1
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Fujita KI, Yamazaki T, Mayeda A, Masuda S. Terminal regions of UAP56 and URH49 are required for their distinct complex formation functioning to an essential role in mRNA processing and export. Biochem Biophys Res Commun 2024; 703:149682. [PMID: 38377942 DOI: 10.1016/j.bbrc.2024.149682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Revised: 02/11/2024] [Accepted: 02/12/2024] [Indexed: 02/22/2024]
Abstract
UAP56 and URH49 are closely related RNA helicases that function in selective mRNA processing and export pathways to fine-tune gene expression through distinct complex formations. The complex formation of UAP56 and URH49 is believed to play a crucial role in regulating target mRNAs. However, the mechanisms underlying this complex formation have not been fully elucidated. Here we identified the regions essential for the complex formation of both helicases. The terminal regions of UAP56 and the C-terminal region of URH49 were indispensable for their respective complex formation. Further analysis revealed that a specific amino acid at the C-terminus of UAP56 is critical for its complex formation. Alanine substitution of this amino acid impairs its complex formation and subsequently affected its mRNA processing and export activity. Our study provides a deeper understanding of the basis for the complex formation between UAP56 and URH49.
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Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan; Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan; Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan; Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan; Department of Applied Biological Chemistry, Graduate School of Agriculture, Kindai University, Nara, Nara, Japan; Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan; Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
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2
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Fujita KI, Ito M, Irie M, Harada K, Fujiwara N, Ikeda Y, Yoshioka H, Yamazaki T, Kojima M, Mikami B, Mayeda A, Masuda S. Structural differences between the closely related RNA helicases, UAP56 and URH49, fashion distinct functional apo-complexes. Nat Commun 2024; 15:455. [PMID: 38225262 PMCID: PMC10789772 DOI: 10.1038/s41467-023-44217-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 12/05/2023] [Indexed: 01/17/2024] Open
Abstract
mRNA export is an essential pathway for the regulation of gene expression. In humans, closely related RNA helicases, UAP56 and URH49, shape selective mRNA export pathways through the formation of distinct complexes, known as apo-TREX and apo-AREX complexes, and their subsequent remodeling into similar ATP-bound complexes. Therefore, defining the unidentified components of the apo-AREX complex and elucidating the molecular mechanisms underlying the formation of distinct apo-complexes is key to understanding their functional divergence. In this study, we identify additional apo-AREX components physically and functionally associated with URH49. Furthermore, by comparing the structures of UAP56 and URH49 and performing an integrated analysis of their chimeric mutants, we exhibit unique structural features that would contribute to the formation of their respective complexes. This study provides insights into the specific structural and functional diversification of these two helicases that diverged from the common ancestral gene Sub2.
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Affiliation(s)
- Ken-Ichi Fujita
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan.
- Division of Cancer Stem Cell, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo, 104-0045, Japan.
| | - Misa Ito
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Midori Irie
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Kotaro Harada
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Naoko Fujiwara
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Yuya Ikeda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Hanae Yoshioka
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Tomohiro Yamazaki
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan
| | - Masaki Kojima
- School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, Hachioji, Tokyo, 192-0392, Japan
| | - Bunzo Mikami
- Research Institute for Sustainable Humanosphere, Kyoto University, Kyoto, 611-0011, Japan
- Institute of Advanced Energy, Kyoto University, Kyoto, 611-0011, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi, 470-1192, Japan
| | - Seiji Masuda
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Kyoto, 606-8502, Japan.
- Department of Food Science and Nutrition, Faculty of Agriculture Kindai University, Nara, Nara, 631-8505, Japan.
- Agricultural Technology and Innovation Research Institute, Kindai University, Nara, Nara, 631-8505, Japan.
- Antiaging Center, Kindai University, Higashiosaka, Osaka, 577-8502, Japan.
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Fukumura K, Sperotto L, Seuß S, Kang HS, Yoshimoto R, Sattler M, Mayeda A. SAP30BP interacts with RBM17/SPF45 to promote splicing in a subset of human short introns. Cell Rep 2023; 42:113534. [PMID: 38065098 DOI: 10.1016/j.celrep.2023.113534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 11/03/2023] [Accepted: 11/16/2023] [Indexed: 12/30/2023] Open
Abstract
Human pre-mRNA splicing requires the removal of introns with highly variable lengths, from tens to over a million nucleotides. Therefore, mechanisms of intron recognition and splicing are likely not universal. Recently, we reported that splicing in a subset of human short introns with truncated polypyrimidine tracts depends on RBM17 (SPF45), instead of the canonical splicing factor U2 auxiliary factor (U2AF) heterodimer. Here, we demonstrate that SAP30BP, a factor previously implicated in transcriptional control, is an essential splicing cofactor for RBM17. In vitro binding and nuclear magnetic resonance analyses demonstrate that a U2AF-homology motif (UHM) in RBM17 binds directly to a newly identified UHM-ligand motif in SAP30BP. We show that this RBM17-SAP30BP interaction is required to specifically recruit RBM17 to phosphorylated SF3B1 (SF3b155), a U2 small nuclear ribonucleoprotein (U2 snRNP) component in active spliceosomes. We propose a mechanism for splicing in a subset of short introns, in which SAP30BP guides RBM17 in the assembly of active spliceosomes.
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Affiliation(s)
- Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Luca Sperotto
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Bavarian NMR Center, TUM School of Natural Sciences, 85748 Garching, Germany
| | - Stefanie Seuß
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Bavarian NMR Center, TUM School of Natural Sciences, 85748 Garching, Germany
| | - Hyun-Seo Kang
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Bavarian NMR Center, TUM School of Natural Sciences, 85748 Garching, Germany
| | - Rei Yoshimoto
- Department of Applied Biological Sciences, Faculty of Agriculture, Setsunan University, Hirakata, Osaka 673-0101, Japan
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Bavarian NMR Center, TUM School of Natural Sciences, 85748 Garching, Germany
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
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Nagamine H, Yashiro M, Yoshimoto N, Izumi M, Sugimoto A, Nakahama K, Ogawa K, Matsumoto Y, Sawa K, Tani Y, Kaneda H, Mitsuoka S, Yamada K, Watanabe T, Aasai K, Fukumura K, Mayeda A, Kawaguchi T. RBM17 Expression Is Associated With the Efficacy of ICI Monotherapy in NSCLC With Low PD-L1 Expression. Anticancer Res 2023; 43:4663-4672. [PMID: 37772582 DOI: 10.21873/anticanres.16662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/04/2023] [Accepted: 09/05/2023] [Indexed: 09/30/2023]
Abstract
BACKGROUND/AIM Immune checkpoint inhibitors (ICIs) are currently a standard treatment tool for non-small cell lung cancer (NSCLC). RNA-binding motif protein 17 (RBM17), a splicing factor, is frequently over-expressed in NSCLC, but little is known about the role of RBM17 in the efficacy of ICIs for NSCLC. Thus, we investigated the correlation between RBM17 expression and ICI efficacy in NSCLC. PATIENTS AND METHODS Biopsy or surgical specimens were collected from patients with advanced or recurrent NSCLC who received ICI monotherapy or chemo-immunotherapy in a first-line setting. RBM17 expression was examined using immunohistochemistry. The correlation between the efficacy of ICI monotherapy or chemo-immunotherapy and RBM17 expression was evaluated. RESULTS Among the 218 cases, 115 (52.8%) cases were positive for RBM17 expression. RBM17 expression was not associated with the objective response rate (ORR) or progression-free survival (PFS) in either of the ICI monotherapy or chemo-immunotherapy groups. However, among those with a low PD-L1 expression level (PD-L1 <50%; n=86), RBM17 expression was significantly associated with a better ORR (p=0.045) and a better PFS (p<0.001) in the ICI monotherapy group, and was significantly associated with a poor ORR in the chemo-immunotherapy group (p=0.041). CONCLUSION RBM17 might be a useful predictive marker for a higher efficacy of ICI monotherapy in NSCLC patients with a low PD-L1 expression level.
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Affiliation(s)
- Hiroaki Nagamine
- Department of Respiratory Medicine, Osaka City University, Graduate School of Medicine, Osaka, Japan
| | - Masakazu Yashiro
- Molecular Oncology and Therapeutics, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan;
| | - Naoki Yoshimoto
- Department of Pulmonary Medicine, Ishikiriseiki Hospital, Higashiosaka, Japan
| | - Motohiro Izumi
- Department of Pulmonary Medicine, Bell land General Hospital, Sakai, Japan
| | - Akira Sugimoto
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Kenji Nakahama
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Koichi Ogawa
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Yoshiya Matsumoto
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Kenji Sawa
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Yoko Tani
- Department of Clinical Oncology, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Hiroyasu Kaneda
- Department of Clinical Oncology, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Shigeki Mitsuoka
- Department of Clinical Oncology, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Kazuhiro Yamada
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Tetsuya Watanabe
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Kazuhisa Aasai
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
| | - Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Center for Medical Science, Fujita Health University, Toyoake, Japan
| | - Tomoya Kawaguchi
- Department of Respiratory Medicine, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
- Department of Clinical Oncology, Osaka Metropolitan University, Graduate School of Medicine, Osaka, Japan
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5
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Chua HH, Kameyama T, Mayeda A, Yeh TH. Epstein-Barr Virus Enhances Cancer-Specific Aberrant Splicing of TSG101 Pre-mRNA. Int J Mol Sci 2022; 23:ijms23052516. [PMID: 35269659 PMCID: PMC8910672 DOI: 10.3390/ijms23052516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/21/2022] [Accepted: 02/21/2022] [Indexed: 11/16/2022] Open
Abstract
Tumor viruses gain control of cellular functions when they infect and transform host cells. Alternative splicing is one of the cellular processes exploited by tumor viruses to benefit viral replication and support oncogenesis. Epstein-Barr virus (EBV) participates in a number of cancers, as reported mostly in nasopharyngeal carcinoma (NPC) and Burkitt lymphoma (BL). Using RT-nested-PCR and Northern blot analysis in NPC and BL cells, here we demonstrate that EBV promotes specific alternative splicing of TSG101 pre-mRNA, which generates the TSG101∆154-1054 variant though the agency of its viral proteins, such as EBNA-1, Zta and Rta. The level of TSG101∆154-1054 is particularly enhanced upon EBV entry into the lytic cycle, increasing protein stability of TSG101 and causing the cumulative synthesis of EBV late lytic proteins, such as VCA and gp350/220. TSG101∆154-1054-mediated production of VCA and gp350/220 is blocked by the overexpression of a translational mutant of TSG101∆154-1054 or by the depletion of full-length TSG101, which is consistent with the known role of the TSG101∆154-1054 protein in stabilizing the TSG101 protein. NPC patients whose tumor tissues express TSG101∆154-1054 have high serum levels of anti-VCA antibodies and high levels of viral DNA in their tumors. Our findings highlight the functional importance of TSG101∆154-1054 in allowing full completion of the EBV lytic cycle to produce viral particles. We propose that targeting EBV-induced TSG101 alternative splicing has broad potential as a therapeutic to treat EBV-associated malignancies.
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Affiliation(s)
- Huey-Huey Chua
- Department of Pediatrics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 100226, Taiwan;
| | - Toshiki Kameyama
- Department of Physiology, School of Medicine, Fujita Health University, Toyoake 470-1192, Aichi, Japan;
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan
- Correspondence: (A.M.); (T.-H.Y.)
| | - Te-Huei Yeh
- Department of Otolaryngology, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 100225, Taiwan
- Correspondence: (A.M.); (T.-H.Y.)
