA, USA
| | - Rakesh K Pathak
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA
| | - Radhika Manoharan
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA
| | - Shanmugam Muruganandan
- Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA
| | - Rajgopal Govindarajan
- The Comprehensive Cancer Center, The Ohio State University, Columbus, OH, USA.,Division of Pharmaceutics and Pharmaceutical Chemistry, The Ohio State University, Columbus, OH, USA.,Department of Pharmaceutical and Biomedical Sciences, The University of Georgia, Athens, GA, USA
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18
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Kajitani K, Kato K, Nagata K. Histone H1 chaperone activity of TAF-I is regulated by its subtype-dependent intramolecular interaction. Genes Cells 2017; 22:334-347. [PMID: 28251751 DOI: 10.1111/gtc.12478] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Accepted: 01/14/2017] [Indexed: 11/29/2022]
Abstract
Linker histone H1 is involved in the regulation of gene activity through the maintenance of higher-order chromatin structure. Previously, we have shown that template activating factor-I (TAF-I or protein SET) is involved in linker histone H1 dynamics as a histone H1 chaperone. In human and murine cells, two TAF-I subtypes exist, namely TAF-Iα and TAF-Iβ. TAF-I has a highly acidic amino acid cluster in its C-terminal region and forms homo- or heterodimers through its dimerization domain. Both dimer formation and the C-terminal region of TAF-I are essential for the histone chaperone activity. TAF-Iα exhibits less histone chaperone activity compared with TAF-Iβ even though TAF-Iα and β differ only in their N-terminal regions. However, it is unclear how subtype-specific TAF-I activities are regulated. Here, we have shown that the N-terminal region of TAF-Iα autoinhibits its histone chaperone activity via intramolecular interaction with its C-terminal region. When the interaction between the N- and C-terminal regions of TAF-Iα is disrupted, TAF-Iα shows a histone chaperone activity similar to that of TAF-Iβ. Taken together, these results provide mechanistic insights into the concept that fine tuning of TAF-I histone H1 chaperone activity relies on the subtype compositions of the TAF-I dimer.
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Affiliation(s)
- Kaori Kajitani
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.,University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan
| | - Kohsuke Kato
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan.,University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan
| | - Kyosuke Nagata
- University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305-8575, Japan
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19
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Jiang SW, Xu S, Chen H, Liu X, Tang Z, Cui Y, Liu J. Pathologic significance of SET/I2PP2A-mediated PP2A and non-PP2A pathways in polycystic ovary syndrome (PCOS). Clin Chim Acta 2017; 464:155-159. [PMID: 27836688 DOI: 10.1016/j.cca.2016.11.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Revised: 11/06/2016] [Accepted: 11/07/2016] [Indexed: 02/05/2023]
Abstract
SET (SE translocation, SET), a constitutive inhibitor of protein phosphatase 2A (PP2A), is a multifunctional oncoprotein involved in DNA replication, histone modification, nucleosome assembly, gene transcription and cell proliferation. It is widely expressed in human tissues including the gonadal system and brain. Intensive studies have shown that overexpressed SET plays an important role in the development of Alzheimer's disease (AD), and may also contribute to the malignant transformation of breast and ovarian cancers. Recent studies indicated that through interaction with PP2A, SET may upregulate androgen biosynthesis and contribute to hyperandrogenism in polycystic ovary syndrome (PCOS) patients. This review article summarizes data concerning the SET expression in ovaries from PCOS and normal women, and analyzes the role/regulatory mechanism of SET for androgen biosynthesis in PCOS, as well as the significance of this action in the development of PCOS. The potential value of SET-triggered pathway as a therapeutic target and the application of anti-SET reagents for treating hyperandrogenism in PCOS patients are also discussed.
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Affiliation(s)
- Shi-Wen Jiang
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital, Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China; Department of Biomedical Science, Mercer University School of Medicine, Savannah, GA, USA.
| | - Siliang Xu
- Department of Biomedical Science, Mercer University School of Medicine, Savannah, GA, USA; The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Haibin Chen
- Department of Histology and Embryology, Shantou University Medical College, Shantou, Guangdong 515000, China
| | - Xiaoqiang Liu
- The Third People's Hospital of Qingdao, Department of Obstetrics and Gynecology, Qingdao, Shandong 266041, China; Department of Medical Genetics and Developmental Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Zuoqing Tang
- Department of Medical Genetics, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yugui Cui
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China
| | - Jiayin Liu
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, Jiangsu 210029, China.
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The zebrafish homologs of SET/I2PP2A oncoprotein: expression patterns and insights into their physiological roles during development. Biochem J 2016; 473:4609-4627. [PMID: 27754889 DOI: 10.1042/bcj20160523] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 10/13/2016] [Accepted: 10/17/2016] [Indexed: 01/12/2023]
Abstract
The oncoprotein SET/I2PP2A (protein phosphatase 2A inhibitor 2) participates in various cellular mechanisms such as transcription, cell cycle regulation and cell migration. SET is also an inhibitor of the serine/threonine phosphatase PP2A, which is involved in the regulation of cell homeostasis. In zebrafish, there are two paralogous set genes that encode Seta (269 amino acids) and Setb (275 amino acids) proteins which share 94% identity. We show here that seta and setb are similarly expressed in the eye, the otic vesicle, the brain and the lateral line system, as indicated by in situ hybridization labeling. Whole-mount immunofluorescence analysis revealed the expression of Seta/b proteins in the eye retina, the olfactory pit and the lateral line neuromasts. Loss-of-function studies using antisense morpholino oligonucleotides targeting both seta and setb genes (MOab) resulted in increased apoptosis, reduced cell proliferation and morphological defects. The morphant phenotypes were partially rescued when MOab was co-injected with human SET mRNA. Knockdown of setb with a transcription-blocking morpholino oligonucleotide (MOb) resulted in phenotypic defects comparable with those induced by setb gRNA (guide RNA)/Cas9 [CRISPR (clustered regularly interspaced short palindromic repeats)-associated 9] injections. In vivo labeling of hair cells showed a significantly decreased number of neuromasts in MOab-, MOb- and gRNA/Cas9-injected embryos. Microarray analysis of MOab morphant transcriptome revealed differential expression in gene networks controlling transcription in the sensory organs, including the eye retina, the ear and the lateral line. Collectively, our results suggest that seta and setb are required during embryogenesis and play roles in the zebrafish sensory system development.
