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Roesmann F, Müller L, Klaassen K, Heß S, Widera M. Interferon-Regulated Expression of Cellular Splicing Factors Modulates Multiple Levels of HIV-1 Gene Expression and Replication. Viruses 2024; 16:938. [PMID: 38932230 PMCID: PMC11209495 DOI: 10.3390/v16060938] [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: 04/30/2024] [Revised: 05/31/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024] Open
Abstract
Type I interferons (IFN-Is) are pivotal in innate immunity against human immunodeficiency virus I (HIV-1) by eliciting the expression of IFN-stimulated genes (ISGs), which encompass potent host restriction factors. While ISGs restrict the viral replication within the host cell by targeting various stages of the viral life cycle, the lesser-known IFN-repressed genes (IRepGs), including RNA-binding proteins (RBPs), affect the viral replication by altering the expression of the host dependency factors that are essential for efficient HIV-1 gene expression. Both the host restriction and dependency factors determine the viral replication efficiency; however, the understanding of the IRepGs implicated in HIV-1 infection remains greatly limited at present. This review provides a comprehensive overview of the current understanding regarding the impact of the RNA-binding protein families, specifically the two families of splicing-associated proteins SRSF and hnRNP, on HIV-1 gene expression and viral replication. Since the recent findings show specifically that SRSF1 and hnRNP A0 are regulated by IFN-I in various cell lines and primary cells, including intestinal lamina propria mononuclear cells (LPMCs) and peripheral blood mononuclear cells (PBMCs), we particularly discuss their role in the context of the innate immunity affecting HIV-1 replication.
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Affiliation(s)
- Fabian Roesmann
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Lisa Müller
- Institute of Virology, Medical Faculty, University Hospital Düsseldorf, Heinrich-Heine-University Düsseldorf, Universitätsstr. 1, 40225 Düsseldorf, Germany
| | - Katleen Klaassen
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Stefanie Heß
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Marek Widera
- Institute for Medical Virology, University Hospital Frankfurt, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
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Li WJ, Huang Y, Lin YA, Zhang BD, Li MY, Zou YQ, Hu GS, He YH, Yang JJ, Xie BL, Huang HH, Deng X, Liu W. Targeting PRMT1-mediated SRSF1 methylation to suppress oncogenic exon inclusion events and breast tumorigenesis. Cell Rep 2023; 42:113385. [PMID: 37938975 DOI: 10.1016/j.celrep.2023.113385] [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: 01/14/2023] [Revised: 08/10/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023] Open
Abstract
PRMT1 plays a vital role in breast tumorigenesis; however, the underlying molecular mechanisms remain incompletely understood. Herein, we show that PRMT1 plays a critical role in RNA alternative splicing, with a preference for exon inclusion. PRMT1 methylome profiling identifies that PRMT1 methylates the splicing factor SRSF1, which is critical for SRSF1 phosphorylation, SRSF1 binding with RNA, and exon inclusion. In breast tumors, PRMT1 overexpression is associated with increased SRSF1 arginine methylation and aberrant exon inclusion, which are critical for breast cancer cell growth. In addition, we identify a selective PRMT1 inhibitor, iPRMT1, which potently inhibits PRMT1-mediated SRSF1 methylation, exon inclusion, and breast cancer cell growth. Combination treatment with iPRMT1 and inhibitors targeting SRSF1 phosphorylation exhibits an additive effect of suppressing breast cancer cell growth. In conclusion, our study dissects a mechanism underlying PRMT1-mediated RNA alternative splicing. Thus, PRMT1 has great potential as a therapeutic target in breast cancer treatment.
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Affiliation(s)
- Wen-Juan Li
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Ying Huang
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yi-An Lin
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Bao-Ding Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China
| | - Mei-Yan Li
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yi-Qin Zou
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Guo-Sheng Hu
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Yao-Hui He
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Jing-Jing Yang
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China
| | - Bing-Lan Xie
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China
| | - Hai-Hua Huang
- Department of Pathology, The Second Affiliated Hospital, Shantou University Medical College, Shantou, Guangdong, China
| | - Xianming Deng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China.
| | - Wen Liu
- State Key Laboratory of Cellular Stress Biology, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian, China; Xiang An Biomedicine Laboratory, School of Pharmaceutical Sciences, Faculty of Medicine and Life Sciences, Xiamen University, Xiang'an South Road, Xiamen, Fujian 361102, China.
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Dery KJ, Wong Z, Wei M, Kupiec-Weglinski JW. Mechanistic Insights into Alternative Gene Splicing in Oxidative Stress and Tissue Injury. Antioxid Redox Signal 2023. [PMID: 37776178 DOI: 10.1089/ars.2023.0437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/01/2023]
Abstract
Significance: Oxidative stress (OS) and inflammation are inducers of tissue injury. Alternative splicing (AS) is an essential regulatory step for diversifying the eukaryotic proteome. Human diseases link AS to OS; however, the underlying mechanisms must be better understood. Recent Advances: Genome‑wide profiling studies identify new differentially expressed genes induced by OS-dependent ischemia/reperfusion injury. Overexpression of RNA-binding protein RBFOX1 protects against inflammation. Hypoxia-inducible factor-1α directs polypyrimidine tract binding protein 1 to regulate mouse carcinoembryonic antigen-related cell adhesion molecule 1 (Ceacam1) AS under OS conditions. Heterogeneous nuclear ribonucleoprotein L variant 1 contains an RGG/RG motif that coordinates with transcription factors to influence human CEACAM1 AS. Hypoxia intervention involving short interfering RNAs directed to long-noncoding RNA 260 polarizes M2 macrophages toward an anti-inflammatory phenotype and alleviates OS by inhibiting IL-28RA gene AS. Critical Issues: Protective mechanisms that eliminate reactive oxygen species (ROS) are important for resolving imbalances that lead to chronic inflammation. Defects in AS can cause ROS generation, cell death regulation, and the activation of innate and adaptive immune factors. We propose that AS pathways link redox regulation to the activation or suppression of the inflammatory response during cellular stress. Future Directions: Emergent studies using molecule-mediated RNA splicing are being conducted to exploit the immunogenicity of AS protein products. Deciphering the mechanisms that connect misspliced OS and pathologies should remain a priority. Controlled release of RNA directly into cells with clinical applications is needed as the demand for innovative nucleic acid delivery systems continues to be demonstrated.
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Affiliation(s)
- Kenneth J Dery
- The Dumont-UCLA Transplantation Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Zeriel Wong
- The Dumont-UCLA Transplantation Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Megan Wei
- The Dumont-UCLA Transplantation Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Jerzy W Kupiec-Weglinski
- The Dumont-UCLA Transplantation Center, Division of Liver and Pancreas Transplantation, Department of Surgery, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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Liao C, Li M, Chen X, Tang C, Quan J, Bode AM, Cao Y, Luo X. Anoikis resistance and immune escape mediated by Epstein-Barr virus-encoded latent membrane protein 1-induced stabilization of PGC-1α promotes invasion and metastasis of nasopharyngeal carcinoma. J Exp Clin Cancer Res 2023; 42:261. [PMID: 37803433 PMCID: PMC10559433 DOI: 10.1186/s13046-023-02835-6] [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: 04/21/2023] [Accepted: 09/17/2023] [Indexed: 10/08/2023] Open
Abstract
BACKGROUND Epstein-Barr virus (EBV) is the first discovered human tumor virus that is associated with a variety of malignancies of both lymphoid and epithelial origin including nasopharyngeal carcinoma (NPC). The EBV-encoded latent membrane protein 1 (LMP1) has been well-defined as a potent oncogenic protein, which is intimately correlated with NPC pathogenesis. Anoikis is considered to be a physiological barrier to metastasis, and avoiding anoikis is a major hallmark of metastasis. However, the role of LMP1 in anoikis-resistance and metastasis of NPC has not been fully identified. METHODS Trypan blue staining, colony formation assay, flow cytometry, and TUNEL staining, as well as the detection of apoptosis and anoikis resistance-related markers was applied to evaluate the anoikis-resistant capability of NPC cells cultured in ultra-low adhesion condition. Co-immunoprecipitation (Co-IP) experiment was performed to determine the interaction among LMP1, PRMT1 and PGC-1α. Ex vivo ubiquitination assay was used to detect the ubiquitination level of PGC-1α. Anoikis- resistant LMP1-positive NPC cell lines were established and applied for the xenograft and metastatic animal experiments. RESULTS Our current findings reveal the role of LMP1-stabilized peroxisome proliferator activated receptor coactivator-1a (PGC-1α) in anoikis resistance and immune escape to support the invasion and metastasis of NPC. Mechanistically, LMP1 enhances PGC-1α protein stability by promoting the interaction between arginine methyltransferase 1 (PRMT1) and PGC-1α to elevate the methylation modification of PGC-1α, thus endowing NPC cells with anoikis-resistance. Meanwhile, PGC-1α mediates the immune escape induced by LMP1 by coactivating with STAT3 to transcriptionally up-regulate PD-L1 expression. CONCLUSION Our work provides insights into how virus-encoded proteins recruit and interact with host regulatory elements to facilitate the malignant progression of NPC. Therefore, targeting PGC-1α or PRMT1-PGC-1α interaction might be exploited for therapeutic gain for EBV-associated malignancies.
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Affiliation(s)
- Chaoliang Liao
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, PR China
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
- Department of Medical Science Laboratory, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, 545007, PR China
| | - Min Li
- Department of Oncology, Nanjing Hospital of Chinese Medicine Affiliated to Nanjing University of Chinese Medicine, Nanjing, Jiangsu, 210023, PR China
| | - Xue Chen
- Early Clinical Trial Center, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, PR China
| | - Chenpeng Tang
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, PR China
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Jing Quan
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, PR China
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Ann M Bode
- The Hormel Institute, University of Minnesota, Austin, MN, 55912, USA
| | - Ya Cao
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China
| | - Xiangjian Luo
- NHC Key Laboratory of Carcinogenesis and Hunan Key Laboratory of Oncotarget Gene, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, 410013, PR China.
- Key Laboratory of Carcinogenesis and Invasion, Chinese Ministry of Education, Cancer Research Institute, School of Basic Medicine, Central South University, Changsha, Hunan, 410078, PR China.
- National Health Commission (NHC) Key Laboratory of Nanobiological Technology, Xiangya Hospital, Central South University, Changsha, Hunan, 410078, PR China.
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Li D, Yu W, Lai M. Towards understandings of serine/arginine-rich splicing factors. Acta Pharm Sin B 2023; 13:3181-3207. [PMID: 37655328 PMCID: PMC10465970 DOI: 10.1016/j.apsb.2023.05.022] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 04/13/2023] [Accepted: 05/06/2023] [Indexed: 09/02/2023] Open
Abstract
Serine/arginine-rich splicing factors (SRSFs) refer to twelve RNA-binding proteins which regulate splice site recognition and spliceosome assembly during precursor messenger RNA splicing. SRSFs also participate in other RNA metabolic events, such as transcription, translation and nonsense-mediated decay, during their shuttling between nucleus and cytoplasm, making them indispensable for genome diversity and cellular activity. Of note, aberrant SRSF expression and/or mutations elicit fallacies in gene splicing, leading to the generation of pathogenic gene and protein isoforms, which highlights the therapeutic potential of targeting SRSF to treat diseases. In this review, we updated current understanding of SRSF structures and functions in RNA metabolism. Next, we analyzed SRSF-induced aberrant gene expression and their pathogenic outcomes in cancers and non-tumor diseases. The development of some well-characterized SRSF inhibitors was discussed in detail. We hope this review will contribute to future studies of SRSF functions and drug development targeting SRSFs.
