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Fuentes Y, Olguín V, López-Ulloa B, Mendonça D, Ramos H, Abdalla A, Guajardo-Contreras G, Niu M, Rojas-Araya B, Mouland A, López-Lastra M. Heterogeneous nuclear ribonucleoprotein K promotes cap-independent translation initiation of retroviral mRNAs. Nucleic Acids Res 2024; 52:2625-2647. [PMID: 38165048 PMCID: PMC10954487 DOI: 10.1093/nar/gkad1221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 12/07/2023] [Accepted: 12/15/2023] [Indexed: 01/03/2024] Open
Abstract
Translation initiation of the human immunodeficiency virus-type 1 (HIV-1) genomic mRNA (vRNA) is cap-dependent or mediated by an internal ribosome entry site (IRES). The HIV-1 IRES requires IRES-transacting factors (ITAFs) for function. In this study, we evaluated the role of the heterogeneous nuclear ribonucleoprotein K (hnRNPK) as a potential ITAF for the HIV-1 IRES. In HIV-1-expressing cells, the depletion of hnRNPK reduced HIV-1 vRNA translation. Furthermore, both the depletion and overexpression of hnRNPK modulated HIV-1 IRES activity. Phosphorylations and protein arginine methyltransferase 1 (PRMT1)-induced asymmetrical dimethylation (aDMA) of hnRNPK strongly impacted the protein's ability to promote the activity of the HIV-1 IRES. We also show that hnRNPK acts as an ITAF for the human T cell lymphotropic virus-type 1 (HTLV-1) IRES, present in the 5'UTR of the viral sense mRNA, but not for the IRES present in the antisense spliced transcript encoding the HTLV-1 basic leucine zipper protein (sHBZ). This study provides evidence for a novel role of the host hnRNPK as an ITAF that stimulates IRES-mediated translation initiation for the retroviruses HIV-1 and HTLV-1.
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Affiliation(s)
- Yazmín Fuentes
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Valeria Olguín
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Brenda López-Ulloa
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Dafne Mendonça
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Hade Ramos
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Ana Luiza Abdalla
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Gabriel Guajardo-Contreras
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Meijuan Niu
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada
| | - Barbara Rojas-Araya
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Quebec H3T 1E2, Canada
- Department of Microbiology and Immunology, McGill University, Montreal, Quebec H4A 3J1, Canada
- Department of Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | - Marcelo López-Lastra
- Laboratorio de Virología Molecular, Instituto Milenio de Inmunología e Inmunoterapia, Departamento de Enfermedades Infecciosas e Inmunología Pediátrica, Escuela de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 391, Santiago, Chile
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2
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Rahn K, Abdallah AT, Gan L, Herbrich S, Sonntag R, Benitez O, Malaney P, Zhang X, Rodriguez AG, Brottem J, Marx G, Brümmendorf TH, Ostareck DH, Ostareck-Lederer A, Crysandt M, Post SM, Naarmann-de Vries IS. Insight into the mechanism of AML del(9q) progression: hnRNP K targets the myeloid master regulators CEBPA (C/EBPα) and SPI1 (PU.1). BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2024; 1867:195004. [PMID: 38008244 DOI: 10.1016/j.bbagrm.2023.195004] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 11/08/2023] [Accepted: 11/20/2023] [Indexed: 11/28/2023]
Abstract
Deletions on the long arm of chromosome 9 (del(9q)) are recurrent abnormalities in about 2 % of acute myeloid leukemia cases, which usually involve HNRNPK and are frequently associated with other known aberrations. Based on an Hnrnpk haploinsufficient mouse model, a recent study demonstrated a function of hnRNP K in pathogenesis of myeloid malignancies via the regulation of cellular proliferation and myeloid differentiation programs. Here, we provide evidence that reduced hnRNP K expression results in the dysregulated expression of C/EBPα and additional transcription factors. CyTOF analysis revealed monocytic skewing with increased levels of mature myeloid cells. To explore the role of hnRNP K during normal and pathological myeloid differentiation in humans, we characterized hnRNP K-interacting RNAs in human AML cell lines. Notably, RNA-sequencing revealed several mRNAs encoding key transcription factors involved in the regulation of myeloid differentiation as targets of hnRNP K. We showed that specific sequence motifs confer the interaction of SPI1 and CEBPA 5' and 3'UTRs with hnRNP K. The siRNA mediated reduction of hnRNP K in human AML cells resulted in an increase of PU.1 and C/EBPα that is most pronounced for the p30 isoform. The combinatorial treatment with the inducer of myeloid differentiation valproic acid resulted in increased C/EBPα expression and myeloid differentiation. Together, our results indicate that hnRNP K post-transcriptionally regulates the expression of myeloid master transcription factors. These novel findings can inaugurate novel options for targeted treatment of AML del(9q) by modulation of hnRNP K function.
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Affiliation(s)
- Kerstin Rahn
- Department of Intensive Care Medicine, University Hospital RWTH Aachen University, Aachen, Germany; Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ali T Abdallah
- Interdisciplinary Center for Clinical Research (IZKF) Aachen, RWTH Aachen University, Germany; Cluster of Excellence on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Lin Gan
- Interdisciplinary Center for Clinical Research (IZKF) Aachen, RWTH Aachen University, Germany
| | - Shelley Herbrich
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Roland Sonntag
- Department of Internal Medicine III, University Hospital RWTH Aachen University, Aachen, Germany
| | - Oscar Benitez
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Prerna Malaney
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Xiaorui Zhang
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Ashely G Rodriguez
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jared Brottem
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Gernot Marx
- Department of Intensive Care Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Tim H Brümmendorf
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, University Hospital RWTH Aachen University, Aachen, Germany; Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), Aachen, Germany
| | - Dirk H Ostareck
- Department of Intensive Care Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Antje Ostareck-Lederer
- Department of Intensive Care Medicine, University Hospital RWTH Aachen University, Aachen, Germany
| | - Martina Crysandt
- Department of Hematology, Oncology, Hemostaseology and Stem Cell Transplantation, University Hospital RWTH Aachen University, Aachen, Germany; Center for Integrated Oncology Aachen Bonn Cologne Duesseldorf (CIO ABCD), Aachen, Germany
| | - Sean M Post
- Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.
| | - Isabel S Naarmann-de Vries
- Department of Intensive Care Medicine, University Hospital RWTH Aachen University, Aachen, Germany; Section of Bioinformatics and Systems Cardiology, University Hospital Heidelberg, Heidelberg, Germany.
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3
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Ratovitski T, Kamath SV, O'Meally RN, Gosala K, Holland CD, Jiang M, Cole RN, Ross CA. Arginine methylation of RNA-binding proteins is impaired in Huntington's disease. Hum Mol Genet 2023; 32:3006-3025. [PMID: 37535888 PMCID: PMC10549789 DOI: 10.1093/hmg/ddad125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Revised: 07/29/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Huntington's disease (HD) is a progressive neurodegenerative disorder caused by a CAG repeat expansion in the HD gene, coding for huntingtin protein (HTT). Mechanisms of HD cellular pathogenesis remain undefined and likely involve disruptions in many cellular processes and functions presumably mediated by abnormal protein interactions of mutant HTT. We previously found HTT interaction with several protein arginine methyl-transferase (PRMT) enzymes. Protein arginine methylation mediated by PRMT enzymes is an important post-translational modification with an emerging role in neurodegeneration. We found that normal (but not mutant) HTT can facilitate the activity of PRMTs in vitro and the formation of arginine methylation complexes. These interactions appear to be disrupted in HD neurons. This suggests an additional functional role for HTT/PRMT interactions, not limited to substrate/enzyme relationship, which may result in global changes in arginine protein methylation in HD. Our quantitative analysis of striatal precursor neuron proteome indicated that arginine protein methylation is significantly altered in HD. We identified a cluster highly enriched in RNA-binding proteins with reduced arginine methylation, which is essential to their function in RNA processing and splicing. We found that several of these proteins interact with HTT, and their RNA-binding and localization are affected in HD cells likely due to a compromised arginine methylation and/or abnormal interactions with mutant HTT. These studies reveal a potential new mechanism for disruption of RNA processing in HD, involving a direct interaction of HTT with methyl-transferase enzymes and modulation of their activity and highlighting methylation of arginine as potential new therapeutic target for HD.
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Affiliation(s)
- Tamara Ratovitski
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Siddhi V Kamath
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Robert N O'Meally
- Department of Biological Chemistry, Mass Spectrometry and Proteomics Facility, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Keerthana Gosala
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Chloe D Holland
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Mali Jiang
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Robert N Cole
- Department of Biological Chemistry, Mass Spectrometry and Proteomics Facility, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Christopher A Ross
- Department of Psychiatry and Behavioral Sciences, Division of Neurobiology, Johns Hopkins University, Baltimore, MD 21287, USA
- Departments of Neurology, Neuroscience and Pharmacology, Johns Hopkins University, Baltimore, MD 21287, USA
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Zhao H, Wei Z, Shen G, Chen Y, Hao X, Li S, Wang R. Poly(rC)-binding proteins as pleiotropic regulators in hematopoiesis and hematological malignancy. Front Oncol 2022; 12:1045797. [PMID: 36452487 PMCID: PMC9701828 DOI: 10.3389/fonc.2022.1045797] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Accepted: 10/26/2022] [Indexed: 11/16/2022] Open
Abstract
Poly(rC)-binding proteins (PCBPs), a defined subfamily of RNA binding proteins, are characterized by their high affinity and sequence-specific interaction with poly-cytosine (poly-C). The PCBP family comprises five members, including hnRNP K and PCBP1-4. These proteins share a relatively similar structure motif, with triple hnRNP K homology (KH) domains responsible for recognizing and combining C-rich regions of mRNA and single- and double-stranded DNA. Numerous studies have indicated that PCBPs play a prominent role in hematopoietic cell growth, differentiation, and tumorigenesis at multiple levels of regulation. Herein, we summarized the currently available literature regarding the structural and functional divergence of various PCBP family members. Furthermore, we focused on their roles in normal hematopoiesis, particularly in erythropoiesis. More importantly, we also discussed and highlighted their involvement in carcinogenesis, including leukemia and lymphoma, aiming to clarify the pleiotropic roles and molecular mechanisms in the hematopoietic compartment.
