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Huang C, Hsu C, Chao M, Hsu K, Lin TE, Yen S, Tu H, Pan S. In silico identification of a novel Cdc2-like kinase 2 (CLK2) inhibitor in triple negative breast cancer. Protein Sci 2024; 33:e5004. [PMID: 38723164 PMCID: PMC11081522 DOI: 10.1002/pro.5004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 03/29/2024] [Accepted: 04/12/2024] [Indexed: 05/13/2024]
Abstract
Dysregulation of RNA splicing processes is intricately linked to tumorigenesis in various cancers, especially breast cancer. Cdc2-like kinase 2 (CLK2), an oncogenic RNA-splicing kinase pivotal in breast cancer, plays a significant role, particularly in the context of triple-negative breast cancer (TNBC), a subtype marked by substantial medical challenges due to its low survival rates. In this study, we employed a structure-based virtual screening (SBVS) method to identify potential CLK2 inhibitors with novel chemical structures for treating TNBC. Compound 670551 emerged as a novel CLK2 inhibitor with a 50% inhibitory concentration (IC50) value of 619.7 nM. Importantly, Compound 670551 exhibited high selectivity for CLK2 over other protein kinases. Functionally, this compound significantly reduced the survival and proliferation of TNBC cells. Results from a cell-based assay demonstrated that this inhibitor led to a decrease in RNA splicing proteins, such as SRSF4 and SRSF6, resulting in cell apoptosis. In summary, we identified a novel CLK2 inhibitor as a promising potential treatment for TNBC therapy.
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Affiliation(s)
- Cheng‐Chiao Huang
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia SinicaTaipeiTaiwan
- Division of General Surgery, Department of SurgeryTaipei Medical University HospitalTaipeiTaiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
| | - Chia‐Ming Hsu
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
| | - Min‐Wu Chao
- School of Medicine, College of Medicine, National Sun Yat‐sen UniversityKaohsiungTaiwan
- Institute of Biopharmaceutical Sciences, College of Medicine, National Sun Yat‐sen UniversityKaohsiungTaiwan
- The Doctoral Program of Clinical and Experimental Medicine, College of Medicine, National Sun Yat‐sen UniversityKaohsiungTaiwan
| | - Kai‐Cheng Hsu
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia SinicaTaipeiTaiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
- Ph.D. Program in Drug Discovery and Development IndustryCollege of Pharmacy, Taipei Medical UniversityTaipeiTaiwan
- TMU Research Center of Cancer Translational Medicine, Taipei Medical UniversityTaipeiTaiwan
- TMU Research Center of Drug Discovery, Taipei Medical UniversityTaipeiTaiwan
| | - Tony Eight Lin
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia SinicaTaipeiTaiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
| | - Shih‐Chung Yen
- Warshel Institute for Computational Biology, The Chinese University of Hong Kong (Shenzhen)ShenzhenGuangdongChina
| | - Huang‐Ju Tu
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
| | - Shiow‐Lin Pan
- Ph.D. Program for Cancer Molecular Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical University and Academia SinicaTaipeiTaiwan
- Graduate Institute of Cancer Biology and Drug Discovery, College of Medical Science and Technology, Taipei Medical UniversityTaipeiTaiwan
- Ph.D. Program in Drug Discovery and Development IndustryCollege of Pharmacy, Taipei Medical UniversityTaipeiTaiwan
- TMU Research Center of Cancer Translational Medicine, Taipei Medical UniversityTaipeiTaiwan
- TMU Research Center of Drug Discovery, Taipei Medical UniversityTaipeiTaiwan
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Rodríguez-Piña AL, Castaño de la Serna E, Jiménez-Bremont JF. The serine-arginine (SR) protein UmRrm75 from Ustilago maydis is a functional ortholog of yeast ScHrb1. Int Microbiol 2024; 27:819-830. [PMID: 37776379 DOI: 10.1007/s10123-023-00432-3] [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: 02/07/2023] [Revised: 08/09/2023] [Accepted: 09/16/2023] [Indexed: 10/02/2023]
Abstract
The Basidiomycete fungus Ustilago maydis is a biotrophic pathogen of maize. The U. maydis UmRrm75 gene encodes an RNA-binding protein (RBP). In a previous study, we reported that ΔUmRrm75 null mutant strains accumulate H2O2, exhibit slow growth, and have decreased virulence in maize. Herein, we describe UmRrm75 as an ortholog of the ScHrb1, a serine-arginine (SR) protein identified in the yeast Saccharomyces cerevisiae, which plays a role in nuclear quality control, specifically in mRNA splicing and export processes. The yeast ScHrb1 mutant (ΔScHrb1) exhibits an increased sensitivity to elevated levels of boron. We noticed that the ΔScHrb1 displayed sensitivity to H2O2, which is consistent with previous findings in the ΔUmRrm75 mutant. We reversed the sensitivity phenotypes of boron and H2O2 by introducing the UmRrm75 gene into the ΔScHrb1 mutant. Furthermore, we generated complementary strains of U. maydis by expressing UmRrm75-GFP under its native promoter in the ∆UmRrm75 mutants. The UmRrm75-GFP/∆UmRrm75 complementary strains successfully recovered their growth capability under stressors, H2O2 and boron, resembling the parental strains FB2 and AB33. The subcellular localization experiments conducted in U. maydis revealed that the UmRrm75 protein is localized within the nucleus of both yeast and hyphae. The nuclear localization of the UmRrm75 protein remains unaltered even under conditions of heat or oxidative stress. This suggests that UmRrm75 might perform its RBP activity in the nucleus, as previously reported for ScHrb1. Our data contribute to understanding the role of the nuclear RBP UmRrm75 from the corn smut fungus U. maydis.
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Affiliation(s)
- Alma Laura Rodríguez-Piña
- Laboratorio de Biotecnología Molecular Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica A.C., San Luis Potosi, San Luis Potosi, Mexico
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán A.C., Merida, Yucatan, Mexico
| | - Enrique Castaño de la Serna
- Unidad de Bioquímica y Biología Molecular de Plantas, Centro de Investigación Científica de Yucatán A.C., Merida, Yucatan, Mexico
| | - Juan Francisco Jiménez-Bremont
- Laboratorio de Biotecnología Molecular Plantas, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica A.C., San Luis Potosi, San Luis Potosi, Mexico.
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Segovia D, Adams DW, Hoffman N, Safaric Tepes P, Wee TL, Cifani P, Joshua-Tor L, Krainer AR. SRSF1 interactome determined by proximity labeling reveals direct interaction with spliceosomal RNA helicase DDX23. Proc Natl Acad Sci U S A 2024; 121:e2322974121. [PMID: 38743621 PMCID: PMC11126954 DOI: 10.1073/pnas.2322974121] [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: 01/03/2024] [Accepted: 04/15/2024] [Indexed: 05/16/2024] Open
Abstract
SRSF1 is the founding member of the SR protein family. It is required-interchangeably with other SR proteins-for pre-mRNA splicing in vitro, and it regulates various alternative splicing events. Dysregulation of SRSF1 expression contributes to cancer and other pathologies. Here, we characterized SRSF1's interactome using proximity labeling and mass spectrometry. This approach yielded 190 proteins enriched in the SRSF1 samples, independently of the N- or C-terminal location of the biotin-labeling domain. The detected proteins reflect established functions of SRSF1 in pre-mRNA splicing and reveal additional connections to spliceosome proteins, in addition to other recently identified functions. We validated a robust interaction with the spliceosomal RNA helicase DDX23/PRP28 using bimolecular fluorescence complementation and in vitro binding assays. The interaction is mediated by the N-terminal RS-like domain of DDX23 and both RRM1 and the RS domain of SRSF1. During pre-mRNA splicing, DDX23's ATPase activity is essential for the pre-B to B spliceosome complex transition and for release of U1 snRNP from the 5' splice site. We show that the RS-like region of DDX23's N-terminal domain is important for spliceosome incorporation, while larger deletions in this domain alter subnuclear localization. We discuss how the identified interaction of DDX23 with SRSF1 and other SR proteins may be involved in the regulation of these processes.
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Affiliation(s)
- Danilo Segovia
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
- Graduate Program in Molecular and Cellular Biology, Stony Brook University, Stony Brook, NY11794
| | - Dexter W. Adams
- HHMI, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
- W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
- Graduate Program in Genetics, Stony Brook University, Stony Brook, NY11794
| | | | | | - Tse-Luen Wee
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
| | - Paolo Cifani
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
| | - Leemor Joshua-Tor
- HHMI, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
- W. M. Keck Structural Biology Laboratory, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY11724
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Wu J, Niu L, Yang K, Xu J, Zhang D, Ling J, Xia P, Wu Y, Liu X, Liu J, Zhang J, Yu P. The role and mechanism of RNA-binding proteins in bone metabolism and osteoporosis. Ageing Res Rev 2024; 96:102234. [PMID: 38367813 DOI: 10.1016/j.arr.2024.102234] [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: 10/11/2023] [Revised: 02/06/2024] [Accepted: 02/13/2024] [Indexed: 02/19/2024]
Abstract
Osteoporosis is a prevalent chronic metabolic bone disease that poses a significant risk of fractures or mortality in elderly individuals. Its pathophysiological basis is often attributed to postmenopausal estrogen deficiency and natural aging, making the progression of primary osteoporosis among elderly people, especially older women, seemingly inevitable. The treatment and prevention of osteoporosis progression have been extensively discussed. Recently, as researchers delve deeper into the molecular biological mechanisms of bone remodeling, they have come to realize the crucial role of posttranscriptional gene control in bone metabolism homeostasis. RNA-binding proteins, as essential actors in posttranscriptional activities, may exert influence on osteoporosis progression by regulating the RNA life cycle. This review compiles recent findings on the involvement of RNA-binding proteins in abnormal bone metabolism in osteoporosis and describes the impact of some key RNA-binding proteins on bone metabolism regulation. Additionally, we explore the potential and rationale for modulating RNA-binding proteins as a means of treating osteoporosis, with an overview of drugs that target these proteins.
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Affiliation(s)
- Jiaqiang Wu
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China; Department of General Surgery, First Medical Center of the Chinese PLA General Hospital, Beijing, China
| | - Liyan Niu
- HuanKui College of Nanchang University, Nanchang 330006, China
| | - Kangping Yang
- The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang 330006, China
| | - Jingdong Xu
- Queen Mary College of Nanchang University, Nanchang 330006, China
| | - Deju Zhang
- Food and Nutritional Sciences, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, 999077, Hong Kong, China
| | - Jitao Ling
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Panpan Xia
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Yuting Wu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Xiao Liu
- Department of Cardiology, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou 510275, China
| | - Jianping Liu
- Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China
| | - Jing Zhang
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; Department of Anesthesiology, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi, 330006, China.
| | - Peng Yu
- Jiujiang Clinical Precision Medicine Research Center, Jiujiang, Jiangxi, 332000, China; Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Jiangxi Medical College, Nanchang University, No. 1, Minde Road, Donghu District, Nanchang 330006, China; Institute for the Study of Endocrinology and Metabolism in Jiangxi Province, Nanchang 330006, China.
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5
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Alhabsi A, Butt H, Kirschner GK, Blilou I, Mahfouz MM. SCR106 splicing factor modulates abiotic stress responses by maintaining RNA splicing in rice. JOURNAL OF EXPERIMENTAL BOTANY 2024; 75:802-818. [PMID: 37924151 PMCID: PMC10837019 DOI: 10.1093/jxb/erad433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 10/29/2023] [Indexed: 11/06/2023]
Abstract
Plants employ sophisticated molecular machinery to fine-tune their responses to growth, developmental, and stress cues. Gene expression influences plant cellular responses through regulatory processes such as transcription and splicing. Pre-mRNA is alternatively spliced to increase the genome coding potential and further regulate expression. Serine/arginine-rich (SR) proteins, a family of pre-mRNA splicing factors, recognize splicing cis-elements and regulate both constitutive and alternative splicing. Several studies have reported SR protein genes in the rice genome, subdivided into six subfamilies based on their domain structures. Here, we identified a new splicing factor in rice with an RNA recognition motif (RRM) and SR-dipeptides, which is related to the SR proteins, subfamily SC. OsSCR106 regulates pre-mRNA splicing under abiotic stress conditions. It localizes to the nuclear speckles, a major site for pre-mRNA splicing in the cell. The loss-of-function scr106 mutant is hypersensitive to salt, abscisic acid, and low-temperature stress, and harbors a developmental abnormality indicated by the shorter length of the shoot and root. The hypersensitivity to stress phenotype was rescued by complementation using OsSCR106 fused behind its endogenous promoter. Global gene expression and genome-wide splicing analysis in wild-type and scr106 seedlings revealed that OsSCR106 regulates its targets, presumably through regulating the alternative 3'-splice site. Under salt stress conditions, we identified multiple splice isoforms regulated by OsSCR106. Collectively, our results suggest that OsSCR106 is an important splicing factor that plays a crucial role in accurate pre-mRNA splicing and regulates abiotic stress responses in plants.
