1
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Xie Q, Tong C, Xiong X. An overview of the co-transcription factor NACC1: Beyond its pro-tumor effects. Life Sci 2024; 336:122314. [PMID: 38030057 DOI: 10.1016/j.lfs.2023.122314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 11/20/2023] [Accepted: 11/26/2023] [Indexed: 12/01/2023]
Abstract
Nucleus accumbens-associated protein 1 (NACC1) is a member of the broad complex, tramtrack, bric-a-brac/poxvirus and zinc finger (BTB/POZ) protein families, mainly exerting its biological functions as a transcription co-regulator. NACC1 forms homo- or hetero-dimers through the BTB/POZ or BANP, E5R, and NACC1 (BEN) domain with other transcriptional regulators to regulate downstream signals. Recently, the overexpression of NACC1 has been observed in various tumors and is positively associated with tumor progression, high recurrence rate, indicating poor prognosis. NACC1 also regulates biological processes such as embryonic development, stem cell pluripotency, innate immunity, and related diseases. Our review combines recent research to summarize advancements in the structure, biological functions, and relative molecular mechanisms of NACC1. The future development of NACC1 clinical appliances is also discussed.
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Affiliation(s)
- Qing Xie
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China; School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China
| | - Chang Tong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China
| | - Xiangyang Xiong
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Nanchang University, Nanchang, 330006, China; Province Key Laboratory of Tumor Pathogens and Molecular Pathology, Nanchang University, Nanchang 330006, China.
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2
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Liu K, Zhang J, Xiao Y, Yang A, Song X, Li Y, Chen Y, Hughes TR, Min J. Structural insights into DNA recognition by the BEN domain of the transcription factor BANP. J Biol Chem 2023; 299:104734. [PMID: 37086783 DOI: 10.1016/j.jbc.2023.104734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 04/12/2023] [Accepted: 04/15/2023] [Indexed: 04/24/2023] Open
Abstract
The BEN domain-containing transcription factors regulate transcription by recruiting chromatin-modifying factors to specific chromatin regions via their DNA-binding BEN domains. The BEN domain of BANP has been shown to bind to a CGCG DNA sequence or an AAA-containing MARs (matrix attachment regions) DNA sequence. Consistent with these in vivo observations, we identified an optimal DNA binding sequence of AAATCTCG by PBM (protein binding microarray), which was also confirmed by our ITC (Isothermal Titration Calorimetry) and mutagenesis results to uncover additional mechanistic details about DNA binding by the BEN domain of BANP. We then determined crystal structures of the BANP BEN domain in apo form and in complex with a CGCG-containing DNA, respectively, which revealed that the BANP BEN domain mainly used the electrostatic interactions to bind DNA with some base-specific interactions with the TC motifs. Our ITC results also showed that BANP bound to unmethylated and methylated DNAs with comparable binding affinities. Our complex structure of BANP-mCGCG revealed that the BANP BEN domain bound to the unmethylated and methylated DNAs in a similar mode and cytosine methylation did not get involved in binding, which is also consistent with our observations from the complex structures of the BEND6 BEN domain with the CGCG or CGmCG DNAs. Taken together, our results further elucidate the elements important for DNA recognition and transcriptional regulation by the BANP BEN domain-containing transcription factor.
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Affiliation(s)
- Ke Liu
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China.
| | - Jin Zhang
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Yuqing Xiao
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Ally Yang
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1, Canada
| | - Xiaosheng Song
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Yanjun Li
- Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario M5S 3E1, Canada
| | - Yunxia Chen
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China
| | - Timothy R Hughes
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, M5S 3E1, Canada
| | - Jinrong Min
- Hubei Key Laboratory of Genetic Regulation and Integrative Biology, School of Life Sciences, Central China Normal University, Wuhan 430079, PR China; Structural Genomics Consortium and Department of Physiology, University of Toronto, Toronto, Ontario M5S 3E1, Canada.
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3
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Ma L, Xie D, Luo M, Lin X, Nie H, Chen J, Gao C, Duo S, Han C. Identification and characterization of BEND2 as a key regulator of meiosis during mouse spermatogenesis. SCIENCE ADVANCES 2022; 8:eabn1606. [PMID: 35613276 PMCID: PMC9132480 DOI: 10.1126/sciadv.abn1606] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/08/2022] [Indexed: 05/07/2023]
Abstract
The chromatin state, which undergoes global changes during spermatogenesis, is critical to meiotic initiation and progression. However, the key regulators involved and the underlying molecular mechanisms remain to be uncovered. Here, we report that mouse BEND2 is specifically expressed in spermatogenic cells around meiotic initiation and that it plays an essential role in meiotic progression. Bend2 gene knockout in male mice arrested meiosis at the transition from zygonema to pachynema, disrupted synapsis and DNA double-strand break repair, and induced nonhomologous chromosomal pairing. BEND2 interacted with chromatin-associated proteins that are components of certain transcription-repressor complexes. BEND2-binding sites were identified in diverse chromatin states and enriched in simple sequence repeats. BEND2 inhibited the expression of genes involved in meiotic initiation and regulated chromatin accessibility and the modification of H3K4me3. Therefore, our study identified BEND2 as a previously unknown key regulator of meiosis, gene expression, and chromatin state during mouse spermatogenesis.
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Affiliation(s)
- Longfei Ma
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dan Xie
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mengcheng Luo
- Department of Tissue and Embryology, Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei Province, China
| | - Xiwen Lin
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
| | - Hengyu Nie
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jian Chen
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
| | - Chenxu Gao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shuguang Duo
- Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Chunsheng Han
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China
- Savaid Medical School, University of Chinese Academy of Sciences, Beijing 100049, China
- Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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4
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BEND3 safeguards pluripotency by repressing differentiation-associated genes. Proc Natl Acad Sci U S A 2022; 119:2107406119. [PMID: 35217604 PMCID: PMC8892337 DOI: 10.1073/pnas.2107406119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2022] [Indexed: 12/17/2022] Open
Abstract
The molecular basis of how the BEN domain–containing gene family regulates chromatin function and transcription remains to be elucidated. We report that BEND3 is highly expressed in pluripotent cells and binds to promoters of genes involved in differentiation. BEND3 regulates the expression of differentiation-associated genes by modulating the chromatin architecture at promoters. We propose that transcription repression mediated by BEND3 is essential for normal development and maintenance of pluripotency. BEN domain–containing proteins are emerging rapidly as an important class of factors involved in modulating gene expression, yet the molecular basis of how they regulate chromatin function and transcription remains to be established. BEND3 is a quadruple BEN domain–containing protein that associates with heterochromatin and functions as a transcriptional repressor. We find that BEND3 is highly expressed in pluripotent cells, and the induction of differentiation results in the down-regulation of BEND3. The removal of BEND3 from pluripotent cells results in cells exhibiting upregulation of the differentiation-inducing gene expression signature. We find that BEND3 binds to the promoters of differentiation-associated factors and key cell cycle regulators, including CDKN1A, encoding the cell cycle inhibitor p21, and represses the expression of differentiation-associated genes by enhancing H3K27me3 decoration at these promoters. Our results support a model in which transcription repression mediated by BEND3 is essential for normal development and to prevent differentiation.