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6
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Daisuke H, Kato H, Fukumura K, Mayeda A, Miyagi Y, Seiki M, Koshikawa N. Novel LAMC2 fusion protein has tumor-promoting properties in ovarian carcinoma. Cancer Sci 2021; 112:4957-4967. [PMID: 34689384 PMCID: PMC8645749 DOI: 10.1111/cas.15149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 08/10/2021] [Accepted: 09/15/2021] [Indexed: 12/19/2022] Open
Abstract
Laminins are heterotrimeric ECM proteins composed of α, β, and γ chains. The γ2 chain (Lm-γ2) is a frequently expressed monomer and its expression is closely associated with cancer progression. Laminin-γ2 contains an epidermal growth factor (EGF)-like domain in its domain III (DIII or LEb). Matrix metalloproteinases can cleave off the DIII region of Lm-γ2 that retains the ligand activity for EGF receptor (EGFR). Herein, we show that a novel short form of Lm-γ2 (Lm-γ2F) containing DIII is generated without requiring MMPs and chromosomal translocation between LAMC2 on chromosome 1 and NR6A1 gene locus on chromosome 9 in human ovarian cancer SKOV3 cells. Laminin-γ2F is expressed as a truncated form lacking domains I and II, which are essential for its association with Lm-α3 and -β3 chains of Lm-332. Secreted Lm-γ2F can act as an EGFR ligand activating the EGFR/AKT pathways more effectively than does the Lm-γ2 chain, which in turn promotes proliferation, survival, and motility of ovarian cancer cells. LAMC2-NR6A1 translocation was detected using in situ hybridization, and fusion transcripts were expressed in ovarian cancer cell tissues. Overexpression and suppression of fusion transcripts significantly increased and decreased the tumorigenic growth of cells in mouse models, respectively. To the best of our knowledge, this is the first report regarding a fusion gene of ECM showing that translocation of LAMC2 plays a crucial role in the malignant growth and progression of ovarian cancer cells and that the consequent product is a promising therapeutic target against ovarian cancers.
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MESH Headings
- Animals
- Cell Line, Tumor
- Cocarcinogenesis/genetics
- Cocarcinogenesis/metabolism
- Female
- Gene Expression Regulation, Neoplastic
- Humans
- Laminin/genetics
- Laminin/metabolism
- Mice, Inbred BALB C
- Mice, Nude
- Nuclear Receptor Subfamily 6, Group A, Member 1/genetics
- Nuclear Receptor Subfamily 6, Group A, Member 1/metabolism
- Oncogene Proteins, Fusion/genetics
- Oncogene Proteins, Fusion/metabolism
- Ovarian Neoplasms/genetics
- Ovarian Neoplasms/metabolism
- Ovarian Neoplasms/pathology
- Protein Subunits/genetics
- Protein Subunits/metabolism
- RNA Interference
- Xenograft Model Antitumor Assays/methods
- Mice
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Affiliation(s)
- Hoshino Daisuke
- Division of Cancer Cell ResearchKanagawa Cancer Center Research InstituteYokohamaJapan
| | - Hisamori Kato
- Division of GynecologyKanagawa Cancer Center HospitalYokohamaJapan
| | - Kazuhiro Fukumura
- Division of Gene Expression MechanismInstitute for Comprehensive Medical ScienceFujita Health UniversityToyoakeJapan
| | - Akila Mayeda
- Division of Gene Expression MechanismInstitute for Comprehensive Medical ScienceFujita Health UniversityToyoakeJapan
| | - Yohei Miyagi
- Division of Molecular Pathology and GeneticsKanagawa Cancer Center Research InstituteYokohamaJapan
| | - Motoharu Seiki
- Division of Cancer Cell ResearchInstitute of Medical ScienceUniversity of TokyoTokyoJapan
| | - Naohiko Koshikawa
- Division of Cancer Cell ResearchKanagawa Cancer Center Research InstituteYokohamaJapan
- Division of Cancer Cell ResearchInstitute of Medical ScienceUniversity of TokyoTokyoJapan
- Department of Life Science and TechnologyTokyo Institute of TechnologyYokohamaJapan
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Fukumura K, Venables JP, Mayeda A. SPF45/RBM17-dependent splicing and multidrug resistance to cancer chemotherapy. Mol Cell Oncol 2021; 8:1996318. [PMID: 35419480 PMCID: PMC8997263 DOI: 10.1080/23723556.2021.1996318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/10/2021] [Accepted: 10/13/2021] [Indexed: 06/14/2023]
Abstract
The early splicing complex A occupies at least eighty nucleotides of intron, in which U2AF covers the polypyrimidine tract. SPF45 (RBM17) functionally substitutes for U2AF on a subset of short introns. Since SPF45 expression confers resistance to various anticancer drugs, SPF45-dependent splicing may play a critical role in multidrug resistance.
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Affiliation(s)
- Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Julian P. Venables
- Science Sense, 2 Rue St Vincent, Salèlles du Bosc, 34700 Le Bosc, France
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
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8
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Fukumura K, Yoshimoto R, Sperotto L, Kang HS, Hirose T, Inoue K, Sattler M, Mayeda A. SPF45/RBM17-dependent, but not U2AF-dependent, splicing in a distinct subset of human short introns. Nat Commun 2021; 12:4910. [PMID: 34389706 PMCID: PMC8363638 DOI: 10.1038/s41467-021-24879-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 07/06/2021] [Indexed: 11/11/2022] Open
Abstract
Human pre-mRNA introns vary in size from under fifty to over a million nucleotides. We searched for essential factors involved in the splicing of human short introns by screening siRNAs against 154 human nuclear proteins. The splicing activity was assayed with a model HNRNPH1 pre-mRNA containing short 56-nucleotide intron. We identify a known alternative splicing regulator SPF45 (RBM17) as a constitutive splicing factor that is required to splice out this 56-nt intron. Whole-transcriptome sequencing of SPF45-deficient cells reveals that SPF45 is essential in the efficient splicing of many short introns. To initiate the spliceosome assembly on a short intron with the truncated poly-pyrimidine tract, the U2AF-homology motif (UHM) of SPF45 competes out that of U2AF65 (U2AF2) for binding to the UHM-ligand motif (ULM) of the U2 snRNP protein SF3b155 (SF3B1). We propose that splicing in a distinct subset of human short introns depends on SPF45 but not U2AF heterodimer. The length distribution of human pre-mRNA introns is very extensive. The authors demonstrate that splicing in a subset of short introns is dependent on SPF45 (RBM17), which replaces authentic U2AF-heterodimer on the truncated poly-pyrimidine tracts and interacts with the U2 snRNP protein SF3b155.
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Affiliation(s)
- Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.
| | - Rei Yoshimoto
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.,Department of Applied Biological Sciences, Faculty of Agriculture, Setsunan University, Hirakata, Osaka, Japan
| | - Luca Sperotto
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Bavarian NMR Center (BNMRZ), Chemistry Department, Technical University of Munich, Garching, Germany
| | - Hyun-Seo Kang
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Bavarian NMR Center (BNMRZ), Chemistry Department, Technical University of Munich, Garching, Germany
| | - Tetsuro Hirose
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Kunio Inoue
- Department of Biology, Graduate School of Science, Kobe University, Kobe, Hyogo, Japan
| | - Michael Sattler
- Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany.,Bavarian NMR Center (BNMRZ), Chemistry Department, Technical University of Munich, Garching, Germany
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan.
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9
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Otani Y, Fujita KI, Kameyama T, Mayeda A. The Exon Junction Complex Core Represses Cancer-Specific Mature mRNA Re-splicing: A Potential Key Role in Terminating Splicing. Int J Mol Sci 2021; 22:ijms22126519. [PMID: 34204574 PMCID: PMC8234774 DOI: 10.3390/ijms22126519] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/08/2021] [Indexed: 02/08/2023] Open
Abstract
Using TSG101 pre-mRNA, we previously discovered cancer-specific re-splicing of mature mRNA that generates aberrant transcripts/proteins. The fact that mRNA is aberrantly re-spliced in various cancer cells implies there must be an important mechanism to prevent deleterious re-splicing on the spliced mRNA in normal cells. We thus postulated that mRNA re-splicing is controlled by specific repressors, and we searched for repressor candidates by siRNA-based screening for mRNA re-splicing activity. We found that knock-down of EIF4A3, which is a core component of the exon junction complex (EJC), significantly promoted mRNA re-splicing. Remarkably, we could recapitulate cancer-specific mRNA re-splicing in normal cells by knock-down of any of the core EJC proteins, EIF4A3, MAGOH, or RBM8A (Y14), implicating the EJC core as the repressor of mRNA re-splicing often observed in cancer cells. We propose that the EJC core is a critical mRNA quality control factor to prevent over-splicing of mature mRNA.
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Affiliation(s)
- Yuta Otani
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan; (Y.O.); (K.-i.F.)
- Laboratories of Discovery Research, Nippon Shinyaku Co., Ltd., Kyoto 601-8550, Kyoto, Japan
| | - Ken-ichi Fujita
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan; (Y.O.); (K.-i.F.)
| | - Toshiki Kameyama
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan; (Y.O.); (K.-i.F.)
- Department of Physiology, School of Medicine, Fujita Health University, Toyoake 470-1192, Aichi, Japan
- Correspondence: (T.K.); (A.M.)
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan; (Y.O.); (K.-i.F.)
- Correspondence: (T.K.); (A.M.)
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10
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Yoshimoto R, Chhipi-Shrestha JK, Schneider-Poetsch T, Furuno M, Burroughs AM, Noma S, Suzuki H, Hayashizaki Y, Mayeda A, Nakagawa S, Kaida D, Iwasaki S, Yoshida M. Spliceostatin A interaction with SF3B limits U1 snRNP availability and causes premature cleavage and polyadenylation. Cell Chem Biol 2021; 28:1356-1365.e4. [PMID: 33784500 DOI: 10.1016/j.chembiol.2021.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 01/07/2021] [Accepted: 03/09/2021] [Indexed: 12/01/2022]
Abstract
RNA splicing, a highly conserved process in eukaryotic gene expression, is seen as a promising target for anticancer agents. Splicing is associated with other RNA processing steps, such as transcription and nuclear export; however, our understanding of the interaction between splicing and other RNA regulatory mechanisms remains incomplete. Moreover, the impact of chemical splicing inhibition on long non-coding RNAs (lncRNAs) has been poorly understood. Here, we demonstrate that spliceostatin A (SSA), a chemical splicing modulator that binds to the SF3B subcomplex of the U2 small nuclear ribonucleoprotein particle (snRNP), limits U1 snRNP availability in splicing, resulting in premature cleavage and polyadenylation of MALAT1, a nuclear lncRNA, as well as protein-coding mRNAs. Therefore, truncated transcripts are exported into the cytoplasm and translated, resulting in aberrant protein products. Our work demonstrates that active recycling of the splicing machinery maintains homeostasis of RNA processing beyond intron excision.
