1
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Schwartz S, Wu C, Kajitani N. RNA elements that control human papillomavirus mRNA splicing-targets for therapy? J Med Virol 2024; 96:e29473. [PMID: 38362929 DOI: 10.1002/jmv.29473] [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: 12/22/2023] [Revised: 01/31/2024] [Accepted: 02/05/2024] [Indexed: 02/17/2024]
Abstract
Human papillomaviruses (HPVs) cause more than 4.5% of all cancer in the world and more than half of these cases are attributed to human papillomavirus type 16 (HPV16). Prophylactic vaccines are available but antiviral drugs are not. Novel targets for therapy are urgently needed. Alternative RNA splicing is extensively used by HPVs to express all their genes and HPV16 is no exception. This process must function to perfection since mis-splicing could perturb the HPV gene expression program by altering mRNA levels or by generating dysfunctional mRNAs. Cis-acting RNA elements on the viral mRNAs and their cognate cellular trans-acting factors control papillomavirus RNA splicing. The precise but delicate nature of the splicing process renders splicing sensitive to interference. As such, papillomavirus RNA splicing is a potential target for therapy. Here we summarize our current understanding of cis-acting HPV16 RNA elements that control HPV16 mRNA splicing via cellular proteins and discuss how they may be exploited as targets for therapy to papillomavirus infections and cancer.
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Affiliation(s)
- Stefan Schwartz
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Chengjun Wu
- School of Health and Life Sciences, University of Health and Rehabilitation Sciences, Qingdao, China
| | - Naoko Kajitani
- Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
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2
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Kirk A, Graham SV. The human papillomavirus late life cycle and links to keratinocyte differentiation. J Med Virol 2024; 96:e29461. [PMID: 38345171 DOI: 10.1002/jmv.29461] [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: 08/30/2023] [Revised: 12/21/2023] [Accepted: 01/25/2024] [Indexed: 02/15/2024]
Abstract
Regulation of human papillomavirus (HPV) gene expression is tightly linked to differentiation of the keratinocytes the virus infects. HPV late gene expression is confined to the cells in the upper layers of the epithelium where the virus capsid proteins are synthesized. As these proteins are highly immunogenic, and the upper epithelium is an immune-privileged site, this spatial restriction aids immune evasion. Many decades of work have contributed to the current understanding of how this restriction occurs at a molecular level. This review will examine what is known about late gene expression in HPV-infected lesions and will dissect the intricacies of late gene regulation. Future directions for novel antiviral approaches will be highlighted.
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Affiliation(s)
- Anna Kirk
- Centre for Virus Research, University of Glasgow, Glasgow, UK
| | - Sheila V Graham
- Centre for Virus Research, University of Glasgow, Glasgow, UK
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3
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Jönsson J, Wang L, Kajitani N, Schwartz S. A novel HPV16 splicing enhancer critical for viral oncogene expression and cell immortalization. Nucleic Acids Res 2024; 52:316-336. [PMID: 37994701 PMCID: PMC10783526 DOI: 10.1093/nar/gkad1099] [Citation(s) in RCA: 0] [Impact Index Per Article: 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] [Received: 03/24/2023] [Revised: 10/18/2023] [Accepted: 11/03/2023] [Indexed: 11/24/2023] Open
Abstract
High-risk carcinogenic human papillomaviruses (HPVs), e.g. HPV16, express the E6 and E7 oncogenes from two mRNAs that are generated in a mutually exclusive manner by splicing. The HPV16 E7 mRNA, also known as the E6*I/E7 mRNA, is produced by splicing between splice sites SD226 and SA409, while E6 mRNAs retain the intron between these splice sites. We show that splicing between HPV16 splice sites SD226 and SA409 is controlled by a splicing enhancer consisting of a perfect repeat of an adenosine-rich, 11 nucleotide sequence: AAAAGCAAAGA. Two nucleotide substitutions in both 11 nucleotide sequences specifically inhibited production of the spliced E6*I/E7 mRNA. As a result, production of E7 protein was reduced and the ability of HPV16 to immortalize human primary keratinocytes was abolished. The splicing-enhancing effect was mediated by the cellular TRAP150/THRAP3 protein that also enhanced splicing of other high-risk HPV E6*I/E7 mRNAs, but had no effect on low-risk HPV mRNAs. In summary, we have identified a novel splicing enhancer in the E6 coding region that is specific for high-risk HPVs and that is critically linked to HPV16 carcinogenic properties.
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Affiliation(s)
- Johanna Jönsson
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC-B9, 751 23 Uppsala, Sweden
| | - Lianqing Wang
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC-B9, 751 23 Uppsala, Sweden
- Center of Translational Medicine, Zibo Central Hospital, 255036 Zibo, China
| | - Naoko Kajitani
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC-B9, 751 23 Uppsala, Sweden
| | - Stefan Schwartz
- Department of Medical Biochemistry and Microbiology, Uppsala University, BMC-B9, 751 23 Uppsala, Sweden
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4
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Pollin G, De Assuncao T, Doria Jorge S, Chi YI, Charlesworth M, Madden B, Iovanna J, Zimmermann M, Urrutia R, Lomberk G. Writers and readers of H3K9me2 form distinct protein networks during the cell cycle that include candidates for H3K9 mimicry. Biosci Rep 2023; 43:BSR20231093. [PMID: 37782747 PMCID: PMC10611923 DOI: 10.1042/bsr20231093] [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: 06/13/2023] [Revised: 09/15/2023] [Accepted: 10/02/2023] [Indexed: 10/04/2023] Open
Abstract
Histone H3 lysine 9 methylation (H3K9me), which is written by the Euchromatic Histone Lysine Methyltransferases EHMT1 and EHMT2 and read by the heterochromatin protein 1 (HP1) chromobox (CBX) protein family, is dysregulated in many types of cancers. Approaches to inhibit regulators of this pathway are currently being evaluated for therapeutic purposes. Thus, knowledge of the complexes supporting the function of these writers and readers during the process of cell proliferation is critical for our understanding of their role in carcinogenesis. Here, we immunopurified each of these proteins and used mass spectrometry to define their associated non-histone proteins, individually and at two different phases of the cell cycle, namely G1/S and G2/M. Our findings identify novel binding proteins for these writers and readers, as well as corroborate known interactors, to show the formation of distinct protein complex networks in a cell cycle phase-specific manner. Furthermore, there is an organizational switch between cell cycle phases for interactions among specific writer-reader pairs. Through a multi-tiered bioinformatics-based approach, we reveal that many interacting proteins exhibit histone mimicry, based on an H3K9-like linear motif. Gene ontology analyses, pathway enrichment, and network reconstruction inferred that these comprehensive EHMT and CBX-associated interacting protein networks participate in various functions, including transcription, DNA repair, splicing, and membrane disassembly. Combined, our data reveals novel complexes that provide insight into key functions of cell cycle-associated epigenomic processes that are highly relevant for better understanding these chromatin-modifying proteins during cell cycle and carcinogenesis.
