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Kohl B, Zhong X, Herrmann C, Stoll R. Phosphorylation orchestrates the structural ensemble of the intrinsically disordered protein HMGA1a and modulates its DNA binding to the NFκB promoter. Nucleic Acids Res 2020; 47:11906-11920. [PMID: 31340016 PMCID: PMC7145567 DOI: 10.1093/nar/gkz614] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2019] [Revised: 06/14/2019] [Accepted: 07/05/2019] [Indexed: 12/27/2022] Open
Abstract
High Mobility Group Protein A1a (HMGA1a) is a highly abundant nuclear protein, which plays a crucial role during embryogenesis, cell differentiation, and neoplasia. Here, we present the first ever NMR-based structural ensemble of full length HMGA1a. Our results show that the protein is not completely random coil but adopts a compact structure consisting of transient long-range contacts, which is regulated by post-translational phosphorylation. The CK2-, cdc2- and cdc2/CK2-phosphorylated forms of HMGA1a each exhibit a different binding affinity towards the PRD2 element of the NFκB promoter. Our study identifies connected regions between phosphorylation sites in the wildtype ensemble that change considerably upon phosphorylation, indicating that these posttranslational modifications sites are part of an electrostatic contact network that alters the structural ensemble by shifting the conformational equilibrium. Moreover, ITC data reveal that the CK2-phosphorylated HMGA1a exhibits a different DNA promoter binding affinity for the PRD2 element. Furthermore, we present the first structural model for AT-hook 1 of HMGA1a that can adopt a transient α-helical structure, which might serve as an additional regulatory mechanism in HMAG1a. Our findings will help to develop new therapeutic strategies against HMGA1a-associated cancers by taking posttranslational modifications into consideration.
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Affiliation(s)
- Bastian Kohl
- Faculty of Chemistry and Biochemistry, Biomolecular NMR Spectroscopy, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Xueyin Zhong
- Faculty of Chemistry and Biochemistry, Biomolecular NMR Spectroscopy, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Christian Herrmann
- Faculty of Chemistry and Biochemistry, Protein Interactions, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Raphael Stoll
- Faculty of Chemistry and Biochemistry, Biomolecular NMR Spectroscopy, Ruhr University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
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52
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The Mammalian High Mobility Group Protein AT-Hook 2 (HMGA2): Biochemical and Biophysical Properties, and Its Association with Adipogenesis. Int J Mol Sci 2020; 21:ijms21103710. [PMID: 32466162 PMCID: PMC7279267 DOI: 10.3390/ijms21103710] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/30/2020] [Accepted: 05/12/2020] [Indexed: 12/11/2022] Open
Abstract
The mammalian high-mobility-group protein AT-hook 2 (HMGA2) is a small DNA-binding protein and consists of three “AT-hook” DNA-binding motifs and a negatively charged C-terminal motif. It is a multifunctional nuclear protein directly linked to obesity, human height, stem cell youth, human intelligence, and tumorigenesis. Biochemical and biophysical studies showed that HMGA2 is an intrinsically disordered protein (IDP) and could form homodimers in aqueous buffer solution. The “AT-hook” DNA-binding motifs specifically bind to the minor groove of AT-rich DNA sequences and induce DNA-bending. HMGA2 plays an important role in adipogenesis most likely through stimulating the proliferative expansion of preadipocytes and also through regulating the expression of transcriptional factor Peroxisome proliferator-activated receptor γ (PPARγ) at the clonal expansion step from preadipocytes to adipocytes. Current evidence suggests that a main function of HMGA2 is to maintain stemness and renewal capacity of stem cells by which HMGA2 binds to chromosome and lock chromosome into a specific state, to allow the human embryonic stem cells to maintain their stem cell potency. Due to the importance of HMGA2 in adipogenesis and tumorigenesis, HMGA2 is considered a potential therapeutic target for anticancer and anti-obesity drugs. Efforts are taken to identify inhibitors targeting HMGA2.
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Ouchi K, Miyachi M, Yagyu S, Kikuchi K, Kuwahara Y, Tsuchiya K, Iehara T, Hosoi H. Oncogenic role of HMGA2 in fusion-negative rhabdomyosarcoma cells. Cancer Cell Int 2020; 20:192. [PMID: 32489328 PMCID: PMC7247181 DOI: 10.1186/s12935-020-01282-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 05/19/2020] [Indexed: 11/21/2022] Open
Abstract
Background Rhabdomyosarcoma (RMS) is the most common pediatric soft tissue sarcoma. There are two subtypes, fusion gene-positive RMS (FP-RMS) and fusion gene-negative RMS (FN-RMS), depending on the presence of a fusion gene, either PAX3-FOXO1 or PAX7-FOXO1. These fusion genes are thought to be oncogenic drivers of FP-RMS. By contrast, the underlying mechanism of FN-RMS has not been thoroughly investigated. It has recently been shown that HMGA2 is specifically positive in pathological tissue from FN-RMS, but the role of HMGA2 in FN-RMS remains to be clarified. Methods In this study, we used FN-RMS cell lines to investigate the function of HMGA2. Gene expression, cell growth, cell cycle, myogenic differentiation, tumor formation in vivo, and cell viability under drug treatment were assessed. Results We found that HMGA2 was highly expressed in FN-RMS cells compared with FP-RMS cells and that knockdown of HMGA2 in FN-RMS cells inhibited cell growth and induced G1 phase accumulation in the cell cycle and myogenic differentiation. Additionally, we showed using both gain-of-function and loss-of-function assays that HMGA2 was required for tumor formation in vivo. Consistent with these findings, the HMGA2 inhibitor netropsin inhibited the cell growth of FN-RMS. Conclusions Our results suggest that HMGA2 has important role in the oncogenicity of FP-RMS and may be a potential therapeutic target in patients with FN-RMS.
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Affiliation(s)
- Kazutaka Ouchi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Mitsuru Miyachi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Shigeki Yagyu
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Ken Kikuchi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Yasumichi Kuwahara
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan.,Department of Molecular Biochemistry, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Kunihiko Tsuchiya
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Tomoko Iehara
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
| | - Hajime Hosoi
- Department of Pediatrics, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Hirokoji, Kamigyo-ku, Kyoto, 602-8566 Japan
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Redaelli S, Conconi D, Villa N, Sala E, Crosti F, Corti C, Catusi I, Garzo M, Romitti L, Martinoli E, Patrizi A, Malgara R, Recalcati MP, Dalprà L, Lavitrano M, Riva P, Roversi G, Bentivegna A. Instability of Short Arm of Acrocentric Chromosomes: Lesson from Non-Acrocentric Satellited Chromosomes. Report of 24 Unrelated Cases. Int J Mol Sci 2020; 21:ijms21103431. [PMID: 32413994 PMCID: PMC7279238 DOI: 10.3390/ijms21103431] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 05/09/2020] [Accepted: 05/11/2020] [Indexed: 01/13/2023] Open
Abstract
Satellited non-acrocentric autosomal chromosomes (ps–qs-chromosomes) are the result of an interchange between sub- or telomeric regions of autosomes and the p arm of acrocentrics. The sequence homology at the rearrangement breakpoints appears to be, among others, the most frequent mechanism generating these variant chromosomes. The unbalanced carriers of this type of translocation may or may not display phenotypic abnormalities. With the aim to understand the causative mechanism, we revised all the ps–qs-chromosomes identified in five medical genetics laboratories, which used the same procedures for karyotype analysis, reporting 24 unrelated cases involving eight chromosomes. In conclusion, we observed three different scenarios: true translocation, benign variant and complex rearrangement. The detection of translocation partners is essential to evaluate possible euchromatic unbalances and to infer their effect on phenotype. Moreover, we emphasize the importance to perform both, molecular and conventional cytogenetics methods, to better understand the behavior of our genome.
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Affiliation(s)
- Serena Redaelli
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Donatella Conconi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Nicoletta Villa
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Elena Sala
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Francesca Crosti
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Cecilia Corti
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Ilaria Catusi
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Maria Garzo
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Lorenza Romitti
- Pathology and Cytogenetics Laboratory, Clinical Pathology Department, Niguarda Ca’ Granda Hospital, 20162 Milan, Italy;
| | - Emanuela Martinoli
- Medical Genetics Laboratory, Medical Biotechnology and Translational Medicine Department, University of Milan, 20090 Milan, Italy; (E.M.); (P.R.)
| | - Antonella Patrizi
- Medical Cytogenetics Laboratory, Clinical Pathology Department, San Paolo Hospital, 20142 Milan, Italy; (A.P.); (R.M.)
| | - Roberta Malgara
- Medical Cytogenetics Laboratory, Clinical Pathology Department, San Paolo Hospital, 20142 Milan, Italy; (A.P.); (R.M.)
| | - Maria Paola Recalcati
- Medical Cytogenetics Laboratory, Istituto Auxologico Italiano IRCCS, 20095 Cusano Milanino, Italy; (C.C.); (I.C.); (M.G.); (M.P.R.)
| | - Leda Dalprà
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
- Medical Genetics Laboratory, Clinical Pathology Department, S. Gerardo Hospital, 20900 Monza, Italy; (N.V.); (E.S.); (F.C.)
| | - Marialuisa Lavitrano
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Paola Riva
- Medical Genetics Laboratory, Medical Biotechnology and Translational Medicine Department, University of Milan, 20090 Milan, Italy; (E.M.); (P.R.)
| | - Gaia Roversi
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
| | - Angela Bentivegna
- School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy; (S.R.); (D.C.); (L.D.); (M.L.); (G.R.)
- Correspondence: ; Tel.: +39-0264488133
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Drosophila P75 safeguards oogenesis by preventing H3K9me2 spreading. J Genet Genomics 2020; 47:187-199. [PMID: 32499180 DOI: 10.1016/j.jgg.2020.02.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 02/25/2020] [Accepted: 02/26/2020] [Indexed: 11/22/2022]
Abstract
Serving as a host factor for human immunodeficiency virus (HIV) integration, LEDGF/p75 has been under extensive study as a potential target for therapy. However, as a highly conserved protein, its physiological function remains to be thoroughly elucidated. Here, we characterize the molecular function of dP75, the Drosophila homolog of LEDGF/p75, during oogenesis. dP75 binds to transcriptionally active chromatin with its PWWP domain. The C-terminus integrase-binding domain-containing region of dP75 physically interacts with the histone kinase Jil-1 and stabilizes it in vivo. Together with Jil-1, dP75 prevents the spreading of the heterochromatin mark-H3K9me2-onto genes required for oogenesis and piRNA production. Without dP75, ectopical silencing of these genes disrupts oogenesis, activates transposons, and causes animal sterility. We propose that dP75, the homolog of an HIV host factor in Drosophila, partners with and stabilizes Jil-1 to ensure gene expression during oogenesis by preventing ectopic heterochromatin spreading.
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Yang J, Chen S, Yang Y, Ma X, Shao B, Yang S, Wei Y, Wei X. Jumonji domain-containing protein 6 protein and its role in cancer. Cell Prolif 2020; 53:e12747. [PMID: 31961032 PMCID: PMC7046477 DOI: 10.1111/cpr.12747] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2019] [Revised: 11/29/2019] [Accepted: 12/02/2019] [Indexed: 02/05/2023] Open
Abstract
The jumonji domain‐containing protein 6 (JMJD6) is a Fe(II)‐ and 2‐oxoglutarate (2OG)‐dependent oxygenase that catalyses lysine hydroxylation and arginine demethylation of histone and non‐histone peptides. Recently, the intrinsic tyrosine kinase activity of JMJD6 has also been reported. The JMJD6 has been implicated in embryonic development, cellular proliferation and migration, self‐tolerance induction in the thymus, and adipocyte differentiation. Not surprisingly, abnormal expression of JMJD6 may contribute to the development of many diseases, such as neuropathic pain, foot‐and‐mouth disease, gestational diabetes mellitus, hepatitis C and various types of cancer. In the present review, we summarized the structure and functions of JMJD6, with particular emphasis on the role of JMJD6 in cancer progression.