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Regulation of Cellular Dynamics and Chromosomal Binding Site Preference of Linker Histones H1.0 and H1.X. Mol Cell Biol 2016; 36:2681-2696. [PMID: 27528617 DOI: 10.1128/mcb.00200-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 08/08/2016] [Indexed: 01/01/2023] Open
Abstract
Linker histones play important roles in the genomic organization of mammalian cells. Of the linker histone variants, H1.X shows the most dynamic behavior in the nucleus. Recent research has suggested that the linker histone variants H1.X and H1.0 have different chromosomal binding site preferences. However, it remains unclear how the dynamics and binding site preferences of linker histones are determined. Here, we biochemically demonstrated that the DNA/nucleosome and histone chaperone binding activities of H1.X are significantly lower than those of other linker histones. This explains why H1.X moves more rapidly than other linker histones in vivo Domain swapping between H1.0 and H1.X suggests that the globular domain (GD) and C-terminal domain (CTD) of H1.X independently contribute to the dynamic behavior of H1.X. Our results also suggest that the N-terminal domain (NTD), GD, and CTD cooperatively determine the preferential binding sites, and the contribution of each domain for this determination is different depending on the target genes. We also found that linker histones accumulate in the nucleoli when the nucleosome binding activities of the GDs are weak. Our results contribute to understanding the molecular mechanisms of dynamic behaviors, binding site selection, and localization of linker histones.
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Gupta N, Thakker S, Verma SC. KSHV encoded LANA recruits Nucleosome Assembly Protein NAP1L1 for regulating viral DNA replication and transcription. Sci Rep 2016; 6:32633. [PMID: 27599637 PMCID: PMC5013526 DOI: 10.1038/srep32633] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/11/2016] [Indexed: 11/17/2022] Open
Abstract
The establishment of latency is an essential for lifelong persistence and pathogenesis of Kaposi’s sarcoma-associated herpesvirus (KSHV). Latency-associated nuclear antigen (LANA) is the most abundantly expressed protein during latency and is important for viral genome replication and transcription. Replication-coupled nucleosome assembly is a major step in packaging the newly synthesized DNA into chromatin, but the mechanism of KSHV genome chromatinization post-replication is not understood. Here, we show that nucleosome assembly protein 1-like protein 1 (NAP1L1) associates with LANA. Our binding assays revealed an association of LANA with NAP1L1 in KSHV-infected cells, which binds through its amino terminal domain. Association of these proteins confirmed their localization in specific nuclear compartments of the infected cells. Chromatin immunoprecipitation assays from NAP1L1-depleted cells showed LANA-mediated recruitment of NAP1L1 at the terminal repeat (TR) region of the viral genome. Presence of NAP1L1 stimulated LANA-mediated DNA replication and persistence of a TR-containing plasmid. Depletion of NAP1L1 led to a reduced nucleosome positioning on the viral genome. Furthermore, depletion of NAP1L1 increased the transcription of viral lytic genes and overexpression decreased the promoter activities of LANA-regulated genes. These results confirmed that LANA recruitment of NAP1L1 helps in assembling nucleosome for the chromatinization of newly synthesized viral DNA.
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Affiliation(s)
- Namrata Gupta
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Suhani Thakker
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
| | - Subhash C Verma
- Department of Microbiology and Immunology, School of Medicine, University of Nevada, Reno, NV 89557, USA
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Abstract
SET is elevated and mislocalized in the neuronal cytoplasm in brains of Alzheimer's disease (AD) and Down syndrome (DS) patients. Cytoplasm SET leads to inhibition of protein phosphatase 2A and is involved in the tau pathology. However, the regulation of SET gene expression remains elusive. In the present study, we cloned a 1399-bp segment of the 5' flanking region of the human SET gene and identified that the transcription start site (TSS) of SET transcript 1 is located at 123 bp upstream of the translation start site ATG in exon 1. Sequence analysis reveals several putative regulatory elements including NFkB, Sp1, and HSE. Luciferase assay and electrophoretic mobility shift assay (EMSA) identified a functional cis-acting NFkB-responsive element in the SET gene promoter. Overexpression and activation of NFkB upregulate transcription of SET isoform 1 but not isoform 2, indicating that the expression of these two isoforms is differentially regulated. The results demonstrate that NFkB plays an important role in regulation of the human SET gene expression. Our findings suggest that oxidative stress and inflammatory responses could result in abnormal SET gene expression, contributing to the tauopathy in AD pathogenesis.
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MYC-dependent recruitment of RUNX1 and GATA2 on the SET oncogene promoter enhances PP2A inactivation in acute myeloid leukemia. Oncotarget 2016; 8:53989-54003. [PMID: 28903318 PMCID: PMC5589557 DOI: 10.18632/oncotarget.9840] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/22/2016] [Indexed: 01/15/2023] Open
Abstract
The SET (I2PP2A) oncoprotein is a potent inhibitor of protein phosphatase 2A (PP2A) that regulates many cell processes and important signaling pathways. Despite the importance of SET overexpression and its prognostic impact in both hematologic and solid tumors, little is known about the mechanisms involved in its transcriptional regulation. In this report, we define the minimal promoter region of the SET gene, and identify a novel multi-protein transcription complex, composed of MYC, SP1, RUNX1 and GATA2, which activates SET expression in AML. The role of MYC is crucial, since it increases the expression of the other three transcription factors of the complex, and supports their recruitment to the promoter of SET. These data shed light on a new regulatory mechanism in cancer, in addition to the already known PP2A-MYC and SET-PP2A. Besides, we show that there is a significant positive correlation between the expression of SET and MYC, RUNX1, and GATA2 in AML patients, which further endorses our results. Altogether, this study opens new directions for understanding the mechanisms that lead to SET overexpression, and demonstrates that MYC, SP1, RUNX1 and GATA2 are key transcriptional regulators of SET expression in AML.
