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Li D, Yu W, Lai M. Targeting serine- and arginine-rich splicing factors to rectify aberrant alternative splicing. Drug Discov Today 2023; 28:103691. [PMID: 37385370 DOI: 10.1016/j.drudis.2023.103691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/30/2023] [Accepted: 06/21/2023] [Indexed: 07/01/2023]
Abstract
Serine- and arginine-rich splicing factors are pivotal modulators of constitutive splicing and alternative splicing that bind to the cis-acting elements in precursor mRNAs and facilitate the recruitment and assembly of the spliceosome. Meanwhile, SR proteins shuttle between the nucleus and cytoplasm with a broad implication in multiple RNA-metabolizing events. Recent studies have demonstrated the positive correlation of overexpression and/or hyperactivation of SR proteins and development of the tumorous phenotype, indicating the therapeutic potentials of targeting SR proteins. In this review, we highlight key findings concerning the physiological and pathological roles of SR proteins. We have also investigated small molecules and oligonucleotides that effectively modulate the functions of SR proteins, which could benefit future studies of SR proteins.
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Affiliation(s)
- Dianyang Li
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China.
| | - Wenying Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
| | - Maode Lai
- Department of Pharmacology, China Pharmaceutical University, Nanjing 210009, China; Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy, Chinese Academy of Medical Science (2019RU042), Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, Zhejiang, China.
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2
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Li D, Yu W, Lai M. Towards understandings of serine/arginine-rich splicing factors. Acta Pharm Sin B 2023; 13:3181-3207. [PMID: 37655328 PMCID: PMC10465970 DOI: 10.1016/j.apsb.2023.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/13/2023] [Accepted: 05/06/2023] [Indexed: 09/02/2023] Open
Abstract
Serine/arginine-rich splicing factors (SRSFs) refer to twelve RNA-binding proteins which regulate splice site recognition and spliceosome assembly during precursor messenger RNA splicing. SRSFs also participate in other RNA metabolic events, such as transcription, translation and nonsense-mediated decay, during their shuttling between nucleus and cytoplasm, making them indispensable for genome diversity and cellular activity. Of note, aberrant SRSF expression and/or mutations elicit fallacies in gene splicing, leading to the generation of pathogenic gene and protein isoforms, which highlights the therapeutic potential of targeting SRSF to treat diseases. In this review, we updated current understanding of SRSF structures and functions in RNA metabolism. Next, we analyzed SRSF-induced aberrant gene expression and their pathogenic outcomes in cancers and non-tumor diseases. The development of some well-characterized SRSF inhibitors was discussed in detail. We hope this review will contribute to future studies of SRSF functions and drug development targeting SRSFs.
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Affiliation(s)
- Dianyang Li
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Wenying Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Maode Lai
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy, Chinese Academy of Medical Science (2019RU042), Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China
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3
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Jia R, Zheng ZM. Oncogenic SRSF3 in health and diseases. Int J Biol Sci 2023; 19:3057-3076. [PMID: 37416784 PMCID: PMC10321290 DOI: 10.7150/ijbs.83368] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 05/30/2023] [Indexed: 07/08/2023] Open
Abstract
Serine/arginine rich splicing factor 3 (SRSF3) is an important multi-functional splicing factor, and has attracted increasing attentions in the past thirty years. The importance of SRSF3 is evidenced by its impressively conserved protein sequences in all animals and alternative exon 4 which represents an autoregulatory mechanism to maintain its proper cellular expression level. New functions of SRSF3 have been continuously discovered recently, especially its oncogenic function. SRSF3 plays essential roles in many cellular processes by regulating almost all aspects of RNA biogenesis and processing of many target genes, and thus, contributes to tumorigenesis when overexpressed or disregulated. This review updates and highlights the gene, mRNA, and protein structure of SRSF3, the regulatory mechanisms of SRSF3 expression, and the characteristics of SRSF3 targets and binding sequences that contribute to SRSF3's diverse molecular and cellular functions in tumorigenesis and human diseases.
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Affiliation(s)
- Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology & Key Laboratory of Oral Biomedicine Ministry of Education, School & Hospital of Stomatology, Wuhan University, Wuhan, Hubei, China
| | - Zhi-Ming Zheng
- Tumor Virus RNA Biology Section, HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, Maryland, USA
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4
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Zheng K, Ren Z, Wang Y. Serine-arginine protein kinases and their targets in viral infection and their inhibition. Cell Mol Life Sci 2023; 80:153. [PMID: 37198350 PMCID: PMC10191411 DOI: 10.1007/s00018-023-04808-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/10/2023] [Accepted: 05/12/2023] [Indexed: 05/19/2023]
Abstract
Accumulating evidence has consolidated the interaction between viral infection and host alternative splicing. Serine-arginine (SR) proteins are a class of highly conserved splicing factors critical for the spliceosome maturation, alternative splicing and RNA metabolism. Serine-arginine protein kinases (SRPKs) are important kinases that specifically phosphorylate SR proteins to regulate their distribution and activities in the central pre-mRNA splicing and other cellular processes. In addition to the predominant SR proteins, other cytoplasmic proteins containing a serine-arginine repeat domain, including viral proteins, have been identified as substrates of SRPKs. Viral infection triggers a myriad of cellular events in the host and it is therefore not surprising that viruses explore SRPKs-mediated phosphorylation as an important regulatory node in virus-host interactions. In this review, we briefly summarize the regulation and biological function of SRPKs, highlighting their involvement in the infection process of several viruses, such as viral replication, transcription and capsid assembly. In addition, we review the structure-function relationships of currently available inhibitors of SRPKs and discuss their putative use as antivirals against well-characterized viruses or newly emerging viruses. We also highlight the viral proteins and cellular substrates targeted by SRPKs as potential antiviral therapeutic candidates.
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Affiliation(s)
- Kai Zheng
- School of Pharmacy, Shenzhen University Medical School, Shenzhen, 518055, China.
| | - Zhe Ren
- Institute of Biomedicine, College of Life Science and Technology, Guangdong Province Key Laboratory of Bioengineering Medicine, Key Laboratory of Innovative Technology Research On Natural Products and Cosmetics Raw Materials, Jinan University, Guangzhou, 510632, China
| | - Yifei Wang
- Institute of Biomedicine, College of Life Science and Technology, Guangdong Province Key Laboratory of Bioengineering Medicine, Key Laboratory of Innovative Technology Research On Natural Products and Cosmetics Raw Materials, Jinan University, Guangzhou, 510632, China
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5
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Xue J, Ma T, Zhang X. TRA2: The dominant power of alternative splicing in tumors. Heliyon 2023; 9:e15516. [PMID: 37151663 PMCID: PMC10161706 DOI: 10.1016/j.heliyon.2023.e15516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/30/2023] [Accepted: 04/12/2023] [Indexed: 05/09/2023] Open
Abstract
The dysregulation of alternative splicing (AS) is frequently found in cancer and considered as key markers for cancer progression and therapy. Transformer 2 (TRA2), a nuclear RNA binding protein, consists of transformer 2 alpha homolog (TRA2A) and transformer 2 beta homolog (TRA2B), and plays a role in the regulation of pre-mRNA splicing. Growing evidence has been provided that TRA2A and TRA2B are dysregulated in several types of tumors, and participate in the regulation of proliferation, migration, invasion, and chemotherapy resistance in cancer cells through alteration of AS of cancer-related genes. In this review, we highlight the role of TRA2 in tumorigenesis and metastasis, and discuss potential molecular mechanisms how TRA2 influences tumorigenesis and metastasis via controlling AS of pre-mRNA. We propose that TRA2Ais a novel biomarker and therapeutic target for cancer progression and therapy.
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Affiliation(s)
- Jiancheng Xue
- Medical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
- Key Laboratory of Research and Application of Animal Model for Environmental and Metabolic Diseases, Shenyang, China
| | - Tie Ma
- Department of Pathology, Shengjing Hospital of China Medical University, Shenyang, China
- Corresponding author.
| | - Xiaowen Zhang
- Medical Research Center, Shengjing Hospital of China Medical University, Shenyang, China
- Key Laboratory of Research and Application of Animal Model for Environmental and Metabolic Diseases, Shenyang, China
- Corresponding author. Medical Research Center, Shengjing Hospital of China Medical University, #36 Sanhao Street, Heping District, Shenyang, 110004, China.
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6
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Li Y, Wang T, Liao Q, Luo X, Wang X, Zeng S, You M, Chen Y, Ruan XZ. Loss of Splicing Factor SRSF3 Impairs Lipophagy Through Ubiquitination and Degradation of Syntaxin17 in Hepatocytes. J Lipid Res 2023; 64:100342. [PMID: 36764525 PMCID: PMC10020108 DOI: 10.1016/j.jlr.2023.100342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 01/11/2023] [Accepted: 01/12/2023] [Indexed: 02/10/2023] Open
Abstract
Lipid accumulation in hepatocytes is the distinctive characteristic of nonalcoholic fatty liver disease. Serine/arginine-rich splicing factor 3 (SRSF3) is highly expressed in the liver and expression decreases in high-fat conditions. However, the role of SRSF3 in hepatic lipid metabolism needs to be clarified. Here, we showed that loss of SRSF3 was associated with lipid accumulation. We determined that SRSF3 regulated lipophagy, the process of selective degradation of lipid droplets by autophagy. Mechanistically, loss of SRSF3 impaired the fusion of the autophagosome and lysosome by promoting the proteasomal degradation of syntaxin 17 (STX17), a key autophagosomal SNARE protein. We found that ubiquitination of STX17 was increased and upregulation of seven in absentia homolog 1 was responsible for the increased posttranslational modification of STX17. Taken together, our data primarily demonstrate that loss of SRSF3 weakens the clearance of fatty acids by impairing lipophagy in the progression of nonalcoholic fatty liver disease, indicating a novel potential therapeutic target for fatty liver disease treatment.
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Affiliation(s)
- Yun Li
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Tao Wang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Qiumin Liao
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaoting Luo
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xing Wang
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Shu Zeng
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Mengyue You
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Yaxi Chen
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China.
| | - Xiong Z Ruan
- Centre for Lipid Research & Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), the Second Affiliated Hospital, Chongqing Medical University, Chongqing, China; John Moorhead Research Laboratory, Centre for Nephrology, University College London Medical School, Royal Free Campus, University College London, London, United Kingdom.
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7
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Characterization of alternative mRNA splicing in cultured cell populations representing progressive stages of human fetal kidney development. Sci Rep 2022; 12:19548. [PMID: 36380228 PMCID: PMC9666651 DOI: 10.1038/s41598-022-24147-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Nephrons are the functional units of the kidney. During kidney development, cells from the cap mesenchyme-a transient kidney-specific progenitor state-undergo a mesenchymal to epithelial transition (MET) and subsequently differentiate into the various epithelial cell types that create the tubular structures of the nephron. Faults in this transition can lead to a pediatric malignancy of the kidney called Wilms' tumor that mimics normal kidney development. While human kidney development has been characterized at the gene expression level, a comprehensive characterization of alternative splicing is lacking. Therefore, in this study, we performed RNA sequencing on cell populations representing early, intermediate, and late developmental stages of the human fetal kidney, as well as three blastemal-predominant Wilms' tumor patient-derived xenografts. Using this newly generated RNAseq data, we identified a set of transcripts that are alternatively spliced between the different developmental stages. Moreover, we found that cells from the earliest developmental stage have a mesenchymal splice-isoform profile that is similar to that of blastemal-predominant Wilms' tumor xenografts. RNA binding motif enrichment analysis suggests that the mRNA binding proteins ESRP1, ESRP2, RBFOX2, and QKI regulate alternative mRNA splicing during human kidney development. These findings illuminate new molecular mechanisms involved in human kidney development and pediatric kidney cancer.