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Affiliation(s)
- Huijuan Zhao
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Ziqing Wei
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, China
| | - Guomin Shen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Yixiang Chen
- Henan International Joint Laboratory of Thrombosis and Hemostasis, Henan University of Science and Technology, Luoyang, China.,Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Xueqin Hao
- Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Sanqiang Li
- Basic Medical College, Henan University of Science and Technology, Luoyang, China
| | - Rong Wang
- Department of Clinical Laboratory, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou, China
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5
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Wu HL, Li SM, Huang YC, Xia QD, Zhou P, Li XM, Yu X, Wang SG, Ye ZQ, Hu J. Transcriptional regulation and ubiquitination-dependent regulation of HnRNPK oncogenic function in prostate tumorigenesis. Cancer Cell Int 2021; 21:641. [PMID: 34857003 PMCID: PMC8641147 DOI: 10.1186/s12935-021-02331-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 11/10/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Heterogeneous nuclear ribonucleoprotein K (HnRNPK) is a nucleic acid-binding protein that regulates diverse biological events. Pathologically, HnRNPK proteins are frequently overexpressed and clinically correlated with poor prognosis in various types of human cancers and are therefore pursued as attractive therapeutic targets for select patients. However, both the transcriptional regulation and degradation of HnRNPK in prostate cancer remain poorly understood. METHODS qRT-PCR was used to detect the expression of HnRNPK mRNA and miRNA; Immunoblots and immunohistochemical assays were used to determine the levels of HnRNPK and other proteins. Flow cytometry was used to investigate cell cycle stage. MTS and clonogenic assays were used to investigate cell proliferation. Immunoprecipitation was used to analyse the interaction between SPOP and HnRNPK. A prostate carcinoma xenograft mouse model was used to detect the in vivo effects of HnRNPK and miRNA. RESULTS In the present study, we noted that HnRNPK emerged as an important player in the carcinogenesis process of prostate cancer. miR-206 and miR-613 suppressed HnRNPK expression by targeting its 3'-UTR in PrCa cell lines in which HnRNPK is overexpressed. To explore the potential biological function, proliferation and colony formation of PrCa cells in vitro and tumor growth in vivo were also dramatically suppressed upon reintroduction of miR-206/miR-613. We have further provided evidence that Cullin 3 SPOP is a novel upstream E3 ubiquitin ligase complex that governs HnRNPK protein stability and oncogenic functions by promoting the degradation of HnRNPK in polyubiquitination-dependent proteolysis in the prostate cancer setting. Moreover, prostate cancer-associated SPOP mutants fail to interact with and promote the destruction of HnRNPK proteins. CONCLUSION Our findings reveal new posttranscriptional and posttranslational modification mechanisms of HnRNPK regulation via miR-206/miR-613 and SPOP, respectively. More importantly, given the critical oncogenic role of HnRNPK and the high frequency of SPOP mutations in prostate cancer, our results provide a molecular rationale for the clinical investigation of novel strategies to combat prostate cancer based on SPOP genetic status.
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Affiliation(s)
- Huan-Lei Wu
- Department of Geriatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Sen-Mao Li
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China.,Department of Urology, Peking University First Hospital, Peking University, BeijingBeijing, 100034, China
| | - Yao-Chen Huang
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Qi-Dong Xia
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Peng Zhou
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Xian-Miao Li
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Xiao Yu
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Shao-Gang Wang
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Zhang-Qun Ye
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China
| | - Jia Hu
- Department of Urology, Institute of Urology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Liberalization Ave, No. 1095, Wuhan, 430030, P.R. China.
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6
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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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Arginine Methylation of hnRNPK Inhibits the DDX3-hnRNPK Interaction to Play an Anti-Apoptosis Role in Osteosarcoma Cells. Int J Mol Sci 2021; 22:ijms22189764. [PMID: 34575922 PMCID: PMC8469703 DOI: 10.3390/ijms22189764] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/03/2021] [Accepted: 09/06/2021] [Indexed: 11/16/2022] Open
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is an RNA/DNA binding protein involved in diverse cell processes; it is also a p53 coregulator that initiates apoptosis under DNA damage conditions. However, the upregulation of hnRNPK is correlated with cancer transformation, progression, and migration, whereas the regulatory role of hnRNPK in cancer malignancy remains unclear. We previously showed that arginine methylation of hnRNPK attenuated the apoptosis of U2OS osteosarcoma cells under DNA damage conditions, whereas the replacement of endogenous hnRNPK with a methylation-defective mutant inversely enhanced apoptosis. The present study further revealed that an RNA helicase, DDX3, whose C-terminus preferentially binds to the unmethylated hnRNPK and could promote such apoptotic enhancement. Moreover, C-terminus-truncated DDX3 induced significantly less apoptosis than full-length DDX3. Notably, we also identified a small molecule that docks at the ATP-binding site of DDX3, promotes the DDX3-hnRNPK interaction, and induces further apoptosis. Overall, we have shown that the arginine methylation of hnRNPK suppresses the apoptosis of U2OS cells via interfering with DDX3-hnRNPK interaction. On the other hand, DDX3-hnRNPK interaction with a proapoptotic role may serve as a target for promoting apoptosis in osteosarcoma cells.
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8
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Feng J, Li H, Li J, Meng P, Wang L, Liu C, Zhao S, Sun W, Zhang Y. hnRNPK knockdown alleviates NLRP3 inflammasome priming by repressing FLIP expression in Raw264.7 macrophages. Redox Rep 2021; 25:104-111. [PMID: 33269646 PMCID: PMC7717877 DOI: 10.1080/13510002.2020.1857157] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Objectives: Inflammation is an important predisposing and progressive factor in chronic kidney disease (CKD). Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is associated with many fundamental cellular processes, but in chronic inflammatory pathologies remains unclear. Methods: An in vitro peripheral inflammation model was established using lipopolysaccharide (LPS)-stimulated mouse RAW264.7 macrophages, followed by inflammasome activation by ATP treatment. Knockdown of hnRNPK by sihnRNPK and FLICE-like inhibitory protein (FLIP) by siFLIP transfection were achieved in Raw264.7 macrophages. ELISA was used to determine the expression of IL-1β, IL-18 and TNF-α. Real time PCR was applied to detect the mRNA levels of hnRNPK, NOD-like receptors family pyrin domain-containing 3 (NLRP3), FLIP, Caspase-1, IL-1β and IL-18. Western blot and immunofluorescence were performed to detect relevant protein expressions. Co-immunoprecipitation (Co-IP) was used to assess the interaction of hnRNPK with FLIP. Results: Results showed that LPS plus ATP activated NLRP3 inflammasome, which evidenced by the up-regulation of TNF-α, IL-1β and IL-18. Notably, hnRNPK and FLIP were significantly up-regulated in activated NLRP3 inflammasome of macrophages. HnRNPK or FLIP knockdown significantly suppressed the activation of NLRP3 inflammasome, as reflected by down-regulation of Caspase-1, IL-1β and IL-18. Importantly, hnRNPK could directly bind to FLIP in activated NLRP3 inflammasome. Discussion: Our findings suggest that hnRNPK could promote the activation of NLRP3 inflammasome by directly binding FLIP, which might provide potential new therapeutic targets for CKD.
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Affiliation(s)
- Junxia Feng
- The Central Laboratory, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Hongyan Li
- Department of nephrology, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Jingchun Li
- The Central Laboratory, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Ping Meng
- The Central Laboratory, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Lina Wang
- Department of nephrology, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Chunli Liu
- The Central Laboratory, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Shili Zhao
- Department of nephrology, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Wei Sun
- The Central Laboratory, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
| | - Yunfang Zhang
- Department of nephrology, Affiliated Huadu Hospital, Southern Medical University, Guangzhou, People's Republic of China
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9
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Hwang JW, Cho Y, Bae GU, Kim SN, Kim YK. Protein arginine methyltransferases: promising targets for cancer therapy. Exp Mol Med 2021; 53:788-808. [PMID: 34006904 PMCID: PMC8178397 DOI: 10.1038/s12276-021-00613-y] [Citation(s) in RCA: 102] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 02/08/2023] Open
Abstract
Protein methylation, a post-translational modification (PTM), is observed in a wide variety of cell types from prokaryotes to eukaryotes. With recent and rapid advancements in epigenetic research, the importance of protein methylation has been highlighted. The methylation of histone proteins that contributes to the epigenetic histone code is not only dynamic but is also finely controlled by histone methyltransferases and demethylases, which are essential for the transcriptional regulation of genes. In addition, many nonhistone proteins are methylated, and these modifications govern a variety of cellular functions, including RNA processing, translation, signal transduction, DNA damage response, and the cell cycle. Recently, the importance of protein arginine methylation, especially in cell cycle regulation and DNA repair processes, has been noted. Since the dysregulation of protein arginine methylation is closely associated with cancer development, protein arginine methyltransferases (PRMTs) have garnered significant interest as novel targets for anticancer drug development. Indeed, several PRMT inhibitors are in phase 1/2 clinical trials. In this review, we discuss the biological functions of PRMTs in cancer and the current development status of PRMT inhibitors in cancer therapy.
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Affiliation(s)
- Jee Won Hwang
- grid.412670.60000 0001 0729 3748Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, Seoul, 04310 Republic of Korea
| | - Yena Cho
- grid.412670.60000 0001 0729 3748Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, Seoul, 04310 Republic of Korea
| | - Gyu-Un Bae
- grid.412670.60000 0001 0729 3748Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, Seoul, 04310 Republic of Korea
| | - Su-Nam Kim
- grid.35541.360000000121053345Natural Product Research Institute, Korea Institute of Science and Technology, Gangneung, 25451 Republic of Korea
| | - Yong Kee Kim
- grid.412670.60000 0001 0729 3748Research Institute of Pharmaceutical Sciences, College of Pharmacy, Sookmyung Women’s University, Seoul, 04310 Republic of Korea
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Naarmann-de Vries IS, Senatore R, Moritz B, Marx G, Urlaub H, Niessing D, Ostareck DH, Ostareck-Lederer A. Methylated HNRNPK acts on RPS19 to regulate ALOX15 synthesis in erythropoiesis. Nucleic Acids Res 2021; 49:3507-3523. [PMID: 33660773 PMCID: PMC8034617 DOI: 10.1093/nar/gkab116] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 02/11/2021] [Indexed: 11/23/2022] Open
Abstract
Post-transcriptional control is essential to safeguard structural and metabolic changes in enucleated reticulocytes during their terminal maturation to functional erythrocytes. The timely synthesis of arachidonate 15-lipoxygenase (ALOX15), which initiates mitochondria degradation at the final stage of reticulocyte maturation is regulated by the multifunctional protein HNRNPK. It constitutes a silencing complex at the ALOX15 mRNA 3′ untranslated region that inhibits translation initiation at the AUG by impeding the joining of ribosomal 60S subunits to 40S subunits. To elucidate how HNRNPK interferes with 80S ribosome assembly, three independent screens were applied. They consistently demonstrated a differential interaction of HNRNPK with RPS19, which is localized at the head of the 40S subunit and extends into its functional center. During induced erythroid maturation of K562 cells, decreasing arginine dimethylation of HNRNPK is linked to a reduced interaction with RPS19 in vitro and in vivo. Dimethylation of residues R256, R258 and R268 in HNRNPK affects its interaction with RPS19. In noninduced K562 cells, RPS19 depletion results in the induction of ALOX15 synthesis and mitochondria degradation. Interestingly, residue W52 in RPS19, which is frequently mutated in Diamond-Blackfan Anemia (DBA), participates in specific HNRNPK binding and is an integral part of a putative aromatic cage.