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5
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Zheng L, Liu J, Niu L, Kamran M, Yang AWH, Jolma A, Dai Q, Hughes TR, Patel DJ, Zhang L, Prasanth SG, Yu Y, Ren A, Lai EC. Distinct structural bases for sequence-specific DNA binding by mammalian BEN domain proteins. Genes Dev 2022; 36:225-240. [PMID: 35144965 PMCID: PMC8887127 DOI: 10.1101/gad.348993.121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Accepted: 01/05/2022] [Indexed: 11/24/2022]
Abstract
The BEN domain is a recently recognized DNA binding module that is present in diverse metazoans and certain viruses. Several BEN domain factors are known as transcriptional repressors, but, overall, relatively little is known of how BEN factors identify their targets in humans. In particular, X-ray structures of BEN domain:DNA complexes are only known for Drosophila factors bearing a single BEN domain, which lack direct vertebrate orthologs. Here, we characterize several mammalian BEN domain (BD) factors, including from two NACC family BTB-BEN proteins and from BEND3, which has four BDs. In vitro selection data revealed sequence-specific binding activities of isolated BEN domains from all of these factors. We conducted detailed functional, genomic, and structural studies of BEND3. We show that BD4 is a major determinant for in vivo association and repression of endogenous BEND3 targets. We obtained a high-resolution structure of BEND3-BD4 bound to its preferred binding site, which reveals how BEND3 identifies cognate DNA targets and shows differences with one of its non-DNA-binding BEN domains (BD1). Finally, comparison with our previous invertebrate BEN structures, along with additional structural predictions using AlphaFold2 and RoseTTAFold, reveal distinct strategies for target DNA recognition by different types of BEN domain proteins. Together, these studies expand the DNA recognition activities of BEN factors and provide structural insights into sequence-specific DNA binding by mammalian BEN proteins.
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Affiliation(s)
- Luqian Zheng
- The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen, Guangdong 518033, China
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jingjing Liu
- State Key Laboratory of Medical Molecular Biology, Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Lijie Niu
- State Key Laboratory of Medical Molecular Biology, Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
| | - Mohammad Kamran
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Ally W H Yang
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
- Donnelly Centre, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Arttu Jolma
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
- Donnelly Centre, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Qi Dai
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Timothy R Hughes
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A1, Canada
- Donnelly Centre, University of Toronto, Toronto, Ontario M5S 1A1, Canada
| | - Dinshaw J Patel
- Structural Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Long Zhang
- The Eighth Affiliated Hospital, Sun Yat-Sen University, Shenzhen, Guangdong 518033, China
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Supriya G Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Yang Yu
- State Key Laboratory of Medical Molecular Biology, Department of Molecular Biology and Biochemistry, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing 100005, China
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
| | - Aiming Ren
- Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Eric C Lai
- Developmental Biology Program, Sloan Kettering Institute, New York, New York 10065, USA
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6
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Nucleus Accumbens-Associated Protein 1 Binds DNA Directly through the BEN Domain in a Sequence-Specific Manner. Biomedicines 2020; 8:biomedicines8120608. [PMID: 33327466 PMCID: PMC7764960 DOI: 10.3390/biomedicines8120608] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/10/2020] [Accepted: 12/10/2020] [Indexed: 01/03/2023] Open
Abstract
Nucleus accumbens-associated protein 1 (NAC1) is a nuclear protein that harbors an amino-terminal BTB domain and a carboxyl-terminal BEN domain. NAC1 appears to play significant and diverse functions in cancer and stem cell biology. Here we demonstrated that the BEN domain of NAC1 is a sequence-specific DNA-binding domain. We selected the palindromic 6 bp motif ACATGT as a target sequence by using a PCR-assisted random oligonucleotide selection approach. The interaction between NAC1 and target DNA was characterized by gel shift assays, pull-down assays, isothermal titration calorimetry (ITC), chromatin-immunoprecipitation assays, and NMR chemical shifts perturbation (CSP). The solution NMR structure revealed that the BEN domain of human NAC-1 is composed of five conserved α helices and two short β sheets, with an additional hitherto unknown N-terminal α helix. In particular, ITC clarified that there are two sequential events in the titration of the BEN domain of NAC1 into the target DNA. The ITC results were further supported by CSP data and structure analyses. Furthermore, live cell photobleaching analyses revealed that the BEN domain of NAC1 alone was unable to interact with chromatin/other proteins in cells.
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7
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Ueberschär M, Wang H, Zhang C, Kondo S, Aoki T, Schedl P, Lai EC, Wen J, Dai Q. BEN-solo factors partition active chromatin to ensure proper gene activation in Drosophila. Nat Commun 2019; 10:5700. [PMID: 31836703 PMCID: PMC6911014 DOI: 10.1038/s41467-019-13558-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 11/14/2019] [Indexed: 11/08/2022] Open
Abstract
The Drosophila genome encodes three BEN-solo proteins including Insensitive (Insv), Elba1 and Elba2 that possess activities in transcriptional repression and chromatin insulation. A fourth protein-Elba3-bridges Elba1 and Elba2 to form an ELBA complex. Here, we report comprehensive investigation of these proteins in Drosophila embryos. We assess common and distinct binding sites for Insv and ELBA and their genetic interdependencies. While Elba1 and Elba2 binding generally requires the ELBA complex, Elba3 can associate with chromatin independently of Elba1 and Elba2. We further demonstrate that ELBA collaborates with other insulators to regulate developmental patterning. Finally, we find that adjacent gene pairs separated by an ELBA bound sequence become less differentially expressed in ELBA mutants. Transgenic reporters confirm the insulating activity of ELBA- and Insv-bound sites. These findings define ELBA and Insv as general insulator proteins in Drosophila and demonstrate the functional importance of insulators to partition transcription units.
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Affiliation(s)
- Malin Ueberschär
- Department of Molecular Bioscience, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Huazhen Wang
- Department of Molecular Bioscience, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Chun Zhang
- Department of Molecular Bioscience, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- State Key Laboratory of Developmental Biology of Freshwater Fish College of Life Sciences, Hunan Normal University, Changsha, China
| | - Shu Kondo
- Laboratory of Invertebrate Genetics, National Institute of Genetics, Mishima, Japan
| | - Tsutomu Aoki
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Paul Schedl
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Eric C Lai
- Department of Developmental Biology, Memorial Sloan Kettering Institute, New York, NY, USA.
| | - Jiayu Wen
- Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
| | - Qi Dai
- Department of Molecular Bioscience, the Wenner-Gren Institute, Stockholm University, Stockholm, Sweden.