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Sugiyama K, Kawaguchi A, Okuwaki M, Nagata K. pp32 and APRIL are host cell-derived regulators of influenza virus RNA synthesis from cRNA. eLife 2015; 4. [PMID: 26512887 PMCID: PMC4718810 DOI: 10.7554/elife.08939] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 10/20/2015] [Indexed: 12/02/2022] Open
Abstract
Replication of influenza viral genomic RNA (vRNA) is catalyzed by viral RNA-dependent RNA polymerase (vRdRP). Complementary RNA (cRNA) is first copied from vRNA, and progeny vRNAs are then amplified from the cRNA. Although vRdRP and viral RNA are minimal requirements, efficient cell-free replication could not be reproduced using only these viral factors. Using a biochemical complementation assay system, we found a novel activity in the nuclear extracts of uninfected cells, designated IREF-2, that allows robust unprimed vRNA synthesis from a cRNA template. IREF-2 was shown to consist of host-derived proteins, pp32 and APRIL. IREF-2 interacts with a free form of vRdRP and preferentially upregulates vRNA synthesis rather than cRNA synthesis. Knockdown experiments indicated that IREF-2 is involved in in vivo viral replication. On the basis of these results and those of previous studies, a plausible role(s) for IREF-2 during the initiation processes of vRNA replication is discussed. DOI:http://dx.doi.org/10.7554/eLife.08939.001 The influenza or “flu” virus infects millions of people each year, with young children and elderly individuals most vulnerable to infection. The influenza virus stores its genetic material in the form of segments of single-stranded viral RNA. After the virus infects a cell, it replicates this genetic material in a two-part process. First, an enzyme made by the virus – called RNA polymerase – uses the viral genomic RNA as a template to form a “complementary” RNA strand (called cRNA). This cRNA molecule is then itself used as a template to make more viral genomic RNA strands, which can go on to form new viruses. Exactly how viral genomic RNA is made from cRNA is poorly understood, although previous research had suggested that this process may also involve proteins belonging to the invaded host cell. However, these host proteins had not been identified. By mixing virus particles with extracts from uninfected human cells, Sugiyama et al. have now found that two host proteins called pp32 and APRIL help viral genomic RNA to form from a cRNA template. Both of these proteins directly interact with the viral RNA polymerase. Sugiyama et al. then reduced the amounts of pp32 and APRIL in human cells that were infected with the influenza virus. Much less viral genomic RNA – and so fewer new virus particles – formed in these cells than in normal cells. Further work is now needed to understand how the pp32 and APRIL proteins interact with viral RNA polymerase. This could eventually lead to the development of new treatments for influenza. DOI:http://dx.doi.org/10.7554/eLife.08939.002
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Affiliation(s)
- Kenji Sugiyama
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Atsushi Kawaguchi
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Mitsuru Okuwaki
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
| | - Kyosuke Nagata
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba, Japan
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26
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Komatsu T, Dacheux D, Kreppel F, Nagata K, Wodrich H. A Method for Visualization of Incoming Adenovirus Chromatin Complexes in Fixed and Living Cells. PLoS One 2015; 10:e0137102. [PMID: 26332038 PMCID: PMC4557953 DOI: 10.1371/journal.pone.0137102] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022] Open
Abstract
Inside the adenovirus virion, the genome forms a chromatin-like structure with viral basic core proteins. Core protein VII is the major DNA binding protein and was shown to remain associated with viral genomes upon virus entry even after nuclear delivery. It has been suggested that protein VII plays a regulatory role in viral gene expression and is a functional component of viral chromatin complexes in host cells. As such, protein VII could be used as a maker to track adenoviral chromatin complexes in vivo. In this study, we characterize a new monoclonal antibody against protein VII that stains incoming viral chromatin complexes following nuclear import. Furthermore, we describe the development of a novel imaging system that uses Template Activating Factor-I (TAF-I/SET), a cellular chromatin protein tightly bound to protein VII upon infection. This setup allows us not only to rapidly visualize protein VII foci in fixed cells but also to monitor their movement in living cells. These powerful tools can provide novel insights into the spatio-temporal regulation of incoming adenoviral chromatin complexes.
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Affiliation(s)
- Tetsuro Komatsu
- Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, Université de Bordeaux, Bordeaux 33076, France
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba 305–8575, Japan
| | - Denis Dacheux
- Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, Université de Bordeaux, Bordeaux 33076, France
- Bordeaux INP, MCMP, UMR 5234, Bordeaux 33000, France
| | - Florian Kreppel
- Department of Gene Therapy, Ulm University, Ulm 89081, Germany
| | - Kyosuke Nagata
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, Tsukuba 305–8575, Japan
| | - Harald Wodrich
- Microbiologie Fondamentale et Pathogénicité, MFP CNRS UMR 5234, Université de Bordeaux, Bordeaux 33076, France
- * E-mail:
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Trakhtenberg EF, Morkin MI, Patel KH, Fernandez SG, Sang A, Shaw P, Liu X, Wang Y, Mlacker GM, Gao H, Velmeshev D, Dombrowski SM, Vitek MP, Goldberg JL. The N-terminal Set-β Protein Isoform Induces Neuronal Death. J Biol Chem 2015; 290:13417-26. [PMID: 25833944 DOI: 10.1074/jbc.m114.633883] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Indexed: 11/06/2022] Open
Abstract
Set-β protein plays different roles in neurons, but the diversity of Set-β neuronal isoforms and their functions have not been characterized. The expression and subcellular localization of Set-β are altered in Alzheimer disease, cleavage of Set-β leads to neuronal death after stroke, and the full-length Set-β regulates retinal ganglion cell (RGC) and hippocampal neuron axon growth and regeneration in a subcellular localization-dependent manner. Here we used various biochemical approaches to investigate Set-β isoforms and their role in the CNS, using the same type of neurons, RGCs, across studies. We found multiple alternatively spliced isoforms expressed from the Set locus in purified RGCs. Set transcripts containing the Set-β-specific exon were the most highly expressed isoforms. We also identified a novel, alternatively spliced Set-β transcript lacking the nuclear localization signal and demonstrated that the full-length (∼39-kDa) Set-β is localized predominantly in the nucleus, whereas a shorter (∼25-kDa) Set-β isoform is localized predominantly in the cytoplasm. Finally, we show that an N-terminal Set-β cleavage product can induce neuronal death.
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Affiliation(s)
- Ephraim F Trakhtenberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Melina I Morkin
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Karan H Patel
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | | | - Alan Sang
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Peter Shaw
- the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Xiongfei Liu
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Yan Wang
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093
| | - Gregory M Mlacker
- Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and
| | - Han Gao
- From the Neuroscience Program and
| | - Dmitry Velmeshev
- Molecular and Cellular Pharmacology Program,University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Susan M Dombrowski
- Genomatix Software, Ann Arbor, Michigan 48108, the Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, Michigan 48201
| | - Michael P Vitek
- Oncotide Pharmaceuticals Inc., Durham, North Carolina 27709, and the Department of Neurology, Duke University Medical Center, Durham, North Carolina 27708
| | - Jeffrey L Goldberg
- From the Neuroscience Program and Bascom Palmer Eye Institute and Interdisciplinary Stem Cell Institute, and the Shiley Eye Center, University of California San Diego, La Jolla, California 92093,
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28
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Expression of the histone chaperone SET/TAF-Iβ during the strobilation process of Mesocestoides corti (Platyhelminthes, Cestoda). Parasitology 2015; 142:1171-82. [DOI: 10.1017/s003118201500030x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
SUMMARYThe histone chaperone SET/TAF-Iβ is implicated in processes of chromatin remodelling and gene expression regulation. It has been associated with the control of developmental processes, but little is known about its function in helminth parasites. In Mesocestoides corti, a partial cDNA sequence related to SET/TAF-Iβ was isolated in a screening for genes differentially expressed in larvae (tetrathyridia) and adult worms. Here, the full-length coding sequence of the M. corti SET/TAF-Iβ gene was analysed and the encoded protein (McSET/TAF) was compared with orthologous sequences, showing that McSET/TAF can be regarded as a SET/TAF-Iβ family member, with a typical nucleosome-assembly protein (NAP) domain and an acidic tail. The expression patterns of the McSET/TAF gene and protein were investigated during the strobilation process by RT-qPCR, using a set of five reference genes, and by immunoblot and immunofluorescence, using monospecific polyclonal antibodies. A gradual increase in McSET/TAF transcripts and McSET/TAF protein was observed upon development induction by trypsin, demonstrating McSET/TAF differential expression during strobilation. These results provided the first evidence for the involvement of a protein from the NAP family of epigenetic effectors in the regulation of cestode development.