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Affiliation(s)
- Gareth Pollin
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Division of Research, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI Center, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | - Thiago M. De Assuncao
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Division of Research, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI Center, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | - Salomao Doria Jorge
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | - Young-In Chi
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Division of Research, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI Center, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | | | - Benjamin Madden
- Medical Genome Facility, Proteomics Core, Mayo Clinic, Rochester, MN, U.S.A
| | - Juan Iovanna
- Centre de Recherche en Cancérologie de Marseille (CRCM), INSERM U1068, CNRS UMR 7258, Aix-Marseille Université and Institut Paoli-Calmettes, Parc Scientifique et Technologique de Luminy, Marseille, France
| | - Michael T. Zimmermann
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Clinical and Translational Sciences Institute, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | - Raul Urrutia
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Division of Research, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI Center, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI, U.S.A
| | - Gwen Lomberk
- Linda T. and John A. Mellowes Center for Genomic Sciences and Precision Medicine, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Division of Research, Department of Surgery, Medical College of Wisconsin, Milwaukee, WI Center, Medical College of Wisconsin, Milwaukee, WI, U.S.A
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI, U.S.A
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5
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Sfaxi R, Biswas B, Boldina G, Cadix M, Servant N, Chen H, Larson DR, Dutertre M, Robert C, Vagner S. Post-transcriptional polyadenylation site cleavage maintains 3'-end processing upon DNA damage. EMBO J 2023; 42:e112358. [PMID: 36762421 PMCID: PMC10068322 DOI: 10.15252/embj.2022112358] [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: 08/12/2022] [Revised: 01/23/2023] [Accepted: 01/25/2023] [Indexed: 02/11/2023] Open
Abstract
The recognition of polyadenylation signals (PAS) in eukaryotic pre-mRNAs is usually coupled to transcription termination, occurring while pre-mRNA is chromatin-bound. However, for some pre-mRNAs, this 3'-end processing occurs post-transcriptionally, i.e., through a co-transcriptional cleavage (CoTC) event downstream of the PAS, leading to chromatin release and subsequent PAS cleavage in the nucleoplasm. While DNA-damaging agents trigger the shutdown of co-transcriptional chromatin-associated 3'-end processing, specific compensatory mechanisms exist to ensure efficient 3'-end processing for certain pre-mRNAs, including those that encode proteins involved in the DNA damage response, such as the tumor suppressor p53. We show that cleavage at the p53 polyadenylation site occurs in part post-transcriptionally following a co-transcriptional cleavage event. Cells with an engineered deletion of the p53 CoTC site exhibit impaired p53 3'-end processing, decreased mRNA and protein levels of p53 and its transcriptional target p21, and altered cell cycle progression upon UV-induced DNA damage. Using a transcriptome-wide analysis of PAS cleavage, we identify additional pre-mRNAs whose PAS cleavage is maintained in response to UV irradiation and occurring post-transcriptionally. These findings indicate that CoTC-type cleavage of pre-mRNAs, followed by PAS cleavage in the nucleoplasm, allows certain pre-mRNAs to escape 3'-end processing inhibition in response to UV-induced DNA damage.
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Affiliation(s)
- Rym Sfaxi
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Biswendu Biswas
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France.,INSERM U981, Gustave Roussy, Gustave Roussy, Villejuif, France.,Université Paris Sud, Université Paris-Saclay, Kremlin-Bicêtre, France
| | - Galina Boldina
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Mandy Cadix
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Nicolas Servant
- INSERM U900, Institut Curie, PSL Research University, Mines ParisTech, Paris, France
| | - Huimin Chen
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Daniel R Larson
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, NIH, Bethesda, MD, USA
| | - Martin Dutertre
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France
| | - Caroline Robert
- INSERM U981, Gustave Roussy, Gustave Roussy, Villejuif, France.,Université Paris Sud, Université Paris-Saclay, Kremlin-Bicêtre, France
| | - Stéphan Vagner
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, Orsay, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, INSERM U1278, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Paris, France
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6
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Bhattarai K, Holcik M. Diverse roles of heterogeneous nuclear ribonucleoproteins in viral life cycle. Front Virol 2022. [DOI: 10.3389/fviro.2022.1044652] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Understanding the host-virus interactions helps to decipher the viral replication strategies and pathogenesis. Viruses have limited genetic content and rely significantly on their host cell to establish a successful infection. Viruses depend on the host for a broad spectrum of cellular RNA-binding proteins (RBPs) throughout their life cycle. One of the major RBP families is the heterogeneous nuclear ribonucleoproteins (hnRNPs) family. hnRNPs are typically localized in the nucleus, where they are forming complexes with pre-mRNAs and contribute to many aspects of nucleic acid metabolism. hnRNPs contain RNA binding motifs and frequently function as RNA chaperones involved in pre-mRNA processing, RNA splicing, and export. Many hnRNPs shuttle between the nucleus and the cytoplasm and influence cytoplasmic processes such as mRNA stability, localization, and translation. The interactions between the hnRNPs and viral components are well-known. They are critical for processing viral nucleic acids and proteins and, therefore, impact the success of the viral infection. This review discusses the molecular mechanisms by which hnRNPs interact with and regulate each stage of the viral life cycle, such as replication, splicing, translation, and assembly of virus progeny. In addition, we expand on the role of hnRNPs in the antiviral response and as potential targets for antiviral drug research and development.