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8
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Choi H, Park HJ, Kim H, Kim J, Lee YK, Kim J. Nac1 facilitates pluripotency gene activation for establishing somatic cell reprogramming. Biochem Biophys Res Commun 2019; 518:253-258. [PMID: 31412978 DOI: 10.1016/j.bbrc.2019.08.043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 08/08/2019] [Indexed: 01/07/2023]
Abstract
Transcription factors play a central role in pluripotency transcription circuitry for establishing pluripotent reprogramming. Master transcription factors Oct4, Nanog, and Sox2 are known to form the core of the pluripotency transcription network. Other transcription factors also play critical roles for further refining the core circuitry for pluripotency in induced pluripotent stem (iPS) cells. Here, we reported that Nac1 interacted with the master pluripotent factors Oct4 and Nanog co-occupies gene promoters bound by these transcriptional factors for establishing pluripotency. Moreover, this interaction coordinates gene expression with H3K4me3 in the somatic cell reprogramming. Knockdown of Nac1 suppressed somatic cell reprogramming, whereas overexpression of Nac1 resulted in enhanced efficiency of induced pluripotent cell generation. Altogether, these results reveal the genome wide role for Nac1 in the contribution to the pluripotency circuitry and the regulation of the establishing pluripotent state.
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Affiliation(s)
- Hwan Choi
- Laboratory of Stem Cells & Cell reprogramming, Department of Biomedical Engineering, Dongguk University, Seoul, 100-715, Republic of Korea
| | - Hyeok Ju Park
- Database Laboratory, Department of Computer Science and Engineering, Dongguk University, Pildong-ro 1-gil 30, Jung-gu, Seoul, 04620, Republic of Korea
| | - Hongwon Kim
- Laboratory of Stem Cells & Cell reprogramming, Department of Biomedical Engineering, Dongguk University, Seoul, 100-715, Republic of Korea
| | - Junyeop Kim
- Laboratory of Stem Cells & Cell reprogramming, Department of Biomedical Engineering, Dongguk University, Seoul, 100-715, Republic of Korea
| | - Yong Kyu Lee
- Database Laboratory, Department of Computer Science and Engineering, Dongguk University, Pildong-ro 1-gil 30, Jung-gu, Seoul, 04620, Republic of Korea
| | - Jongpil Kim
- Laboratory of Stem Cells & Cell reprogramming, Department of Biomedical Engineering, Dongguk University, Seoul, 100-715, Republic of Korea; Department of Chemistry, Dongguk University, Seoul, 100-715, Republic of Korea.
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9
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Targeting oncogenic transcriptional corepressor Nac1 POZ domain with conformationally constrained peptides by cyclization and stapling. Bioorg Chem 2018; 80:1-10. [DOI: 10.1016/j.bioorg.2018.05.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 05/10/2018] [Accepted: 05/23/2018] [Indexed: 12/13/2022]
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10
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Nakayama N, Sakashita G, Nariai Y, Kato H, Sinmyozu K, Nakayama JI, Kyo S, Urano T, Nakayama K. Cancer-related transcription regulator protein NAC1 forms a protein complex with CARM1 for ovarian cancer progression. Oncotarget 2018; 9:28408-28420. [PMID: 29983869 PMCID: PMC6033357 DOI: 10.18632/oncotarget.25400] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 04/16/2018] [Indexed: 01/07/2023] Open
Abstract
NAC1 is a cancer-related transcription regulator protein that is overexpressed in various carcinomas, including ovarian, cervical, breast, and pancreatic carcinomas. NAC1 knock-down was previously shown to result in the apoptosis of ovarian cancer cell lines and to rescue their sensitivity to chemotherapy, suggesting that NAC1 may be a potential therapeutic target, but protein complex formation of intranuclear NAC1 in ovarian cancer cells remain poorly understood. In this study, analysis of ovarian cancer cell lysates by fast protein liquid chromatography on a sizing column showed that the NAC1 peak corresponded to an apparent molecular mass of 300–500 kDa, which is larger than the estimated molecular mass (58 kDa) of the protein. Liquid chromatography-tandem mass spectrometry analysis identified CARM1 as interacting with NAC1 in the protein complex. Furthermore, tissue microarray analysis revealed a significant correlation between CARM1 and NAC1 expression levels. Ovarian cancer patients expressing high levels of NAC1 and CARM1 exhibited poor prognosis after adjuvant chemotherapy. Collectively, our results demonstrate that high expression levels of NAC1 and its novel binding partner CARM1 may serve as an informative prognostic biomarker for predicting resistance to chemotherapy for ovarian cancer.
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Affiliation(s)
- Naomi Nakayama
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Gyosuke Sakashita
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Yuko Nariai
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Kaori Sinmyozu
- Proteomics Support Unit, RIKEN Center for Developmental Biology, Kobe, Japan.,Current address: National Cerebral and Cardiovascular Center, Osaka, Japan
| | - Jun-Ichi Nakayama
- Graduate School of Natural Sciences, Nagoya City University, Nagoya, Japan
| | - Satoru Kyo
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo, Japan
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan
| | - Kentaro Nakayama
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo, Japan
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11
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Ruan Y, He J, Wu W, He P, Tian Y, Xiao L, Liu G, Wang J, Cheng Y, Zhang S, Yang Y, Xiong J, Zhao K, Wan Y, Huang H, Zhang J, Jian R. Nac1 promotes self-renewal of embryonic stem cells through direct transcriptional regulation of c-Myc. Oncotarget 2018; 8:47607-47618. [PMID: 28548937 PMCID: PMC5564591 DOI: 10.18632/oncotarget.17744] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 04/27/2017] [Indexed: 01/11/2023] Open
Abstract
The pluripotency transcriptional network in embryonic stem cells (ESCs) is composed of distinct functional units including the core and Myc units. It is hoped that dissection of the cellular functions and interconnections of network factors will aid our understanding of ESC and cancer biology. Proteomic and genomic approaches have identified Nac1 as a member of the core pluripotency network. However, previous studies have predominantly focused on the role of Nac1 in psychomotor stimulant response and cancer pathogenesis. In this study, we report that Nac1 is a self-renewal promoting factor, but is not required for maintaining pluripotency of ESCs. Loss of function of Nac1 in ESCs results in a reduced proliferation rate and an enhanced differentiation propensity. Nac1 overexpression promotes ESC proliferation and delays ESC differentiation in the absence of leukemia inhibitory factor (LIF). Furthermore, we demonstrated that Nac1 directly binds to the c-Myc promoter and regulates c-Myc transcription. The study also revealed that the function of Nac1 in promoting ESC self-renewal appears to be partially mediated by c-Myc. These findings establish a functional link between the core and c-Myc-centered networks and provide new insights into mechanisms of stemness regulation in ESCs and cancer.