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Regulating Set-β's Subcellular Localization Toggles Its Function between Inhibiting and Promoting Axon Growth and Regeneration. J Neurosci 2014; 34:7361-74. [PMID: 24849368 DOI: 10.1523/jneurosci.3658-13.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The failure of the CNS neurons to regenerate axons after injury or stroke is a major clinical problem. Transcriptional regulators like Set-β are well positioned to regulate intrinsic axon regeneration capacity, which declines developmentally in maturing CNS neurons. Set-β also functions at cellular membranes and its subcellular localization is disrupted in Alzheimer's disease, but many of its biological mechanisms have not been explored in neurons. We found that Set-β was upregulated postnatally in CNS neurons, and was primarily localized to the nucleus but was also detected in the cytoplasm and adjacent to the plasma membrane. Remarkably, nuclear Set-β suppressed, whereas Set-β localized to cytoplasmic membranes promoted neurite growth in rodent retinal ganglion cells and hippocampal neurons. Mimicking serine 9 phosphorylation, as found in Alzheimer's disease brains, delayed nuclear import and furthermore blocked the ability of nuclear Set-β to suppress neurite growth. We also present data on gene regulation and protein binding partner recruitment by Set-β in primary neurons, raising the hypothesis that nuclear Set-β may preferentially regulate gene expression whereas Set-β at cytoplasmic membranes may regulate unique cofactors, including PP2A, which we show also regulates axon growth in vitro. Finally, increasing recruitment of Set-β to cellular membranes promoted adult rat optic nerve axon regeneration after injury in vivo. Thus, Set-β differentially regulates axon growth and regeneration depending on subcellular localization and phosphorylation.
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30
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Kim KB, Kim DW, Park JW, Jeon YJ, Kim D, Rhee S, Chae JI, Seo SB. Inhibition of Ku70 acetylation by INHAT subunit SET/TAF-Iβ regulates Ku70-mediated DNA damage response. Cell Mol Life Sci 2014; 71:2731-45. [PMID: 24305947 PMCID: PMC11113754 DOI: 10.1007/s00018-013-1525-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/28/2013] [Accepted: 11/14/2013] [Indexed: 11/30/2022]
Abstract
DNA double-strand breaks (DSBs) can cause either cell death or genomic instability. The Ku heterodimer Ku70/80 is required for the NHEJ (non-homologous end-joining) DNA DSB repair pathway. The INHAT (inhibitor of histone acetyltransferases) complex subunit, SET/TAF-Iβ, can inhibit p300- and PCAF-mediated acetylation of both histone and p53, thereby repressing general transcription and that of p53 target genes. Here, we show that SET/TAF-Iβ interacts with Ku70/80, and that this interaction inhibits CBP- and PCAF-mediated Ku70 acetylation in an INHAT domain-dependent manner. Notably, DNA damage by UV disrupted the interaction between SET/TAF-Iβ and Ku70. Furthermore, we demonstrate that overexpressed SET/TAF-Iβ inhibits recruitment of Ku70/80 to DNA damage sites. We propose that dysregulation of SET/TAF-Iβ expression prevents repair of damaged DNA and also contributes to cellular proliferation. All together, our findings indicate that SET/TAF-Iβ interacts with Ku70/80 in the nucleus and inhibits Ku70 acetylation. Upon DNA damage, SET/TAF-Iβ dissociates from the Ku complex and releases Ku70/Ku80, which are then recruited to DNA DSB sites via the NHEJ DNA repair pathway.
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Affiliation(s)
- Kee-Beom Kim
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, 156-756 Republic of Korea
| | - Dong-Wook Kim
- Department of Oral Pharmacology, School of Dentistry, Brain Korea 21 PLUS Project, Chonbuk National University, Jeonju, 561-756 Republic of Korea
- Present Address: Department of Microbiology, Immunology, and Cancer Biology, School of Medicine, University of Virginia, Charlottesville, VA USA
| | - Jin Woo Park
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, 156-756 Republic of Korea
| | - Young-Joo Jeon
- Department of Oral Pharmacology, School of Dentistry, Brain Korea 21 PLUS Project, Chonbuk National University, Jeonju, 561-756 Republic of Korea
| | - Daehwan Kim
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, 156-756 Republic of Korea
| | - Sangmyung Rhee
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, 156-756 Republic of Korea
| | - Jung-Il Chae
- Department of Oral Pharmacology, School of Dentistry, Brain Korea 21 PLUS Project, Chonbuk National University, Jeonju, 561-756 Republic of Korea
| | - Sang-Beom Seo
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul, 156-756 Republic of Korea
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Upregulation of SET expression by BACE1 and its implications in Down syndrome. Mol Neurobiol 2014; 51:781-90. [PMID: 24935721 DOI: 10.1007/s12035-014-8782-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/09/2014] [Indexed: 01/18/2023]
Abstract
Down syndrome (DS) is one of the most common genetic diseases. Patients with DS display growth delay and intellectual disabilities and develop Alzheimer's disease (AD) neuropathology after middle age, including neuritic plaques and neurofibrillary tangles. Beta-site amyloid β precursor protein (APP) cleaving enzyme 1 (BACE1), essential for Aβ production and neuritic plaque formation, is elevated in DS patients. However, its homolog, β-site APP cleaving enzyme 2 (BACE2), functions as θ-secretase and plays a differential role in plaque formation. In this study, by using Two-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (2D SDS-PAGE) and LC-MS/MS proteomic profiling analysis, we found that the SET oncogene protein (SET) expression was associated with BACE1 but not BACE2. SET protein was increased in BACE1 overexpressing cells and was markedly reduced in the BACE1 knockout mice. We found that the overexpression of BACE1 or SET significantly inhibited cell proliferation. Moreover, knockdown of SET in BACE1 overexpression cells significantly rescued BACE1-induced cell growth suppression. Furthermore, both BACE1 and SET protein levels were increased in Down syndrome patients. It suggests that BACE1 overexpression-induced SET upregulation may contribute to growth delay and cognitive impairment in DS patients. Our work provides a new insight that BACE1 overexpression not only promotes neuritic plaque formation but may also potentiate neurodegeneration mediated by SET elevation in Alzheimer-associated dementia in DS.
