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Huang S, Hu J, Hu M, Hou Y, Zhang B, Liu J, Liu X, Chen Z, Wang L. Cooperation between SIX1 and DHX9 transcriptionally regulates integrin-focal adhesion signaling mediated metastasis and sunitinib resistance in KIRC. Oncogene 2024; 43:2951-2969. [PMID: 39174859 DOI: 10.1038/s41388-024-03126-w] [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: 02/11/2024] [Revised: 08/02/2024] [Accepted: 08/06/2024] [Indexed: 08/24/2024]
Abstract
High invasive capacity and acquired tyrosine kinase inhibitors (TKI) resistance of kidney renal clear cell carcinoma (KIRC) cells remain obstacles to prolonging the survival time of patients with advanced KIRC. In the present study, we reported that sine oculis homeobox 1 (SIX1) was upregulated in sunitinib-resistant KIRC cells and metastatic KIRC tissues. Subsequently, we found that SIX1 mediated metastasis and sunitinib resistance via Focal adhesion (FA) signaling, and knockdown of SIX1 enhanced the antitumor efficiency of sunitinib in KIRC. Mechanistically, Integrin subunit beta 1 (ITGB1), an upstream gene of FA signaling, was a direct transcriptional target of SIX1. In addition, we showed that DExH-box helicase 9 (DHX9) was an important mediator for SIX1-induced ITGB1 transcription, and silencing the subunits of SIX1/DHX9 complex significantly reduced transcription of ITGB1. Downregulation of SIX1 attenuated nuclear translocation of DHX9 and abrogated the binding of DHX9 to ITGB1 promoter. Collectively, our results unveiled a new signal axis SIX1/ITGB1/FAK in KIRC and identified a novel therapeutic strategy for metastatic KIRC patients.
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Affiliation(s)
- Shiyu Huang
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Central Laboratory, Renmin Hospital of Wuhan University, 430060, Wuhan, Hubei, China
| | - Juncheng Hu
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Min Hu
- Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Yanguang Hou
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Banghua Zhang
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Hubei Key Laboratory of Digestive System Disease, Wuhan, 430060, China
| | - Jiachen Liu
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China
| | - Xiuheng Liu
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
| | - Zhiyuan Chen
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
| | - Lei Wang
- Department of Urology, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
- Institute of Urologic Disease, Renmin Hospital of Wuhan University, Wuhan, 430060, Hubei, China.
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2
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Cao Y, Wu J, Hu Y, Chai Y, Song J, Duan J, Zhang S, Xu X. Virus-induced lncRNA-BTX allows viral replication by regulating intracellular translocation of DHX9 and ILF3 to induce innate escape. Cell Rep 2023; 42:113262. [PMID: 37864796 DOI: 10.1016/j.celrep.2023.113262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 05/26/2023] [Accepted: 09/28/2023] [Indexed: 10/23/2023] Open
Abstract
The roles of long noncoding RNA (lncRNA) and RNA-binding proteins (RBPs) in antiviral innate response warrant further investigation. Here, we identify an lncRNA, termed lncRNA-BTX (between Tbk1 and Xpot), which is upregulated upon viral infection via an IRF3-type I interferon-independent pathway, promoting viral innate immune escape. Deletion of lncRNA-BTX in cells or mice significantly reduces viral load in vitro or in vivo, respectively. Mechanistically, lncRNA-BTX strengthens the interactions between DHX9 or ILF3 (two RBPs that have opposite functions in regulating the replication of RNA virus) and their respective partner, JMJD6 or ILF2, which regulates intracellular translocations of DHX9 and ILF3 from the nucleus to the cytoplasm. Put simply, lncRNA-BTX facilitates DHX9's return to the cytoplasm and retains ILF3 within the nucleus, promoting viral replication. This work unveils a strategy developed by the virus to bypass host innate immunity, thus providing a potential target for antiviral therapeutics.
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Affiliation(s)
- Yang Cao
- Frontier Research Center for Cell Response, Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Jiacheng Wu
- Department of Immunology, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Ye Hu
- Frontier Research Center for Cell Response, Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Yangyang Chai
- Department of Immunology, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Jiaying Song
- Department of Immunology, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Jiaqi Duan
- Department of Immunology, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China
| | - Song Zhang
- Frontier Research Center for Cell Response, Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China
| | - Xiaoqing Xu
- Frontier Research Center for Cell Response, Institute of Immunology, College of Life Sciences, Nankai University, Tianjin 300071, China; Department of Immunology, Institute of Basic Medical Sciences, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing 100005, China.