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Dahal S, Clayton K, Been T, Fernet-Brochu R, Ocando AV, Balachandran A, Poirier M, Maldonado RK, Shkreta L, Boligan KF, Guvenc F, Rahman F, Branch D, Bell B, Chabot B, Gray-Owen SD, Parent LJ, Cochrane A. Opposing roles of CLK SR kinases in controlling HIV-1 gene expression and latency. Retrovirology 2022; 19:18. [PMID: 35986377 PMCID: PMC9389714 DOI: 10.1186/s12977-022-00605-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 07/29/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND The generation of over 69 spliced HIV-1 mRNAs from one primary transcript by alternative RNA splicing emphasizes the central role that RNA processing plays in HIV-1 replication. Control is mediated in part through the action of host SR proteins whose activity is regulated by multiple SR kinases (CLK1-4, SRPKs). METHODS Both shRNA depletion and small molecule inhibitors of host SR kinases were used in T cell lines and primary cells to evaluate the role of these factors in the regulation of HIV-1 gene expression. Effects on virus expression were assessed using western blotting, RT-qPCR, and immunofluorescence. RESULTS The studies demonstrate that SR kinases play distinct roles; depletion of CLK1 enhanced HIV-1 gene expression, reduction of CLK2 or SRPK1 suppressed it, whereas CLK3 depletion had a modest impact. The opposing effects of CLK1 vs. CLK2 depletion were due to action at distinct steps; reduction of CLK1 increased HIV-1 promoter activity while depletion of CLK2 affected steps after transcript initiation. Reduced CLK1 expression also enhanced the response to several latency reversing agents, in part, by increasing the frequency of responding cells, consistent with a role in regulating provirus latency. To determine whether small molecule modulation of SR kinase function could be used to control HIV-1 replication, we screened a GSK library of protein kinase inhibitors (PKIS) and identified several pyrazolo[1,5-b] pyridazine derivatives that suppress HIV-1 gene expression/replication with an EC50 ~ 50 nM. The compounds suppressed HIV-1 protein and viral RNA accumulation with minimal impact on cell viability, inhibiting CLK1 and CLK2 but not CLK3 function, thereby selectively altering the abundance of individual CLK and SR proteins in cells. CONCLUSIONS These findings demonstrate the unique roles played by individual SR kinases in regulating HIV-1 gene expression, validating the targeting of these functions to either enhance latency reversal, essential for "Kick-and-Kill" strategies, or to silence HIV protein expression for "Block-and-Lock" strategies.
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Affiliation(s)
- Subha Dahal
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Kiera Clayton
- grid.168645.80000 0001 0742 0364Department of Pathology, University of Massachusetts Medical School, Worcester, MA 01605 USA
| | - Terek Been
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Raphaële Fernet-Brochu
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Alonso Villasmil Ocando
- grid.461656.60000 0004 0489 3491Ragon Institute of MGH, MIT and Harvard, Cambridge, MA 02139 USA
| | - Ahalya Balachandran
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Mikaël Poirier
- grid.86715.3d0000 0000 9064 6198Dept. of Microbiology & Infectious Diseases, Université de Sherbrooke, Sherbrooke, QC Canada
| | - Rebecca Kaddis Maldonado
- grid.240473.60000 0004 0543 9901Department of Medicine, Penn State College of Medicine, Hershey, PA 17033 USA ,grid.240473.60000 0004 0543 9901Microbiology & Immunology, Penn State College of Medicine, Hershey, PA 17033 USA
| | - Lulzim Shkreta
- grid.86715.3d0000 0000 9064 6198Dept. of Microbiology & Infectious Diseases, Université de Sherbrooke, Sherbrooke, QC Canada
| | - Kayluz Frias Boligan
- grid.423370.10000 0001 0285 1288Center for Innovation, Canadian Blood Services, Toronto, ON Canada
| | - Furkan Guvenc
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Fariha Rahman
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Donald Branch
- grid.423370.10000 0001 0285 1288Center for Innovation, Canadian Blood Services, Toronto, ON Canada
| | - Brendan Bell
- grid.86715.3d0000 0000 9064 6198Dept. of Microbiology & Infectious Diseases, Université de Sherbrooke, Sherbrooke, QC Canada
| | - Benoit Chabot
- grid.86715.3d0000 0000 9064 6198Dept. of Microbiology & Infectious Diseases, Université de Sherbrooke, Sherbrooke, QC Canada
| | - Scott D. Gray-Owen
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
| | - Leslie J. Parent
- grid.240473.60000 0004 0543 9901Department of Medicine, Penn State College of Medicine, Hershey, PA 17033 USA ,grid.240473.60000 0004 0543 9901Microbiology & Immunology, Penn State College of Medicine, Hershey, PA 17033 USA
| | - Alan Cochrane
- grid.17063.330000 0001 2157 2938Dept. of Molecular Genetics, University of Toronto, 1 King’s College Circle, Toronto, ON M5S1A8 Canada
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9
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Localization and functions of native and eGFP-tagged capsid proteins in HIV-1 particles. PLoS Pathog 2022; 18:e1010754. [PMID: 35951676 PMCID: PMC9426931 DOI: 10.1371/journal.ppat.1010754] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 08/30/2022] [Accepted: 07/21/2022] [Indexed: 12/24/2022] Open
Abstract
In infectious HIV-1 particles, the capsid protein (CA) forms a cone-shaped shell called the capsid, which encases the viral ribonucleoprotein complex (vRNP). Following cellular entry, the capsid is disassembled through a poorly understood process referred to as uncoating, which is required to release the reverse transcribed HIV-1 genome for integration into host chromatin. Whereas single virus imaging using indirect CA labeling techniques suggested uncoating to occur in the cytoplasm or at the nuclear pore, a recent study using eGFP-tagged CA reported uncoating in the nucleus. To delineate the HIV-1 uncoating site, we investigated the mechanism of eGFP-tagged CA incorporation into capsids and the utility of this fluorescent marker for visualizing HIV-1 uncoating. We find that virion incorporated eGFP-tagged CA is effectively excluded from the capsid shell, and that a subset of the tagged CA is vRNP associated. These results thus imply that eGFP-tagged CA is not a direct marker for capsid uncoating. We further show that native CA co-immunoprecipitates with vRNP components, providing a basis for retention of eGFP-tagged and untagged CA by sub-viral complexes in the nucleus. Moreover, we find that functional viral replication complexes become accessible to integrase-interacting host factors at the nuclear pore, leading to inhibition of infection and demonstrating capsid permeabilization prior to nuclear import. Finally, we find that HIV-1 cores containing a mixture of wild-type and mutant CA interact differently with cytoplasmic versus nuclear pools of the CA-binding host cofactor CPSF6. Our results suggest that capsid remodeling (including a loss of capsid integrity) is the predominant pathway for HIV-1 nuclear entry and provide new insights into the mechanism of CA retention in the nucleus via interaction with vRNP components. The timing, location and mechanisms of HIV-1 capsid disassembly which is referred to as uncoating remains unclear. Direct labeling of HIV-1 capsids, by incorporating a few green fluorescent proteins (GFP) tagged capsid protein (CA) into virions allows to image the spatio-temporal loss of HIV-1 CA during virus infection. However, the localization and functions of a few virion incorporated eGFP-tagged CA proteins remain unclear, since <50% of virus packaged CA proteins participate to form the conical capsid shell that protects the HIV-1 genome. Here we developed several approaches to test the localization and function of eGFP-tagged CA proteins in virions. We found that eGFP-tagged CA proteins are excluded from the conical capsid shell and that a subset of these proteins is associated with the viral ribonucleoprotein complex (vRNPs), through direct interactions between CA and vRNP components. eGFP-tagged CA is retained in the nucleus by virtue of vRNP association and is unlikely to report on HIV-1 capsid disassembly. We also found that HIV-1 capsids become permeabilized and are remodeled during their transport into the nucleus. Our study provides new insights into the ability of CA to interact with vRNPs for its retention in the nucleus and highlights capsid remodeling as a preferred pathway for HIV-1 entry into the nucleus.
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10
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Saulnier O, Guedri-Idjouadiene K, Aynaud MM, Chakraborty A, Bruyr J, Pineau J, O'Grady T, Mirabeau O, Grossetête S, Galvan B, Claes M, Al Oula Hassoun Z, Sadacca B, Laud K, Zaïdi S, Surdez D, Baulande S, Rambout X, Tirode F, Dutertre M, Delattre O, Dequiedt F. ERG transcription factors have a splicing regulatory function involving RBFOX2 that is altered in the EWS-FLI1 oncogenic fusion. Nucleic Acids Res 2021; 49:5038-5056. [PMID: 34009296 PMCID: PMC8136815 DOI: 10.1093/nar/gkab305] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 04/12/2021] [Accepted: 04/14/2021] [Indexed: 01/30/2023] Open
Abstract
ERG family proteins (ERG, FLI1 and FEV) are a subfamily of ETS transcription factors with key roles in physiology and development. In Ewing sarcoma, the oncogenic fusion protein EWS-FLI1 regulates both transcription and alternative splicing of pre-messenger RNAs. However, whether wild-type ERG family proteins might regulate splicing is unknown. Here, we show that wild-type ERG proteins associate with spliceosomal components, are found on nascent RNAs, and induce alternative splicing when recruited onto a reporter minigene. Transcriptomic analysis revealed that ERG and FLI1 regulate large numbers of alternative spliced exons (ASEs) enriched with RBFOX2 motifs and co-regulated by this splicing factor. ERG and FLI1 are associated with RBFOX2 via their conserved carboxy-terminal domain, which is present in EWS-FLI1. Accordingly, EWS-FLI1 is also associated with RBFOX2 and regulates ASEs enriched in RBFOX2 motifs. However, in contrast to wild-type ERG and FLI1, EWS-FLI1 often antagonizes RBFOX2 effects on exon inclusion. In particular, EWS-FLI1 reduces RBFOX2 binding to the ADD3 pre-mRNA, thus increasing its long isoform, which represses the mesenchymal phenotype of Ewing sarcoma cells. Our findings reveal a RBFOX2-mediated splicing regulatory function of wild-type ERG family proteins, that is altered in EWS-FLI1 and contributes to the Ewing sarcoma cell phenotype.
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Affiliation(s)
- Olivier Saulnier
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, F-75013 Paris, France
| | - Katia Guedri-Idjouadiene
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Marie-Ming Aynaud
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Alina Chakraborty
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Université Paris-Saclay, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Équipe Labellisée Ligue Nationale Contre le Cancer, F-91405 Orsay, France
| | - Jonathan Bruyr
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Joséphine Pineau
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Tina O'Grady
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Olivier Mirabeau
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sandrine Grossetête
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Bartimée Galvan
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Margaux Claes
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Zahra Al Oula Hassoun
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Benjamin Sadacca
- INSERM U932, RT2Lab Team, Translational Research Department, PSL Research University, Institut Curie, F-75005 Paris, France.,CNRS UMR5219, Institut de Mathématiques de Toulouse; Université de Toulouse; F-31062 Toulouse, France
| | - Karine Laud
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sakina Zaïdi
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Didier Surdez
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Sylvain Baulande
- Institut Curie, PSL Research University, NGS Platform, 26 rue d'Ulm, F-75005 Paris, France
| | - Xavier Rambout
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
| | - Franck Tirode
- Claude Bernard University Lyon 1, INSERM 1052, CNRS 5286, Cancer Research Center of Lyon (CRCL), Lyon University, Lyon, France
| | - Martin Dutertre
- Institut Curie, PSL Research University, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Université Paris-Saclay, CNRS UMR3348, INSERM U1278, F-91405 Orsay, France.,Équipe Labellisée Ligue Nationale Contre le Cancer, F-91405 Orsay, France
| | - Olivier Delattre
- INSERM U830, Équipe Labellisée LNCC, PSL Research University, SIREDO Oncology Centre, Institut Curie, 75005 Paris, France
| | - Franck Dequiedt
- University of Liège, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), Liège, Belgium.,University of Liège, GIGA-Molecular Biology of Diseases, Liège, Belgium
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11
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Wang H, Jiang Y. SRp20: A potential therapeutic target for human tumors. Pathol Res Pract 2021; 224:153444. [PMID: 34126370 DOI: 10.1016/j.prp.2021.153444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/11/2021] [Accepted: 04/11/2021] [Indexed: 12/12/2022]
Abstract
As an important member of SR protein family, SRp20 plays a crucial role in alternative splicing. It not only participates in cell cycle regulation, export of mRNA, cleaving of primary microRNAs, homologous recombination-mediated DNA repair, cellular senescence and apoptosis, but also gets involved in the integrity and pluripotency of genome. Alternative splicing maintains a strict balance in the body to ensure the normal physiological function of cells. Once the balance is broken, diseases, even tumors, will follow. Through the analysis of SRp20-related articles, we found that Alzheimer's disease, glaucoma, bipolar disorder and other diseases have a certain relationship with SRp20. More importantly, SRp20 is closely related to the occurrence, proliferation, invasion and metastasis of various tumors, as well as chemotherapy resistance. Some SRp20 inhibitors have shown significant anticancer efficacy, suggesting a potential therapeutic strategy for tumors.
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Affiliation(s)
- Han Wang
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital & Shenzhen Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Shenzhen, China
| | - Yanxia Jiang
- Department of Pathology, The Affiliated Hospital of Qingdao University, Qingdao, China.