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Affiliation(s)
- Rei Yoshimoto
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan; Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Jagat K Chhipi-Shrestha
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan; Department of Biotechnology, Graduate School of Agricultural Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Tilman Schneider-Poetsch
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
| | - Masaaki Furuno
- RIKEN Center for Integrative Medical Sciences, Tsurumi-ku, Yokohama 230-0045, Japan
| | - A Maxwell Burroughs
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Shohei Noma
- RIKEN Center for Integrative Medical Sciences, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Harukazu Suzuki
- RIKEN Center for Integrative Medical Sciences, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yoshihide Hayashizaki
- RIKEN Preventive Medicine and Diagnosis Innovation Program, Wako, Saitama 351-0198, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Shinichi Nakagawa
- RNA Biology Laboratory, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido 060-0812, Japan
| | - Daisuke Kaida
- Department of Gene Expression and Regulation, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani, Toyama 930-0194, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo 100-0004 Japan.
| | - Minoru Yoshida
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan; Department of Biotechnology, Graduate School of Agricultural Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
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11
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Muraoka S, Fukumura K, Hayashi M, Kataoka N, Mayeda A, Kaida D. Rbm38 Reduces the Transcription Elongation Defect of the SMEK2 Gene Caused by Splicing Deficiency. Int J Mol Sci 2020; 21:ijms21228799. [PMID: 33233740 PMCID: PMC7699959 DOI: 10.3390/ijms21228799] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/14/2020] [Accepted: 11/19/2020] [Indexed: 11/30/2022] Open
Abstract
Pre-mRNA splicing is an essential mechanism for ensuring integrity of the transcriptome in eukaryotes. Therefore, splicing deficiency might cause a decrease in functional proteins and the production of nonfunctional, aberrant proteins. To prevent the production of such aberrant proteins, eukaryotic cells have several mRNA quality control mechanisms. In addition to the known mechanisms, we previously found that transcription elongation is attenuated to prevent the accumulation of pre-mRNA under splicing-deficient conditions. However, the detailed molecular mechanism behind the defect in transcription elongation remains unknown. Here, we showed that the RNA binding protein Rbm38 reduced the transcription elongation defect of the SMEK2 gene caused by splicing deficiency. This reduction was shown to require the N- and C-terminal regions of Rbm38, along with an important role being played by the RNA-recognition motif of Rbm38. These findings advance our understanding of the molecular mechanism of the transcription elongation defect caused by splicing deficiency.
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Affiliation(s)
- Shintaro Muraoka
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan; (S.M.); (M.H.)
| | - Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan; (K.F.); (A.M.)
| | - Megumi Hayashi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan; (S.M.); (M.H.)
| | - Naoyuki Kataoka
- Department of Animal Resource Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan;
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan; (K.F.); (A.M.)
| | - Daisuke Kaida
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan; (S.M.); (M.H.)
- Correspondence:
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12
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Yoshimoto R, Rahimi K, Hansen TB, Kjems J, Mayeda A. Biosynthesis of Circular RNA ciRS-7/CDR1as Is Mediated by Mammalian-wide Interspersed Repeats. iScience 2020; 23:101345. [PMID: 32683316 PMCID: PMC7371899 DOI: 10.1016/j.isci.2020.101345] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 04/18/2020] [Accepted: 07/02/2020] [Indexed: 01/07/2023] Open
Abstract
Circular RNAs (circRNAs) are stable non-coding RNAs with a closed circular structure. One of the best studied circRNAs is ciRS-7 (CDR1as), which acts as a regulator of the microRNA miR-7; however, its biosynthetic pathway has remained an enigma. Here we delineate the biosynthetic pathway of ciRS-7. The back-splicing events that form circRNAs are often facilitated by flanking inverted repeats of the primate-specific Alu elements. The ciRS-7 gene lacks these elements, but, instead, we identified a set of flanking inverted elements belonging to the mammalian-wide interspersed repeat (MIR) family. Splicing reporter assays in HEK293 cells demonstrated that these inverted MIRs are required to generate ciRS-7 through back-splicing, and CRISPR/Cas9-mediated deletions confirmed the requirement of the endogenous MIR elements in SH-SY5Y cells. Using bioinformatic searches, we identified several other MIR-dependent circRNAs and confirmed them experimentally. We propose that MIR-mediated RNA circularization is used to generate a subset of mammalian circRNAs. The circular RNA, ciRS-7 (CDR1as), functions as a regulator of miR-7 ciRS-7 is generated by back-splicing, not via intra-lariat splicing Back-splicing of ciRS-7 is promoted by the flanking inverted MIR elements The biosynthesis of a subset of mammalian circRNAs could be mediated by MIRs
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Affiliation(s)
- Rei Yoshimoto
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Karim Rahimi
- Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark; Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | - Thomas B Hansen
- Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark
| | - Jørgen Kjems
- Department of Molecular Biology and Genetics, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark; Interdisciplinary Nanoscience Center, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
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Kataoka N, Mayeda A, Ohno K. Editorial: RNA Diseases in Humans-From Fundamental Research to Therapeutic Applications. Front Mol Biosci 2019; 6:53. [PMID: 31380391 PMCID: PMC6646588 DOI: 10.3389/fmolb.2019.00053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/26/2019] [Indexed: 11/13/2022] Open
Affiliation(s)
- Naoyuki Kataoka
- Laboratory of Cell Regulation, Departments of Applied Animal Sciences and Applied Biological Chemistry, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
| | - Kinji Ohno
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Ohe K, Miyajima S, Abe I, Tanaka T, Hamaguchi Y, Harada Y, Horita Y, Beppu Y, Ito F, Yamasaki T, Terai H, Mori M, Murata Y, Tanabe M, Ashida K, Kobayashi K, Enjoji M, Yanase T, Harada N, Utsumi T, Mayeda A. HMGA1a induces alternative splicing of estrogen receptor alpha in MCF-7 human breast cancer cells. J Steroid Biochem Mol Biol 2018; 182:21-26. [PMID: 29678492 DOI: 10.1016/j.jsbmb.2018.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 12/23/2017] [Accepted: 04/13/2018] [Indexed: 12/11/2022]
Abstract
The high-mobility group A protein 1a (HMGA1a) protein is known as an oncogene whose expression level in cancer tissue correlates with the malignant potential, and known as a component of senescence-related structures connecting it to tumor suppressor networks in fibroblasts. HMGA1 protein binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. Our previous studies have shown that sequence-specific RNA-binding of HMGA1a induces exon-skipping of Presenilin-2 exon 5 in sporadic Alzheimer disease. Here we show that HMGA1a induced exon-skipping of the estrogen receptor alpha (ERα) gene and increased ERα46 mRNA expression in MCF-7 breast cancer cells. An RNA-decoy of HMGA1a efficiently blocked this event and reduced ERα46 protein expression. Blockage of HMGA1a RNA-binding property consequently induced cell growth through reduced ERα46 expression in MCF-7 cells and increased sensitivity to tamoxifen in the tamoxifen-resistant cell line, MCF-7/TAMR1. Stable expression of an HMGA1a RNA-decoy in MCF-7 cells exhibited decreased ERα46 protein expression and increased estrogen-dependent tumor growth when these cells were implanted in nude mice. These results show HMGA1a is involved in alternative splicing of the ERα gene and related to estrogen-related growth as well as tamoxifen sensitivity in MCF-7 breast cancer cells.
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Affiliation(s)
- Kenji Ohe
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan.
| | - Shinsuke Miyajima
- Department of Breast Surgery, School of Medicine, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Ichiro Abe
- Department of Endocrinology and Diabetes Mellitus, Fukuoka University Chikushi Hospital, Chikushino city, 818-8502, Japan
| | - Tomoko Tanaka
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Yuriko Hamaguchi
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Yoshihiro Harada
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Yuta Horita
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Yuki Beppu
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Fumiaki Ito
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Takafumi Yamasaki
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Hiroki Terai
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Masayoshi Mori
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Yusuke Murata
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Makito Tanabe
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Kenji Ashida
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kunihisa Kobayashi
- Department of Endocrinology and Diabetes Mellitus, Fukuoka University Chikushi Hospital, Chikushino city, 818-8502, Japan
| | - Munechika Enjoji
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Toshihiko Yanase
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka, 814-180, Japan
| | - Nobuhiro Harada
- Department of Biochemistry, School of Medicine, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Toshiaki Utsumi
- Department of Breast Surgery, School of Medicine, Fujita Health University, Toyoake, Aichi 470-1192, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science (ICMS), Fujita Health University, Aichi, Toyoake, 470-1192, Japan
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15
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Ohe K, Miyajima S, Tanaka T, Hamaguchi Y, Harada Y, Horita Y, Beppu Y, Ito F, Yamasaki T, Terai H, Mori M, Murata Y, Tanabe M, Abe I, Ashida K, Kobayashi K, Enjoji M, Nomiyama T, Yanase T, Harada N, Utsumi T, Mayeda A. HMGA1a Induces Alternative Splicing of the Estrogen Receptor-α lpha Gene by Trapping U1 snRNP to an Upstream Pseudo-5' Splice Site. Front Mol Biosci 2018; 5:52. [PMID: 29938207 PMCID: PMC6002489 DOI: 10.3389/fmolb.2018.00052] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022] Open
Abstract
Objectives: The high-mobility group A protein 1a (HMGA1a) protein is known as a transcription factor that binds to DNA, but recent studies have shown it exerts novel functions through RNA-binding. We were prompted to decipher the mechanism of HMGA1a-induced alternative splicing of the estrogen receptor alpha (ERα) that we recently reported would alter tamoxifen sensitivity in MCF-7 TAMR1 cells. Methods: Endogenous expression of full length ERα66 and its isoform ERα46 were evaluated in MCF-7 breast cancer cells by transient expression of HMGA1a and an RNA decoy (2′-O-methylated RNA of the HMGA1a RNA-binding site) that binds to HMGA1a. RNA-binding of HMGA1a was checked by RNA-EMSA. In vitro splicing assay was performed to check the direct involvement of HMGA1a in splicing regulation. RNA-EMSA assay in the presence of purified U1 snRNP was performed with psoralen UV crosslinking to check complex formation of HMGA1a-U1 snRNP at the upstream pseudo-5′ splice site of exon 1. Results: HMGA1a induced exon skipping of a shortened exon 1 of ERα in in vitro splicing assays that was blocked by the HMGA1a RNA decoy and sequence-specific RNA-binding was confirmed by RNA-EMSA. RNA-EMSA combined with psoralen UV crosslinking showed that HMGA1a trapped purified U1 snRNP at the upstream pseudo-5′ splice site. Conclusions: Regulation of ERα alternative splicing by an HMGA1a-trapped U1 snRNP complex at the upstream 5′ splice site of exon 1 offers novel insight on 5′ splice site regulation by U1 snRNP as well as a promising target in breast cancer therapy where alternative splicing of ERα is involved.