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Affiliation(s)
- Dianyang Li
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Wenying Yu
- State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China
| | - Maode Lai
- School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing 210009, China
- Department of Pathology, Research Unit of Intelligence Classification of Tumor Pathology and Precision Therapy, Chinese Academy of Medical Science (2019RU042), Key Laboratory of Disease Proteomics of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou 310058, China
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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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Cura V, Cavarelli J. Structure, Activity and Function of the PRMT2 Protein Arginine Methyltransferase. Life (Basel) 2021; 11:1263. [PMID: 34833139 PMCID: PMC8623767 DOI: 10.3390/life11111263] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Revised: 11/10/2021] [Accepted: 11/12/2021] [Indexed: 11/17/2022] Open
Abstract
PRMT2 belongs to the protein arginine methyltransferase (PRMT) family, which catalyzes the arginine methylation of target proteins. As a type I enzyme, PRMT2 produces asymmetric dimethyl arginine and has been shown to have weak methyltransferase activity on histone substrates in vitro, suggesting that its authentic substrates have not yet been found. PRMT2 contains the canonical PRMT methylation core and a unique Src homology 3 domain. Studies have demonstrated its clear implication in many different cellular processes. PRMT2 acts as a coactivator of several nuclear hormone receptors and is known to interact with a multitude of splicing-related proteins. Furthermore, PRMT2 is aberrantly expressed in several cancer types, including breast cancer and glioblastoma. These reports highlight the crucial role played by PRMT2 and the need for a better characterization of its activity and cellular functions.
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Affiliation(s)
- Vincent Cura
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France;
- Centre National de la Recherche Scientifique, UMR 7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France
- Université de Strasbourg, 67000 Strasbourg, France
| | - Jean Cavarelli
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, 67404 Illkirch, France;
- Centre National de la Recherche Scientifique, UMR 7104, 67404 Illkirch, France
- Institut National de la Santé et de la Recherche Médicale, U1258, 67404 Illkirch, France
- Université de Strasbourg, 67000 Strasbourg, France
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Structure, Activity, and Function of PRMT1. Life (Basel) 2021; 11:life11111147. [PMID: 34833023 PMCID: PMC8619983 DOI: 10.3390/life11111147] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 10/25/2021] [Accepted: 10/25/2021] [Indexed: 01/10/2023] Open
Abstract
PRMT1, the major protein arginine methyltransferase in mammals, catalyzes monomethylation and asymmetric dimethylation of arginine side chains in proteins. Initially described as a regulator of chromatin dynamics through the methylation of histone H4 at arginine 3 (H4R3), numerous non-histone substrates have since been identified. The variety of these substrates underlines the essential role played by PRMT1 in a large number of biological processes such as transcriptional regulation, signal transduction or DNA repair. This review will provide an overview of the structural, biochemical and cellular features of PRMT1. After a description of the genomic organization and protein structure of PRMT1, special consideration was given to the regulation of PRMT1 enzymatic activity. Finally, we discuss the involvement of PRMT1 in embryonic development, DNA damage repair, as well as its participation in the initiation and progression of several types of cancers.
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Ruta V, Pagliarini V, Sette C. Coordination of RNA Processing Regulation by Signal Transduction Pathways. Biomolecules 2021; 11:biom11101475. [PMID: 34680108 PMCID: PMC8533259 DOI: 10.3390/biom11101475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/01/2021] [Accepted: 10/05/2021] [Indexed: 02/06/2023] Open
Abstract
Signal transduction pathways transmit the information received from external and internal cues and generate a response that allows the cell to adapt to changes in the surrounding environment. Signaling pathways trigger rapid responses by changing the activity or localization of existing molecules, as well as long-term responses that require the activation of gene expression programs. All steps involved in the regulation of gene expression, from transcription to processing and utilization of new transcripts, are modulated by multiple signal transduction pathways. This review provides a broad overview of the post-translational regulation of factors involved in RNA processing events by signal transduction pathways, with particular focus on the regulation of pre-mRNA splicing, cleavage and polyadenylation. The effects of several post-translational modifications (i.e., sumoylation, ubiquitination, methylation, acetylation and phosphorylation) on the expression, subcellular localization, stability and affinity for RNA and protein partners of many RNA-binding proteins are highlighted. Moreover, examples of how some of the most common signal transduction pathways can modulate biological processes through changes in RNA processing regulation are illustrated. Lastly, we discuss challenges and opportunities of therapeutic approaches that correct RNA processing defects and target signaling molecules.
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Affiliation(s)
- Veronica Ruta
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Vittoria Pagliarini
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Organoids Facility, IRCCS Fondazione Policlinico Universitario Agostino Gemelli, 00168 Rome, Italy
| | - Claudio Sette
- Department of Neuroscience, Section of Human Anatomy, Catholic University of the Sacred Heart, 00168 Rome, Italy; (V.R.); (V.P.)
- Laboratory of Neuroembryology, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Correspondence:
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Long Noncoding RNA FENDRR Inhibits Lung Fibroblast Proliferation via a Reduction of β-Catenin. Int J Mol Sci 2021; 22:ijms22168536. [PMID: 34445242 PMCID: PMC8395204 DOI: 10.3390/ijms22168536] [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: 07/10/2021] [Revised: 07/30/2021] [Accepted: 08/01/2021] [Indexed: 02/06/2023] Open
Abstract
Idiopathic Pulmonary Fibrosis (IPF) is a chronic, progressive, and usually lethal lung disease and it has been widely accepted that fibroblast proliferation is one of the key characteristics of IPF. Long noncoding RNAs (lncRNAs) play vital roles in the pathogenesis of many diseases. In this study, we investigated the role of lncRNA FENDRR on fibroblast proliferation. Human lung fibroblasts stably overexpressing FENDRR showed a reduced cell proliferation compared to those expressing the control vector. On the other hand, FENDRR silencing increased fibroblast proliferation. FENDRR bound serine-arginine rich splicing factor 9 (SRSF9) and inhibited the phosphorylation of p70 ribosomal S6 kinase 1 (PS6K), a downstream protein of the mammalian target of rapamycin (mTOR) signaling. Silencing SRSF9 reduced fibroblast proliferation. FENDRR reduced β-catenin protein, but not mRNA levels. The reduction of β-catenin protein levels in lung fibroblasts by gene silencing or chemical inhibitor decreased fibroblast proliferation. Adenovirus-mediated FENDRR transfer to the lungs of mice reduced asbestos-induced fibrotic lesions and collagen deposition. RNA sequencing of lung tissues identified 7 cell proliferation-related genes that were up-regulated by asbestos but reversed by FENDRR. In conclusion, FENDRR inhibits fibroblast proliferation and functions as an anti-fibrotic lncRNA.
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Du JX, Zhu GQ, Cai JL, Wang B, Luo YH, Chen C, Cai CZ, Zhang SJ, Zhou J, Fan J, Zhu W, Dai Z. Splicing factors: Insights into their regulatory network in alternative splicing in cancer. Cancer Lett 2020; 501:83-104. [PMID: 33309781 DOI: 10.1016/j.canlet.2020.11.043] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 12/18/2022]
Abstract
More than 95% of all human genes are alternatively spliced after transcription, which enriches the diversity of proteins and regulates transcript and/or protein levels. The splicing isoforms produced from the same gene can manifest distinctly, even exerting opposite effects. Mounting evidence indicates that the alternative splicing (AS) mechanism is ubiquitous in various cancers and drives the generation and maintenance of various hallmarks of cancer, such as enhanced proliferation, inhibited apoptosis, invasion and metastasis, and angiogenesis. Splicing factors (SFs) play pivotal roles in the recognition of splice sites and the assembly of spliceosomes during AS. In this review, we mainly discuss the similarities and differences of SF domains, the details of SF function in AS, the effect of SF-driven pathological AS on different hallmarks of cancer, and the main drivers of SF expression level and subcellular localization. In addition, we briefly introduce the application prospects of targeted therapeutic strategies, including small-molecule inhibitors, siRNAs and splice-switching oligonucleotides (SSOs), from three perspectives (drivers, SFs and pathological AS). Finally, we share our insights into the potential direction of research on SF-centric AS-related regulatory networks.
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Affiliation(s)
- Jun-Xian Du
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Gui-Qi Zhu
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Jia-Liang Cai
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Biao Wang
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Yi-Hong Luo
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Cong Chen
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Cheng-Zhe Cai
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Si-Jia Zhang
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China
| | - Jian Zhou
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Jia Fan
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China
| | - Wei Zhu
- Department of General Surgery, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China.
| | - Zhi Dai
- Liver Cancer Institute, Zhongshan Hospital, Fudan University & State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200032, China; Key Laboratory of Carcinogenesis and Cancer Invasion, Fudan University, Ministry of Education, Shanghai, 200032, China.
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12
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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: 38] [Impact Index Per Article: 9.5] [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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13
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Cherry S, Lynch KW. Alternative splicing and cancer: insights, opportunities, and challenges from an expanding view of the transcriptome. Genes Dev 2020; 34:1005-1016. [PMID: 32747477 PMCID: PMC7397854 DOI: 10.1101/gad.338962.120] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Over the past decade there has been increased awareness of the potential role of alternative splicing in the etiology of cancer. In particular, advances in RNA-Sequencing technology and analysis has led to a wave of discoveries in the last few years regarding the causes and functional relevance of alternative splicing in cancer. Here we discuss the current understanding of the connections between splicing and cancer, with a focus on the most recent findings. We also discuss remaining questions and challenges that must be addressed in order to use our knowledge of splicing to guide the diagnosis and treatment of cancer.
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Affiliation(s)
- Sara Cherry
- Department of Pathology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | - Kristen W Lynch
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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14
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Zheng X, Peng Q, Wang L, Zhang X, Huang L, Wang J, Qin Z. Serine/arginine-rich splicing factors: the bridge linking alternative splicing and cancer. Int J Biol Sci 2020; 16:2442-2453. [PMID: 32760211 PMCID: PMC7378643 DOI: 10.7150/ijbs.46751] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/22/2020] [Indexed: 01/08/2023] Open
Abstract
The serine/arginine-rich splicing factors (SRs) belong to the serine arginine-rich protein family, which plays an extremely important role in the splicing process of precursor RNA. The SRs recognize the splicing elements on precursor RNA, then recruit and assemble spliceosome to promote or inhibit the occurrence of splicing events. In tumors, aberrant expression of SRs causes abnormal splicing of RNA, contributing to proliferation, migration and apoptosis resistance of tumor cells. Here, we reviewed the vital role of SRs in various tumors and discussed the promise of analyzing mRNA alternative splicing events in tumor. Further, we highlight the challenges and discussed the perspectives for the identification of new potential targets for cancer therapy via SRs family members.
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Affiliation(s)
- Xiang Zheng
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, 541001, China
| | - Qiu Peng
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, Hunan, 410008, China
| | - Lujuan Wang
- Cancer Research Institute, School of Basic Medical Science, Central South University, Changsha, Hunan, 410008, China
| | - Xuemei Zhang
- Department of Pathology, Affiliated Hospital of Guilin Medical University, Guilin, Guangxi, 541001, China
| | - Lili Huang
- Laboratory of Genetics and Metabolism, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region; Guangxi Birth Defects Research and Prevention Institute, Nanning, Guangxi, 530003, China
| | - Jia Wang
- Department of Immunology, Changzhi Medical College, Changzhi, Shanxi, 046000 China
| | - Zailong Qin
- Laboratory of Genetics and Metabolism, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region; Guangxi Birth Defects Research and Prevention Institute, Nanning, Guangxi, 530003, China
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15
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Hartley AV, Lu T. Modulating the modulators: regulation of protein arginine methyltransferases by post-translational modifications. Drug Discov Today 2020; 25:1735-1743. [PMID: 32629172 DOI: 10.1016/j.drudis.2020.06.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 06/14/2020] [Accepted: 06/30/2020] [Indexed: 02/07/2023]
Abstract
The therapeutic potential of targeting protein arginine methyltransferases (PRMTs) is inextricably linked to their key roles in various cellular functions, including splicing, proliferation, cell cycle regulation, differentiation, and DNA damage signaling. Unsurprisingly, the development of inhibitors against these enzymes has become a rapidly expanding research area. However, effective targeting of PRMTs requires a deeper understanding of the mechanistic details behind their regulation at multiple levels, involving those mechanisms that alter their activity, interactions, and localization. Recently, post-translational modifications (PTMs) of PRMTs have emerged as another crucial aspect of this regulation. Here, we review the regulatory role of PTMs in the activity and function of PRMTs, with emphasis on the contribution of these PTMs to pathological states, such as cancer.