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Affiliation(s)
- Abdulrahman Alhabsi
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Haroon Butt
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Gwendolyn K Kirschner
- Laboratory of Plant Cell and Developmental Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Ikram Blilou
- Laboratory of Plant Cell and Developmental Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Magdy M Mahfouz
- Laboratory for Genome Engineering and Synthetic Biology, Division of Biological Sciences, 4700 King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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Guo L, Liu JJ, Long SY, Wang PY, Li S, Wang JL, Wei XF, Li J, Lei L, Huang AL, Hu JL. TIM22 and TIM29 inhibit HBV replication by up-regulating SRSF1 expression. J Med Virol 2024; 96:e29439. [PMID: 38294104 DOI: 10.1002/jmv.29439] [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: 09/13/2023] [Revised: 01/10/2024] [Accepted: 01/19/2024] [Indexed: 02/01/2024]
Abstract
Hepatitis B virus (HBV) infection is a serious global health problem. After the viruses infect the human body, the host can respond to the virus infection by coordinating various cellular responses, in which mitochondria play an important role. Evidence has shown that mitochondrial proteins are involved in host antiviral responses. In this study, we found that the overexpression of TIM22 and TIM29, the members of the inner membrane translocase TIM22 complex, significantly reduced the level of intracellular HBV DNA and RNA and secreted HBV surface antigens and E antigen. The effects of TIM22 and TIM29 on HBV replication and transcription is attributed to the reduction of core promoter activity mediated by the increased expression of SRSF1 which acts as a suppressor of HBV replication. This study provides new evidence for the critical role of mitochondria in the resistance of HBV infection and new targets for the development of treatment against HBV infection.
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Affiliation(s)
- Lin Guo
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
- Department of Clinical Laboratory, Chengdu Seventh People's Hospital (Affiliated Cancer Hospital of Chengdu Medical College), Chengdu, China
| | - Jia-Jun Liu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Shao-Yuan Long
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Pei-Yun Wang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Shan Li
- Department of Clinical Laboratory, the Sixth Hospital of Chengdu, Chengdu, China
| | - Jin-Lan Wang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Xia-Fei Wei
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Southern University of Science and Technology, Shenzhen, China
| | - Jie Li
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Ling Lei
- Chongqing Health Center for Women and Children, Women and Children's Hospital of Chongqing Medical University, Chongqing, China
| | - Ai-Long Huang
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
| | - Jie-Li Hu
- Key Laboratory of Molecular Biology on Infectious Diseases, Ministry of Education, Chongqing Medical University, Chongqing, China
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Frolova EI, Palchevska O, Dominguez F, Frolov I. Alphavirus-induced transcriptional and translational shutoffs play major roles in blocking the formation of stress granules. J Virol 2023; 97:e0097923. [PMID: 37902397 PMCID: PMC10688339 DOI: 10.1128/jvi.00979-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 10/01/2023] [Indexed: 10/31/2023] Open
Abstract
IMPORTANCE Our study highlights the mechanisms behind the cell's resistance to stress granule (SG) formation after infection with Old World alphaviruses. Shortly after infection, the replication of these viruses hinders the cell's ability to form SGs, even when exposed to chemical inducers such as sodium arsenite. This resistance is primarily attributed to virus-induced transcriptional and translational shutoffs, rather than interactions between the viral nsP3 and the key components of SGs, G3BP1/2, or the ADP-ribosylhydrolase activity of nsP3 macro domain. While interactions between G3BPs and nsP3 are essential for the formation of viral replication complexes, their role in regulating SG development appears to be small, if any. Cells harboring replicating viruses or replicons with lower abilities to inhibit transcription and/or translation, but expressing wild-type nsP3, retain the ability for SG development. Understanding these mechanisms of regulation of SG formation contributes to our knowledge of viral replication and the intricate relationships between alphaviruses and host cells.
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Affiliation(s)
- Elena I. Frolova
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Oksana Palchevska
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Francisco Dominguez
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ilya Frolov
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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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: 8] [Impact Index Per Article: 8.0] [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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Palchevska O, Dominguez F, Frolova EI, Frolov I. Alphavirus-induced transcriptional and translational shutoffs play major roles in blocking the formation of stress granules. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.05.547824. [PMID: 37461699 PMCID: PMC10349968 DOI: 10.1101/2023.07.05.547824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/23/2023]
Abstract
Alphavirus infections cause multiple alterations in the intracellular environment that can have both positive and negative effects on viral replication. The Old World alphaviruses, such as Sindbis (SINV), chikungunya (CHIKV), and Semliki Forest viruses, hinder the ability of vertebrate cells to form stress granules (SGs). Previously, this inhibitory function was attributed to the hypervariable domain (HVD) of nsP3, which sequesters the key components of SGs, G3BP1 and G3BP2, and to the nsP3 macro domain. The macro domain possesses ADP-ribosylhydrolase activity, which can diminish the ADP-ribosylation of G3BP1 during viral replication. However, our recent findings do not support the prevailing notions. We demonstrate that the interactions between SINV- or CHIKV-specific nsP3s and G3BPs, and the ADP-ribosylhydrolase activity are not major contributors to the inhibitory process, at least when nsP3 is expressed at biologically relevant levels. Instead, the primary factors responsible for suppressing SG formation are virus-induced transcriptional and translational shutoffs that rapidly develop within the first few hours post infection. Poorly replicating SINV variants carrying mutated nsP3 HVD still inhibit SG development even in the presence of NaAs. Conversely, SINV mutants lacking transcription and/or translation inhibitory functions lose their ability to inhibit SGs, despite expressing high levels of wt nsP3. Moreover, we found that stable cell lines expressing GFP-nsP3 fusions retain the capacity to form SGs when exposed to sodium arsenite. However, our results do not rule out a possibility that additional virus-induced changes in cell biology may contribute to the suppression of SG formation.
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Affiliation(s)
- Oksana Palchevska
- Department of Microbiology, University of Alabama at Birmingham, AL, USA
| | | | - Elena I. Frolova
- Department of Microbiology, University of Alabama at Birmingham, AL, USA
| | - Ilya Frolov
- Department of Microbiology, University of Alabama at Birmingham, AL, USA
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Chang J, Yan S, Geng Z, Wang Z. Inhibition of splicing factors SF3A3 and SRSF5 contributes to As 3+/Se 4+ combination-mediated proliferation suppression and apoptosis induction in acute promyelocytic leukemia cells. Arch Biochem Biophys 2023; 743:109677. [PMID: 37356608 DOI: 10.1016/j.abb.2023.109677] [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: 04/17/2023] [Revised: 05/28/2023] [Accepted: 06/22/2023] [Indexed: 06/27/2023]
Abstract
The low-dose combination of Arsenite (As3+) and selenite (Se4+) has the advantages of lower biological toxicity and better curative effects for acute promyelocytic leukemia (APL) therapy. However, the underlying mechanisms remain unclear. Here, based on the fact that the combination of 2 μM A3+ plus 4 μM Se4+ possessed a stronger anti-leukemic effect on APL cell line NB4 as compared with each individual, we employed iTRAQ-based quantitative proteomics to identify a total of 58 proteins that were differentially expressed after treatment with As3+/Se4+ combination rather than As3+ or Se4+ alone, the majority of which were involved in spliceosome pathway. Among them, eight proteins stood out by virtue of their splicing function and significant changes. They were validated as being decreased in mRNA and protein levels under As3+/Se4+ combination treatment. Further functional studies showed that only knockdown of two splicing factors, SF3A3 and SRSF5, suppressed the growth of NB4 cells. The reduction of SF3A3 was found to cause G1/S cell cycle arrest, which resulted in proliferation inhibition. Moreover, SRSF5 downregulation induced cell apoptosis through the activation of caspase-3. Taken together, these findings indicate that SF3A3 and SRSF5 function as pro-leukemic factors and can be potential novel therapeutic targets for APL.
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Affiliation(s)
- Jiayin Chang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, PR China
| | - Shihai Yan
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, PR China
| | - Zhirong Geng
- College of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, 210046, PR China.
| | - Zhilin Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing, 210023, PR China.
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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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12
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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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13
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Kumar K, Sinha SK, Maity U, Kirti PB, Kumar KRR. Insights into established and emerging roles of SR protein family in plants and animals. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1763. [PMID: 36131558 DOI: 10.1002/wrna.1763] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/11/2022] [Accepted: 08/22/2022] [Indexed: 05/13/2023]
Abstract
Splicing of pre-mRNA is an essential part of eukaryotic gene expression. Serine-/arginine-rich (SR) proteins are highly conserved RNA-binding proteins present in all metazoans and plants. SR proteins are involved in constitutive and alternative splicing, thereby regulating the transcriptome and proteome diversity in the organism. In addition to their role in splicing, SR proteins are also involved in mRNA export, nonsense-mediated mRNA decay, mRNA stability, and translation. Due to their pivotal roles in mRNA metabolism, SR proteins play essential roles in normal growth and development. Hence, any misregulation of this set of proteins causes developmental defects in both plants and animals. SR proteins from the animal kingdom are extensively studied for their canonical and noncanonical functions. Compared with the animal kingdom, plant genomes harbor more SR protein-encoding genes and greater diversity of SR proteins, which are probably evolved for plant-specific functions. Evidence from both plants and animals confirms the essential role of SR proteins as regulators of gene expression influencing cellular processes, developmental stages, and disease conditions. This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing.
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Affiliation(s)
- Kundan Kumar
- Department of Biotechnology, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
| | - Shubham Kumar Sinha
- Department of Biotechnology, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
| | - Upasana Maity
- Department of Biotechnology, Indira Gandhi National Tribal University (IGNTU), Amarkantak, India
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14
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Kim GN, Yu KL, Kim HI, You JC. Investigation of the effect of SRSF9 overexpression on HIV-1 production. BMB Rep 2022; 55:639-644. [PMID: 36330710 PMCID: PMC9813430] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Indexed: 12/29/2022] Open
Abstract
Serine-arginine-rich splicing factors (SRSFs) are members of RNA processing proteins in the serine-arginine-rich (SR) family that could regulate the alternative splicing of the human immunodeficiency virus-1 (HIV-1). Whether SRSF9 has any effect on HIV-1 regulation requires elucidation. Here, we report for the first time the effects and mechanisms of SRSF9 on HIV-1 regulation. The overexpression of SRSF9 inhibits viral production and infectivity in both HEK293T and MT-4 cells. Deletion analysis of SRSF9 determined that the RNA regulation motif domain of SRSF9 is important for anti-HIV-1 effects. Furthermore, overexpression of SRSF9 increases multiple spliced forms of viral mRNA, such as Vpr mRNA. These data suggest that SRSF9 overexpression inhibits HIV-1 production by inducing the imbalanced HIV-1 mRNA splicing that could be exploited further for a novel HIV-1 therapeutic molecule. [BMB Reports 2022; 55(12): 639-644].