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Affiliation(s)
- Kenji Ohe
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Shinsuke Miyajima
- Department of Breast Surgery, Fujita Health University, Toyoake, Japan
| | - Tomoko Tanaka
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Yuriko Hamaguchi
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Yoshihiro Harada
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Yuta Horita
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Yuki Beppu
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Fumiaki Ito
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Takafumi Yamasaki
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Hiroki Terai
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Masayoshi Mori
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Yusuke Murata
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Makito Tanabe
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Ichiro Abe
- Department of Endocrinology and Diabetes Mellitus, Fukuoka University Chikushi Hospital, Chikushino, Japan
| | - Kenji Ashida
- Department of Medicine and Bioregulatory Science, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Kunihisa Kobayashi
- Department of Endocrinology and Diabetes Mellitus, Fukuoka University Chikushi Hospital, Chikushino, Japan
| | - Munechika Enjoji
- Department of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Fukuoka University, Fukuoka, Japan
| | - Takashi Nomiyama
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Toshihiko Yanase
- Department of Endocrinology and Diabetes Mellitus, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Nobuhiro Harada
- Department of Biochemistry, Fujita Health University, Toyoake, Japan
| | - Toshiaki Utsumi
- Department of Breast Surgery, Fujita Health University, Toyoake, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Japan
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16
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Fukumura K, Inoue K, Mayeda A. Splicing activator RNPS1 suppresses errors in pre-mRNA splicing: A key factor for mRNA quality control. Biochem Biophys Res Commun 2018; 496:921-926. [PMID: 29366779 DOI: 10.1016/j.bbrc.2018.01.120] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 01/18/2018] [Indexed: 02/06/2023]
Abstract
Human RNPS1 protein was first identified as a pre-mRNA splicing activator in vitro and RNPS1 regulates alternative splicing in cellulo. RNPS1 was also known as a peripheral factor of the exon junction complex (EJC). Here we show that cellular knockdown of RNPS1 induced a reduction of the wild-type aurora kinase B (AURKB) protein due to the induced aberrant pre-mRNA splicing events, indicating that the fidelity of AURKB pre-mRNA splicing was reduced. The major aberrant AURKB mRNA was derived from the upstream pseudo 5' and 3' splice sites in intron 5, which resulted in the production of the non-functional truncated AURKB protein. AURKB, is an essential mitotic factor, whose absence is known to cause multiple nuclei, and this multinucleation phenotype was recapitulated in RNPS1-knockdown cells. Importantly this RNPS1-knockdown phenotype was rescued by ectopic expression of AURKB, implying it is a major functional target of RNPS1. We found RNPS1 protein, not as a component of the EJC, binds directly to a specific element in the AURKB exon upstream of the authentic 5' splice site, and this binding is required for normal splicing. RNPS1-knockdown induces a parallel aberrant splicing pattern in a fully distinct pre-mRNA, MDM2, suggesting that RNPS1 is a global guardian of splicing fidelity. We conclude that RNPS1 is a key factor for the quality control of mRNAs that is essential for the phenotypes including cell division.
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Affiliation(s)
- Kazuhiro Fukumura
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan
| | - Kunio Inoue
- Department of Biology, Graduate School of Science, Kobe University, Kobe 657-8501, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake 470-1192, Aichi, Japan.
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17
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Yoshimoto R, Kaida D, Furuno M, Burroughs AM, Noma S, Suzuki H, Kawamura Y, Hayashizaki Y, Mayeda A, Yoshida M. Global analysis of pre-mRNA subcellular localization following splicing inhibition by spliceostatin A. RNA 2017; 23:47-57. [PMID: 27754875 PMCID: PMC5159648 DOI: 10.1261/rna.058065.116] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2016] [Accepted: 10/03/2016] [Indexed: 05/27/2023]
Abstract
Spliceostatin A (SSA) is a methyl ketal derivative of FR901464, a potent antitumor compound isolated from a culture broth of Pseudomonas sp no. 2663. These compounds selectively bind to the essential spliceosome component SF3b, a subcomplex of the U2 snRNP, to inhibit pre-mRNA splicing. However, the mechanism of SSA's antitumor activity is unknown. It is noteworthy that SSA causes accumulation of a truncated form of the CDK inhibitor protein p27 translated from CDKN1B pre-mRNA, which is involved in SSA-induced cell-cycle arrest. However, it is still unclear whether pre-mRNAs are uniformly exported from the nucleus following SSA treatment. We performed RNA-seq analysis on nuclear and cytoplasmic fractions of SSA-treated cells. Our statistical analyses showed that intron retention is the major consequence of SSA treatment, and a small number of intron-containing pre-mRNAs leak into the cytoplasm. Using a series of reporter plasmids to investigate the roles of intronic sequences in the pre-mRNA leakage, we showed that the strength of the 5' splice site affects pre-mRNA leakage. Additionally, we found that the level of pre-mRNA leakage is related to transcript length. These results suggest that the strength of the 5' splice site and the length of the transcripts are determinants of the pre-mRNA leakage induced by SF3b inhibitors.
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Affiliation(s)
- Rei Yoshimoto
- Chemical Genetics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Daisuke Kaida
- Chemical Genetics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Frontier Research Core for Life Sciences, University of Toyama, Toyama-shi, Toyama 930-0194, Japan
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama-shi, Toyama 930-0194, Japan
| | - Masaaki Furuno
- RIKEN Center for Life Science Technologies, Division of Genomic Technologies, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - A Maxwell Burroughs
- RIKEN Center for Life Science Technologies, Division of Genomic Technologies, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland 20894, USA
| | - Shohei Noma
- RIKEN Center for Life Science Technologies, Division of Genomic Technologies, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Harukazu Suzuki
- RIKEN Center for Life Science Technologies, Division of Genomic Technologies, Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Yumi Kawamura
- Chemical Genetics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
| | - Yoshihide Hayashizaki
- RIKEN Preventive Medicine and Diagnosis Innovation Program (PMI), Tsurumi-ku, Yokohama, Kanagawa 230-0045, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Minoru Yoshida
- Chemical Genetics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan
- Japan Science and Technology Corporation, CREST Research Project, Kawaguchi, Saitama 332-0012, Japan
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18
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Suzuki H, Aoki Y, Kameyama T, Saito T, Masuda S, Tanihata J, Nagata T, Mayeda A, Takeda S, Tsukahara T. Endogenous Multiple Exon Skipping and Back-Splicing at the DMD Mutation Hotspot. Int J Mol Sci 2016; 17:ijms17101722. [PMID: 27754374 PMCID: PMC5085753 DOI: 10.3390/ijms17101722] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/26/2016] [Accepted: 09/30/2016] [Indexed: 12/15/2022] Open
Abstract
Duchenne muscular dystrophy (DMD) is a severe muscular disorder. It was reported that multiple exon skipping (MES), targeting exon 45–55 of the DMD gene, might improve patients’ symptoms because patients who have a genomic deletion of all these exons showed very mild symptoms. Thus, exon 45–55 skipping treatments for DMD have been proposed as a potential clinical cure. Herein, we detected the expression of endogenous exons 44–56 connected mRNA transcript of the DMD using total RNAs derived from human normal skeletal muscle by reverse transcription polymerase chain reaction (RT-PCR), and identified a total of eight types of MES products around the hotspot. Surprisingly, the 5′ splice sites of recently reported post-transcriptional introns (remaining introns after co-transcriptional splicing) act as splicing donor sites for MESs. We also tested exon combinations to generate DMD circular RNAs (circRNAs) and determined the preferential splice sites of back-splicing, which are involved not only in circRNA generation, but also in MESs. Our results fit the current circRNA-generation model, suggesting that upstream post-transcriptional introns trigger MES and generate circRNA because its existence is critical for the intra-intronic interaction or for extremely distal splicing.
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Affiliation(s)
- Hitoshi Suzuki
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan.
| | - Yoshitsugu Aoki
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
| | - Toshiki Kameyama
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Takashi Saito
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
| | - Satoru Masuda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
| | - Jun Tanihata
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
| | - Tetsuya Nagata
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
- Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Bunkyoku, Tokyo 113-0034, Japan.
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan.
| | - Shin'ichi Takeda
- Department of Molecular Therapy, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), Kodaira, Tokyo 187-8502, Japan.
| | - Toshifumi Tsukahara
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan.
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19
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Abe A, Mizuta S, Okamoto A, Yamamoto Y, Kameyama T, Mayeda A, Emi N. Transcriptional activation of platelet-derived growth factor receptor α and GS homeobox 2 resulting from E26 transformation-specific variant 6 translocation in a case of acute myeloid leukemia with t(4;12)(q12;p13). Int J Lab Hematol 2016; 38:e15-8. [PMID: 26728794 DOI: 10.1111/ijlh.12450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
MESH Headings
- Chromosomes, Human, Pair 12
- Chromosomes, Human, Pair 4
- Gene Expression Regulation, Leukemic
- Homeodomain Proteins/genetics
- Humans
- In Situ Hybridization, Fluorescence
- Leukemia, Myeloid, Acute/diagnosis
- Leukemia, Myeloid, Acute/genetics
- Male
- Proto-Oncogene Proteins c-ets/genetics
- Receptor, Platelet-Derived Growth Factor alpha/genetics
- Repressor Proteins/genetics
- Transcriptional Activation
- Translocation, Genetic
- ETS Translocation Variant 6 Protein
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Affiliation(s)
- A Abe
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan.
| | - S Mizuta
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - A Okamoto
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Y Yamamoto
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - T Kameyama
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - A Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - N Emi
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
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20
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Abe A, Yamamoto Y, Iba S, Kanie T, Okamoto A, Tokuda M, Inaguma Y, Yanada M, Morishima S, Mizuta S, Akatsuka Y, Okamoto M, Kameyama T, Mayeda A, Emi N. ETV6-LPXN fusion transcript generated by t(11;12)(q12.1;p13) in a patient with relapsing acute myeloid leukemia with NUP98-HOXA9. Genes Chromosomes Cancer 2016; 55:242-50. [PMID: 26542893 DOI: 10.1002/gcc.22327] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Revised: 10/14/2015] [Accepted: 10/15/2015] [Indexed: 11/09/2022] Open
Abstract
ETV6, which encodes an ETS family transcription factor, is frequently rearranged in human leukemias. We show here that a patient with acute myeloid leukemia with t(7;11)(p15;p15) gained, at the time of relapse, t(11;12)(q12.1;p13) with a split ETV6 FISH signal. Using 3'-RACE PCR analysis, we found that ETV6 was fused to LPXN at 11q12.1, which encodes leupaxin. ETV6-LPXN, an in-frame fusion between exon 4 of ETV6 and exon 2 of LPXN, did not transform the interleukin-3-dependent 32D myeloid cell line to cytokine independence; however, an enhanced proliferative response was observed when these cells were treated with G-CSF without inhibition of granulocytic differentiation. The 32D and human leukemia cell lines each transduced with ETV6-LPXN showed enhanced migration towards the chemokine CXCL12. We show here for the first time that LPXN is a fusion partner of ETV6 and present evidence indicating that ETV6-LPXN plays a crucial role in leukemia progression through enhancing the response to G-CSF and CXCL12.
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Affiliation(s)
- Akihiro Abe
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Yukiya Yamamoto
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Sachiko Iba
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Tadaharu Kanie
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Akinao Okamoto
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Masutaka Tokuda
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Yoko Inaguma
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Masamitsu Yanada
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Satoko Morishima
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Shuichi Mizuta
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Yoshiki Akatsuka
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Masataka Okamoto
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
| | - Toshiki Kameyama
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi, Japan
| | - Nobuhiko Emi
- Department of Hematology, Fujita Health University, Toyoake, Aichi, Japan
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21
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Abe A, Yamamoto Y, Iba S, Okamoto A, Tokuda M, Inaguma Y, Yanada M, Morishima S, Kanie T, Tsuzuki M, Akatsuka Y, Mizuta S, Okamoto M, Kameyama T, Mayeda A, Emi N. NUP214-RAC1 and RAC1-COL12A1 Fusion in Complex Variant Translocations Involving Chromosomes 6, 7 and 9 in an Acute Myeloid Leukemia Case with DEK-NUP214. Cytogenet Genome Res 2015; 146:279-84. [PMID: 26517539 DOI: 10.1159/000441464] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/15/2015] [Indexed: 11/19/2022] Open
Abstract
DEK-NUP214 gene fusion in acute myeloid leukemia (AML) is associated with poor prognosis. It is most often a sole translocation and more rarely observed as complex chromosomal forms. We describe an AML case with complex karyotype abnormalities involving chromosome bands 6p23, 6q13, 7p22, and 9q34. RNA sequencing analysis revealed that exon 17 of NUP214 (9q34) was fused to exon 2 of RAC1 (7p22). We also detected that the 5'-end of intron 1 of RAC1 was fused with the antisense strand of intron 5 of COL12A1 (6q13). RT-PCR analysis confirmed the expression of DEK-NUP214, NUP214-RAC1, RAC1-COL12A1, NUP214, and RAC1. These results suggest that the 5'- and 3'-ends of NUP214 from the breakpoint in the same locus were fused to RAC1 and DEK, respectively, and the 5'-end of RAC1 was fused to COL12A1. The reading frame of NUP214 was not matched with RAC1; however, high expression of the RAC1 protein was detected by Western blotting. This study identifies the variant complex fusion genesNUP214-RAC1 and RAC1- COL12A1 in a case of AML.