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Affiliation(s)
- Antja-Voy Hartley
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA; Department of Medicine, Dana-Farber Cancer Institute, Harvard Medical School, 450 Brookline Avenue, Boston, MA 02215, USA
| | - Tao Lu
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA; Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA; Department of Medical and Molecular Genetics, 975 W. Walnut Street, Indianapolis, IN 46202, USA.
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16
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AMP-activated protein kinase regulates alternative pre-mRNA splicing by phosphorylation of SRSF1. Biochem J 2020; 477:2237-2248. [DOI: 10.1042/bcj20190894] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 05/21/2020] [Accepted: 05/26/2020] [Indexed: 01/23/2023]
Abstract
AMP-activated protein kinase (AMPK) regulates cellular energy homeostasis by inhibiting anabolic processes and activating catabolic processes. Recent studies have demonstrated that metformin, which is an AMPK activator, modifies alternative precursor mRNA (pre-mRNA) splicing. However, no direct substrate of AMPK for alternative pre-mRNA splicing has been reported. In the present study, we identified the splicing factor serine/arginine-rich splicing factor 1 (SRSF1) as a novel AMPK substrate. AMPK directly phosphorylated SRSF1 at Ser133 in an RNA recognition motif. Ser133 phosphorylation suppressed the interaction between SRSF1 and specific RNA sequences without altering the subcellular localization of SRSF1. Moreover, AMPK regulated the SRSF1-mediated alternative pre-mRNA splicing of Ron, which is a macrophage-stimulating protein receptor, by suppressing its interaction with exon 12 of Ron pre-mRNA. The findings of this study revealed that the AMPK-dependent phosphorylation of SRSF1 at Ser133 inhibited the ability of SRSF1 to bind RNA and regulated alternative pre-mRNA splicing.
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17
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Vaklavas C, Blume SW, Grizzle WE. Hallmarks and Determinants of Oncogenic Translation Revealed by Ribosome Profiling in Models of Breast Cancer. Transl Oncol 2020; 13:452-470. [PMID: 31911279 PMCID: PMC6948383 DOI: 10.1016/j.tranon.2019.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/28/2019] [Accepted: 12/01/2019] [Indexed: 12/21/2022] Open
Abstract
Gene expression is extensively and dynamically modulated at the level of translation. How cancer cells prioritize the translation of certain mRNAs over others from a pool of competing mRNAs remains an open question. Here, we analyze translation in cell line models of breast cancer and normal mammary tissue by ribosome profiling. We identify key recurrent themes of oncogenic translation: higher ribosome occupancy, greater variance of translational efficiencies, and preferential translation of transcriptional regulators and signaling proteins in malignant cells as compared with their nonmalignant counterpart. We survey for candidate RNA interacting proteins that could associate with the 5′untranslated regions of the transcripts preferentially translated in breast tumour cells. We identify SRSF1, a prototypic splicing factor, to have a pervasive direct and indirect impact on translation. In a representative estrogen receptor–positive and estrogen receptor–negative cell line, we find that protein synthesis relies heavily on SRSF1. SRSF1 is predominantly intranuclear. Under certain conditions, SRSF1 translocates from the nucleus to the cytoplasm where it associates with MYC and CDK1 mRNAs and upregulates their internal ribosome entry site–mediated translation. Our results point to a synergy between splicing and translation and unveil how certain RNA-binding proteins modulate the translational landscape in breast cancer.
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Affiliation(s)
- Christos Vaklavas
- Department of Medicine, Division of Hematology / Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
| | - Scott W Blume
- Department of Medicine, Division of Hematology / Oncology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - William E Grizzle
- Department of Pathology, O'Neal Comprehensive Cancer Centre, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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18
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Ghemrawi R, Arnold C, Battaglia-Hsu SF, Pourié G, Trinh I, Bassila C, Rashka C, Wiedemann A, Flayac J, Robert A, Dreumont N, Feillet F, Guéant JL, Coelho D. SIRT1 activation rescues the mislocalization of RNA-binding proteins and cognitive defects induced by inherited cobalamin disorders. Metabolism 2019; 101:153992. [PMID: 31672445 DOI: 10.1016/j.metabol.2019.153992] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 09/16/2019] [Accepted: 09/20/2019] [Indexed: 01/01/2023]
Abstract
BACKGROUND The molecular consequences of inborn errors of vitamin B12 or cobalamin metabolism are far from being understood. Moreover, innovative therapeutic strategies are needed for the treatment of neurological outcomes that are usually resistant to conventional treatments. Our previous findings suggest a link between SIRT1, cellular stress and RNA binding proteins (RBP) mislocalization in the pathological mechanisms triggered by impaired vitamin B12 metabolism. OBJECTIVES AND METHODS The goal of this study was to investigate the effects of the pharmacological activation of SIRT1 using SRT1720 on the molecular mechanisms triggered by impaired methionine synthase activity. Experiments were performed in vitro with fibroblasts from patients with the cblG and cblC inherited defects of vitamin B12 metabolism and in vivo with an original transgenic mouse model of methionine synthase deficiency specific to neuronal cells. Subcellular localization of the RBPs HuR, HnRNPA1, RBM10, SRSF1 and Y14 was investigated by immunostaining and confocal microscopy in patient fibroblasts. RBPs methylation and phosphorylation were studied by co-immunoprecipitation and proximity ligation assay. Cognitive performance of the transgenic mice treated with SRT1720 was measured with an aquatic maze. RESULTS Patient fibroblasts with cblC and cblG defects of vitamin B12 metabolism presented with endoplasmic reticulum stress, altered methylation, phosphorylation and subcellular localization of HuR, HnRNPA1 and RBM10, global mRNA mislocalization and increased HnRNPA1-dependent skipping of IRF3 exons. Incubation of fibroblasts with cobalamin, S-adenosyl methionine and okadaic acid rescued the localization of the RBPs and mRNA. The SIRT1 activating compound SRT1720 inhibited ER stress and rescued RBP and mRNA mislocalization and IRF3 splicing. Treatment with this SIRT1 agonist prevented all these hallmarks in patient fibroblasts but it also improved the deficient hippocampo-dependent learning ability of methionine synthase conditional knock-out mice. CONCLUSIONS By unraveling the molecular mechanisms triggered by inborn errors of cbl metabolism associating ER stress, RBP mislocalization and mRNA trafficking, our study opens novel therapeutic perspectives for the treatment of inborn errors of vitamin B12 metabolism.
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Affiliation(s)
- Rose Ghemrawi
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France
| | - Carole Arnold
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Shyue-Fang Battaglia-Hsu
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Grégory Pourié
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Isabelle Trinh
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Christine Bassila
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France
| | - Charif Rashka
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Arnaud Wiedemann
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France; Université de Lorraine, CHRU-Nancy, National Center of Inborn Errors of Metabolism, F-54000 Nancy, France
| | - Justine Flayac
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Aurélie Robert
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - Natacha Dreumont
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France.
| | - François Feillet
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France; Université de Lorraine, CHRU-Nancy, National Center of Inborn Errors of Metabolism, F-54000 Nancy, France.
| | - Jean-Louis Guéant
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France; Université de Lorraine, CHRU-Nancy, National Center of Inborn Errors of Metabolism, F-54000 Nancy, France.
| | - David Coelho
- Université de Lorraine, Inserm, UMRS 1256, NGERE - Nutrition, Genetics, and Environmental Risk Exposure, F-54000 Nancy, France; Université de Lorraine, CHRU-Nancy, National Center of Inborn Errors of Metabolism, F-54000 Nancy, France.
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19
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Hung CS, Lin JC. Alternatively spliced MBNL1 isoforms exhibit differential influence on enhancing brown adipogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2019; 1863:194437. [PMID: 31730826 DOI: 10.1016/j.bbagrm.2019.194437] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 01/15/2023]
Abstract
Browning of white adipocytes (WAs) (also referred as beige cells) was demonstrated to execute thermogenesis by consuming stored lipids as do brown adipocytes (BAs), and this is highly related to metabolic homeostasis. Alternative splicing (AS) constitutes a pivotal mechanism for defining cellular fates and functional specifications. Nevertheless, the impacts of AS regulation on the browning of WAs have not been comprehensively investigated. In this study, we first identified the discriminative expression and splicing profiles of the muscleblind-like 1 (MBNL1) gene in postnatal brown adipose tissues (BATs) compared to those of embryonic BATs. A shift in the MBNL1+ex 5 isoform 7 (MBNL17) to MBNL1-ex 5 isoform 1 (MBNL11) was characterized throughout BAT development or during the in vitro browning of pre-WAs, 3T3-L1 cells. The interplay between MBNL1 and the exonic CCUG motif constitutes an autoregulatory mechanism for excluding MBNL1 exon 5. The simultaneous association of RNA-binding motif protein 4a (RBM4a) with exonic and intronic CU elements collaboratively mediates the skipping of MBNL1 exon 5. Overexpressing the MBNL11 isoform exhibited a more-prominent effect than that of the MBNL17 isoform on programming its own transcripts and beige cell-related splicing events in a CCUG motif-mediated manner. In addition to splicing regulation, overexpression of the MBNL11 and MBNL17 isoforms differentially enhanced beige adipogenic signatures of 3T3-L1 cells. Our findings demonstrated that MBNL1 constitutes an emerging and autoregulatory mechanism involved in development of beige cells.
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Affiliation(s)
- Ching-Sheng Hung
- PhD Program in Medicine Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; Department of Laboratory Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Jung-Chun Lin
- PhD Program in Medicine Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; School of Medical Laboratory Science and Biotechnology, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan.
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20
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PRMT5 methylome profiling uncovers a direct link to splicing regulation in acute myeloid leukemia. Nat Struct Mol Biol 2019; 26:999-1012. [PMID: 31611688 PMCID: PMC6858565 DOI: 10.1038/s41594-019-0313-z] [Citation(s) in RCA: 95] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 09/03/2019] [Indexed: 12/28/2022]
Abstract
Protein arginine methyltransferase 5 (PRMT5) has emerged as a promising cancer drug target, and three PRMT5 inhibitors are currently in clinical trials for multiple malignancies. In this study, we investigated the role of PRMT5 in human acute myeloid leukemia (AML). Using an enzymatic dead version of PRMT5 and a PRMT5-specific inhibitor, we demonstrated the requirement of the catalytic activity of PRMT5 for the survival of AML cells. We then identified PRMT5 substrates using multiplexed quantitative proteomics and investigated their role in the survival of AML cells. We found that the function of the splicing regulator SRSF1 relies on its methylation by PRMT5 and that loss of PRMT5 leads to changes in alternative splicing of multiple essential genes. This explains the requirement of PRMT5 for leukemia cell survival. We show that PRMT5 regulates binding of SRSF1 to mRNAs and proteins and provide potential biomarkers for the treatment response to PRMT5 inhibitors.