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Affiliation(s)
- Jing Yang
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Siyuan Chen
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yanfei Yang
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xuelei Ma
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Bin Shao
- State Key Laboratory of Oral Disease, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan, China
| | - Shengyong Yang
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Yuquan Wei
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
| | - Xiawei Wei
- Laboratory of Aging Research and Nanotoxicology, State Key Laboratory of Biotherapy and Cancer Center, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, Sichuan, China
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HMGA Genes and Proteins in Development and Evolution. Int J Mol Sci 2020; 21:ijms21020654. [PMID: 31963852 PMCID: PMC7013770 DOI: 10.3390/ijms21020654] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/14/2020] [Accepted: 01/16/2020] [Indexed: 12/16/2022] Open
Abstract
HMGA (high mobility group A) (HMGA1 and HMGA2) are small non-histone proteins that can bind DNA and modify chromatin state, thus modulating the accessibility of regulatory factors to the DNA and contributing to the overall panorama of gene expression tuning. In general, they are abundantly expressed during embryogenesis, but are downregulated in the adult differentiated tissues. In the present review, we summarize some aspects of their role during development, also dealing with relevant studies that have shed light on their functioning in cell biology and with emerging possible involvement of HMGA1 and HMGA2 in evolutionary biology.
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Piccolo FM, Liu Z, Dong P, Hsu CL, Stoyanova EI, Rao A, Tjian R, Heintz N. MeCP2 nuclear dynamics in live neurons results from low and high affinity chromatin interactions. eLife 2019; 8:51449. [PMID: 31868585 PMCID: PMC6957317 DOI: 10.7554/elife.51449] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 12/22/2019] [Indexed: 01/08/2023] Open
Abstract
Methyl-CpG-binding-Protein 2 (MeCP2) is an abundant nuclear protein highly enriched in neurons. Here we report live-cell single-molecule imaging studies of the kinetic features of mouse MeCP2 at high spatial-temporal resolution. MeCP2 displays dynamic features that are distinct from both highly mobile transcription factors and immobile histones. Stable binding of MeCP2 in living neurons requires its methyl-binding domain and is sensitive to DNA modification levels. Diffusion of unbound MeCP2 is strongly constrained by weak, transient interactions mediated primarily by its AT-hook domains, and varies with the level of chromatin compaction and cell type. These findings extend previous studies of the role of the MeCP2 MBD in high affinity DNA binding to living neurons, and identify a new role for its AT-hooks domains as critical determinants of its kinetic behavior. They suggest that limited nuclear diffusion of MeCP2 in live neurons contributes to its local impact on chromatin structure and gene expression.
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Affiliation(s)
- Francesco M Piccolo
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Zhe Liu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Peng Dong
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Ching-Lung Hsu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Elitsa I Stoyanova
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
| | - Anjana Rao
- La Jolla Institute for Allergy and Immunology, La Jolla, United States
| | - Robert Tjian
- Department of Molecular and Cell Biology, Li Ka Shing Center for Biomedical and Health Sciences, CIRM Center of Excellence, University of California, Howard Hughes Medical Institute, Berkeley, United States
| | - Nathaniel Heintz
- Laboratory of Molecular Biology, Howard Hughes Medical Institute, The Rockefeller University, New York, United States
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Ahmed SM, Dröge P. Oncofetal HMGA2 attenuates genotoxic damage induced by topoisomerase II target compounds through the regulation of local DNA topology. Mol Oncol 2019; 13:2062-2078. [PMID: 31271486 PMCID: PMC6763970 DOI: 10.1002/1878-0261.12541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Revised: 06/26/2019] [Accepted: 07/03/2019] [Indexed: 12/26/2022] Open
Abstract
Rapidly dividing cells maintain chromatin supercoiling homeostasis via two specialized classes of enzymes, DNA topoisomerase type 1 and 2 (TOP1/2). Several important anticancer drugs perturb this homeostasis by targeting TOP1/2, thereby generating genotoxic DNA damage. Our recent studies indicated that the oncofetal chromatin structuring high‐mobility group AT‐hook 2 (HMGA2) protein plays an important role as a DNA replication fork chaperone in coping with DNA topological ramifications that occur during replication stress, both genomewide and at fragile sites such as subtelomeres. Intriguingly, a recent large‐scale clinical study identified HMGA2 expression as a sole predicting marker for relapse and poor clinical outcomes in 350 acute myeloid leukemia (AML) patients receiving combinatorial treatments that targeted TOP2 and replicative DNA synthesis. Here, we demonstrate that HMGA2 significantly enhanced the DNA supercoil relaxation activity of the drug target TOP2A and that this activator function is mechanistically linked to HMGA2's known ability to constrain DNA supercoils within highly compacted ternary complexes. Furthermore, we show that HMGA2 significantly reduced genotoxic DNA damage in each tested cancer cell model during treatment with the TOP2A poison etoposide or the catalytic TOP2A inhibitor merbarone. Taken together with the recent clinical data obtained with AML patients targeted with TOP2 poisons, our study suggests a novel mechanism of cancer chemoresistance toward combination therapies administering TOP2 poisons or inhibitors. We therefore strongly argue for the future implementation of trials of HMGA2 expression profiling to stratify patients before finalizing clinical treatment regimes.
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Affiliation(s)
- Syed Moiz Ahmed
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Peter Dröge
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
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Reyes-Gutierrez P, Carrasquillo-Rodríguez JW, Imbalzano AN. Promotion of adipogenesis by JMJD6 requires the AT hook-like domain and is independent of its catalytic function. PLoS One 2019; 14:e0216015. [PMID: 31430278 PMCID: PMC6701753 DOI: 10.1371/journal.pone.0216015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 08/03/2019] [Indexed: 12/25/2022] Open
Abstract
JMJD6 is a member of the Jumonji C domain containing enzymes that demethylate and/or hydroxylate substrate proteins. It is a multi-functional protein that has been implicated in disparate aspects of transcriptional and post-transcriptional control of gene expression, including but not limited to enhancer and promoter binding, release of paused RNA polymerase II, control of splicing, and interaction with the translation machinery. JMJD6 contributes to multiple aspects of animal development, including adipogenesis modeled in culture. We mutated proposed or characterized domains in the JMJD6 protein to better understand the requirement for JMJD6 in adipogenic differentiation. Mutation of JMJD6 amino acids that mediate binding of iron and 2-oxogluterate, which are required cofactors for enzymatic activity, had no impact on JMJD6 function, showing that catalytic activity is not required for JMJD6 contributions to adipogenic differentiation. In addition, we documented the formation of JMJD6 oligomers and showed that catalytic activity is not required for oligomerization, as has been reported previously. We also observed no effect of mutations in the sumoylation site and in the poly-serine stretch. In contrast, mutation of the AT hook-like structure, which mediates interaction with DNA and/or RNA, compromised JMJD6 function by blocking its ability to interact with chromatin at genes that express regulators of adipogenesis. The ability of JMJD6 to interact with nucleic acids may be a critical requirement for its function in adipogenic differentiation. The requirement for the AT hook-like domain and the lack of requirement for catalytic activity giving rise to the idea that co-activation of transcription by JMJD6 may be functioning as a scaffold protein that supports the interactions of other critical regulators.
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Affiliation(s)
- Pablo Reyes-Gutierrez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Jake W. Carrasquillo-Rodríguez
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Anthony N. Imbalzano
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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Adenomyoepitheliomas of the Breast Frequently Harbor Recurrent Hotspot Mutations in PIK3-AKT Pathway-related Genes and a Subset Show Genetic Similarity to Salivary Gland Epithelial-Myoepithelial Carcinoma. Am J Surg Pathol 2019; 43:1005-1013. [DOI: 10.1097/pas.0000000000001275] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Portovedo S, Gaido N, de Almeida Nunes B, Nascimento AG, Rocha A, Magalhães M, Nascimento GC, Pires de Carvalho D, Soares P, Takiya C, Faria MDS, Miranda-Alves L. Differential Expression of HMGA1 and HMGA2 in pituitary neuroendocrine tumors. Mol Cell Endocrinol 2019; 490:80-87. [PMID: 30999005 DOI: 10.1016/j.mce.2019.04.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 04/05/2019] [Accepted: 04/12/2019] [Indexed: 02/06/2023]
Abstract
Defining biomarkers for invasive pituitary neuroendocrine tumors (PitNETs) is highly desirable. The high mobility group A (HMGA) proteins are among the most widely expressed cancer-associated proteins. Indeed, their overexpression is a frequent feature of human malignancies, including PitNETs. We show that nonfunctioning PitNETs (NF-PitNETs) express significantly higher levels of HMGA1 than somatotropinomas (GHs) and corticotropinomas (ACTHs). Furthermore, HMGA2 expression was detected only in NF-PitNETs and was significantly higher in larger tumors than in smaller tumors. HMGA expression analysis generally focuses on nuclear staining. Here, cytoplasmic HMGA staining was also found. PitNETs displayed strong nuclear HMGA1 and strong cytoplasmic HMGA2 immunoreactivity. Interestingly, the HMGA1 and HMGA2 nuclear expression levels were significantly higher in invasive adenomas than in noninvasive adenomas. The highest levels of nuclear HMGA2 were found in GHs. In conclusion, we show that overexpression of nuclear HMGA proteins could be a potential biomarker of invasive PitNETs, particularly HMGA2 for GHs. HMGA2 might be a reliable biomarker for NF-PitNETs.
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Affiliation(s)
- Sérgio Portovedo
- Laboratory of Experimental Endocrinology - LEEx, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Graduate Program in Endocrinology, Faculty of Medicine, Federal University of Rio de Janeiro, Brazil
| | - Nadja Gaido
- Service of Endocrinology, President Dutra Hospital of the Federal University of Maranhão and Clinical Research Center of the President Dutra Hospital of the Federal University of Maranhão, Brazil
| | - Bruno de Almeida Nunes
- Laboratory of Experimental Endocrinology - LEEx, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Graduate Program in Endocrinology, Faculty of Medicine, Federal University of Rio de Janeiro, Brazil
| | - Ana Giselia Nascimento
- Service of Pathology, President Dutra Hospital of the Federal University of Maranhão, Brazil
| | - Allysson Rocha
- Department of Radiology and Diagnostic Imaging, President Dutra Hospital, Federal University of Maranhão, Brazil
| | - Marcelo Magalhães
- Service of Endocrinology, President Dutra Hospital of the Federal University of Maranhão and Clinical Research Center of the President Dutra Hospital of the Federal University of Maranhão, Brazil
| | - Gilvan Cortes Nascimento
- Service of Endocrinology, President Dutra Hospital of the Federal University of Maranhão and Clinical Research Center of the President Dutra Hospital of the Federal University of Maranhão, Brazil
| | - Denise Pires de Carvalho
- Graduate Program in Endocrinology, Faculty of Medicine, Federal University of Rio de Janeiro, Brazil; Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Brazil
| | - Paula Soares
- Laboratory of Experimental Endocrinology - LEEx, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Graduate Program in Endocrinology, Faculty of Medicine, Federal University of Rio de Janeiro, Brazil; Institute for Research and Innovation in Health (I3S), University of Porto, Portugal; Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP) - Cancer Signaling & Metabolism, Portugal; Department of Pathology, Faculty of Medicine, University of Porto, Portugal
| | - Christina Takiya
- Biophysics Institute Carlos Chagas Filho, Federal University of Rio de Janeiro, Brazil
| | - Manuel Dos Santos Faria
- Laboratory of Experimental Endocrinology - LEEx, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Service of Endocrinology, President Dutra Hospital of the Federal University of Maranhão and Clinical Research Center of the President Dutra Hospital of the Federal University of Maranhão, Brazil
| | - Leandro Miranda-Alves
- Laboratory of Experimental Endocrinology - LEEx, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil; Graduate Program in Endocrinology, Faculty of Medicine, Federal University of Rio de Janeiro, Brazil; Graduate Program in Pharmacology and Medicinal Chemistry, Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil.