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Affiliation(s)
| | - Roberta Senatore
- Department of Intensive Care Medicine, University Hospital, RWTH Aachen University, Aachen Germany
| | - Bodo Moritz
- Institute of Pharmacy, Faculty of Natural Sciences, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Gernot Marx
- Department of Intensive Care Medicine, University Hospital, RWTH Aachen University, Aachen Germany
| | - Henning Urlaub
- Max-Planck-Institute for Biophysical Chemistry, Bioanalytical Mass Spectrometry Group, Göttingen, Germany.,Department of Clinical Chemistry, University Medical Center, Göttingen, Germany
| | - Dierk Niessing
- Institute of Pharmaceutical Biotechnology, Ulm University, Ulm, Germany.,Institute of Structural Biology, Helmholtz Zentrum München, Neuherberg, Germany
| | - Dirk H Ostareck
- Department of Intensive Care Medicine, University Hospital, RWTH Aachen University, Aachen Germany
| | - Antje Ostareck-Lederer
- Department of Intensive Care Medicine, University Hospital, RWTH Aachen University, Aachen Germany
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11
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Velázquez-Cruz A, Baños-Jaime B, Díaz-Quintana A, De la Rosa MA, Díaz-Moreno I. Post-translational Control of RNA-Binding Proteins and Disease-Related Dysregulation. Front Mol Biosci 2021; 8:658852. [PMID: 33987205 PMCID: PMC8111222 DOI: 10.3389/fmolb.2021.658852] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/22/2021] [Indexed: 12/20/2022] Open
Abstract
Cell signaling mechanisms modulate gene expression in response to internal and external stimuli. Cellular adaptation requires a precise and coordinated regulation of the transcription and translation processes. The post-transcriptional control of mRNA metabolism is mediated by the so-called RNA-binding proteins (RBPs), which assemble with specific transcripts forming messenger ribonucleoprotein particles of highly dynamic composition. RBPs constitute a class of trans-acting regulatory proteins with affinity for certain consensus elements present in mRNA molecules. However, these regulators are subjected to post-translational modifications (PTMs) that constantly adjust their activity to maintain cell homeostasis. PTMs can dramatically change the subcellular localization, the binding affinity for RNA and protein partners, and the turnover rate of RBPs. Moreover, the ability of many RBPs to undergo phase transition and/or their recruitment to previously formed membrane-less organelles, such as stress granules, is also regulated by specific PTMs. Interestingly, the dysregulation of PTMs in RBPs has been associated with the pathophysiology of many different diseases. Abnormal PTM patterns can lead to the distortion of the physiological role of RBPs due to mislocalization, loss or gain of function, and/or accelerated or disrupted degradation. This Mini Review offers a broad overview of the post-translational regulation of selected RBPs and the involvement of their dysregulation in neurodegenerative disorders, cancer and other pathologies.
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Affiliation(s)
- Alejandro Velázquez-Cruz
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Blanca Baños-Jaime
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Antonio Díaz-Quintana
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Miguel A De la Rosa
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
| | - Irene Díaz-Moreno
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de la Cartuja, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Seville, Spain
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12
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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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13
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RNA-binding motifs of hnRNP K are critical for induction of antibody diversification by activation-induced cytidine deaminase. Proc Natl Acad Sci U S A 2020; 117:11624-11635. [PMID: 32385154 DOI: 10.1073/pnas.1921115117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Activation-induced cytidine deaminase (AID) is the key enzyme for class switch recombination (CSR) and somatic hypermutation (SHM) to generate antibody memory. Previously, heterogeneous nuclear ribonucleoprotein K (hnRNP K) was shown to be required for AID-dependent DNA breaks. Here, we defined the function of major RNA-binding motifs of hnRNP K, GXXGs and RGGs in the K-homology (KH) and the K-protein-interaction (KI) domains, respectively. Mutation of GXXG, RGG, or both impaired CSR, SHM, and cMyc/IgH translocation equally, showing that these motifs were necessary for AID-dependent DNA breaks. AID-hnRNP K interaction is dependent on RNA; hence, mutation of these RNA-binding motifs abolished the interaction with AID, as expected. Some of the polypyrimidine sequence-carrying prototypical hnRNP K-binding RNAs, which participate in DNA breaks or repair bound to hnRNP K in a GXXG and RGG motif-dependent manner. Mutation of the GXXG and RGG motifs decreased nuclear retention of hnRNP K. Together with the previous finding that nuclear localization of AID is necessary for its function, lower nuclear retention of these mutants may worsen their functional deficiency, which is also caused by their decreased RNA-binding capacity. In summary, hnRNP K contributed to AID-dependent DNA breaks with all of its major RNA-binding motifs.
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14
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Xu Y, Wu W, Han Q, Wang Y, Li C, Zhang P, Xu H. Post-translational modification control of RNA-binding protein hnRNPK function. Open Biol 2020; 9:180239. [PMID: 30836866 PMCID: PMC6451366 DOI: 10.1098/rsob.180239] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNPK), a ubiquitously occurring RNA-binding protein (RBP), can interact with numerous nucleic acids and various proteins and is involved in a number of cellular functions including transcription, translation, splicing, chromatin remodelling, etc. Through its abundant biological functions, hnRNPK has been implicated in cellular events including proliferation, differentiation, apoptosis, DNA damage repair and the stress and immune responses. Thus, it is critical to understand the mechanism of hnRNPK regulation and its downstream effects on cancer and other diseases. A number of recent studies have highlighted that several post-translational modifications (PTMs) possibly play an important role in modulating hnRNPK function. Phosphorylation is the most widely occurring PTM in hnRNPK. For example, in vivo analyses of sites such as S116 and S284 illustrate the purpose of PTM of hnRNPK in altering its subcellular localization and its ability to bind target nucleic acids or proteins. Other PTMs such as methylation, ubiquitination, sumoylation, glycosylation and proteolytic cleavage are increasingly implicated in the regulation of DNA repair, cellular stresses and tumour growth. In this review, we describe the PTMs that impact upon hnRNPK function on gene expression programmes and different disease states. This knowledge is key in allowing us to better understand the mechanism of hnRNPK regulation.
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Affiliation(s)
- Yongjie Xu
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Wei Wu
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Qiu Han
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Yaling Wang
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Cencen Li
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Pengpeng Zhang
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
| | - Haixia Xu
- College of Life Science, Xinyang Normal University , Xinyang 464000 , People's Republic of China
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15
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Li M, Zhang W, Yang X, Liu H, Cao L, Li W, Wang L, Zhang G, Gao R. Downregulation of HNRNPK in human cancer cells inhibits lung metastasis. Animal Model Exp Med 2019; 2:291-296. [PMID: 31942561 PMCID: PMC6930993 DOI: 10.1002/ame2.12090] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/29/2019] [Accepted: 10/31/2019] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Lung cancer frequently occurs in the clinic, leading to poor prognosis and high mortality. Markers for early diagnosis of lung cancer are scarce, and further potential therapeutic targets are also urgently needed. METHOD We established a new mouse model in which the specific gene HNRNPK (heterogeneous nuclear ribonucleoprotein K) was downregulated after administration of doxycycline. The lung metastatic nodules were investigated using bioluminescence imaging, micro-CT, and autopsy quantification. RESULTS Compared with the short hairpin negative control group, less lung metastatic nodules were formed in the short hairpin RNA group. CONCLUSION Downregulation of HNRNPK in cancer cells can inhibit lung metastasis.
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Affiliation(s)
- Mengyuan Li
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Wenlong Zhang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Xingjiu Yang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Hongfei Liu
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Lin Cao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Weisha Li
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Le Wang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Guoxin Zhang
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
| | - Ran Gao
- Key Laboratory of Human Disease Comparative Medicine (National Health and Family Planning Commission)The Institute of Laboratory Animal ScienceChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijingP.R. China
- Beijing Engineering Research Center for Experimental Animal Models of Human Critical DiseasesBeijingP.R. China
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Katsanovskaja K, Driver T, Pipkorn R, Edelson-Averbukh M. Negative Ion Mode Collision-Induced Dissociation for Analysis of Protein Arginine Methylation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:1229-1241. [PMID: 30915654 PMCID: PMC6591203 DOI: 10.1007/s13361-019-02176-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 02/21/2019] [Accepted: 03/01/2019] [Indexed: 06/09/2023]
Abstract
Arginine methylation is a common protein post-translational modification (PTM) that plays a key role in eukaryotic cells. Three distinct types of this modification are found in mammals: asymmetric Nη1Nη1-dimethylarginine (aDMA), symmetric Nη1Nη2-dimethylarginine (sDMA), and an intermediate Nη1-monomethylarginine (MMA). Elucidation of regulatory mechanisms of arginine methylation in living organisms requires precise information on both the type of the modified residues and their location inside the protein amino acid sequences. Despite mass spectrometry (MS) being the method of choice for analysis of multiple protein PTMs, unambiguous characterization of protein arginine methylation may not be always straightforward. Indeed, frequent internal basic residues of Arg methylated tryptic peptides hamper their sequencing under positive ion mode collision-induced dissociation (CID), the standardly used tandem mass spectrometry method, while the relative stability of the aDMA and sDMA side chains under alternative non-ergodic electron-based fragmentation techniques, electron-capture and electron transfer dissociations (ECD and ETD), may impede differentiation between the isobaric residues. Here, for the first time, we demonstrate the potential of the negative ion mode collision-induced dissociation MS for analysis of protein arginine methylation and present data revealing that the negative polarity approach can deliver both an unambiguous identification of the arginine methylation type and extensive information on the modified peptide sequences.
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Affiliation(s)
| | - Taran Driver
- Department of Physics, Imperial College London, London, SW7 2AZ, UK
| | - Rüdiger Pipkorn
- Department of Translational Immunology, German Cancer Research Centre, INF 580, 69120, Heidelberg, Germany
| | - Marina Edelson-Averbukh
- Department of Chemistry, Imperial College London, London, SW7 2AZ, UK.
- Department of Physics, Imperial College London, London, SW7 2AZ, UK.
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17
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hnRNPK S379 phosphorylation participates in migration regulation of triple negative MDA-MB-231 cells. Sci Rep 2019; 9:7611. [PMID: 31110205 PMCID: PMC6527834 DOI: 10.1038/s41598-019-44063-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 03/18/2019] [Indexed: 12/14/2022] Open
Abstract
We have previously identified a novel Aurora-A-mediated Serine 379 (S379) phosphorylation of a poly(C)-binding protein, hnRNPK, the overexpression of which is frequently observed in various cancers. It is known that the oncogenic Aurora-A kinase promotes the malignancy of cancer cells. This study aims to investigate the unexplored functions of hnRNPK S379 phosphorylation using MDA-MB-231 cells, a triple negative breast cancer cell that has amplification of the Aurora-A kinase gene. Accordingly, we established two cell lines in which the endogenous hnRNPK was replaced with either S379D or S379A hnRNPK respectively. Notably, we found that a phosphorylation-mimic S379D mutant of hnRNPK suppressed cell migration and, conversely, a phosphorylation-defective S379A mutant promoted migration. Moreover, Twist was downregulated upon hnRNPK S379 phosphorylation, whereas β-catenin and MMP12 were increased when there was loss of hnRNPK S379 phosphorylation in MDA-MB-231 cells. Furthermore, S379A hnRNPK increases stability of β-catenin in MDA-MB-231 cells. In conclusion, our results suggest that hnRNPK S379 phosphorylation regulates migration via the EMT signaling pathway.