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21
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Bauer I, Lechner L, Pidroni A, Petrone AM, Merschak P, Lindner H, Kremser L, Graessle S, Golderer G, Allipour S, Brosch G. Type I and II PRMTs regulate catabolic as well as detoxifying processes in Aspergillus nidulans. Fungal Genet Biol 2019; 129:86-100. [PMID: 31145992 DOI: 10.1016/j.fgb.2019.05.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 05/03/2019] [Accepted: 05/24/2019] [Indexed: 11/28/2022]
Abstract
In filamentous fungi, arginine methylation has been implicated in morphogenesis, mycotoxin biosynthesis, pathogenicity, and stress response although the exact role of this posttranslational modification in these processes remains obscure. Here, we present the first genome-wide transcriptome analysis in filamentous fungi that compared expression levels of genes regulated by type I and type II protein arginine methyltransferases (PRMTs). In Aspergillus nidulans, three conserved type I and II PRMTs are present that catalyze asymmetric or symmetric dimethylation of arginines. We generated a double type I mutant (ΔrmtA/rmtB) and a combined type I and type II mutant (ΔrmtB/rmtC) to perform genome-wide comparison of their effects on gene expression, but also to monitor putative overlapping activities and reciprocal regulations of type I and type II PRMTs in Aspergillus. Our study demonstrates, that rmtA and rmtC as type I and type II representatives act together as repressors of proteins that are secreted into the extracellular region as the majority of up-regulated genes are mainly involved in catabolic pathways that constitute the secretome of Aspergillus. In addition to a strong up-regulation of secretory genes we found a significant enrichment of down-regulated genes involved in processes related to oxidation-reduction, transmembrane transport and secondary metabolite biosynthesis. Strikingly, nearly 50% of down-regulated genes in both double mutants correspond to redox reaction/oxidoreductase processes, a remarkable finding in light of our recently observed oxidative stress phenotypes of ΔrmtA and ΔrmtC. Finally, analysis of nuclear and cytoplasmic extracts for mono-methylated proteins revealed the presence of both, common and specific substrates of RmtA and RmtC. Thus, our data indicate that type I and II PRMTs in Aspergillus seem to co-regulate the same biological processes but also specifically affect other pathways in a non-redundant fashion.
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Affiliation(s)
- Ingo Bauer
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Lukas Lechner
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Angelo Pidroni
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Anna-Maria Petrone
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Petra Merschak
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Herbert Lindner
- Division of Clinical Biochemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Leopold Kremser
- Division of Clinical Biochemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Stefan Graessle
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Georg Golderer
- Division of Biological Chemistry, Medical University of Innsbruck, 6020 Innsbruck, Austria
| | - Shadab Allipour
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
| | - Gerald Brosch
- Division of Molecular Biology, Medical University of Innsbruck, 6020 Innsbruck, Austria.
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22
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Doll F, Steimbach RR, Zumbusch A. Direct Imaging of Protein‐Specific Methylation in Mammalian Cells. Chembiochem 2019; 20:1315-1325. [DOI: 10.1002/cbic.201800787] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Indexed: 01/15/2023]
Affiliation(s)
- Franziska Doll
- Department of ChemistryUniversity of Konstanz Universitätsstrasse 10 78457 Konstanz Germany
- Konstanz Research School Chemical Biology Universitätsstrasse 10 78457 Konstanz Germany
| | - Raphael R. Steimbach
- Department of ChemistryUniversity of Konstanz Universitätsstrasse 10 78457 Konstanz Germany
| | - Andreas Zumbusch
- Department of ChemistryUniversity of Konstanz Universitätsstrasse 10 78457 Konstanz Germany
- Konstanz Research School Chemical Biology Universitätsstrasse 10 78457 Konstanz Germany
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23
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Ran T, Li W, Peng B, Xie B, Lu T, Lu S, Liu W. Virtual Screening with a Structure-Based Pharmacophore Model to Identify Small-Molecule Inhibitors of CARM1. J Chem Inf Model 2019; 59:522-534. [PMID: 30607947 DOI: 10.1021/acs.jcim.8b00610] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
CARM1 (coactivator-associated arginine methyltransferase 1), also known as PRMT4 (protein arginine N-methyltransferase 4), belongs to the protein arginine methyltransferase (PRMT) family, which has emerged as a potential anticancer drug target. To discover new CARM1 inhibitors, we performed virtual screening against the substrate-binding site in CARM1. Structure-based pharmacophore models, which were generated according to three druggable subpockets embedding critical residues for ligand binding, were applied for virtual screening. The importance of the solvent-exposed substrate-binding cavity was highlighted due to significant hydrophobicity. Aided by molecular docking, 15 compounds structurally distinct from known CARM1 inhibitors were selected to evaluate their inhibitory effects on CARM1 methyltransferase activity, which resulted in seven compounds exhibiting micromolar inhibition, with selectivity over other members in the PRMT protein family. Moreover, three of them exhibited potent antiproliferation activities in breast cancer cells. Particularly, compound NO.2 exhibited potent activity both in vitro and in cultured cells, which will serve as a leading hit for developing CARM1 inhibitors with improved efficacy. The virtual screening strategy in this study will be applicable for the discovery of substrate-competitive inhibitors targeting other members in the PRMT protein family.
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Affiliation(s)
- Ting Ran
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research , Xiamen University , Xiamen , Fujian 361102 , China.,Department of Chemical Biology, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen , Fujian 361105 , China
| | - Wenjuan Li
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research , Xiamen University , Xiamen , Fujian 361102 , China
| | - Bingling Peng
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research , Xiamen University , Xiamen , Fujian 361102 , China
| | - Binglan Xie
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research , Xiamen University , Xiamen , Fujian 361102 , China
| | - Tao Lu
- Department of Organic Chemistry, School of Sciences , China Pharmaceutical University , Nanjing , Jiangsu 210009 , China
| | - Shuai Lu
- Department of Organic Chemistry, School of Sciences , China Pharmaceutical University , Nanjing , Jiangsu 210009 , China
| | - Wen Liu
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research , Xiamen University , Xiamen , Fujian 361102 , China.,State Key Laboratory of Cellular Stress Biology , Xiamen University , Xiamen , Fujian 361102 , China
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View from an mRNP: The Roles of SR Proteins in Assembly, Maturation and Turnover. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:83-112. [PMID: 31811631 DOI: 10.1007/978-3-030-31434-7_3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Serine- and arginine-rich proteins (SR proteins) are a family of multitasking RNA-binding proteins (RBPs) that are key determinants of messenger ribonucleoprotein (mRNP) formation, identity and fate. Apart from their essential functions in pre-mRNA splicing, SR proteins display additional pre- and post-splicing activities and connect nuclear and cytoplasmic gene expression machineries. Through changes in their post-translational modifications (PTMs) and their subcellular localization, they provide functional specificity and adjustability to mRNPs. Transcriptome-wide UV crosslinking and immunoprecipitation (CLIP-Seq) studies revealed that individual SR proteins are present in distinct mRNPs and act in specific pairs to regulate different gene expression programmes. Adopting an mRNP-centric viewpoint, we discuss the roles of SR proteins in the assembly, maturation, quality control and turnover of mRNPs and describe the mechanisms by which they integrate external signals, coordinate their multiple tasks and couple subsequent mRNA processing steps.
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25
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Deng J, Julian MH, Lazar IM. Partial enzymatic reactions: A missed opportunity in proteomics research. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2018; 32:2065-2073. [PMID: 30221418 PMCID: PMC6636927 DOI: 10.1002/rcm.8283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Revised: 09/06/2018] [Accepted: 09/10/2018] [Indexed: 05/05/2023]
Abstract
RATIONALE Biological studies are conducted at ever-increasing rates by relying on proteomic workflows. Although data acquisition by mass spectrometry is highly automated and rapid, sample preparation continues to be the bottleneck of developing high-throughput workflows. Enzymatic protein processing, in particular, involves time-consuming protocols that can extend from one day to another. To address this gap, we developed and evaluated simple, in-solution tryptic enzymatic reactions that unfold within a few minutes, and demonstrate the utility of the methodology for the rapid analysis of proteins originating from cancer cell extracts. METHODS Tryptic enzymatic reactions were conducted for 7-60 min, and the results were compared with that of a routine approach conducted for 18 h. No other reaction conditions were changed relative to the 18 h procedure. The reaction products were analyzed by nanospray high-performance liquid chromatography/tandem mass spectrometry (nano-HPLC/MS/MS), and the quality of the products was assessed in terms of peptide/protein identifications, sequence coverage, peptide length, missed-cleavage sites, quality of generated ions, and peptide hydrophilic/hydrophobic properties. RESULTS The results demonstrate that brief, and therefore incomplete, enzymatic processes lead to a large number of peptide fragments that improve protein sequence and proteome coverage, that the tandem mass spectra produced from these peptides are of high quality for reliable protein identifications, and that the physical properties of peptides are prone to supporting the development of alternative multi-dimensional separations and middle-down proteomics analysis strategies. The reproducibility of generating the same peptides within a few minutes of enzymatic digestion was remarkably close to that obtained from 18 h long reactions, and the combined results of short and long reactions increased proteome coverage by ~40%. CONCLUSIONS We demonstrate that partial enzymatic reactions conducted on short time-scales represent a valuable asset to proteomic studies, and propose their implementation either as simple, cost-effective, stand-alone protocols for substantially streamlining the analysis of biological samples, or as complementary protocols, for improving protein sequence and proteome coverage.
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Affiliation(s)
- Jingren Deng
- Department of Biological Sciences, Virginia Tech, 1981 Kraft Drive, Blacksburg, VA 24061, USA
| | - Morgan H. Julian
- Department of Biological Sciences, Virginia Tech, 1981 Kraft Drive, Blacksburg, VA 24061, USA
| | - Iulia M. Lazar
- Department of Biological Sciences, Virginia Tech, 1981 Kraft Drive, Blacksburg, VA 24061, USA
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Xu L, Zhang H, Mei M, Du C, Huang X, Li J, Wang Y, Bao S, Zheng H. Phosphorylation of serine/arginine-rich splicing factor 1 at tyrosine 19 promotes cell proliferation in pediatric acute lymphoblastic leukemia. Cancer Sci 2018; 109:3805-3815. [PMID: 30320932 PMCID: PMC6272096 DOI: 10.1111/cas.13834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 09/21/2018] [Accepted: 10/04/2018] [Indexed: 12/21/2022] Open
Abstract
Serine/arginine‐rich splicing factor 1 (SRSF1) has been linked to various human cancers including pediatric acute lymphoblastic leukemia (ALL). Our previous study has shown that SRSF1 potentially contributes to leukemogenesis; however, its underlying mechanism remains unclear. In this study, leukemic cells were isolated from pediatric ALL bone marrow samples, followed by immunoprecipitation assays and mass spectrometry analysis specific to SRSF1. Subcellular localization of the SRSF1 protein and its mutants were analyzed by immunofluorescence staining. Cell growth, colony formation, cell apoptosis, and the cell cycle were investigated using stable leukemic cell lines generated with lentivirus‐mediated overexpressed WT or mutant plasmids. Cytotoxicity of the Tie2 kinase inhibitor was also evaluated. Our results showed the phosphorylation of SRSF1 at tyrosine 19 (Tyr‐19) was identified in newly diagnosed ALL samples, but not in complete remission or normal control samples. Compared to the SRSF1 WT cells, the missense mutants of the Tyr‐19 phosphorylation affected the subcellular localization of SRSF1. In addition, the Tyr‐19 phosphorylation of SRSF1 also led to increased cell proliferation and enhanced colony‐forming properties by promoting the cell cycle. Remarkably, we further identified the kinase Tie2 as a potential therapeutic target in leukemia cells. In conclusion, we identify for the first time that the phosphorylation state of SRSF1 is linked to different phases in pediatric ALL. The Tyr‐19 phosphorylation of SRSF1 disrupts its subcellular localization and promotes proliferation in leukemia cells by driving cell‐cycle progression. Inhibitors targeting Tie2 kinase that could catalyze Tyr‐19 phosphorylation of SRSF1 offer a promising therapeutic target for treatment of pediatric ALL.