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Affiliation(s)
- Ga-Na Kim
- Department of Pathology, National Research Laboratory for Molecular Virology, College of Medicine, The Catholic University of Korea, Seoul 05505, Korea
| | - Kyung-Lee Yu
- Department of Pathology, National Research Laboratory for Molecular Virology, College of Medicine, The Catholic University of Korea, Seoul 05505, Korea
| | - Hae-In Kim
- Department of Pathology, National Research Laboratory for Molecular Virology, College of Medicine, The Catholic University of Korea, Seoul 05505, Korea
| | - Ji Chang You
- Department of Pathology, National Research Laboratory for Molecular Virology, College of Medicine, The Catholic University of Korea, Seoul 05505, Korea,Corresponding author. Tel: +82-2-3147-8734; Fax: +82-2-3147-9282; E-mail:
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15
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Splicing factor SRSF3 represses translation of p21 cip1/waf1 mRNA. Cell Death Dis 2022; 13:933. [PMID: 36344491 PMCID: PMC9640673 DOI: 10.1038/s41419-022-05371-x] [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: 06/15/2022] [Revised: 10/18/2022] [Accepted: 10/24/2022] [Indexed: 11/09/2022]
Abstract
Serine/arginine-rich splicing factor 3 (SRSF3) is an RNA binding protein that most often regulates gene expression at the splicing level. Although the role of SRSF3 in mRNA splicing in the nucleus is well known, its splicing-independent role outside of the nucleus is poorly understood. Here, we found that SRSF3 exerts a translational control of p21 mRNA. Depletion of SRSF3 induces cellular senescence and increases the expression of p21 independent of p53. Consistent with the expression patterns of SRSF3 and p21 mRNA in the TCGA database, SRSF3 knockdown increases the p21 mRNA level and its translation efficiency as well. SRSF3 physically associates with the 3'UTR region of p21 mRNA and the translational initiation factor, eIF4A1. Our study proposes a model in which SRSF3 regulates translation by interacting with eIF4A1 at the 3'UTR region of p21 mRNA. We also found that SRSF3 localizes to the cytoplasmic RNA granule along with eIF4A1, which may assist in translational repression therein. Thus, our results provide a new mode of regulation for p21 expression, a crucial regulator of the cell cycle and senescence, which occurs at the translational level and involves SRSF3.
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16
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Burke JM, Ripin N, Ferretti MB, St Clair LA, Worden-Sapper ER, Salgado F, Sawyer SL, Perera R, Lynch KW, Parker R. RNase L activation in the cytoplasm induces aberrant processing of mRNAs in the nucleus. PLoS Pathog 2022; 18:e1010930. [PMID: 36318584 PMCID: PMC9651596 DOI: 10.1371/journal.ppat.1010930] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/11/2022] [Accepted: 10/17/2022] [Indexed: 11/13/2022] Open
Abstract
The antiviral endoribonuclease, RNase L, is activated by the mammalian innate immune response to destroy host and viral RNA to ultimately reduce viral gene expression. Herein, we show that RNase L and RNase L-mediated mRNA decay are primarily localized to the cytoplasm. Consequently, RNA-binding proteins (RBPs) translocate from the cytoplasm to the nucleus upon RNase L activation due to the presence of intact nuclear RNA. The re-localization of RBPs to the nucleus coincides with global alterations to RNA processing in the nucleus. While affecting many host mRNAs, these alterations are pronounced in mRNAs encoding type I and type III interferons and correlate with their retention in the nucleus and reduction in interferon protein production. Similar RNA processing defects also occur during infection with either dengue virus or SARS-CoV-2 when RNase L is activated. These findings reveal that the distribution of RBPs between the nucleus and cytosol is dictated by the availability of RNA in each compartment. Thus, viral infections that trigger RNase L-mediated cytoplasmic RNA in the cytoplasm also alter RNA processing in the nucleus, resulting in an ingenious multi-step immune block to protein biogenesis.
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Affiliation(s)
- James M. Burke
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States of America
- Department of Molecular Medicine, University of Florida Scripps Biomedical Research, Jupiter, Florida, United States of America
| | - Nina Ripin
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States of America
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Max B. Ferretti
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Laura A. St Clair
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Center for Metabolism of Infectious Diseases, Colorado State University, Fort Collins, Colorado, United States of America
| | - Emma R. Worden-Sapper
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Fernando Salgado
- Department of Molecular Medicine, University of Florida Scripps Biomedical Research, Jupiter, Florida, United States of America
| | - Sara L. Sawyer
- Department of Molecular, Cellular and Developmental Biology, University of Colorado Boulder, Boulder, Colorado, United States of America
| | - Rushika Perera
- Center for Vector-Borne Infectious Diseases, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Center for Metabolism of Infectious Diseases, Colorado State University, Fort Collins, Colorado, United States of America
| | - Kristen W. Lynch
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Roy Parker
- Department of Biochemistry, University of Colorado Boulder, Boulder, Colorado, United States of America
- Howard Hughes Medical Institute, University of Colorado Boulder, Boulder, Colorado, United States of America
- BioFrontiers Institute, University of Colorado Boulder, Boulder, Colorado, United States of America
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17
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Urbanski L, Brugiolo M, Park S, Angarola BL, Leclair NK, Yurieva M, Palmer P, Sahu SK, Anczuków O. MYC regulates a pan-cancer network of co-expressed oncogenic splicing factors. Cell Rep 2022; 41:111704. [DOI: 10.1016/j.celrep.2022.111704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 05/16/2022] [Accepted: 11/01/2022] [Indexed: 11/23/2022] Open
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18
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Wan L, Deng M, Zhang H. SR Splicing Factors Promote Cancer via Multiple Regulatory Mechanisms. Genes (Basel) 2022; 13:1659. [PMID: 36140826 PMCID: PMC9498594 DOI: 10.3390/genes13091659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/09/2022] [Accepted: 09/14/2022] [Indexed: 11/17/2022] Open
Abstract
Substantial emerging evidence supports that dysregulated RNA metabolism is associated with tumor initiation and development. Serine/Arginine-Rich proteins (SR) are a number of ultraconserved and structurally related proteins that contain a characteristic RS domain rich in arginine and serine residues. SR proteins perform a critical role in spliceosome assembling and conformational transformation, contributing to precise alternative RNA splicing. Moreover, SR proteins have been reported to participate in multiple other RNA-processing-related mechanisms than RNA splicing, such as genome stability, RNA export, and translation. The dysregulation of SR proteins has been reported to contribute to tumorigenesis through multiple mechanisms. Here we reviewed the different biological roles of SR proteins and strategies for functional rectification of SR proteins that may serve as potential therapeutic approaches for cancer.
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Affiliation(s)
- Ledong Wan
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy of Chinese Academy of Medical Sciences (2019RU042), Zhejiang University School of Medicine, Hangzhou 310058, China
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Min Deng
- Department of Pathology, First Peoples Hospital Fuyang, Hangzhou 311400, China
| | - Honghe Zhang
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy of Chinese Academy of Medical Sciences (2019RU042), Zhejiang University School of Medicine, Hangzhou 310058, China
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19
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Muehlbauer LK, Wei T, Shishkova E, Coon JJ, Lambert PF. IQGAP1 and RNA Splicing in the Context of Head and Neck via Phosphoproteomics. J Proteome Res 2022; 21:2211-2223. [PMID: 35980772 PMCID: PMC9833422 DOI: 10.1021/acs.jproteome.2c00309] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
IQGAP1 (IQ motif-containing GTPase-activating protein 1) scaffolds several signaling pathways in mammalian cells that are implicated in carcinogenesis, including the RAS and PI3K pathways that involve multiple protein kinases. IQGAP1 has been shown to promote head and neck squamous cell carcinoma (HNSCC); however, the underlying mechanism(s) remains unclear. Here, we report a mass spectrometry-based analysis identifying differences in phosphorylation of cellular proteins in vivo and in vitro in the presence or absence of IQGAP1. By comparing the esophageal phosphoproteome profiles between Iqgap1+/+ and Iqgap1-/- mice, we identified RNA splicing as one of the most altered cellular processes. Serine/arginine-rich splicing factor 6 (SRSF6) was the protein with the most downregulated levels of phosphorylation in Iqgap1-/- tissue. We confirmed that the absence of IQGAP1 reduced SRSF6 phosphorylation both in vivo and in vitro. We then expanded our analysis to human normal oral keratinocytes. Again, we found factors involved in RNA splicing to be highly altered in the phosphoproteome profile upon genetic disruption of IQGAP1. Both the Clinical Proteomic Tumor Analysis Consortium (CPTAC) and the Cancer Genome Atlas (TCGA) data sets indicate that phosphorylation of splicing-related proteins is important in HNSCC prognosis. The Biological General Repository for Interaction Datasets (BioGRID) repository also suggested multiple interactions between IQGAP1 and splicing-related proteins. Based on these collective observations, we propose that IQGAP1 regulates the phosphorylation of splicing proteins, which potentially affects their splicing activities and, therefore, contributes to HNSCC. Raw data are available from the MassIVE database with identifier MSV000087770.
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Affiliation(s)
- Laura K. Muehlbauer
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Tao Wei
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Evgenia Shishkova
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Joshua J. Coon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
- National Center for Quantitative Biology of Complex Systems, University of Wisconsin-Madison, Madison, WI 53706, USA
- Morgridge Institute for Research, Madison, WI 53706, USA
| | - Paul F. Lambert
- McArdle Laboratory for Cancer Research, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
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20
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Sun M, Jin Y, Zhang Y, Gregorich ZR, Ren J, Ge Y, Guo W. SR Protein Kinases Regulate the Splicing of Cardiomyopathy-Relevant Genes via Phosphorylation of the RSRSP Stretch in RBM20. Genes (Basel) 2022; 13:1526. [PMID: 36140694 PMCID: PMC9498672 DOI: 10.3390/genes13091526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 11/16/2022] Open
Abstract
(1) Background: RNA binding motif 20 (RBM20) regulates mRNA splicing specifically in muscle tissues. Missense mutations in the arginine/serine (RS) domain of RBM20 lead to abnormal gene splicing and have been linked to severe dilated cardiomyopathy (DCM) in human patients and animal models. Interestingly, many of the reported DCM-linked missense mutations in RBM20 are in a highly conserved RSRSP stretch within the RS domain. Recently, it was found that the two Ser residues within this stretch are constitutively phosphorylated, yet the identity of the kinase(s) responsible for phosphorylating these residues, as well as the function of RSRSP phosphorylation, remains unknown. (2) Methods: The ability of three known SR protein kinases (SRPK1, CLK1, and AKT2) to phosphorylate the RBM20 RSRSP stretch and regulate target gene splicing was evaluated by using both in vitro and in vivo approaches. (3) Results: We found that all three kinases phosphorylated S638 and S640 in the RSRSP stretch and regulated RBM20 target gene splicing. While SRPK1 and CLK1 were both capable of directly phosphorylating the RS domain in RBM20, whether AKT2-mediated control of the RS domain phosphorylation is direct or indirect could not be determined. (4) Conclusions: Our results indicate that SR protein kinases regulate the splicing of a cardiomyopathy-relevant gene by modulating phosphorylation of the RSRSP stretch in RBM20. These findings suggest that SR protein kinases may be potential targets for the treatment of RBM20 cardiomyopathy.
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Affiliation(s)
- Mingming Sun
- Department of Zoology and Physiology, University of Wyoming, Laramie, WY 82071, USA
| | - Yutong Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Yanghai Zhang
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Zachery R Gregorich
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Jun Ren
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital Fudan University, Shanghai 200032, China
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
- Department of Cell and Regenerative Biology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53706, USA
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Wei Guo
- Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA
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21
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Gómez-Herranz M, Faktor J, Yébenes Mayordomo M, Pilch M, Nekulova M, Hernychova L, Ball KL, Vojtesek B, Hupp TR, Kote S. Emergent Role of IFITM1/3 towards Splicing Factor (SRSF1) and Antigen-Presenting Molecule (HLA-B) in Cervical Cancer. Biomolecules 2022; 12:1090. [PMID: 36008984 PMCID: PMC9405601 DOI: 10.3390/biom12081090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 07/27/2022] [Accepted: 08/01/2022] [Indexed: 11/24/2022] Open
Abstract
The IFITM restriction factors play a role in cancer cell progression through undefined mechanisms. We investigate new protein-protein interactions for IFITM1/3 in the context of cancer that would shed some light on how IFITM1/3 attenuate the expression of targeted proteins such as HLA-B. SBP-tagged IFITM1 protein was used to identify an association of IFITM1 protein with the SRSF1 splicing factor and transporter of mRNA to the ribosome. Using in situ proximity ligation assays, we confirmed a predominant cytosolic protein-protein association for SRSF1 and IFITM1/3. Accordingly, IFITM1/3 interacted with HLA-B mRNA in response to IFNγ stimulation using RNA-protein proximity ligation assays. In addition, RT-qPCR assays in IFITM1/IFITM3 null cells and wt-SiHa cells indicated that HLA-B gene expression at the mRNA level does not account for lowered HLA-B protein synthesis in response to IFNγ. Complementary, shotgun RNA sequencing did not show major transcript differences between IFITM1/IFITM3 null cells and wt-SiHa cells. Furthermore, ribosome profiling using sucrose gradient sedimentation identified a reduction in 80S ribosomal fraction an IFITM1/IFITM3 null cells compared to wild type. It was partially reverted by IFITM1/3 complementation. Our data link IFITM1/3 proteins to HLA-B mRNA and SRSF1 and, all together, our results begin to elucidate how IFITM1/3 catalyze the synthesis of target proteins. IFITMs are widely studied for their role in inhibiting viruses, and multiple studies have associated IFITMs with cancer progression. Our study has identified new proteins associated with IFITMs which support their role in mediating protein expression; a pivotal function that is highly relevant for viral infection and cancer progression. Our results suggest that IFITM1/3 affect the expression of targeted proteins; among them, we identified HLA-B. Changes in HLA-B expression could impact the presentation and recognition of oncogenic antigens on the cell surface by cytotoxic T cells and, ultimately, limit tumor cell eradication. In addition, the role of IFITMs in mediating protein abundance is relevant, as it has the potential for regulating the expression of viral and oncogenic proteins.