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Affiliation(s)
- Akihiro Abe
- Department of Hematology, Fujita Health University, Toyoake, Japan
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22
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Yoshimoto R, Mayeda A, Yoshida M, Nakagawa S. MALAT1 long non-coding RNA in cancer. Biochim Biophys Acta 2015; 1859:192-9. [PMID: 26434412 DOI: 10.1016/j.bbagrm.2015.09.012] [Citation(s) in RCA: 136] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Revised: 09/24/2015] [Accepted: 09/28/2015] [Indexed: 02/09/2023]
Abstract
A recent massive parallel sequencing analysis has shown the fact that more than 80% of the human genome is transcribed into RNA. Among many kinds of the non-protein coding RNAs, we focus on the metastasis associated lung adenocarcinoma transcript 1 (MALAT1) that is a long non-coding RNA upregulated in metastatic carcinoma cells. Two molecular functions of MALAT1 have been proposed, one is the control of alternative splicing and the other is the transcriptional regulation. In this review, we document the molecular characteristics and functions of MALAT1 and shed light on the implication in the molecular pathology of various cancers. This article is part of a Special Issue entitled: Clues to long noncoding RNA taxonomy1, edited by Dr. Tetsuro Hirose and Dr. Shinichi Nakagawa.
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Affiliation(s)
- Rei Yoshimoto
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan; Chemical Genetics Laboratory, RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan.
| | - Akila Mayeda
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Minoru Yoshida
- Chemical Genetics Laboratory, RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan
| | - Shinichi Nakagawa
- RNA Biology Laboratory, RIKEN, Hirosawa, Wako, Saitama 351-0198, Japan
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23
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24
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Rahman MA, Masuda A, Ohe K, Ito M, Hutchinson DO, Mayeda A, Engel AG, Ohno K. HnRNP L and hnRNP LL antagonistically modulate PTB-mediated splicing suppression of CHRNA1 pre-mRNA. Sci Rep 2013; 3:2931. [PMID: 24121633 PMCID: PMC3796306 DOI: 10.1038/srep02931] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2013] [Accepted: 09/25/2013] [Indexed: 12/20/2022] Open
Abstract
CHRNA1 gene, encoding the muscle nicotinic acetylcholine receptor alpha subunit, harbors an inframe exon P3A. Inclusion of exon P3A disables assembly of the acetylcholine receptor subunits. A single nucleotide mutation in exon P3A identified in congenital myasthenic syndrome causes exclusive inclusion of exon P3A. The mutation gains a de novo binding affinity for a splicing enhancing RNA-binding protein, hnRNP LL, and displaces binding of a splicing suppressing RNA-binding protein, hnRNP L. The hnRNP L binds to another splicing repressor PTB through the proline-rich region and promotes PTB binding to the polypyrimidine tract upstream of exon P3A, whereas hnRNP LL lacking the proline-rich region cannot bind to PTB. Interaction of hnRNP L with PTB inhibits association of U2AF(65) and U1 snRNP with the upstream and downstream of P3A, respectively, which causes a defect in exon P3A definition. HnRNP L and hnRNP LL thus antagonistically modulate PTB-mediated splicing suppression of exon P3A.
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Affiliation(s)
- Mohammad Alinoor Rahman
- Division of Neurogenetics, Center for Neurological Diseases and Cancer, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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25
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Suzuki H, Kameyama T, Ohe K, Tsukahara T, Mayeda A. Nested introns in an intron: evidence of multi-step splicing in a large intron of the human dystrophin pre-mRNA. FEBS Lett 2013; 587:555-61. [PMID: 23395799 DOI: 10.1016/j.febslet.2013.01.057] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Revised: 01/18/2013] [Accepted: 01/23/2013] [Indexed: 10/27/2022]
Abstract
The mechanisms by which huge human introns are spliced out precisely are poorly understood. We analyzed large intron 7 (110199 nucleotides) generated from the human dystrophin (DMD) pre-mRNA by RT-PCR. We identified branching between the authentic 5' splice site and the branch point; however, the sequences far from the branch site were not detectable. This RT-PCR product was resistant to exoribonuclease (RNase R) digestion, suggesting that the detected lariat intron has a closed loop structure but contains gaps in its sequence. Transient and concomitant generation of at least two branched fragments from nested introns within large intron 7 suggests internal nested splicing events before the ultimate splicing at the authentic 5' and 3' splice sites. Nested splicing events, which bring the authentic 5' and 3' splice sites into close proximity, could be one of the splicing mechanisms for the extremely large introns.
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Affiliation(s)
- Hitoshi Suzuki
- School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292, Japan.
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26
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Kameyama T, Suzuki H, Mayeda A. Re-splicing of mature mRNA in cancer cells promotes activation of distant weak alternative splice sites. Nucleic Acids Res 2012; 40:7896-906. [PMID: 22675076 PMCID: PMC3439910 DOI: 10.1093/nar/gks520] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Transcripts of the human tumor susceptibility gene 101 (TSG101) are aberrantly spliced in many cancers. A major aberrant splicing event on the TSG101 pre-mRNA involves joining of distant alternative 5′ and 3′ splice sites within exon 2 and exon 9, respectively, resulting in the extensive elimination of the mRNA. The estimated strengths of the alternative splice sites are much lower than those of authentic splice sites. We observed that the equivalent aberrant mRNA could be generated from an intron-less TSG101 gene expressed ectopically in breast cancer cells. Remarkably, we identified a pathway-specific endogenous lariat RNA consisting solely of exonic sequences, predicted to be generated by a re-splicing between exon 2 and exon 9 on the spliced mRNA. Our results provide evidence for a two-step splicing pathway in which the initial constitutive splicing removes all 14 authentic splice sites, thereby bringing the weak alternative splice sites into close proximity. We also demonstrate that aberrant multiple-exon skipping of the fragile histidine triad (FHIT) pre-mRNA in cancer cells occurs via re-splicing of spliced FHIT mRNA. The re-splicing of mature mRNA can potentially generate mutation-independent diversity in cancer transcriptomes. Conversely, a mechanism may exist in normal cells to prevent potentially deleterious mRNA re-splicing events.
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Affiliation(s)
- Toshiki Kameyama
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
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27
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Sasaki-Haraguchi N, Shimada MK, Taniguchi I, Ohno M, Mayeda A. Mechanistic insights into human pre-mRNA splicing of human ultra-short introns: potential unusual mechanism identifies G-rich introns. Biochem Biophys Res Commun 2012; 423:289-94. [PMID: 22640740 DOI: 10.1016/j.bbrc.2012.05.112] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
It is unknown how very short introns (<65 nt; termed 'ultra-short' introns) could be spliced in a massive spliceosome (>2.7 MDa) without steric hindrance. By screening an annotated human transcriptome database (H-InvDB), we identified three model ultra-short introns: the 56-nt intron in the HNRNPH1 (hnRNP H1) gene, the 49-nt intron in the NDOR1 (NADPH dependent diflavin oxidoreductase 1) gene, and the 43-nt intron in the ESRP2 (epithelial splicing regulatory protein 2) gene. We verified that these endogenous ultra-short introns are spliced, and also recapitulated this in cultured cells transfected with the corresponding mini-genes. The splicing of these ultra-short introns was repressed by a splicing inhibitor, spliceostatin A, suggesting that SF3b (a U2 snRNP component) is involved in their splicing processes. The 56-nt intron containing a pyrimidine-rich tract was spliced out in a lariat form, and this splicing was inhibited by the disruption of U1, U2, or U4 snRNA. In contrast, the 49- and 43-nt introns were purine-rich overall without any pyrimidine-rich tract, and these lariat RNAs were not detectable. Remarkably, shared G-rich intronic sequences in the 49- and 43-nt introns were required for their splicing, suggesting that these ultra-short introns may recruit a novel auxiliary splicing mechanism linked to G-rich intronic splicing enhancers.
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Affiliation(s)
- Noriko Sasaki-Haraguchi
- Division of Gene Expression Mechanism, Institute for Comprehensive Medical Science, Fujita Health University, Toyoake, Aichi 470-1192, Japan
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28
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Miyagawa R, Tano K, Mizuno R, Nakamura Y, Ijiri K, Rakwal R, Shibato J, Masuo Y, Mayeda A, Hirose T, Akimitsu N. Identification of cis- and trans-acting factors involved in the localization of MALAT-1 noncoding RNA to nuclear speckles. RNA 2012; 18:738-51. [PMID: 22355166 PMCID: PMC3312561 DOI: 10.1261/rna.028639.111] [Citation(s) in RCA: 172] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2011] [Accepted: 12/15/2011] [Indexed: 05/26/2023]
Abstract
MALAT-1 noncoding RNA is localized to nuclear speckles despite its mRNA-like characteristics. Here, we report the identification of several key factors that promote the localization of MALAT-1 to nuclear speckles and also provide evidence that MALAT-1 is involved in the regulation of gene expression. Heterokaryon assays revealed that MALAT-1 does not shuttle between the nucleus and cytoplasm. RNAi-mediated repression of the nuclear speckle proteins, RNPS1, SRm160, or IBP160, which are well-known mRNA processing factors, resulted in the diffusion of MALAT-1 to the nucleoplasm. We demonstrated that MALAT-1 contains two distinct elements directing transcripts to nuclear speckles, which were also capable of binding to RNPS1 in vitro. Depletion of MALAT-1 represses the expression of several genes. Taken together, our results suggest that RNPS1, SRm160, and IBP160 contribute to the localization of MALAT-1 to nuclear speckles, where MALAT-1 could be involved in regulating gene expression.