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3
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Wang J, Wang Z, Inuzuka H, Wei W, Liu J. PRMT1 methylates METTL14 to modulate its oncogenic function. Neoplasia 2023; 42:100912. [PMID: 37269817 PMCID: PMC10248872 DOI: 10.1016/j.neo.2023.100912] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 06/05/2023]
Abstract
N6-methyladenosine (m6A), the most abundant mRNA modification in mammalian cells, is responsible for mRNA stability and alternative splicing. The METTL3-METTL14-WTAP complex is the only methyltransferase for the m6A modification. Thus, regulation of its enzymatic activity is critical for the homeostasis of mRNA m6A levels in cells. However, relatively little is known about the upstream regulation of the METTL3-METTL14-WTAP complex, especially at the post-translational modification level. The C-terminal RGG repeats of METTL14 are critical for RNA binding. Therefore, modifications on these residues may play a regulatory role in its function. Arginine methylation is a post-translational modification catalyzed by protein arginine methyltransferases (PRMTs), among which PRMT1 preferentially methylates protein substrates with an arginine/glycine-rich motif. In addition, PRMT1 functions as a key regulator of mRNA alternative splicing, which is associated with m6A modification. To this end, we report that PRMT1 promotes the asymmetric methylation of two major arginine residues at the C-terminus of METTL14, and the reader protein SPF30 recognizes this modification. Functionally, PRMT1-mediated arginine methylation on METTL14 is likely essential for its function in catalyzing the m6A modification. Moreover, arginine methylation of METTL14 promotes cell proliferation that is antagonized by the PRMT1 inhibitor MS023. These results indicate that PRMT1 likely regulates m6A modification and promotes tumorigenesis through arginine methylation at the C-terminus of METTL14.
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Affiliation(s)
- Jingchao Wang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Zhen Wang
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Hiroyuki Inuzuka
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - Wenyi Wei
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
| | - Jing Liu
- Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA.
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Dane TL, Gill AL, Vieira FG, Denton KR. Reduced C9orf72 expression exacerbates polyGR toxicity in patient iPSC-derived motor neurons and a Type I protein arginine methyltransferase inhibitor reduces that toxicity. Front Cell Neurosci 2023; 17:1134090. [PMID: 37138766 PMCID: PMC10149854 DOI: 10.3389/fncel.2023.1134090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Accepted: 03/27/2023] [Indexed: 05/05/2023] Open
Abstract
Introduction Intronic repeat expansions in the C9orf72 gene are the most frequent known single genetic causes of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). These repeat expansions are believed to result in both loss-of-function and toxic gain-of-function. Gain-of-function results in the production of toxic arginine-rich dipeptide repeat proteins (DPRs), namely polyGR and polyPR. Small-molecule inhibition of Type I protein arginine methyltransferases (PRMTs) has been shown to protect against toxicity resulting from polyGR and polyPR challenge in NSC-34 cells and primary mouse-derived spinal neurons, but the effect in human motor neurons (MNs) has not yet been explored. Methods To study this, we generated a panel of C9orf72 homozygous and hemizygous knockout iPSCs to examine the contribution of C9orf72 loss-of-function toward disease pathogenesis. We differentiated these iPSCs into spinal motor neurons (sMNs). Results We found that reduced levels of C9orf72 exacerbate polyGR15 toxicity in a dose-dependent manner. Type I PRMT inhibition was able to partially rescue polyGR15 toxicity in both wild-type and C9orf72-expanded sMNs. Discussion This study explores the interplay of loss-of-function and gain-of-function toxicity in C9orf72 ALS. It also implicates type I PRMT inhibitors as a possible modulator of polyGR toxicity.