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Affiliation(s)
- Liting Xu
- Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Key Laboratory of Major Diseases in Children, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Han Zhang
- Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Key Laboratory of Major Diseases in Children, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Mei Mei
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Chaohao Du
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Xiahe Huang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Jing Li
- Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Key Laboratory of Major Diseases in Children, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
| | - Yingchun Wang
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Shilai Bao
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Huyong Zheng
- Beijing Key Laboratory of Pediatric Hematology Oncology, National Key Discipline of Pediatrics, Ministry of Education, Key Laboratory of Major Diseases in Children, Ministry of Education, Hematology Oncology Center, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China
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27
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PRMT1 Deficiency in Mouse Juvenile Heart Induces Dilated Cardiomyopathy and Reveals Cryptic Alternative Splicing Products. iScience 2018; 8:200-213. [PMID: 30321814 PMCID: PMC6197527 DOI: 10.1016/j.isci.2018.09.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/25/2018] [Accepted: 09/26/2018] [Indexed: 12/11/2022] Open
Abstract
Protein arginine methyltransferase 1 (PRMT1) catalyzes the asymmetric dimethylation of arginine residues in proteins and methylation of various RNA-binding proteins and is associated with alternative splicing in vitro. Although PRMT1 has essential in vivo roles in embryonic development, CNS development, and skeletal muscle regeneration, the functional importance of PRMT1 in the heart remains to be elucidated. Here, we report that juvenile cardiomyocyte-specific PRMT1-deficient mice develop severe dilated cardiomyopathy and exhibit aberrant cardiac alternative splicing. Furthermore, we identified previously undefined cardiac alternative splicing isoforms of four genes (Asb2, Fbxo40, Nrap, and Eif4a2) in PRMT1-cKO mice and revealed that eIF4A2 protein isoforms translated from alternatively spliced mRNA were differentially ubiquitinated and degraded by the ubiquitin-proteasome system. These findings highlight the essential roles of PRMT1 in cardiac homeostasis and alternative splicing regulation. PRMT1 deficiency in cardiomyocytes causes dilated cardiomyopathy in juvenile mice PRMT1-deficient heart shows abnormal alternative splicing patterns Previously undefined cardiac splicing events are revealed by transcriptome analysis eIF4A2 isoforms are differentially ubiquitinated and degraded
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28
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Kono M, Kurita T, Yasuda S, Kono M, Fujieda Y, Bohgaki T, Katsuyama T, Tsokos GC, Moulton VR, Atsumi T. Decreased Expression of Serine/Arginine-Rich Splicing Factor 1 in T Cells From Patients With Active Systemic Lupus Erythematosus Accounts for Reduced Expression of RasGRP1 and DNA Methyltransferase 1. Arthritis Rheumatol 2018; 70:2046-2056. [PMID: 29905030 DOI: 10.1002/art.40585] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/07/2018] [Indexed: 02/03/2023]
Abstract
OBJECTIVE T cells from systemic lupus erythematosus (SLE) patients have reduced protein levels of RasGRP1, a guanine nucleotide exchange factor for Ras, and increased transcript of alternatively spliced (AS) forms lacking exon 11. Serine/arginine-rich splicing factor 1 (SRSF1) binds pre-messenger RNA (pre-mRNA) to regulate AS forms of several genes, including CD3ζ in SLE T cells. This study was undertaken to assess whether SRSF1 controls the expression of RasGRP1 in T cells from patients with SLE. METHODS We studied T cells from 45 SLE patients and 18 healthy subjects. Expression levels of SRSF1, wild-type (WT) RasGRP1, and DNA methyltransferase 1 (DNMT1) were assessed by quantitative polymerase chain reaction. Direct binding of SRSF1 to exon 11 of RasGRP1 mRNA was evaluated with an oligonucleotide-protein pulldown assay. Healthy T cells and SLE T cells were treated with SRSF1-specific small interfering RNA or SRSF1 expression vector, respectively, and then evaluated for mRNA/protein expression. RESULTS SRSF1 expression levels were significantly lower in T cells from SLE patients compared to those from healthy subjects, and correlated inversely with disease activity and positively with levels of RasGRP1-WT and DNMT1. SRSF1 bound directly to exon 11 of RasGRP1 mRNA. Silencing of SRSF1 in human T cells led to increased ratios of RasGRP1-AS to RasGRP1-WT and decreased levels of RasGRP1 protein, whereas overexpression of SRSF1 in SLE T cells caused recovery of RasGRP1, which in turn induced DNMT1/interleukin-2 expression. CONCLUSION SRSF1 controls the alternative splicing of RasGRP1 and subsequent protein expression. Our findings extend evidence that alternative splicing plays a central role in the aberrant T cell function in patients with SLE by controlling the expression of multiple genes.
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Affiliation(s)
| | | | | | - Michihito Kono
- Hokkaido University, Sapporo, Japan, and Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | | | | | - Takayuki Katsuyama
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - George C Tsokos
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
| | - Vaishali R Moulton
- Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts
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29
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Sun M, Zhang Y, Wang Q, Wu C, Jiang C, Xu JR. The tri-snRNP specific protein FgSnu66 is functionally related to FgPrp4 kinase in Fusarium graminearum. Mol Microbiol 2018; 109:494-508. [PMID: 29923654 DOI: 10.1111/mmi.14005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/08/2018] [Indexed: 11/28/2022]
Abstract
Deletion of Prp4, the only kinase among spliceosome components, is not lethal in Fusarium graminearum but Fgprp4 mutants have severe growth defects and produced spontaneous suppressors. To identify novel suppressor mutations of Fgprp4, we sequenced the genome of suppressor S37 that was normal in growth but only partially recovered for intron splicing and identified a tandem duplication of 9-aa in the tri-snRNP component FgSNU66. Among the 19 additional suppressor strains found to have mutations in FgSNU66 (out of 260 screened), five had the same 9-aa duplication event with S37 and another five had the R477H/C mutation. The rest had nonsense or G-to-D mutations in the C-terminal 27-aa (CT27) region of FgSnu66, which is absent in its yeast ortholog. Truncation of this C-terminal region reduced the interaction of FgSnu66 with FgHub1 but increased its interaction with FgPrp8 and FgPrp6. Five phosphorylation sites were identified in FgSnu66 by phosphoproteomic analysis and the T418A-S420A-S422A mutation was shown to reduce virulence. Overall, our results showed that mutations in FgSNU66 can suppress deletion of Fgprp4, which has not been reported in other organisms, and the C-terminal tail of FgSnu66 plays a role in its interaction with key tri-snRNP components during spliceosome activation.
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Affiliation(s)
- Manli Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Yimei Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Qinhu Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Chunlan Wu
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and NWAFU-Purdue Joint Research Center, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, 712100, China.,Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA
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30
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Pozzi B, Mammi P, Bragado L, Giono LE, Srebrow A. When SUMO met splicing. RNA Biol 2018; 15:689-695. [PMID: 29741121 PMCID: PMC6152442 DOI: 10.1080/15476286.2018.1457936] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2017] [Revised: 02/22/2018] [Accepted: 03/20/2018] [Indexed: 12/12/2022] Open
Abstract
Spliceosomal proteins have been revealed as SUMO conjugation targets. Moreover, we have reported that many of these are in a SUMO-conjugated form when bound to a pre-mRNA substrate during a splicing reaction. We demonstrated that SUMOylation of Prp3 (PRPF3), a component of the U4/U6 di-snRNP, is required for U4/U6•U5 tri-snRNP formation and/or recruitment to active spliceosomes. Expanding upon our previous results, we have shown that the splicing factor SRSF1 stimulates SUMO conjugation to several spliceosomal proteins. Given the relevance of the splicing process, as well as the complex and dynamic nature of its governing machinery, the spliceosome, the molecular mechanisms that modulate its function represent an attractive topic of research. We posit that SUMO conjugation could represent a way of modulating spliceosome assembly and thus, splicing efficiency. How cycles of SUMOylation/de-SUMOylation of spliceosomal proteins become integrated throughout the highly choreographed spliceosomal cycle awaits further investigation.
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Affiliation(s)
- Berta Pozzi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Pablo Mammi
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Laureano Bragado
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Luciana E. Giono
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
| | - Anabella Srebrow
- Instituto de Fisiología, Biología Molecular y Neurociencias (IFIBYNE, UBA- CONICET); Departamento de Fisiología, Biología Molecular y Celular, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires. Ciudad Universitaria, Buenos Aires, Argentina
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31
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Raposo AE, Piller SC. Protein arginine methylation: an emerging regulator of the cell cycle. Cell Div 2018; 13:3. [PMID: 29568320 PMCID: PMC5859524 DOI: 10.1186/s13008-018-0036-2] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 03/13/2018] [Indexed: 12/19/2022] Open
Abstract
Protein arginine methylation is a common post-translational modification where a methyl group is added onto arginine residues of a protein to alter detection by its binding partners or regulate its activity. It is known to be involved in many biological processes, such as regulation of signal transduction, transcription, facilitation of protein–protein interactions, RNA splicing and transport. The enzymes responsible for arginine methylation, protein arginine methyltransferases (PRMTs), have been shown to methylate or associate with important regulatory proteins of the cell cycle and DNA damage repair pathways, such as cyclin D1, p53, p21 and the retinoblastoma protein. Overexpression of PRMTs resulting in aberrant methylation patterns in cancers often correlates with poor recovery prognosis. This indicates that protein arginine methylation is also an important regulator of the cell cycle, and consequently a target for cancer regulation. The effect of protein arginine methylation on the cell cycle and how this emerging key player of cell cycle regulation may be used in therapeutic strategies for cancer are the focus of this review.
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Affiliation(s)
- Anita E Raposo
- School of Science and Health, Western Sydney University, Penrith, NSW 2751 Australia
| | - Sabine C Piller
- School of Science and Health, Western Sydney University, Penrith, NSW 2751 Australia
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32
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Alternative Splicing as a Target for Cancer Treatment. Int J Mol Sci 2018; 19:ijms19020545. [PMID: 29439487 PMCID: PMC5855767 DOI: 10.3390/ijms19020545] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 01/29/2018] [Accepted: 01/29/2018] [Indexed: 02/06/2023] Open
Abstract
Alternative splicing is a key mechanism determinant for gene expression in metazoan. During alternative splicing, non-coding sequences are removed to generate different mature messenger RNAs due to a combination of sequence elements and cellular factors that contribute to splicing regulation. A different combination of splicing sites, exonic or intronic sequences, mutually exclusive exons or retained introns could be selected during alternative splicing to generate different mature mRNAs that could in turn produce distinct protein products. Alternative splicing is the main source of protein diversity responsible for 90% of human gene expression, and it has recently become a hallmark for cancer with a full potential as a prognostic and therapeutic tool. Currently, more than 15,000 alternative splicing events have been associated to different aspects of cancer biology, including cell proliferation and invasion, apoptosis resistance and susceptibility to different chemotherapeutic drugs. Here, we present well established and newly discovered splicing events that occur in different cancer-related genes, their modification by several approaches and the current status of key tools developed to target alternative splicing with diagnostic and therapeutic purposes.