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Kadota S, Nagata K. Silencing of IFN-stimulated gene transcription is regulated by histone H1 and its chaperone TAF-I. Nucleic Acids Res 2014; 42:7642-53. [PMID: 24878923 PMCID: PMC4081089 DOI: 10.1093/nar/gku485] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Chromatin structure and its alteration play critical roles in the regulation of transcription. However, the transcriptional silencing mechanism with regard to the chromatin structure at an unstimulated state of the interferon (IFN)-stimulated gene (ISG) remains unclear. Here we investigated the role of template activating factor-I (TAF-I, also known as SET) in ISG transcription. Knockdown (KD) of TAF-I increased ISG transcript and simultaneously reduced the histone H1 level on the ISG promoters during the early stages of transcription after IFN stimulation from the unstimulated state. The transcription factor levels on the ISG promoters were increased in TAF-I KD cells only during the early stages of transcription. Furthermore, histone H1 KD also increased ISG transcript. TAF-I and histone H1 double KD did not show the additive effect in ISG transcription, suggesting that TAF-I and histone H1 may act on the same regulatory pathway to control ISG transcription. In addition, TAF-I KD and histone H1 KD affected the chromatin structure near the ISG promoters. On the basis of these findings, we propose that TAF-I and its target histone H1 are key regulators of the chromatin structure at the ISG promoter to maintain the silent state of ISG transcription.
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Affiliation(s)
- Shinichi Kadota
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
| | - Kyosuke Nagata
- Department of Infection Biology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Japan
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Mukhopadhyay A, Tabanor K, Chaguturu R, Aldrich JV. Targeting inhibitor 2 of protein phosphatase 2A as a therapeutic strategy for prostate cancer treatment. Cancer Biol Ther 2013; 14:962-72. [PMID: 24025258 DOI: 10.4161/cbt.25943] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Inhibitor 2 of protein phosphatase 2A (I2PP2A), a biological inhibitor of the cellular serine/threonine protein phosphatase PP2A, is associated with numerous cellular processes that often lead to the formation and progression of cancer. In this study we hypothesized that targeting the inhibition of I2PP2A's multiple functions in prostate cancer cells might prevent cancer progression. We have investigated the effect of the small chain C6-ceramide, known to be a bioactive tumor suppressor lipid, on I2PP2A function, thereby affecting c-Myc signaling and histone acetylation in cells. Our data indicated that C6-ceramide treatment of prostate cancer cells induces cell death in PC-3, DU145, and LNCaP cells, but not normal prostate epithelial cells. C6-ceramide was able to disrupt the association between PP2A and I2PP2A. C6-ceramide inhibits I2PP2A's upregulation of c-Myc and downregulation of histone acetylation in prostate cancer cells. Our data indicated that targeting cancer related signaling pathways through I2PP2A using ceramide as an anti-I2PP2A agent could have beneficial effects as a therapeutic approach to prevent prostate cancer.
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34
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Gao LL, Liu XQ, Xu BQ, Jiang SW, Cui YG, Liu JY. SET/PP2A system regulates androgen production in ovarian follicles in vitro. Mol Cell Endocrinol 2013; 374:108-16. [PMID: 23628604 DOI: 10.1016/j.mce.2013.04.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Revised: 03/15/2013] [Accepted: 04/19/2013] [Indexed: 01/31/2023]
Abstract
SET has multiple cell functions including nucleosome assembly, histone binding, transcription control, and cell apoptosis. In ovaries SET is predominantly expressed in theca cells and oocytes. In our study, SET overexpression in theca cells stimulated testosterone production whereas SET knockdown decreased testosterone production. Moreover, SET negatively regulated PP2A activity. Treatment with PP2A inhibitor okadaic acid (OA) led to increased testosterone synthesis, while treatment with PP2A activators resulted in the decreased testosterone synthesis. Furthermore, PP2A knockdown confirmed the key role of PP2A in the testosterone synthesis, and OA was able to block the AdH1-SiRNA/SET-mediated inhibition of testosterone production. The central role of PP2A in SET-mediated regulation of testosterone production was confirmed by the finding that SET promoted the lyase activity of P450c17 and that PP2A inhibited its lyase activity. Taken together, these results reveal a specific, SET-initiated, PP2A-mediated, pathway that leads to the increased lyase activity of P450c17 and testosterone biosynthesis.
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Affiliation(s)
- Ling-Ling Gao
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China.
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Hunter CS, Malik RE, Witzmann FA, Rhodes SJ. LHX3 interacts with inhibitor of histone acetyltransferase complex subunits LANP and TAF-1β to modulate pituitary gene regulation. PLoS One 2013; 8:e68898. [PMID: 23861948 PMCID: PMC3701669 DOI: 10.1371/journal.pone.0068898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 06/07/2013] [Indexed: 01/19/2023] Open
Abstract
LIM-homeodomain 3 (LHX3) is a transcription factor required for mammalian pituitary gland and nervous system development. Human patients and animal models with LHX3 gene mutations present with severe pediatric syndromes that feature hormone deficiencies and symptoms associated with nervous system dysfunction. The carboxyl terminus of the LHX3 protein is required for pituitary gene regulation, but the mechanism by which this domain operates is unknown. In order to better understand LHX3-dependent pituitary hormone gene transcription, we used biochemical and mass spectrometry approaches to identify and characterize proteins that interact with the LHX3 carboxyl terminus. This approach identified the LANP/pp32 and TAF-1β/SET proteins, which are components of the inhibitor of histone acetyltransferase (INHAT) multi-subunit complex that serves as a multifunctional repressor to inhibit histone acetylation and modulate chromatin structure. The protein domains of LANP and TAF-1β that interact with LHX3 were mapped using biochemical techniques. Chromatin immunoprecipitation experiments demonstrated that LANP and TAF-1β are associated with LHX3 target genes in pituitary cells, and experimental alterations of LANP and TAF-1β levels affected LHX3-mediated pituitary gene regulation. Together, these data suggest that transcriptional regulation of pituitary genes by LHX3 involves regulated interactions with the INHAT complex.
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Affiliation(s)
- Chad S. Hunter
- Department of Biology, Indiana University-Purdue University Indianapolis, Indiana, United States of America
| | - Raleigh E. Malik
- Department of Biochemistry and Molecular Biology, Indiana School of Medicine, Indianapolis, Indiana, United States of America
| | - Frank A. Witzmann
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Simon J. Rhodes
- Department of Biology, Indiana University-Purdue University Indianapolis, Indiana, United States of America
- Department of Biochemistry and Molecular Biology, Indiana School of Medicine, Indianapolis, Indiana, United States of America
- Department of Cellular and Integrative Physiology, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
- * E-mail:
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Mansouri S, Wang S, Frappier L. A role for the nucleosome assembly proteins TAF-Iβ and NAP1 in the activation of BZLF1 expression and Epstein-Barr virus reactivation. PLoS One 2013; 8:e63802. [PMID: 23691099 PMCID: PMC3653829 DOI: 10.1371/journal.pone.0063802] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 04/06/2013] [Indexed: 12/15/2022] Open
Abstract
The reactivation of Epstein-Barr virus (EBV) from latent to lytic infection begins with the expression of the viral BZLF1 gene, leading to a subsequent cascade of viral gene expression and amplification of the EBV genome. Using RNA interference, we show that nucleosome assembly proteins NAP1 and TAF-I positively contribute to EBV reactivation in epithelial cells through the induction of BZLF1 expression. In addition, overexpression of NAP1 or the β isoform of TAF-I (TAF-Iβ) in AGS cells latently infected with EBV was sufficient to induce BZLF1 expression. Chromatin immunoprecipitation experiments performed in AGS-EBV cells showed that TAF-I associated with the BZLF1 promoter upon lytic induction and affected local histone modifications by increasing H3K4 dimethylation and H4K8 acetylation. MLL1, the host protein known to dimethylate H3K4, was found to associate with the BZLF1 promoter upon lytic induction in a TAF-I-dependent manner, and MLL1 depletion decreased BZLF1 expression, confirming its contribution to lytic reactivation. The results indicate that TAF-Iβ promotes BZLF1 expression and subsequent lytic infection by affecting chromatin at the BZLF1 promoter.