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18
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Ostareck DH, Ostareck-Lederer A. RNA-Binding Proteins in the Control of LPS-Induced Macrophage Response. Front Genet 2019; 10:31. [PMID: 30778370 PMCID: PMC6369361 DOI: 10.3389/fgene.2019.00031] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Accepted: 01/17/2019] [Indexed: 12/18/2022] Open
Abstract
Innate immune response is triggered by pathogen components, like lipopolysaccharides (LPS) of gram-negative bacteria. LPS initiates Toll-like receptor 4 (TLR4) signaling, which involves mitogen activated protein kinases (MAPK) and nuclear factor kappa B (NFκB) in different pathway branches and ultimately induces inflammatory cytokine and chemokine expression, macrophage migration and phagocytosis. Timely gene transcription and post-transcriptional control of gene expression confer the adequate synthesis of signaling molecules. As trans-acting factors RNA binding proteins (RBPs) contribute significantly to the surveillance of gene expression. RBPs are involved in the regulation of mRNA processing, localization, stability and translation. Thereby they enable rapid cellular responses to inflammatory mediators and facilitate a coordinated systemic immune response. Specific RBP binding to conserved sequence motifs in their target mRNAs is mediated by RNA binding domains, like Zink-finger domains, RNA recognition motifs (RRM), and hnRNP K homology domains (KH), often arranged in modular arrays. In this review, we focus on RBPs Tristetraprolin (TTP), human antigen R (HUR), T-cell intracellular antigen 1 related protein (TIAR), and heterogeneous ribonuclear protein K (hnRNP K) in LPS induced macrophages as primary responding immune cells. We discuss recent experiments employing RNA immunoprecipitation and microarray analysis (RIP-Chip) and newly developed individual-nucleotide resolution crosslinking and immunoprecipitation (iCLIP), photoactivatable ribonucleoside-enhanced crosslinking (PAR-iCLIP) and RNA sequencing techniques (RNA-Seq). The global mRNA interaction profile analysis of TTP, HUR, TIAR, and hnRNP K exhibited valuable information about the post-transcriptional control of inflammation related gene expression with a broad impact on intracellular signaling and temporal cytokine expression.
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Affiliation(s)
- Dirk H Ostareck
- Department of Intensive Care Medicine, University Hospital RWTH Aachen, Aachen, Germany
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19
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Chia SZ, Lai YW, Yagoub D, Lev S, Hamey JJ, Pang CNI, Desmarini D, Chen Z, Djordjevic JT, Erce MA, Hart-Smith G, Wilkins MR. Knockout of the Hmt1p Arginine Methyltransferase in Saccharomyces cerevisiae Leads to the Dysregulation of Phosphate-associated Genes and Processes. Mol Cell Proteomics 2018; 17:2462-2479. [PMID: 30206180 PMCID: PMC6283299 DOI: 10.1074/mcp.ra117.000214] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 08/14/2018] [Indexed: 11/06/2022] Open
Abstract
Hmt1p is the predominant arginine methyltransferase in Saccharomyces cerevisiae Its substrate proteins are involved in transcription, transcriptional regulation, nucleocytoplasmic transport and RNA splicing. Hmt1p-catalyzed methylation can also modulate protein-protein interactions. Hmt1p is conserved from unicellular eukaryotes through to mammals where its ortholog, PRMT1, is lethal upon knockout. In yeast, however, the effect of knockout on the transcriptome and proteome has not been described. Transcriptome analysis revealed downregulation of phosphate-responsive genes in hmt1Δ, including acid phosphatases PHO5, PHO11, and PHO12, phosphate transporters PHO84 and PHO89 and the vacuolar transporter chaperone VTC3 Analysis of the hmt1Δ proteome revealed decreased abundance of phosphate-associated proteins including phosphate transporter Pho84p, vacuolar alkaline phosphatase Pho8p, acid phosphatase Pho3p and subunits of the vacuolar transporter chaperone complex Vtc1p, Vtc3p and Vtc4p. Consistent with this, phosphate homeostasis was dysregulated in hmt1Δ cells, showing decreased extracellular phosphatase levels and decreased total Pi in phosphate-depleted medium. In vitro, we showed that transcription factor Pho4p can be methylated at Arg-241, which could explain phosphate dysregulation in hmt1Δ if interplay exists with phosphorylation at Ser-242 or Ser-243, or if Arg-241 methylation affects the capacity of Pho4p to homodimerize or interact with Pho2p. However, the Arg-241 methylation site was not validated in vivo and the localization of a Pho4p-GFP fusion in hmt1Δ was not different from wild type. To our knowledge, this is the first study to reveal an association between Hmt1p and phosphate homeostasis and one which suggests a regulatory link between S-adenosyl methionine and intracellular phosphate.
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Affiliation(s)
- Samantha Z Chia
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Yu-Wen Lai
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Daniel Yagoub
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Sophie Lev
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Joshua J Hamey
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Chi Nam Ignatius Pang
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Desmarini Desmarini
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Zhiliang Chen
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Julianne T Djordjevic
- Centre for Infectious Diseases and Microbiology, Westmead Millennium Institute and Sydney Medical School, University of Sydney at Westmead Hospital, Westmead, New South Wales, Australia
| | - Melissa A Erce
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Gene Hart-Smith
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Marc R Wilkins
- Systems Biology Initiative, School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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Characterization of acute myeloid leukemia with del(9q) - Impact of the genes in the minimally deleted region. Leuk Res 2018; 76:15-23. [PMID: 30476680 DOI: 10.1016/j.leukres.2018.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 11/13/2018] [Accepted: 11/15/2018] [Indexed: 02/06/2023]
Abstract
Acute myeloid leukemia is an aggressive disease that arises from clonal expansion of malignant hematopoietic precursor cells of the bone marrow. Deletions on the long arm of chromosome 9 (del(9q)) are observed in 2% of acute myeloid leukemia patients. Our deletion analysis in a cohort of 31 del(9q) acute myeloid leukemia patients further supports the importance of a minimally deleted region composed of seven genes potentially involved in leukemogenesis: GKAP1, KIF27, C9ORF64, HNRNPK, RMI1, SLC28A3 and NTRK2. Importantly, among them HNRNPK, encoding heterogeneous nuclear ribonucleoprotein K is proposed to function in leukemogenesis. We show that expression of HNRNPK and the other genes of the minimally deleted region is significantly reduced in patients with del(9q) compared with normal karyotype acute myeloid leukemia. Also, two mRNAs interacting with heterogeneous nuclear ribonucleoprotein K, namely CDKN1A and CEBPA are significantly downregulated. While the deletion size is not correlated with outcome, associated genetic aberrations are important. Patients with an additional t(8;21) show a good prognosis. RUNX1-RUNX1T1, which emerges from the t(8;21) leads to transcriptional down-regulation of CEBPA. Acute myeloid leukemia patients with mutations in CEBPA have a good prognosis as well. Interestingly, in del(9q) patients with CEBPA mutation mRNA levels of HNRNPK and the other genes located in the minimally deleted region is restored to normal karyotype level. Our data indicate that a link between CEBPA and the genes of the minimally deleted region, among them HNRNPK contributes to leukemogenesis in acute myeloid leukemia with del(9q).
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Xu Y, Li R, Zhang K, Wu W, Wang S, Zhang P, Xu H. The multifunctional RNA-binding protein hnRNPK is critical for the proliferation and differentiation of myoblasts. BMB Rep 2018; 51:350-355. [PMID: 29898807 PMCID: PMC6089871 DOI: 10.5483/bmbrep.2018.51.7.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Indexed: 11/20/2022] Open
Abstract
HnRNPK is a multifunctional protein that participates in chromatin remodeling, transcription, RNA splicing, mRNA stability and translation. Here, we uncovered the function of hnRNPK in regulating the proliferation and differentiation of myoblasts. hnRNPK was mutated in the C2C12 myoblast cell line using the CRISPR/Cas9 system. A decreased proliferation rate was observed in hnRNPK-mutated cells, suggesting an impaired proliferation phenotype. Furthermore, increased G2/M phase, decreased S phase and increased sub-G1 phase cells were detected in the hnRNPK-mutated cell lines. The expression analysis of key cell cycle regulators indicated mRNA of Cyclin A2 was significantly increased in the mutant myoblasts compared to the control cells, while Cyclin B1, Cdc25b and Cdc25c were decreased sharply. In addition to the myoblast proliferation defect, the mutant cells exhibited defect in myotube formation. The myotube formation marker, myosin heavy chain (MHC), was decreased sharply in hnRNPK-mutated cells compared to control myoblasts during differentiation. The deficiency in hnRNPK also resulted in the repression of Myog expression, a key myogenic regulator during differentiation. Together, our data demonstrate that hnRNPK is required for myoblast proliferation and differentiation and may be an essential regulator of myoblast function.
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Affiliation(s)
- Yongjie Xu
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Rui Li
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Kaili Zhang
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Wei Wu
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Suying Wang
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Pengpeng Zhang
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
| | - Haixia Xu
- College of Life Science, Xinyang Normal University, Xinyang 464000, China
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Chong PA, Vernon RM, Forman-Kay JD. RGG/RG Motif Regions in RNA Binding and Phase Separation. J Mol Biol 2018; 430:4650-4665. [PMID: 29913160 DOI: 10.1016/j.jmb.2018.06.014] [Citation(s) in RCA: 239] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 06/02/2018] [Accepted: 06/06/2018] [Indexed: 12/29/2022]
Abstract
RGG/RG motifs are RNA binding segments found in many proteins that can partition into membraneless organelles. They occur in the context of low-complexity disordered regions and often in multiple copies. Although short RGG/RG-containing regions can sometimes form high-affinity interactions with RNA structures, multiple RGG/RG repeats are generally required for high-affinity binding, suggestive of the dynamic, multivalent interactions that are thought to underlie phase separation in formation of cellular membraneless organelles. Arginine can interact with nucleotide bases via hydrogen bonding and π-stacking; thus, nucleotide conformers that provide access to the bases provide enhanced opportunities for RGG interactions. Methylation of RGG/RG regions, which is accomplished by protein arginine methyltransferase enzymes, occurs to different degrees in different cell types and may regulate the behavior of proteins containing these regions.