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Affiliation(s)
- Maria Gómez-Herranz
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
| | - Jakub Faktor
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
- Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, 65653 Brno, Czech Republic
| | - Marcos Yébenes Mayordomo
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
| | - Magdalena Pilch
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
| | - Marta Nekulova
- Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, 65653 Brno, Czech Republic
| | - Lenka Hernychova
- Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, 65653 Brno, Czech Republic
| | - Kathryn L. Ball
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
| | - Borivoj Vojtesek
- Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, 65653 Brno, Czech Republic
| | - Ted R. Hupp
- Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
- Masaryk Memorial Cancer Institute, Research Centre for Applied Molecular Oncology, 65653 Brno, Czech Republic
| | - Sachin Kote
- International Centre for Cancer Vaccine Science, University of Gdańsk, 80-822 Gdańsk, Poland
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22
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Duan L, Zaepfel BL, Aksenova V, Dasso M, Rothstein JD, Kalab P, Hayes LR. Nuclear RNA binding regulates TDP-43 nuclear localization and passive nuclear export. Cell Rep 2022; 40:111106. [PMID: 35858577 PMCID: PMC9345261 DOI: 10.1016/j.celrep.2022.111106] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 03/26/2022] [Accepted: 06/27/2022] [Indexed: 11/27/2022] Open
Abstract
Nuclear clearance of the RNA-binding protein TDP-43 is a hallmark of neurodegeneration and an important therapeutic target. Our current understanding of TDP-43 nucleocytoplasmic transport does not fully explain its predominantly nuclear localization or mislocalization in disease. Here, we show that TDP-43 exits nuclei by passive diffusion, independent of facilitated mRNA export. RNA polymerase II blockade and RNase treatment induce TDP-43 nuclear efflux, suggesting that nuclear RNAs sequester TDP-43 in nuclei and limit its availability for passive export. Induction of TDP-43 nuclear efflux by short, GU-rich oligomers (presumably by outcompeting TDP-43 binding to endogenous nuclear RNAs), and nuclear retention conferred by splicing inhibition, demonstrate that nuclear TDP-43 localization depends on binding to GU-rich nuclear RNAs. Indeed, RNA-binding domain mutations markedly reduce TDP-43 nuclear localization and abolish transcription blockade-induced nuclear efflux. Thus, the nuclear abundance of GU-RNAs, dictated by the balance of transcription, pre-mRNA processing, and RNA export, regulates TDP-43 nuclear localization.
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Affiliation(s)
- Lauren Duan
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Benjamin L Zaepfel
- Biochemistry, Cellular and Molecular Biology Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Vasilisa Aksenova
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mary Dasso
- Division of Molecular and Cellular Biology, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeffrey D Rothstein
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Petr Kalab
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Lindsey R Hayes
- Brain Science Institute, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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23
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Wang XB, Yuan LH, Yan LP, Ye YB, Lu B, Xu X. UNC13B Promote Arsenic Trioxide Resistance in Chronic Lymphoid Leukemia Through Mitochondria Quality Control. Front Oncol 2022; 12:920999. [PMID: 35707364 PMCID: PMC9190243 DOI: 10.3389/fonc.2022.920999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 05/05/2022] [Indexed: 11/19/2022] Open
Abstract
In clinical practice, arsenic trioxide can be used to treat a subset of R/R CML patients, but resistance tends to reappear quickly. We designed an experiment to study arsenic trioxide resistance in K-562 cells. Previously, we identified the UNC13B gene as potentially responsible for arsenic trioxide resistance in K-562 cells via gene chip screening followed by high-content screening. We aimed to investigate the role and mechanism of the UNC13B gene in K-562 cells, an arsenic trioxide-resistant chronic myeloid leukemia cell line. In vitro lentiviral vector-mediated UNC13B siRNA transfection was performed on K-562 cells. The roles of UNC13B in cell proliferation, apoptosis and cell cycle pathways, and colony formation were analyzed by CCK-8 assay, fluorescence-activated cell sorting, and soft agar culture, respectively. Gene chip screening was used to define the possible downstream pathways of UNC13B. Western blot was performed to further validate the possible genes mediated by UNC13B for arsenic trioxide resistance in patients with chronic myeloid leukemia. UNC13B downregulation significantly inhibited growth, promoted apoptosis, decreased colony formation, reduced the duration of the G1 phase, and increased the duration of the S phase of K-562 cells. Western blot results confirmed that UNC13B may modulate the apoptosis and proliferation of arsenic trioxide-resistant chronic myeloid leukemia cells through the mediation of MAP3K7, CDK4, and PINK1. UNC13B is a potential therapeutic target for patients with arsenic trioxide-resistant chronic myeloid leukemia.
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Affiliation(s)
- Xiao-Bo Wang
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Li-Hua Yuan
- Department of Pediatric Surgery, University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Le-Ping Yan
- Scientific Research Center, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Yong-Bin Ye
- Department of Hematology, Zhongshan Hospital Affiliated to Sun Yat-Sen University, Zhongshan, China
| | - Bo Lu
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
| | - Xiaojun Xu
- Department of Hematology, The Seventh Affiliated Hospital, Sun Yat-Sen University, Shenzhen, China
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You GR, Chang JT, Li HF, Cheng AJ. Multifaceted and Intricate Oncogenic Mechanisms of NDRG1 in Head and Neck Cancer Depend on Its C-Terminal 3R-Motif. Cells 2022; 11:cells11091581. [PMID: 35563887 PMCID: PMC9104279 DOI: 10.3390/cells11091581] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/04/2022] [Accepted: 05/05/2022] [Indexed: 12/12/2022] Open
Abstract
N-Myc downstream-regulated 1 (NDRG1) has inconsistent oncogenic functions in various cancers. We surveyed and characterized the role of NDRG1 in head and neck cancer (HNC). Cellular methods included spheroid cell formation, clonogenic survival, cell viability, and Matrigel invasion assays. Molecular techniques included transcriptomic profiling, RT-qPCR, immunoblotting, in vitro phosphorylation, immunofluorescent staining, and confocal microscopy. Prognostic significance was assessed by Kaplan–Meier analysis. NDRG1 participated in diverse oncogenic functions in HNC cells, mainly stress response and cell motility. Notably, NDRG1 contributed to spheroid cell growth, radio-chemoresistance, and upregulation of stemness-related markers (CD44 and Twist1). NDRG1 facilitated cell migration and invasion, and was associated with modulation of the extracellular matrix molecules (fibronectin, vimentin). Characterizing the 3R-motif in NDRG1 revealed its mechanism in the differential regulation of the phenotypes. The 3R-motif displayed minimal effect on cancer stemness but was crucial for cell motility. Phosphorylating the motif by GSK3b at serine residues led to its nuclear translocation to promote motility. Clinical analyses supported the oncogenic function of NDRG1, which was overexpressed in HNC and associated with poor prognosis. The data elucidate the multifaceted and intricate mechanisms of NDRG1 in HNC. NDRG1 may be a prognostic indicator or therapeutic target for refractory HNC.
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Affiliation(s)
- Guo-Rung You
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
| | - Joseph T. Chang
- Department of Radiation Oncology and Proton Therapy Center, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan 33302, Taiwan;
- School of Medicine, Chang Gung University, Taoyuan 33302, Taiwan
| | - Hsiao-Fan Li
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
| | - Ann-Joy Cheng
- Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
- Department of Radiation Oncology and Proton Therapy Center, Linkou Chang Gung Memorial Hospital and Chang Gung University, Taoyuan 33302, Taiwan;
- Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan 33302, Taiwan;
- Correspondence: ; Tel.: +886-3-211-8800
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25
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Abstract
Cell fusions have a long history of supporting biomedical research. These experimental models, historically referred to as 'somatic cell hybrids', involve combining the plasma membranes of two cells and merging their nuclei within a single cytoplasm. Cell fusion studies involving human and chimpanzee pluripotent stem cells, rather than somatic cells, highlight the need for responsible communication and a revised nomenclature. Applying the terms 'hybrid' and 'parental' to the fused and source cell lines, respectively, evokes reproductive relationships that do not exist between humans and other species. These misnomers become more salient in the context of fused pluripotent stem cells derived from different but closely related species. Here, we propose a precise, versatile and generalizable framework to describe these fused cell lines. We recommend the term 'composite cell line', to distinguish cell lines that are experimentally created through fusions from both reproductive hybrids and natural cell fusion events without obscuring the model in overly technical terms. For scientific audiences, we further recommend technical nomenclature that describes the contributing species, ploidy and cell type.
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26
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Zhang Y, Wang C, Sun M, Jin Y, Braz CU, Khatib H, Hacker TA, Liss M, Gotthardt M, Granzier H, Ge Y, Guo W. RBM20 phosphorylation and its role in nucleocytoplasmic transport and cardiac pathogenesis. FASEB J 2022; 36:e22302. [PMID: 35394688 PMCID: PMC9233413 DOI: 10.1096/fj.202101811rr] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2021] [Revised: 03/21/2022] [Accepted: 03/24/2022] [Indexed: 12/13/2022]
Abstract
Arginine-serine (RS) domain(s) in splicing factors are critical for protein-protein interaction in pre-mRNA splicing. Phosphorylation of RS domain is important for splicing control and nucleocytoplasmic transport in the cell. RNA-binding motif 20 (RBM20) is a splicing factor primarily expressed in the heart. A previous study using phospho-antibody against RS domain showed that RS domain can be phosphorylated. However, its actual phosphorylation sites and function have not been characterized. Using middle-down mass spectrometry, we identified 16 phosphorylation sites, two of which (S638 and S640 in rats, or S637 and S639 in mice) were located in the RSRSP stretch in the RS domain. Mutations on S638 and S640 regulated splicing, promoted nucleocytoplasmic transport and protein-RNA condensates. Phosphomimetic mutations on S638 and S640 indicated that phosphorylation was not the major cause for RBM20 nucleocytoplasmic transport and condensation in vitro. We generated a S637A knock-in (KI) mouse model (Rbm20S637A ) and observed the reduced RBM20 phosphorylation. The KI mice exhibited aberrant gene splicing, protein condensates, and a dilated cardiomyopathy (DCM)-like phenotype. Transcriptomic profiling demonstrated that KI mice had altered expression and splicing of genes involving cardiac dysfunction, protein localization, and condensation. Our in vitro data showed that phosphorylation was not a direct cause for nucleocytoplasmic transport and protein condensation. Subsequently, the in vivo results reveal that RBM20 mutations led to cardiac pathogenesis. However, the role of phosphorylation in vivo needs further investigation.