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7
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Kajitani N, Schwartz S. The role of RNA-binding proteins in the processing of mRNAs produced by carcinogenic papillomaviruses. Semin Cancer Biol 2022; 86:482-496. [PMID: 35181475 DOI: 10.1016/j.semcancer.2022.02.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [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: 12/07/2021] [Revised: 02/10/2022] [Accepted: 02/11/2022] [Indexed: 02/08/2023]
Abstract
Human papillomaviruses (HPV) are epitheliotropic DNA tumor viruses that are prevalent in the human population. A subset of the HPVs termed high-risk HPVs (HR-HPVs) are causative agents of anogenital cancers and head-and-neck cancers. Cancer is the result of persistent high-risk HPV infections that have not been cleared by the immune system of the host. These infections are characterized by dysregulated HPV gene expression, in particular constitutive high expression of the HPV E6 and E7 oncogenes and absence of the highly immunogenic viral L1 and L2 capsid proteins. HPVs make extensive use of alternative mRNA splicing to express its genes and are therefore highly dependent on cellular RNA-binding proteins for proper gene expression. Levels of RNA-binding proteins are altered in HPV-containing premalignant cervical lesions and in cervical cancer. Here we review our current knowledge of RNA-binding proteins that control HPV gene expression. We focus on RNA-binding proteins that control expression of the E6 and E7 oncogenes since they initiate and drive development of cancer and on the immunogenic L1 and L2 proteins as there silencing may contribute to immune evasion during carcinogenesis. Furthermore, cellular RNA-binding proteins are essential for HPV gene expression and as such may be targets for therapy to HPV infections and HPV-driven cancers.
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Affiliation(s)
- Naoko Kajitani
- Department of Medical Biochemistry and Microbiology (IMBIM), Uppsala University, BMC-B9, 751 23, Uppsala, Sweden; Department of Laboratory Medicine, Lund University, BMC-B13, 221 84, Lund, Sweden
| | - Stefan Schwartz
- Department of Medical Biochemistry and Microbiology (IMBIM), Uppsala University, BMC-B9, 751 23, Uppsala, Sweden; Department of Laboratory Medicine, Lund University, BMC-B13, 221 84, Lund, Sweden.
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8
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Spada S, Luke B, Danckwardt S. The Bidirectional Link Between RNA Cleavage and Polyadenylation and Genome Stability: Recent Insights From a Systematic Screen. Front Genet 2022; 13:854907. [PMID: 35571036 PMCID: PMC9095915 DOI: 10.3389/fgene.2022.854907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/28/2022] [Indexed: 11/13/2022] Open
Abstract
The integrity of the genome is governed by multiple processes to ensure optimal survival and to prevent the inheritance of deleterious traits. While significant progress has been made to characterize components involved in the DNA Damage Response (DDR), little is known about the interplay between RNA processing and the maintenance of genome stability. Here, we describe the emerging picture of an intricate bidirectional coupling between RNA processing and genome integrity in an integrative manner. By employing insights from a recent large-scale RNAi screening involving the depletion of more than 170 components that direct (alternative) polyadenylation, we provide evidence of bidirectional crosstalk between co-transcriptional RNA 3′end processing and the DDR in a manner that optimizes genomic integrity. We provide instructive examples illustrating the wiring between the two processes and show how perturbations at one end are either compensated by buffering mechanisms at the other end, or even propel the initial insult and thereby become disease-eliciting as evidenced by various disorders.
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Affiliation(s)
- Stefano Spada
- Posttranscriptional Gene Regulation, University Medical Centre Mainz, Mainz, Germany
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Centre Mainz, Mainz, Germany
- Centre for Thrombosis and Hemostasis (CTH), University Medical Centre Mainz, Mainz, Germany
| | - Brian Luke
- Institute of Molecular Biology (IMB), Mainz, Germany
- Institute of Developmental Biology and Neurobiology (IDN), Johannes Gutenberg University, Mainz, Germany
| | - Sven Danckwardt
- Posttranscriptional Gene Regulation, University Medical Centre Mainz, Mainz, Germany
- Institute for Clinical Chemistry and Laboratory Medicine, University Medical Centre Mainz, Mainz, Germany
- Centre for Thrombosis and Hemostasis (CTH), University Medical Centre Mainz, Mainz, Germany
- German Centre for Cardiovascular Research (DZHK), Berlin, Germany
- Centre for Healthy Aging (CHA) Mainz, Mainz, Germany
- *Correspondence: Sven Danckwardt,
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9
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Hao C, Zheng Y, Jönsson J, Cui X, Yu H, Wu C, Kajitani N, Schwartz S. hnRNP G/RBMX enhances HPV16 E2 mRNA splicing through a novel splicing enhancer and inhibits production of spliced E7 oncogene mRNAs. Nucleic Acids Res 2022; 50:3867-3891. [PMID: 35357488 PMCID: PMC9023273 DOI: 10.1093/nar/gkac213] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 11/23/2021] [Revised: 03/11/2022] [Accepted: 03/18/2022] [Indexed: 12/27/2022] Open
Abstract
Human papillomavirus type 16 (HPV16) E2 is an essential HPV16 protein. We have investigated how HPV16 E2 expression is regulated and have identifed a splicing enhancer that is required for production of HPV16 E2 mRNAs. This uridine-less splicing enhancer sequence (ACGAGGACGAGGACAAGGA) contains 84% adenosine and guanosine and 16% cytosine and consists of three ‘AC(A/G)AGG’-repeats. Mutational inactivation of the splicing enhancer reduced splicing to E2-mRNA specific splice site SA2709 and resulted in increased levels of unspliced E1-encoding mRNAs. The splicing enhancer sequence interacted with cellular RNA binding protein hnRNP G that promoted splicing to SA2709 and enhanced E2 mRNA production. The splicing-enhancing function of hnRNP G mapped to amino acids 236–286 of hnRNP G that were also shown to interact with splicing factor U2AF65. The interactions between hnRNP G and HPV16 E2 mRNAs and U2AF65 increased in response to keratinocyte differentiation as well as by the induction of the DNA damage response (DDR). The DDR reduced sumoylation of hnRNP G and pharmacological inhibition of sumoylation enhanced HPV16 E2 mRNA splicing and interactions between hnRNP G and E2 mRNAs and U2AF65. Intriguingly, hnRNP G also promoted intron retention of the HPV16 E6 coding region thereby inhibiting production of spliced E7 oncogene mRNAs.