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Affiliation(s)
- Yan Ruan
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China.,Biomedical Analysis Center, Third Military Medical University, Chongqing 400038, China
| | - Jianrong He
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China.,Department of Anesthesiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Wei Wu
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Ping He
- Department of Cardiothoracic Surgery, Southwest Hospital, Third Military Medical University, Chongqing 400038, China
| | - Yanping Tian
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Lan Xiao
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Gaoke Liu
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Jiali Wang
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Yuda Cheng
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Shuo Zhang
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Yi Yang
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Jiaxiang Xiong
- Experimental Center of Basic Medicine, College of Basic Medical Sciences, Third Military Medical University, Chongqing 400038, China
| | - Ke Zhao
- State Key Laboratory of Proteomics, Beijing Proteome Research Center, Beijing Institute of Radiation Medicine, Beijing 100850, China
| | - Ying Wan
- Biomedical Analysis Center, Third Military Medical University, Chongqing 400038, China
| | - He Huang
- Department of Anesthesiology, Xinqiao Hospital, Third Military Medical University, Chongqing 400037, China
| | - Junlei Zhang
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
| | - Rui Jian
- Laboratory of Stem Cell and Developmental Biology, Department of Histology and Embryology, Third Military Medical University, Chongqing 400038, China
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REST corepressors RCOR1 and RCOR2 and the repressor INSM1 regulate the proliferation-differentiation balance in the developing brain. Proc Natl Acad Sci U S A 2017; 114:E406-E415. [PMID: 28049845 DOI: 10.1073/pnas.1620230114] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The transcriptional events that lead to the cessation of neural proliferation, and therefore enable the production of proper numbers of differentiated neurons and glia, are still largely uncharacterized. Here, we report that the transcription factor Insulinoma-associated 1 (INSM1) forms complexes with RE1 Silencing Transcription factor (REST) corepressors RCOR1 and RCOR2 in progenitors in embryonic mouse brain. Mice lacking both RCOR1 and RCOR2 in developing brain die perinatally and generate an abnormally high number of neural progenitors at the expense of differentiated neurons and oligodendrocyte precursor cells. In addition, Rcor1/2 deletion detrimentally affects complex morphological processes such as closure of the interganglionic sulcus. We find that INSM1, a transcription factor that induces cell-cycle arrest, is coexpressed with RCOR1/2 in a subset of neural progenitors and forms complexes with RCOR1/2 in embryonic brain. Further, the Insm1-/- mouse phenocopies predominant brain phenotypes of the Rcor1/2 knockout. A large number of genes are concordantly misregulated in both knockout genotypes, and a majority of the down-regulated genes are targets of REST. Rest transcripts are up-regulated in both knockouts, and reducing transcripts to control levels in the Rcor1/2 knockout partially rescues the defect in interganglionic sulcus closure. Our findings indicate that an INSM1/RCOR1/2 complex controls the balance of proliferation and differentiation during brain development.
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Nakayama N, Kato H, Sakashita G, Nariai Y, Nakayama K, Kyo S, Urano T. Protein complex formation and intranuclear dynamics of NAC1 in cancer cells. Arch Biochem Biophys 2016; 606:10-5. [PMID: 27424155 DOI: 10.1016/j.abb.2016.07.007] [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: 06/02/2016] [Revised: 07/01/2016] [Accepted: 07/11/2016] [Indexed: 10/21/2022]
Abstract
Nucleus accumbens-associated protein 1 (NAC1) is a cancer-related transcription regulator protein that is also involved in the pluripotency and differentiation of embryonic stem cells. NAC1 is overexpressed in various carcinomas including ovarian, cervical, breast, and pancreatic carcinomas. NAC1 knock-down was previously shown to result in the apoptosis of ovarian cancer cell lines and to rescue their sensitivity to chemotherapy, suggesting that NAC1 may be a potential therapeutic target, but protein complex formation and the dynamics of intranuclear NAC1 in cancer cells remain poorly understood. In this study, analysis of HeLa cell lysates by fast protein liquid chromatography (FPLC) on a sizing column showed that the NAC1 peak corresponded to an apparent molecular mass of 300-500 kDa, which is larger than the estimated molecular mass (58 kDa) of the protein. Furthermore, live cell photobleaching analyses with green fluorescent protein (GFP)-fused NAC1 proteins revealed the intranuclear dynamics of NAC1. Collectively our results demonstrate that NAC1 forms a protein complex to function as a transcriptional regulator in cancer cells.
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Affiliation(s)
- Naomi Nakayama
- Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Gyosuke Sakashita
- Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Yuko Nariai
- Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Kentaro Nakayama
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Satoru Kyo
- Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan.
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14
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A Role for Nuclear Actin in HDAC 1 and 2 Regulation. Sci Rep 2016; 6:28460. [PMID: 27345839 PMCID: PMC4921920 DOI: 10.1038/srep28460] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 05/26/2016] [Indexed: 01/13/2023] Open
Abstract
Class I histone deacetylases (HDACs) are known to remove acetyl groups from histone tails. This liberates positive charges on the histone tail and allows for tighter winding of DNA, preventing transcription factor binding and gene activation. Although the functions of HDAC proteins are becoming apparent both biochemically and clinically, how this class of proteins is regulated remains poorly understood. We identified a novel interaction between nuclear actin and HDAC 1 and HDAC 2. Nuclear actin has been previously shown to interact with a growing list of nuclear proteins including chromatin remodeling complexes, transcription factors and RNA polymerases. We find that monomeric actin is able to bind the class I HDAC complex. Furthermore, increasing the concentration of actin in HeLa nuclear extracts was able to suppress overall HDAC function. Conversely, polymerizing nuclear actin increased HDAC activity and decreased histone acetylation. Moreover, the interaction between class I HDACs and nuclear actin was found to be activity dependent. Together, our data suggest nuclear actin is able to regulate HDAC 1 and 2 activity.
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15
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Abstract
Covalent linkage to members of the small ubiquitin-like (SUMO) family of proteins is an important mechanism by which the functions of many cellular proteins are regulated. Sumoylation has roles in the control of protein stability, activity and localization, and is involved in the regulation of transcription, gene expression, chromatin structure, nuclear transport and RNA metabolism. Sumoylation is also linked, both positively and negatively, with the replication of many different viruses both in terms of modification of viral proteins and modulation of sumoylated cellular proteins that influence the efficiency of infection. One prominent example of the latter is the widespread reduction in the levels of cellular sumoylated species induced by herpes simplex virus type 1 (HSV-1) ubiquitin ligase ICP0. This activity correlates with relief from intrinsic immunity antiviral defence mechanisms. Previous work has shown that ICP0 is selective in substrate choice, with some sumoylated proteins such the promyelocytic leukemia protein PML being extremely sensitive, while RanGAP is completely resistant. Here we present a comprehensive proteomic analysis of changes in the cellular SUMO2 proteome during HSV-1 infection. Amongst the 877 potentially sumoylated species detected, we identified 124 whose abundance was decreased by a factor of 3 or more by the virus, several of which were validated by western blot and expression analysis. We found many previously undescribed substrates of ICP0 whose degradation occurs by a range of mechanisms, influenced or not by sumoylation and/or the SUMO2 interaction motif within ICP0. Many of these proteins are known or are predicted to be involved in the regulation of transcription, chromatin assembly or modification. These results present novel insights into mechanisms and host cell proteins that might influence the efficiency of HSV-1 infection. Proteins are subject to many types of modification that regulate their functions and which are applied after their initial synthesis in the cell. One such modification is known as sumoylation, the covalent linkage of a small ubiquitin-like protein to a wide variety of substrate proteins. Sumoylation is involved in the regulation of many cellular pathways, including transcription, DNA repair, chromatin modification and defence to viral infections. Several viruses have connections with sumoylation, either through modification of their own proteins or in changing the sumoylation status of cellular proteins in ways that may be beneficial for infection. Herpes simplex virus type 1 (HSV-1) causes a widespread reduction in uncharacterized sumoylated cellular protein species, an effect that is caused by one of its key regulatory proteins (ICP0), which also induces the degradation of a number of repressive cellular proteins and thereby stimulates efficient infection. This study describes a comprehensive analysis of cellular proteins whose sumoylation status is altered by HSV-1 infection. Of 877 putative cellular sumoylation substrates, we found 124 whose sumoylation status reduces at least three-fold during infection. We validated the behavior of several such proteins and identified amongst them several novel targets of ICP0 activity with predicted repressive properties.