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Affiliation(s)
- P Andrew Chong
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Robert M Vernon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Julie D Forman-Kay
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON, Canada; Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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23
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Sohtome Y, Shimazu T, Barjau J, Fujishiro S, Akakabe M, Terayama N, Dodo K, Ito A, Yoshida M, Shinkai Y, Sodeoka M. Unveiling epidithiodiketopiperazine as a non-histone arginine methyltransferase inhibitor by chemical protein methylome analyses. Chem Commun (Camb) 2018; 54:9202-9205. [DOI: 10.1039/c8cc03907k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We present a chemical methylome analysis to evaluate the inhibitory activity of small molecules towards poorly characterized protein methyltransferases.
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24
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Murn J, Shi Y. The winding path of protein methylation research: milestones and new frontiers. Nat Rev Mol Cell Biol 2017; 18:517-527. [PMID: 28512349 DOI: 10.1038/nrm.2017.35] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In 1959, while analysing the bacterial flagellar proteins, Ambler and Rees observed an unknown species of amino acid that they eventually identified as methylated lysine. Over half a century later, protein methylation is known to have a regulatory role in many essential cellular processes that range from gene transcription to signal transduction. However, the road to this now burgeoning research field was obstacle-ridden, not least because of the inconspicuous nature of the methyl mark itself. Here, we chronicle the milestone achievements and discuss the future of protein methylation research.
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Affiliation(s)
- Jernej Murn
- Department of Cell Biology, Harvard Medical School, and the Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts 02115, USA
| | - Yang Shi
- Department of Cell Biology, Harvard Medical School, and the Division of Newborn Medicine, Boston Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts 02115, USA
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Butler JS, Qiu YH, Zhang N, Yoo SY, Coombes KR, Dent SYR, Kornblau SM. Low expression of ASH2L protein correlates with a favorable outcome in acute myeloid leukemia. Leuk Lymphoma 2016; 58:1207-1218. [PMID: 28185526 DOI: 10.1080/10428194.2016.1235272] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
ASH2L encodes a trithorax group protein that is a core component of all characterized mammalian histone H3K4 methyltransferase complexes, including mixed lineage leukemia (MLL) complexes. ASH2L protein levels in primary leukemia patient samples have not yet been defined. We analyzed ASH2L protein expression in 511 primary AML patient samples using reverse phase protein array (RPPA) technology. We discovered that ASH2L expression is significantly increased in a subset of patients carrying fms-related tyrosine kinase 3 (FLT3) mutations. Furthermore, we observed that low levels of ASH2L are associated with increased overall survival. We also compared ASH2L levels to the expression of 230 proteins previously analyzed on this array. ASH2L expression was inversely correlated with 32 proteins, mostly involved in cell adhesion and cell cycle inhibition, while a positive correlation was observed for 50 proteins, many of which promote cell proliferation. Together, these results indicate that a lower level of ASH2L protein is beneficial to AML patients.
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Affiliation(s)
- Jill S Butler
- a Department of Epigenetics and Molecular Carcinogenesis , The University of Texas MD Anderson Cancer Center , Science Park , Smithville , TX , USA.,b Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center , Houston , TX , USA
| | - Yi Hua Qiu
- c Division of Molecular Hematology, Department of Leukemia , The University of Texas MD Anderson Cancer Center , Houston , TX , USA
| | | | - Suk-Young Yoo
- e Department of Bioinformatics and Computational Biology , The University of Texas MD Anderson Cancer Center , Houston , TX , USA
| | - Kevin R Coombes
- f Department of Biomedical Informatics , The Ohio State University College of Medicine , Columbus , OH , USA
| | - Sharon Y R Dent
- a Department of Epigenetics and Molecular Carcinogenesis , The University of Texas MD Anderson Cancer Center , Science Park , Smithville , TX , USA.,b Center for Cancer Epigenetics, The University of Texas MD Anderson Cancer Center , Houston , TX , USA
| | - Steven M Kornblau
- c Division of Molecular Hematology, Department of Leukemia , The University of Texas MD Anderson Cancer Center , Houston , TX , USA
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26
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Liepelt A, Naarmann-de Vries IS, Simons N, Eichelbaum K, Föhr S, Archer SK, Castello A, Usadel B, Krijgsveld J, Preiss T, Marx G, Hentze MW, Ostareck DH, Ostareck-Lederer A. Identification of RNA-binding Proteins in Macrophages by Interactome Capture. Mol Cell Proteomics 2016; 15:2699-714. [PMID: 27281784 DOI: 10.1074/mcp.m115.056564] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Indexed: 12/11/2022] Open
Abstract
Pathogen components, such as lipopolysaccharides of Gram-negative bacteria that activate Toll-like receptor 4, induce mitogen activated protein kinases and NFκB through different downstream pathways to stimulate pro- and anti-inflammatory cytokine expression. Importantly, post-transcriptional control of the expression of Toll-like receptor 4 downstream signaling molecules contributes to the tight regulation of inflammatory cytokine synthesis in macrophages. Emerging evidence highlights the role of RNA-binding proteins (RBPs) in the post-transcriptional control of the innate immune response. To systematically identify macrophage RBPs and their response to LPS stimulation, we employed RNA interactome capture in LPS-induced and untreated murine RAW 264.7 macrophages. This combines RBP-crosslinking to RNA, cell lysis, oligo(dT) capture of polyadenylated RNAs and mass spectrometry analysis of associated proteins. Our data revealed 402 proteins of the macrophage RNA interactome including 91 previously not annotated as RBPs. A comparison with published RNA interactomes classified 32 RBPs uniquely identified in RAW 264.7 macrophages. Of these, 19 proteins are linked to biochemical activities not directly related to RNA. From this group, we validated the HSP90 cochaperone P23 that was demonstrated to exhibit cytosolic prostaglandin E2 synthase 3 (PTGES3) activity, and the hematopoietic cell-specific LYN substrate 1 (HCLS1 or HS1), a hematopoietic cell-specific adapter molecule, as novel macrophage RBPs. Our study expands the mammalian RBP repertoire, and identifies macrophage RBPs that respond to LPS. These RBPs are prime candidates for the post-transcriptional regulation and execution of LPS-induced signaling pathways and the innate immune response. Macrophage RBP data have been deposited to ProteomeXchange with identifier PXD002890.
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Affiliation(s)
- Anke Liepelt
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Isabel S Naarmann-de Vries
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Nadine Simons
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Katrin Eichelbaum
- §European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Sophia Föhr
- §European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Stuart K Archer
- ¶EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Garran Rd, Acton (Canberra) ACT 2601, Australia
| | - Alfredo Castello
- §European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Björn Usadel
- ‖Institute of Biology I, RWTH Aachen, Worringer Weg 2, 52074 Aachen, Germany
| | - Jeroen Krijgsveld
- §European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Thomas Preiss
- ¶EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Garran Rd, Acton (Canberra) ACT 2601, Australia; **Victor Chang Cardiac Research Institute, Darlinghurst (Sydney), New South Wales 2010, Australia
| | - Gernot Marx
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany
| | - Matthias W Hentze
- §European Molecular Biology Laboratory (EMBL), Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Dirk H Ostareck
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany;
| | - Antje Ostareck-Lederer
- From the ‡Department of Intensive Care and Intermediate Care, University Hospital RWTH Aachen, Pauwelsstr. 30, 52074 Aachen, Germany;
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Monomethylated and unmethylated FUS exhibit increased binding to Transportin and distinguish FTLD-FUS from ALS-FUS. Acta Neuropathol 2016; 131:587-604. [PMID: 26895297 DOI: 10.1007/s00401-016-1544-2] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 12/11/2022]
Abstract
Deposition of the nuclear DNA/RNA-binding protein Fused in sarcoma (FUS) in cytosolic inclusions is a common hallmark of some cases of frontotemporal lobar degeneration (FTLD-FUS) and amyotrophic lateral sclerosis (ALS-FUS). Whether both diseases also share common pathological mechanisms is currently unclear. Based on our previous finding that FUS deposits are hypomethylated in FTLD-FUS but not in ALS-FUS, we have now investigated whether genetic or pharmacological inactivation of Protein arginine methyltransferase 1 (PRMT1) activity results in unmethylated FUS or in alternatively methylated forms of FUS. To do so, we generated FUS-specific monoclonal antibodies that specifically recognize unmethylated arginine (UMA), monomethylated arginine (MMA) or asymmetrically dimethylated arginine (ADMA). Loss of PRMT1 indeed not only results in an increase of UMA FUS and a decrease of ADMA FUS, but also in a significant increase of MMA FUS. Compared to ADMA FUS, UMA and MMA FUS exhibit much higher binding affinities to Transportin-1, the nuclear import receptor of FUS, as measured by pull-down assays and isothermal titration calorimetry. Moreover, we show that MMA FUS occurs exclusively in FTLD-FUS, but not in ALS-FUS. Our findings therefore provide additional evidence that FTLD-FUS and ALS-FUS are caused by distinct disease mechanisms although both share FUS deposits as a common denominator.
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28
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Naarmann-de Vries IS, Brendle A, Bähr-Ivacevic T, Benes V, Ostareck DH, Ostareck-Lederer A. Translational control mediated by hnRNP K links NMHC IIA to erythroid enucleation. J Cell Sci 2016; 129:1141-54. [PMID: 26823606 DOI: 10.1242/jcs.174995] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 01/20/2016] [Indexed: 12/20/2022] Open
Abstract
Post-transcriptional regulation is crucial for structural and functional alterations in erythropoiesis. Enucleation of erythroid progenitors precedes reticulocyte release into circulation. In enucleated cells, reticulocyte 15-lipoxygenase (r15-LOX, also known as ALOX15) initiates mitochondria degradation. Regulation of r15-LOX mRNA translation by hnRNP K determines timely r15-LOX synthesis in terminal maturation. K562 cells induced for erythroid maturation recapitulate enucleation and mitochondria degradation. HnRNP K depletion from maturing K562 cells results in enhanced enucleation, which even occurs independently of maturation. We performed RIP-Chip analysis to identify hnRNP K-interacting RNAs comprehensively. Non-muscle myosin heavy chain (NMHC) IIA (also known as MYH9) mRNA co-purified with hnRNP K from non-induced K562 cells, but not from mature cells. NMHC IIA protein increase in erythroid maturation at constant NMHC IIA mRNA levels indicates post-transcriptional regulation. We demonstrate that binding of hnRNP K KH domain 3 to a specific sequence element in the NMHC IIA mRNA 3'UTR mediates translation regulation in vitro Importantly, elevated NMHC IIA expression results in erythroid-maturation-independent enucleation as shown for hnRNP K depletion. Our data provide evidence that hnRNP-K-mediated regulation of NMHC IIA mRNA translation contributes to the control of enucleation in erythropoiesis.