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Affiliation(s)
- Chengyu Hao
- Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
| | - Yunji Zheng
- Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden.,School of Pharmacy, Binzhou Medical University, 264003 Yantai, China
| | - Johanna Jönsson
- Department of Medical Biochemistry and Microbiology (IMBIM), Uppsala University, BMC-B9, 751 23 Uppsala, Sweden.,Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
| | - Xiaoxu Cui
- Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
| | - Haoran Yu
- Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
| | - Chengjun Wu
- School of Biomedical Engineering, Dalian University of Technology, Liaoning IC Technology Key Lab, 116024 Dalian, China
| | - Naoko Kajitani
- Department of Medical Biochemistry and Microbiology (IMBIM), Uppsala University, BMC-B9, 751 23 Uppsala, Sweden.,Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
| | - Stefan Schwartz
- Department of Medical Biochemistry and Microbiology (IMBIM), Uppsala University, BMC-B9, 751 23 Uppsala, Sweden.,Department of Laboratory Medicine, Lund University, BMC-B13, 221 84 Lund, Sweden
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10
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Van Syoc E, Albeke SE, Scasta JD, van Diepen LT. Quantifying the immediate response of the soil microbial community to different grazing intensities on irrigated pastures. Agric Ecosyst Environ 2022; 326:107805. [PMID: 35068628 PMCID: PMC8782393 DOI: 10.1016/j.agee.2021.107805] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Grazing is known to affect soil microbial communities, nutrient cycling, and forage quantity and quality over time. However, a paucity of information exists for the immediate changes in the soil physicochemical and microbial environment in response to different grazing strategies. Soil microbes drive nutrient cycling and are involved in plant-soil-microbe relationships, making them potentially vulnerable to plant-driven changes in the soil environment caused by grazing. To test the hypothesis that variable grazing intensities modulate immediate effects on the soil microbial community, we conducted a grazing trial of three management approaches; high-intensity, short-duration grazing (HDG), low-intensity, medium-duration grazing (LDG), and no grazing (NG). Soil and vegetation samples were collected before grazing and 24 hours, 1 week, and 4 weeks after HDG grazing ended. Soil labile carbon (C) and nitrogen (N) pools, vegetation biomass, and soil microbial diversity and functional traits were determined, including extracellular enzymatic assays and high-throughput sequencing of the bacterial 16S rRNA and fungal ITS2 regions. We found that labile soil C and inorganic N increased following the LDG grazing while C-cycling extracellular enzymatic activities increased in response to HDG grazing but both total extracellular enzymatic activity profiles and soil abiotic profiles were mostly affected by temporal fluxes. The soil fungal community composition was strongly affected by the interaction of sampling time and grazing treatment, while the soil bacterial community composition was largely affected by sampling time with a lesser impact from grazing treatment. We identified several key fungal taxa that may influence immediate responses to grazing and modulate plant-soil-microbe interactions. There was strong evidence of temporal influences on soil biogeochemical variables and the soil microbiome, even within our narrow sampling scheme. Our results indicate that the soil ecosystem is dynamic and responsive to different grazing strategies within very short time scales, showing the need for further research to understand plant-soil-microbe interactions and how these feedback mechanisms can inform sustainable land management.
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Affiliation(s)
- Emily Van Syoc
- Department of Ecosystem Science and Management, University of Wyoming, Wyoming, USA
- Integrative & Biomedical Physiology and Clinical & Translational Sciences Dual-Title Ph.D. Program, The Pennsylvania State University, Pennsylvania, USA
| | - Shannon E. Albeke
- Wyoming Geographic Information Science Center, University of Wyoming, Wyoming, USA
| | - John Derek Scasta
- Department of Ecosystem Science and Management, University of Wyoming, Wyoming, USA
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11
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Cui X, Nilsson K, Kajitani N, Schwartz S. Overexpression of m6A-factors METTL3, ALKBH5, and YTHDC1 alters HPV16 mRNA splicing. Virus Genes 2022. [PMID: 35190939 DOI: 10.1007/s11262-022-01889-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/12/2022] [Indexed: 11/24/2022]
Abstract
We report that overexpression of the m6A-demethylase alkB homolog 5 RNA demethylase (ALKBH5) promoted production of intron retention on the human papillomavirus type 16 (HPV16) E6 mRNAs thereby promoting E6 mRNA production. ALKBH5 also altered alternative splicing of the late L1 mRNA by an exon skipping mechanism. Knock-down of ALKBH5 had the opposite effect on splicing of these HPV16 mRNAs. Overexpression of the m6A-methylase methyltransferase-like protein 3 (METLL3) induced production of intron-containing HPV16 E1 mRNAs over spliced E2 mRNAs and altered HPV16 L1 mRNA splicing in a manner opposite to ALKBH5. Overexpression of the nuclear m6A-“reader” YTH domain-containing protein 1 (YTHDC1), enhanced retention of the E6-encoding intron and promoted E6 mRNA production. We also show that HPV16 mRNAs are bound to YTHDC1 in human cells and that YTHDC1 affected splicing of HPV16 E6/E7 mRNAs produced from the episomal form of the HPV16 genome. Finally, we show that HPV16 mRNAs are m6A-methylated in tonsillar cancer cells. In summary, HPV16 mRNAs are methylated in HPV16-infected tonsillar cancer cells and overexpression of m6A-“writer” METTL3, m6A-“eraser” ALKBH5 and the m6A-“reader” YTHDC1 affected HPV16 mRNA splicing, suggesting that m6A plays an important role in the HPV16 gene expression program, at least in cancer cells.