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Affiliation(s)
- Yanghai Zhang
- Department of Animal and Dairy SciencesUniversity of Wisconsin‐MadisonWisconsinUSA
| | - Chunyan Wang
- Department of Animal and Dairy SciencesUniversity of Wisconsin‐MadisonWisconsinUSA
| | - Mingming Sun
- Department of Animal ScienceUniversity of WyomingLaramieWyomingUSA
| | - Yutong Jin
- Department of ChemistryUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Camila Urbano Braz
- Department of Animal and Dairy SciencesUniversity of Wisconsin‐MadisonWisconsinUSA
| | - Hasan Khatib
- Department of Animal and Dairy SciencesUniversity of Wisconsin‐MadisonWisconsinUSA
| | - Timothy A. Hacker
- Division of Cardiovascular MedicineDepartment of MedicineUniversity of Wisconsin School of Medicine and Public HealthMadisonWisconsinUSA
| | - Martin Liss
- Neuromuscular and Cardiovascular Cell BiologyMax Delbrueck Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
| | - Michael Gotthardt
- Neuromuscular and Cardiovascular Cell BiologyMax Delbrueck Center for Molecular Medicine in the Helmholtz AssociationBerlinGermany
- Charité UniversitätsmedizinBerlinGermany
| | - Henk Granzier
- Department of Cellular and Molecular MedicineUniversity of ArizonaTucsonArizonaUSA
| | - Ying Ge
- Department of ChemistryUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
- Department of Cell and Regenerative BiologySchool of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
- Human Proteomics ProgramSchool of Medicine and Public HealthUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Wei Guo
- Department of Animal and Dairy SciencesUniversity of Wisconsin‐MadisonWisconsinUSA
- Department of Animal ScienceUniversity of WyomingLaramieWyomingUSA
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27
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Lu YY, Krebber H. Nuclear mRNA Quality Control and Cytoplasmic NMD Are Linked by the Guard Proteins Gbp2 and Hrb1. Int J Mol Sci 2021; 22:ijms222011275. [PMID: 34681934 PMCID: PMC8541090 DOI: 10.3390/ijms222011275] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/13/2021] [Accepted: 10/17/2021] [Indexed: 12/23/2022] Open
Abstract
Pre-mRNA splicing is critical for cells, as defects in this process can lead to altered open reading frames and defective proteins, potentially causing neurodegenerative diseases and cancer. Introns are removed in the nucleus and splicing is documented by the addition of exon-junction-complexes (EJCs) at exon-exon boundaries. This “memory” of splicing events is important for the ribosome, which translates the RNAs in the cytoplasm. In case a stop codon was detected before an EJC, translation is blocked and the RNA is eliminated by the nonsense-mediated decay (NMD). In the model organism Saccharomyces cerevisiae, two guard proteins, Gbp2 and Hrb1, have been identified as nuclear quality control factors for splicing. In their absence, intron-containing mRNAs leak into the cytoplasm. Their presence retains transcripts until the process is completed and they release the mRNAs by recruitment of the export factor Mex67. On transcripts that experience splicing problems, these guard proteins recruit the nuclear RNA degradation machinery. Interestingly, they continue their quality control function on exported transcripts. They support NMD by inhibiting translation and recruiting the cytoplasmic degradation factors. In this way, they link the nuclear and cytoplasmic quality control systems. These discoveries are also intriguing for humans, as homologues of these guard proteins are present also in multicellular organisms. Here, we provide an overview of the quality control mechanisms of pre-mRNA splicing, and present Gbp2 and Hrb1, as well as their human counterparts, as important players in these pathways.
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28
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Haward F, Maslon MM, Yeyati PL, Bellora N, Hansen JN, Aitken S, Lawson J, von Kriegsheim A, Wachten D, Mill P, Adams IR, Caceres JF. Nucleo-cytoplasmic shuttling of splicing factor SRSF1 is required for development and cilia function. eLife 2021; 10:e65104. [PMID: 34338635 PMCID: PMC8352595 DOI: 10.7554/elife.65104] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 07/30/2021] [Indexed: 12/02/2022] Open
Abstract
Shuttling RNA-binding proteins coordinate nuclear and cytoplasmic steps of gene expression. The SR family proteins regulate RNA splicing in the nucleus and a subset of them, including SRSF1, shuttles between the nucleus and cytoplasm affecting post-splicing processes. However, the physiological significance of this remains unclear. Here, we used genome editing to knock-in a nuclear retention signal (NRS) in Srsf1 to create a mouse model harboring an SRSF1 protein that is retained exclusively in the nucleus. Srsf1NRS/NRS mutants displayed small body size, hydrocephalus, and immotile sperm, all traits associated with ciliary defects. We observed reduced translation of a subset of mRNAs and decreased abundance of proteins involved in multiciliogenesis, with disruption of ciliary ultrastructure and motility in cells and tissues derived from this mouse model. These results demonstrate that SRSF1 shuttling is used to reprogram gene expression networks in the context of high cellular demands, as observed here, during motile ciliogenesis.
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Affiliation(s)
- Fiona Haward
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Magdalena M Maslon
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Patricia L Yeyati
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Nicolas Bellora
- Institute of Nuclear Technologies for Health (Intecnus), National Scientific and Technical Research Council (CONICET)BarilocheArgentina
| | - Jan N Hansen
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Stuart Aitken
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Jennifer Lawson
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Alex von Kriegsheim
- Edinburgh Cancer Research United Kingdom Centre, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Dagmar Wachten
- Institute of Innate Immunity, Biophysical Imaging, Medical Faculty, University of BonnBonnGermany
| | - Pleasantine Mill
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Ian R Adams
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
| | - Javier F Caceres
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of EdinburghEdinburghUnited Kingdom
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29
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Biology of the mRNA Splicing Machinery and Its Dysregulation in Cancer Providing Therapeutic Opportunities. Int J Mol Sci 2021; 22:ijms22105110. [PMID: 34065983 PMCID: PMC8150589 DOI: 10.3390/ijms22105110] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 05/07/2021] [Accepted: 05/07/2021] [Indexed: 12/13/2022] Open
Abstract
Dysregulation of messenger RNA (mRNA) processing—in particular mRNA splicing—is a hallmark of cancer. Compared to normal cells, cancer cells frequently present aberrant mRNA splicing, which promotes cancer progression and treatment resistance. This hallmark provides opportunities for developing new targeted cancer treatments. Splicing of precursor mRNA into mature mRNA is executed by a dynamic complex of proteins and small RNAs called the spliceosome. Spliceosomes are part of the supraspliceosome, a macromolecular structure where all co-transcriptional mRNA processing activities in the cell nucleus are coordinated. Here we review the biology of the mRNA splicing machinery in the context of other mRNA processing activities in the supraspliceosome and present current knowledge of its dysregulation in lung cancer. In addition, we review investigations to discover therapeutic targets in the spliceosome and give an overview of inhibitors and modulators of the mRNA splicing process identified so far. Together, this provides insight into the value of targeting the spliceosome as a possible new treatment for lung cancer.
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30
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Wagner RE, Frye M. Noncanonical functions of the serine-arginine-rich splicing factor (SR) family of proteins in development and disease. Bioessays 2021; 43:e2000242. [PMID: 33554347 DOI: 10.1002/bies.202000242] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 12/19/2022]
Abstract
Members of the serine/arginine (SR)-rich protein family of splicing factors play versatile roles in RNA processing steps and are often essential for normal development. Dynamic changes in RNA processing and turnover allow fast cellular adaptions to a changing microenvironment and thereby closely cooperate with transcription factor networks that establish cell identity within tissues. SR proteins play fundamental roles in the processing of pre-mRNAs by regulating constitutive and alternative splicing. More recently, SR proteins have also been implicated in other aspects of RNA metabolism such as mRNA stability, transport and translation. The- emerging noncanonical functions highlight the multifaceted functions of these SR proteins and identify them as important coordinators of gene expression programmes. Accordingly, most SR proteins are essential for normal cell function and their misregulation contributes to human diseases such as cancer.
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Affiliation(s)
- Rebecca E Wagner
- German Cancer Research Center - Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
| | - Michaela Frye
- German Cancer Research Center - Deutsches Krebsforschungszentrum (DKFZ), Heidelberg, Germany
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31
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Costa R, Rodia MT, Zini N, Pegoraro V, Marozzo R, Capanni C, Angelini C, Lattanzi G, Santi S, Cenacchi G. Morphological study of TNPO3 and SRSF1 interaction during myogenesis by combining confocal, structured illumination and electron microscopy analysis. Mol Cell Biochem 2021; 476:1797-1811. [PMID: 33452620 PMCID: PMC7940345 DOI: 10.1007/s11010-020-04023-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Transportin3 (TNPO3) shuttles the SR proteins from the cytoplasm to the nucleus. The SR family includes essential splicing factors, such as SRSF1, that influence alternative splicing, controlling protein diversity in muscle and satellite cell differentiation. Given the importance of alternative splicing in the myogenic process and in the maintenance of healthy muscle, alterations in the splicing mechanism might contribute to the development of muscle disorders. Combining confocal, structured illumination and electron microscopy, we investigated the expression of TNPO3 and SRSF1 during myogenesis, looking at nuclear and cytoplasmic compartments. We investigated TNPO3 and its interaction with SRSF1 and we observed that SRSF1 remained mainly localized in the nucleus, while TNPO3 decreased in the cytoplasm and was strongly clustered in the nuclei of differentiated myotubes. In conclusion, combining different imaging techniques led us to describe the behavior of TNPO3 and SRSF1 during myogenesis, showing that their dynamics follow the myogenic process and could influence the proteomic network necessary during myogenesis. The combination of different high-, super- and ultra-resolution imaging techniques led us to describe the behavior of TNPO3 and its interaction with SRSF1, looking at nuclear and cytoplasmic compartments. These observations represent a first step in understanding the role of TNPO3 and SRFSF1 in complex mechanisms, such as myogenesis.
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Affiliation(s)
- Roberta Costa
- Department of Biomedical and Neuromotor Sciences-DIBINEM, Alma Mater Studiorum University of Bologna, via Massarenti 9, 40138, Bologna, Italy.,Center of Applied Biomedical Research-CRBA, Alma Mater Studiorum University of Bologna, St. Orsola Hospital, via Massarenti 9, 40138, Bologna, Italy
| | - Maria Teresa Rodia
- Department of Biomedical and Neuromotor Sciences-DIBINEM, Alma Mater Studiorum University of Bologna, via Massarenti 9, 40138, Bologna, Italy.,Center of Applied Biomedical Research-CRBA, Alma Mater Studiorum University of Bologna, St. Orsola Hospital, via Massarenti 9, 40138, Bologna, Italy
| | - Nicoletta Zini
- CNR-National Research Council of Italy, Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, via di Barbiano 1/10, 40136, Bologna, Italy.,IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136, Bologna, Italy
| | - Valentina Pegoraro
- Neuromuscular Unit, Neurobiology Research group, IRCCS San Camillo Hospital, via Alberoni 70, 30126, Venice, Italy
| | - Roberta Marozzo
- Neuromuscular Unit, Neurobiology Research group, IRCCS San Camillo Hospital, via Alberoni 70, 30126, Venice, Italy
| | - Cristina Capanni
- CNR-National Research Council of Italy, Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, via di Barbiano 1/10, 40136, Bologna, Italy.,IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136, Bologna, Italy
| | - Corrado Angelini
- Neuromuscular Unit, Neurobiology Research group, IRCCS San Camillo Hospital, via Alberoni 70, 30126, Venice, Italy
| | - Giovanna Lattanzi
- CNR-National Research Council of Italy, Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, via di Barbiano 1/10, 40136, Bologna, Italy.,IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136, Bologna, Italy
| | - Spartaco Santi
- CNR-National Research Council of Italy, Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, via di Barbiano 1/10, 40136, Bologna, Italy.,IRCCS Istituto Ortopedico Rizzoli, via di Barbiano 1/10, 40136, Bologna, Italy
| | - Giovanna Cenacchi
- Department of Biomedical and Neuromotor Sciences-DIBINEM, Alma Mater Studiorum University of Bologna, via Massarenti 9, 40138, Bologna, Italy. .,Center of Applied Biomedical Research-CRBA, Alma Mater Studiorum University of Bologna, St. Orsola Hospital, via Massarenti 9, 40138, Bologna, Italy.