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Park J, Lee S, Won N, Shin E, Kim SH, Chun MY, Gu J, Jung GY, Lim KI, Jo K. Single-molecule DNA visualization using AT-specific red and non-specific green DNA-binding fluorescent proteins. Analyst 2019; 144:921-927. [PMID: 30310901 DOI: 10.1039/c8an01426d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The recent advances in the single cell genome analysis are generating a considerable amount of novel insights into complex biological systems. However, there are still technical challenges because each cell has a single copy of DNA to be amplified in most single cell genome analytical methods. In this paper, we present a novel approach to directly visualize a genomic map on a large DNA molecule instantly stained with red and green DNA-binding fluorescent proteins without DNA amplification. For this visualization, we constructed a few types of fluorescent protein-fused DNA-binding proteins: H-NS (histone-like nucleoid-structuring protein), DNA-binding domain of BRCA1 (breast cancer 1), high mobility group-1 (HMG), and lysine tryptophan (KW) repeat motif. Because H-NS and HMG preferentially bind A/T-rich regions, we combined A/T specific binder (H-NS-mCherry and HMG-mCherry as red color) and a non-specific complementary DNA binder (BRCA1-eGFP and 2(KW)2-eGFP repeat as green color) to produce a sequence-specific two-color DNA physical map for efficient optical identification of single DNA molecules.
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Affiliation(s)
- Jihyun Park
- Department of Chemistry and Interdisciplinary Program of Integrated Biotech, Sogang University, 1 Shinsudong, Mapogu, Seoul, 04107, Korea.
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Li M, Zhao H, Zhao SG, Wei DM, Zhao YR, Huang T, Muhammad T, Yan L, Gao F, Li L, Lu G, Chan WY, Leung PCK, Dunaif A, Liu HB, Chen ZJ. The HMGA2-IMP2 Pathway Promotes Granulosa Cell Proliferation in Polycystic Ovary Syndrome. J Clin Endocrinol Metab 2019; 104:1049-1059. [PMID: 30247605 PMCID: PMC6753588 DOI: 10.1210/jc.2018-00544] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 09/18/2018] [Indexed: 12/19/2022]
Abstract
CONTEXT The high mobility group AT hook 2 (HMGA2) gene was previously identified in a genome-wide association study as a candidate risk gene that might be related to polycystic ovary syndrome (PCOS). Whether HMGA2 contributes to promoting granulosa cell (GC) proliferation in PCOS remains unknown. OBJECTIVE We sought to determine whether HMGA2 is involved in the ovarian dysfunction of PCOS and in the mechanism of increased GC proliferation. PATIENTS AND CELLS mRNA expression was analyzed in ovarian GCs from 96 women with PCOS and 58 healthy controls. Immortalized human GCs (KGN and SVOG cells) were used for the mechanism study. MAIN OUTCOME MEASURES mRNA expression in ovarian GCs was measured using quantitative RT-PCR, and KGN cells were cultured for proliferation assays after overexpression or knockdown of target genes. Protein expression analysis, luciferase assays, and RNA binding protein immunoprecipitation assays were used to confirm the mechanism study. RESULTS HMGA2 and IGF2 mRNA binding protein 2 (IMP2) were highly expressed in the GCs of women with PCOS, and the HMGA2/IMP2 pathway promoted GC proliferation. Cyclin D2 and SERPINE1 mRNA binding protein 1 were regulated by IMP2 and were highly expressed in women with PCOS. CONCLUSIONS The HMGA2/IMP2 pathway was activated in women with PCOS and promoted the proliferation of GCs. This might provide new insights into the dysfunction of GCs in PCOS.
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Affiliation(s)
- Miao Li
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Han Zhao
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Shi-Gang Zhao
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Dai-Min Wei
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Yue-Ran Zhao
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Tao Huang
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Tahir Muhammad
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Lei Yan
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
| | - Fei Gao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Lei Li
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
- Department of Biological Sciences, University of Notre Dame, Notre Dame, Indiana
| | - Gang Lu
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - Wai-Yee Chan
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China
| | - Peter C K Leung
- Department of Obstetrics and Gynaecology, Child and Family Research Institute, University of British Columbia, Vancouver, Canada
| | | | - Hong-Bin Liu
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
- CUHK-SDU Joint Laboratory on Reproductive Genetics, School of Biomedical Sciences, the Chinese University of Hong Kong, Hong Kong, China
- Correspondence and Reprint Requests: Hong-Bin Liu, PhD, or Zi-Jiang Chen, MD, PhD, Center for Reproductive Medicine, Shandong University, No. 157 Jingliu Road, Jinan 250001, China. E-mail: or
| | - Zi-Jiang Chen
- Center for Reproductive Medicine, Shandong University, Jinan, China
- National Research Center for Assisted Reproductive Technology and Reproductive Genetics, Jinan, China
- The Key Laboratory of Reproductive Endocrinology (Shandong University), Ministry of Education, Jinan, China
- Correspondence and Reprint Requests: Hong-Bin Liu, PhD, or Zi-Jiang Chen, MD, PhD, Center for Reproductive Medicine, Shandong University, No. 157 Jingliu Road, Jinan 250001, China. E-mail: or
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A novel DNA-binding motif in prostate tumor overexpressed-1 (PTOV1) required for the expression of ALDH1A1 and CCNG2 in cancer cells. Cancer Lett 2019; 452:158-167. [PMID: 30922918 DOI: 10.1016/j.canlet.2019.03.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Revised: 03/01/2019] [Accepted: 03/08/2019] [Indexed: 12/26/2022]
Abstract
PTOV1 is a transcription and translation regulator and a promoter of cancer progression. Its overexpression in prostate cancer induces transcription of drug resistance and self-renewal genes, and docetaxel resistance. Here we studied PTOV1 ability to directly activate the transcription of ALDH1A1 and CCNG2 by binding to specific promoter sequences. Chromatin immunoprecipitation and electrophoretic mobility shift assays identified a DNA-binding motif inside the PTOV-A domain with similarities to known AT-hooks that specifically interacts with ALDH1A1 and CCNG2 promoters. Mutation of this AT-hook-like sequence significantly decreased the expression of ALDH1A1 and CCNG2 promoted by PTOV1. Immunohistochemistry revealed the association of PTOV1 with mitotic chromosomes in high grade prostate, colon, bladder, and breast carcinomas. Overexpression of PTOV1, ALDH1A1, and CCNG2 significantly correlated with poor prognosis in prostate carcinomas and with shorter relapse-free survival in colon carcinoma. The previously described interaction with translation complexes and its direct binding to ALDH1A1 and CCNG2 promoters found here reveal the PTOV1 capacity to modulate the expression of critical genes at multiple levels in aggressive cancers. Remarkably, the AT-hook motifs in PTOV1 open possibilities for selective targeting its nuclear and/or cytoplasmic activities.
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Nupr1 regulates palmitate-induced apoptosis in human articular chondrocytes. Biosci Rep 2019; 39:BSR20181473. [PMID: 30674641 PMCID: PMC6379229 DOI: 10.1042/bsr20181473] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Revised: 01/04/2019] [Accepted: 01/09/2019] [Indexed: 12/18/2022] Open
Abstract
Obesity, a major risk factor for the development of osteoarthritis (OA), is associated with increased circulating levels of free fatty acids (FFA). However, the role of these FFAs in OA pathophysiology is not clearly understood. In the present study, we found that palmitate treatment of human primary articular chondrocytes increased the expression of ER stress markers [activating transcription factor 4 (ATF4), C/EBP homologous protein (CHOP)] and apoptosis markers [cytochrome c and cleaved caspase-3 (CC3)]. Palmitate treatment also increased the expression of Nuclear protein 1 (Nupr1) and tribbles related protein 3 (TRB3), which are known negative regulators of cell survival pathways. Knockdown of Nupr1 or CHOP expression inhibited palmitate mediated increased expression of TRB3 and CC3, indicating that Nupr1 and CHOP cooperate to regulate cell survival and apoptotic pathways in human chondrocytes. Nupr1 knockdown had no effect on CHOP expression whereas CHOP knockdown abolished the palmitate-mediated Nupr1 expression, indicating that CHOP is functional upstream to Nupr1 in this pathway. Moreover, overexpression of Nupr1 markedly increased the basal expression of pro-apoptotic molecules, including cytochrome c and CC3. Taken together, our study demonstrates that Nupr1 plays a crucial role in palmitate-induced apoptosis in human chondrocytes and Nupr1 as a potential novel drug target for the treatment of OA.
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Cheng X, Tang F, Hu X, Li H, Li M, Fu Y, Yan L, Li Z, Gou P, Su N, Gong C, He W, Xiang R, Bu D, Shen Y. Two Chinese Xia-Gibbs syndrome patients with partial growth hormone deficiency. Mol Genet Genomic Med 2019; 7:e00596. [PMID: 30729726 PMCID: PMC6465669 DOI: 10.1002/mgg3.596] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 12/16/2018] [Accepted: 01/04/2019] [Indexed: 12/20/2022] Open
Abstract
Background Heterozygous mutations in the AT‐hook DNA‐binding motif containing one (AHDC1, OMIM * 615790) gene cause an autosomal dominant multisystem developmental disorder known as Xia‐Gibbs syndrome (OMIM #615829). Xia‐Gibbs syndrome typically presented with global developmental delay, hypotonia, obstructive sleep apnea, seizures, delayed myelination, micrognathia, and other mild dysmorphic features. Methods Description of the clinical materials of two Chinese boys who were diagnosed with Xia‐Gibbs syndrome based on clinical presentations and next generation sequencing. Review of clinical features and AHDC1 mutations in previously reported Xia‐Gibbs syndrome patients together with our two new patients. Results The Xia‐Gibbs syndrome patients exhibited short stature, hypotonia, global developmental delay, speech delay, simian crease, and mild dysmorphic features. Next generation sequencing revealed de novo heterozygous variants in AHDC1 gene. In addition, laboratory test revealed partial growth hormone deficiency. Both patients underwent growth hormone replacement therapy for 24 and 9 months, respectively, and exhibited good response to the treatment. Conclusion This is the first report of Xia‐Gibbs syndrome patients to be treated with growth hormone. Review of previously reported Xia‐Gibbs syndrome patient indicated that short stature is a frequent feature of this condition, but its underlying cause needs to be further investigated.