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12
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Lu S, Gao C, Wang Y, He Y, Du J, Chen M, Zhao H, Fang H, Wang B, Cao Y. Phylogenetic Analysis of the Plant U2 snRNP Auxiliary Factor Large Subunit A Gene Family in Response to Developmental Cues and Environmental Stimuli. Front Plant Sci 2021; 12:739671. [PMID: 34868124 PMCID: PMC8635922 DOI: 10.3389/fpls.2021.739671] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2021] [Accepted: 10/22/2021] [Indexed: 06/13/2023]
Abstract
In all organisms, splicing occurs through the formation of spliceosome complexes, and splicing auxiliary factors are essential during splicing. U2AF65 is a crucial splicing cofactor, and the two typical RNA-recognition motifs at its center recognize and bind the polypyrimidine sequence located between the intron branch site and the 3'-splice site. U2AF65A is a member of the U2AF65 gene family, with pivotal roles in diseases in mammals, specifically humans; however, few studies have investigated plant U2AF65A, and its specific functions are poorly understood. Therefore, in the present study, we systematically identified U2AF65A in plant species from algae to angiosperms. Based on 113 putative U2AF65A sequences from 33 plant species, phylogenetic analyses were performed, followed by basic bioinformatics, including the comparisons of gene structure, protein domains, promoter motifs, and gene expression levels. In addition, using rice as the model crop, we demonstrated that the OsU2AF65A protein is localized to the nucleus and cytoplasm, and it is involved in responses to various stresses, such as drought, high salinity, low temperature, and heavy metal exposure (e.g., cadmium). Using Arabidopsis thaliana and rice mutants, we demonstrated that U2AF65A is involved in the accumulation of plant biomass, growth of hypocotyl upon thermal stimulation, and reduction of tolerance of high temperature stress. These findings offer an overview of the U2AF65 gene family and its stress response functions, serving as the reference for further comprehensive functional studies of the essential specific splicing cofactor U2AF65A in the plant kingdom.
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Affiliation(s)
- Shuai Lu
- School of Life Sciences, Nantong University, Nantong, China
| | - Cong Gao
- School of Life Sciences, Nantong University, Nantong, China
| | - Yongzhou Wang
- School of Life Sciences, Nantong University, Nantong, China
| | - Yingying He
- School of Life Sciences, Nantong University, Nantong, China
| | - Junrong Du
- School of Life Sciences, Nantong University, Nantong, China
| | - Moxian Chen
- CAS Key Laboratory of Quantitative Engineering Biology, Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Hua Zhao
- School of Life Sciences, Nantong University, Nantong, China
| | - Hui Fang
- School of Life Sciences, Nantong University, Nantong, China
| | - Baohua Wang
- School of Life Sciences, Nantong University, Nantong, China
| | - Yunying Cao
- School of Life Sciences, Nantong University, Nantong, China
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13
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Dutertre M, Sfaxi R, Vagner S. Reciprocal Links between Pre-messenger RNA 3'-End Processing and Genome Stability. Trends Biochem Sci 2021; 46:579-594. [PMID: 33653631 DOI: 10.1016/j.tibs.2021.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 01/11/2021] [Accepted: 01/22/2021] [Indexed: 02/07/2023]
Abstract
The 3'-end processing of most pre-messenger RNAs (pre-mRNAs) involves RNA cleavage and polyadenylation and is coupled to transcription termination. In both yeast and human cells, pre-mRNA 3'-end cleavage is globally inhibited by DNA damage. Recently, further links between pre-mRNA 3'-end processing and the control of genome stability have been uncovered, as reviewed here. Upon DNA damage, various genes related to the DNA damage response (DDR) escape 3'-end processing inhibition or are regulated through alternative polyadenylation (APA). Conversely, various pre-mRNA 3'-end processing factors prevent genome instability and are found at sites of DNA damage. Finally, the reciprocal link between pre-mRNA 3'-end processing and genome stability control seems important because it is conserved in evolution and involved in disease development.
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Affiliation(s)
- Martin Dutertre
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer.
| | - Rym Sfaxi
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer
| | - Stéphan Vagner
- Institut Curie, Université PSL, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3348, INSERM U1278, 91400 Orsay, France; Equipe Labellisée Ligue Nationale Contre le Cancer.
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14
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von Witzleben A, Currall E, Wood O, Chudley L, Akinyegun O, Thomas J, Bendjama K, Thomas GJ, Friedmann PS, King EV, Laban S, Ottensmeier CH. Correlation of HPV16 Gene Status and Gene Expression With Antibody Seropositivity and TIL Status in OPSCC. Front Oncol 2021; 10:591063. [PMID: 33575210 PMCID: PMC7871909 DOI: 10.3389/fonc.2020.591063] [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] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 11/02/2020] [Indexed: 12/09/2022] Open
Abstract
INTRODUCTION Human papillomavirus 16 (HPV16) is the main cause of oropharyngeal squamous cell carcinoma (OPSCC). To date, the links between HPV16 gene expression and adaptive immune responses have not been investigated. We evaluated the correlation of HPV16 DNA, RNA transcripts and features of adaptive immune response by evaluating antibody isotypes against E2, E7 antigens and density of tumor-infiltrating lymphocytes (TIL). MATERIAL AND METHODS FFPE-tissue from 27/77 p16-positive OPSCC patients was available. DNA and RNA were extracted and quantified using qPCR for all HPV16 genes. The TIL status was assessed. Immune responses against E2 and E7 were quantified by ELISA (IgG, IgA, and IgM; 77 serum samples pre-treatment, 36 matched post-treatment). RESULTS Amounts of HPV16 genes were highly correlated at DNA and RNA levels. RNA co-expression of all genes was detected in 37% (7/19). E7 qPCR results were correlated with higher anti-E7 antibody (IgG, IgA) level in the blood. Patients with high anti-E2 IgG antibody (>median) had better overall survival (p=0.0311); anti-E2 and anti-E7 IgA levels had no detectable effect. During the first 6 months after treatment, IgA but not IgG increased significantly, and >6 months both antibody classes declined over time. Patients with immune cell-rich tumors had higher levels of circulating antibodies against HPV antigens. CONCLUSION We describe an HPV16 qPCR assay to quantify genomic and transcriptomic expression and correlate this with serum antibody levels against HPV16 oncoproteins. Understanding DNA/RNA expression, relationship to the antibody response in patients regarding treatment and outcome offers an attractive tool to improve patient care.