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Affiliation(s)
- Sheila Mansouri
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Shan Wang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Lori Frappier
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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The PP2A inhibitor I2PP2A is essential for sister chromatid segregation in oocyte meiosis II. Curr Biol 2013; 23:485-90. [PMID: 23434280 DOI: 10.1016/j.cub.2013.02.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/02/2013] [Accepted: 02/01/2013] [Indexed: 11/20/2022]
Abstract
Haploid gametes are generated through two consecutive meiotic divisions, with the segregation of chromosome pairs in meiosis I and sister chromatids in meiosis II. Separase-mediated stepwise removal of cohesion, first from chromosome arms and later from the centromere region, is a prerequisite for maintaining sister chromatids together until their separation in meiosis II [1]. In all model organisms, centromeric cohesin is protected from separase-dependent removal in meiosis I through the activity of PP2A-B56 phosphatase, which is recruited to centromeres by shugoshin/MEI-S332 (Sgo) [2-5]. How this protection of centromeric cohesin is removed in meiosis II is not entirely clear; we find that all the PP2A subunits remain colocalized with the cohesin subunit Rec8 at the centromere of metaphase II chromosomes. Here, we show that sister chromatid separation in oocytes depends on a PP2A inhibitor, namely I2PP2A. I2PP2A colocalizes with the PP2A enzyme at centromeres at metaphase II, independently of bipolar attachment. When I2PP2A is depleted, sister chromatids fail to segregate during meiosis II. Our findings demonstrate that in oocytes I2PP2A is essential for faithful sister chromatid segregation by mediating deprotection of centromeric cohesin in meiosis II.
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Xu B, Gao L, Cui Y, Gao L, Dai X, Li M, Zhang Y, Ma X, Diao F, Liu J. SET protein up-regulated testosterone production in the cultured preantral follicles. Reprod Biol Endocrinol 2013; 11:9. [PMID: 23421880 PMCID: PMC3583798 DOI: 10.1186/1477-7827-11-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We found previously that the expression of SET gene was up-regulated in polycystic ovaries. Evidences suggested that SET protein was essential for regulating both the promoter activity of CYP17A1 and the biological activity of P450c17. In this study, we explored whether SET regulated androgen production in preantral follicles. METHODS The mouse preantral follicles were cultured in vitro. Testosterone secretion and expression of steroidogenic enzymes were observed in the preantral follicles treated in vitro by SET overexpression and knockdown. RESULTS Testosterone levels in the media of the AdCMV-SET infected follicles significantly increased, and the CYP17A1 and HSD3B2 expression also significantly increased (P < 0.05). Testosterone levels in AdSiRNA-SET infected group decreased, and so did CYP17A1 and HSD3B2 expression (P < 0.05). CONCLUSIONS SET played a positive role in regulating ovarian androgen biosynthesis by enhancing the transcription of steroidogenic enzymes CYP17A1 and HSD3B2, which maybe contribute to the hyperandrogenism in PCOS.
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Affiliation(s)
- Boqun Xu
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China
| | - Lingling Gao
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Yugui Cui
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Li Gao
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Xue Dai
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Nanjing Medical University, Nanjing, 210011, China
| | - Mei Li
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Yuan Zhang
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Xiang Ma
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Feiyang Diao
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
| | - Jiayin Liu
- The State Key Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing, 210029, China
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Lam BD, Hordijk PL. The Rac1 hypervariable region in targeting and signaling: a tail of many stories. Small GTPases 2013; 4:78-89. [PMID: 23354415 DOI: 10.4161/sgtp.23310] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cellular signaling by small GTPases is critically dependent on proper spatio-temporal orchestration of activation and output. In addition to their core G (guanine nucleotide binding)-domain, small GTPases comprise a hypervariable region (HVR) and a lipid anchor that are generally accepted to control subcellullar localization. The HVR encodes in many small GTPases a polybasic region (PBR) that permits charge-mediated association to the inner leaflet of the plasma membrane or to intracellular organelles. Over the past 15-20 years, evidence has accumulated for specific protein-protein interactions, mediated by the HVR, that control both targeting and signaling specificity of small GTPases. Using the RhoGTPase Rac1 as a paradigm we here review a series of protein partners that require the Rac1 HVR for association and that control various aspects of localized Rac1 signaling. Some of these proteins represent Rac1 activators, whereas others mediate Rac1 inactivation and degradation and yet others potentiate Rac1 downstream signaling. Finally, evidence is discussed which shows that the HVR of Rac1 also contributes to effector interactions, co-operating with the N-terminal effector domain. The complexity of localized Rac1 signaling, reviewed here, is most likely exemplary for many other small GTPases as well, representing a challenge to identify and define similar mechanisms controlling the specific signaling induced by small GTPases.
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Affiliation(s)
- B Daniel Lam
- Department of Molecular Cell Biology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, Swammerdam Institute of Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
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Boqun X, Xiaonan D, YuGui C, Lingling G, Xue D, Gao C, Feiyang D, Jiayin L, Gao L, Li M, Zhang Y, Ma X. Expression of SET Protein in the Ovaries of Patients with Polycystic Ovary Syndrome. Int J Endocrinol 2013; 2013:367956. [PMID: 23861679 PMCID: PMC3686144 DOI: 10.1155/2013/367956] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/23/2013] [Accepted: 05/09/2013] [Indexed: 11/30/2022] Open
Abstract
Background. We previously found that expression of SET gene was up-regulated in polycystic ovaries by using microarray. It suggested that SET may be an attractive candidate regulator involved in the pathophysiology of polycystic ovary syndrome (PCOS). In this study, expression and cellular localization of SET protein were investigated in human polycystic and normal ovaries. Method. Ovarian tissues, six normal ovaries and six polycystic ovaries, were collected during transsexual operation and surgical treatment with the signed consent form. The cellular localization of SET protein was observed by immunohistochemistry. The expression levels of SET protein were analyzed by Western Blot. Result. SET protein was expressed predominantly in the theca cells and oocytes of human ovarian follicles in both PCOS ovarian tissues and normal ovarian tissues. The level of SET protein expression in polycystic ovaries was triple higher than that in normal ovaries (P < 0.05). Conclusion. SET was overexpressed in polycystic ovaries more than that in normal ovaries. Combined with its localization in theca cells, SET may participate in regulating ovarian androgen biosynthesis and the pathophysiology of hyperandrogenism in PCOS.