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12
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Hwang JY, Jung S, Kook TL, Rouchka EC, Bok J, Park JW. rMAPS2: an update of the RNA map analysis and plotting server for alternative splicing regulation. Nucleic Acids Res 2020; 48:W300-W306. [PMID: 32286627 PMCID: PMC7319468 DOI: 10.1093/nar/gkaa237] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 03/26/2020] [Accepted: 04/01/2020] [Indexed: 11/17/2022] Open
Abstract
The rMAPS2 (RNA Map Analysis and Plotting Server 2) web server, freely available at http://rmaps.cecsresearch.org/, has provided the high-throughput sequencing data research community with curated tools for the identification of RNA binding protein sites. rMAPS2 analyzes differential alternative splicing or CLIP peak data obtained from high-throughput sequencing data analysis tools like MISO, rMATS, Piranha, PIPE-CLIP and PARalyzer, and then, graphically displays enriched RNA-binding protein target sites. The initial release of rMAPS focused only on the most common alternative splicing event, skipped exon or exon skipping. However, there was a high demand for the analysis of other major types of alternative splicing events, especially for retained intron events since this is the most common type of alternative splicing in plants, such as Arabidopsis thaliana. Here, we expanded the implementation of rMAPS2 to facilitate analyses for all five major types of alternative splicing events: skipped exon, mutually exclusive exons, alternative 5′ splice site, alternative 3′ splice site and retained intron. In addition, by employing multi-threading, rMAPS2 has vastly improved the user experience with significant reductions in running time, ∼3.5 min for the analysis of all five major alternative splicing types at once.
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Affiliation(s)
- Jae Y Hwang
- Department of Computer Science and Engineering, University of Louisville, Louisville, KY 40292, USA
| | - Sungbo Jung
- Department of Computer Science and Engineering, University of Louisville, Louisville, KY 40292, USA
| | - Tae L Kook
- Department of Computer Science and Engineering, University of Louisville, Louisville, KY 40292, USA
| | - Eric C Rouchka
- Department of Computer Science and Engineering, University of Louisville, Louisville, KY 40292, USA.,KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.,Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul 03722, Republic of Korea.,BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul 03722, Republic of Korea
| | - Juw W Park
- Department of Computer Science and Engineering, University of Louisville, Louisville, KY 40292, USA.,KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40292, USA
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13
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Wineberg Y, Bar-Lev TH, Futorian A, Ben-Haim N, Armon L, Ickowicz D, Oriel S, Bucris E, Yehuda Y, Pode-Shakked N, Gilad S, Benjamin S, Hohenstein P, Dekel B, Urbach A, Kalisky T. Single-Cell RNA Sequencing Reveals mRNA Splice Isoform Switching during Kidney Development. J Am Soc Nephrol 2020; 31:2278-2291. [PMID: 32651222 DOI: 10.1681/asn.2019080770] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 05/23/2020] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND During mammalian kidney development, nephron progenitors undergo a mesenchymal-to-epithelial transition and eventually differentiate into the various tubular segments of the nephron. Recently, Drop-seq single-cell RNA sequencing technology for measuring gene expression from thousands of individual cells identified the different cell types in the developing kidney. However, that analysis did not include the additional layer of heterogeneity that alternative mRNA splicing creates. METHODS Full transcript length single-cell RNA sequencing characterized the transcriptomes of 544 individual cells from mouse embryonic kidneys. RESULTS Gene expression levels measured with full transcript length single-cell RNA sequencing identified each cell type. Further analysis comprehensively characterized splice isoform switching during the transition between mesenchymal and epithelial cellular states, which is a key transitional process in kidney development. The study also identified several putative splicing regulators, including the genes Esrp1/2 and Rbfox1/2. CONCLUSIONS Discovery of the sets of genes that are alternatively spliced as the fetal kidney mesenchyme differentiates into tubular epithelium will improve our understanding of the molecular mechanisms that drive kidney development.
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Affiliation(s)
- Yishay Wineberg
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Tali Hana Bar-Lev
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Anna Futorian
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Nissim Ben-Haim
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Leah Armon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Debby Ickowicz
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Sarit Oriel
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Efrat Bucris
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Yishai Yehuda
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
| | - Naomi Pode-Shakked
- Pediatric Stem Cell Research Institute, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel.,Division of Pediatric Nephrology, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Shlomit Gilad
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Sima Benjamin
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot, Israel
| | - Peter Hohenstein
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Benjamin Dekel
- Pediatric Stem Cell Research Institute, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel-Hashomer, Israel.,Division of Pediatric Nephrology, Sheba Medical Center, Tel-Hashomer, Israel.,Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Achia Urbach
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Tomer Kalisky
- Department of Bioengineering and Bar-Ilan Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat Gan, Israel
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14
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More DA, Kumar A. SRSF3: Newly discovered functions and roles in human health and diseases. Eur J Cell Biol 2020; 99:151099. [PMID: 32800280 DOI: 10.1016/j.ejcb.2020.151099] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/15/2020] [Accepted: 06/29/2020] [Indexed: 12/21/2022] Open
Abstract
The serine/arginine rich proteins (SR proteins) are members of a family of RNA binding proteins involved in regulating various features of RNA metabolism, including pre-mRNA constitutive and alternative splicing. In humans, a total of 12 SR splicing factors (SRSFs) namely SRSF1-SRSF12 have been reported. SRSF3, the smallest member of the SR family and the focus of this review, regulates critical steps in mRNA metabolism and has been shown to have mRNA-independent functions as well. Recent studies on SRSF3 have uncovered its role in a wide array of complex biological processes. We have also reviewed the involvement of SRSF3 in disease conditions like cancer, ageing, neurological and cardiac disorders. Finally, we have discussed in detail the autoregulation of SRSF3 and its implications in cancer and commented on the potential of SRSF3 as a therapeutic target, especially in the context of cancer.
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Affiliation(s)
- Dhanashree Anil More
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Arun Kumar
- Department of Molecular Reproduction, Development and Genetics, Indian Institute of Science, Bangalore, 560012, India.
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15
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Jin X, Wang J, Zou S, Xu R, Cao J, Zhang Y, Guo J, Wen X, Deng S, Zheng Y, Zhu Y, Wang F, Xu Z. Cinobufagin Triggers Defects in Spindle Formation and Cap-Dependent Translation in Liver Cancer Cells by Inhibiting the AURKA-mTOR-eIF4E Axis. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2020; 48:651-678. [PMID: 32349518 DOI: 10.1142/s0192415x20500330] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cinobufagin is a Na+/K+-ATPase (NKA) inhibitor with excellent anticancer effects to prolong the survival of patients. The purpose of the present study was to clarify the underlying mechanism of the anticancer effects of cinobufagin using overexpression or inhibition of aurora kinase A (AURKA) signaling. First, high expression of Na+/K+-ATPase alpha 1 subunit (ATP1A1) and AURAK resulted in increased malignant transformation in hepatocellular carcinoma (HCC) patients using the cancer genome atlas (TCGA) data and tissue samples. After treatment with cinobufagin, we successfully screened 202, 249, and 335 changing expression proteins in Huh-7 cells under normal, overexpression, and inhibition of AURKA using tandem mass tags (TMT)-labeled quantitative proteomics coupled to 2D liquid chromatography-tandem mass spectrometry (LC-MS/MS). Bioinformatics analysis revealed that these molecules were closely associated with chromosome segregation, DNA damage, and regulation of translation processes. We further confirmed that cinobufagin induced DNA damage and chromosome segregation disorders and suppresses translational processing in oncogenes by decreasing the expression of AURKA, mechanistic target of rapamycin kinase (mTOR), p-mTOR, p-extracellular regulated protein kinases (ERK), eukaryotic translation initiation factor 4E (eIF4E), and p-eIF4E, while increasing the expression of p-eukaryotic translation initiation factor 4E binding protein 1 (4E-BP1) (S65, T37, T46, T45) and increasing the interaction between eIF4 and 4E-BP1. Our results suggested that cinobufagin performed an antitumor effects in liver cancer cells by inhibiting the AURKA-mTOR-eIF4E axis.
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Affiliation(s)
- Xiaohan Jin
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Jiabao Wang
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Shuang Zou
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Ruicheng Xu
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Jin Cao
- Department of Gastroenterology and Hepatology, Third Central Hospital of Tianjin, Tianjin City 300170, P. R. China
| | - Yan Zhang
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Jia Guo
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Xiaochang Wen
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Sanmin Deng
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
| | - Yupiao Zheng
- Department of Gastroenterology and Hepatology, Third Central Hospital of Tianjin, Tianjin City 300170, P. R. China
| | - Yu Zhu
- Department of Clinical Laboratory, Tianjin Key Laboratory of Cerebral Vessels and Neurodegenerative Diseases, Tianjin Huanhu Hospital, Tianjin City 300350, P. R. China
| | - Fengmei Wang
- Department of Gastroenterology and Hepatology, Third Central Hospital of Tianjin, Tianjin City 300170, P. R. China
| | - Zhongwei Xu
- Central Laboratory, Logistics University of Chinese People’s Armed Police Force, Tianjin City 300309, P. R. China
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16
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An S, Huang W, Huang X, Cun Y, Cheng W, Sun X, Ren Z, Chen Y, Chen W, Wang J. Integrative network analysis identifies cell-specific trans regulators of m6A. Nucleic Acids Res 2020; 48:1715-1729. [PMID: 31912146 PMCID: PMC7038928 DOI: 10.1093/nar/gkz1206] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Revised: 12/03/2019] [Accepted: 12/18/2019] [Indexed: 12/21/2022] Open
Abstract
N6-methyladenosine (m6A) is a reversible and dynamic RNA modification in eukaryotes. However, how cells establish cell-specific m6A methylomes is still poorly understood. Here, we developed a computational framework to systematically identify cell-specific trans regulators of m6A through integrating gene expressions, binding targets and binding motifs of large number of RNA binding proteins (RBPs) with a co-methylation network constructed using large-scale m6A methylomes across diverse cell states. We applied the framework and successfully identified 32 high-confidence m6A regulators that modulated the variable m6A sites away from stop codons in a cell-specific manner. To validate them, we knocked down three regulators respectively and found two of them (TRA2A and CAPRIN1) selectively promoted the methylations of the m6A sites co-localized with their binding targets on RNAs through physical interactions with the m6A writers. Knockdown of TRA2A increased the stabilities of the RNAs with TRA2A bound near the m6A sites and decreased the viability of cells. The successful identification of m6A regulators demonstrates a powerful and widely applicable strategy to elucidate the cell-specific m6A regulators. Additionally, our discovery of pervasive trans-acting regulating of m6A provides novel insights into the mechanisms by which spatial and temporal dynamics of m6A methylomes are established.
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Affiliation(s)
- Sanqi An
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Wanxu Huang
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiang Huang
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Yixian Cun
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Weisheng Cheng
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Xiang Sun
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Zhijun Ren
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Yaxin Chen
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Wenfang Chen
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China
| | - Jinkai Wang
- Department of Medical Bioinformatics, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.,Center for Stem Cell Biology and Tissue Engineering, Key Laboratory for Stem Cells and Tissue Engineering, Ministry of Education, Sun Yat-sen University, Guangzhou 510080, China.,RNA Biomedical Institute, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510120, China.,Center for Precision Medicine, Sun Yat-sen University, Guangzhou 510080, China
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17
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Wong RW, Balachandran A, Cheung PK, Cheng R, Pan Q, Stoilov P, Harrigan PR, Blencowe BJ, Branch DR, Cochrane A. An activator of G protein-coupled receptor and MEK1/2-ERK1/2 signaling inhibits HIV-1 replication by altering viral RNA processing. PLoS Pathog 2020; 16:e1008307. [PMID: 32069328 PMCID: PMC7048317 DOI: 10.1371/journal.ppat.1008307] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 02/28/2020] [Accepted: 01/06/2020] [Indexed: 12/17/2022] Open
Abstract
The ability of HIV-1 to evolve resistance to combined antiretroviral therapies (cARTs) has stimulated research into alternative means of controlling this infection. We assayed >60 modulators of RNA alternative splicing (AS) to identify new inhibitors of HIV-1 RNA processing-a segment of the viral lifecycle not targeted by current drugs-and discovered compound N-[4-chloro-3-(trifluoromethyl)phenyl]-7-nitro-2,1,3-benzoxadiazol-4-amine (5342191) as a potent inhibitor of both wild-type (Ba-L, NL4-3, LAI, IIIB, and N54) and drug-resistant strains of HIV-1 (IC50: ~700 nM) with no significant effect on cell viability at doses tested. 5342191 blocks expression of four essential HIV-1 structural and regulatory proteins (Gag, Env, Tat, and Rev) without affecting total protein synthesis of the cell. This response is associated with altered unspliced (US) and singly-spliced (SS) HIV-1 RNA accumulation (~60% reduction) and transport to the cytoplasm (loss of Rev) whereas parallel analysis of cellular RNAs revealed less than a 0.7% of host alternative splicing (AS) events (0.25-0.67% by ≥ 10-20%), gene expression (0.01-0.46% by ≥ 2-5 fold), and protein abundance (0.02-0.34% by ≥ 1.5-2 fold) being affected. Decreased expression of Tat, but not Gag/Env, upon 5342191 treatment was reversed by a proteasome inhibitor, suggesting that this compound alters the synthesis/degradation of this key viral factor. Consistent with an affect on HIV-1 RNA processing, 5342191 treatment of cells altered the abundance and phosphorylation of serine/arginine-rich splicing factor (SRSF) 1, 3, and 4. Despite the activation of several intracellular signaling pathways by 5342191 (Ras, MEK1/2-ERK1/2, and JNK1/2/3), inhibition of HIV-1 gene expression by this compound could be reversed by pre-treatment with either a G-protein α-subunit inhibitor or two different MEK1/2 inhibitors. These observations demonstrate enhanced sensitivity of HIV-1 gene expression to small changes in host RNA processing and highlights the potential of modulating host intracellular signaling as an alternative approach for controlling HIV-1 infection.