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Affiliation(s)
- Adrian von Witzleben
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Department of Otorhinolaryngology, Head & Neck Surgery, University of Ulm, Ulm, Germany
| | - Eve Currall
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Oliver Wood
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Lindsey Chudley
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Oluyemisi Akinyegun
- Southampton University Hospitals NHS Foundation Trust, Southampton, United Kingdom
| | - Jaya Thomas
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Kaïdre Bendjama
- Department Affaires Médicinales, Research, Project, Transgene SA, Illkirch, France
| | - Gareth J. Thomas
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Southampton University Hospitals NHS Foundation Trust, Southampton, United Kingdom
| | - Peter S. Friedmann
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Emma V. King
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Department of Otorhinolaryngology, Head & Neck Surgery, Poole Hospital, Poole, United Kingdom
| | - Simon Laban
- Department of Otorhinolaryngology, Head & Neck Surgery, University of Ulm, Ulm, Germany
| | - Christian H. Ottensmeier
- CRUK and NIHR Experimental Cancer Medicine Center & School of Cancer Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
- Liverpool Head and Neck Centre, Institute of Translational Medicine, Department of Molecular & Clinical Cancer Medicine, University of Liverpool, Liverpool, United Kingdom
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15
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Lash CL, Fordyce JA, Kwit C. Nest substrate, more than ant activity, drives fungal pathogen community dissimilarity in seed-dispersing ant nests. Oecologia 2020; 194:649-657. [PMID: 33159541 DOI: 10.1007/s00442-020-04796-5] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Accepted: 10/24/2020] [Indexed: 11/30/2022]
Abstract
Myrmecochory is a widespread mutualism in which plants benefit from seed dispersal services by ants. Ants might also be providing seeds with an additional byproduct benefit via reduced plant pathogen loads in the ant nest environment through their antimicrobial glandular secretions. We investigate this byproduct benefit by identifying fungal communities in ant nests and surrounding environments and quantifying fungal community change (1) through time, (2) between different nest substrates, and (3) as a function of average ant activity levels within nests (based on observed ant activity at nest entrances throughout the summer). We split fungal communities by functional guild to determine seed-dispersing ant-induced changes in the overall fungal community, the animal pathogen fungal community, the plant pathogen fungal community, and the myrmecochore pathogen fungal community. Nest substrate (soil or log) explained much of the variation in fungal community dissimilarity, while substrate occupation (ant nest or control sample) and time had no influence on fungal community composition. Average ant activity had no effect on the community turnover in fungal communities except for the myrmecochore pathogenic fungal community. In this community, higher ant activity throughout the summer resulted in more fluctuation in the pathogenic community in the ant nest. Our results are not consistent with a byproduct benefit framework in myrmecochory, but suggest that nest substrate drives dissimilarity in fungal communities. The influence of nest substrate on fungal communities has important implications for seeds taken into ant nests, as well as ant nest location choice by queens and during nest relocation.
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Affiliation(s)
- Chloe L Lash
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA. .,Natural Sciences Department, University of St. Francis, Joliet, IL, 60435, USA.
| | - James A Fordyce
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA
| | - Charles Kwit
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN, 37996, USA.,Department of Forestry, Wildlife and Fisheries, University of Tennessee, Knoxville, TN, 37996, USA
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Kajitani N, Schwartz S. Role of Viral Ribonucleoproteins in Human Papillomavirus Type 16 Gene Expression. Viruses 2020; 12:E1110. [PMID: 33007936 DOI: 10.3390/v12101110] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 09/25/2020] [Accepted: 09/26/2020] [Indexed: 02/06/2023] Open
Abstract
Human papillomaviruses (HPVs) depend on the cellular RNA-processing machineries including alternative RNA splicing and polyadenylation to coordinate HPV gene expression. HPV RNA processing is controlled by cis-regulatory RNA elements and trans-regulatory factors since the HPV splice sites are suboptimal. The definition of HPV exons and introns may differ between individual HPV mRNA species and is complicated by the fact that many HPV protein-coding sequences overlap. The formation of HPV ribonucleoproteins consisting of HPV pre-mRNAs and multiple cellular RNA-binding proteins may result in the different outcomes of HPV gene expression, which contributes to the HPV life cycle progression and HPV-associated cancer development. In this review, we summarize the regulation of HPV16 gene expression at the level of RNA processing with focus on the interactions between HPV16 pre-mRNAs and cellular RNA-binding factors.