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32
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AMP-activated protein kinase regulates β-catenin protein synthesis by phosphorylating serine/arginine-rich splicing factor 9. Biochem Biophys Res Commun 2020; 534:347-352. [PMID: 33248688 DOI: 10.1016/j.bbrc.2020.11.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/17/2020] [Indexed: 12/13/2022]
Abstract
β-catenin is a multi-functional protein with a central role in regulating embryonic development and tissue homeostasis. The abnormal accumulation of β-catenin, due to disrupted β-catenin degradation or unregulated β-catenin synthesis, causes the development of cancer. A recent study showed that the overexpression of proto-oncogene serine/arginine-rich splicing factor 9 (SRSF9) promotes β-catenin accumulation via binding β-catenin mRNA and enhancing its translation in a manner that is dependent on the mechanistic target of rapamycin (mTOR). However, the regulation of the interaction between SRSF9 and mRNA of β-catenin remains unclear. Here, we show that AMP-activated protein kinase (AMPK) phosphorylates SRSF9 at the RNA-interacting SWQDLKD motif that plays a major role in determining substrate specificity. The phosphorylation by AMPK inhibits the binding of SRSF9 to β-catenin mRNA and suppresses β-catenin protein synthesis caused by SRSF9 overexpression without changing the β-catenin mRNA levels. Our findings suggest that AMPK activators are potential therapeutic targets for SRSF9-derived overproduction of β-catenin in cancer cells.
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33
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Guha S, Bhaumik SR. Viral regulation of mRNA export with potentials for targeted therapy. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2020; 1864:194655. [PMID: 33246183 DOI: 10.1016/j.bbagrm.2020.194655] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 10/15/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
Eukaryotic gene expression begins with transcription in the nucleus to synthesize mRNA (messenger RNA), which is subsequently exported to the cytoplasm for translation to protein. Like transcription and translation, mRNA export is an important regulatory step of eukaryotic gene expression. Various factors are involved in regulating mRNA export, and thus gene expression. Intriguingly, some of these factors interact with viral proteins, and such interactions interfere with mRNA export of the host cell, favoring viral RNA export. Hence, viruses hijack host mRNA export machinery for export of their own RNAs from nucleus to cytoplasm for translation to proteins for viral life cycle, suppressing host mRNA export (and thus host gene expression and immune/antiviral response). Therefore, the molecules that can impair the interactions of these mRNA export factors with viral proteins could emerge as antiviral therapeutic agents to suppress viral RNA transport and enhance host mRNA export, thereby promoting host gene expression and immune response. Thus, there has been a number of studies to understand how virus hijacks mRNA export machinery in suppressing host gene expression and promoting its own RNA export to the cytoplasm for translation to proteins required for viral replication/assembly/life cycle towards developing targeted antiviral therapies, as concisely described here.
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Affiliation(s)
- Shalini Guha
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA
| | - Sukesh R Bhaumik
- Department of Biochemistry and Molecular Biology, Southern Illinois University School of Medicine, Carbondale, IL 62901, USA.
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34
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Leclair NK, Brugiolo M, Urbanski L, Lawson SC, Thakar K, Yurieva M, George J, Hinson JT, Cheng A, Graveley BR, Anczuków O. Poison Exon Splicing Regulates a Coordinated Network of SR Protein Expression during Differentiation and Tumorigenesis. Mol Cell 2020; 80:648-665.e9. [PMID: 33176162 PMCID: PMC7680420 DOI: 10.1016/j.molcel.2020.10.019] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 10/07/2020] [Accepted: 10/12/2020] [Indexed: 12/18/2022]
Abstract
The RNA isoform repertoire is regulated by splicing factor (SF) expression, and alterations in SF levels are associated with disease. SFs contain ultraconserved poison exon (PE) sequences that exhibit greater identity across species than nearby coding exons, but their physiological role and molecular regulation is incompletely understood. We show that PEs in serine-arginine-rich (SR) proteins, a family of 14 essential SFs, are differentially spliced during induced pluripotent stem cell (iPSC) differentiation and in tumors versus normal tissues. We uncover an extensive cross-regulatory network of SR proteins controlling their expression via alternative splicing coupled to nonsense-mediated decay. We define sequences that regulate PE inclusion and protein expression of the oncogenic SF TRA2β using an RNA-targeting CRISPR screen. We demonstrate location dependency of RS domain activity on regulation of TRA2β-PE using CRISPR artificial SFs. Finally, we develop splice-switching antisense oligonucleotides to reverse the increased skipping of TRA2β-PE detected in breast tumors, altering breast cancer cell viability, proliferation, and migration.
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Affiliation(s)
- Nathan K Leclair
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | - Mattia Brugiolo
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Laura Urbanski
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | - Shane C Lawson
- Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA
| | - Ketan Thakar
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Marina Yurieva
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA
| | - Joshy George
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - John Travis Hinson
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA
| | - Albert Cheng
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - Brenton R Graveley
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA.
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Paz S, Ritchie A, Mauer C, Caputi M. The RNA binding protein SRSF1 is a master switch of gene expression and regulation in the immune system. Cytokine Growth Factor Rev 2020; 57:19-26. [PMID: 33160830 DOI: 10.1016/j.cytogfr.2020.10.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 12/22/2022]
Abstract
Serine/Arginine splicing factor 1 (SRSF1) is an RNA binding protein abundantly expressed in most tissues. The pleiotropic functions of SRSF1 exert multiple roles in gene expression by regulating major steps in transcription, processing, export through the nuclear pores and translation of nascent RNA transcripts. The aim of this review is to highlight recent findings in the functions of this protein and to describe its role in immune system development, functions and regulation.
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Affiliation(s)
- Sean Paz
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, United States
| | - Anastasia Ritchie
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, United States
| | - Christopher Mauer
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, United States
| | - Massimo Caputi
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd, Boca Raton, FL, 33431, United States.
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36
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Role of SARS-CoV-2 in Altering the RNA-Binding Protein and miRNA-Directed Post-Transcriptional Regulatory Networks in Humans. Int J Mol Sci 2020; 21:ijms21197090. [PMID: 32993015 PMCID: PMC7582926 DOI: 10.3390/ijms21197090] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/17/2020] [Accepted: 09/22/2020] [Indexed: 02/06/2023] Open
Abstract
The outbreak of a novel coronavirus SARS-CoV-2 responsible for the COVID-19 pandemic has caused a worldwide public health emergency. Due to the constantly evolving nature of the coronaviruses, SARS-CoV-2-mediated alterations on post-transcriptional gene regulations across human tissues remain elusive. In this study, we analyzed publicly available genomic datasets to systematically dissect the crosstalk and dysregulation of the human post-transcriptional regulatory networks governed by RNA-binding proteins (RBPs) and micro-RNAs (miRs) due to SARS-CoV-2 infection. We uncovered that 13 out of 29 SARS-CoV-2-encoded proteins directly interacted with 51 human RBPs, of which the majority of them were abundantly expressed in gonadal tissues and immune cells. We further performed a functional analysis of differentially expressed genes in mock-treated versus SARS-CoV-2-infected lung cells that revealed enrichment for the immune response, cytokine-mediated signaling, and metabolism-associated genes. This study also characterized the alternative splicing events in SARS-CoV-2-infected cells compared to the control, demonstrating that skipped exons and mutually exclusive exons were the most abundant events that potentially contributed to differential outcomes in response to the viral infection. A motif enrichment analysis on the RNA genomic sequence of SARS-CoV-2 clearly revealed the enrichment for RBPs such as SRSFs, PCBPs, ELAVs, and HNRNPs, suggesting the sponging of RBPs by the SARS-CoV-2 genome. A similar analysis to study the interactions of miRs with SARS-CoV-2 revealed functionally important miRs that were highly expressed in immune cells, suggesting that these interactions may contribute to the progression of the viral infection and modulate the host immune response across other human tissues. Given the need to understand the interactions of SARS-CoV-2 with key post-transcriptional regulators in the human genome, this study provided a systematic computational analysis to dissect the role of dysregulated post-transcriptional regulatory networks controlled by RBPs and miRs across tissue types during a SARS-CoV-2 infection.
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Srivastava R, Daulatabad SV, Srivastava M, Janga SC. Role of SARS-CoV-2 in altering the RNA binding protein and miRNA directed post-transcriptional regulatory networks in humans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020:2020.07.06.190348. [PMID: 32676599 PMCID: PMC7359521 DOI: 10.1101/2020.07.06.190348] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The outbreak of a novel coronavirus SARS-CoV-2 responsible for COVID-19 pandemic has caused worldwide public health emergency. Due to the constantly evolving nature of the coronaviruses, SARS-CoV-2 mediated alteration on post-transcriptional gene regulation across human tissues remains elusive. In this study, we analyze publicly available genomic datasets to systematically dissect the crosstalk and dysregulation of human post-transcriptional regulatory networks governed by RNA binding proteins (RBPs) and micro-RNAs (miRs), due to SARS-CoV-2 infection. We uncovered that 13 out of 29 SARS-CoV-2 encoded proteins directly interact with 51 human RBPs of which majority of them were abundantly expressed in gonadal tissues and immune cells. We further performed a functional analysis of differentially expressed genes in mock-treated versus SARS-CoV-2 infected lung cells that revealed enrichment for immune response, cytokine-mediated signaling, and metabolism associated genes. This study also characterized the alternative splicing events in SARS-CoV-2 infected cells compared to control demonstrating that skipped exons and mutually exclusive exons were the most abundant events that potentially contributed to differential outcomes in response to viral infection. Motif enrichment analysis on the RNA genomic sequence of SARS-CoV-2 clearly revealed the enrichment for RBPs such as SRSFs, PCBPs, ELAVs, and HNRNPs suggesting the sponging of RBPs by SARS-CoV-2 genome. A similar analysis to study the interactions of miRs with SARS-CoV-2 revealed functionally important miRs that were highly expressed in immune cells, suggesting that these interactions may contribute to the progression of the viral infection and modulate host immune response across other human tissues. Given the need to understand the interactions of SARS-CoV-2 with key post-transcriptional regulators in the human genome, this study provides a systematic computational analysis to dissect the role of dysregulated post-transcriptional regulatory networks controlled by RBPs and miRs, across tissues types during SARS-CoV-2 infection.
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Affiliation(s)
- Rajneesh Srivastava
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, 719 Indiana Ave Ste 319, Walker Plaza Building, Indianapolis, Indiana 46202
| | - Swapna Vidhur Daulatabad
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, 719 Indiana Ave Ste 319, Walker Plaza Building, Indianapolis, Indiana 46202
| | - Mansi Srivastava
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, 719 Indiana Ave Ste 319, Walker Plaza Building, Indianapolis, Indiana 46202
| | - Sarath Chandra Janga
- Department of Biohealth Informatics, School of Informatics and Computing, Indiana University Purdue University, 719 Indiana Ave Ste 319, Walker Plaza Building, Indianapolis, Indiana 46202
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, 5021 Health Information and Translational Sciences (HITS), 410 West 10th Street, Indianapolis, Indiana, 46202
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Medical Research and Library Building, 975 West Walnut Street, Indianapolis, Indiana, 46202
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Chen X, Huang S, Jiang M, Chen Y, XuHan X, Zhang Z, Lin Y, Lai Z. Genome-wide identification and expression analysis of the SR gene family in longan (Dimocarpus longan Lour.). PLoS One 2020; 15:e0238032. [PMID: 32841304 PMCID: PMC7447046 DOI: 10.1371/journal.pone.0238032] [Citation(s) in RCA: 4] [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: 02/11/2020] [Accepted: 08/07/2020] [Indexed: 12/05/2022] Open
Abstract
Longan (Dimocarpus longan Lour.) is an important commercial fruit tree in southern China. The embryogenesis of longan affects the quality and yield of fruit. A large number of alternative splicing events occurs during somatic embryogenesis (SE), which is regulated by serine/arginine-rich (SR) proteins. However, the functions of SR proteins in longan are poorly understood. In this study, 21 Dlo-SR gene family members belonging to six subfamilies were identified, among which Dlo-RSZ20a, Dlo-SR30, Dlo-SR17, Dlo-SR53 and Dlo-SR32 were localized in the nucleus, Dlo-RSZ20b, Dlo-RSZ20c, Dlo-RSZ20d, Dlo-SC18, Dlo-RS2Z29, Dlo-SCL41, and Dlo-SR33 were localized in chloroplasts, and Dlo-RS43, Dlo-SC33, Dlo-SC37, Dlo-RS2Z33, Dlo-RS2Z16, Dlo-RS2Z24, Dlo-SCL43, Dlo-SR112, and Dlo-SR59 were localized in the nucleus and chloroplasts. The Dlo-SR genes exhibited differential expression patterns in different tissues of longan. The transcript levels of Dlo-RSZ20a, Dlo-SC18, Dlo-RS2Z29, DLo-SR59, Dlo-SR53, and Dlo-SR17 were low in all analyzed tissues, whereas Dlo-RS43, Dlo-RS2Z16, Dlo-RS2Z24, and Dlo-SR30 were highly expressed in all tissues. To clarify their function during SE, the transcript levels of Dlo-SR genes were analyzed at different four stages of SE, comprising non-embryonic callus (NEC), friable-embryogenic callus (EC), incomplete compact pro-embryogenic culture (ICpEC) and globular embryo (GE). Interestingly, the transcript levels of Dlo-RS2Z29 and Dlo-SR112 were increased in embryogenic cells compared with the NEC stage, whereas transcript levels of Dlo-RSZ20a, Dlo-RS43, Dlo-SC37, and Dlo-RS2Z16 were especially increased at the GE stage compared with the other stages. Alternative splicing events of Dlo-SR mRNA precursors (pre-mRNAs) was detected during SE, with totals of 41, 29, 35, and 44 events detected during NEC, EC, ICpEC, and GE respectively. Protein–protein interaction analysis showed that SR proteins were capable of interaction with each other. The results indicate that the alternative splicing of Dlo-SR pre-mRNAs occurs during SE and that Dlo-SR proteins may interact to regulate embryogenesis of longan.