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Affiliation(s)
- Raymond W. Wong
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | - Ahalya Balachandran
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Peter K. Cheung
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
| | - Ran Cheng
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Qun Pan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Peter Stoilov
- Department of Biochemistry, West Virginia University, Morgantown, West Virginia, United States of America
| | - P. Richard Harrigan
- British Columbia Centre for Excellence in HIV/AIDS, Vancouver, British Columbia, Canada
- Department of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Benjamin J. Blencowe
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Donald R. Branch
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
- Division of Advanced Diagnostics, Infection and Immunity Group, Toronto General Hospital Research Institute, Toronto, Ontario, Canada
- Centre for Innovation, Canadian Blood Services, Toronto, Ontario, Canada
| | - Alan Cochrane
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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18
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Sun Y, Yan L, Guo J, Shao J, Jia R. Downregulation of SRSF3 by antisense oligonucleotides sensitizes oral squamous cell carcinoma and breast cancer cells to paclitaxel treatment. Cancer Chemother Pharmacol 2019; 84:1133-1143. [PMID: 31515668 DOI: 10.1007/s00280-019-03945-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Accepted: 08/28/2019] [Indexed: 12/30/2022]
Abstract
PURPOSE Paclitaxel (PTX) is widely used in the chemotherapy of many cancers, including breast cancer and oral squamous cell carcinoma (OSCC). However, many patients respond poorly to PTX treatment. The SRSF3 oncogene and several splicing factors play important roles in OSCC tumorigenesis. This study aimed to understand the function of splicing factors in PTX treatment and improve the therapeutic effects of PTX treatment. METHODS Splicing factors regulated by PTX treatment were screened in CAL 27 cell by reverse transcription polymerase chain reaction. The function of SRSF3 in PTX treatment was analyzed by gain-of-function or loss-of-function assay in OSCC cell lines CAL 27 and SCC-9 and breast cancer cell line MCF-7. Alternative splicing of SRSF3 exon 4 in cancer tissues or cells was analyzed by RT-PCR and online program TSVdb. SRSF3-specific antisense oligonucleotide (ASO) SR-3 was used to downregulate SRSF3 expression and enhance the effect of PTX treatment. RESULTS PTX treatment decreased SRSF3 expression, and SRSF3 overexpression rescued the growth inhibition caused by PTX in both OSCC and breast cancer cells. Moreover, we found that PTX treatment could repress SRSF3 exon 4 (containing an in-frame stop codon) exclusion and then decrease the SRSF3 protein expression. Increased exclusion of SRSF3 exon 4 is correlated with poor survival in OSCC and breast cancer patients. SR-3 downregulated SRSF3 protein expression and significantly increased the sensitivity of cancer cells to PTX treatment. CONCLUSIONS SRSF3 downregulation by ASO sensitizes cancer cells to PTX treatment.
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Affiliation(s)
- Yanan Sun
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, 430079, Wuhan, People's Republic of China
| | - Lingyan Yan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, 430079, Wuhan, People's Republic of China
| | - Jihua Guo
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, 430079, Wuhan, People's Republic of China.
| | - Jun Shao
- Hubei Cancer Hospital, 116 Zhuodaoquan South Load, 430079, Wuhan, People's Republic of China.
| | - Rong Jia
- The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) and Key Laboratory of Oral Biomedicine Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, 430079, Wuhan, People's Republic of China.
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19
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Maury Y, Poydenot P, Brinon B, Lesueur L, Gide J, Roquevière S, Côme J, Polvèche H, Auboeuf D, Alexandre Denis J, Pietu G, Furling D, Lechuga M, Baghdoyan S, Peschanski M, Martinat C. Pluripotent Stem Cell-Based Drug Screening Reveals Cardiac Glycosides as Modulators of Myotonic Dystrophy Type 1. iScience 2019; 11:258-271. [PMID: 30639849 PMCID: PMC6327858 DOI: 10.1016/j.isci.2018.12.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 12/14/2018] [Accepted: 12/20/2018] [Indexed: 02/06/2023] Open
Abstract
There is currently no treatment for myotonic dystrophy type 1 (DM1), the most frequent myopathy of genetic origin. This progressive neuromuscular disease is caused by nuclear-retained RNAs containing expanded CUG repeats. These toxic RNAs alter the activities of RNA splicing factors, resulting in alternative splicing misregulation. By combining human mutated pluripotent stem cells and phenotypic drug screening, we revealed that cardiac glycosides act as modulators for both upstream nuclear aggregations of DMPK mRNAs and several downstream alternative mRNA splicing defects. However, these occurred at different drug concentration ranges. Similar biological effects were recorded in a DM1 mouse model. At the mechanistic level, we demonstrated that this effect was calcium dependent and was synergic with inhibition of the ERK pathway. These results further underscore the value of stem-cell-based assays for drug discovery in monogenic diseases. Myotonic dystrophy type 1 hPSCs were adapted for high content screening FDA-approved cardiac glycosides normalize in vitro and in vivo DM1 biological markers Cardiac glycosides synergize with the ERK pathway to normalize DM1 biomarkers This study emphasizes the value of human pluripotent stem cells for drug discovery
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Affiliation(s)
- Yves Maury
- CECS, I-STEM, AFM, 91100 Corbeil-Essonnes, France
| | | | | | - Lea Lesueur
- INSERM, UMR 861, UEVE, ISTEM, AFM, 91100 Corbeil-Essonnes, France
| | | | | | - Julien Côme
- CECS, I-STEM, AFM, 91100 Corbeil-Essonnes, France
| | | | | | | | - Geneviève Pietu
- INSERM, UMR 861, UEVE, ISTEM, AFM, 91100 Corbeil-Essonnes, France
| | - Denis Furling
- Sorbonne Universités UPMC Univ Paris 06, INSERM, Centre de Recherche en Myologie - UMRS974, Institut de Myologie, 75013 Paris, France
| | - Marc Lechuga
- CECS, I-STEM, AFM, 91100 Corbeil-Essonnes, France
| | | | - Marc Peschanski
- CECS, I-STEM, AFM, 91100 Corbeil-Essonnes, France; INSERM, UMR 861, UEVE, ISTEM, AFM, 91100 Corbeil-Essonnes, France
| | - Cécile Martinat
- INSERM, UMR 861, UEVE, ISTEM, AFM, 91100 Corbeil-Essonnes, France.
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20
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Liss M, Radke MH, Eckhard J, Neuenschwander M, Dauksaite V, von Kries JP, Gotthardt M. Drug discovery with an RBM20 dependent titin splice reporter identifies cardenolides as lead structures to improve cardiac filling. PLoS One 2018; 13:e0198492. [PMID: 29889873 PMCID: PMC5995442 DOI: 10.1371/journal.pone.0198492] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Accepted: 05/20/2018] [Indexed: 02/07/2023] Open
Abstract
Diastolic dysfunction is increasingly prevalent in our ageing society and an important contributor to heart failure. The giant protein titin could serve as a therapeutic target, as its elastic properties are a main determinant of cardiac filling in diastole. This study aimed to develop a high throughput pharmacological screen to identify small molecules that affect titin isoform expression through differential inclusion of exons encoding the elastic PEVK domains. We used a dual luciferase splice reporter assay that builds on the titin splice factor RBM20 to screen ~34,000 small molecules and identified several compounds that inhibit the exclusion of PEVK exons. These compounds belong to the class of cardenolides and affect RBM20 dependent titin exon exclusion but did not affect RBFOX1 mediated splicing of FMNL3. We provide evidence that cardenolides do not bind to the RNA interacting domain of RBM20, but reduce RBM20 protein levels and alter transcription of select splicing factors that interact with RBM20. Cardenolides affect titin isoform expression. Understanding their mode of action and harnessing the splice effects through chemical modifications that suppress the effects on ion homeostasis and more selectively affect cardiac splicing has the potential to improve cardiac filling and thus help patients with diastolic heart failure, for which currently no targeted therapy exists.
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Affiliation(s)
- Martin Liss
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Michael H. Radke
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany
| | - Jamina Eckhard
- Screening Unit, Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | | | - Vita Dauksaite
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | | | - Michael Gotthardt
- Neuromuscular and Cardiovascular Cell Biology, Max Delbrueck Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, Berlin, Germany
- * E-mail:
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21
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Chung MH, Wang YW, Chang YL, Huang SM, Lin WS. Risk of cancer in patients with heart failure who use digoxin: a 10-year follow-up study and cell-based verification. Oncotarget 2018; 8:44203-44216. [PMID: 28496002 PMCID: PMC5546474 DOI: 10.18632/oncotarget.17410] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 03/30/2017] [Indexed: 12/21/2022] Open
Abstract
Heart failure (HF) is the leading cause of death in the world and digoxin remains one of the oldest therapies for HF. However, its safety and efficacy have been controversial since its initial use and there is uncertainty about its long-term efficacy and safety. Recently, the repositioning of cardiac glycosides is to function in anti-tumor activity via multiple working pathways. It is interesting to compare the potential effects of digoxin in clinical patients and cell lines. First, we analyze patient information retrieved from the National Health Insurance Research database of Taiwan between January 1, 2000 and December 31, 2000. This retrospective study included a study cohort (1,219 patients) and a comparison cohort. Our analytical data suggested that patients taking digoxin are at an increased risk of cancers, including breast, liver, and lung cancers, during the 10-year follow-up period. In contrast to the anti-tumor function of digoxin, we further examined the potential pathway of digoxin via the cell-based strategy using several breast cancer cell lines, including MCF-7, BT-474, MAD-MB-231, and ZR-75-1. Digoxin consistently exerted its cytotoxicity to these four cell lines with various range of concentration. However, the proliferation of ZR-75-1 cells was the only cell lines induced by digoxin and the others were dramatically suppressed by digoxin. The responsiveness of SRSF3 to digoxin might be involved with cell-type differences. In summary, we combined a cohort study for digoxin treatment for HF patients with a cell-based strategy that addresses the translation issue, which revealed the complexity of personalized medicine.
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Affiliation(s)
- Min-Huey Chung
- Graduate Institute of Nursing, College of Nursing, Taipei Medical University, Taipei 110, Taiwan, Republic of China
| | - Yi-Wen Wang
- Department of Biology and Anatomy, National Defense Medical Center, Taipei City 114, Taiwan, Republic of China
| | - Yung-Lung Chang
- Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, Republic of China
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, Republic of China
| | - Wei-Shiang Lin
- Department of Medicine, Division of Cardiology, Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan, Republic of China
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22
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Wong RW, Lingwood CA, Ostrowski MA, Cabral T, Cochrane A. Cardiac glycoside/aglycones inhibit HIV-1 gene expression by a mechanism requiring MEK1/2-ERK1/2 signaling. Sci Rep 2018; 8:850. [PMID: 29339801 PMCID: PMC5770468 DOI: 10.1038/s41598-018-19298-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 11/07/2017] [Indexed: 12/14/2022] Open
Abstract
The capacity of HIV-1 to develop resistance to current drugs calls for innovative strategies to control this infection. We aimed at developing novel inhibitors of HIV-1 replication by targeting viral RNA processing—a stage dependent on conserved host processes. We previously reported that digoxin is a potent inhibitor of this stage. Herein, we identify 12 other cardiac glycoside/aglycones or cardiotonic steroids (CSs) that impede HIV growth in HIV-infected T cells from clinical patients at IC50s (1.1–1.3 nM) that are 2–26 times below concentrations used in patients with heart conditions. We subsequently demonstrate that CSs inhibit HIV-1 gene expression in part through modulation of MEK1/2-ERK1/2 signaling via interaction with the Na+/K+-ATPase, independent of alterations in intracellular Ca2+. Supporting this hypothesis, depletion of the Na+/K+-ATPase or addition of a MEK1/2-ERK1/2 activator also impairs HIV-1 gene expression. Similar to digoxin, all CSs tested induce oversplicing of HIV-1 RNAs, reducing unspliced (Gag) and singly spliced RNAs (Env/p14-Tat) encoding essential HIV-1 structural/regulatory proteins. Furthermore, all CSs cause nuclear retention of genomic/unspliced RNAs, supporting viral RNA processing as the underlying mechanism for their disruption of HIV-1 replication. These findings call for further in vivo validation and supports the targeting of cellular processes to control HIV-1 infection.