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Zheng Y, Jönsson J, Hao C, Shoja Chaghervand S, Cui X, Kajitani N, Gong L, Wu C, Schwartz S. Heterogeneous Nuclear Ribonucleoprotein A1 (hnRNP A1) and hnRNP A2 Inhibit Splicing to Human Papillomavirus 16 Splice Site SA409 through a UAG-Containing Sequence in the E7 Coding Region. J Virol 2020; 94:e01509-20. [PMID: 32759322 DOI: 10.1128/JVI.01509-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 07/31/2020] [Indexed: 02/06/2023] Open
Abstract
Human papillomavirus type 16 (HPV16) belongs to the high-risk-group of HPVs and is causing a variety of anogenital cancers and head and neck cancer. The two HPV16 oncoproteins E6 and E7 prevent apoptosis and promote mitosis and are essential for completion of the HPV16 life cycle and for transformation of the infected cell and maintenance of malignancy. E6 and E7 are produced from two mRNAs that are generated in a mutually exclusive manner by alternative splicing. While E6 protein is made from the unspliced mRNA, E7 is made from the spliced version of the same pre-mRNA. Since sufficient quantities of both E6 and E7 are required for malignant transformation, this intricate arrangement of gene expression renders E6 and E7 expression vulnerable to external interference. Since antiviral drugs to HPV16 are not available, a detailed knowledge of the regulation of HPV16 E6 and E7 mRNA splicing may uncover novel targets for therapy. Human papillomavirus 16 (HPV16) 5′-splice site SD226 and 3′-splice site SA409 are required for production of the HPV16 E7 mRNAs, whereas unspliced mRNAs produce E6 mRNAs. The E6 and E7 proteins are essential in the HPV16 replication cycle but are also the major HPV16 proteins required for induction and maintenance of malignancy caused by HPV16 infection. Thus, a balanced expression of unspliced and spliced mRNAs is required for production of sufficient quantities of E6 and E7 proteins under physiological and pathophysiological conditions. If splicing becomes too efficient, the levels of unspliced E6 mRNAs will decrease below a threshold level that is no longer able to produce E6 protein quantities high enough to significantly reduce p53 protein levels. Similarly, if splicing becomes too inefficient, the levels of spliced E7 mRNAs will decrease below a threshold level that is no longer able to produce E7 protein quantities high enough to significantly reduce pRb protein levels. To determine how splicing between SD226 and SA409 is regulated, we have investigated how SA409 is controlled by the cellular proteins hnRNP A1 and hnRNP A2, two proteins that have been shown previously to control HPV16 gene expression. We found that hnRNP A1 and A2 interacted directly and specifically with a C-less RNA element located between HPV16 nucleotide positions 594 and 604 downstream of SA409. Overexpression of hnRNP A1 inhibited SA409 and promoted production of unspliced E6 mRNAs at the expense of the E7 mRNAs, whereas overexpression of hnRNP A2 inhibited SA409 to redirect splicing to SA742, a downstream 3′-splice site that is used for generation of HPV16 E6̂E7, E1, and E4 mRNAs. Thus, high levels of either hnRNP A1 or hnRNP A2 inhibited production of the promitotic HPV16 E7 protein. We show that the hnRNP A1 and A2 proteins control the relative levels of the HPV16 unspliced and spliced HPV16 E6 and E7 mRNAs and function as inhibitors of HPV16 E7 expression. IMPORTANCE Human papillomavirus type 16 (HPV16) belongs to the high-risk-group of HPVs and is causing a variety of anogenital cancers and head and neck cancer. The two HPV16 oncoproteins E6 and E7 prevent apoptosis and promote mitosis and are essential for completion of the HPV16 life cycle and for transformation of the infected cell and maintenance of malignancy. E6 and E7 are produced from two mRNAs that are generated in a mutually exclusive manner by alternative splicing. While E6 protein is made from the unspliced mRNA, E7 is made from the spliced version of the same pre-mRNA. Since sufficient quantities of both E6 and E7 are required for malignant transformation, this intricate arrangement of gene expression renders E6 and E7 expression vulnerable to external interference. Since antiviral drugs to HPV16 are not available, a detailed knowledge of the regulation of HPV16 E6 and E7 mRNA splicing may uncover novel targets for therapy.
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18
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Nilsson K, Abdurahman S, Schwartz S. Influenza virus natural sequence heterogeneity in segment 8 affects interactions with cellular RNA-binding proteins and splicing efficiency. Virology 2020; 549:39-50. [PMID: 32829114 DOI: 10.1016/j.virol.2020.08.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 11/18/2022]
Abstract
Segment 8 mRNAs of influenza virus A/Brevig Misson/1918/1 (H1N1) are poorly spliced compared to segment 8 mRNAs of influenza virus A/Netherlands/178/95 (H3N2). Using oligonucleotide-mediated protein pull down with oligos spanning the entire length of segment 8 of either influenza virus H1N1 or influenza virus H3N2 we identified cellular RNA binding proteins that interacted with oligonucleotides derived from either H1N1 or H3N2 sequences. When the identified hot spots for RNA binding proteins in H1N1 segment 8 mRNAs were replaced by H3N2 sequences, splicing efficiency increased significantly. Replacing as few as three nucleotides of the H1N1 mRNA with sequences from H3N2 mRNA, enhanced splicing of the H1N1 mRNAs. Cellular proteins U2AF65 and HuR interacted preferentially with the 3'-splice site of H3N2 and overexpression of HuR reduced the levels of unspliced H1N1 mRNAs, suggesting that U2AF65 and HuR contribute to control of influenza virus mRNA splicing.
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MESH Headings
- A549 Cells
- Alternative Splicing
- ELAV-Like Protein 1/genetics
- ELAV-Like Protein 1/metabolism
- Genetic Variation
- HeLa Cells
- Host-Pathogen Interactions/genetics
- Humans
- Influenza A Virus, H1N1 Subtype/genetics
- Influenza A Virus, H1N1 Subtype/metabolism
- Influenza A Virus, H3N2 Subtype/genetics
- Influenza A Virus, H3N2 Subtype/metabolism
- Oligonucleotides/chemistry
- Oligonucleotides/metabolism
- Plasmids/chemistry
- Plasmids/metabolism
- Protein Binding
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Viral/chemistry
- RNA, Viral/genetics
- RNA, Viral/metabolism
- Splicing Factor U2AF/genetics
- Splicing Factor U2AF/metabolism
- Transfection
- Viral Nonstructural Proteins/genetics
- Viral Nonstructural Proteins/metabolism
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Affiliation(s)
- Kersti Nilsson
- Department of Laboratory Medicine, BMC-B13, Lund University, 221 84, Lund, Sweden
| | - Samir Abdurahman
- Department of Science and Technology, Örebro University, 701 82, Örebro, Sweden
| | - Stefan Schwartz
- Department of Laboratory Medicine, BMC-B13, Lund University, 221 84, Lund, Sweden.