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Affiliation(s)
- Ryu Miyagawa
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Keiko Tano
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Rie Mizuno
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yo Nakamura
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Kenichi Ijiri
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Randeep Rakwal
- Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST) West, Tsukuba, Ibaraki 305-8569, Japan
| | - Junko Shibato
- Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST) West, Tsukuba, Ibaraki 305-8569, Japan
| | - Yoshinori Masuo
- Health Technology Research Center, National Institute of Advanced Industrial Science and Technology (AIST) West, Tsukuba, Ibaraki 305-8569, Japan
| | - Akila Mayeda
- Institute for Comprehensive Medical Science (ICMS), Fujita Health University, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan
| | - Tetsuro Hirose
- Functional RNomics Team, Biomedicinal Information Research Center, AIST, Tokyo 135-0064, Japan
| | - Nobuyoshi Akimitsu
- Radioisotope Center, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
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29
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Mayeda A, Manabe T, Ohe K. [Oncogenic HMGA1a protein causes sporadic Alzheimer's disease-associated aberrant splicing]. Tanpakushitsu Kakusan Koso 2009; 54:2245-2250. [PMID: 21089648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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30
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Kozell L, Belknap JK, Hofstetter JR, Mayeda A, Buck KJ. Mapping a locus for alcohol physical dependence and associated withdrawal to a 1.1 Mb interval of mouse chromosome 1 syntenic with human chromosome 1q23.2-23.3. Genes Brain Behav 2008; 7:560-7. [PMID: 18363856 DOI: 10.1111/j.1601-183x.2008.00391.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Physiological dependence and associated withdrawal episodes are thought to constitute a motivational force perpetuating continued alcohol use/abuse. Although no animal model duplicates alcoholism, models for specific factors, like the withdrawal syndrome, are useful to identify potential determinants of liability in humans. We previously detected quantitative trait loci (QTLs) with large effects on predisposition to physical dependence and associated withdrawal following chronic or acute alcohol exposure to a large region of chromosome 1 in mice (Alcdp1 and Alcw1, respectively). Here, we provide the first confirmation of Alcw1 in a congenic strain, and, using interval-specific congenic strains, narrow its position to a minimal 1.1 Mb (maximal 1.7 Mb) interval syntenic with human chromosome 1q23.2-23.3. We also report the development of a small donor segment congenic that confirms capture of a gene(s) affecting physical dependence after chronic alcohol exposure within this small interval. This congenic will be invaluable for determining whether this interval harbors a gene(s) involved in additional alcohol responses for which QTLs have been detected on distal chromosome 1, including alcohol consumption, alcohol-conditioned aversion and -induced ataxia. The possibility that this QTL plays an important role in such diverse responses to alcohol makes it an important target. Moreover, human studies have identified markers on chromosome 1q associated with alcoholism, although this association is still suggestive and mapped to a large region. Thus, the fine mapping of this QTL and analyses of the genes within the QTL interval can inform developing models for genetic determinants of alcohol dependence in humans.
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Affiliation(s)
- L Kozell
- Department of Veterans Affairs Medical Center, Portland, OR, USA
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31
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Manabe T, Ohe K, Katayama T, Matsuzaki S, Yanagita T, Okuda H, Bando Y, Imaizumi K, Reeves R, Tohyama M, Mayeda A. HMGA1a: sequence-specific RNA-binding factor causing sporadic Alzheimer's disease-linked exon skipping of presenilin-2 pre-mRNA. Genes Cells 2007; 12:1179-91. [PMID: 17903177 DOI: 10.1111/j.1365-2443.2007.01123.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Aberrant exon 5 skipping of presenilin-2 (PS2) pre-mRNA produces a deleterious protein isoform PS2V, which is almost exclusively observed in the brains of sporadic Alzheimer's disease patients. PS2V over-expression in vivo enhances susceptibility to various endoplasmic reticulum (ER) stresses and increases production of amyloid-beta peptides. We previously purified and identified high mobility group A protein 1a (HMGA1a) as a trans-acting factor responsible for aberrant exon 5 skipping. Using heterologous pre-mRNAs, here we demonstrate that a specific HMGA1a-binding sequence in exon 5 adjacent to the 5' splice site is necessary for HMGA1a to inactivate the 5' splice site. An aberrant HMGA1a-U1 snRNP complex was detected on the HMGA1a-binding site adjacent to the 5' splice site during the early splicing reaction. A competitor 2'-O-methyl RNA (2'-O-Me RNA) consisting of the HMGA1a-binding sequence markedly repressed exon 5 skipping of PS2 pre-mRNA in vitro and in vivo. Finally, HMGA1a-induced cell death under ER stress was prevented by transfection of the competitor 2'-O-Me RNA. These results provide insights into the molecular basis for PS2V-associated neurodegenerative diseases that are initiated by specific RNA binding of HMGA1a.
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Affiliation(s)
- Takayuki Manabe
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka 565-0871, Japan
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Suzuki H, Zuo Y, Wang J, Zhang MQ, Malhotra A, Mayeda A. Characterization of RNase R-digested cellular RNA source that consists of lariat and circular RNAs from pre-mRNA splicing. Nucleic Acids Res 2006; 34:e63. [PMID: 16682442 PMCID: PMC1458517 DOI: 10.1093/nar/gkl151] [Citation(s) in RCA: 474] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Besides linear RNAs, pre-mRNA splicing generates three forms of RNAs: lariat introns, Y-structure introns from trans-splicing, and circular exons through exon skipping. To study the persistence of excised introns in total cellular RNA, we used three Escherichia coli 3' to 5' exoribonucleases. Ribonuclease R (RNase R) thoroughly degrades the abundant linear RNAs and the Y-structure RNA, while preserving the loop portion of a lariat RNA. Ribonuclease II (RNase II) and polynucleotide phosphorylase (PNPase) also preserve the lariat loop, but are less efficient in degrading linear RNAs. RNase R digestion of the total RNA from human skeletal muscle generates an RNA pool consisting of lariat and circular RNAs. RT-PCR across the branch sites confirmed lariat RNAs and circular RNAs in the pool generated by constitutive and alternative splicing of the dystrophin pre-mRNA. Our results indicate that RNase R treatment can be used to construct an intronic cDNA library, in which majority of the intron lariats are represented. The highly specific activity of RNase R implies its ability to screen for rare intragenic trans-splicing in any target gene with a large background of cis-splicing. Further analysis of the intronic RNA pool from a specific tissue or cell will provide insights into the global profile of alternative splicing.
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Affiliation(s)
| | | | - Jinhua Wang
- Cold Spring Harbor Laboratory1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | - Michael Q. Zhang
- Cold Spring Harbor Laboratory1 Bungtown Road, Cold Spring Harbor, NY 11724, USA
| | | | - Akila Mayeda
- To whom correspondence should be addressed. Tel: +1 305 243 4621; Fax: +1 305 243 3065;
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33
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Tarapore P, Shinmura K, Suzuki H, Tokuyama Y, Kim SH, Mayeda A, Fukasawa K. Thr199phosphorylation targets nucleophosmin to nuclear speckles and represses pre-mRNA processing. FEBS Lett 2005; 580:399-409. [PMID: 16376875 DOI: 10.1016/j.febslet.2005.12.022] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2005] [Revised: 12/05/2005] [Accepted: 12/07/2005] [Indexed: 11/29/2022]
Abstract
Nucleophosmin (NPM) is a multifunctional phosphoprotein, being involved in ribosome assembly, pre-ribosomal RNA processing, DNA duplication, nucleocytoplasmic protein trafficking, and centrosome duplication. NPM is phosphorylated by several kinases, including nuclear kinase II, casein kinase 2, Polo-like kinase 1 and cyclin-dependent kinases (CDK1 and 2), and these phosphorylations modulate the activity and function of NPM. We have previously identified Thr(199) as the major phosphorylation site of NPM mediated by CDK2/cyclin E (and A), and this phosphorylation is involved in the regulation of centrosome duplication. In this study, we further examined the effect of CDK2-mediated phosphorylation of NPM by using the antibody that specifically recognizes NPM phosphorylated on Thr(199). We found that the phospho-Thr(199) NPM localized to dynamic sub-nuclear structures known as nuclear speckles, which are believed to be the sites of storage and/or assembly of pre-mRNA splicing factors. Phosphorylation on Thr(199) by CDK2/cyclin E (and A) targets NPM to nuclear speckles, and enhances the RNA-binding activity of NPM. Moreover, phospho-Thr(199) NPM, but not unphosphorylated NPM, effectively represses pre-mRNA splicing. These findings indicate the involvement of NPM in the regulation of pre-mRNA processing, and its activity is controlled by CDK2-mediated phosphorylation on Thr(199).
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Affiliation(s)
- Pheruza Tarapore
- Department of Cell Biology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0521, USA
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34
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Trembley JH, Tatsumi S, Sakashita E, Loyer P, Slaughter CA, Suzuki H, Endo H, Kidd VJ, Mayeda A. Activation of pre-mRNA splicing by human RNPS1 is regulated by CK2 phosphorylation. Mol Cell Biol 2005; 25:1446-57. [PMID: 15684395 PMCID: PMC547998 DOI: 10.1128/mcb.25.4.1446-1457.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human RNPS1 was originally characterized as a pre-mRNA splicing activator in vitro and was shown to regulate alternative splicing in vivo. RNPS1 was also identified as a protein component of the splicing-dependent mRNP complex, or exon-exon junction complex (EJC), and a role for RNPS1 in postsplicing processes has been proposed. Here we demonstrate that RNPS1 incorporates into active spliceosomes, enhances the formation of the ATP-dependent A complex, and promotes the generation of both intermediate and final spliced products. RNPS1 is phosphorylated in vivo and interacts with the CK2 (casein kinase II) protein kinase. Serine 53 (Ser-53) of RNPS1 was identified as the major phosphorylation site for CK2 in vitro, and the same site is also phosphorylated in vivo. The phosphorylation status of Ser-53 significantly affects splicing activation in vitro, but it does not perturb the nuclear localization of RNPS1. In vivo experiments indicated that the phosphorylation of RNPS1 at Ser-53 influences the efficiencies of both splicing and translation. We propose that RNPS1 is a splicing regulator whose activator function is controlled in part by CK2 phosphorylation.
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Affiliation(s)
- Janeen H Trembley
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, P.O. Box 016129, Miami, FL 33101-6129, USA
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35
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Jokan L, Dong AP, Mayeda A, Krainer AR, Xu RM. Crystallization and preliminary X-ray diffraction studies of UP1, the two-RRM domain of hnRNP A1. Acta Crystallogr D Biol Crystallogr 2005; 53:615-8. [PMID: 15299896 DOI: 10.1107/s0907444997003326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The N-terminal domain of hnRNP A1 protein, termed UP1, comprises two tandem RNA-recognition motifs, both of which are necessary for efficient RNA binding and for the alternative splicing activity of hnRNP A1. Recombinant human UPI expressed in E. coli has been crystallized in space group P2(1) with unit-cell dimensions a = 37.94, b = 43.98, c = 55.64 A and beta = 93.9 degrees. The unit-cell volume is consistent with one UP1 molecule per asymmetric unit and a calculated 49% solvent content. The crystal diffraction limit is higher than 1.3 A, and a data set to 2.0 A has been collected. Diffraction data from one platinum and two mercury derivatives have also been collected.
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Affiliation(s)
- L Jokan
- W. M. Keck Structural Biology Laboratory, Cold Spring Harbor, NY 11724, USA
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36
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Kondo S, Yamamoto N, Murakami T, Okumura M, Mayeda A, Imaizumi K. Tra2 beta, SF2/ASF and SRp30c modulate the function of an exonic splicing enhancer in exon 10 of tau pre-mRNA. Genes Cells 2004; 9:121-30. [PMID: 15009090 DOI: 10.1111/j.1356-9597.2004.00709.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Some of mutations in the tau gene, which were found in frontotemporal dementia with Parkinsonism linked to chromosome 17 (FTDP-17), affect alternative splicing of its exon 10 which encodes one of four microtubule-binding motifs. To examine the molecular mechanisms responsible for aberrant splicing of the tau gene containing mutations linked to FTDP-17, we performed Exon trapping and binding assay using tau exon 10 pre-mRNA and nuclear extracts of neuroblastoma cell lines and in vitro splicing using dsx-substrate. We determined that 5' site of tau exon 10 (nucleotides 12-45) possesses exonic splicing enhancer (ESE) activities in vitro splicing and the FTDP-17-linked mutations affect the ESE activities and alter the splicing patterns of tau exon 10. Tra2 beta directly and ASF/SF2 indirectly associated with the ESE of wild tau exon 10. The binding amounts of these SR proteins to tau exon 10 bearing N279K mutation increased and they enhanced splicing the mutant tau exon 10. SRp30c also enhanced the splicing of tau exon 10. These results suggest that mutations in tau exon 10 that are linked to FTDP-17 affect the ESE activities by altering the binding of some SR proteins to its pre-mRNA.