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Affiliation(s)
- Isabel S Naarmann-de Vries
- Department of Intensive Care and Intermediate Care, Experimental Research Unit, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, Aachen 52074, Germany
| | - Annika Brendle
- Department of Intensive Care and Intermediate Care, Experimental Research Unit, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, Aachen 52074, Germany
| | - Tomi Bähr-Ivacevic
- Genomics Core Facility, EMBL, Meyerhofstraße 1, Heidelberg 69117, Germany
| | - Vladimir Benes
- Genomics Core Facility, EMBL, Meyerhofstraße 1, Heidelberg 69117, Germany
| | - Dirk H Ostareck
- Department of Intensive Care and Intermediate Care, Experimental Research Unit, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, Aachen 52074, Germany
| | - Antje Ostareck-Lederer
- Department of Intensive Care and Intermediate Care, Experimental Research Unit, University Hospital, RWTH Aachen University, Pauwelsstrasse 30, Aachen 52074, Germany
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29
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Jiang X, Yao F, Li X, Jia B, Zhong G, Zhang J, Zou X, Hou L. Molecular cloning, characterization and expression analysis of the protein arginine N-methyltransferase 1 gene (As-PRMT1) from Artemia sinica. Gene 2015; 565:122-9. [PMID: 25843627 DOI: 10.1016/j.gene.2015.04.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/17/2015] [Accepted: 04/01/2015] [Indexed: 10/23/2022]
Abstract
Protein arginine N-methyltransferase 1 (PRMT1) is an important epigenetic regulation factor in eukaryotic genomes. PRMT1 is involved in histone arginine loci methylation modification, changes in eukaryotic genomes' chromatin structure, and gene expression regulation. In the present paper, the full-length 1201-bp cDNA sequence of the PRMT1 homolog of Artemia sinica (As-PRMT1) was cloned for the first time. The putative As-PRMT1 protein comprises 346 amino acids with a SAM domain and a PRMT5 domain. Multiple sequence alignments revealed that the putative sequence of As-PRMT1 protein was relatively conserved across species, especially in the SAM domain. As-PRMT1 is widely expressed during embryo development of A. sinica. This is followed by a dramatic upregulation after diapause termination and then downregulation from the nauplius stage. Furthermore, As-PRMT1 transcripts are highly upregulated under conditions of high salinity and low temperature stress. These findings suggested that As-PRMT1 is a stress-related factor that might promote or inhibit the expression of certain genes, play a critical role in embryonic development and in resistance to low temperature and high salinity stress.
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Affiliation(s)
- Xue Jiang
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Feng Yao
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Xuejie Li
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Baolin Jia
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Guangying Zhong
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Jianfeng Zhang
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China
| | - Xiangyang Zou
- Department of Biology, Dalian Medical University, Dalian 116044, China.
| | - Lin Hou
- College of Life Sciences, Liaoning Normal University, Dalian 116081, China.
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Barboro P, Ferrari N, Balbi C. Emerging roles of heterogeneous nuclear ribonucleoprotein K (hnRNP K) in cancer progression. Cancer Lett 2014; 352:152-9. [DOI: 10.1016/j.canlet.2014.06.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 12/18/2022]
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31
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Yang JH, Chiou YY, Fu SL, Shih IY, Weng TH, Lin WJ, Lin CH. Arginine methylation of hnRNPK negatively modulates apoptosis upon DNA damage through local regulation of phosphorylation. Nucleic Acids Res 2014; 42:9908-24. [PMID: 25104022 PMCID: PMC4150800 DOI: 10.1093/nar/gku705] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is an RNA/DNA-binding protein involved in chromatin remodeling, RNA processing and the DNA damage response. In addition, increased hnRNPK expression has been associated with tumor development and progression. A variety of post-translational modifications of hnRNPK have been identified and shown to regulate hnRNPK function, including phosphorylation, ubiquitination, sumoylation and methylation. However, the functional significance of hnRNPK arginine methylation remains unclear. In the present study, we demonstrated that the methylation of two essential arginines, Arg296 and Arg299, on hnRNPK inhibited a nearby Ser302 phosphorylation that was mediated through the pro-apoptotic kinase PKCδ. Notably, the engineered U2OS cells carrying an Arg296/Arg299 methylation-defective hnRNPK mutant exhibited increased apoptosis upon DNA damage. While such elevated apoptosis can be diminished through addition with wild-type hnRNPK, we further demonstrated that this increased apoptosis occurred through both intrinsic and extrinsic pathways and was p53 independent, at least in part. Here, we provide the first evidence that the arginine methylation of hnRNPK negatively regulates cell apoptosis through PKCδ-mediated signaling during DNA damage, which is essential for the anti-apoptotic role of hnRNPK in apoptosis and the evasion of apoptosis in cancer cells.
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Affiliation(s)
- Jen-Hao Yang
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming University, Taipei 11221, Taiwan
| | - Yi-Ying Chiou
- Institute of Biopharmaceutical Sciences, National Yang Ming University, Taipei 11221, Taiwan
| | - Shu-Ling Fu
- Institute of Traditional Medicine, National Yang-Ming University, Taipei 11221, Taiwan
| | - I-Yun Shih
- Institute of Biopharmaceutical Sciences, National Yang Ming University, Taipei 11221, Taiwan
| | - Tsai-Hsuan Weng
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming University, Taipei 11221, Taiwan
| | - Wey-Jinq Lin
- Institute of Biopharmaceutical Sciences, National Yang Ming University, Taipei 11221, Taiwan
| | - Chao-Hsiung Lin
- Department of Life Sciences and Institute of Genome Sciences, National Yang Ming University, Taipei 11221, Taiwan Institute of Biopharmaceutical Sciences, National Yang Ming University, Taipei 11221, Taiwan Proteomics Research Center, National Yang Ming University, Taipei 11221, Taiwan
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32
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Shelkovnikova TA, Robinson HK, Troakes C, Ninkina N, Buchman VL. Compromised paraspeckle formation as a pathogenic factor in FUSopathies. Hum Mol Genet 2013; 23:2298-312. [PMID: 24334610 PMCID: PMC3976330 DOI: 10.1093/hmg/ddt622] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Paraspeckles are nuclear bodies formed by a set of specialized proteins assembled on the long non-coding RNA NEAT1; they have a role in nuclear retention of hyperedited transcripts and are associated with response to cellular stress. Fused in sarcoma (FUS) protein, linked to a number of neurodegenerative disorders, is an essential paraspeckle component. We have shown that its recruitment to these nuclear structures is mediated by the N-terminal region and requires prion-like activity. FUS interacts with p54nrb/NONO, a major constituent of paraspeckles, in an RNA-dependent manner and responds in the same way as other paraspeckle proteins to alterations in cellular homeostasis such as changes in transcription rates or levels of protein methylation. FUS also regulates NEAT1 levels and paraspeckle formation in cultured cells, and FUS deficiency leads to loss of paraspeckles. Pathological gain-of-function FUS mutations might be expected to affect paraspeckle function in human diseases because mislocalized amyotrophic lateral sclerosis (ALS)-linked FUS variants sequester other paraspeckle proteins into aggregates formed in cultured cells and into neuronal inclusions in a transgenic mouse model of FUSopathy. Furthermore, we detected abundant p54nrb/NONO-positive inclusions in motor neurons of patients with familial forms of ALS caused by FUS mutations, but not in other ALS cases. Our results suggest that both loss and gain of FUS function can trigger disruption of paraspeckle assembly, which may impair protective responses in neurons and thereby contribute to the pathogenesis of FUSopathies.
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Friend LR, Landsberg MJ, Nouwens AS, Wei Y, Rothnagel JA, Smith R. Arginine methylation of hnRNP A2 does not directly govern its subcellular localization. PLoS One 2013; 8:e75669. [PMID: 24098712 PMCID: PMC3787039 DOI: 10.1371/journal.pone.0075669] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 08/16/2013] [Indexed: 11/18/2022] Open
Abstract
The hnRNP A/B paralogs A1, A2/B1 and A3 are key components of the nuclear 40S hnRNP core particles. Despite a high degree of sequence similarity, increasing evidence suggests they perform additional, functionally distinct roles in RNA metabolism. Here we identify and study the functional consequences of differential post-translational modification of hnRNPs A1, A2 and A3. We show that while arginine residues in the RGG box domain of hnRNP A1 and A3 are almost exhaustively, asymmetrically dimethylated, hnRNP A2 is dimethylated at only a single residue (Arg-254) and this modification is conserved across cell types. It has been suggested that arginine methylation regulates the nucleocytoplasmic distribution of hnRNP A/B proteins. However, we show that transfected cells expressing an A2R254A point mutant exhibit no difference in subcellular localization. Similarly, immunostaining and mass spectrometry of endogenous hnRNP A2 in transformed cells reveals a naturally-occurring pool of unmethylated protein but an exclusively nuclear pattern of localization. Our results suggest an alternative role for post-translational arginine methylation of hnRNPs and offer further evidence that the hnRNP A/B paralogs are not functionally redundant.
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Affiliation(s)
- Lexie R. Friend
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Michael J. Landsberg
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Amanda S. Nouwens
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Ying Wei
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Joseph A. Rothnagel
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, St. Lucia, Queensland, Australia
| | - Ross Smith
- School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
- * E-mail:
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34
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Dinh PX, Das A, Franco R, Pattnaik AK. Heterogeneous nuclear ribonucleoprotein K supports vesicular stomatitis virus replication by regulating cell survival and cellular gene expression. J Virol 2013; 87:10059-69. [PMID: 23843646 PMCID: PMC3754001 DOI: 10.1128/jvi.01257-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 06/30/2013] [Indexed: 11/20/2022] Open
Abstract
The heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a member of the family of hnRNPs and was recently shown in a genome-wide small interfering RNA (siRNA) screen to support vesicular stomatitis virus (VSV) growth. To decipher the role of hnRNP K in VSV infection, we conducted studies which suggest that the protein is required for VSV spreading. Virus binding to cells, entry, and nucleocapsid uncoating steps were not adversely affected in the absence of hnRNP K, whereas viral genome transcription and replication were reduced slightly. These results indicate that hnRNP K is likely involved in virus assembly and/or release from infected cells. Further studies showed that hnRNP K suppresses apoptosis of virus-infected cells, resulting in increased cell survival during VSV infection. The increased survival of the infected cells was found to be due to the suppression of proapoptotic proteins such as Bcl-XS and Bik in a cell-type-dependent manner. Additionally, depletion of hnRNP K resulted in not only significantly increased levels of T-cell-restricted intracellular antigen 1 (TIA1) but also switching of the expression of the two isoforms of the protein (TIA1a and TIA1b), both of which inhibited VSV replication. hnRNP K was also found to support expression of several cellular proteins known to be required for VSV infection. Overall, our studies demonstrate hnRNP K to be a multifunctional protein that supports VSV infection via its role(s) in suppressing apoptosis of infected cells, inhibiting the expression of antiviral proteins, and maintaining the expression of proteins required for the virus.