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BEND3 represses rDNA transcription by stabilizing a NoRC component via USP21 deubiquitinase. Proc Natl Acad Sci U S A 2015; 112:8338-43. [PMID: 26100909 DOI: 10.1073/pnas.1424705112] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Ribosome biogenesis dictates the translational capacity of cells. Several mechanisms establish and maintain transcriptional output from eukaryotic ribosomal DNA (rDNA) loci. rDNA silencing is one such mechanism that ensures the inactivity and hence the maintenance of a silenced state of a subset of rRNA gene copies. Whereas oncogenic agents stimulate rRNA gene transcription, tumor suppressors decrease rRNA gene transcription. We demonstrate in mammalian cells that BANP, E5R, and Nac1 (BEN) domain 3 (BEND3), a quadruple BEN domain-containing protein, localizes in nucleoli and binds to ribosomal RNA gene promoters to help repress rRNA genes. Loss of BEND3 increases histone H3K4 trimethylation and, correspondingly, decreases rDNA promoter DNA methylation, consistent with a role for BEND3 in rDNA silencing. BEND3 associates with the nucleolar-remodeling complex (NoRC), and SUMOylated BEND3 stabilizes NoRC component TTF-1-interacting protein 5 via association with ubiquitin specific protease 21 (USP21) debiquitinase. Our results provide mechanistic insights into how the novel rDNA transcription repressor BEND3 acts together with NoRC to actively coordinate the establishment of rDNA silencing.
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Dai Q, Ren A, Westholm JO, Duan H, Patel DJ, Lai EC. Common and distinct DNA-binding and regulatory activities of the BEN-solo transcription factor family. Genes Dev 2015; 29:48-62. [PMID: 25561495 PMCID: PMC4281564 DOI: 10.1101/gad.252122.114] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The BEN domain is recognized as a new class of conserved DNA-binding domain. The fly genome encodes three proteins that bear only a single BEN domain (“BEN-solo” factors); namely, Insensitive (Insv), Bsg25A (Elba1), and CG9883 (Elba2). Dai et al. identify both distinct and overlapping functional properties of these three Drosophila BEN-solo proteins, introducing unexpected complexity in their contributions to gene regulation and development. Recently, the BEN (BANP, E5R, and NAC1) domain was recognized as a new class of conserved DNA-binding domain. The fly genome encodes three proteins that bear only a single BEN domain (“BEN-solo” factors); namely, Insensitive (Insv), Bsg25A (Elba1), and CG9883 (Elba2). Insv homodimers preferentially bind CCAATTGG palindromes throughout the genome to mediate transcriptional repression, whereas Bsg25A and Elba2 heterotrimerize with their obligate adaptor, Elba3 (i.e., the ELBA complex), to recognize a CCAATAAG motif in the Fab-7 insulator. While these data suggest distinct DNA-binding properties of BEN-solo proteins, we performed reporter assays that indicate that both Bsg25A and Elba2 can individually recognize Insv consensus sites efficiently. We confirmed this by solving the structure of Bsg25A complexed to the Insv site, which showed that key aspects of the BEN:DNA recognition strategy are similar between these proteins. We next show that both Insv and ELBA proteins are competent to mediate transcriptional repression via Insv consensus sequences but that the ELBA complex appears to be selective for the ELBA site. Reciprocally, genome-wide analysis reveals that Insv exhibits significant cobinding to class I insulator elements, indicating that it may also contribute to insulator function. Indeed, we observed abundant Insv binding within the Hox complexes with substantial overlaps with class I insulators, many of which bear Insv consensus sites. Moreover, Insv coimmunoprecipitates with the class I insulator factor CP190. Finally, we observed that Insv harbors exclusive activity among fly BEN-solo factors with respect to regulation of Notch-mediated cell fate choices in the peripheral nervous system. This in vivo activity is recapitulated by BEND6, a mammalian BEN-solo factor that conserves the Notch corepressor function of Insv but not its capacity to bind Insv consensus sites. Altogether, our data define an array of common and distinct biochemical and functional properties of this new family of transcription factors.
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Affiliation(s)
- Qi Dai
- Department of Developmental Biology
| | - Aiming Ren
- Department of Structural Biology, Sloan-Kettering Institute New York, New York 10065, USA
| | | | | | - Dinshaw J Patel
- Department of Structural Biology, Sloan-Kettering Institute New York, New York 10065, USA
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18
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Abstract
Nac1 (nucleus accumbens 1) is a POZ (poxvirus and zinc finger)-domain transcriptional repressor that is expressed at high levels in ovarian serous carcinoma. Here we identify Nac1 as a novel interacting partner of the POZ-domain transcriptional activator, Miz1 (Myc-interacting zinc-finger protein 1), and using chemical crosslinking we show that this association is mediated by a heterodimeric interaction of the Nac1 and Miz1 POZ domains. Nac1 is found in discrete bodies within the nucleus of mammalian cells, and we demonstrate the relocalization of Miz1 to these structures in transfected HeLa cells. We show that siRNA (small interfering RNA)-mediated knockdown of Nac1 in ovarian cancer cells results in increased levels of the Miz1 target gene product, p21Cip1. The interaction of Nac1 with Miz1 may thus be relevant to its mechanism of tumourigenesis in ovarian cancer. Nac1 is a transcriptional repressor that has been implicated in ovarian serous carcinoma. Here we show that Nac1 interacts with the transcription factor Miz1, and suggest that this interaction may contribute to tumourigenesis.
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Dai Q, Andreu-Agullo C, Insolera R, Wong LC, Shi SH, Lai EC. BEND6 is a nuclear antagonist of Notch signaling during self-renewal of neural stem cells. Development 2013; 140:1892-902. [PMID: 23571214 DOI: 10.1242/dev.087502] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The activity of the Notch pathway revolves around a CSL-class transcription factor, which recruits distinct complexes that activate or repress target gene expression. The co-activator complex is deeply conserved and includes the cleaved Notch intracellular domain (NICD) and Mastermind. By contrast, numerous CSL co-repressor proteins have been identified, and these are mostly different between invertebrate and vertebrate systems. In this study, we demonstrate that mammalian BEND6 is a neural BEN-solo factor that shares many functional attributes with Drosophila Insensitive, a co-repressor for the Drosophila CSL factor. BEND6 binds the mammalian CSL protein CBF1 and antagonizes Notch-dependent target activation. In addition, its association with Notch- and CBF1-regulated enhancers is promoted by CBF1 and antagonized by activated Notch. In utero electroporation experiments showed that ectopic BEND6 inhibited Notch-mediated self-renewal of neocortical neural stem cells and promoted neurogenesis. Conversely, knockdown of BEND6 increased NSC self-renewal in wild-type neocortex, and exhibited genetic interactions with gain and loss of Notch pathway activity. We recapitulated all of these findings in cultured neurospheres, in which overexpression and depletion of BEND6 caused reciprocal effects on neural stem cell renewal and neurogenesis. These data reveal a novel mammalian CSL co-repressor in the nervous system, and show that the Notch-inhibitory activity of certain BEN-solo proteins is conserved between flies and mammals.