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Affiliation(s)
- Xinran Cheng
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Fang Tang
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Xuyun Hu
- Genetic and Metabolic Central Laboratory, Birth Defect Prevention Research Institute, Maternal and Child Health Hospital, Children's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Hongduo Li
- Genetic and Metabolic Central Laboratory, Birth Defect Prevention Research Institute, Maternal and Child Health Hospital, Children's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Mengting Li
- Genetic and Metabolic Central Laboratory, Birth Defect Prevention Research Institute, Maternal and Child Health Hospital, Children's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Yiyong Fu
- Neonatal Intensive Care Unit, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Li Yan
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Zhonghui Li
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Peng Gou
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Na Su
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Chunzhu Gong
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Weilan He
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Rong Xiang
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Dongmei Bu
- Department of Pediatric Endocrinology and Genetic Metabolism, Chengdu Women's and Children's Central Hospital, Chengdu, China
| | - Yiping Shen
- Genetic and Metabolic Central Laboratory, Birth Defect Prevention Research Institute, Maternal and Child Health Hospital, Children's Hospital of Guangxi Zhuang Autonomous Region, Nanning, China.,Department of Medical Genetics and Molecular Diagnostic Laboratory, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.,Division of Genetics and Genomics, Boston Children's Hospital, Boston, Massachusetts.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
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Abstract
Each genomic locus in a eukaryotic cell has a distinct average time of replication during S phase that depends on the spatial and temporal pattern of replication initiation events. Replication timing can affect genomic integrity because late replication is associated with an increased mutation rate. For most eukaryotes, the features of the genome that specify the location and timing of initiation events are unknown. To investigate these features for the fission yeast, Schizosaccharomyces pombe, we developed an integrative model to analyze large single-molecule and global genomic datasets. The model provides an accurate description of the complex dynamics of S. pombe DNA replication at high resolution. We present evidence that there are many more potential initiation sites in the S. pombe genome than previously identified and that the distribution of these sites is primarily determined by two factors: the sequence preferences of the origin recognition complex (ORC), and the interference of transcription with the assembly or stability of prereplication complexes (pre-RCs). We suggest that in addition to directly interfering with initiation, transcription has driven the evolution of the binding properties of ORC in S. pombe and other eukaryotic species to target pre-RC assembly to regions of the genome that are less likely to be transcribed.
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69
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Gao G, Liu C, Jain S, Li D, Wang H, Zhao Y, Liu J. Potential use of aptamers for diagnosis and treatment of pancreatic cancer. J Drug Target 2019; 27:853-865. [PMID: 30596288 DOI: 10.1080/1061186x.2018.1564924] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Pancreatic cancer (PC) is highly malignant with a low 5-year survival rate. PC currently does not have good early diagnostic markers and responses poorly to chemotherapeutic drugs. The search for better biomarkers and developing more effective chemotherapy are important ways to improve the healthcare of PC patients. Aptamers are single-stranded nucleic acids with high binding affinity and specificity to target molecules. Many aptamers against different forms of cancer including PC have been selected for both diagnostic and therapeutic use. Aptamers can work as ligands to distinguish tumour cells from normal cells. Using cells as selection targets, the obtained aptamers have been used to discover new cancer biomarkers after identification of the binding target. Aptamers have been shown to have antagonists effect on cancer cell proliferation, apoptosis, and metastasis. In addition, aptamers have been used as carriers to deliver therapeutic agents to selectively kill PC cells. This review summarises the potential use of aptamers in the diagnosis and treatment of PC.
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Affiliation(s)
- Ge Gao
- a Faculty of Laboratory Medicine , Xiangya Medical College, Central South University , Changsha , China.,b Department of Clinical Laboratory , Third Xiangya Hospital, Central South University , Changsha , China
| | - Can Liu
- a Faculty of Laboratory Medicine , Xiangya Medical College, Central South University , Changsha , China.,b Department of Clinical Laboratory , Third Xiangya Hospital, Central South University , Changsha , China
| | - Sona Jain
- c Department of Chemistry , Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo , Canada
| | - Dai Li
- c Department of Chemistry , Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo , Canada.,d Department of Pharmacology , Xiangya Hospital, Central South University , Changsha , China
| | - Hai Wang
- a Faculty of Laboratory Medicine , Xiangya Medical College, Central South University , Changsha , China.,b Department of Clinical Laboratory , Third Xiangya Hospital, Central South University , Changsha , China
| | - Yongxin Zhao
- a Faculty of Laboratory Medicine , Xiangya Medical College, Central South University , Changsha , China.,b Department of Clinical Laboratory , Third Xiangya Hospital, Central South University , Changsha , China
| | - Juewen Liu
- c Department of Chemistry , Waterloo Institute for Nanotechnology, University of Waterloo , Waterloo , Canada
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Tanabe K, Awane R, Shoda T, Yamazoe K, Inoue YH. Mutations in mxc Tumor-Suppressor Gene Induce Chromosome Instability in Drosophila Male Meiosis. Cell Struct Funct 2019; 44:121-135. [DOI: 10.1247/csf.19022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Karin Tanabe
- Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology
| | - Rie Awane
- Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology
| | - Tsuyoshi Shoda
- Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology
| | - Kanta Yamazoe
- Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology
| | - Yoshihiro H. Inoue
- Department of Insect Biomedical Research, Center for Advanced Insect Research Promotion, Kyoto Institute of Technology
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71
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Hombach-Klonisch S, Kalantari F, Medapati MR, Natarajan S, Krishnan SN, Kumar-Kanojia A, Thanasupawat T, Begum F, Xu FY, Hatch GM, Los M, Klonisch T. HMGA2 as a functional antagonist of PARP1 inhibitors in tumor cells. Mol Oncol 2018; 13:153-170. [PMID: 30289618 PMCID: PMC6360374 DOI: 10.1002/1878-0261.12390] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 09/19/2018] [Accepted: 09/20/2018] [Indexed: 01/05/2023] Open
Abstract
Poly(ADP‐ribose) polymerase 1 inhibitors alone or in combination with DNA damaging agents are promising clinical drugs in the treatment of cancer. However, there is a need to understand the molecular mechanisms of resistance to PARP1 inhibitors. Expression of HMGA2 in cancer is associated with poor prognosis for patients. Here, we investigated the novel relationship between HMGA2 and PARP1 in DNA damage‐induced PARP1 activity. We used human triple‐negative breast cancer and fibrosarcoma cell lines to demonstrate that HMGA2 colocalizes and interacts with PARP1. High cellular HMGA2 levels correlated with increased DNA damage‐induced PARP1 activity, which was dependent on functional DNA‐binding AT‐hook domains of HMGA2. HMGA2 inhibited PARP1 trapping to DNA and counteracted the cytotoxic effect of PARP inhibitors. Consequently, HMGA2 decreased caspase 3/7 induction and increased cell survival upon treatment with the alkylating methyl methanesulfonate alone or in combination with the PARP inhibitor AZD2281 (olaparib). HMGA2 increased mitochondrial oxygen consumption rate and spare respiratory capacity and increased NAMPT levels, suggesting metabolic support for enhanced PARP1 activity upon DNA damage. Our data showed that expression of HMGA2 in cancer cells reduces sensitivity to PARP inhibitors and suggests that targeting HMGA2 in combination with PARP inhibition may be a promising new therapeutic approach.
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Affiliation(s)
- Sabine Hombach-Klonisch
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Forouh Kalantari
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Manoj Reddy Medapati
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Suchitra Natarajan
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Sai Nivedita Krishnan
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Aditya Kumar-Kanojia
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Thatchawan Thanasupawat
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Farhana Begum
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Fred Y Xu
- Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Grant M Hatch
- Department of Pharmacology & Therapeutics, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada.,Department of Biochemistry and Medical Genetics, DREAM, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Marek Los
- Department of Małopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland
| | - Thomas Klonisch
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada.,Department of Surgery, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada.,Department of Medical Microbiology & Infectious Diseases, Rady Faculty of Health Sciences, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
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Garabedian A, Bolufer A, Leng F, Fernandez-Lima F. Peptide Sequence Influence on the Conformational Dynamics and DNA binding of the Intrinsically Disordered AT-Hook 3 Peptide. Sci Rep 2018; 8:10783. [PMID: 30018295 PMCID: PMC6050235 DOI: 10.1038/s41598-018-28956-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/28/2018] [Indexed: 11/09/2022] Open
Abstract
The intrinsically disordered ATHP3 was studied at native conditions and in complex with DNA using single amino acid substitutions and high-resolution ion mobility spectrometry coupled to mass spectrometry (trapped IMS-MS). Results showed that ATHP3 can exist in multiple conformations at native conditions (at least 10 conformers were separated), with a variety of proline cis/trans orientations, side chain orientations and protonation sites. When in complex with AT rich DNA hairpins, the -RGRP- core is essential for stabilizing the ATHP3: DNA complex. In particular, the arginine in the sixth position plays an important role during binding to AT-rich regions of hairpin DNA, in good agreement with previous NMR and X-ray data. Mobility based correlation matrices are proposed as a way to reveal differences in structural motifs across the peptide mutants based on the conformational space and relative conformer abundance.
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Affiliation(s)
- Alyssa Garabedian
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199, United States
| | - Alexander Bolufer
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199, United States
| | - Fenfei Leng
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199, United States.,Biomolecular Sciences Institute, Florida International University, Miami, Florida, 33199, United States
| | - Francisco Fernandez-Lima
- Department of Chemistry and Biochemistry, Florida International University, Miami, Florida, 33199, United States. .,Biomolecular Sciences Institute, Florida International University, Miami, Florida, 33199, United States.
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Orłowski M, Popławska K, Pieprzyk J, Szczygieł-Sommer A, Więch A, Zarębski M, Tarczewska A, Dobrucki J, Ożyhar A. Molecular determinants of Drosophila immunophilin FKBP39 nuclear localization. Biol Chem 2018; 399:467-484. [PMID: 29337690 DOI: 10.1515/hsz-2017-0251] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 01/04/2018] [Indexed: 12/27/2022]
Abstract
FK506-binding proteins (FKBPs) belong to a distinct class of immunophilins that interact with immunosuppressants. They use their peptidyl-prolyl isomerase (PPIase) activity to catalyze the cis-trans conversion of prolyl bonds in proteins during protein-folding events. FKBPs also act as a unique group of chaperones. The Drosophila melanogaster peptidyl-prolyl cis-trans isomerase FK506-binding protein of 39 kDa (FKBP39) is thought to act as a transcriptional modulator of gene expression in 20-hydroxyecdysone and juvenile hormone signal transduction. The aim of this study was to analyze the molecular determinants responsible for the subcellular distribution of an FKBP39-yellow fluorescent protein (YFP) fusion construct (YFP-FKBP39). We found that YFP-FKBP39 was predominantly nucleolar. To identify the nuclear localization signal (NLS), a series of YFP-tagged FKBP39 deletion mutants were prepared and examined in vivo. The identified NLS signal is located in a basic domain. Detailed mutagenesis studies revealed that residues K188 and K191 are crucial for the nuclear targeting of FKBP39 and its nucleoplasmin-like (NPL) domain contains the sequence that controls the nucleolar-specific translocation of the protein. These results show that FKBP39 possesses a specific NLS in close proximity to a putative helix-turn-helix (HTH) motif and FKBP39 may bind DNA in vivo and in vitro.