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19
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Cerasuolo A, Buonaguro L, Buonaguro FM, Tornesello ML. The Role of RNA Splicing Factors in Cancer: Regulation of Viral and Human Gene Expression in Human Papillomavirus-Related Cervical Cancer. Front Cell Dev Biol 2020; 8:474. [PMID: 32596243 PMCID: PMC7303290 DOI: 10.3389/fcell.2020.00474] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [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: 03/24/2020] [Accepted: 05/20/2020] [Indexed: 12/12/2022] Open
Abstract
The spliceosomal complex components, together with the heterogeneous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich (SR) proteins, regulate the process of constitutive and alternative splicing, the latter leading to the production of mRNA isoforms coding multiple proteins from a single pre-mRNA molecule. The expression of splicing factors is frequently deregulated in different cancer types causing the generation of oncogenic proteins involved in cancer hallmarks. Cervical cancer is caused by persistent infection with oncogenic human papillomaviruses (HPVs) and constitutive expression of viral oncogenes. The aberrant activity of hnRNPs and SR proteins in cervical neoplasia has been shown to trigger the production of oncoproteins through the processing of pre-mRNA transcripts either derived from human genes or HPV genomes. Indeed, hnRNP and SR splicing factors have been shown to regulate the production of viral oncoprotein isoforms necessary for the completion of viral life cycle and for cell transformation. Target-therapy strategies against hnRNPs and SR proteins, causing simultaneous reduction of oncogenic factors and inhibition of HPV replication, are under development. In this review, we describe the current knowledge of the functional link between RNA splicing factors and deregulated cellular as well as viral RNA maturation in cervical cancer and the opportunity of new therapeutic strategies.
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Affiliation(s)
| | | | | | - Maria Lina Tornesello
- Molecular Biology and Viral Oncology Unit, Istituto Nazionale Tumouri IRCCS–Fondazione G. Pascale, Naples, Italy
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20
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Gautam D, Johnson BA, Mac M, Moody CA. SETD2-dependent H3K36me3 plays a critical role in epigenetic regulation of the HPV31 life cycle. PLoS Pathog 2018; 14:e1007367. [PMID: 30312361 PMCID: PMC6200281 DOI: 10.1371/journal.ppat.1007367] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 10/24/2018] [Accepted: 09/28/2018] [Indexed: 12/14/2022] Open
Abstract
The life cycle of HPV is tied to the differentiation status of its host cell, with productive replication, late gene expression and virion production restricted to the uppermost layers of the stratified epithelium. HPV DNA is histone-associated, exhibiting a chromatin structure similar to that of the host chromosome. Although HPV chromatin is subject to histone post-translational modifications, how the viral life cycle is epigenetically regulated is not well understood. SETD2 is a histone methyltransferase that places the trimethyl mark on H3K36 (H3K36me3), a mark of active transcription. Here, we define a role for SETD2 and H3K36me3 in the viral life cycle. We have found that HPV positive cells exhibit increased levels of SETD2, with SETD2 depletion leading to defects in productive viral replication and splicing of late viral RNAs. Reducing H3K36me3 by overexpression of KDM4A, an H3K36me3 demethylase, or an H3.3K36M transgene also blocks productive viral replication, indicating a significant role for this histone modification in facilitating viral processes. H3K36me3 is enriched on the 3' end of the early region of the high-risk HPV31 genome in a SETD2-dependent manner, suggesting that SETD2 may regulate the viral life cycle through the recruitment of H3K36me3 readers to viral DNA. Intriguingly, we have found that activation of the ATM DNA damage kinase, which is required for productive viral replication, is necessary for the maintenance of H3K36me3 on viral chromatin and for processing of late viral RNAs. Additionally, we have found that the HPV31 E7 protein maintains the increased SETD2 levels in infected cells through an extension of protein half-life. Collectively, our findings highlight the importance of epigenetic modifications in driving the viral life cycle and identify a novel role for E7 as well as the DNA damage response in the regulation of viral processes through epigenetic modifications.
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Affiliation(s)
- Dipendra Gautam
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Bryan A. Johnson
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Michelle Mac
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Cary A. Moody
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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21
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Nilsson K, Wu C, Schwartz S. Role of the DNA Damage Response in Human Papillomavirus RNA Splicing and Polyadenylation. Int J Mol Sci 2018; 19:E1735. [PMID: 29895741 PMCID: PMC6032147 DOI: 10.3390/ijms19061735] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 05/07/2018] [Revised: 05/29/2018] [Accepted: 06/08/2018] [Indexed: 12/16/2022] Open
Abstract
Human papillomaviruses (HPVs) have evolved to use the DNA repair machinery to replicate its DNA genome in differentiated cells. HPV activates the DNA damage response (DDR) in infected cells. Cellular DDR factors are recruited to the HPV DNA genome and position the cellular DNA polymerase on the HPV DNA and progeny genomes are synthesized. Following HPV DNA replication, HPV late gene expression is activated. Recent research has shown that the DDR factors also interact with RNA binding proteins and affects RNA processing. DDR factors activated by DNA damage and that associate with HPV DNA can recruit splicing factors and RNA binding proteins to the HPV DNA and induce HPV late gene expression. This induction is the result of altered alternative polyadenylation and splicing of HPV messenger RNA (mRNA). HPV uses the DDR machinery to replicate its DNA genome and to activate HPV late gene expression at the level of RNA processing.
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Affiliation(s)
- Kersti Nilsson
- Department of Laboratory Medicine, Lund University, 221 84 Lund, Sweden.
| | - Chengjun Wu
- Department of Laboratory Medicine, Lund University, 221 84 Lund, Sweden.
| | - Stefan Schwartz
- Department of Laboratory Medicine, Lund University, 221 84 Lund, Sweden.
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