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Affiliation(s)
- Raymond W Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Clifford A Lingwood
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Division of Molecular Structure and Function, Hospital for Sick Children, Toronto, ON, M5G1X8, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, M5S1A8, Canada
| | - Mario A Ostrowski
- Keenan Research Centre for Biomedical Science of St. Michael's Hospital Toronto, Toronto, ON, M5B1W8, Canada.,Department of Medicine, University of Toronto, Toronto, Ontario, M5S1A8, Canada.,Department of Immunology, University of Toronto, Toronto, ON, M5S1A8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Tyler Cabral
- Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada
| | - Alan Cochrane
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S1A8, Canada. .,Department of Molecular Genetics, University of Toronto, Toronto, ON, M5S1A8, Canada.
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23
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Lambert CA, Garbacki N, Colige AC. Chemotherapy induces alternative transcription and splicing: Facts and hopes for cancer treatment. Int J Biochem Cell Biol 2017; 91:84-97. [DOI: 10.1016/j.biocel.2017.04.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2016] [Revised: 04/04/2017] [Accepted: 04/15/2017] [Indexed: 01/14/2023]
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24
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Alternative Splicing in Genetic Diseases: Improved Diagnosis and Novel Treatment Options. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2017; 335:85-141. [PMID: 29305015 DOI: 10.1016/bs.ircmb.2017.07.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Alternative splicing is an important mechanism to regulate gene expression and to expand the repertoire of gene products in order to accommodate an increase in complexity of multicellular organisms. It needs to be precisely regulated, which is achieved via RNA structure, splicing factors, transcriptional regulation, and chromatin. Changes in any of these factors can lead to disease. These may include the core spliceosome, splicing enhancer/repressor sequences and their interacting proteins, the speed of transcription by RNA polymerase II, and histone modifications. While the basic principle of splicing is well understood, it is still very difficult to predict splicing outcome, due to the multiple levels of regulation. Current molecular diagnostics mainly uses Sanger sequencing of exons, or next-generation sequencing of gene panels or the whole exome. Functional analysis of potential splicing variants is scarce, and intronic variants are often not considered. This likely results in underestimation of the percentage of splicing variants. Understanding how sequence variants may affect splicing is not only crucial for confirmation of diagnosis and for genetic counseling, but also for the development of novel treatment options. These include small molecules, transsplicing, antisense oligonucleotides, and gene therapy. Here we review the current state of molecular mechanisms of splicing regulation and how deregulation can lead to human disease, diagnostics to detect splicing variants, and novel treatment options based on splicing correction.
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25
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Screening for small molecule inhibitors of HIV-1 Gag expression. Methods 2017; 126:201-208. [DOI: 10.1016/j.ymeth.2017.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/08/2017] [Accepted: 06/05/2017] [Indexed: 01/03/2023] Open
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26
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Suppression of Adenovirus Replication by Cardiotonic Steroids. J Virol 2017; 91:JVI.01623-16. [PMID: 27881644 DOI: 10.1128/jvi.01623-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 11/15/2016] [Indexed: 12/12/2022] Open
Abstract
The dependence of adenovirus on the host pre-RNA splicing machinery for expression of its complete genome potentially makes it vulnerable to modulators of RNA splicing, such as digoxin and digitoxin. Both drugs reduced the yields of four human adenoviruses (HAdV-A31, -B35, and -C5 and a species D conjunctivitis isolate) by at least 2 to 3 logs by affecting one or more steps needed for genome replication. Immediate early E1A protein levels are unaffected by the drugs, but synthesis of the delayed protein E4orf6 and the major late capsid protein hexon is compromised. Quantitative reverse transcription-PCR (qRT-PCR) analyses revealed that both drugs altered E1A RNA splicing (favoring the production of 13S over 12S RNA) early in infection and partially blocked the transition from 12S and 13S to 9S RNA at late stages of virus replication. Expression of multiple late viral protein mRNAs was lost in the presence of either drug, consistent with the observed block in viral DNA replication. The antiviral effect was dependent on the continued presence of the drug and was rapidly reversible. RIDK34, a derivative of convallotoxin, although having more potent antiviral activity, did not show an improved selectivity index. All three drugs reduced metabolic activity to some degree without evidence of cell death. By blocking adenovirus replication at one or more steps beyond the onset of E1A expression and prior to genome replication, digoxin and digitoxin show potential as antiviral agents for treatment of serious adenovirus infections. Furthermore, understanding the mechanism(s) by which digoxin and digitoxin inhibit adenovirus replication will guide the development of novel antiviral therapies. IMPORTANCE Despite human adenoviruses being a common and, in some instances, life-threating pathogen in humans, there are few well-tolerated therapies. In this report, we demonstrate that two cardiotonic steroids already in use in humans, digoxin and digitoxin, are potent inhibitors of multiple adenovirus species. A synthetic derivative of the cardiotonic steroid convallotoxin was even more potent than digoxin and digitoxin when tested with HAdV-C5. These drugs alter the cascade of adenovirus gene expression, acting after initiation of early gene expression to block viral DNA replication and synthesis of viral structural proteins. These findings validate a novel approach to treating adenovirus infections through the modulation of host cell processes.
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27
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m(6)A-LAIC-seq reveals the census and complexity of the m(6)A epitranscriptome. Nat Methods 2016; 13:692-8. [PMID: 27376769 DOI: 10.1038/nmeth.3898] [Citation(s) in RCA: 267] [Impact Index Per Article: 33.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 05/05/2016] [Indexed: 12/11/2022]
Abstract
N(6)-Methyladenosine (m(6)A) is a widespread, reversible chemical modification of RNA molecules, implicated in many aspects of RNA metabolism. Little quantitative information exists as to either how many transcript copies of particular genes are m(6)A modified ('m(6)A levels') or the relationship of m(6)A modification(s) to alternative RNA isoforms. To deconvolute the m(6)A epitranscriptome, we developed m(6)A-level and isoform-characterization sequencing (m(6)A-LAIC-seq). We found that cells exhibit a broad range of nonstoichiometric m(6)A levels with cell-type specificity. At the level of isoform characterization, we discovered widespread differences in the use of tandem alternative polyadenylation (APA) sites by methylated and nonmethylated transcript isoforms of individual genes. Strikingly, there is a strong bias for methylated transcripts to be coupled with proximal APA sites, resulting in shortened 3' untranslated regions, while nonmethylated transcript isoforms tend to use distal APA sites. m(6)A-LAIC-seq yields a new perspective on transcriptome complexity and links APA usage to m(6)A modifications.
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28
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Determination of a Comprehensive Alternative Splicing Regulatory Network and Combinatorial Regulation by Key Factors during the Epithelial-to-Mesenchymal Transition. Mol Cell Biol 2016; 36:1704-19. [PMID: 27044866 DOI: 10.1128/mcb.00019-16] [Citation(s) in RCA: 97] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 03/28/2016] [Indexed: 12/31/2022] Open
Abstract
The epithelial-to-mesenchymal transition (EMT) is an essential biological process during embryonic development that is also implicated in cancer metastasis. While the transcriptional regulation of EMT has been well studied, the role of alternative splicing (AS) regulation in EMT remains relatively uncharacterized. We previously showed that the epithelial cell-type-specific proteins epithelial splicing regulatory proteins 1 (ESRP1) and ESRP2 are important for the regulation of many AS events that are altered during EMT. However, the contributions of the ESRPs and other splicing regulators to the AS regulatory network in EMT require further investigation. Here, we used a robust in vitro EMT model to comprehensively characterize splicing switches during EMT in a temporal manner. These investigations revealed that the ESRPs are the major regulators of some but not all AS events during EMT. We determined that the splicing factor RBM47 is downregulated during EMT and also regulates numerous transcripts that switch splicing during EMT. We also determined that Quaking (QKI) broadly promotes mesenchymal splicing patterns. Our study highlights the broad role of posttranscriptional regulation during the EMT and the important role of combinatorial regulation by different splicing factors to fine tune gene expression programs during these physiological and developmental transitions.
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29
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Park JW, Jung S, Rouchka EC, Tseng YT, Xing Y. rMAPS: RNA map analysis and plotting server for alternative exon regulation. Nucleic Acids Res 2016; 44:W333-8. [PMID: 27174931 PMCID: PMC4987942 DOI: 10.1093/nar/gkw410] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/03/2016] [Indexed: 12/17/2022] Open
Abstract
RNA-binding proteins (RBPs) play a critical role in the regulation of alternative splicing (AS), a prevalent mechanism for generating transcriptomic and proteomic diversity in eukaryotic cells. Studies have shown that AS can be regulated by RBPs in a binding-site-position dependent manner. Depending on where RBPs bind, splicing of an alternative exon can be enhanced or suppressed. Therefore, spatial analyses of RBP motifs and binding sites around alternative exons will help elucidate splicing regulation by RBPs. The development of high-throughput sequencing technologies has allowed transcriptome-wide analyses of AS and RBP–RNA interactions. Given a set of differentially regulated alternative exons obtained from RNA sequencing (RNA-seq) experiments, the rMAPS web server (http://rmaps.cecsresearch.org) performs motif analyses of RBPs in the vicinity of alternatively spliced exons and creates RNA maps that depict the spatial patterns of RBP motifs. Similarly, rMAPS can also perform spatial analyses of RBP–RNA binding sites identified by cross-linking immunoprecipitation sequencing (CLIP-seq) experiments. We anticipate rMAPS will be a useful tool for elucidating RBP regulation of alternative exon splicing using high-throughput sequencing data.
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Affiliation(s)
- Juw Won Park
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, USA KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40202, USA Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Sungbo Jung
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, USA
| | - Eric C Rouchka
- Department of Computer Engineering and Computer Science, University of Louisville, Louisville, KY 40292, USA KBRIN Bioinformatics Core, University of Louisville, Louisville, KY 40202, USA
| | - Yu-Ting Tseng
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095, USA
| | - Yi Xing
- Department of Microbiology, Immunology & Molecular Genetics, University of California, Los Angeles, CA 90095, USA
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30
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Small Molecule Modulators of Pre-mRNA Splicing in Cancer Therapy. Trends Mol Med 2015; 22:28-37. [PMID: 26700537 DOI: 10.1016/j.molmed.2015.11.005] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/09/2015] [Accepted: 11/13/2015] [Indexed: 12/24/2022]
Abstract
Pre-mRNA splicing is a fundamental process in mammalian gene expression and alternative RNA splicing plays a considerable role in generating protein diversity. RNA splicing events are also key to the pathology of numerous diseases, particularly cancers. Some tumors are molecularly addicted to specific RNA splicing isoforms making interference with pre-mRNA processing a viable therapeutic strategy. Several RNA splicing modulators have recently been characterized, some showing promise in preclinical studies. While the targets of most splicing modulators are constitutive RNA processing components, possibly leading to undesirable side effects, selectivity for individual splicing events has been observed. Given the high prevalence of splicing defects in cancer, small molecule modulators of RNA processing represent a potentially promising novel therapeutic strategy in cancer treatment. Here, we review their reported effects, mechanisms, and limitations.
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31
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Transformer2 proteins protect breast cancer cells from accumulating replication stress by ensuring productive splicing of checkpoint kinase 1. Front Chem Sci Eng 2015. [DOI: 10.1007/s11705-015-1540-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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32
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Laustriat D, Gide J, Barrault L, Chautard E, Benoit C, Auboeuf D, Boland A, Battail C, Artiguenave F, Deleuze JF, Bénit P, Rustin P, Franc S, Charpentier G, Furling D, Bassez G, Nissan X, Martinat C, Peschanski M, Baghdoyan S. In Vitro and In Vivo Modulation of Alternative Splicing by the Biguanide Metformin. MOLECULAR THERAPY-NUCLEIC ACIDS 2015; 4:e262. [PMID: 26528939 PMCID: PMC4877444 DOI: 10.1038/mtna.2015.35] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/22/2015] [Indexed: 01/02/2023]
Abstract
Major physiological changes are governed by alternative splicing of RNA, and its misregulation may lead to specific diseases. With the use of a genome-wide approach, we show here that this splicing step can be modified by medication and demonstrate the effects of the biguanide metformin, on alternative splicing. The mechanism of action involves AMPK activation and downregulation of the RBM3 RNA-binding protein. The effects of metformin treatment were tested on myotonic dystrophy type I (DM1), a multisystemic disease considered to be a spliceopathy. We show that this drug promotes a corrective effect on several splicing defects associated with DM1 in derivatives of human embryonic stem cells carrying the causal mutation of DM1 as well as in primary myoblasts derived from patients. The biological effects of metformin were shown to be compatible with typical therapeutic dosages in a clinical investigation involving diabetic patients. The drug appears to act as a modifier of alternative splicing of a subset of genes and may therefore have novel therapeutic potential for many more diseases besides those directly linked to defective alternative splicing.