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Affiliation(s)
- Marek Orłowski
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Katarzyna Popławska
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Joanna Pieprzyk
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Aleksandra Szczygieł-Sommer
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Anna Więch
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Mirosław Zarębski
- Department of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Aneta Tarczewska
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
| | - Jurek Dobrucki
- Department of Cell Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 30-387 Kraków, Poland
| | - Andrzej Ożyhar
- Department of Biochemistry, Faculty of Chemistry, Wrocław University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
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74
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Jagannathan M, Yamashita YM. Function of Junk: Pericentromeric Satellite DNA in Chromosome Maintenance. COLD SPRING HARBOR SYMPOSIA ON QUANTITATIVE BIOLOGY 2018; 82:319-327. [PMID: 29610245 DOI: 10.1101/sqb.2017.82.034504] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Satellite DNAs are simple tandem repeats that exist at centromeric and pericentromeric regions on eukaryotic chromosomes. Unlike the centromeric satellite DNA that comprises the vast majority of natural centromeres, function(s) for the much more abundant pericentromeric satellite repeats are poorly understood. In fact, the lack of coding potential allied with rapid divergence of repeat sequences across eukaryotes has led to their dismissal as "junk DNA" or "selfish parasites." Although implicated in various biological processes, a conserved function for pericentromeric satellite DNA remains unidentified. We have addressed the role of satellite DNA through studying chromocenters, a cytological aggregation of pericentromeric satellite DNA from multiple chromosomes into DNA-dense nuclear foci. We have shown that multivalent satellite DNA-binding proteins cross-link pericentromeric satellite DNA on chromosomes into chromocenters. Disruption of chromocenters results in the formation of micronuclei, which arise by budding off the nucleus during interphase. We propose a model that satellite DNAs are critical chromosome elements that are recognized by satellite DNA-binding proteins and incorporated into chromocenters. We suggest that chromocenters function to preserve the entire chromosomal complement in a single nucleus, a fundamental and unquestioned feature of eukaryotic genomes. We speculate that the rapid divergence of satellite DNA sequences between closely related species results in discordant chromocenter function and may underlie speciation and hybrid incompatibility.
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Affiliation(s)
- Madhav Jagannathan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109
| | - Yukiko M Yamashita
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109.,Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109.,Howard Hughes Medical Institute, University of Michigan, Ann Arbor, Michigan 48109
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75
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Ejlersen M, Christensen NJ, Sørensen KK, Jensen KJ, Wengel J, Lou C. Synergy of Two Highly Specific Biomolecular Recognition Events: Aligning an AT-Hook Peptide in DNA Minor Grooves via Covalent Conjugation to 2'-Amino-LNA. Bioconjug Chem 2018; 29:1025-1029. [PMID: 29505242 DOI: 10.1021/acs.bioconjchem.8b00101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two highly specific biomolecular recognition events, nucleic acid duplex hybridization and DNA-peptide recognition in the minor groove, were coalesced in a miniature ensemble for the first time by covalently attaching a natural AT-hook peptide motif to nucleic acid duplexes via a 2'-amino-LNA scaffold. A combination of molecular dynamics simulations and ultraviolet thermal denaturation studies revealed high sequence-specific affinity of the peptide-oligonucleotide conjugates (POCs) when binding to complementary DNA strands, leveraging the bioinformation encrypted in the minor groove of DNA duplexes. The significant cooperative DNA duplex stabilization may pave the way toward further development of POCs with enhanced affinity and selectivity toward target sequences carrying peptide-binding genetic islands.
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Affiliation(s)
- Maria Ejlersen
- Biomolecular Nanoscale Engineering Center, Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , 5230 Odense M , Denmark
| | - Niels Johan Christensen
- Biomolecular Nanoscale Engineering Center, Department of Chemistry , University of Copenhagen , Thorvaldsensvej 40 , 1871 Frederiksberg , Denmark
| | - Kasper K Sørensen
- Biomolecular Nanoscale Engineering Center, Department of Chemistry , University of Copenhagen , Thorvaldsensvej 40 , 1871 Frederiksberg , Denmark
| | - Knud J Jensen
- Biomolecular Nanoscale Engineering Center, Department of Chemistry , University of Copenhagen , Thorvaldsensvej 40 , 1871 Frederiksberg , Denmark
| | - Jesper Wengel
- Biomolecular Nanoscale Engineering Center, Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , 5230 Odense M , Denmark
| | - Chenguang Lou
- Biomolecular Nanoscale Engineering Center, Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , 5230 Odense M , Denmark
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76
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Sheikh TI, Harripaul R, Ayub M, Vincent JB. MeCP2 AT-Hook1 mutations in patients with intellectual disability and/or schizophrenia disrupt DNA binding and chromatin compaction in vitro. Hum Mutat 2018; 39:717-728. [DOI: 10.1002/humu.23409] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Revised: 01/10/2018] [Accepted: 02/07/2018] [Indexed: 01/29/2023]
Affiliation(s)
- Taimoor I. Sheikh
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
| | - Ricardo Harripaul
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
| | - Muhammad Ayub
- Lahore Institute of Research & Development; Lahore Pakistan
- Department of Psychiatry; Queen's University; Kingston Ontario Canada
| | - John B. Vincent
- Molecular Neuropsychiatry & Development (MiND) Lab; Campbell Family Mental Health Research Institute; Centre for Addiction and Mental Health; Toronto Ontario Canada
- Institute of Medical Science; University of Toronto; Toronto Ontario Canada
- Department of Psychiatry; University of Toronto; Toronto Ontario Canada
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77
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Zhang H, Yang J, Walters MS, Staudt MR, Strulovici-Barel Y, Salit J, Mezey JG, Leopold PL, Crystal RG. Mandatory role of HMGA1 in human airway epithelial normal differentiation and post-injury regeneration. Oncotarget 2018; 9:14324-14337. [PMID: 29581847 PMCID: PMC5865673 DOI: 10.18632/oncotarget.24511] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Accepted: 01/20/2018] [Indexed: 12/11/2022] Open
Abstract
Due to high levels of expression in aggressive tumors, high mobility group AT-hook 1 (HMGA1) has recently attracted attention as a potential anti-tumor target. However, HMGA1 is also expressed in normal somatic progenitor cells, raising the question: how might systemic anti-HMGA1 therapies affect the structure and function of normal tissue differentiation? In the present study, RNA sequencing data demonstrated HMGA1 is highly expressed in human airway basal stem/progenitor cells (BC), but decreases with BC differentiation in air-liquid interface cultures (ALI). BC collected from nonsmokers, healthy smokers, and smokers with chronic obstructive pulmonary disease (COPD) displayed a range of HMGA1 expression levels. Low initial expression levels of HMGA1 in BC were associated with decreased ability to maintain a differentiated ALI epithelium. HMGA1 down-regulation in BC diminished BC proliferation, suppressed gene expression related to normal proliferation and differentiation, decreased airway epithelial resistance, suppressed junctional and cell polarity gene expression, and delayed wound closure of airway epithelium following injury. Furthermore, silencing of HMGA1 in airway BC in ALI increased the expression of genes associated with airway remodeling in COPD including squamous, epithelial-mesenchymal transition (EMT), and inflammatory genes. Together, the data suggests HMGA1 plays a central role in normal airway differentiation, and thus caution should be used to monitor airway epithelial structure and function in the context of systemic HMGA1-targeted therapies.
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Affiliation(s)
- Haijun Zhang
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Jing Yang
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Matthew S Walters
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Michelle R Staudt
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | | | - Jacqueline Salit
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Jason G Mezey
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA.,Department of Biological Statistics and Computational Biology, Cornell University, Ithaca, NY, USA
| | - Philip L Leopold
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
| | - Ronald G Crystal
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY, USA
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78
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Hassan F, Ni S, Arnett TC, McKell MC, Kennedy MA. Adenovirus-Mediated Delivery of Decoy Hyper Binding Sites Targeting Oncogenic HMGA1 Reduces Pancreatic and Liver Cancer Cell Viability. MOLECULAR THERAPY-ONCOLYTICS 2018; 8:52-61. [PMID: 29511732 PMCID: PMC5832671 DOI: 10.1016/j.omto.2018.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 01/17/2018] [Indexed: 11/23/2022]
Abstract
High mobility group AT-hook 1 (HMGA1) protein is an oncogenic architectural transcription factor that plays an essential role in early development, but it is also implicated in many human cancers. Elevated levels of HMGA1 in cancer cells cause misregulation of gene expression and are associated with increased cancer cell proliferation and increased chemotherapy resistance. We have devised a strategy of using engineered viruses to deliver decoy hyper binding sites for HMGA1 to the nucleus of cancer cells with the goal of sequestering excess HMGA1 at the decoy hyper binding sites due to binding competition. Sequestration of excess HMGA1 at the decoy binding sites is intended to reduce HMGA1 binding at the naturally occurring genomic HMGA1 binding sites, which should result in normalized gene expression and restored sensitivity to chemotherapy. As proof of principle, we engineered the replication defective adenovirus serotype 5 genome to contain hyper binding sites for HMGA1 composed of six copies of an individual HMGA1 binding site, referred to as HMGA-6. A 70%–80% reduction in cell viability and increased sensitivity to gemcitabine was observed in five different pancreatic and liver cancer cell lines 72 hr after infection with replication defective engineered adenovirus serotype 5 virus containing the HMGA-6 decoy hyper binding sites. The decoy hyper binding site strategy should be general for targeting overexpression of any double-stranded DNA-binding oncogenic transcription factor responsible for cancer cell proliferation.
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Affiliation(s)
- Faizule Hassan
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Shuisong Ni
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Tyler C Arnett
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Melanie C McKell
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
| | - Michael A Kennedy
- Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056, USA
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79
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Nanoscale Assembly of High-Mobility Group AT-Hook 2 Protein with DNA Replication Fork. Biophys J 2018; 113:2609-2620. [PMID: 29262356 DOI: 10.1016/j.bpj.2017.10.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 08/24/2017] [Accepted: 10/12/2017] [Indexed: 01/31/2023] Open
Abstract
High mobility group AT-hook 2 (HMGA2) protein is composed of three AT-hook domains. HMGA2 expresses at high levels in both embryonic stem cells and cancer cells, where it interacts with and stabilizes replication forks (RFs), resulting in elevated cell proliferation rates. In this study, we demonstrated that HMGA2 knockdown reduces cell proliferation. To understand the features required for interaction between HMGA2 and RFs, we studied the solution structure of HMGA2, free and in complex with RFs, using an integrated host of biophysical techniques. Circular dichroism and NMR experiments confirmed the disordered state of unbound HMGA2. Dynamic light scattering and sedimentation velocity experiments demonstrated that HMGA2 and RF are monodisperse in solution, and form an equimolar complex. Small-angle x-ray scattering studies revealed that HMGA2 binds in a side-by-side orientation to RF where 3 AT-hooks act as a clamp to wrap around a distorted RF. Thus, our data provide insights into how HMGA2 interacts with stalled RFs and the function of the process.