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Affiliation(s)
- Shinichi Kondo
- Division of Structural Cellular Biology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan
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37
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Sakashita E, Tatsumi S, Werner D, Endo H, Mayeda A. Human RNPS1 and its associated factors: a versatile alternative pre-mRNA splicing regulator in vivo. Mol Cell Biol 2004; 24:1174-87. [PMID: 14729963 PMCID: PMC321435 DOI: 10.1128/mcb.24.3.1174-1187.2004] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Human RNPS1 was originally purified and characterized as a pre-mRNA splicing activator, and its role in the postsplicing process has also been proposed recently. To search for factors that functionally interact with RNPS1, we performed a yeast two-hybrid screen with a human cDNA library. Four factors were identified: p54 (also called SRp54; a member of the SR protein family), human transformer 2 beta (hTra2 beta; an exonic splicing enhancer-binding protein), hLucA (a potential component of U1 snRNP), and pinin (also called DRS and MemA; a protein localized in nuclear speckles). The N-terminal region containing the serine-rich (S) domain, the central RNA recognition motif (RRM), and the C-terminal arginine/serine/proline-rich (RS/P) domain of RNPS1 interact with p54, pinin, and hTra2 beta, respectively. Protein-protein binding between RNPS1 and these factors was verified in vitro and in vivo. Overexpression of RNPS1 in HeLa cells induced exon skipping in a model beta-globin pre-mRNA and a human tra-2 beta pre-mRNA. Coexpression of RNPS1 with p54 cooperatively stimulated exon inclusion in an ATP synthase gamma-subunit pre-mRNA. The RS/P domain and RRM are necessary for the exon-skipping activity, whereas the S domain is important for the cooperative effect with p54. RNPS1 appears to be a versatile factor that regulates alternative splicing of a variety of pre-mRNAs.
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Affiliation(s)
- Eiji Sakashita
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida 33136-1019, USA
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38
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Domsic JK, Wang Y, Mayeda A, Krainer AR, Stoltzfus CM. Human immunodeficiency virus type 1 hnRNP A/B-dependent exonic splicing silencer ESSV antagonizes binding of U2AF65 to viral polypyrimidine tracts. Mol Cell Biol 2003; 23:8762-72. [PMID: 14612416 PMCID: PMC262674 DOI: 10.1128/mcb.23.23.8762-8772.2003] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) exonic splicing silencers (ESSs) inhibit production of certain spliced viral RNAs by repressing alternative splicing of the viral precursor RNA. Several HIV-1 ESSs interfere with spliceosome assembly by binding cellular hnRNP A/B proteins. Here, we have further characterized the mechanism of splicing repression using a representative HIV-1 hnRNP A/B-dependent ESS, ESSV, which regulates splicing at the vpr 3' splice site. We show that hnRNP A/B proteins bound to ESSV are necessary to inhibit E complex assembly by competing with the binding of U2AF65 to the polypyrimidine tracts of repressed 3' splice sites. We further show evidence suggesting that U1 snRNP binds the 5' splice site despite an almost complete block of splicing by ESSV. Possible splicing-independent functions of U1 snRNP-5' splice site interactions during virus replication are discussed.
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Affiliation(s)
- Jeffrey K Domsic
- Program in Molecular Biology, University of Iowa, Iowa City, Iowa 52242, USA
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39
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Manabe T, Katayama T, Sato N, Gomi F, Hitomi J, Yanagita T, Kudo T, Honda A, Mori Y, Matsuzaki S, Imaizumi K, Mayeda A, Tohyama M. Induced HMGA1a expression causes aberrant splicing of Presenilin-2 pre-mRNA in sporadic Alzheimer's disease. Cell Death Differ 2003; 10:698-708. [PMID: 12761578 DOI: 10.1038/sj.cdd.4401221] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The aberrant splicing isoform (PS2V), generated by exon 5 skipping of the Presenilin-2 (PS2) gene transcript, is a diagnostic feature of sporadic Alzheimer's disease (AD). We found PS2V is hypoxia-inducible in human neuroblastoma SK-N-SH cells. We purified a responsible trans-acting factor based on its binding to an exon 5 fragment. The factor was identified as the high mobility group A1a protein (HMGA1a; formerly HMG-I). HMGA1a bound to a specific sequence on exon 5, located upstream of the 5' splice site. HMGA1a expression was induced by hypoxia and the protein was accumulated in the nuclear speckles with the endogenous splicing factor SC35. Overexpression of HMGA1a generated PS2V, but PS2V was repressed by cotransfection with the U1 snRNP 70K protein that has a strong affinity to HMGA1a. HMGA1a could interfere with U1 snRNP binding to the 5' splice site and caused exon 5 skipping. HMGA1a levels were significantly increased in the brain tissue from sporadic AD patients. We propose a novel mechanism of sporadic AD that involves HMGA1a-induced aberrant splicing of PS2 pre-mRNA in the absence of any mutations.
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Affiliation(s)
- T Manabe
- Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Japan
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40
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Amada N, Tezuka T, Mayeda A, Araki K, Takei N, Todokoro K, Nawa H. A novel rat orthologue and homologue for the Drosophila crooked neck gene in neural stem cells and their immediate descendants. J Biochem 2003; 133:615-23. [PMID: 12801913 DOI: 10.1093/jb/mvg079] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The crooked neck (crn) gene of Drosophila melanogaster encodes a scaffold protein carrying multiple tetratricopeptide repeat (TPR) motifs, and its mutation results in a reduction in the number of neuroblasts and lethality during larval stages. Here, we isolated two structurally related genes from a rat embryonic brain cDNA library. One gene is the rat orthologue of crn, which encodes 690 amino acids including 16 copies of TPR. The other gene, ATH55, encodes an 855 amino acid protein including 21 TPR motifs, which presumably represents a rat crn homologue and an orthologue of human XAB2. Both genes are highly expressed in embryonic brain but their expressions decrease during development. ATH55-like immunoreactivity is present in the ventricular zone and newly formed cortical plate, while CRN-like immunoreactivity is more abundant in a younger ventricular zone. In agreement, both proteins were found to be enriched in cultured neural stem cells and to decrease in response to cell differentiation signals. As indicated for the yeast CRN-like protein, ATH55 and CRN immunoreactivities were both recovered in the nuclear fraction and detected in the splicing complex carrying pre-mRNA. These findings suggest that both TPR-motif-containing proteins are involved in RNA processing of mammalian neural stem cells and their immediate descendants.
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Affiliation(s)
- Naoki Amada
- Molecular Neurobiology, Brain Research Institute, Niigata University, Asahimachi-dori 1-757, Niigata 951-8585, Japan
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Abstract
The PITSLRE protein kinases, hereafter referred to as CDK11 because of their association with the cyclin L regulatory partner, belong to large molecular weight protein complexes that contain RNA polymerase II. These CDK11(p110) complexes have been reported to influence transcription as well as interact with the general pre-mRNA-splicing factor RNPS1. Some of these complexes may also play a role in pre-mRNA splicing. Using a two-hybrid interactive screen, the splicing protein 9G8 was identified as an in vivo partner for CDK11(p110). The identification of several splicing-related factors as CDK11(p110) interactors along with the close relationship between transcription and splicing indicated that CDK11(p110) might influence splicing activity directly. Immunodepletion of CDK11(p110) from splicing extracts greatly reduced the appearance of spliced products using an in vitro assay system. Moreover, the re-addition of these CDK11(p110) immune complexes to the CDK11(p110)-immunodepleted splicing reactions completely restored splicing activity. Similarly, the addition of purified CDK11(p110) amino-terminal domain protein was sufficient to inhibit the splicing reaction. Finally, 9G8 is a phosphoprotein in vivo and is a substrate for CDK11(p110) phosphorylation in vitro. These data are among the first demonstrations showing that a CDK activity is functionally coupled to the regulation of pre-mRNA-splicing events and further support the hypothesis that CDK11(p110) is in a signaling pathway that may help to coordinate transcription and RNA-processing events.
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Affiliation(s)
- Dongli Hu
- Department of Genetics and Tumor Cell Biology, St. Jude Children's Research Hospital, Memphis, Tennessee 38105, USA
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42
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Mayeda A, Suzuki H. [Pre-mRNA splicing: a source of a diversified gene expression network]. Tanpakushitsu Kakusan Koso 2003; 48:404-13. [PMID: 12696148] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- Akila Mayeda
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, USA.
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Liu X, Mayeda A, Tao M, Zheng ZM. Exonic splicing enhancer-dependent selection of the bovine papillomavirus type 1 nucleotide 3225 3' splice site can be rescued in a cell lacking splicing factor ASF/SF2 through activation of the phosphatidylinositol 3-kinase/Akt pathway. J Virol 2003; 77:2105-15. [PMID: 12525645 PMCID: PMC140879 DOI: 10.1128/jvi.77.3.2105-2115.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Bovine papillomavirus type 1 (BPV-1) late pre-mRNAs are spliced in keratinocytes in a differentiation-specific manner: the late leader 5' splice site alternatively splices to a proximal 3' splice site (at nucleotide 3225) to express L2 or to a distal 3' splice site (at nucleotide 3605) to express L1. Two exonic splicing enhancers, each containing two ASF/SF2 (alternative splicing factor/splicing factor 2) binding sites, are located between the two 3' splice sites and have been identified as regulating alternative 3' splice site usage. The present report demonstrates for the first time that ASF/SF2 is required under physiological conditions for the expression of BPV-1 late RNAs and for selection of the proximal 3' splice site for BPV-1 RNA splicing in DT40-ASF cells, a genetically engineered chicken B-cell line that expresses only human ASF/SF2 controlled by a tetracycline-repressible promoter. Depletion of ASF/SF2 from the cells by tetracycline greatly decreased viral RNA expression and RNA splicing at the proximal 3' splice site while increasing use of the distal 3' splice site in the remaining viral RNAs. Activation of cells lacking ASF/SF2 through anti-immunoglobulin M-B-cell receptor cross-linking rescued viral RNA expression and splicing at the proximal 3' splice site and enhanced Akt phosphorylation and expression of the phosphorylated serine/arginine-rich (SR) proteins SRp30s (especially SC35) and SRp40. Treatment with wortmannin, a specific phosphatidylinositol 3-kinase/Akt kinase inhibitor, completely blocked the activation-induced activities. ASF/SF2 thus plays an important role in viral RNA expression and splicing at the proximal 3' splice site, but activation-rescued viral RNA expression and splicing in ASF/SF2-depleted cells is mediated through the phosphatidylinositol 3-kinase/Akt pathway and is associated with the enhanced expression of other SR proteins.
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Affiliation(s)
- Xuefeng Liu
- HIV and AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
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44
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Hou VC, Lersch R, Gee SL, Ponthier JL, Lo AJ, Wu M, Turck CW, Koury M, Krainer AR, Mayeda A, Conboy JG. Decrease in hnRNP A/B expression during erythropoiesis mediates a pre-mRNA splicing switch. EMBO J 2002; 21:6195-204. [PMID: 12426391 PMCID: PMC137214 DOI: 10.1093/emboj/cdf625] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
A physiologically important alternative pre-mRNA splicing switch, involving activation of protein 4.1R exon 16 (E16) splicing, is required for the establishment of proper mechanical integrity of the erythrocyte membrane during erythropoiesis. Here we identify a conserved exonic splicing silencer element (CE(16)) in E16 that interacts with hnRNP A/B proteins and plays a role in repression of E16 splicing during early erythropoiesis. Experiments with model pre-mRNAs showed that CE(16) can repress splicing of upstream introns, and that mutagenesis or replacement of CE(16) can relieve this inhibition. An affinity selection assay with biotinylated CE(16) RNA demonstrated specific binding of hnRNP A/B proteins. Depletion of hnRNP A/B proteins from nuclear extract significantly increased E16 inclusion, while repletion with recombinant hnRNP A/B restored E16 silencing. Most importantly, differentiating mouse erythroblasts exhibited a stage-specific activation of the E16 splicing switch in concert with a dramatic and specific down-regulation of hnRNP A/B protein expression. These findings demonstrate that natural developmental changes in hnRNP A/B proteins can effect physiologically important switches in pre-mRNA splicing.