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Affiliation(s)
- Xiaodong Chen
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Shuqi Huang
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Mengqi Jiang
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yukun Chen
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Xu XuHan
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute de la Recherche Interdisciplinaire de Toulouse, Toulouse, France
| | - Zihao Zhang
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Yuling Lin
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- * E-mail: (YL); (ZL)
| | - Zhongxiong Lai
- Institute of horticultural biotechnology, Fujian Agriculture and Forestry University, Fuzhou, China
- * E-mail: (YL); (ZL)
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Xu YF, Xu X, Gin A, Nshimiyimana JD, Mooers BHM, Caputi M, Hannafon BN, Ding WQ. SRSF1 regulates exosome microRNA enrichment in human cancer cells. Cell Commun Signal 2020; 18:130. [PMID: 32819370 PMCID: PMC7439691 DOI: 10.1186/s12964-020-00615-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/27/2020] [Indexed: 12/18/2022] Open
Abstract
Background Exosomes are extracellular vesicles containing a variety of biological molecules including microRNAs (miRNAs). We have recently demonstrated that certain miRNA species are selectively and highly enriched in pancreatic cancer exosomes with miR-1246 being the most abundant. Exosome miRNAs have been shown to mediate intercellular communication in the tumor microenvironment and promote cancer progression. Therefore, understanding how exosomes selectively enrich specific miRNAs to initiate exosome miRNA signaling in cancer cells is critical to advancing cancer exosome biology. Results The aim of this study was to identify RNA binding proteins responsible for selective enrichment of exosome miRNAs in cancer cells. A biotin-labeled miR-1246 probe was used to capture RNA binding proteins (RBPs) from PANC-1 cells. Among the RBPs identified through proteomic analysis, SRSF1, EIF3B and TIA1 were highly associated with the miR-1246 probe. RNA immunoprecipitation (RIP) and electrophoretic mobility shift assay (EMSA) confirmed the binding of SRSF1 to miR-1246. Lentivirus shRNA knockdown of SRSF1 in pancreatic cancer cells selectively reduced exosome miRNA enrichment whereas GFP-SRSF1 overexpression enhanced the enrichment as analyzed by next generation small RNA sequencing and qRT-PCR. miRNA sequence motif analysis identified a common motif shared by 36/45 of SRSF1-associated exosome miRNAs. EMSA confirmed that shared motif decoys inhibit the binding of SRSF1 to the miR-1246 sequence. Conclusions We conclude that SRSF1 mediates selective exosome miRNA enrichment in pancreatic cancer cells by binding to a commonly shared miRNA sequence motif. Video Abstract
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Affiliation(s)
- Yi-Fan Xu
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, 940 Stanton L. Young Blvd., BMSB 401A, Oklahoma City, OK, 73104, USA
| | - Xiaohui Xu
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, 940 Stanton L. Young Blvd., BMSB 401A, Oklahoma City, OK, 73104, USA.,Department of General Surgery, First People's Hospital of Taicang City, Taicang Affiliated Hospital of Soochow University, Suzhou, 215400, China
| | - Amy Gin
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, 940 Stanton L. Young Blvd., BMSB 401A, Oklahoma City, OK, 73104, USA
| | - Jean D Nshimiyimana
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, 940 Stanton L. Young Blvd., BMSB 401A, Oklahoma City, OK, 73104, USA
| | - Blaine H M Mooers
- Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Massimo Caputi
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Bethany N Hannafon
- Department of Obstetrics and Gynecology, Section of Gynecologic Oncology, Stephenson Cancer Center, College of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73103, USA.,Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Wei-Qun Ding
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, 940 Stanton L. Young Blvd., BMSB 401A, Oklahoma City, OK, 73104, USA. .,Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
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40
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HOTAIRM1 regulates neuronal differentiation by modulating NEUROGENIN 2 and the downstream neurogenic cascade. Cell Death Dis 2020; 11:527. [PMID: 32661334 PMCID: PMC7359305 DOI: 10.1038/s41419-020-02738-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 12/25/2022]
Abstract
Neuronal differentiation is a timely and spatially regulated process, relying on precisely orchestrated gene expression control. The sequential activation/repression of genes driving cell fate specification is achieved by complex regulatory networks, where transcription factors and noncoding RNAs work in a coordinated manner. Herein, we identify the long noncoding RNA HOTAIRM1 (HOXA Transcript Antisense RNA, Myeloid-Specific 1) as a new player in neuronal differentiation. We demonstrate that the neuronal-enriched HOTAIRM1 isoform epigenetically controls the expression of the proneural transcription factor NEUROGENIN 2 that is key to neuronal fate commitment and critical for brain development. We also show that HOTAIRM1 activity impacts on NEUROGENIN 2 downstream regulatory cascade, thus contributing to the achievement of proper neuronal differentiation timing. Finally, we identify the RNA-binding proteins HNRNPK and FUS as regulators of HOTAIRM1 biogenesis and metabolism. Our findings uncover a new regulatory layer underlying NEUROGENIN 2 transitory expression in neuronal differentiation and reveal a previously unidentified function for the neuronal-induced long noncoding RNA HOTAIRM1.
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41
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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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42
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Huang HH, Ferguson ID, Thornton AM, Bastola P, Lam C, Lin YHT, Choudhry P, Mariano MC, Marcoulis MD, Teo CF, Malato J, Phojanakong PJ, Martin TG, Wolf JL, Wong SW, Shah N, Hann B, Brooks AN, Wiita AP. Proteasome inhibitor-induced modulation reveals the spliceosome as a specific therapeutic vulnerability in multiple myeloma. Nat Commun 2020; 11:1931. [PMID: 32321912 PMCID: PMC7176739 DOI: 10.1038/s41467-020-15521-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 03/13/2020] [Indexed: 02/06/2023] Open
Abstract
Enhancing the efficacy of proteasome inhibitors (PI) is a central goal in myeloma therapy. We proposed that signaling-level responses after PI may reveal new mechanisms of action that can be therapeutically exploited. Unbiased phosphoproteomics after treatment with the PI carfilzomib surprisingly demonstrates the most prominent phosphorylation changes on splicing related proteins. Spliceosome modulation is invisible to RNA or protein abundance alone. Transcriptome analysis after PI demonstrates broad-scale intron retention, suggestive of spliceosome interference, as well as specific alternative splicing of protein homeostasis machinery components. These findings lead us to evaluate direct spliceosome inhibition in myeloma, which synergizes with carfilzomib and shows potent anti-tumor activity. Functional genomics and exome sequencing further support the spliceosome as a specific vulnerability in myeloma. Our results propose splicing interference as an unrecognized modality of PI mechanism, reveal additional modes of spliceosome modulation, and suggest spliceosome targeting as a promising therapeutic strategy in myeloma.
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Affiliation(s)
- Hector H Huang
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Ian D Ferguson
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Alexis M Thornton
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA, USA
| | - Prabhakar Bastola
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Christine Lam
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Yu-Hsiu T Lin
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Priya Choudhry
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Margarette C Mariano
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Makeba D Marcoulis
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA
| | - Chin Fen Teo
- Department of Physiology, University of California, San Francisco, CA, USA
| | - Julia Malato
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Paul J Phojanakong
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Thomas G Martin
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco, CA, USA
| | - Jeffrey L Wolf
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco, CA, USA
| | - Sandy W Wong
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco, CA, USA
| | - Nina Shah
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.,Department of Medicine, University of California, San Francisco, CA, USA
| | - Byron Hann
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA
| | - Angela N Brooks
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA, USA
| | - Arun P Wiita
- Department of Laboratory Medicine, University of California, San Francisco, CA, USA. .,Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA, USA.
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43
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Che Y, Fu L. Aberrant expression and regulatory network of splicing factor-SRSF3 in tumors. J Cancer 2020; 11:3502-3511. [PMID: 32284746 PMCID: PMC7150454 DOI: 10.7150/jca.42645] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 02/26/2020] [Indexed: 12/14/2022] Open
Abstract
Alternative splicing facilitates the splicing of precursor RNA into different isoforms. Alternatively spliced transcripts often exhibit antagonistic functions or differential temporal or spatial expression patterns. There is increasing evidence that alternative splicing, especially by the serine-arginine rich (SR) protein family, leads to abnormal expression patterns and is closely related to the development of cancer. SRSF3, also known as SRp20, is a splicing factor. Through alternative splicing, it plays important roles in regulating various biological functions, such as cell cycle, cell proliferation, migration and invasion, under pathological and physiological conditions. Deregulation of SRSF3 is an essential feature of cancers. SRSF3 is also considered a candidate therapeutic target. Therefore, the involvement of abnormal splicing in tumorigenesis and the regulation of splicing factors deserve further analysis and discussion. Here, we summarize the function of SRSF3-regulated alternative transcripts in cancer cell biology at different stages of tumor development and the regulation of SRSF3 in tumorigenesis.
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Affiliation(s)
- Yingying Che
- Institute of Chronic Disease, Qingdao Municipal Hospital, Qingdao University, Qingdao 266000, China
| | - Lin Fu
- Institute of Chronic Disease, Qingdao Municipal Hospital, Qingdao University, Qingdao 266000, China
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44
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Kundinger SR, Bishof I, Dammer EB, Duong DM, Seyfried NT. Middle-Down Proteomics Reveals Dense Sites of Methylation and Phosphorylation in Arginine-Rich RNA-Binding Proteins. J Proteome Res 2020; 19:1574-1591. [PMID: 31994892 DOI: 10.1021/acs.jproteome.9b00633] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Post-translational modifications (PTMs) within arginine (Arg)-rich RNA-binding proteins, such as phosphorylation and methylation, regulate multiple steps in RNA metabolism. However, the identification of PTMs within Arg-rich domains with complete trypsin digestion is extremely challenging due to the high density of Arg residues within these proteins. Here, we report a middle-down proteomic approach coupled with electron-transfer dissociation (ETD) mass spectrometry to map previously unknown sites of phosphorylation and methylation within the Arg-rich domains of U1-70K and structurally similar RNA-binding proteins from nuclear extracts of human embryonic kidney (HEK)-293T cells. Notably, the Arg-rich domains in RNA-binding proteins are densely modified by methylation and phosphorylation compared with the remainder of the proteome, with methylation and phosphorylation favoring RSRS motifs. Although they favor a common motif, analysis of combinatorial PTMs within RSRS motifs indicates that phosphorylation and methylation do not often co-occur, suggesting that they may functionally oppose one another. Furthermore, we show that phosphorylation may modify interactions between Arg-rich proteins, as serine-arginine splicing factor 2 (SRSF2) has a stronger association with U1-70K and LUC7L3 upon dephosphorylation. Collectively, these findings suggest that the level of PTMs within Arg-rich domains may be among the highest in the proteome and a possible unexplored regulator of RNA-binding protein interactions.