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80
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Boga S, Bouzada D, García Peña D, Vázquez López M, Vázquez ME. Sequence-Specific DNA Recognition with Designed Peptides. European J Org Chem 2017. [DOI: 10.1002/ejoc.201700988] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Sonia Boga
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica; Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
| | - David Bouzada
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica; Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
| | - Diego García Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica; Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
| | - Miguel Vázquez López
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Inorgánica; Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
| | - M. Eugenio Vázquez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica; Universidade de Santiago de Compostela; 15782 Santiago de Compostela Spain
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81
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McQuaid ME, Pinder JB, Arumuggam N, Lacoste JSC, Chew JSK, Dobson MJ. The yeast 2-μm plasmid Raf protein contributes to plasmid inheritance by stabilizing the Rep1 and Rep2 partitioning proteins. Nucleic Acids Res 2017; 45:10518-10533. [PMID: 29048592 PMCID: PMC5737570 DOI: 10.1093/nar/gkx703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 08/01/2017] [Indexed: 12/26/2022] Open
Abstract
The yeast 2-μm plasmid is a remarkable genetic parasite, managing efficient maintenance at high-copy number with minimal impact on the host. Equal partitioning of the plasmid upon host cell division requires plasmid proteins Rep1 and Rep2 and the plasmid STB locus. The Rep proteins and the plasmid-encoded Raf protein also regulate plasmid gene transcription. In this study, protein interaction assays, sequence analyses and mutational approaches were used to identify domains and residues in Rep2 and Raf required for association with Rep1 and Rep2 and to delineate the Rep2 DNA-binding domain. Rep2 and Raf displayed similarities in interactions with Rep1 and Rep2, in having Rep1 promote their STB association in vivo, and in stabilizing Rep protein levels. Rep2 mutants impaired for self-association were competent for transcriptional repression while those deficient for Rep1 association were not. Surprisingly, Rep2 mutants impaired for either Rep1 interaction or self-association were able to maintain efficient plasmid inheritance provided Raf was present and competent for Rep protein interaction. Our findings provide insight into the Rep protein complexes required for partitioning and transcriptional repression, and suggest that in addition to its transcriptional function, Raf stabilization of Rep partitioning proteins contributes to the remarkable persistence of the 2-μm plasmid.
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Affiliation(s)
- Mary E McQuaid
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jordan B Pinder
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Niroshaathevi Arumuggam
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jessica S C Lacoste
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Joyce S K Chew
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Melanie J Dobson
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
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82
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Xiao H, Wang F, Wisniewski J, Shaytan AK, Ghirlando R, FitzGerald PC, Huang Y, Wei D, Li S, Landsman D, Panchenko AR, Wu C. Molecular basis of CENP-C association with the CENP-A nucleosome at yeast centromeres. Genes Dev 2017; 31:1958-1972. [PMID: 29074736 PMCID: PMC5710141 DOI: 10.1101/gad.304782.117] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/05/2017] [Indexed: 12/16/2022]
Abstract
Histone CENP-A-containing nucleosomes play an important role in nucleating kinetochores at centromeres for chromosome segregation. However, the molecular mechanisms by which CENP-A nucleosomes engage with kinetochore proteins are not well understood. Here, we report the finding of a new function for the budding yeast Cse4/CENP-A histone-fold domain interacting with inner kinetochore protein Mif2/CENP-C. Strikingly, we also discovered that AT-rich centromere DNA has an important role for Mif2 recruitment. Mif2 contacts one side of the nucleosome dyad, engaging with both Cse4 residues and AT-rich nucleosomal DNA. Both interactions are directed by a contiguous DNA- and histone-binding domain (DHBD) harboring the conserved CENP-C motif, an AT hook, and RK clusters (clusters enriched for arginine-lysine residues). Human CENP-C has two related DHBDs that bind preferentially to DNA sequences of higher AT content. Our findings suggest that a DNA composition-based mechanism together with residues characteristic for the CENP-A histone variant contribute to the specification of centromere identity.
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Affiliation(s)
- Hua Xiao
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Feng Wang
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Jan Wisniewski
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
| | - Alexey K Shaytan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Peter C FitzGerald
- Genome Analysis Unit, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Yingzi Huang
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Debbie Wei
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Shipeng Li
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - David Landsman
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Anna R Panchenko
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Carl Wu
- Laboratory of Biochemistry and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia 20147, USA
- Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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83
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Shur KV, Maslov DA, Mikheecheva NE, Akimova NI, Bekker OB, Danilenko VN. The intrinsic antibiotic resistance to β-lactams, macrolides, and fluoroquinolones of mycobacteria is mediated by the whiB7 and tap genes. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417080087] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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84
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Sun X, Xu M, Liu H, Ming K. MicroRNA-219 is downregulated in non-small cell lung cancer and inhibits cell growth and metastasis by targeting HMGA2. Mol Med Rep 2017; 16:3557-3564. [PMID: 28714014 DOI: 10.3892/mmr.2017.7000] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 04/21/2017] [Indexed: 11/05/2022] Open
Abstract
Lung cancer is the most commonly diagnosed cancer and the leading cause of cancer-associated mortality worldwide. Non-small cell lung cancer (NSCLC) is the predominant type of lung cancer, and accounts for ~85% of all lung cancer cases. An increasing number of studies suggest that microRNAs (miRs) may be involved in the regulation of NSCLC carcinogenesis and progression. However, the expression and function of miRNA-219 in NSCLC, and its underlying mechanisms of action, remain unknown. In the present study, miR-219 expression in NSCLC tissues and cell lines was determined using reverse transcription-quantitative polymerase chain reaction. Following transfection with miR-219 mimics, the effects of miR-219 overexpression on NSCLC cell proliferation, migration and invasion were examined. Furthermore, the miR-219 target in NSCLC was investigated. miR-219 was observed to be downregulated in NSCLC tissues and NSCLC cell lines. In addition, miR-219 was demonstrated to function as a tumor suppressor in NSCLC, through inhibiting cell proliferation, migration and invasion in vitro. Furthermore, high mobility group AT-hook 2 (HMGA2) was identified to be a direct target of miR-219 in NSCLC, and downregulation of HMGA2 suppressed NSCLC cell proliferation, migration and invasion in vitro. HMGA2 expression was upregulated in NSCLC tissues, and was inversely correlated with miR-219 expression. In conclusion, miR-219 functions as a tumor suppressor and may be important in inhibiting the growth and metastasis of NSCLC cells via directly targeting HMGA2. Therefore, miR-219 may present a potential novel therapeutic target for NSCLC.
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Affiliation(s)
- Xiaoping Sun
- Department of Emergency, Yidu Central Hospital of Weifang, Weifang Medical University, Weifang, Shandong 262500, P.R. China
| | - Min Xu
- Department of Emergency, Yidu Central Hospital of Weifang, Weifang Medical University, Weifang, Shandong 262500, P.R. China
| | - Haiyan Liu
- Department of Emergency, Yidu Central Hospital of Weifang, Weifang Medical University, Weifang, Shandong 262500, P.R. China
| | - Kunxiu Ming
- Department of Emergency Medicine, Weifang People's Hospital, Weifang, Shandong 261000, P.R. China
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85
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Oncofetal HMGA2 effectively curbs unconstrained (+) and (-) DNA supercoiling. Sci Rep 2017; 7:8440. [PMID: 28814752 PMCID: PMC5559611 DOI: 10.1038/s41598-017-09104-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Accepted: 07/20/2017] [Indexed: 02/06/2023] Open
Abstract
HMGA2 belongs to the family of the high mobility group (HMG) proteins. It binds DNA via three AT-hook domains to the minor groove of adenine-thymine (AT) rich DNA. Recently, a new function of HMGA2 as a replication fork chaperone that protects stem and cancer cells from replication fork collapse induced by chemotherapeutic agents was uncovered, suggesting a previously uncharacterized binding at replication forks. In this study, we examined HMGA2 binding to four DNA structures relevant to replication forks, namely ds DNA, ss DNA, forked DNA and supercoiled DNA plectonemes. We detected HMGA2 binding to supercoiled DNA at the lowest concentration and this binding mode transiently stabilizes the supercoiled plectonemes against relaxation by type I topoisomerase. Together, these findings suggest a plausible mechanism how fork regression and collapse are attenuated by HMGA2 during replication stress, i.e. through transient stabilization of positively supercoiled plectonemes in the parental duplex.
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86
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HMGA2, a driver of inflammation, is associated with hypermethylation in acute liver injury. Toxicol Appl Pharmacol 2017; 328:34-45. [DOI: 10.1016/j.taap.2017.05.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Revised: 04/23/2017] [Accepted: 05/08/2017] [Indexed: 12/11/2022]
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87
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Volk DE, Lokesh GLR. Development of Phosphorothioate DNA and DNA Thioaptamers. Biomedicines 2017; 5:E41. [PMID: 28703779 PMCID: PMC5618299 DOI: 10.3390/biomedicines5030041] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 07/03/2017] [Accepted: 07/11/2017] [Indexed: 02/07/2023] Open
Abstract
Nucleic acid aptamers are short RNA- or DNA-based affinity reagents typically selected from combinatorial libraries to bind to a specific target such as a protein, a small molecule, whole cells or even animals. Aptamers have utility in the development of diagnostic, imaging and therapeutic applications due to their size, physico-chemical nature and ease of synthesis and modification to suit the application. A variety of oligonucleotide modifications have been used to enhance the stability of aptamers from nuclease degradation in vivo. The non-bridging oxygen atoms of the phosphodiester backbones of RNA and DNA aptamers can be substituted with one or two sulfur atoms, resulting in thioaptamers with phosphorothioate or phosphorodithioate linkages, respectively. Such thioaptamers are known to have increased binding affinity towards their target, as well as enhanced resistance to nuclease degradation. In this review, we discuss the development of phosphorothioate chemistry and thioaptamers, with a brief review of selection methods.
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Affiliation(s)
- David E Volk
- McGovern Medical School, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas Health Science Center, Houston, TX 77030, USA.
| | - Ganesh L R Lokesh
- McGovern Medical School, Brown Foundation Institute of Molecular Medicine for the Prevention of Human Diseases, University of Texas Health Science Center, Houston, TX 77030, USA.
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88
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Clinicopathological and prognostic significance of HMGA2 overexpression in gastric cancer: a meta-analysis. Oncotarget 2017; 8:100478-100489. [PMID: 29245994 PMCID: PMC5725036 DOI: 10.18632/oncotarget.19001] [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: 12/14/2016] [Accepted: 06/18/2017] [Indexed: 12/29/2022] Open
Abstract
Background High mobility group protein A2 (HMGA2) overexpression has been reported to be closely related to tumor progression [1-4] and indicate significantly worse overall survival in gastric cancer [5-8]. However, a final consensus regarding this issue has not yet been reached. Thus, we conducted a meta-analysis to evaluate the association between HMGA2 expression and prognosis of gastric cancer patients. Methods The Cochrane Library, Embase, PubMed, Web of Science and China Biology Medicine databases were searched to identify eligible literature published prior to September 2016. In the included studies, the level of HMGA2 amplification was evaluated by immunohistochemistry. We performed a meta-analysis, and pooled relative risk (RRs), hazard ratio (HRs), and 95% confidence intervals (CIs) were analyzed using Review Manager 5.3. Results Six studies [5-7, 9-11] involving 712 gastric cancer patients were included and stratified by HMGA2 amplification magnitude. The results of the analysis indicated that higher HMGA2 levels were associated with several clinicopathological parameters and predicted poor prognosis in terms of overall survival (OS). Conclusions The results of the present study indicate that higher HMGA2 levels were significantly associated with TNM stage, lymph node status, vascular invasion, and poor OS in patients with gastric cancer. In conclusion, HMGA2 may serve as a promising prognostic biomarker in gastric cancer.