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33
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Brandariz-Núñez A, Zeng F, Lam QN, Jin H. Sbp1 modulates the translation of Pab1 mRNA in a poly(A)- and RGG-dependent manner. RNA (NEW YORK, N.Y.) 2018; 24:43-55. [PMID: 28986506 PMCID: PMC5733569 DOI: 10.1261/rna.062547.117] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 09/29/2017] [Indexed: 05/13/2023]
Abstract
RNA-binding protein Sbp1 facilitates the decapping pathway in mRNA metabolism and inhibits global mRNA translation by an unclear mechanism. Here we report molecular interactions responsible for Sbp1-mediated translation inhibition of mRNA encoding the polyadenosine-binding protein (Pab1), an essential translation factor that stimulates mRNA translation and inhibits mRNA decapping in eukaryotic cells. We demonstrate that the two distal RRMs of Sbp1 bind to the poly(A) sequence in the 5'UTR of the Pab1 mRNA specifically and cooperatively while the central RGG domain of the protein interacts directly with Pab1. Furthermore, methylation of arginines in the RGG domain abolishes the protein-protein interaction and the inhibitory effect of Sbp1 on translation initiation of Pab1 mRNA. Based on these results, the underlying mechanism for Sbp1-specific translational regulation is proposed. The functional differences of Sbp1 and RGG repeats alone on transcript-specific translation were observed, and a comparison of the results suggests the importance of remodeling the 5'UTR by RNA-binding proteins in mRNA translation.
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Affiliation(s)
- Alberto Brandariz-Núñez
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
| | - Fuxing Zeng
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
| | - Quan Ngoc Lam
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
- Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Champaign, Illinois 61801, USA
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Abstract
Many mammalian genes contain poorly spliced introns, resulting in nuclear detention of partially spliced transcripts, which may be exploited to modulate gene expression. In this issue of Cancer Cell, Braun et al. report that the arginine methyltransferase PRMT5 is critical for tumor cell proliferation by regulating numerous detained introns.
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Affiliation(s)
- Xiang-Dong Fu
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0651, USA.
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35
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Botti V, McNicoll F, Steiner MC, Richter FM, Solovyeva A, Wegener M, Schwich OD, Poser I, Zarnack K, Wittig I, Neugebauer KM, Müller-McNicoll M. Cellular differentiation state modulates the mRNA export activity of SR proteins. J Cell Biol 2017; 216:1993-2009. [PMID: 28592444 PMCID: PMC5496613 DOI: 10.1083/jcb.201610051] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2016] [Revised: 03/22/2017] [Accepted: 04/24/2017] [Indexed: 01/22/2023] Open
Abstract
SR proteins connect nuclear pre-mRNA processing to mRNA export and translation. Botti et al. develop a quantitative nucleocytoplasmic shuttling assay and show that SR proteins are differentially modified and active in differentiated and pluripotent cells. SR proteins function in nuclear pre-mRNA processing, mRNA export, and translation. To investigate their cellular dynamics, we developed a quantitative assay, which detects differences in nucleocytoplasmic shuttling among seven canonical SR protein family members. As expected, SRSF2 and SRSF5 shuttle poorly in HeLa cells but surprisingly display considerable shuttling in pluripotent murine P19 cells. Combining individual-resolution cross-linking and immunoprecipitation (iCLIP) and mass spectrometry, we show that elevated arginine methylation of SRSF5 and lower phosphorylation levels of cobound SRSF2 enhance shuttling of SRSF5 in P19 cells by modulating protein–protein and protein–RNA interactions. Moreover, SRSF5 is bound to pluripotency-specific transcripts such as Lin28a and Pou5f1/Oct4 in the cytoplasm. SRSF5 depletion reduces and overexpression increases their cytoplasmic mRNA levels, suggesting that enhanced mRNA export by SRSF5 is required for the expression of pluripotency factors. Remarkably, neural differentiation of P19 cells leads to dramatically reduced SRSF5 shuttling. Our findings indicate that posttranslational modification of SR proteins underlies the regulation of their mRNA export activities and distinguishes pluripotent from differentiated cells.
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Affiliation(s)
- Valentina Botti
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - François McNicoll
- Cluster of Excellence Macromolecular Complexes, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Michaela C Steiner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Florian M Richter
- Functional Proteomics Group, Institute for Biochemistry I, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Anfisa Solovyeva
- Cluster of Excellence Macromolecular Complexes, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Marius Wegener
- Cluster of Excellence Macromolecular Complexes, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Oliver D Schwich
- Cluster of Excellence Macromolecular Complexes, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany.,Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences, Frankfurt am Main, Germany
| | - Ilka Wittig
- Functional Proteomics Group, Institute for Biochemistry I, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Karla M Neugebauer
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT
| | - Michaela Müller-McNicoll
- Cluster of Excellence Macromolecular Complexes, Institute of Cell Biology and Neuroscience, Goethe University Frankfurt, Frankfurt am Main, Germany
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36
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Muddukrishna B, Jackson CA, Yu MC. Protein arginine methylation of Npl3 promotes splicing of the SUS1 intron harboring non-consensus 5' splice site and branch site. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:730-739. [PMID: 28392442 DOI: 10.1016/j.bbagrm.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Revised: 03/20/2017] [Accepted: 04/04/2017] [Indexed: 11/18/2022]
Abstract
Protein arginine methylation occurs on spliceosomal components and spliceosome-associated proteins, but how this modification contributes to their function in pre-mRNA splicing remains sparse. Here we provide evidence that protein arginine methylation of the yeast SR-/hnRNP-like protein Npl3 plays a role in facilitating efficient splicing of the SUS1 intron that harbors a non-consensus 5' splice site and branch site. In yeast cells lacking the major protein arginine methyltransferase HMT1, we observed a change in the co-transcriptional recruitment of the U1 snRNP subunit Snp1 and Npl3 to pre-mRNAs harboring both consensus (ECM33 and ASC1) and non-consensus (SUS1) 5' splice site and branch site. Using an Npl3 mutant that phenocopies wild-type Npl3 when expressed in Δhmt1 cells, we showed that the arginine methylation of Npl3 is responsible for this. Examination of pre-mRNA splicing efficiency in these mutants reveals the requirement of Npl3 methylation for the efficient splicing of SUS1 intron 1, but not of ECM33 or ASC1. Changing the 5' splice site and branch site in SUS1 intron 1 to the consensus form restored splicing efficiency in an Hmt1-independent manner. Results from biochemical studies show that methylation of Npl3 promotes its optimal association with the U1 snRNP through its association with the U1 snRNP subunit Mud1. Based on these data, we propose a model in which Hmt1, via arginine methylation of Npl3, facilitates U1 snRNP engagement with the pre-mRNA to promote usage of non-consensus splice sites by the splicing machinery.
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Affiliation(s)
- Bhavana Muddukrishna
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Christopher A Jackson
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States
| | - Michael C Yu
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, NY, United States.
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Wall ML, Lewis SM. Methylarginines within the RGG-Motif Region of hnRNP A1 Affect Its IRES Trans-Acting Factor Activity and Are Required for hnRNP A1 Stress Granule Localization and Formation. J Mol Biol 2016; 429:295-307. [PMID: 27979648 DOI: 10.1016/j.jmb.2016.12.011] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/22/2016] [Accepted: 12/08/2016] [Indexed: 12/30/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) is a stress granule-associated RNA-binding protein that plays a role in apoptosis and cellular stress recovery. HnRNP A1 is a major non-histone target of protein arginine methyltransferase 1, which asymmetrically dimethylates hnRNP A1 at several key arginine residues within its arginine-glycine-glycine (RGG)-motif region. Although arginine methylation is known to regulate general RNA binding of hnRNP A1 in vitro, the functional role of arginine methylation in hnRNP A1 cytoplasmic activity is unknown. To test the impact of key methylarginine residues on hnRNP A1 cytoplasmic activity and stress granule association, cytoplasmically restricted Flag-tagged mutants of hnRNP A1 were generated in which key methylarginine residues within the RGG-motif region were changed to either lysine or alanine. Lysine substitution, which mimics unmethylated arginine, resulted in a 40% increase in internal ribosome entry site trans-acting factor (ITAF) activity and the protein readily associates with stress granules. Alanine substitution resulted in a loss of ITAF activity and reduced mRNA binding. The alanine mutant also displays reduced stress granule association and suppresses stress granule formation. Our data suggest that arginine residues within the RGG-motif region are critical for hnRNP A1 cytoplasmic activities and that endogenous asymmetric dimethylation of the RGG-motif region suppresses hnRNP A1 ITAF activity in cells. Our findings indicate that methylarginine residues within the RGG-motif region of hnRNP A1 are important for its cytoplasmic activities and that hypomethylation and/or mutation of the RGG-motif region may contribute to the role of hnRNP A1 in diseases such as cancer.
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Affiliation(s)
- Michael L Wall
- Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada
| | - Stephen M Lewis
- Atlantic Cancer Research Institute, Moncton, New Brunswick, Canada; Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada; Department of Biology, University of New Brunswick, Saint John, New Brunswick, Canada; Department of Chemistry & Biochemistry, Université de Moncton, Moncton, New Brunswick, Canada.
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38
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Cura V, Marechal N, Troffer-Charlier N, Strub JM, van Haren MJ, Martin NI, Cianférani S, Bonnefond L, Cavarelli J. Structural studies of protein arginine methyltransferase 2 reveal its interactions with potential substrates and inhibitors. FEBS J 2016; 284:77-96. [PMID: 27879050 DOI: 10.1111/febs.13953] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 09/27/2016] [Accepted: 11/02/2016] [Indexed: 12/18/2022]
Abstract
PRMT2 is the less-characterized member of the protein arginine methyltransferase family in terms of structure, activity, and cellular functions. PRMT2 is a modular protein containing a catalytic Ado-Met-binding domain and unique Src homology 3 domain that binds proteins with proline-rich motifs. PRMT2 is involved in a variety of cellular processes and has diverse roles in transcriptional regulation through different mechanisms depending on its binding partners. PRMT2 has been demonstrated to have weak methyltransferase activity on a histone H4 substrate, but its optimal substrates have not yet been identified. To obtain insights into the function and activity of PRMT2, we solve several crystal structures of PRMT2 from two homologs (zebrafish and mouse) in complex with either the methylation product S-adenosyl-L-homocysteine or other compounds including the first synthetic PRMT2 inhibitor (Cp1) studied so far. We reveal that the N-terminal-containing SH3 module is disordered in the full-length crystal structures, and highlights idiosyncratic features of the PRMT2 active site. We identify a new nonhistone protein substrate belonging to the serine-/arginine-rich protein family which interacts with PRMT2 and we characterize six methylation sites by mass spectrometry. To better understand structural basis for Cp1 binding, we also solve the structure of the complex PRMT4:Cp1. We compare the inhibitor-protein interactions occurring in the PRMT2 and PRMT4 complex crystal structures and show that this compound inhibits efficiently PRMT2. These results are a first step toward a better understanding of PRMT2 substrate recognition and may accelerate the development of structure-based drug design of PRMT2 inhibitors. DATABASE All coordinates and structure factors have been deposited in the Protein Data Bank: zPRMT21-408 -SFG = 5g02; zPRMT273-408 -SAH = 5fub; mPRMT21-445 -SAH = 5ful; mPRMT21-445 -Cp1 = 5fwa, mCARM1130-487 -Cp1 = 5k8v.