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Affiliation(s)
- Phat X. Dinh
- School of Veterinary Medicine and Biomedical Sciences
- Nebraska Center for Virology, University of Nebraska—Lincoln, Lincoln, Nebraska, USA
| | - Anshuman Das
- School of Veterinary Medicine and Biomedical Sciences
- Nebraska Center for Virology, University of Nebraska—Lincoln, Lincoln, Nebraska, USA
| | | | - Asit K. Pattnaik
- School of Veterinary Medicine and Biomedical Sciences
- Nebraska Center for Virology, University of Nebraska—Lincoln, Lincoln, Nebraska, USA
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35
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Erce MA, Abeygunawardena D, Low JKK, Hart-Smith G, Wilkins MR. Interactions affected by arginine methylation in the yeast protein-protein interaction network. Mol Cell Proteomics 2013; 12:3184-98. [PMID: 23918811 DOI: 10.1074/mcp.m113.031500] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Protein-protein interactions can be modulated by the methylation of arginine residues. As a means of testing this, we recently described a conditional two-hybrid system, based on the bacterial adenylate cyclase (BACTH) system. Here, we have used this conditional two-hybrid system to explore the effect of arginine methylation in modulating protein-protein interactions in a subset of the Saccharomyces cerevisiae arginine methylproteome network. Interactions between the yeast hub protein Npl3 and yeast proteins Air2, Ded1, Gbp2, Snp1, and Yra1 were first validated in the absence of methylation. The major yeast arginine methyltransferase Hmt1 was subsequently included in the conditional two-hybrid assay, initially to determine the degree of methylation that occurs. Proteins Snp1 and Yra1 were confirmed as Hmt1 substrates, with five and two novel arginine methylation sites mapped by ETD LC-MS/MS on these proteins, respectively. Proteins Ded1 and Gbp2, previously predicted but not confirmed as substrates of Hmt1, were also found to be methylated with five and seven sites mapped respectively. Air2 was found to be a novel substrate of Hmt1 with two sites mapped. Finally, we investigated the interactions of Npl3 with the five interaction partners in the presence of active Hmt1 and in the presence of Hmt1 with a G68R inactivation mutation. We found that the interaction between Npl3 and Air2, and Npl3 and Ded1, were significantly increased in the presence of active Hmt1; the interaction of Npl3 and Snp1 showed a similar degree of increase in interaction but this was not statistically significant. The interactions of Npl3 and Gbp2, along with Npl3 and Yra1, were not significantly increased or decreased by methylation. We conclude that methylarginine may be a widespread means by which the interactions of proteins are modulated.
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Affiliation(s)
- Melissa A Erce
- Systems Biology Laboratory, School of Biotechnology and Biomolecular Sciences, University of New South Wales, NSW 2052, Australia
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36
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Bentmann E, Haass C, Dormann D. Stress granules in neurodegeneration - lessons learnt from TAR DNA binding protein of 43 kDa and fused in sarcoma. FEBS J 2013; 280:4348-70. [DOI: 10.1111/febs.12287] [Citation(s) in RCA: 143] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Revised: 03/28/2013] [Accepted: 04/08/2013] [Indexed: 12/12/2022]
Affiliation(s)
- Eva Bentmann
- Adolf Butenandt Institute; Department of Biochemistry; Ludwig Maximilians University; Munich Germany
| | - Christian Haass
- Adolf Butenandt Institute; Department of Biochemistry; Ludwig Maximilians University; Munich Germany
- German Center for Neurodegenerative Diseases (DZNE); Munich Germany
- Munich Cluster for Systems Neurology (SyNergy); Munich Germany
| | - Dorothee Dormann
- Adolf Butenandt Institute; Department of Biochemistry; Ludwig Maximilians University; Munich Germany
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37
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Cyphert TJ, Suchanek AL, Griffith BN, Salati LM. Starvation actively inhibits splicing of glucose-6-phosphate dehydrogenase mRNA via a bifunctional ESE/ESS element bound by hnRNP K. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:905-15. [PMID: 23631859 DOI: 10.1016/j.bbagrm.2013.04.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 04/17/2013] [Accepted: 04/22/2013] [Indexed: 12/26/2022]
Abstract
Regulated expression of glucose-6-phosphate dehydrogenase (G6PD) is due to changes in the rate of pre-mRNA splicing and not changes in its transcription. Starvation alters pre-mRNA splicing by decreasing the rate of intron removal, leading to intron retention and a decrease in the accumulation of mature mRNA. A regulatory element within exon 12 of G6PD pre-mRNA controls splicing efficiency. Starvation caused an increase in the expression of heterogeneous nuclear ribonucleoprotein (hnRNP) K protein and this increase coincided with the increase in the binding of hnRNP K to the regulatory element and a decrease in the expression of G6PD mRNA. HnRNP K bound to two C-rich motifs forming an ESS within exon 12. Overexpression of hnRNP K decreased the splicing and expression of G6PD mRNA, while siRNA-mediated depletion of hnRNP K caused an increase in the splicing and expression of G6PD mRNA. Binding of hnRNP K to the regulatory element was enhanced in vivo by starvation coinciding with a decrease in G6PD mRNA. HnRNP K binding to the C-rich motifs blocked binding of serine-arginine rich, splicing factor 3 (SRSF3), a splicing enhancer. Thus hnRNP K is a nutrient regulated splicing factor responsible for the inhibition of the splicing of G6PD during starvation.
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Affiliation(s)
- T J Cyphert
- Department of Biochemistry, West Virginia University, Morgantown, WV 26506, USA
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38
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Abstract
Post-transcriptional control of gene expression is crucial for the control of cellular differentiation. Erythroid precursor cells loose their organelles in a timely controlled manner during terminal maturation to functional erythrocytes. Extrusion of the nucleus precedes the release of young reticulocytes into the blood stream. The degradation of mitochondria is initiated by reticulocyte 15-lipoxygenase (r15-LOX) in mature reticulocytes. At that terminal stage the release of r15-LOX mRNA from its translational silenced state induces the synthesis of r15-LOX. Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a key regulator of r15-LOX mRNA translation. HnRNP K that binds to the differentiation control element (DICE) in the 3′ untranslated region (UTR) inhibits r15-LOX mRNA translation initiation. During erythroid cell maturation, activation of r15-LOX mRNA translation is mediated by post-translational modifications of hnRNP K and a decrease of the hnRNP K level. To further elucidate its function in the post-transcriptional control of gene expression, we investigated hnRNP K degradation employing an inducible erythroid cell system that recapitulates both nuclear extrusion and the timely controlled degradation of mitochondria, mediated by the activation of r15-LOX synthesis. Interestingly, we detected a specific N-terminal cleavage intermediate of hnRNP K lacking DICE-binding activity that appeared during erythroid differentiation and puromycin-induced apoptosis. Employing mass spectrometry and enzymatic analyses, we identified Caspase-3 as the enzyme that cleaves hnRNP K specifically. In vitro studies revealed that cleavage by Caspase-3 at amino acids (aa) D334-G335 removes the C-terminal hnRNP K homology (KH) domain 3 that confers binding of hnRNP K to the DICE. Our data suggest that the processing of hnRNP K by Caspase-3 provides a save-lock mechanism for its timely release from the r15-LOX mRNA silencing complex and activation of r15-LOX mRNA synthesis in erythroid cell differentiation.
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39
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Gui S, Wooderchak-Donahue WL, Zang T, Chen D, Daly MP, Zhou ZS, Hevel JM. Substrate-Induced Control of Product Formation by Protein Arginine Methyltransferase 1. Biochemistry 2012; 52:199-209. [DOI: 10.1021/bi301283t] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Shanying Gui
- Chemistry
and Biochemistry Department, Utah State University, 0300 Old Main Hill, Logan, Utah
84322, United States
| | | | - Tianzhu Zang
- The
Barnett Institute of Chemical
and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston,
Massachusetts 02115-5000, United States
| | - Dong Chen
- Synthetic Bio-manufacturing Institute, Utah State University, 620 East 1600 North, Suite 226,
Logan, Utah 84341, United States
| | - Michael P. Daly
- Waters Corporation, 100 Cummings Center,
Suite 407N, Beverly, Massachusetts 01915,
United States
| | - Zhaohui Sunny Zhou
- The
Barnett Institute of Chemical
and Biological Analysis, Department of Chemistry and Chemical Biology, Northeastern University, 360 Huntington Avenue, Boston,
Massachusetts 02115-5000, United States
| | - Joan M. Hevel
- Chemistry
and Biochemistry Department, Utah State University, 0300 Old Main Hill, Logan, Utah
84322, United States
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40
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Lee YJ, Hsieh WY, Chen LY, Li C. Protein arginine methylation of SERBP1 by protein arginine methyltransferase 1 affects cytoplasmic/nuclear distribution. J Cell Biochem 2012; 113:2721-8. [PMID: 22442049 DOI: 10.1002/jcb.24151] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Protein arginine methylation regulates a broad array of cellular processes. SERBP1 implicated in tumor progression through its putative involvement in the plaminogen activator protease cascade, is an RNA-binding protein containing an RG-rich domain and an RGG box domain that might be methylated by protein arginine N-methyltransferases (PRMTs). Asymmetric dimethylarginine (aDMA) was detected in SERBP1 and an indirect methyltransferase inhibitor adenosine dialdehyde (AdOx) significantly reduced the methylation signals. Arginines in the middle RG and C-terminal RGG region of SERBP1 are methylated based on the analyses of different deletion constructs. The predominant type I protein arginine methyltransferase PRMT1 co-immunoprecipitated with SERBP1 and the level of bound PRMT1 decreased upon the addition of AdOx. Recombinant PRMT1 methylated SERBP1 and knockdown of PRMT1 significantly reduced the aDMA level of SERBP1, indicating that SERBP1 is specifically methylated by PRMT1. Immunofluorescent analyses of endogenous SERBP1 showed predominant cytoplasmic localization of SERBP1. Treatment of AdOx or PRMT1 siRNA increased the nuclear localization of SERBP1. Analyses of different deletions indicated that the middle RG region is important for the nuclear localization while both N- and C- terminus are required for nuclear export. Low methylation of the C-terminal RGG region also favors nuclear localization. In conclusion, the RG-rich and RGG box of SERBP1 is asymmetrically dimethylated by PRMT1 and the modification affects protein interaction and intracellular localization of the protein. These findings provide the basis for dissecting the roles of SERBP1.