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Affiliation(s)
| | | | | | - Emilie Chautard
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France.,Université Lyon 1, CNRS, UMR 5558, INRIA Bamboo, Villeurbanne, France
| | - Clara Benoit
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France
| | - Didier Auboeuf
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, Centre Léon Bérard, Lyon, France
| | - Anne Boland
- Centre National de Génotypage, Institut de Génomique, CEA, Evry, France
| | | | | | | | - Paule Bénit
- INSERM UMR 1141, Hôpital Robert Debré, Paris, France.,Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Pierre Rustin
- INSERM UMR 1141, Hôpital Robert Debré, Paris, France.,Université Paris 7, Faculté de Médecine Denis Diderot, Paris, France
| | - Sylvia Franc
- Centre Hospitalier Sud Francilien and CERITD, Evry Cedex, France
| | | | - Denis Furling
- Sorbonne Universités, UPMC Université Paris 06, Centre de Recherche en Myologie, INSERM UMRS974, CNRS FRE3617, Institut de Myologie, Paris 75013, France
| | - Guillaume Bassez
- GH Henri Mondor, Inserm U955, Université Paris Est, Créteil, France
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33
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Bebee TW, Park JW, Sheridan KI, Warzecha CC, Cieply BW, Rohacek AM, Xing Y, Carstens RP. The splicing regulators Esrp1 and Esrp2 direct an epithelial splicing program essential for mammalian development. eLife 2015; 4. [PMID: 26371508 PMCID: PMC4566030 DOI: 10.7554/elife.08954] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 08/18/2015] [Indexed: 12/13/2022] Open
Abstract
Tissue- and cell-type-specific regulators of alternative splicing (AS) are essential components of posttranscriptional gene regulation, necessary for normal cellular function, patterning, and development. Mice with ablation of Epithelial splicing regulatory protein (Esrp1) develop cleft lip and palate. Loss of both Esrp1 and its paralog Esrp2 results in widespread developmental defects with broad implications to human disease. Deletion of the Esrps in the epidermis revealed their requirement for establishing a proper skin barrier, a primary function of epithelial cells comprising the epidermis. We profiled the global Esrp-mediated splicing regulatory program in epidermis, which revealed large-scale programs of epithelial cell-type-specific splicing required for epithelial cell functions. These mice represent a valuable model for evaluating the essential role for AS in development and function of epithelial cells, which play essential roles in tissue homeostasis in numerous organs, and provide a genetic tool to evaluate important functional properties of epithelial-specific splice variants in vivo. DOI:http://dx.doi.org/10.7554/eLife.08954.001 Genes are turned into their protein products via two steps. The first, transcription, produces an intermediate RNA molecule or ‘transcript’; the second step, translation, turns the transcript into a protein. Most genes in mammals contain stretches of DNA called exons, which code for protein, interspersed with sequences called introns that do not. Therefore, a transcript must be ‘spliced’ before translation—the introns are removed and the exons joined. In some genes, certain exons can be optionally included or excluded from a transcript to produce different versions of the same protein that can often have very different functions. This is known as alternative splicing, and is essential for normal development. A large number of regulatory proteins control this process, many of which are only made in specific types of cells or tissues. Esrp1 and Esrp2 are two proteins that regulate alternative splicing in epithelial cells. These specialized cells form sheets that line most organs in the body and are found in the epidermis, the outermost layer of the skin. Although Esrp1 and Esrp2 have previously been studied in the laboratory using cultured cell lines, their roles have not been investigated in living animals. Bebee, Park et al. have now examined mice that are unable to produce one or both of these proteins. Mice that only lacked Esrp1 developed a cleft lip and palate. In mice that lacked both proteins, many organs failed to develop correctly and in some cases did not form at all. In the epidermis, the loss of Esrp1 and Esrp2 disrupted the splicing of the transcripts from genes that give epithelial cells many of their specialized characteristics, such as the ability to form sheets of cells with well formed junctions between them. This meant that epidermis that lacked Esrp1 and Esrp2 could not form a proper barrier layer, which is a crucial role of epithelia in skin as well as in other organs. In future, the mutant mice will be valuable for exploring how alternative splicing affects the development of epithelial cells and their properties. DOI:http://dx.doi.org/10.7554/eLife.08954.002
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Affiliation(s)
- Thomas W Bebee
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Juw Won Park
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
| | - Katherine I Sheridan
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Claude C Warzecha
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Benjamin W Cieply
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Alex M Rohacek
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
| | - Yi Xing
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States
| | - Russ P Carstens
- Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, United States
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Regulation of CD44E by DARPP-32-dependent activation of SRp20 splicing factor in gastric tumorigenesis. Oncogene 2015; 35:1847-56. [PMID: 26119931 PMCID: PMC4486340 DOI: 10.1038/onc.2015.250] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 05/11/2015] [Accepted: 05/22/2015] [Indexed: 12/19/2022]
Abstract
Objective CD44E is a frequently overexpressed variant of CD44 in gastric cancer. Mechanisms that regulate CD44 splicing and expression in gastric cancer remain unknown. Herein, we investigated the role of DARPP-32 (dopamine and cAMP-regulated phosphoprotein, Mr 32000) in promoting tumor growth through regulation of CD44 splicing. Design Quantitative luciferase reporter, quantitative real-time RT-PCR (qRT-PCR), Western blot, co-immunoprecipitation, ubiquitination, and tumor xenograft experiments were performed. Results Western blot and qRT-PCR results indicated that knockdown of endogenous DARPP-32 markedly reduces expression of CD44 V8-V10 (CD44E). Using a quantitative splicing luciferase reporter system, we detected a significant increase in the reporter activity following DARPP-32 overexpression (p < 0.001). Conversely, knocking down endogenous DARPP-32 significantly attenuated the splicing activity (p < 0.001). Further experiments showed that DARPP-32 regulates the expression of SRp20 splicing factor and co-exists with it in the same protein complex. Inhibition of alternative splicing with digitoxin followed by immunoprecipitation and immunoblotting indicated that DARPP-32 plays an important role in regulating SRp20 protein stability. The knockdown of endogenous DARPP-32 confirmed that DARPP-32 regulates the SRp20-dependent CD44E splicing. Using tumor xenograft mouse model, knocking down endogenous DARPP-32 markedly reduced SRp20 and CD44E protein levels with a decreased tumor growth. The reconstitution of SRp20 expression in these cells rescued tumor growth. In addition, we also demonstrated frequent co-overexpression and positive correlation of DARPP-32, SRp20 and CD44E expression levels in human gastric primary tumors. Conclusion Our novel findings establish for the first time the role of DARPP-32 in regulating splicing factors in gastric cancer cells. The DARPP-32–SRp20 axis plays a key role in regulating the CD44E splice variant that promotes gastric tumorigenesis.
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Platt C, Calimano M, Nemet J, Bubenik J, Cochrane A. Differential Effects of Tra2ß Isoforms on HIV-1 RNA Processing and Expression. PLoS One 2015; 10:e0125315. [PMID: 25970345 PMCID: PMC4430212 DOI: 10.1371/journal.pone.0125315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 03/16/2015] [Indexed: 12/03/2022] Open
Abstract
Balanced processing of HIV-1 RNA is critical to virus replication and is regulated by host factors. In this report, we demonstrate that overexpression of either Tra2α or Tra2β results in a marked reduction in HIV-1 Gag/ Env expression, an effect associated with changes in HIV-1 RNA accumulation, altered viral splice site usage, and a block to export of HIV-1 genomic RNA. A natural isoform of Tra2β (Tra2ß3), lacking the N-terminal RS domain, also suppressed HIV-1 expression but had different effects on viral RNA processing. The functional differences between the Tra2β isoforms were also observed in the context of another RNA substrate indicating that these factors have distinct functions within the cell. Finally, we demonstrate that Tra2ß depletion results in a selective reduction in HIV-1 Env expression as well as an increase in multiply spliced viral RNA. Together, the findings indicate that Tra2α/β can play important roles in regulating HIV-1 RNA metabolism and expression.
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MESH Headings
- Gene Expression Regulation
- HEK293 Cells
- HIV-1/genetics
- HIV-1/metabolism
- HeLa Cells
- Host-Pathogen Interactions
- Humans
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Protein Isoforms/antagonists & inhibitors
- Protein Isoforms/genetics
- Protein Isoforms/metabolism
- RNA Splice Sites
- RNA Splicing
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Small Interfering/genetics
- RNA, Small Interfering/metabolism
- RNA, Viral/genetics
- RNA, Viral/metabolism
- RNA-Binding Proteins/antagonists & inhibitors
- RNA-Binding Proteins/genetics
- RNA-Binding Proteins/metabolism
- Serine-Arginine Splicing Factors
- Signal Transduction
- Virus Replication
- env Gene Products, Human Immunodeficiency Virus/antagonists & inhibitors
- env Gene Products, Human Immunodeficiency Virus/genetics
- env Gene Products, Human Immunodeficiency Virus/metabolism
- gag Gene Products, Human Immunodeficiency Virus/antagonists & inhibitors
- gag Gene Products, Human Immunodeficiency Virus/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
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Affiliation(s)
- Craig Platt
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Maria Calimano
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Josip Nemet
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Jodi Bubenik
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
| | - Alan Cochrane
- Dept. of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- * E-mail:
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Abstract
Tra2 proteins regulate pre-mRNA splicing in vertebrates and invertebrates, and are involved in important processes ranging from brain development in mice to sex determination in fruitflies. In structure Tra2 proteins contain two RS domains (domains enriched in arginine and serine residues) flanking a central RRM (RNA recognition motif). Understanding the mechanisms of how Tra2 proteins work to control splicing is one of the key requirements to understand their biology. In the present article, we review what is known about how Tra2 proteins regulate splicing decisions in mammals and fruitflies.
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Lu ZX, Huang Q, Park JW, Shen S, Lin L, Tokheim CJ, Henry MD, Xing Y. Transcriptome-wide landscape of pre-mRNA alternative splicing associated with metastatic colonization. Mol Cancer Res 2015; 13:305-18. [PMID: 25274489 PMCID: PMC4336826 DOI: 10.1158/1541-7786.mcr-14-0366] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Metastatic colonization is an ominous feature of cancer progression. Recent studies have established the importance of pre-mRNA alternative splicing (AS) in cancer biology. However, little is known about the transcriptome-wide landscape of AS associated with metastatic colonization. Both in vitro and in vivo models of metastatic colonization were utilized to study AS regulation associated with cancer metastasis. Transcriptome profiling of prostate cancer cells and derivatives crossing in vitro or in vivo barriers of metastasis revealed splicing factors with significant gene expression changes associated with metastatic colonization. These include splicing factors known to be differentially regulated in epithelial-mesenchymal transition (ESRP1, ESRP2, and RBFOX2), a cellular process critical for cancer metastasis, as well as novel findings (NOVA1 and MBNL3). Finally, RNA-seq indicated a large network of AS events regulated by multiple splicing factors with altered gene expression or protein activity. These AS events are enriched for pathways important for cell motility and signaling, and affect key regulators of the invasive phenotype such as CD44 and GRHL1. IMPLICATIONS Transcriptome-wide remodeling of AS is an integral regulatory process underlying metastatic colonization, and AS events affect the metastatic behavior of cancer cells.
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Affiliation(s)
- Zhi-xiang Lu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Qin Huang
- Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa. Department of Pathology, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa
| | - Juw Won Park
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Shihao Shen
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Lan Lin
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Collin J Tokheim
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California
| | - Michael D Henry
- Department of Molecular Physiology and Biophysics, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa. Department of Pathology, Holden Comprehensive Cancer Center, University of Iowa, Iowa City, Iowa.
| | - Yi Xing
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, California.
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Pawellek A, McElroy S, Samatov T, Mitchell L, Woodland A, Ryder U, Gray D, Lührmann R, Lamond AI. Identification of small molecule inhibitors of pre-mRNA splicing. J Biol Chem 2014; 289:34683-98. [PMID: 25281741 PMCID: PMC4263873 DOI: 10.1074/jbc.m114.590976] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/02/2014] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic pre-mRNA splicing is an essential step in gene expression for all genes that contain introns. In contrast to transcription and translation, few well characterized chemical inhibitors are available with which to dissect the splicing process, particularly in cells. Therefore, the identification of specific small molecules that either inhibit or modify pre-mRNA splicing would be valuable for research and potentially also for therapeutic applications. We have screened a highly curated library of 71,504 drug-like small molecules using a high throughput in vitro splicing assay. This identified 10 new compounds that both inhibit pre-mRNA splicing in vitro and modify splicing of endogenous pre-mRNA in cells. One of these splicing modulators, DDD00107587 (termed "madrasin," i.e. 2-((7methoxy-4-methylquinazolin-2-yl)amino)-5,6-dimethylpyrimidin-4(3H)-one RNAsplicing inhibitor), was studied in more detail. Madrasin interferes with the early stages of spliceosome assembly and stalls spliceosome assembly at the A complex. Madrasin is cytotoxic at higher concentrations, although at lower concentrations it induces cell cycle arrest, promotes a specific reorganization of subnuclear protein localization, and modulates splicing of multiple pre-mRNAs in both HeLa and HEK293 cells.