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Affiliation(s)
| | | | | | | | | | - Michael Wu
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
| | - Chris W. Turck
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
| | - Mark Koury
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
| | - Adrian R. Krainer
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
| | - Akila Mayeda
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
| | - John G. Conboy
- Lawrence Berkeley National Laboratory, Life Sciences Division and
Department of Molecular and Cellular Biology, University of California at Berkeley, Berkeley, CA 94720, University of California, San Francisco, HHMI, Department of Medicine and Cardiovascular Research Institute, San Francisco, CA 94143, Department of Medicine, Vanderbilt University, Veterans Affairs Medical Centers, Nashville, TN 37232, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724 and University of Miami School of Medicine, Department of Biochemistry and Molecular Biology, Miami, FL 33136, USA Corresponding author e-mail:
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45
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Cowper AE, Cáceres JF, Mayeda A, Screaton GR. Serine-arginine (SR) protein-like factors that antagonize authentic SR proteins and regulate alternative splicing. J Biol Chem 2001; 276:48908-14. [PMID: 11684676 DOI: 10.1074/jbc.m103967200] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have characterized two RNA-binding proteins, of apparent molecular masses of approximately 40 and 35 kDa, which possess a single N-terminal RNA-recognition motif (RRM) followed by a C-terminal domain rich in serine-arginine dipeptides. Their primary structures resemble the single-RRM serine-arginine (SR) protein, SC35; however their functional effects are quite distinctive. The 40-kDa protein cannot complement SR protein-deficient HeLa cell S100 extract and showed a dominant negative effect in vitro against the authentic SR proteins, SF2/ASF and SC35. Interestingly, the 40- and 35-kDa proteins antagonize SR proteins and activate the most distal alternative 5' splice site of adenovirus E1A pre-mRNA in vivo, an activity that is similar to that characterized previously for the heterogeneous nuclear ribonucleoprotein particles A/B group of proteins. A series of recombinant chimeric proteins consisting of domains from these proteins and SC35 in various combinations showed that the RRM, but not the C-terminal domain rich in serine-arginine dipeptides, has a dominant role in this activity. Because of the similarity to SR proteins we have named these proteins SRrp40 and SRrp35, respectively, for SR-repressor proteins of approximately 40 and approximately 35 kDa. Both factors show tissue- and cell type-specific patterns of expression. We propose that these two proteins are SR protein-like alternative splicing regulators that antagonize authentic SR proteins in the modulation of alternative 5' splice site choice.
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Affiliation(s)
- A E Cowper
- Human Immunology Unit, Weatherall Institute of Molecular Medicine, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
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46
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Zhu J, Mayeda A, Krainer AR. Exon identity established through differential antagonism between exonic splicing silencer-bound hnRNP A1 and enhancer-bound SR proteins. Mol Cell 2001; 8:1351-61. [PMID: 11779509 DOI: 10.1016/s1097-2765(01)00409-9] [Citation(s) in RCA: 282] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
SR proteins recognize exonic splicing enhancer (ESE) elements and promote exon use, whereas certain hnRNP proteins bind to exonic splicing silencer (ESS) elements and block exon recognition. We investigated how ESS3 in HIV-1 tat exon 3 blocks splicing promoted by one SR protein (SC35) but not another (SF2/ASF). hnRNP A1 mediates silencing by binding initially to a required high-affinity site in ESS3, which then promotes further hnRNP A1 association with the upstream region of the exon. Both SC35 and SF2/ASF recognize upstream ESE motifs, but only SF2/ASF prevents secondary hnRNP A1 binding, presumably by blocking its cooperative propagation along the exon. The differential antagonism between a negative and two positive regulators exemplifies how inclusion of an alternative exon can be modulated.
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Affiliation(s)
- J Zhu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
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47
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Bilodeau PS, Domsic JK, Mayeda A, Krainer AR, Stoltzfus CM. RNA splicing at human immunodeficiency virus type 1 3' splice site A2 is regulated by binding of hnRNP A/B proteins to an exonic splicing silencer element. J Virol 2001; 75:8487-97. [PMID: 11507194 PMCID: PMC115094 DOI: 10.1128/jvi.75.18.8487-8497.2001] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The synthesis of human immunodeficiency virus type 1 (HIV-1) mRNAs is a complex process by which more than 30 different mRNA species are produced by alternative splicing of a single primary RNA transcript. HIV-1 splice sites are used with significantly different efficiencies, resulting in different levels of mRNA species in infected cells. Splicing of Tat mRNA, which is present at relatively low levels in infected cells, is repressed by the presence of exonic splicing silencers (ESS) within the two tat coding exons (ESS2 and ESS3). These ESS elements contain the consensus sequence PyUAG. Here we show that the efficiency of splicing at 3' splice site A2, which is used to generate Vpr mRNA, is also regulated by the presence of an ESS (ESSV), which has sequence homology to ESS2 and ESS3. Mutagenesis of the three PyUAG motifs within ESSV increases splicing at splice site A2, resulting in increased Vpr mRNA levels and reduced skipping of the noncoding exon flanked by A2 and D3. The increase in Vpr mRNA levels and the reduced skipping also occur when splice site D3 is mutated toward the consensus sequence. By in vitro splicing assays, we show that ESSV represses splicing when placed downstream of a heterologous splice site. A1, A1(B), A2, and B1 hnRNPs preferentially bind to ESSV RNA compared to ESSV mutant RNA. Each of these proteins, when added back to HeLa cell nuclear extracts depleted of ESSV-binding factors, is able to restore splicing repression. The results suggest that coordinate repression of HIV-1 RNA splicing is mediated by members of the hnRNP A/B protein family.
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Affiliation(s)
- P S Bilodeau
- Department of Microbiology, University of Iowa, Iowa City, Iowa 52242, USA
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48
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Saunders LR, Perkins DJ, Balachandran S, Michaels R, Ford R, Mayeda A, Barber GN. Characterization of two evolutionarily conserved, alternatively spliced nuclear phosphoproteins, NFAR-1 and -2, that function in mRNA processing and interact with the double-stranded RNA-dependent protein kinase, PKR. J Biol Chem 2001; 276:32300-12. [PMID: 11438536 DOI: 10.1074/jbc.m104207200] [Citation(s) in RCA: 108] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report here the isolation and characterization of two proteins, NFAR-1 and -2, which were isolated through their ability to interact with the dsRNA-dependent protein kinase, PKR. The NFAR proteins, of 90 and 110 kDa, are derived from a single gene through alternative splicing and are evolutionarily conserved nuclear phosphoproteins that interact with double-stranded RNA. Both NFAR-1 and -2 are phosphorylated by PKR, reciprocally co-immunoprecipitate with PKR, and colocalize with the kinase in a diffuse nuclear pattern within the cell. Transfection studies indicate that the NFARs regulate gene expression at the level of transcription, probably during the processing of pre-mRNAs, an activity that was increased in fibroblasts lacking PKR. Subsequent functional analyses indicated that amino acids important for NFAR's activity were localized to the C terminus of the protein, a region that was found to specifically interact with FUS and SMN, proteins also known as regulators of RNA processing. Accordingly, both NFARs were found to associate with both pre-mRNAs and spliced mRNAs in post-transcriptional studies, similar to the known splicing factor ASF/SF-2. Collectively, our data indicate that the NFARs may facilitate double-stranded RNA-regulated gene expression at the level of post-transcription and possibly contribute to host defense-related mechanisms in the cell.
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Affiliation(s)
- L R Saunders
- Department of Microbiology and Immunology and Sylvester Comprehensive Cancer Center, University of Miami School of Medicine, Miami, Florida 33136, USA
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49
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Abstract
The formation of the active spliceosome, its recruitment to active areas of transcription, and its role in pre-mRNA splicing depends on the association of a number of multifunctional serine/arginine-rich (SR) proteins. ZNF265 is an arginine/serine-rich (RS) domain containing zinc finger protein with conserved pre-mRNA splicing protein motifs. Here we show that ZNF265 immunoprecipitates from splicing extracts in association with mRNA, and that it is able to alter splicing patterns of Tra2-beta1 transcripts in a dose-dependent manner in HEK 293 cells. Yeast two-hybrid analysis and immunoprecipitation indicated interaction of ZNF265 with the essential splicing factor proteins U1-70K and U2AF(35). Confocal microscopy demonstrated colocalization of ZNF265 with the motor neuron gene product SMN, the snRNP protein U1-70K, the SR protein SC35, and with the transcriptosomal components p300 and YY1. Transfection of HT-1080 cells with ZNF265-EGFP fusion constructs showed that nuclear localization of ZNF265 required the RS domain. Alignment with other RS domain-containing proteins revealed a high degree of SR dipeptide conservation. These data show that ZNF265 functions as a novel component of the mRNA processing machinery.
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MESH Headings
- Active Transport, Cell Nucleus
- Alternative Splicing
- Amino Acid Sequence
- Arginine/chemistry
- Blotting, Western
- Cell Line
- Cell Nucleus/metabolism
- Cloning, Molecular
- Conserved Sequence
- Dose-Response Relationship, Drug
- Fluorescent Antibody Technique, Indirect
- Humans
- Microscopy, Confocal
- Microscopy, Fluorescence
- Models, Genetic
- Molecular Sequence Data
- Plasmids/metabolism
- Precipitin Tests
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- RNA-Binding Proteins/chemistry
- RNA-Binding Proteins/physiology
- Sequence Homology, Amino Acid
- Serine/chemistry
- Spliceosomes/physiology
- Transfection
- Two-Hybrid System Techniques
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Affiliation(s)
- D J Adams
- The University of Sydney, Basic & Clinical Genomics Laboratory, Department of Physiology and Institute for Biomedical Research, Sydney, NSW 2006, Australia
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Inoue K, Hukuda S, Fardellon P, Yang ZQ, Nakai M, Katayama K, Ushiyama T, Saruhashi Y, Huang J, Mayeda A, Catteddu I, Obry C. Prevalence of large-joint osteoarthritis in Asian and Caucasian skeletal populations. Rheumatology (Oxford) 2001; 40:70-3. [PMID: 11157144 DOI: 10.1093/rheumatology/40.1.70] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE To determine ethnic variations of large-joint osteoarthritis (OA) in past populations. METHODS One thousand two hundred and nine adult skeletons, excavated from archaeological sites in Japan, China and France were assessed for OA as defined by the presence of eburnation. RESULTS Within Asian skeletal populations, elbow OA and patellofemoral joint OA were more common in hunter-gatherers than in agriculturalists. Compared with Caucasians, the Asian skeletal population had a higher prevalence of tibiofemoral joint OA. CONCLUSION The relative frequencies of OA within and between ethnic groups at certain joint sites have changed over time from the past to the present.
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Affiliation(s)
- K Inoue
- Department of Orthopaedic Surgery, Shiga University of Medical Science, Otsu, Japan
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