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Affiliation(s)
- Xu Boqun
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
- Department of Obstetrics and Gynecology, Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China
| | - Dai Xiaonan
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Cui YuGui
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
- *Cui YuGui: and
| | - Gao Lingling
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Dai Xue
- Department of Obstetrics and Gynecology, Second Affiliated Hospital of Nanjing Medical University, Nanjing 210011, China
| | - Chao Gao
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Diao Feiyang
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
| | - Liu Jiayin
- The State Laboratory of Reproductive Medicine, Clinical Center of Reproductive Medicine, First Affiliated Hospital, Nanjing Medical University, Nanjing 210029, China
- *Liu Jiayin:
| | - Li Gao
- The First Affiliated Hospital, Nanjing Medical University, China
| | - Mei Li
- The First Affiliated Hospital, Nanjing Medical University, China
| | - Yuan Zhang
- The First Affiliated Hospital, Nanjing Medical University, China
| | - Xiang Ma
- The First Affiliated Hospital, Nanjing Medical University, China
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Hong WX, Yang L, Chen M, Yang X, Ren X, Fang S, Ye J, Huang H, Peng C, Zhou L, Huang X, Yang F, Wu D, Zhuang Z, Liu J. Proteomic analysis of trichloroethylene-induced alterations in expression, distribution, and interactions of SET/TAF-Iα and two SET/TAF-Iα-binding proteins, eEF1A1 and eEF1A2, in hepatic L-02 cells. Toxicol Appl Pharmacol 2012; 263:259-72. [DOI: 10.1016/j.taap.2012.06.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 06/24/2012] [Accepted: 06/25/2012] [Indexed: 12/01/2022]
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Fanis P, Gillemans N, Aghajanirefah A, Pourfarzad F, Demmers J, Esteghamat F, Vadlamudi RK, Grosveld F, Philipsen S, van Dijk TB. Five friends of methylated chromatin target of protein-arginine-methyltransferase[prmt]-1 (chtop), a complex linking arginine methylation to desumoylation. Mol Cell Proteomics 2012; 11:1263-73. [PMID: 22872859 DOI: 10.1074/mcp.m112.017194] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chromatin target of Prmt1 (Chtop) is a vertebrate-specific chromatin-bound protein that plays an important role in transcriptional regulation. As its mechanism of action remains unclear, we identified Chtop-interacting proteins using a biotinylation-proteomics approach. Here we describe the identification and initial characterization of Five Friends of Methylated Chtop (5FMC). 5FMC is a nuclear complex that can only be recruited by Chtop when the latter is arginine-methylated by Prmt1. It consists of the co-activator Pelp1, the Sumo-specific protease Senp3, Wdr18, Tex10, and Las1L. Pelp1 functions as the core of 5FMC, as the other components become unstable in the absence of Pelp1. We show that recruitment of 5FMC to Zbp-89, a zinc-finger transcription factor, affects its sumoylation status and transactivation potential. Collectively, our data provide a mechanistic link between arginine methylation and (de)sumoylation in the control of transcriptional activity.
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Affiliation(s)
- Pavlos Fanis
- Department of Cell Biology, Erasmus MC, 3000 CA, Rotterdam, The Netherlands
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Abstract
In infected cells, the chromatin structure of the adenovirus genome DNA plays critical roles in its genome functions. Previously, we reported that in early phases of infection, incoming viral DNA is associated with both viral core protein VII and cellular histones. Here we show that in late phases of infection, newly synthesized viral DNA is also associated with histones. We also found that the knockdown of CAF-1, a histone chaperone that functions in the replication-coupled deposition of histones, does not affect the level of histone H3 bound on viral chromatin, although CAF-1 is accumulated at viral DNA replication foci together with PCNA. Chromatin immunoprecipitation assays using epitope-tagged histone H3 demonstrated that histone variant H3.3, which is deposited onto the cellular genome in a replication-independent manner, is selectively associated with both incoming and newly synthesized viral DNAs. Microscopic analyses indicated that histones but not USF1, a transcription factor that regulates viral late gene expression, are excluded from viral DNA replication foci and that this is achieved by the oligomerization of the DNA binding protein (DBP). Taken together, these results suggest that histone deposition onto newly synthesized viral DNA is most likely uncoupled with viral DNA replication, and a possible role of DBP oligomerization in this replication-uncoupled histone deposition is discussed.
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Bíró J, Farkas I, Domoki M, Otvös K, Bottka S, Dombrádi V, Fehér A. The histone phosphatase inhibitory property of plant nucleosome assembly protein-related proteins (NRPs). PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2012; 52:162-168. [PMID: 22285370 DOI: 10.1016/j.plaphy.2011.12.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Accepted: 12/31/2011] [Indexed: 05/31/2023]
Abstract
SET/I(2)(PP2A), a member of the family of nucleosome assembly proteins (NAPs), has been previously described as a multifunctional protein inhibiting protein phosphatase 2A (PP2A)-mediated histone H3((pSer10)) dephosphorylation during the heat shock response in animal cells. In the present work we demonstrate that its plant orthologs, designated as NAP-related proteins (NRPs), have a similar in vitro biochemical activity and interact with PP2A and histone H3((pSer10))in vivo. Although heat shock gene promoters were found to be associated with histone H3((pSer10))-marked chromatin following a high temperature treatment, heat shock gene expression was not affected in NRP-deficient mutant Arabidopsis thaliana (L.) plantlets. These observations indicate that NRPs are potential regulators of histone dephosphorylation in plants, but they are dispensable for gene expression reorganization in response to heat shock.
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Affiliation(s)
- Judit Bíró
- Institute of Plant Biology, Biological Research Center, Hungarian Academy of Sciences, Temesvári krt. 62, H-6726 Szeged, Hungary
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Samad MA, Komatsu T, Okuwaki M, Nagata K. B23/nucleophosmin is involved in regulation of adenovirus chromatin structure at late infection stages, but not in virus replication and transcription. J Gen Virol 2012; 93:1328-1338. [PMID: 22337638 DOI: 10.1099/vir.0.036665-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
B23/nucleophosmin has been identified in vitro as a stimulatory factor for replication of adenovirus DNA complexed with viral basic core proteins. In the present study, the in vivo function of B23 in the adenovirus life cycle was studied. It was found that both the expression of a decoy mutant derived from adenovirus core protein V that tightly associates with B23 and small interfering RNA-mediated depletion of B23 impeded the production of progeny virions. However, B23 depletion did not significantly affect the replication and transcription of the virus genome. Chromatin immunoprecipitation analyses revealed that B23 depletion significantly increased the association of viral DNA with viral core proteins and cellular histones. These results suggest that B23 is involved in the regulation of association and/or dissociation of core proteins and cellular histones with the virus genome. In addition, these results suggest that proper viral chromatin assembly, regulated in part by B23, is crucial for the maturation of infectious virus particles.