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Ren X, Wang D, Zhang G, Zhou T, Wei Z, Yang Y, Zheng Y, Lei X, Tao W, Wang A, Li M, Flavell RA, Zhu S. Nucleic DHX9 cooperates with STAT1 to transcribe interferon-stimulated genes. SCIENCE ADVANCES 2023; 9:eadd5005. [PMID: 36735791 PMCID: PMC9897671 DOI: 10.1126/sciadv.add5005] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/05/2023] [Indexed: 06/13/2023]
Abstract
RNA helicase DHX9 has been extensively characterized as a transcriptional regulator, which is consistent with its mostly nucleic localization. It is also involved in recognizing RNA viruses in the cytoplasm. However, there is no in vivo data to support the antiviral role of DHX9; meanwhile, as a nuclear protein, if and how nucleic DHX9 promotes antiviral immunity remains largely unknown. Here, we generated myeloid-specific and hepatocyte-specific DHX9 knockout mice and confirmed that DHX9 is crucial for host resistance to RNA virus infections in vivo. By additional knockout MAVS or STAT1 in DHX9-deficient mice, we demonstrated that nucleic DHX9 plays a positive role in regulating interferon-stimulated gene (ISG) expression downstream of type I interferon. Mechanistically, upon interferon stimulation, DHX9 is directly bound to STAT1 and recruits Pol II to the ISG promoter region to participate in STAT1-mediated transcription of ISGs. Collectively, these findings uncover an important role for nucleic DHX9 in antiviral immunity.
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Affiliation(s)
- Xingxing Ren
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
- Department of Gastroenterology, Third Affiliated Hospital of Guangzhou Medical University, 510145 Guangzhou, China
| | - Decai Wang
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Guorong Zhang
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Tingyue Zhou
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Zheng Wei
- Department of Immunobiology, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
| | - Yi Yang
- Department of Immunobiology, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
| | - Yunjiang Zheng
- Department of Immunobiology, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
| | - Xuqiu Lei
- Department of Immunobiology, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
| | - Wanyin Tao
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Anmin Wang
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
| | - Mingsong Li
- Department of Gastroenterology, Third Affiliated Hospital of Guangzhou Medical University, 510145 Guangzhou, China
| | - Richard A. Flavell
- Department of Immunobiology, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
- Howard Hughes Medical Institute, Yale University School of Medicine, 300 Cedar Street, New Haven, CT 06510, USA
| | - Shu Zhu
- Department of Digestive Disease, Division of Life Sciences and Medicine, The First Affiliated Hospital of University of Science and Technology of China, University of Science and Technology of China, 230001 Hefei, China
- Institute of Immunology and the CAS Key Laboratory of Innate Immunity and Chronic Disease, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei 230027, China
- School of Data Science, University of Science and Technology of China, Hefei 230026, China
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China
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6
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Tang S, Cao Y, Cai Z, Nie X, Ruan J, Zhou Z, Ruan G, Zhu Z, Han W, Ding C. The lncRNA PILA promotes NF-κB signaling in osteoarthritis by stimulating the activity of the protein arginine methyltransferase PRMT1. Sci Signal 2022; 15:eabm6265. [PMID: 35609127 DOI: 10.1126/scisignal.abm6265] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Inflammatory cytokine-induced activation of nuclear factor κB (NF-κB) signaling plays a critical role in the pathogenesis of osteoarthritis (OA). We identified PILA as a long noncoding RNA (lncRNA) that enhances NF-κB signaling and OA. The abundance of PILA was increased in damaged cartilage from patients with OA and in human articular chondrocytes stimulated with the proinflammatory cytokine tumor necrosis factor (TNF). Knockdown of PILA inhibited TNF-induced NF-κB signaling, extracellular matrix catabolism, and apoptosis in chondrocytes, whereas ectopic expression of PILA promoted NF-κB signaling and matrix degradation. PILA promoted PRMT1-mediated arginine methylation of DExH-box helicase 9 (DHX9), leading to an increase in the transcription of the gene encoding transforming growth factor β-activated kinase 1 (TAK1), an upstream activator of NF-κB signaling. Furthermore, intra-articular injection of an adenovirus vector encoding PILA triggered spontaneous cartilage loss and exacerbated posttraumatic OA in mice. This study provides insight into the regulation of NF-κB signaling in OA and identifies a potential therapeutic target for this disease.