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Affiliation(s)
- Qi Dai
- Department of Developmental Biology, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA
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20
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Okazaki K, Nakayama N, Nariai Y, Nakayama K, Miyazaki K, Maruyama R, Kato H, Kosugi S, Urano T, Sakashita G. Nuclear localization signal in a cancer-related transcriptional regulator protein NAC1. Carcinogenesis 2012; 33:1854-62. [PMID: 22665369 DOI: 10.1093/carcin/bgs193] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Nucleus accumbens-associated protein 1 (NAC1) might have potential oncogenic properties and participate in regulatory networks for pluripotency. Although NAC1 is described as a transcriptional regulator, the nuclear import machinery of NAC1 remains unclear. We found, using a point mutant, that dimer formation was not committed to the nuclear localization of NAC1 and, using deletion mutants, that the amino-terminal half of NAC1 harbored a potential nuclear localization signal (NLS). Wild type, but not mutants of this region, alone was sufficient to drive the importation of green fluorescent protein (GFP) into the nucleus. Bimax1, a synthetic peptide that blocks the importin α/β pathway, impaired nuclear localization of NAC1 in cells. We also used the binding properties of importin to demonstrate that this region is an NLS. Furthermore, the transcriptional regulator function of NAC1 was dependent on its nuclear localization activity in cells. Taken together, these results show that the region with a bipartite motif constitutes a functional nuclear import sequence in NAC1 that is independent of NAC1 dimer formation. The identification of an NAC1 NLS thus clarifies the mechanism through which NAC1 translocates to the nucleus to regulate the transcription of genes involved in oncogenicity and pluripotency.
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Affiliation(s)
- Kosuke Okazaki
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Japan.
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21
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Fatty acid synthase expression associated with NAC1 is a potential therapeutic target in ovarian clear cell carcinomas. Br J Cancer 2012; 107:300-7. [PMID: 22653145 PMCID: PMC3394978 DOI: 10.1038/bjc.2012.246] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND This study examined the clinical significance of NAC1 and the expression level of its potential downstream target fatty acid synthase (FASN) in ovarian clear cell carcinomas (OCCCs), and evaluated the NAC1/FASN pathway as a potential therapeutic target. METHODS NAC1 and FASN expression and NACC1 gene amplification were assessed in ovarian cancers by immunohistochemistry, fluorescence in situ hybridisation, and clinical data collected by a retrospective chart review. C75, a FASN inhibitor, was used to assess whether this pathway represented a therapeutic target in OCCC. RESULTS High NAC1 expression was most frequent in clear cell tumours (40.0%:24/60). NACC1 gene amplification was identified in none of the 58 OCCCs. The frequency of NACC1 gene amplification was significantly higher in the high-grade serous histology than in the clear cell histology (P<0.01). NAC1 expression was significantly correlated with FASN expression in both OCCC samples and OCCC cell lines. Either high NAC1 expression or high FASN expression significantly correlated with shorter progression-free and overall survival (P=0.002 and 0.0048). NAC1 overexpression stimulated FASN expression, and NAC1 silencing using siRNA decreased FASN expression in OCCC cell lines. Profound growth inhibition was observed in C75-treated carcinoma cells with FASN overexpression when compared with the response in carcinoma cells without FASN expression. CONCLUSION These findings indicate that NAC1/FASN overexpression is critical to the growth and survival of a subset of OCCC. The FASN silencing by the C75-induced phenotypes depends on the expression status of the targeted cell line. Therefore, NAC1/FASN pathway-targeted therapy may benefit selected OCCC patients.
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Ramjan Ali M, Kim Y. A novel polydnaviral gene family, BEN, and its immunosuppressive function in larvae of Plutella xylostella parasitized by Cotesia plutellae. J Invertebr Pathol 2012; 110:389-97. [PMID: 22609480 DOI: 10.1016/j.jip.2012.05.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 04/30/2012] [Accepted: 05/07/2012] [Indexed: 11/19/2022]
Abstract
A full genome sequence of the episomal form of Cotesia plutellae bracovirus (CpBV) suggests 11 BEN family genes. This study analyzed their expression and physiological function in the viral host, Plutella xylostella. All 11 BEN family genes were expressed during entire parasitization period of P. xylostella larvae. In addition, these BEN family genes were expressed in fat body, gut, epidermis, and hemocytes in final larval instar of parasitized P. xylostella. The 11 BEN family genes were transiently expressed in nonparasitized larvae by injection of each viral segment containing its corresponding BEN family gene. The transient expression of BEN family genes significantly suppressed hemocyte nodule formation in response to bacterial challenge. Subsequent injection of double-stranded RNA specific to each BEN family gene suppressed the expression of the BEN family gene and rescued the immunosuppression. These results indicate that 11 BEN family genes are expressed in larvae parasitized by C. plutellae and play crucial role in inducing immunosuppression. Homologous BEN family genes were found in other bracoviral genomes. We propose BEN domain-containing genes as a new functional gene family in polydnaviruses.
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Affiliation(s)
- Md Ramjan Ali
- Department of Bioresource Sciences, Andong National University, Andong 760-749, Republic of Korea
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23
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Sathyan KM, Shen Z, Tripathi V, Prasanth KV, Prasanth SG. A BEN-domain-containing protein associates with heterochromatin and represses transcription. J Cell Sci 2012; 124:3149-63. [PMID: 21914818 DOI: 10.1242/jcs.086603] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In eukaryotes, higher order chromatin structure governs crucial cellular processes including DNA replication, transcription and post-transcriptional gene regulation. Specific chromatin-interacting proteins play vital roles in the maintenance of chromatin structure. We have identified BEND3, a quadruple BEN domain-containing protein that is highly conserved amongst vertebrates. BEND3 colocalizes with HP1 and H3 trimethylated at K9 at heterochromatic regions in mammalian cells. Using an in vivo gene locus, we have been able to demonstrate that BEND3 associates with the locus only when it is heterochromatic and dissociates upon activation of transcription. Furthermore, tethering BEND3 inhibits transcription from the locus, indicating that BEND3 is involved in transcriptional repression through its interaction with histone deacetylases and Sall4, a transcription repressor. We further demonstrate that BEND3 is SUMOylated and that such modifications are essential for its role in transcriptional repression. Finally, overexpression of BEND3 causes premature chromatin condensation and extensive heterochromatinization, resulting in cell cycle arrest. Taken together, our data demonstrate the role of a novel heterochromatin-associated protein in transcriptional repression.