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Affiliation(s)
- Mohammad Abdus Samad
- Department of Applied Nutrition and Food Technology, Faculty of Applied Science and Technology, Islamic University, Kushtia, Bangladesh.,Graduate School of Comprehensive Human Sciences and Faculty of Medicine, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba 305-8575, Japan
| | - Tetsuro Komatsu
- Graduate School of Comprehensive Human Sciences and Faculty of Medicine, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba 305-8575, Japan
| | - Mitsuru Okuwaki
- Initiatives for the Promotion of Young Scientists' Independent Research, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba 305-8577, Japan.,Graduate School of Comprehensive Human Sciences and Faculty of Medicine, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba 305-8575, Japan
| | - Kyosuke Nagata
- Graduate School of Comprehensive Human Sciences and Faculty of Medicine, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba 305-8575, Japan
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Daniel Lam B, Anthony EC, Hordijk PL. Analysis of nucleo-cytoplasmic shuttling of the proto-oncogene SET/I2PP2A. Cytometry A 2011; 81:81-9. [DOI: 10.1002/cyto.a.21153] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 07/26/2011] [Accepted: 09/16/2011] [Indexed: 02/03/2023]
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47
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Kim JY, Lee KS, Seol JE, Yu K, Chakravarti D, Seo SB. Inhibition of p53 acetylation by INHAT subunit SET/TAF-Iβ represses p53 activity. Nucleic Acids Res 2011; 40:75-87. [PMID: 21911363 PMCID: PMC3245910 DOI: 10.1093/nar/gkr614] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The tumor suppressor p53 responds to a wide variety of cellular stress signals. Among potential regulatory pathways, post-translational modifications such as acetylation by CBP/p300 and PCAF have been suggested for modulation of p53 activity. However, exactly how p53 acetylation is modulated remains poorly understood. Here, we found that SET/TAF-Iβ inhibited p300- and PCAF-mediated p53 acetylation in an INHAT (inhibitor of histone acetyltransferase) domain-dependent manner. SET/TAF-Iβ interacted with p53 and repressed transcription of p53 target genes. Consequently, SET/TAF-Iβ blocked both p53-mediated cell cycle arrest and apoptosis in response to cellular stress. Using different apoptosis analyses, including FACS, TUNEL and BrdU incorporation assays, we also found that SET/TAF-Iβ induced cellular proliferation via inhibition of p53 acetylation. Furthermore, we observed that apoptotic Drosophila eye phenotype induced by either dp53 overexpression or UV irradiation was rescued by expression of dSet. Inhibition of dp53 acetylation by dSet was observed in both cases. Our findings provide new insights into the regulation of stress-induced p53 activation by HAT-inhibiting histone chaperone SET/TAF-Iβ.
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Affiliation(s)
- Ji-Young Kim
- Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 156-756, Korea
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Shi HR, Fu ZQ, Deng H, Wang XM, Zhen HY, Chen Y, Liu LJ. Construction of eukaryotic vectors expressing shRNAs targeting the set gene. Shijie Huaren Xiaohua Zazhi 2011; 19:2521-2526. [DOI: 10.11569/wcjd.v19.i24.2521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To construct eukaryotic vectors expressing short hairpin RNAs (shRNAs) targeting the set gene which encodes an endogenous inhibitor of PP2A.
METHODS: Four oligonucleotides targeting the SET gene were synthesized and cloned into the eukaryotic expression plasmid pGPU6. The resulting four recombinant plasmids, pGPU6/GFP/Neo-SET-shRNA-1, 2, 3 and 4, were introduced into BGC-823 cells by lipofectamine-mediated transfection. The gene silencing efficiency was measured by Western blot
RESULTS: DNA sequencing and enzyme digestion analysis confirmed the identity of the four recombinant shRNA expression vectors. Immunofluorescsence demonstrated that transfection efficiency was above 80%. Transfection of pGPU6/GFP/Neo-SET-shRNA-3 significantly knocked down the expression of SET protein as revealed by Western blot. The silencing effect of pGPU6/GFP/Neo-SET-shRNA-3 on the expression of SET protein was most remarkable at 72 h after transfection.
CONCLUSION: Eukaryotic vectors expressing shRNAs targeting the set gene have been constructed successfully and can be used to study the role of SET in gastric cancer.
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Arnaud L, Chen S, Liu F, Li B, Khatoon S, Grundke-Iqbal I, Iqbal K. Mechanism of inhibition of PP2A activity and abnormal hyperphosphorylation of tau by I2(PP2A)/SET. FEBS Lett 2011; 585:2653-9. [PMID: 21806989 DOI: 10.1016/j.febslet.2011.07.020] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 06/30/2011] [Accepted: 07/12/2011] [Indexed: 11/30/2022]
Abstract
Protein phosphatase-2A (PP2A) activity, which is compromised in Alzheimer disease brain, is regulated by two endogenous inhibitors, one of them being I(2)(PP2A), a 277 amino acid long protein also known as SET. Here we report that both the amino terminal fragment (I(2NTF); aa 1-175) and the carboxy terminal fragment (I(2CTF); aa 176-277) of I(2)(PP2A) inhibit PP2A by binding to its catalytic subunit PP2Ac and cause hyperphosphorylation of tau. The C-terminal acidic region in I(2CTF) and Val 92 in I(2NTF) are essential for their association with PP2Ac and inhibition of the phosphatase activity.
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Affiliation(s)
- Lisette Arnaud
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, NY 10314, USA
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Komatsu T, Haruki H, Nagata K. Cellular and viral chromatin proteins are positive factors in the regulation of adenovirus gene expression. Nucleic Acids Res 2010; 39:889-901. [PMID: 20926393 PMCID: PMC3035442 DOI: 10.1093/nar/gkq783] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The adenovirus genome forms chromatin-like structure with viral core proteins. This complex supports only a low level of transcription in a cell-free system, and thus core proteins have been thought to be negative factors for transcription. The mechanism how the transcription from the viral DNA complexed with core proteins is activated in infected cells remains unclear. Here, we found that both core proteins and histones are bound with the viral DNA in early phases of infection. We also found that acetylation of histone H3 occurs at the promoter regions of viral active genes in a transcription-independent manner. In addition, when a plasmid DNA complexed with core proteins was introduced into cells, core proteins enhanced transcription. Knockdown of TAF-I, a remodeling factor for viral core protein-DNA complexes, reduces the enhancement effect by core proteins, indicating that core proteins positively regulate viral transcription through the interaction with TAF-I. We would propose a possible mechanism that core proteins ensure transcription by regulating viral chromatin structure through the interaction with TAF-I.
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Affiliation(s)
- Tetsuro Komatsu
- Department of Infection Biology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
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