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Affiliation(s)
- Vincent Cura
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U596, Université de Strasbourg, Illkirch, France
| | - Nils Marechal
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U596, Université de Strasbourg, Illkirch, France
| | - Nathalie Troffer-Charlier
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U596, Université de Strasbourg, Illkirch, France
| | - Jean-Marc Strub
- BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, UMR7178, Université de Strasbourg, France
| | - Matthijs J van Haren
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | - Nathaniel I Martin
- Department of Chemical Biology and Drug Discovery, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, The Netherlands
| | - Sarah Cianférani
- BioOrganic Mass Spectrometry Laboratory (LSMBO), IPHC, UMR7178, Université de Strasbourg, France
| | - Luc Bonnefond
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U596, Université de Strasbourg, Illkirch, France
| | - Jean Cavarelli
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR7104, INSERM U596, Université de Strasbourg, Illkirch, France
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Uleri E, Ibba G, Piu C, Caocci M, Leoni S, Arru G, Serra C, Sechi G, Dolei A. JC polyomavirus expression and bell-shaped regulation of its SF2/ASF suppressor during the follow-up of multiple sclerosis patients treated with natalizumab. J Neurovirol 2016; 23:226-238. [PMID: 27812788 DOI: 10.1007/s13365-016-0492-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/19/2016] [Accepted: 10/10/2016] [Indexed: 12/14/2022]
Abstract
Natalizumab is effective against multiple sclerosis (MS), but is associated with progressive multifocal leukoencephalopathy (PML), fatal disease caused by the JCV polyomavirus. The SF2/ASF (splicing factor2/alternative splicing factor) inhibits JCV in glial cells. We wondered about SF2/ASF modulation in the blood of natalizumab-treated patients and if this could influence JCV reactivation. Therefore, we performed a longitudinal study of MS patients under natalizumab, in comparison to patients under fingolimod and to healthy blood donors. Blood samples were collected at time intervals. The expression of SF2/ASF and the presence and expression of JCV in PBMC were analyzed. A bell-shaped regulation of SF2/ASF was observed in patients treated with natalizumab, increased in the first year of therapy, and reduced in the second one, while slightly changed, if any, in patients under fingolimod. Notably, SF2/ASF was up-regulated, during the first year, only in JCV DNA-positive patients, or with high anti-JCV antibody response; the expression of the JCV T-Ag protein in circulating B cells was inversely related to SF2/ASF protein expression. The SF2/ASF reduction, parallel to JCV activation, during the second year of therapy with natalizumab, but not with fingolimod, may help explain the increased risk of PML after the second year of treatment with natalizumab, but not with fingolimod. We propose that SF2/ASF has a protective role against JCV reactivation in MS patients. This study suggests new markers of disease behavior and, possibly, help in re-evaluations of therapy protocols.
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Affiliation(s)
- Elena Uleri
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy
| | - Gabriele Ibba
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy
| | - Claudia Piu
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy
| | - Maurizio Caocci
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy
| | - Stefania Leoni
- Department of Clinical and Experimental Medicine, University of Sassari, Viale San Pietro 8, I-07100, Sassari, Italy
| | - Giannina Arru
- Department of Clinical and Experimental Medicine, University of Sassari, Viale San Pietro 8, I-07100, Sassari, Italy
| | - Caterina Serra
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy
| | - GianPietro Sechi
- Department of Clinical and Experimental Medicine, University of Sassari, Viale San Pietro 8, I-07100, Sassari, Italy
| | - Antonina Dolei
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43B, I-07100, Sassari, Italy.
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Sanchez G, Bondy-Chorney E, Laframboise J, Paris G, Didillon A, Jasmin BJ, Côté J. A novel role for CARM1 in promoting nonsense-mediated mRNA decay: potential implications for spinal muscular atrophy. Nucleic Acids Res 2015; 44:2661-76. [PMID: 26656492 PMCID: PMC4824080 DOI: 10.1093/nar/gkv1334] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 11/16/2015] [Indexed: 01/09/2023] Open
Abstract
Loss of ‘Survival of Motor Neurons’ (SMN) leads to spinal muscular atrophy (SMA), a disease characterized by degeneration of spinal cord alpha motor neurons, resulting in muscle weakness, paralysis and death during early childhood. SMN is required for assembly of the core splicing machinery, and splicing defects were documented in SMA. We previously uncovered that Coactivator-Associated Methyltransferase-1 (CARM1) is abnormally up-regulated in SMA, leading to mis-regulation of a number of transcriptional and alternative splicing events. We report here that CARM1 can promote decay of a premature terminating codon (PTC)-containing mRNA reporter, suggesting it can act as a mediator of nonsense-mediated mRNA decay (NMD). Interestingly, this pathway, while originally perceived as solely a surveillance mechanism preventing expression of potentially detrimental proteins, is now emerging as a highly regulated RNA decay pathway also acting on a subset of normal mRNAs. We further show that CARM1 associates with major NMD factor UPF1 and promotes its occupancy on PTC-containing transcripts. Finally, we identify a specific subset of NMD targets that are dependent on CARM1 for degradation and that are also misregulated in SMA, potentially adding exacerbated targeting of PTC-containing mRNAs to the already complex array of molecular defects associated with this disease.
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Affiliation(s)
- Gabriel Sanchez
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Emma Bondy-Chorney
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Janik Laframboise
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Geneviève Paris
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Andréanne Didillon
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Bernard J Jasmin
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Jocelyn Côté
- Centre for Neuromuscular Disease, Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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Zhang L, Tran NT, Su H, Wang R, Lu Y, Tang H, Aoyagi S, Guo A, Khodadadi-Jamayran A, Zhou D, Qian K, Hricik T, Côté J, Han X, Zhou W, Laha S, Abdel-Wahab O, Levine RL, Raffel G, Liu Y, Chen D, Li H, Townes T, Wang H, Deng H, Zheng YG, Leslie C, Luo M, Zhao X. Cross-talk between PRMT1-mediated methylation and ubiquitylation on RBM15 controls RNA splicing. eLife 2015; 4:07938. [PMID: 26575292 PMCID: PMC4775220 DOI: 10.7554/elife.07938] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Accepted: 11/16/2015] [Indexed: 12/24/2022] Open
Abstract
RBM15, an RNA binding protein, determines cell-fate specification of many tissues including blood. We demonstrate that RBM15 is methylated by protein arginine methyltransferase 1 (PRMT1) at residue R578, leading to its degradation via ubiquitylation by an E3 ligase (CNOT4). Overexpression of PRMT1 in acute megakaryocytic leukemia cell lines blocks megakaryocyte terminal differentiation by downregulation of RBM15 protein level. Restoring RBM15 protein level rescues megakaryocyte terminal differentiation blocked by PRMT1 overexpression. At the molecular level, RBM15 binds to pre-messenger RNA intronic regions of genes important for megakaryopoiesis such as GATA1, RUNX1, TAL1 and c-MPL. Furthermore, preferential binding of RBM15 to specific intronic regions recruits the splicing factor SF3B1 to the same sites for alternative splicing. Therefore, PRMT1 regulates alternative RNA splicing via reducing RBM15 protein concentration. Targeting PRMT1 may be a curative therapy to restore megakaryocyte differentiation for acute megakaryocytic leukemia. DOI:http://dx.doi.org/10.7554/eLife.07938.001 The many different cell types in an adult animal all develop from a single fertilized egg. The development of cells into more specialized cell types is called ‘differentiation’. Proteins and other molecules from both inside and outside of the cells regulate the differentiation process. RNA is a molecule that is similar to DNA, and performs several important roles inside cells. Perhaps most importantly, RNA molecules act as messengers and carry genetic instructions during gene expression. RBM15 is an RNA-binding protein that is found throughout nature, and is involved in a number of developmental processes. Previous research has linked the incorrect control of RBM15 with an increased risk of certain cancers, including megakaryocytic leukemia. However, it is not clear what role RNA-binding proteins such as RBM15 play during differentiation. Now, Zhang, Tran, Su et al. have investigated the role of RBM15 during the development of large cells found in human bone marrow (called megakaryocytes). First, the experiments demonstrated that an enzyme called PRMT1 modifies RBM15. This enzyme adds a chemical mark called a methyl group at a specific site (an arginine amino acid) on the RNA-binding protein. Next, Zhang, Tran, Su et al. showed that the addition of this methyl group earmarks RBM15 for destruction. This means that an increase in PRMT1 levels reduces the amount of RBM15 in cells, while decreases in PRMT1 have the opposite effect. Further experiments showed that RBM15 normally processes the RNA messengers that carry the genetic instructions needed for the differentiation of bone marrow cells. An excess of PRMT1 enzyme leads to a lack of this RNA-binding protein. This in turn interferes with the differentiation process, and can contribute to the development of cancers such as megakaryocytic leukemia. Future work will therefore explore whether targeting PRMT1 with drugs could represent an effective treatment for these kinds of cancers. DOI:http://dx.doi.org/10.7554/eLife.07938.002
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Affiliation(s)
- Li Zhang
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Ngoc-Tung Tran
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Hairui Su
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Rui Wang
- Program of Molecular Pharmacology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Yuheng Lu
- Computational Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Haiping Tang
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Sayura Aoyagi
- Cell Signaling Technology, Inc., Danvers, United States
| | - Ailan Guo
- Cell Signaling Technology, Inc., Danvers, United States
| | - Alireza Khodadadi-Jamayran
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Dewang Zhou
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Kun Qian
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia, Athens, United States
| | - Todd Hricik
- Human Oncology and Pathogenesis Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Canada
| | - Xiaosi Han
- Department of Neurology, Comprehensive Cancer Center, The University of Alabama at Birmingham, Birmingham, United States
| | - Wenping Zhou
- Department of Internal Medicine, Zhengzhou - Henan Cancer Hospital, Zhengzhou, China
| | - Suparna Laha
- Division of Hematology and Oncology, University of Massachusetts Medical School, Worcester, United States
| | - Omar Abdel-Wahab
- Human Oncology and Pathogenesis Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Ross L Levine
- Human Oncology and Pathogenesis Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Glen Raffel
- Division of Hematology and Oncology, University of Massachusetts Medical School, Worcester, United States
| | - Yanyan Liu
- Department of Internal Medicine, Zhengzhou - Henan Cancer Hospital, Zhengzhou, China
| | - Dongquan Chen
- Division of Preventive Medicine, The University of Alabama at Birmingham, Birmingham, United States
| | - Haitao Li
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Tim Townes
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Hengbin Wang
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
| | - Haiteng Deng
- School of Life Sciences, Tsinghua University, Beijing, China
| | - Y George Zheng
- Department of Pharmaceutical and Biomedical Sciences, The University of Georgia, Athens, United States
| | - Christina Leslie
- Computational Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Minkui Luo
- Program of Molecular Pharmacology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, United States
| | - Xinyang Zhao
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, The University of Alabama at Birmingham, Birmingham, United States
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42
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Sylvestersen KB, Nielsen ML. Large‐Scale Identification of the Arginine Methylome by Mass Spectrometry. ACTA ACUST UNITED AC 2015; 82:24.7.1-24.7.17. [DOI: 10.1002/0471140864.ps2407s82] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Kathrine B. Sylvestersen
- Department of Proteomics The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences Copenhagen Denmark
| | - Michael L. Nielsen
- Department of Proteomics The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences Copenhagen Denmark
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43
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Posttranscriptional Regulation of Splicing Factor SRSF1 and Its Role in Cancer Cell Biology. BIOMED RESEARCH INTERNATIONAL 2015; 2015:287048. [PMID: 26273603 PMCID: PMC4529898 DOI: 10.1155/2015/287048] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 12/16/2014] [Indexed: 01/23/2023]
Abstract
Over the past decade, alternative splicing has been progressively recognized as a major mechanism regulating gene expression patterns in different tissues and disease states through the generation of multiple mRNAs from the same gene transcript. This process requires the joining of selected exons or usage of different pairs of splice sites and is regulated by gene-specific combinations of RNA-binding proteins. One archetypical splicing regulator is SRSF1, for which we review the molecular mechanisms and posttranscriptional modifications involved in its life cycle. These include alternative splicing of SRSF1 itself, regulatory protein phosphorylation events, and the role of nuclear versus cytoplasmic SRSF1 localization. In addition, we resume current knowledge on deregulated SRSF1 expression in tumors and describe SRSF1-regulated alternative transcripts with functional consequences for cancer cell biology at different stages of tumor development.