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Affiliation(s)
- Yu-Jen Lee
- Institute of Biochemistry and Biotechnology, Chung Shan Medical University, Taichung, Taiwan
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41
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Arginine methylation next to the PY-NLS modulates Transportin binding and nuclear import of FUS. EMBO J 2012; 31:4258-75. [PMID: 22968170 PMCID: PMC3501225 DOI: 10.1038/emboj.2012.261] [Citation(s) in RCA: 241] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Accepted: 08/17/2012] [Indexed: 12/13/2022] Open
Abstract
Fused in sarcoma (FUS) is a nuclear protein that carries a proline-tyrosine nuclear localization signal (PY-NLS) and is imported into the nucleus via Transportin (TRN). Defects in nuclear import of FUS have been implicated in neurodegeneration, since mutations in the PY-NLS of FUS cause amyotrophic lateral sclerosis (ALS). Moreover, FUS is deposited in the cytosol in a subset of frontotemporal lobar degeneration (FTLD) patients. Here, we show that arginine methylation modulates nuclear import of FUS via a novel TRN-binding epitope. Chemical or genetic inhibition of arginine methylation restores TRN-mediated nuclear import of ALS-associated FUS mutants. The unmethylated arginine-glycine-glycine domain preceding the PY-NLS interacts with TRN and arginine methylation in this domain reduces TRN binding. Inclusions in ALS-FUS patients contain methylated FUS, while inclusions in FTLD-FUS patients are not methylated. Together with recent findings that FUS co-aggregates with two related proteins of the FET family and TRN in FTLD-FUS but not in ALS-FUS, our study provides evidence that these two diseases may be initiated by distinct pathomechanisms and implicates alterations in arginine methylation in pathogenesis.
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42
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Binding of the heterogeneous ribonucleoprotein K (hnRNP K) to the Epstein-Barr virus nuclear antigen 2 (EBNA2) enhances viral LMP2A expression. PLoS One 2012; 7:e42106. [PMID: 22879910 PMCID: PMC3411732 DOI: 10.1371/journal.pone.0042106] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2012] [Accepted: 07/02/2012] [Indexed: 12/31/2022] Open
Abstract
The Epstein-Barr Virus (EBV) -encoded EBNA2 protein, which is essential for the in vitro transformation of B-lymphocytes, interferes with cellular processes by binding to proteins via conserved sequence motifs. Its Arginine-Glycine (RG) repeat element contains either symmetrically or asymmetrically di-methylated arginine residues (SDMA and ADMA, respectively). EBNA2 binds via its SDMA-modified RG-repeat to the survival motor neurons protein (SMN) and via the ADMA-RG-repeat to the NP9 protein of the human endogenous retrovirus K (HERV-K (HML-2) Type 1). The hypothesis of this work was that the methylated RG-repeat mimics an epitope shared with cellular proteins that is used for interaction with target structures. With monoclonal antibodies against the modified RG-repeat, we indeed identified cellular homologues that apparently have the same surface structure as methylated EBNA2. With the SDMA-specific antibodies, we precipitated the Sm protein D3 (SmD3) which, like EBNA2, binds via its SDMA-modified RG-repeat to SMN. With the ADMA-specific antibodies, we precipitated the heterogeneous ribonucleoprotein K (hnRNP K). Specific binding of the ADMA- antibody to hnRNP K was demonstrated using E. coli expressed/ADMA-methylated hnRNP K. In addition, we show that EBNA2 and hnRNP K form a complex in EBV- infected B-cells. Finally, hnRNP K, when co-expressed with EBNA2, strongly enhances viral latent membrane protein 2A (LMP2A) expression by an unknown mechanism as we did not detect a direct association of hnRNP K with DNA-bound EBNA2 in gel shift experiments. Our data support the notion that the methylated surface of EBNA2 mimics the surface structure of cellular proteins to interfere with or co-opt their functional properties.
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43
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Rajyaguru P, Parker R. RGG motif proteins: modulators of mRNA functional states. Cell Cycle 2012; 11:2594-9. [PMID: 22767211 PMCID: PMC3873214 DOI: 10.4161/cc.20716] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
A recent report demonstrates that a subset of RGG-motif proteins can bind translation initiation factor eIF4G and repress mRNA translation. This adds to the growing number of roles RGG-motif proteins play in modulating transcription, splicing, mRNA export and now translation. Herein, we review the nature and breadth of functions of RGG-motif proteins. In addition, the interaction of some RGG-motif proteins and other translation repressors with eIF4G highlights the role of eIF4G as a general modulator of mRNA function and not solely as a translation initiation factor.
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Affiliation(s)
- Purusharth Rajyaguru
- Department of Molecular and Cellular Biology and Howard Hughes Medical Institute, The University of Arizona, Tucson, Tucson, AZ, USA
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44
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Kölbel K, Ihling C, Kühn U, Neundorf I, Otto S, Stichel J, Robaa D, Beck-Sickinger AG, Sinz A, Wahle E. Peptide Backbone Conformation Affects the Substrate Preference of Protein Arginine Methyltransferase I. Biochemistry 2012; 51:5463-75. [DOI: 10.1021/bi300373b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Knut Kölbel
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Strasse
3, 06120 Halle, Germany
| | - Christian Ihling
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle, Germany
| | - Uwe Kühn
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Strasse
3, 06120 Halle, Germany
| | - Ines Neundorf
- Institute of Biochemistry, University of Leipzig, Brüderstrasse 34, 04103
Leipzig, Germany
| | - Silke Otto
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Strasse
3, 06120 Halle, Germany
| | - Jan Stichel
- Institute of Biochemistry, University of Leipzig, Brüderstrasse 34, 04103
Leipzig, Germany
| | - Dina Robaa
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle, Germany
| | | | - Andrea Sinz
- Institute of Pharmacy, Martin Luther University Halle-Wittenberg, Wolfgang-Langenbeck-Strasse 4, 06120 Halle, Germany
| | - Elmar Wahle
- Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Strasse
3, 06120 Halle, Germany
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45
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Willnow S, Martin M, Lüscher B, Weinhold E. A Selenium-Based Click AdoMet Analogue for Versatile Substrate Labeling with Wild-Type Protein Methyltransferases. Chembiochem 2012; 13:1167-73. [DOI: 10.1002/cbic.201100781] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2011] [Indexed: 11/12/2022]
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46
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Erce MA, Pang CNI, Hart-Smith G, Wilkins MR. The methylproteome and the intracellular methylation network. Proteomics 2012; 12:564-86. [DOI: 10.1002/pmic.201100397] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Revised: 09/23/2011] [Accepted: 10/17/2011] [Indexed: 12/30/2022]
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47
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Chiou YY, Fu SL, Lin WJ, Lin CH. Proteomics analysis of in vitro protein methylation during Src-induced transformation. Electrophoresis 2012; 33:451-61. [DOI: 10.1002/elps.201100280] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/14/2011] [Accepted: 10/07/2011] [Indexed: 11/11/2022]
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48
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Fronz K, Güttinger S, Burkert K, Kühn U, Stöhr N, Schierhorn A, Wahle E. Arginine methylation of the nuclear poly(a) binding protein weakens the interaction with its nuclear import receptor, transportin. J Biol Chem 2011; 286:32986-94. [PMID: 21808065 PMCID: PMC3190935 DOI: 10.1074/jbc.m111.273912] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 07/28/2011] [Indexed: 11/06/2022] Open
Abstract
The nuclear poly(A) binding protein, PABPN1, promotes mRNA polyadenylation in the cell nucleus by increasing the processivity of poly(A) polymerase and contributing to poly(A) tail length control. In its C-terminal domain, the protein carries 13 arginine residues that are all asymmetrically dimethylated. The function of this modification in PABPN1 has been unknown. Part of the methylated domain serves as nuclear localization signal, binding the import receptor transportin. Here we report that arginine methylation weakens the affinity of PABPN1 for transportin. Recombinant, unmethylated PABPN1 binds more strongly to transportin than its methylated counterpart from mammalian tissue, and in vitro methylation reduces the affinity. Transportin and RNA compete for binding to PABPN1. Methylation favors RNA binding. Transportin also inhibits in vitro methylation of the protein. Finally, a peptide corresponding to the nuclear localization signal of PABPN1 competes with transportin-dependent nuclear import of the protein in a permeabilized cell assay and does so less efficiently when it is methylated. We hypothesize that transportin binding might delay methylation of PABPN1 until after nuclear import. In the nucleus, arginine methylation may favor the transition of PABPN1 to the competing ligand RNA and serve to reduce the risk of the protein being reexported to the cytoplasm by transportin.
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Affiliation(s)
- Katharina Fronz
- From the Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Stefan Güttinger
- the Institute of Biochemistry, Swiss Federal Institute of Technology (ETH Zürich), Schafmattstrasse 18, 8093 Zürich, Switzerland, and
| | - Kerstin Burkert
- From the Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Uwe Kühn
- From the Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Nadine Stöhr
- the Section for Molecular Cell Biology, Department of Medicine, Martin Luther University Halle-Wittenberg, 06097 Halle, Germany
| | - Angelika Schierhorn
- From the Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
| | - Elmar Wahle
- From the Institute of Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, 06099 Halle, Germany
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49
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Pak ML, Lakowski TM, Thomas D, Vhuiyan MI, Hüsecken K, Frankel A. A protein arginine N-methyltransferase 1 (PRMT1) and 2 heteromeric interaction increases PRMT1 enzymatic activity. Biochemistry 2011; 50:8226-40. [PMID: 21851090 DOI: 10.1021/bi200644c] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Protein arginine N-methyltransferases (PRMTs) act in signaling pathways and gene expression by methylating arginine residues within target proteins. PRMT1 is responsible for most cellular arginine methylation activity and can work independently or in collaboration with other PRMTs. In this study, we demonstrate a direct interaction between PRMT1 and PRMT2 using co-immunoprecipitation, bimolecular fluorescence complementation, and enzymatic assays. As a result of this interaction, PRMT2 stimulated PRMT1 activity, affecting its apparent V(max) and K(M) values in vitro and increasing the production of methylarginines in cells. Active site mutations and regional deletions from PRMT1 and -2 were also investigated, which demonstrated that complex formation required full-length, active PRMT1. Although the inhibition of methylation by adenosine dialdehyde prevented the interaction between PRMT1 and -2, it did not prevent the interaction between PRMT1 and a truncation mutant of PRMT2 lacking its Src homology 3 (SH3) domain. This result suggests that the SH3 domain may mediate an interaction between PRMT1 and -2 in a methylation-dependent fashion. On the basis of our findings, we propose that PRMT1 serves as the major methyltransferase in cells by forming higher-order oligomers with itself, PRMT2, and possibly other PRMTs.
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Affiliation(s)
- Magnolia L Pak
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
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50
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Aurora-A phosphorylates hnRNPK and disrupts its interaction with p53. FEBS Lett 2011; 585:2671-5. [PMID: 21821029 DOI: 10.1016/j.febslet.2011.07.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Revised: 07/07/2011] [Accepted: 07/21/2011] [Indexed: 01/18/2023]
Abstract
Amplification of Aurora-A, encoding a cell cycle-regulating kinase, has been reported in human cancers. Although Aurora-A is known to directly phosphorylate and down-regulate p53, the detailed mechanism remains unclear. Here we show that Aurora-A phosphorylates hnRNPK, a transcriptional coactivator of p53, on serine 379. This phosphorylation does not affect the post-transcriptional activity or cellular localization of hnRNPK, but disrupts its interaction with p53. Inverse correlation between Aurora-A activity and hnRNPK-p53 interaction was further demonstrated in DNA-damaged cells. Our results provide an alternative mechanism, whereby via phosphorylating hnRNPK Aurora-A participates in regulating p53 activity during DNA damage.
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