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Affiliation(s)
- Kizhakke M Sathyan
- Department of Cell and Developmental Biology, University of Illinois, Urbana, IL 61801, USA
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24
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Södersten E, Lilja T, Hermanson O. The novel BTB/POZ and zinc finger factor Zbtb45 is essential for proper glial differentiation of neural and oligodendrocyte progenitor cells. Cell Cycle 2010; 9:4866-75. [PMID: 21131782 DOI: 10.4161/cc.9.24.14154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Understanding the regulatory mechanisms controlling the fate decisions of neural stem cells (NSCs) is a crucial issue to shed new light on mammalian central nervous system (CNS) development in health and disease. We have investigated a possible role for the previously uncharacterized BTB/POZ-domain containing zinc finger factor Zbtb45 in the differentiation of NSCs and postnatal oligodendrocyte precursors. In situ hybridization histochemistry and RT-qPCR analysis revealed that Zbtb45 mRNA was ubiquitously expressed in the developing CNS in mouse embryos at embryonic day (E) 12.5 and 14.5. Zbtb45 mRNA knockdown in embryonic forebrain NSCs by siRNA resulted in a rapid decrease in the expression of oligodendrocyte-characteristic genes after mitogen (FGF2) withdrawal, whereas the expression of astrocyte-associated genes such as CD44 and GFAP increased compared to control. Accordingly, the number of astrocytes was significantly increased seven days after Zbtb45 siRNA delivery to NSCs, in contrast to the numbers of neuronal and oligodendrocyte-like cells. Surprisingly, mRNA knockdown of the Zbtb45-associated factor Med31, a subunit of the Mediator complex, did not result in any detectable effect on NSC differentiation. Similar to NSCs, Zbtb45 mRNA knockdown in oligodendrocyte precursors (CG-4) reduced oligodendrocyte maturation upon mitogen withdrawal associated with down-regulation of the mRNA expression and protein levels of markers for oligodendrocytic differentiation. Zbtb45 mRNA knockdown did not significantly affect proliferation or cell death in any of the cell types. Based on these observations, we propose that Zbtb45 is a novel regulator of glial differentiation.
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Affiliation(s)
- Erik Södersten
- Linnaeus Center in Developmental Biology for Regenerative Medicine (DBRM), Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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25
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Transient transcription of a putative RNase containing BEN domain encoded in Cotesia plutellae bracovirus induces an immunosuppression of the diamondback moth, Plutella xylostella. J Invertebr Pathol 2010; 105:156-63. [DOI: 10.1016/j.jip.2010.06.003] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 06/02/2010] [Accepted: 06/03/2010] [Indexed: 11/22/2022]
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Expression of Fatty Acid Synthase Depends on NAC1 and Is Associated with Recurrent Ovarian Serous Carcinomas. JOURNAL OF ONCOLOGY 2010; 2010:285191. [PMID: 20508725 PMCID: PMC2873657 DOI: 10.1155/2010/285191] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/02/2010] [Accepted: 02/21/2010] [Indexed: 01/04/2023]
Abstract
Our previous reports demonstrated that NAC1, a BTB/POZ domain-containing nuclear protein, upregulates in recurrent ovarian serous carcinoma and participates in developing drug resistance in cancer cells. The current study applies quantitative proteomics to identify the proteins controlled by NAC1 by comparing the proteomes of SKOV3 cells with and without expression of a dominant negative NAC1 construct, N130. From the proteins that are downregulated by N130 (upregulated by NAC1), we chose to further characterize fatty acid synthase (FASN). Similar to change in protein level, the FASN transcript level in SKOV3 cells was significantly reduced by N130 induction or by NAC1 knockdown. Immunohistochemistry showed that NAC1 and FASN immunointensities in ovarian serous carcinoma tissues had a highly significant correlation (P < .0001). Moreover, we found that recurrent serous carcinomas exhibited higher FASN immunointensities than their matched primary tumors (P < .001). Multivariate analysis showed that an FASN staining score of >1 in serous carcinomas was associated with a worse overall survival time (P < .01). Finally, C93, a new FASN inhibitor, induced massive apoptosis in carboplatin/paclitaxel resistant ovarian cancer cells. In conclusion, we show that NAC1 is essential for FASN expression in ovarian serous carcinomas and the expression of FASN significantly correlates with tumor recurrence and disease aggressiveness. The dependence of drug resistant tumor cells on FASN suggests a potential application of FASN-based therapeutics for recurrent ovarian cancer patients.
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27
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Chandrasekar V, Dreyer JL. The Brain-Specific Neural Zinc Finger Transcription Factor 2b (NZF-2b/7ZFMyt1) Suppresses Cocaine Self-Administration in Rats. Front Behav Neurosci 2010; 4:14. [PMID: 20407577 PMCID: PMC2854526 DOI: 10.3389/fnbeh.2010.00014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 03/10/2010] [Indexed: 12/02/2022] Open
Abstract
Brain-specific neural-zinc-finger transcription factor-2b (NZF2b/7ZFMyt1) is induced in the mesolimbic dopaminergic region after chronic cocaine exposure and lentiviral-mediated expression of NZF2b/7ZFMyt1 in the nucleus accumbens results in decreased locomotor activity (Chandrasekar and Dreyer, 2010). In this study the role of NZF2b/7ZFMyt1 in active cocaine seeking and of its interaction with histone deacetylase on the altered behavior has been observed. Localized expression of NZF2b/7ZFMyt1 in the nucleus accumbens resulted in attenuated cocaine self-administration, whereas silencing this transcription factor with lentiviruses expressing siRNAs increased the animal′s motivation to self-infuse cocaine. Low doses of sodium butyrate, a potent inhibitor of histone deacetylase, were sufficient to reverse the NZF2b/7ZFMyt1-mediated decrease in cocaine self-administration. NZF2b/7ZFMyt1 expression resulted in strong induction of transcription factors REST1 and NAC1 and of the dopamine D2 receptor, with concomitant inhibition of BDNF and its receptor TrkB. We show that NZF2b/7ZFMyt1 colocalizes with histone deacetylase-2 (HDAC2), probably overcoming the suppression of transcriptional activity caused by Lingo1. These findings show that molecular adaptations mediated by NZF2b/7ZFMyt1 expression possibly lead to decreased responsiveness to the reinforcing properties of cocaine and play a prominent role in affecting the behavioral changes induced by the drug.
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Affiliation(s)
- Vijay Chandrasekar
- Division of Biochemistry, Department of Medicine, University of Fribourg Fribourg, Switzerland
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Chandrasekar V, Dreyer JL. The brain-specific Neural Zinc Finger transcription factor 2b (NZF-2b/7ZFMyt1) causes suppression of cocaine-induced locomotor activity. Neurobiol Dis 2009; 37:86-98. [PMID: 19786102 DOI: 10.1016/j.nbd.2009.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2009] [Revised: 09/03/2009] [Accepted: 09/15/2009] [Indexed: 01/29/2023] Open
Abstract
Chronic cocaine induces high expression of the brain-specific Neural-Zinc-Finger transcription factor-2b (NZF-2b/7ZFMyt1), particularly in the mesolimbic dopaminergic pathway, resulting in a 11-fold increase in NZF-2b/7ZFMyt1 expression in the Nucleus Accumbens (NAc). Overexpression of this gene in the NAc with a NZF-2b/7ZFMyt1-expressing lentivirus resulted in >55% decrease in locomotor activity upon chronic cocaine administration, compared to control animals. In contrast knocking-down the gene in the NAc with lentiviruses expressing shRNAs against NZF-2b/7ZFMyt1 induced strong hyperlocomotor activity upon cocaine. Strong inhibition of BDNF is observed upon NZF-2b/7ZFMyt1 expression, concomitant with strong induction of transcription factors REST1 (RE silencing transcription factor-1) and NAC1, probably leading to regulation of gene expression by interaction with histone deacetylases. These changes lead to decreased responsiveness of the animal to the locomotor-activating effects of cocaine, indicating that NZF-2b/7ZFMyt1 expression plays an important role in phenotypic changes induced by the drug.