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Affiliation(s)
| | - Stuart McElroy
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Timur Samatov
- the Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Lee Mitchell
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Andrew Woodland
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Ursula Ryder
- From the Centre of Gene Regulation and Expression and
| | - David Gray
- the Drug Discovery Unit, University of Dundee, Dundee DD1 5EH, Scotland, United Kingdom and
| | - Reinhard Lührmann
- the Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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Guo R, Zheng L, Park JW, Lv R, Chen H, Jiao F, Xu W, Mu S, Wen H, Qiu J, Wang Z, Yang P, Wu F, Hui J, Fu X, Shi X, Shi YG, Xing Y, Lan F, Shi Y. BS69/ZMYND11 reads and connects histone H3.3 lysine 36 trimethylation-decorated chromatin to regulated pre-mRNA processing. Mol Cell 2014; 56:298-310. [PMID: 25263594 DOI: 10.1016/j.molcel.2014.08.022] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Revised: 07/28/2014] [Accepted: 08/21/2014] [Indexed: 11/26/2022]
Abstract
BS69 (also called ZMYND11) contains tandemly arranged PHD, BROMO, and PWWP domains, which are chromatin recognition modalities. Here, we show that BS69 selectively recognizes histone variant H3.3 lysine 36 trimethylation (H3.3K36me3) via its chromatin-binding domains. We further identify BS69 association with RNA splicing regulators, including the U5 snRNP components of the spliceosome, such as EFTUD2. Remarkably, RNA sequencing shows that BS69 mainly regulates intron retention (IR), which is the least understood RNA alternative splicing event in mammalian cells. Biochemical and genetic experiments demonstrate that BS69 promotes IR by antagonizing EFTUD2 through physical interactions. We further show that regulation of IR by BS69 also depends on its binding to H3K36me3-decorated chromatin. Taken together, our study identifies an H3.3K36me3-specific reader and a regulator of IR and reveals that BS69 connects histone H3.3K36me3 to regulated RNA splicing, providing significant, important insights into chromatin regulation of pre-mRNA processing.
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Affiliation(s)
- Rui Guo
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Lijuan Zheng
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Juw Won Park
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CHS 33-228, 650 Charles E. Young Drive South, Los Angeles, CA 90095-7278, USA
| | - Ruitu Lv
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Hao Chen
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Fangfang Jiao
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Wenqi Xu
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Shirong Mu
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Hong Wen
- Department of Molecular Carcinogenesis and Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Genes and Development Graduate Program, The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Jinsong Qiu
- Department of Cellular and Molecular Medicine, The Palade Laboratories, Room 231, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA
| | - Zhentian Wang
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Pengyuan Yang
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Feizhen Wu
- Epigenetics Laboratory, School of Basic Medicine and Institutes of Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Jingyi Hui
- State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
| | - Xiangdong Fu
- Department of Cellular and Molecular Medicine, The Palade Laboratories, Room 231, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA
| | - Xiaobing Shi
- Department of Molecular Carcinogenesis and Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Genes and Development Graduate Program, The University of Texas Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Yujiang Geno Shi
- Endocrinology Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Epigenetics Laboratory, Institutes of Biomedical Sciences and School of Basic Medicine, Shanghai Medical College of Fudan University, Shanghai 200032, China
| | - Yi Xing
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, CHS 33-228, 650 Charles E. Young Drive South, Los Angeles, CA 90095-7278, USA.
| | - Fei Lan
- Epigenetics Laboratory, Institutes of Biomedical Sciences and School of Basic Medicine, Shanghai Medical College of Fudan University, Shanghai 200032, China.
| | - Yang Shi
- Epigenetics Laboratory, Institutes of Biomedical Sciences and School of Basic Medicine, Shanghai Medical College of Fudan University, Shanghai 200032, China; Division of Newborn Medicine and Program in Epigenetics, Department of Medicine, Boston Children's Hospital, Boston, MA 02115, USA; Department of Cell Biology, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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40
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Best A, James K, Dalgliesh C, Hong E, Kheirolahi-Kouhestani M, Curk T, Xu Y, Danilenko M, Hussain R, Keavney B, Wipat A, Klinck R, Cowell IG, Cheong Lee K, Austin CA, Venables JP, Chabot B, Santibanez Koref M, Tyson-Capper A, Elliott DJ. Human Tra2 proteins jointly control a CHEK1 splicing switch among alternative and constitutive target exons. Nat Commun 2014; 5:4760. [PMID: 25208576 PMCID: PMC4175592 DOI: 10.1038/ncomms5760] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/22/2014] [Indexed: 01/11/2023] Open
Abstract
Alternative splicing--the production of multiple messenger RNA isoforms from a single gene--is regulated in part by RNA binding proteins. While the RBPs transformer2 alpha (Tra2α) and Tra2β have both been implicated in the regulation of alternative splicing, their relative contributions to this process are not well understood. Here we find simultaneous--but not individual--depletion of Tra2α and Tra2β induces substantial shifts in splicing of endogenous Tra2β target exons, and that both constitutive and alternative target exons are under dual Tra2α-Tra2β control. Target exons are enriched in genes associated with chromosome biology including CHEK1, which encodes a key DNA damage response protein. Dual Tra2 protein depletion reduces expression of full-length CHK1 protein, results in the accumulation of the DNA damage marker γH2AX and decreased cell viability. We conclude Tra2 proteins jointly control constitutive and alternative splicing patterns via paralog compensation to control pathways essential to the maintenance of cell viability.
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Affiliation(s)
- Andrew Best
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Katherine James
- School of Computing Science, Claremont Tower, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Caroline Dalgliesh
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Elaine Hong
- Institute for Cellular Medicine, Newcastle University, Framlington Place, Newcastle NE2 4HH, UK
| | | | - Tomaz Curk
- Faculty of Computer and Information Science, University of Ljubljana, Trzaska cesta 25, SI-1000, Ljubljana, Slovenia
| | - Yaobo Xu
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Marina Danilenko
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Rafiq Hussain
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Bernard Keavney
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
- Institute of Cardiovascular Sciences, The University of Manchester, Manchester M13 9NT, UK
| | - Anil Wipat
- School of Computing Science, Claremont Tower, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
| | - Roscoe Klinck
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada J1E 4K8
| | - Ian G. Cowell
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle NE2 4HH, UK
| | - Ka Cheong Lee
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle NE2 4HH, UK
| | - Caroline A. Austin
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle NE2 4HH, UK
| | - Julian P. Venables
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Benoit Chabot
- Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Québec, Canada J1E 4K8
| | - Mauro Santibanez Koref
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
| | - Alison Tyson-Capper
- Institute for Cellular Medicine, Newcastle University, Framlington Place, Newcastle NE2 4HH, UK
| | - David J. Elliott
- Institute of Genetic Medicine, Newcastle University, Central Parkway, Newcastle NE1 3BZ, UK
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Multiple effects of digoxin on subsets of cancer-associated genes through the alternative splicing pathway. Biochimie 2014; 106:131-9. [PMID: 25193633 DOI: 10.1016/j.biochi.2014.08.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/20/2014] [Indexed: 12/25/2022]
Abstract
The signaling characteristics of Na(+)/K(+)-ATPase are distinct from its ion pumping activity. Cardiac glycosides modulate the Na(+)/K(+)-ATPase protein complex upon binding, activate downstream signaling pathways and increase [Ca(2+)]i. Recent studies demonstrate that the depletion of p53 and hypoxia-induced factor 1α proteins is caused by cardiac glycosides. However, the detailed mechanisms governing this process are not well known. In this study, we showed that the depletion of p53 proteins by digoxin involved not only inhibition of protein synthesis but also inhibition at the post-transcriptional level. Post-transcriptional regulation occurs via down-regulation of SRSF3, the primary splicing factor responsible for the switch from p53α to the p53β isoform. Digoxin also modulated G2/M arrest, DNA damage and apoptosis through the p53-dependent pathway in HeLa cells. In addition, digoxin was involved in epithelial-mesenchymal-transition progression via E-cadherin reduction and snail induction. Digoxin had similar effects to caffeine, another SRSF3-reduced agent, on the cell cycle profile and DNA damage of cells. Interestingly, combined digoxin and caffeine treatment blocked cell cycle progression and conferred resistance to cell death via snail induction. These findings demonstrate that down-regulation of splicing factor, such as SRSF3, to alter cell cycle progression, cell death and invasion is a potential target for the drug repositioning of cardiac glycosides.
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HuR regulates alternative splicing of the TRA2β gene in human colon cancer cells under oxidative stress. Mol Cell Biol 2014; 34:2857-73. [PMID: 24865968 DOI: 10.1128/mcb.00333-14] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Hu antigen R (HuR) regulates stress responses through stabilizing and/or facilitating the translation of target mRNAs. The human TRA2β gene encodes splicing factor transformer 2β (Tra2β) and generates 5 mRNA isoforms (TRA2β1 to -5) through alternative splicing. Exposure of HCT116 colon cancer cells to sodium arsenite stimulated checkpoint kinase 2 (Chk2)- and mitogen-activated protein kinase p38 (p38(MAPK))-mediated phosphorylation of HuR at positions S88 and T118. This induced an association between HuR and the 39-nucleotide (nt) proximal region of TRA2β exon 2, generating a TRA2β4 mRNA that includes exon 2, which has multiple premature stop codons. HuR knockdown or Chk2/p38(MAPK) double knockdown inhibited the arsenite-stimulated production of TRA2β4 and increased Tra2β protein, facilitating Tra2β-dependent inclusion of exons in target pre-mRNAs. The effects of HuR knockdown or Chk2/p38(MAPK) double knockdown were also confirmed using a TRA2β minigene spanning exons 1 to 4, and the effects disappeared when the 39-nt region was deleted from the minigene. In endogenous HuR knockdown cells, the overexpression of a HuR mutant that could not be phosphorylated (with changes of serine to alanine at position 88 [S88A], S100A, and T118A) blocked the associated TRA2β4 interaction and TRA2β4 generation, while the overexpression of a phosphomimetic HuR (with mutations S88D, S100D, and T118D) restored the TRA2β4-related activities. Our findings revealed the potential role of nuclear HuR in the regulation of alternative splicing programs under oxidative stress.
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Roberts JM, Ennajdaoui H, Edmondson C, Wirth B, Sanford J, Chen B. Splicing factor TRA2B is required for neural progenitor survival. J Comp Neurol 2014; 522:372-92. [PMID: 23818142 PMCID: PMC3855887 DOI: 10.1002/cne.23405] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 06/20/2013] [Accepted: 06/21/2013] [Indexed: 01/08/2023]
Abstract
Alternative splicing of pre-mRNAs can rapidly regulate the expression of large groups of proteins. The RNA binding protein TRA2B (SFRS10) plays well-established roles in developmentally regulated alternative splicing during Drosophila sexual differentiation. TRA2B is also essential for mammalian embryogenesis and is implicated in numerous human diseases. Precise regulation of alternative splicing is critical to the development and function of the central nervous system; however, the requirements for specific splicing factors in neurogenesis are poorly understood. This study focuses on the role of TRA2B in mammalian brain development. We show that, during murine cortical neurogenesis, TRA2B is expressed in both neural progenitors and cortical projection neurons. Using cortex-specific Tra2b mutant mice, we show that TRA2B depletion results in apoptosis of the neural progenitor cells as well as disorganization of the cortical plate. Thus, TRA2B is essential for proper development of the cerebral cortex.