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89
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Kharrat M, Kamoun Y, Kamoun F, Ellouze E, Maalej M, Fendri-Kriaa N, Ammar-Keskes L, Belghith N, Gargouri A, Triki C, Fakhfakh F. Clinical, Molecular, and Computational Analysis in Patients With a Novel Double Mutation and a New Synonymous Variant in MeCP2: Report of the First Missense Mutation Within the AT-hook1 Cluster in Rett Syndrome. J Child Neurol 2017; 32:694-703. [PMID: 28399682 DOI: 10.1177/0883073817701622] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Rett syndrome is an X-linked neurodevelopmental disorder, primarily caused by MECP2 mutations. In this study, clinical, molecular and bioinformatics analyses were performed in Rett patients to understand the relationship between MECP2 mutation type and the clinical severity. Two double MeCP2 mutations were detected: a novel one (p.G185 V in cis with p.R255X) in P1 and a known one (p.P179 S in cis with p.R255X) in P2. Besides, a novel synonymous mutation (c.807C>T; p.G269G), which could affect mRNA splicing, was identified in P3. The results from clinical severity analysis have shown that P1 was more severely affected than P2 with CSS being 35 and 14, respectively. Therefore, the phenotypic variability in P1 and P2 could be explained by the potential pathogenic effect of the RTT-causing missense mutation p.G185 V in the AT-hook1. In conclusion, clinical, molecular, and in silico investigations in the studied patients have been proven to be substantial for the genotype-phenotype correlation.
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Affiliation(s)
- Marwa Kharrat
- 1 Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, University of Sfax, Sfax, Tunisia.,2 Laboratory of Human Molecular Genetics, Faculty of Medicine, Sfax, Tunisia
| | - Yosra Kamoun
- 3 Laboratory of Molecular Biotechnologie of Eukaryotes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Fatma Kamoun
- 4 Service de Neurologie Infantile, C.H.U. Hédi Chaker de Sfax, Tunisia
| | - Emna Ellouze
- 4 Service de Neurologie Infantile, C.H.U. Hédi Chaker de Sfax, Tunisia
| | - Marwa Maalej
- 2 Laboratory of Human Molecular Genetics, Faculty of Medicine, Sfax, Tunisia
| | - Nourhene Fendri-Kriaa
- 1 Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, University of Sfax, Sfax, Tunisia
| | - Leila Ammar-Keskes
- 2 Laboratory of Human Molecular Genetics, Faculty of Medicine, Sfax, Tunisia
| | - Neila Belghith
- 2 Laboratory of Human Molecular Genetics, Faculty of Medicine, Sfax, Tunisia
| | - Ali Gargouri
- 3 Laboratory of Molecular Biotechnologie of Eukaryotes, Centre of Biotechnology of Sfax, University of Sfax, Sfax, Tunisia
| | - Chahnez Triki
- 4 Service de Neurologie Infantile, C.H.U. Hédi Chaker de Sfax, Tunisia
| | - Faiza Fakhfakh
- 1 Laboratory of Molecular and Functional Genetics, Faculty of Science of Sfax, University of Sfax, Sfax, Tunisia
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90
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Yang Q, Wang X, Tang C, Chen X, He J. H19 promotes the migration and invasion of colon cancer by sponging miR-138 to upregulate the expression of HMGA1. Int J Oncol 2017; 50:1801-1809. [PMID: 28358427 DOI: 10.3892/ijo.2017.3941] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Accepted: 03/09/2017] [Indexed: 11/06/2022] Open
Abstract
Colon cancer is the most common digestive system malignancy, along with high mortality rate, familial transmissibility and hepatic metastasis. Our study investigated the role of long non-coding RNA H19 in colon cancer. We found that H19 was overexpressed in colon cancer tissues and cell lines, the interference of H19 by short hairpin RNA (shRNA) effectively decreased the migration and invasion of colon cancer cells (HT-29 and RKO). Besides, miR-138 was predicted a target of H19, and low expression of miR-138 was found in colon cancer tissues and cells. The silence of H19 strongly increased the expression of miR-138. The decreased level of miR-138 was elevated adding miR-138 mimic in RKO cells transfected with lncRNA-H19. Similarly, the upregulated level of miR-138 was downregulated adding miR-138 inhibitor in RKO cells transfected with H19 shRNA. The luciferase reporter confirmed the targeting reaction between H19 and miR-138. Moreover, the high-mobility group A (HMGA1) protein was predicted as a target of miR-138. HMGA1 was suppressed by H19 shRNA and could be up-regulated by miR-138 inhibitor. The migration and invasion ability of colon cancer was restrained by H19 shRNA and promoted by miR-138 inhibitor. Finally, the in vivo experiment revealed that H19 shRNA strongly reduced the tumor growth and tumor volume. H19 shRNA also inhibited metastasis via suppressing hepatic metastases and the expression of metastasis-related proteins. Taken together, our research indicated an H19-miR138-HMGA1 pathway in regulating the migration and invasion of colon cancer, providing new insight for treatment of colon cancer.
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Affiliation(s)
- Qingqiang Yang
- Department of General Surgery, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Xin Wang
- Department of General Surgery, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Chunyan Tang
- Department of Nursing, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Xuan Chen
- Department of General Surgery, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
| | - Jianjun He
- Department of General Surgery, The Affiliated Hospital, Southwest Medical University, Luzhou, Sichuan 646000, P.R. China
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91
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Uchikura Y, Matsubara K, Muto Y, Matsubara Y, Fujioka T, Matsumoto T, Sugiyama T. Extranuclear Translocation of High-Mobility Group A1 Reduces the Invasion of Extravillous Trophoblasts Involved in the Pathogenesis of Preeclampsia: New Aspect of High-Mobility Group A1. Reprod Sci 2017; 24:1630-1638. [PMID: 28345487 DOI: 10.1177/1933719117697254] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVE High-mobility group A1 (HMGA1) protein is known to express in trophoblast; however, the role of migration has not been reported to date. In this study, we investigated the role of HMGA1 on the pathogenesis of preeclampsia using immortalized human trophoblast cell (HTR-8/SVneo). MATERIALS AND METHODS We investigated HMGA1 expression in cytotrophoblasts derived from our preeclampsia model mouse, the CD40L mouse, using immunofluorescence. Wound healing and transwell migration assays were also performed using HTR-8/SVneo (extravillous trophoblast) cells transfected with DNA or siRNA of HMGA1. The effect of extranuclear translocation of HMGA1 on the migration of extravillous trophoblastic cells was evaluated using deoxycholic acid (DCA). RESULTS HMGA1 was expressed exclusively in the nuclei of trophoblasts derived from control mice; cytoplasmic expression was observed only in CD40L mice with preeclampsia. Furthermore, overexpression of HMGA1 in the nuclei of HTR-8/SVneo cells stimulated cell proliferation and migration. Translocation of nuclear HMGA1 to cytoplasm treated with DCA reduced cell migration. CONCLUSIONS Collectively, these findings demonstrate that proper subcellular localization of HMGA1 is important for its function in trophoblast cells, and suggest that aberrant cytoplasmic expression of HMGA1 contributes to the pathogenesis of preeclampsia through impairment of trophoblast migration.
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Affiliation(s)
- Yuka Uchikura
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
| | - Keiichi Matsubara
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
| | - Yoshifumi Muto
- 2 Bell Research Center, Nagoya University Graduate School of Medicine, Showa-ku, Nagoya, Aichi, Japan
| | - Yuko Matsubara
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
| | - Toru Fujioka
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
| | - Takashi Matsumoto
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
| | - Takashi Sugiyama
- 1 Department of Obstetrics and Gynecology, Ehime University Graduate School of Medicine, Shitsukawa, Toon, Ehime, Japan
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92
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Kwok J, O'Shea M, Hume DA, Lengeling A. Jmjd6, a JmjC Dioxygenase with Many Interaction Partners and Pleiotropic Functions. Front Genet 2017; 8:32. [PMID: 28360925 PMCID: PMC5352680 DOI: 10.3389/fgene.2017.00032] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/27/2017] [Indexed: 12/20/2022] Open
Abstract
Lysyl hydroxylation and arginyl demethylation are post-translational events that are important for many cellular processes. The jumonji domain containing protein 6 (JMJD6) has been reported to catalyze both lysyl hydroxylation and arginyl demethylation on diverse protein substrates. It also interacts directly with RNA. This review summarizes knowledge of JMJD6 functions that have emerged in the last 15 years and considers how a single Jumonji C (JmjC) domain-containing enzyme can target so many different substrates. New links and synergies between the three main proposed functions of Jmjd6 in histone demethylation, promoter proximal pause release of polymerase II and RNA splicing are discussed. The physiological context of the described molecular functions is considered and recently described novel roles for JMJD6 in cancer and immune biology are reviewed. The increased knowledge of JMJD6 functions has wider implications for our general understanding of the JmjC protein family of which JMJD6 is a member.
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Affiliation(s)
- Janice Kwok
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh Edinburgh, UK
| | - Marie O'Shea
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh Edinburgh, UK
| | - David A Hume
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh Edinburgh, UK
| | - Andreas Lengeling
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh Edinburgh, UK
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93
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Yao X, Gao H, Li C, Wu L, Bai J, Wang J, Li Y, Zhang Y. Analysis of Ki67, HMGA1, MDM2, and RB expression in nonfunctioning pituitary adenomas. J Neurooncol 2017; 132:199-206. [PMID: 28255749 PMCID: PMC5378727 DOI: 10.1007/s11060-016-2365-9] [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: 06/06/2016] [Accepted: 12/23/2016] [Indexed: 12/27/2022]
Abstract
Nonfunctioning pituitary adenomas (NFPAs) are the most prevalent type of pituitary macro-adenoma. Clarifying the relationship between NFPA markers and disease progression or recurrence could provide a basis for administration of adjuvant treatments. The present study examined the expression levels of high-mobility group (HMG)A1, Ki-67, mouse double minute 2 homolog (MDM2), and retinoblastoma (RB)with respect to NFPA recurrence. Immunohistochemistry was carried out using antibodies to Ki-67, MDM2, HMGA-1, and RB on tissue microarray slides of a cohort of 35 paired NFPA samples of primary and recurrence/regrowth tumors. Based on postoperative magnetic resonance imaging data, tumors were classified as recurrence (n = 20) included primary and recurrent tumors or regrowth (n = 15) included primary and regrowth tumors, which are paired. Protein expression was classified as negative or positive according to the H-score method and was analyzed with respect to clinical and pathological findings. MDM2-positive cases accounted for11/20 primary and 19/20 s recurrent tumors (χ2 = 8.533, P = 0.003), and 9/15 primary tumors and 15/15 s regrowth tumors (χ2 = 7.5, P = 0.006). MGA1-positive cases represented 9/20 primary tumors and 16/20 s recurrent tumors (χ2 = 5.227, P = 0.022), and 4/15 primary tumors and 12/15 s regrowth tumors (χ2 = 8.571, P = 0.003). There was no statistically significant difference in Ki-67 expression between primary and second recurrent/regrowth tumors although theKi67 labeling index was higher in the latter groups. RB was highly expressed in all groups with no significant difference between them. HMGA1 and MDM2 were more highly expressed in recurrence/regrowth cases of NFPA than in primary NFPA. HMGA1 and MDM2 are biomarkers and potential drug targets for NFPA treatment.