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Affiliation(s)
- Vijay Chandrasekar
- Division of Biochemistry, Department of Medicine, University of Fribourg, Rue du Musée 5, CH-1700 Fribourg, Switzerland
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Jinawath N, Vasoontara C, Yap KL, Thiaville MM, Nakayama K, Wang TL, Shih IM. NAC-1, a potential stem cell pluripotency factor, contributes to paclitaxel resistance in ovarian cancer through inactivating Gadd45 pathway. Oncogene 2009; 28:1941-8. [PMID: 19305429 PMCID: PMC2679096 DOI: 10.1038/onc.2009.37] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 02/18/2009] [Accepted: 02/19/2009] [Indexed: 01/06/2023]
Abstract
Nucleus accumbens-1 (Nac1 or NAC-1) belongs to the BTB/POZ (Pox virus and Zinc finger/Bric-a-brac Tramtrack Broad complex) transcription factor family and is a novel protein that potentially participates in self-renewal and pluripotency in embryonic stem cells. In human cancer, NAC-1 is upregulated in several types of neoplasms, but particularly in recurrent chemoresistant ovarian carcinomas, suggesting a biological role for NAC-1 in the development of drug resistance in ovarian cancer. We have assessed this possibility and shown a correlation between NAC-1 expression and ex vivo paclitaxel resistance in ovarian serous carcinoma tissues and cell lines. We found that expression of Gadd45-gamma-interacting protein 1 (Gadd45gip1), a downstream target negatively regulated by NAC-1, was reduced in paclitaxel-resistant cells. Ectopic expression of NAC-1 or knockdown of Gadd45gip1 conferred paclitaxel resistance, whereas NAC-1 knockdown or ectopic expression of Gadd45gip1 increased paclitaxel sensitivity. Furthermore, silencing NAC-1 expression or disrupting NAC-1 homodimerization by a dominant negative NAC-1 protein that contained only the BTB/POZ domain induced the expression of Gadd45gamma, which interacted with Gadd45gip1. Reducing Gadd45gamma expression by small hairpin RNAs partially enhanced paclitaxel resistance. Thus, this study provides new evidence that NAC-1 upregulation and homodimerization contribute to tumor recurrence by equipping ovarian cancer cells with the paclitaxel-resistant phenotype through negative regulation of the Gadd45 pathway.
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Affiliation(s)
- Natini Jinawath
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
| | - Chanont Vasoontara
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
| | - Kai-Lee Yap
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
| | - Michelle M. Thiaville
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
| | - Kentaro Nakayama
- Department of Gynecology and Obstetrics, Shimane University, Izumo, 6930024, Japan
| | - Tian-Li Wang
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
| | - Ie-Ming Shih
- Departments of Pathology, Oncology, and Gynecology and Obstetrics, Johns Hopkins Medical Institutions, Baltimore, Maryland, 21231, USA
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Stead MA, Carr SB, Wright SC. Structure of the human Nac1 POZ domain. Acta Crystallogr Sect F Struct Biol Cryst Commun 2009; 65:445-9. [PMID: 19407373 PMCID: PMC2675581 DOI: 10.1107/s1744309109012214] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 04/01/2009] [Indexed: 11/10/2022]
Abstract
Nac1 is a POZ-domain transcription factor that is involved in the self-renewal of embryonic stem cells. It is overexpressed in ovarian serous carcinoma and targeting the interactions of its POZ domain is a potential therapeutic strategy. Nac1 lacks a zinc-finger DNA-binding domain and thereby differs from most other POZ-domain transcription factors. Here, the crystal structure of the Nac1 POZ domain at 2.1 A resolution is reported. The Nac1 POZ domain crystallized as a dimer in which the interaction interfaces between subunits resemble those found in the POZ-zinc finger transcription factors. The organization of the Nac1 POZ-domain core resembles reported POZ-domain structures, whereas the C-terminus differs markedly. The C-terminal alpha-helix of the Nac1 POZ domain is shorter than that observed in most other POZ-domain transcription factors; variation in the organization of this region may be a general feature of POZ-domain structures.
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Affiliation(s)
- Mark A. Stead
- Molecular Cell Biology Research Group, Garstang Building, Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, England
| | - Stephen B. Carr
- Membrane Protein Laboratory, Diamond Light Source, Harwell Science and Innovation Campus, Chilton, Didcot OX11 0DE, England
| | - Stephanie C. Wright
- Molecular Cell Biology Research Group, Garstang Building, Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, England
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NAC1, a POZ/BTB protein that functions as a corepressor. Neurochem Int 2008; 54:245-52. [PMID: 19121354 DOI: 10.1016/j.neuint.2008.12.008] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 11/25/2008] [Accepted: 12/02/2008] [Indexed: 11/20/2022]
Abstract
We now demonstrate that NAC1 acts as a corepressor for other POZ/BTB proteins. NAC1 is a POZ/BTB motif containing transcriptional repressor protein. In a mammalian two hybrid assay in neuronal (N2A) cells and non-neuronal (HEK 293T) cells, VP16 activation domain tagged NAC1 resulted in significant reversal of transcriptional inhibition with the Gal4-ZID, Gal4-BCL6, Gal4-ZF5, and kelch proteins Gal4-MAYVEN and Gal4-NRP/B fusion proteins. We also observed similar results with another corepressor, BCoR Gal4 fusion protein. NAC1 potentiated ZF5 mediated repression in Gal4-DBD fusion transient assays. GST pulldown assays further confirmed protein-protein interactions between these proteins and NAC1. Both the NAC1 isoforms demonstrated selective interaction through the POZ/BTB domain but not with the non-POZ/BTB region. Endogenous NAC1 and BCL6 physically associated in CNS regions. Strikingly, NAC1 did not interact with the pro-myelocytic leukemia zinc finger protein (PLZF), another POZ/BTB protein that is not found in the adult brain. Therefore, we conclude that NAC1 functions as a corepressor for POZ/BTB proteins expressed in the mature CNS.
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Abhiman S, Iyer LM, Aravind L. BEN: a novel domain in chromatin factors and DNA viral proteins. ACTA ACUST UNITED AC 2008; 24:458-61. [PMID: 18203771 DOI: 10.1093/bioinformatics/btn007] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We report a previously uncharacterized alpha-helical module, the BEN domain, in diverse animal proteins such as BANP/SMAR1, NAC1 and the Drosophila mod(mdg4) isoform C, in the chordopoxvirus virosomal protein E5R and in several proteins of polydnaviruses. Contextual analysis suggests that the BEN domain mediates protein-DNA and protein-protein interactions during chromatin organization and transcription. The presence of BEN domains in a poxviral early virosomal protein and in polydnaviral proteins also suggests a possible role for them in organization of viral DNA during replication or transcription.
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Affiliation(s)
- Saraswathi Abhiman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
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