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Affiliation(s)
- Jacqueline M Roberts
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Hanane Ennajdaoui
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Carina Edmondson
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Brunhilde Wirth
- Institute of Human Genetics, Institute for Genetics and Center for Molecular Medicine Cologne, University of Cologne, Cologne 50931, Germany
| | - Jeremy Sanford
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | - Bin Chen
- Department of Molecular, Cell, and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
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44
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Lu GY, Huang SM, Liu ST, Liu PY, Chou WY, Lin WS. Caffeine induces tumor cytotoxicity via the regulation of alternative splicing in subsets of cancer-associated genes. Int J Biochem Cell Biol 2013; 47:83-92. [PMID: 24333670 DOI: 10.1016/j.biocel.2013.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 11/23/2013] [Accepted: 12/03/2013] [Indexed: 12/11/2022]
Abstract
Caffeine causes a diverse range of pharmacological effects that are time- and concentration-dependent and reversible. The detailed mechanisms of caffeine in tumor suppression via tumor suppressor protein p53 remain unclear. The isoforms of p53 are physiological proteins that are expressed in normal cells and generated via alternative promoters, splicing sites and/or translational initiation sites. In this study, we investigated how caffeine modulated cell cycle arrest and apoptosis via the expression of various alternatively spliced p53 isoforms. Caffeine reduced p53α expression and induced the expression of p53β, which contains an alternatively spliced p53 C-terminus. In HeLa cells, the expression levels of many serine/arginine-rich splicing factors, including serine/arginine-rich splicing factors 2 and 3, were altered by caffeine. Serine/arginine-rich splicing factor 3 was a promising candidate for the serine/arginine-rich splicing factors responsible for the alternative splicing of p53 in response to caffeine treatment. In addition to p53-dependent functions, multiple target genes of serine/arginine-rich splicing factor 3 suggest that caffeine can regulate epithelial-mesenchymal-transition and hypoxic conditions to inhibit the survival of tumor cells. In summary, our data provide a new pathway of caffeine-modulated tumor suppression via the alternative splicing of the target genes of serine/arginine-rich splicing factor 3.
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Affiliation(s)
- Guan-Yu Lu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei City 114, Taiwan, ROC; Department of Pharmacy, Shalu Division, Kuang Tien General Hospital, Taichung 433, Taiwan, ROC
| | - Shih-Ming Huang
- Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, ROC
| | - Shu-Ting Liu
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei City 114, Taiwan, ROC; Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, ROC
| | - Pei-Yao Liu
- Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, ROC
| | - Wei-Yuan Chou
- Department of Biochemistry, National Defense Medical Center, Taipei City 114, Taiwan, ROC
| | - Wei-Shiang Lin
- Graduate Institute of Medical Sciences, National Defense Medical Center, Taipei City 114, Taiwan, ROC; Division of Cardiology, Department of Medicine, Tri-Service General Hospital, National Defense Medical Center, Taipei City 114, Taiwan, ROC.
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45
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Laird GM, Eisele EE, Rabi SA, Nikolaeva D, Siliciano RF. A novel cell-based high-throughput screen for inhibitors of HIV-1 gene expression and budding identifies the cardiac glycosides. J Antimicrob Chemother 2013; 69:988-94. [PMID: 24275119 DOI: 10.1093/jac/dkt471] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
OBJECTIVES Highly active antiretroviral therapy (HAART) is the mainstay of treatment for HIV-1 infection. While current HAART regimens have been extremely effective, issues of associated toxicity, cost and resistance remain and there is a need for novel antiretroviral compounds to complement the existing therapy. We sought to develop a novel high-throughput method for identifying compounds that block later steps in the life cycle not targeted by current therapy. METHODS We designed a high-throughput screen to identify inhibitors of post-integration steps in the HIV-1 life cycle. The screening method was applied to a library of compounds that included numerous FDA-approved small molecules. RESULTS Among the small molecules that inhibited late stages in HIV-1 replication were members of the cardiac glycoside family. We demonstrate that cardiac glycosides potently inhibit HIV-1 gene expression, thereby reducing the production of infectious HIV-1. We demonstrate that this inhibition is dependent upon the human Na(+)/K(+)-ATPase, but independent of cardiac glycoside-induced increases in intracellular Ca(2+). CONCLUSIONS We have validated a novel high-throughput screen to identify small molecule inhibitors of HIV-1 gene expression, virion assembly and budding. Using this screen, we have demonstrated that a number of FDA-approved compounds developed for other purposes potently inhibit HIV-1 replication, including the cardiac glycosides. Our work indicates that the entire cardiac glycoside family of drugs shows potential for antiretroviral drug development.
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Affiliation(s)
- Gregory M Laird
- Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
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Ames EG, Lawson MJ, Mackey AJ, Holmes JW. Sequencing of mRNA identifies re-expression of fetal splice variants in cardiac hypertrophy. J Mol Cell Cardiol 2013; 62:99-107. [PMID: 23688780 DOI: 10.1016/j.yjmcc.2013.05.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 05/06/2013] [Accepted: 05/09/2013] [Indexed: 02/07/2023]
Abstract
Cardiac hypertrophy has been well-characterized at the level of transcription. During cardiac hypertrophy, genes normally expressed primarily during fetal heart development are re-expressed, and this fetal gene program is believed to be a critical component of the hypertrophic process. Recently, alternative splicing of mRNA transcripts has been shown to be temporally regulated during heart development, leading us to consider whether fetal patterns of splicing also reappear during hypertrophy. We hypothesized that patterns of alternative splicing occurring during heart development are recapitulated during cardiac hypertrophy. Here we present a study of isoform expression during pressure-overload cardiac hypertrophy induced by 10 days of transverse aortic constriction (TAC) in rats and in developing fetal rat hearts compared to sham-operated adult rat hearts, using high-throughput sequencing of poly(A) tail mRNA. We find a striking degree of overlap between the isoforms expressed differentially in fetal and pressure-overloaded hearts compared to control: forty-four percent of the isoforms with significantly altered expression in TAC hearts are also expressed at significantly different levels in fetal hearts compared to control (P<0.001). The isoforms that are shared between hypertrophy and fetal heart development are significantly enriched for genes involved in cytoskeletal organization, RNA processing, developmental processes, and metabolic enzymes. Our data strongly support the concept that mRNA splicing patterns normally associated with heart development recur as part of the hypertrophic response to pressure overload. These findings suggest that cardiac hypertrophy shares post-transcriptional as well as transcriptional regulatory mechanisms with fetal heart development.
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Affiliation(s)
- E G Ames
- Department of Biomedical Engineering, University of Virginia, Health System Box 800759, Charlottesville, VA 22908, USA.
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Havens MA, Duelli DM, Hastings ML. Targeting RNA splicing for disease therapy. WILEY INTERDISCIPLINARY REVIEWS. RNA 2013; 4:247-66. [PMID: 23512601 PMCID: PMC3631270 DOI: 10.1002/wrna.1158] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Splicing of pre-messenger RNA into mature messenger RNA is an essential step for the expression of most genes in higher eukaryotes. Defects in this process typically affect cellular function and can have pathological consequences. Many human genetic diseases are caused by mutations that cause splicing defects. Furthermore, a number of diseases are associated with splicing defects that are not attributed to overt mutations. Targeting splicing directly to correct disease-associated aberrant splicing is a logical approach to therapy. Splicing is a favorable intervention point for disease therapeutics, because it is an early step in gene expression and does not alter the genome. Significant advances have been made in the development of approaches to manipulate splicing for therapy. Splicing can be manipulated with a number of tools including antisense oligonucleotides, modified small nuclear RNAs (snRNAs), trans-splicing, and small molecule compounds, all of which have been used to increase specific alternatively spliced isoforms or to correct aberrant gene expression resulting from gene mutations that alter splicing. Here we describe clinically relevant splicing defects in disease states, the current tools used to target and alter splicing, specific mutations and diseases that are being targeted using splice-modulating approaches, and emerging therapeutics.
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Affiliation(s)
- Mallory A. Havens
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science. North Chicago, IL, 60064, USA. No conflicts of interest
| | - Dominik M. Duelli
- Department of Cellular and Molecular Pharmacology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, 60064, USA. No conflicts of interest
| | - Michelle L. Hastings
- Department of Cell Biology and Anatomy, Chicago Medical School, Rosalind Franklin University of Medicine and Science. North Chicago, IL, 60064, USA, Phone: 847-578-8517 Fax: 847-578-3253. No conflicts of interest
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48
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Shen M, Bellaousov S, Hiller M, de La Grange P, Creamer TP, Malina O, Sperling R, Mathews DH, Stoilov P, Stamm S. Pyrvinium pamoate changes alternative splicing of the serotonin receptor 2C by influencing its RNA structure. Nucleic Acids Res 2013; 41:3819-32. [PMID: 23393189 PMCID: PMC3616728 DOI: 10.1093/nar/gkt063] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2012] [Revised: 01/08/2013] [Accepted: 01/15/2013] [Indexed: 01/17/2023] Open
Abstract
The serotonin receptor 2C plays a central role in mood and appetite control. It undergoes pre-mRNA editing as well as alternative splicing. The RNA editing suggests that the pre-mRNA forms a stable secondary structure in vivo. To identify substances that promote alternative exons inclusion, we set up a high-throughput screen and identified pyrvinium pamoate as a drug-promoting exon inclusion without editing. Circular dichroism spectroscopy indicates that pyrvinium pamoate binds directly to the pre-mRNA and changes its structure. SHAPE (selective 2'-hydroxyl acylation analysed by primer extension) assays show that part of the regulated 5'-splice site forms intramolecular base pairs that are removed by this structural change, which likely allows splice site recognition and exon inclusion. Genome-wide analyses show that pyrvinium pamoate regulates >300 alternative exons that form secondary structures enriched in A-U base pairs. Our data demonstrate that alternative splicing of structured pre-mRNAs can be regulated by small molecules that directly bind to the RNA, which is reminiscent to an RNA riboswitch.
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MESH Headings
- Alternative Splicing/drug effects
- Base Sequence
- Exons
- HEK293 Cells
- High-Throughput Screening Assays
- Humans
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phylogeny
- Pyrvinium Compounds/metabolism
- Pyrvinium Compounds/pharmacology
- RNA Editing
- RNA Precursors/metabolism
- RNA, Double-Stranded/chemistry
- RNA, Double-Stranded/drug effects
- RNA, Messenger/chemistry
- RNA, Messenger/drug effects
- RNA, Messenger/metabolism
- Receptor, Serotonin, 5-HT2C/genetics
- Receptor, Serotonin, 5-HT2C/metabolism
- Ribonucleoprotein, U1 Small Nuclear/metabolism
- Spliceosomes/metabolism
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Affiliation(s)
- Manli Shen
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Stanislav Bellaousov
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Michael Hiller
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Pierre de La Grange
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Trevor P. Creamer
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Orit Malina
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Ruth Sperling
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - David H. Mathews
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Peter Stoilov
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
| | - Stefan Stamm
- Department of Molecular and Cellular Biochemistry, University of Kentucky, 741 South Limestone, Lexington, KY 40536, USA, Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany and Max Planck Institute for the Physics of Complex Systems, 01187 Dresden, Germany GenoSplice technology, Hôpital Saint-Louis, 1 avenue Claude Vellefaux, 75010 Paris, France, Department of Biochemistry and Biophysics,University of Rochester Medical Center, University of Rochester, Rochester, NY 14642, USA, Department of Biochemistry, West Virginia University, Morgantown, P.O. Box 9142, WV 26506, USA, Department of Genetics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel and Center for Structural Biology, University of Kentucky, Lexington, Kentucky 40536, USA
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Wong RW, Balachandran A, Ostrowski MA, Cochrane A. Digoxin suppresses HIV-1 replication by altering viral RNA processing. PLoS Pathog 2013; 9:e1003241. [PMID: 23555254 PMCID: PMC3610647 DOI: 10.1371/journal.ppat.1003241] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 01/24/2013] [Indexed: 11/18/2022] Open
Abstract
To develop new approaches to control HIV-1 replication, we examined the capacity of recently described small molecular modulators of RNA splicing for their effects on viral RNA metabolism. Of the drugs tested, digoxin was found to induce a dramatic inhibition of HIV-1 structural protein synthesis, a response due, in part, to reduced accumulation of the corresponding viral mRNAs. In addition, digoxin altered viral RNA splice site use, resulting in loss of the essential viral factor Rev. Digoxin induced changes in activity of the CLK family of SR protein kinases and modification of several SR proteins, including SRp20 and Tra2β, which could account for the effects observed. Consistent with this hypothesis, overexpression of SRp20 elicited changes in HIV-1 RNA processing similar to those observed with digoxin. Importantly, digoxin was also highly active against clinical strains of HIV-1 in vitro, validating this novel approach to treatment of this infection.
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Affiliation(s)
- Raymond W. Wong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Canada
| | | | | | - Alan Cochrane
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
- * E-mail:
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50
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Abstract
Several bacterial fermentation products and their synthetic derivatives display antitumour activities and bind tightly to components of the spliceosome, which is the complex molecular machinery involved in the removal of introns from mRNA precursors in eukaryotic cells. The drugs alter gene expression, including alternative splicing, of genes that are important for cancer progression. A flurry of recent reports has revealed that genes encoding splicing factors, including the drug target splicing factor 3B subunit 1 (SF3B1), are among the most highly mutated in various haematological malignancies such as chronic lymphocytic leukaemia and myelodysplastic syndromes. These observations highlight the role of splicing factors in cancer and suggest that an understanding of the molecular effects of drugs targeting these proteins could open new perspectives for studies of the spliceosome and its role in cancer progression, and for the development of novel antitumour therapies.
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