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44
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Lott K, Mukhopadhyay S, Li J, Wang J, Yao J, Sun Y, Qu J, Read LK. Arginine methylation of DRBD18 differentially impacts its opposing effects on the trypanosome transcriptome. Nucleic Acids Res 2015; 43:5501-23. [PMID: 25940618 PMCID: PMC4477658 DOI: 10.1093/nar/gkv428] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/22/2015] [Indexed: 12/30/2022] Open
Abstract
Arginine methylation is a posttranslational modification that impacts wide-ranging cellular functions, including transcription, mRNA splicing and translation. RNA binding proteins (RBPs) represent one of the largest classes of arginine methylated proteins in both mammals and the early diverging parasitic protozoan, Trypanosoma brucei. Here, we report the effects of arginine methylation on the functions of the essential and previously uncharacterized T. brucei RBP, DRBD18. RNAseq analysis shows that DRBD18 depletion causes extensive rearrangement of the T. brucei transcriptome, with increases and decreases in hundreds of mRNAs. DRBD18 contains three methylated arginines, and we used complementation of DRBD18 knockdown cells with methylmimic or hypomethylated DRBD18 to assess the functions of these methylmarks. Methylmimic and hypomethylated DRBD18 associate with different ribonucleoprotein complexes. These altered macromolecular interactions translate into differential impacts on the T. brucei transcriptome. Methylmimic DRBD18 preferentially stabilizes target RNAs, while hypomethylated DRBD18 is more efficient at destabilizing RNA. The protein arginine methyltransferase, TbPRMT1, interacts with DRBD18 and knockdown of TbPRMT1 recapitulates the effects of hypomethylated DRBD18 on mRNA levels. Together, these data support a model in which arginine methylation acts as a switch that regulates T. brucei gene expression.
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Affiliation(s)
- Kaylen Lott
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Shreya Mukhopadhyay
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jun Li
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jie Wang
- Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jin Yao
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Yijun Sun
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Jun Qu
- Department of Pharmaceutical Sciences, University at Buffalo, Buffalo, NY, USA
| | - Laurie K Read
- Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, USA
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Kaehler C, Guenther A, Uhlich A, Krobitsch S. PRMT1-mediated arginine methylation controls ATXN2L localization. Exp Cell Res 2015; 334:114-25. [PMID: 25748791 DOI: 10.1016/j.yexcr.2015.02.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 01/02/2023]
Abstract
Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine-glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory.
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Affiliation(s)
- Christian Kaehler
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anika Guenther
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anja Uhlich
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Sylvia Krobitsch
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
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Kavunja HW, Voss PG, Wang JL, Huang X. Identification of Lectins from Metastatic Cancer Cells through Magnetic Glyconanoparticles. Isr J Chem 2015; 55:423-436. [PMID: 27110035 PMCID: PMC4838199 DOI: 10.1002/ijch.201400156] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Cancer cells can have characteristic carbohydrate binding properties. Previously, it was shown that a highly metastatic melanoma cell line B16F10 bound to galacto-side-functionalized nanoparticles much stronger than the corresponding less metastatic B16F1 cells. To better understand the carbohydrate binding properties of cancer cells, herein, we report the isolation and characterization of endogenous galactose binding proteins from B16F10 cells using magnetic glyconanoparticles. The galactose-coated magnetic glyconanoparticles could bind with lectins present in the cells and be isolated through magnet-mediated separation. Through Western blot and mass spectrometry, the arginine/serine rich splicing factor Sfrs1 was identified as a galactose-selective endogenous lectin, overexpressed in B16F10 cells, compared with B16F1 cells. In addition, galactin-3 was found in higher amounts in B16F10 cells. Finally, the glyconanoparticles exhibited a superior efficiency in lectin isolation, from both protein mixtures and live cells, than the corresponding more traditional microparticles functionalized with carbohydrates. Thus, the magnetic glyconanoparticles present a useful tool for discovery of endogenous lectins, as well as binding partners of lectins, without prior knowledge of protein identities.
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Affiliation(s)
- Herbert W. Kavunja
- Department of Chemistry, Chemistry Building, Room 426, 578 S. Shaw Lane, Michigan State University, East Lansing, MI 48824 (USA)
| | - Patricia G. Voss
- Department of Biochemistry and Molecular Biology, Biochemistry Building, Room 402, 603 Wilson Road, Michigan State University, East Lansing, MI 48824 (USA)
| | - John L. Wang
- Department of Biochemistry and Molecular Biology, Biochemistry Building, Room 402, 603 Wilson Road, Michigan State University, East Lansing, MI 48824 (USA)
| | - Xuefei Huang
- Department of Chemistry, Chemistry Building, Room 426, 578 S. Shaw Lane, Michigan State University, East Lansing, MI 48824 (USA)
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Araki S, Dairiki R, Nakayama Y, Murai A, Miyashita R, Iwatani M, Nomura T, Nakanishi O. Inhibitors of CLK protein kinases suppress cell growth and induce apoptosis by modulating pre-mRNA splicing. PLoS One 2015; 10:e0116929. [PMID: 25581376 PMCID: PMC4291223 DOI: 10.1371/journal.pone.0116929] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/16/2014] [Indexed: 12/22/2022] Open
Abstract
Accumulating evidence has demonstrated the importance of alternative splicing in various physiological processes, including the development of different diseases. CDC-like kinases (CLKs) and serine-arginine protein kinases (SRPKs) are components of the splicing machinery that are crucial for exon selection. The discovery of small molecule inhibitors against these kinases is of significant value, not only to delineate the molecular mechanisms of splicing, but also to identify potential therapeutic opportunities. Here we describe a series of small molecules that inhibit CLKs and SRPKs and thereby modulate pre-mRNA splicing. Treatment with these small molecules (Cpd-1, Cpd-2, or Cpd-3) significantly reduced the levels of endogenous phosphorylated SR proteins and caused enlargement of nuclear speckles in MDA-MB-468 cells. Additionally, the compounds resulted in splicing alterations of RPS6KB1 (S6K), and subsequent depletion of S6K protein. Interestingly, the activity of compounds selective for CLKs was well correlated with the activity for modulating S6K splicing as well as growth inhibition of cancer cells. A comprehensive mRNA sequencing approach revealed that the inhibitors induced splicing alterations and protein depletion for multiple genes, including those involved in growth and survival pathways such as S6K, EGFR, EIF3D, and PARP. Fluorescence pulse-chase labeling analyses demonstrated that isoforms with premature termination codons generated after treatment with the CLK inhibitors were degraded much faster than canonical mRNAs. Taken together, these results suggest that CLK inhibitors exhibit growth suppression and apoptosis induction through splicing alterations in genes involved in growth and survival. These small molecule inhibitors may be valuable tools for elucidating the molecular machinery of splicing and for the potential development of a novel class of antitumor agents.
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Affiliation(s)
- Shinsuke Araki
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Ryo Dairiki
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Yusuke Nakayama
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Aiko Murai
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Risa Miyashita
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Misa Iwatani
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Toshiyuki Nomura
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
| | - Osamu Nakanishi
- Pharmaceutical Research Division, Takeda Pharmaceutical Company Limited, Kanagawa, Japan
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48
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Howard JM, Sanford JR. The RNAissance family: SR proteins as multifaceted regulators of gene expression. WILEY INTERDISCIPLINARY REVIEWS-RNA 2014; 6:93-110. [PMID: 25155147 DOI: 10.1002/wrna.1260] [Citation(s) in RCA: 158] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Revised: 07/09/2014] [Accepted: 07/14/2014] [Indexed: 12/29/2022]
Abstract
Serine and arginine-rich (SR) proteins play multiple roles in the eukaryotic gene expression pathway. Initially described as constitutive and alternative splicing factors, now it is clear that SR proteins are key determinants of exon identity and function as molecular adaptors, linking the pre-messenger RNA (pre-mRNA) to the splicing machinery. In addition, now SR proteins are implicated in many aspects of mRNA and noncoding RNA (ncRNA) processing well beyond splicing. These unexpected roles, including RNA transcription, export, translation, and decay, may prove to be the rule rather than the exception. To simply define, this family of RNA-binding proteins as splicing factors belies the broader roles of SR proteins in post-transcriptional gene expression.
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Affiliation(s)
- Jonathan M Howard
- Department of Molecular, Cellular and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA, USA
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Das S, Krainer AR. Emerging functions of SRSF1, splicing factor and oncoprotein, in RNA metabolism and cancer. Mol Cancer Res 2014; 12:1195-204. [PMID: 24807918 DOI: 10.1158/1541-7786.mcr-14-0131] [Citation(s) in RCA: 194] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Serine/Arginine Splicing Factor 1 (SRSF1) is the archetype member of the SR protein family of splicing regulators. Since its discovery over two decades ago, SRSF1 has been repeatedly surprising and intriguing investigators by the plethora of complex biologic pathways it regulates. These include several key aspects of mRNA metabolism, such as mRNA splicing, stability, and translation, as well as other mRNA-independent processes, such as miRNA processing, protein sumoylation, and the nucleolar stress response. In this review, the structural features of SRSF1 are discussed as they relate to the intricate mechanism of splicing and the multiplicity of functions it performs. Similarly, a list of relevant alternatively spliced transcripts and SRSF1 interacting proteins is provided. Finally, emphasis is given to the deleterious consequences of overexpression of the SRSF1 proto-oncogene in human cancers, and the complex mechanisms and pathways underlying SRSF1-mediated transformation. The accumulated knowledge about SRSF1 provides critical insight into the integral role it plays in maintaining cellular homeostasis and suggests new targets for anticancer therapy. Mol Cancer Res; 12(9); 1195-204. ©2014 AACR.
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Affiliation(s)
- Shipra Das
- Cold Spring Harbor Laboratory, Cold Spring Harbor, New York
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50
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Biamonti G, Catillo M, Pignataro D, Montecucco A, Ghigna C. The alternative splicing side of cancer. Semin Cell Dev Biol 2014; 32:30-6. [PMID: 24657195 DOI: 10.1016/j.semcdb.2014.03.016] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 03/11/2014] [Indexed: 12/22/2022]
Abstract
Alternative splicing emerges as a potent and pervasive mechanism of gene expression regulation that expands the coding capacity of the genome and forms an intermediate layer of regulation between transcriptional and post-translational networks. Indeed, alternative splicing occupies a pivotal position in developmental programs and in the cell response to external and internal stimuli. Not surprisingly, therefore, its deregulation frequently leads to human disease. In this review we provide an updated overview of the impact of alternative splicing on tumorigenesis. Moreover, we discuss the intricacy of the reciprocal interactions between alternative splicing programs and signal transduction pathways, which appear to be crucially linked to cancer progression in response to the tumor microenvironment. Finally, we focus on the recently described interplay between splicing and chromatin organization which is expected to shed new lights into gene expression regulation in normal and cancer cells.
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Affiliation(s)
- Giuseppe Biamonti
- Istituto di Genetica Molecolare - CNR, Via Abbiategrasso 207, 27011 Pavia, Italy.
| | - Morena Catillo
- Istituto di Genetica Molecolare - CNR, Via Abbiategrasso 207, 27011 Pavia, Italy
| | - Daniela Pignataro
- Istituto di Genetica Molecolare - CNR, Via Abbiategrasso 207, 27011 Pavia, Italy
| | | | - Claudia Ghigna
- Istituto di Genetica Molecolare - CNR, Via Abbiategrasso 207, 27011 Pavia, Italy
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