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Affiliation(s)
- Xiaohui Yao
- Key Laboratory of Central Nervous System Injury Research, Beijing Neurosurgical Institute, Capital Medical University, Tiantanxili 6#, Beijing, 100050, China.,Shanxi Provincial People's Hospital, Taiyuan, Shanxi, China
| | - Hua Gao
- Key Laboratory of Central Nervous System Injury Research, Beijing Neurosurgical Institute, Capital Medical University, Tiantanxili 6#, Beijing, 100050, China
| | - Chuzhong Li
- Key Laboratory of Central Nervous System Injury Research, Beijing Neurosurgical Institute, Capital Medical University, Tiantanxili 6#, Beijing, 100050, China
| | - Lijuan Wu
- Shanxi Provincial People's Hospital, Taiyuan, Shanxi, China
| | - Jiwei Bai
- Neurosurgical Department, Beijing Tiantan Hospital, Beijing, China
| | - Jichao Wang
- Department of Neurosurgery, Xinjiang Uygur Autonomous Region People's Hospital, Xinjiang, China
| | - Yangfang Li
- Key Laboratory of Central Nervous System Injury Research, Beijing Neurosurgical Institute, Capital Medical University, Tiantanxili 6#, Beijing, 100050, China
| | - Yazhuo Zhang
- Key Laboratory of Central Nervous System Injury Research, Beijing Neurosurgical Institute, Capital Medical University, Tiantanxili 6#, Beijing, 100050, China.
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94
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Li T, Liu H, Li X. Chemical Synthesis of HMGA1a Proteins with Post-translational Modifications via Ser/Thr Ligation. Org Lett 2016; 18:5944-5947. [DOI: 10.1021/acs.orglett.6b03056] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Tianlu Li
- Department of Chemistry,
State Key Lab of Synthetic Chemistry, The University of Hong Kong, Pokfulam, Hong Kong
| | - Heng Liu
- Department of Chemistry,
State Key Lab of Synthetic Chemistry, The University of Hong Kong, Pokfulam, Hong Kong
| | - Xuechen Li
- Department of Chemistry,
State Key Lab of Synthetic Chemistry, The University of Hong Kong, Pokfulam, Hong Kong
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95
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Zhen CY, Tatavosian R, Huynh TN, Duc HN, Das R, Kokotovic M, Grimm JB, Lavis LD, Lee J, Mejia FJ, Li Y, Yao T, Ren X. Live-cell single-molecule tracking reveals co-recognition of H3K27me3 and DNA targets polycomb Cbx7-PRC1 to chromatin. eLife 2016; 5. [PMID: 27723458 PMCID: PMC5056789 DOI: 10.7554/elife.17667] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 08/29/2016] [Indexed: 12/11/2022] Open
Abstract
The Polycomb PRC1 plays essential roles in development and disease pathogenesis. Targeting of PRC1 to chromatin is thought to be mediated by the Cbx family proteins (Cbx2/4/6/7/8) binding to histone H3 with a K27me3 modification (H3K27me3). Despite this prevailing view, the molecular mechanisms of targeting remain poorly understood. Here, by combining live-cell single-molecule tracking (SMT) and genetic engineering, we reveal that H3K27me3 contributes significantly to the targeting of Cbx7 and Cbx8 to chromatin, but less to Cbx2, Cbx4, and Cbx6. Genetic disruption of the complex formation of PRC1 facilitates the targeting of Cbx7 to chromatin. Biochemical analyses uncover that the CD and AT-hook-like (ATL) motif of Cbx7 constitute a functional DNA-binding unit. Live-cell SMT of Cbx7 mutants demonstrates that Cbx7 is targeted to chromatin by co-recognizing of H3K27me3 and DNA. Our data suggest a novel hierarchical cooperation mechanism by which histone modifications and DNA coordinate to target chromatin regulatory complexes. DOI:http://dx.doi.org/10.7554/eLife.17667.001
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Affiliation(s)
- Chao Yu Zhen
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Roubina Tatavosian
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Thao Ngoc Huynh
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Huy Nguyen Duc
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Raibatak Das
- Department of Integrative Biology, University of Colorado Denver, Denver, United States
| | - Marko Kokotovic
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Jonathan B Grimm
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Luke D Lavis
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, United States
| | - Jun Lee
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Frances J Mejia
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Yang Li
- Department of Chemistry, University of Colorado Denver, Denver, United States
| | - Tingting Yao
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, United States
| | - Xiaojun Ren
- Department of Chemistry, University of Colorado Denver, Denver, United States
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96
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A/T Run Geometry of B-form DNA Is Independent of Bound Methyl-CpG Binding Domain, Cytosine Methylation and Flanking Sequence. Sci Rep 2016; 6:31210. [PMID: 27502833 PMCID: PMC4977486 DOI: 10.1038/srep31210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 07/04/2016] [Indexed: 11/08/2022] Open
Abstract
DNA methylation in a CpG context can be recognised by methyl-CpG binding protein 2 (MeCP2) via its methyl-CpG binding domain (MBD). An A/T run next to a methyl-CpG maximises the binding of MeCP2 to the methylated DNA. The A/T run characteristics are reported here with an X-ray structure of MBD A140V in complex with methylated DNA. The A/T run geometry was found to be strongly stabilised by a string of conserved water molecules regardless of its flanking nucleotide sequences, DNA methylation and bound MBD. New water molecules were found to stabilise the Rett syndrome-related E137, whose carboxylate group is salt bridged to R133. A structural comparison showed no difference between the wild type and MBD A140V. However, differential scanning calorimetry showed that the melting temperature of A140V constructs in complex with methylated DNA was reduced by ~7 °C, although circular dichroism showed no changes in the secondary structure content for A140V. A band shift analysis demonstrated that the larger fragment of MeCP2 (A140V) containing the transcriptional repression domain (TRD) destabilises the DNA binding. These results suggest that the solution structure of MBD A140V may differ from the wild-type MBD although no changes in the biochemical properties of X-ray A140V were observed.
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97
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Lyst MJ, Connelly J, Merusi C, Bird A. Sequence-specific DNA binding by AT-hook motifs in MeCP2. FEBS Lett 2016; 590:2927-33. [PMID: 27461740 PMCID: PMC5028900 DOI: 10.1002/1873-3468.12328] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Revised: 07/20/2016] [Accepted: 07/21/2016] [Indexed: 11/11/2022]
Abstract
MeCP2 is a chromatin‐associated protein that is mutated in Rett syndrome. Its methyl‐CpG‐binding domain interacts with DNA containing methylated cytosine, but other modes of recruitment to the genome have also been proposed. Here, we use in vitro and in vivo assays to investigate the DNA binding specificity of two AT‐hook motifs in MeCP2. One exhibits robust sequence‐specific DNA binding, whereas the other is a much weaker AT‐hook. Our data indicate that these motifs are secondary contributors to DNA binding by MeCP2, and this view is supported by the absence of disease‐causing missense mutations at these sites.
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Affiliation(s)
- Matthew J Lyst
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - John Connelly
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Cara Merusi
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Adrian Bird
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
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98
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Zhou L, Liu Z, Liu Y, Kong D, Li T, Yu S, Mei H, Xu X, Liu H, Chen L, Luo L. A novel gene OsAHL1 improves both drought avoidance and drought tolerance in rice. Sci Rep 2016; 6:30264. [PMID: 27453463 PMCID: PMC4958981 DOI: 10.1038/srep30264] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 07/04/2016] [Indexed: 12/22/2022] Open
Abstract
A novel gene, OsAHL1, containing an AT-hook motif and a PPC domain was identified through genome-wide profiling and analysis of mRNAs by comparing the microarray of drought-challenged versus normally watered rice. The results indicated OsAHL1 has both drought avoidance and drought tolerance that could greatly improve drought resistance of the rice plant. Overexpression of OsAHL1 enhanced multiple stress tolerances in rice plants during both seedling and panicle development stages. Functional studies revealed that OsAHL1 regulates root development under drought condition to enhance drought avoidance, participates in oxidative stress response and also regulates the content of chlorophyll in rice leaves. OsAHL1 specifically binds to the A/T rich sequence region of promoters or introns, and hence directly regulates the expression of many stress related downstream genes.
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Affiliation(s)
- Liguo Zhou
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
- National Key Laboratory of Crop Genetic Improvement, College of Plant Science, Huazhong Agricultural University, Wuhan 430070, China
| | - Zaochang Liu
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Yunhua Liu
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Deyan Kong
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Tianfei Li
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Shunwu Yu
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Hanwei Mei
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Xiaoyan Xu
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Hongyan Liu
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Liang Chen
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
| | - Lijun Luo
- Shanghai Agrobiological Gene Center, Shanghai Academy of Agricultural Sciences, Shanghai 201106, China
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99
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Brain phosphorylation of MeCP2 at serine 164 is developmentally regulated and globally alters its chromatin association. Sci Rep 2016; 6:28295. [PMID: 27323888 PMCID: PMC4915018 DOI: 10.1038/srep28295] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/01/2016] [Indexed: 12/31/2022] Open
Abstract
MeCP2 is a transcriptional regulator whose functional alterations are responsible for several autism spectrum and mental disorders. Post-translational modifications (PTMs), and particularly differential phosphorylation, modulate MeCP2 function in response to diverse stimuli. Understanding the detailed role of MeCP2 phosphorylation is thus instrumental to ascertain how MeCP2 integrates the environmental signals and directs its adaptive transcriptional responses. The evolutionarily conserved serine 164 (S164) was found phosphorylated in rodent brain but its functional role has remained uncharacterized. We show here that phosphorylation of S164 in brain is dynamically regulated during neuronal maturation. S164 phosphorylation highly impairs MeCP2 binding to DNA in vitro and largely affects its nucleosome binding and chromatin affinity in vivo. Strikingly, the chromatin-binding properties of the global MeCP2 appear also extensively altered during the course of brain maturation. Functional assays reveal that proper temporal regulation of S164 phosphorylation controls the ability of MeCP2 to regulate neuronal morphology. Altogether, our results support the hypothesis of a complex PTM-mediated functional regulation of MeCP2 potentially involving a still poorly characterized epigenetic code. Furthermore, they demonstrate the relevance of the Intervening Domain of MeCP2 for binding to DNA.
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Filarsky M, Zillner K, Araya I, Villar-Garea A, Merkl R, Längst G, Németh A. The extended AT-hook is a novel RNA binding motif. RNA Biol 2016; 12:864-76. [PMID: 26156556 PMCID: PMC4615771 DOI: 10.1080/15476286.2015.1060394] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The AT-hook has been defined as a DNA binding peptide motif that contains a glycine-arginine-proline (G-R-P) tripeptide core flanked by basic amino acids. Recent reports documented variations in the sequence of AT-hooks and revealed RNA binding activity of some canonical AT-hooks, suggesting a higher structural and functional variability of this protein domain than previously anticipated. Here we describe the discovery and characterization of the extended AT-hook peptide motif (eAT-hook), in which basic amino acids appear symmetrical mainly at a distance of 12-15 amino acids from the G-R-P core. We identified 80 human and 60 mouse eAT-hook proteins and biochemically characterized the eAT-hooks of Tip5/BAZ2A, PTOV1 and GPBP1. Microscale thermophoresis and electrophoretic mobility shift assays reveal the nucleic acid binding features of this peptide motif, and show that eAT-hooks bind RNA with one order of magnitude higher affinity than DNA. In addition, cellular localization studies suggest a role for the N-terminal eAT-hook of PTOV1 in nucleocytoplasmic shuttling. In summary, our findings classify the eAT-hook as a novel nucleic acid binding motif, which potentially mediates various RNA-dependent cellular processes.
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Affiliation(s)
- Michael Filarsky
- a Biochemistry Center Regensburg ; University of Regensburg ; Regensburg , Germany
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