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45
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Masaki S, Kabuto T, Suzuki K, Kataoka N. Multiple nuclear localization sequences in SRSF4 protein. Genes Cells 2020; 25:327-333. [PMID: 32050040 DOI: 10.1111/gtc.12756] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 11/29/2022]
Abstract
SRSF4 is one of the members of serine-/arginine (SR)-rich protein family involved in both constitutive and alternative splicing. SRSF4 is localized in the nucleus with speckled pattern, but its nuclear localization signal was not determined. Here, we have identified nuclear localization signals (NLSs) of SRSF4 by using a pyruvate kinase fusion system. As expected, arginine-/serine (RS)-rich domain of SRSF4 confers nuclear localization activity when it is fused to PK protein. We then further delineated the minimum sequences for nuclear localization in RS domain of SRSF4. Surprisingly, RS-rich region does not always have a nuclear localization activity. In addition, basic amino acid stretches that resemble to classical-type NLSs were identified. These results strongly suggest that SRSF4 protein uses two different nuclear import pathways with multiple NLSs in RS domain.
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Affiliation(s)
- So Masaki
- Laboratory for Malignancy Control Research, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Laboratory of Molecular Medicinal Science, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Takafumi Kabuto
- Laboratory of Anatomy and Developmental Biology, Kyoto University School of Medicine, Kyoto, Japan
| | - Kenji Suzuki
- Laboratory of Molecular Medicinal Science, Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan
| | - Naoyuki Kataoka
- Laboratory for Malignancy Control Research, Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan.,Laboratory of Anatomy and Developmental Biology, Kyoto University School of Medicine, Kyoto, Japan.,Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Tokyo, Japan
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46
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Rahman MA, Lin KT, Bradley RK, Abdel-Wahab O, Krainer AR. Recurrent SRSF2 mutations in MDS affect both splicing and NMD. Genes Dev 2020; 34:413-427. [PMID: 32001512 PMCID: PMC7050488 DOI: 10.1101/gad.332270.119] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Accepted: 12/20/2019] [Indexed: 12/23/2022]
Abstract
Oncogenic mutations in the RNA splicing factors SRSF2, SF3B1, and U2AF1 are the most frequent class of mutations in myelodysplastic syndromes and are also common in clonal hematopoiesis, acute myeloid leukemia, chronic lymphocytic leukemia, and a variety of solid tumors. They cause genome-wide splicing alterations that affect important regulators of hematopoiesis. Several mRNA isoforms promoted by the various splicing factor mutants comprise a premature termination codon (PTC) and are therefore potential targets of nonsense-mediated mRNA decay (NMD). In light of the mechanistic relationship between splicing and NMD, we sought evidence for a specific role of mutant SRSF2 in NMD. We show that SRSF2 Pro95 hot spot mutations elicit enhanced mRNA decay, which is dependent on sequence-specific RNA binding and splicing. SRSF2 mutants enhance the deposition of exon junction complexes (EJCs) downstream from the PTC through RNA-mediated molecular interactions. This architecture then favors the association of key NMD factors to elicit mRNA decay. Gene-specific blocking of EJC deposition by antisense oligonucleotides circumvents aberrant NMD promoted by mutant SRSF2, restoring the expression of PTC-containing transcript. Our study uncovered critical effects of SRSF2 mutants in hematologic malignancies, reflecting the regulation at multiple levels of RNA metabolism, from splicing to decay.
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Affiliation(s)
| | - Kuan-Ting Lin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
| | - Robert K Bradley
- Computational Biology Program, Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.,Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA
| | - Omar Abdel-Wahab
- Memorial Sloan Kettering Cancer Center, New York, New York 10065, USA
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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47
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Li M, Wu P, Yang Z, Deng S, Ni L, Zhang Y, Jin L, Pan Y. miR-193a-5p promotes pancreatic cancer cell metastasis through SRSF6-mediated alternative splicing of OGDHL and ECM1. Am J Cancer Res 2020; 10:38-59. [PMID: 32064152 PMCID: PMC7017744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 12/23/2019] [Indexed: 06/10/2023] Open
Abstract
MicroRNAs (miRNAs) are short and non-coding RNAs binding to 3'UTR of target mRNAs to downregulate their expression. Recent studies have shown that miRNAs indirectly regulated alternative splicing (AS) by targeting splicing factors and caused shifts in splicing patterns of target genes. However, the roles of miRNA-regulating splicing factors in pancreatic cancer progression remain unknown. Herein, we reported that miR-193a-5p was markedly upregulated in pancreatic cancer tissues and cells and correlated with clinical outcomes of pancreatic cancer patients. Overexpression of miR-193a-5p contributed to the metastasis of pancreatic cancer cells both in vitro and in vivo. The mechanistic investigation suggested that miR-193a-5p modulated oxoglutarate dehydrogenase-like (OGDHL) and extracellular matrix protein 1 (ECM1) AS by targeting serine/arginine-rich splicing factor 6 (SRSF6), leading to the activation of the epithelial-to-mesenchymal transition (EMT) process. Together, our findings highlighted the role of miR-193a-5p-targeting SRSF6 in pancreatic cancer metastasis, which may serve as a novel target for pancreatic cancer diagnosis and therapy.
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Affiliation(s)
- Manman Li
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Pandi Wu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Zhaocong Yang
- Department of Cardiothoracic Surgery, Children’s Hospital of Nanjing Medical UniversityNanjing 21008, PR China
| | - Siwei Deng
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Lingyu Ni
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Yanfeng Zhang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Liang Jin
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
| | - Yi Pan
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, School of Life Science and Technology, China Pharmaceutical University24 Tongjiaxiang Avenue, Nanjing, Jiangsu, PR China
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48
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Aznarez I, Nomakuchi TT, Tetenbaum-Novatt J, Rahman MA, Fregoso O, Rees H, Krainer AR. Mechanism of Nonsense-Mediated mRNA Decay Stimulation by Splicing Factor SRSF1. Cell Rep 2019; 23:2186-2198. [PMID: 29768215 PMCID: PMC5999336 DOI: 10.1016/j.celrep.2018.04.039] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 02/20/2018] [Accepted: 04/06/2018] [Indexed: 11/25/2022] Open
Abstract
The splicing factor SRSF1 promotes nonsense-mediated mRNA decay (NMD), a quality control mechanism that degrades mRNAs with premature termination codons (PTCs). Here we show that transcript-bound SRSF1 increases the binding of NMD factor UPF1 to mRNAs while in, or associated with, the nucleus, bypassing UPF2 recruitment and promoting NMD. SRSF1 promotes NMD when positioned downstream of a PTC, which resembles the mode of action of exon junction complex (EJC) and NMD factors. Moreover, splicing and/or EJC deposition increase the effect of SRSF1 on NMD. Lastly, SRSF1 enhances NMD of PTC-containing endogenous transcripts that result from various events. Our findings reveal an alternative mechanism for UPF1 recruitment, uncovering an additional connection between splicing and NMD. SRSF1’s role in the mRNA’s journey from splicing to decay has broad implications for gene expression regulation and genetic diseases.
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Affiliation(s)
- Isabel Aznarez
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | | | | | | | - Oliver Fregoso
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Holly Rees
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA
| | - Adrian R Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
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49
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Park S, Brugiolo M, Akerman M, Das S, Urbanski L, Geier A, Kesarwani AK, Fan M, Leclair N, Lin KT, Hu L, Hua I, George J, Muthuswamy SK, Krainer AR, Anczuków O. Differential Functions of Splicing Factors in Mammary Transformation and Breast Cancer Metastasis. Cell Rep 2019; 29:2672-2688.e7. [PMID: 31775037 PMCID: PMC6936330 DOI: 10.1016/j.celrep.2019.10.110] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/09/2019] [Accepted: 10/28/2019] [Indexed: 12/28/2022] Open
Abstract
Misregulation of alternative splicing is a hallmark of human tumors, yet to what extent and how it contributes to malignancy are only beginning to be unraveled. Here, we define which members of the splicing factor SR and SR-like families contribute to breast cancer and uncover differences and redundancies in their targets and biological functions. We identify splicing factors frequently altered in human breast tumors and assay their oncogenic functions using breast organoid models. We demonstrate that not all splicing factors affect mammary tumorigenesis in MCF-10A cells. Specifically, the upregulation of SRSF4, SRSF6, or TRA2β disrupts acinar morphogenesis and promotes cell proliferation and invasion in MCF-10A cells. By characterizing the targets of these oncogenic splicing factors, we identify shared spliced isoforms associated with well-established cancer hallmarks. Finally, we demonstrate that TRA2β is regulated by the MYC oncogene, plays a role in metastasis maintenance in vivo, and its levels correlate with breast cancer patient survival.
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Affiliation(s)
- SungHee Park
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA,These authors contributed equally
| | - Mattia Brugiolo
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA,These authors contributed equally
| | - Martin Akerman
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA,Envisagenics Inc., New York, NY, USA,These authors contributed equally
| | - Shipra Das
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA,These authors contributed equally
| | - Laura Urbanski
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA,Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | | | | | - Martin Fan
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Nathan Leclair
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA,Graduate Program in Genetics and Development, UConn Health, Farmington, CT, USA
| | - Kuan-Ting Lin
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Leo Hu
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Ian Hua
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA
| | - Joshy George
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA,Institute for Systems Genomics, UConn Health, Farmington, CT, USA
| | - Senthil K. Muthuswamy
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA,Departments of Medicine and Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Adrian R. Krainer
- Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA,Correspondence: (O.A.), (A.R.K.)
| | - Olga Anczuków
- The Jackson Laboratory for Genomic Medicine, Farmington, CT, USA; Cold Spring Harbor Laboratory, Cold Spring Harbor, NY, USA; Institute for Systems Genomics, UConn Health, Farmington, CT, USA; Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, USA.
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50
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Kutluay SB, Emery A, Penumutchu SR, Townsend D, Tenneti K, Madison MK, Stukenbroeker AM, Powell C, Jannain D, Tolbert BS, Swanstrom RI, Bieniasz PD. Genome-Wide Analysis of Heterogeneous Nuclear Ribonucleoprotein (hnRNP) Binding to HIV-1 RNA Reveals a Key Role for hnRNP H1 in Alternative Viral mRNA Splicing. J Virol 2019; 93:e01048-19. [PMID: 31413137 PMCID: PMC6803249 DOI: 10.1128/jvi.01048-19] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Accepted: 07/23/2019] [Indexed: 02/06/2023] Open
Abstract
Alternative splicing of HIV-1 mRNAs increases viral coding potential and controls the levels and timing of gene expression. HIV-1 splicing is regulated in part by heterogeneous nuclear ribonucleoproteins (hnRNPs) and their viral target sequences, which typically repress splicing when studied outside their native viral context. Here, we determined the location and extent of hnRNP binding to HIV-1 mRNAs and their impact on splicing in a native viral context. Notably, hnRNP A1, hnRNP A2, and hnRNP B1 bound to many dispersed sites across viral mRNAs. Conversely, hnRNP H1 bound to a few discrete purine-rich sequences, a finding that was mirrored in vitro hnRNP H1 depletion and mutation of a prominent viral RNA hnRNP H1 binding site decreased the use of splice acceptor A1, causing a deficit in Vif expression and replicative fitness. This quantitative framework for determining the regulatory inputs governing alternative HIV-1 splicing revealed an unexpected splicing enhancer role for hnRNP H1 through binding to its target element.IMPORTANCE Alternative splicing of HIV-1 mRNAs is an essential yet quite poorly understood step of virus replication that enhances the coding potential of the viral genome and allows the temporal regulation of viral gene expression. Although HIV-1 constitutes an important model system for general studies of the regulation of alternative splicing, the inputs that determine the efficiency with which splice sites are utilized remain poorly defined. Our studies provide an experimental framework to study an essential step of HIV-1 replication more comprehensively and in much greater detail than was previously possible and reveal novel cis-acting elements regulating HIV-1 splicing.
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Affiliation(s)
- Sebla B Kutluay
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Ann Emery
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | | | - Dana Townsend
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Kasyap Tenneti
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Michaela K Madison
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Amanda M Stukenbroeker
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Chelsea Powell
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
| | - David Jannain
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
| | - Blanton S Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio, USA
| | - Ronald I Swanstrom
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
- UNC Center for AIDS Research, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Paul D Bieniasz
- Laboratory of Retrovirology, The Rockefeller University, New York, New York, USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, New York, USA
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