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Affiliation(s)
- Su'an Tang
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China.,Centre of Orthopedics, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Yumei Cao
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Zhaopeng Cai
- Department of Orthopedics, Eighth Affiliated Hospital, Sun Yat-sen University, 518033 Shenzhen, Guangdong, China
| | - Xiaoyu Nie
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Jianzhao Ruan
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Zuoqing Zhou
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China.,Department of Orthopedics, First Affiliated Hospital, Shaoyang University, 422099 Shaoyang, Hunan, China
| | - Guangfeng Ruan
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Zhaohua Zhu
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China.,Centre of Orthopedics, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Weiyu Han
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China.,Centre of Orthopedics, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China
| | - Changhai Ding
- Clinical Research Centre, Zhujiang Hospital, Southern Medical University, 510280 Guangzhou, Guangdong, China.,Menzies Institute for Medical Research, University of Tasmania, 7000 Hobart, Tasmania, Australia
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7
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Teixeira CSS, Sousa SF. Current Status of the Use of Multifunctional Enzymes as Anti-Cancer Drug Targets. Pharmaceutics 2021; 14:pharmaceutics14010010. [PMID: 35056904 PMCID: PMC8780674 DOI: 10.3390/pharmaceutics14010010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/06/2021] [Accepted: 12/17/2021] [Indexed: 12/23/2022] Open
Abstract
Fighting cancer is one of the major challenges of the 21st century. Among recently proposed treatments, molecular-targeted therapies are attracting particular attention. The potential targets of such therapies include a group of enzymes that possess the capability to catalyze at least two different reactions, so-called multifunctional enzymes. The features of such enzymes can be used to good advantage in the development of potent selective inhibitors. This review discusses the potential of multifunctional enzymes as anti-cancer drug targets along with the current status of research into four enzymes which by their inhibition have already demonstrated promising anti-cancer effects in vivo, in vitro, or both. These are PFK-2/FBPase-2 (involved in glucose homeostasis), ATIC (involved in purine biosynthesis), LTA4H (involved in the inflammation process) and Jmjd6 (involved in histone and non-histone posttranslational modifications). Currently, only LTA4H and PFK-2/FBPase-2 have inhibitors in active clinical development. However, there are several studies proposing potential inhibitors targeting these four enzymes that, when used alone or in association with other drugs, may provide new alternatives for preventing cancer cell growth and proliferation and increasing the life expectancy of patients.
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Affiliation(s)
- Carla S. S. Teixeira
- Associate Laboratory i4HB, Faculty of Medicine, Institute for Health and Bioeconomy, University of Porto, 4050-313 Porto, Portugal;
- UCIBIO—Applied Molecular Biosciences Unit, BioSIM—Department of Biomedicine, Faculty of Medicine, University of Porto, 4051-401 Porto, Portugal
| | - Sérgio F. Sousa
- Associate Laboratory i4HB, Faculty of Medicine, Institute for Health and Bioeconomy, University of Porto, 4050-313 Porto, Portugal;
- UCIBIO—Applied Molecular Biosciences Unit, BioSIM—Department of Biomedicine, Faculty of Medicine, University of Porto, 4051-401 Porto, Portugal
- Correspondence:
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Semmelink MFW, Steen A, Veenhoff LM. Measuring and Interpreting Nuclear Transport in Neurodegenerative Disease-The Example of C9orf72 ALS. Int J Mol Sci 2021; 22:9217. [PMID: 34502125 PMCID: PMC8431710 DOI: 10.3390/ijms22179217] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/13/2021] [Accepted: 08/18/2021] [Indexed: 11/25/2022] Open
Abstract
Transport from and into the nucleus is essential to all eukaryotic life and occurs through the nuclear pore complex (NPC). There are a multitude of data supporting a role for nuclear transport in neurodegenerative diseases, but actual transport assays in disease models have provided diverse outcomes. In this review, we summarize how nuclear transport works, which transport assays are available, and what matters complicate the interpretation of their results. Taking a specific type of ALS caused by mutations in C9orf72 as an example, we illustrate these complications, and discuss how the current data do not firmly answer whether the kinetics of nucleocytoplasmic transport are altered. Answering this open question has far-reaching implications, because a positive answer would imply that widespread mislocalization of proteins occurs, far beyond the reported mislocalization of transport reporters, and specific proteins such as FUS, or TDP43, and thus presents a challenge for future research.
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Affiliation(s)
| | | | - Liesbeth M. Veenhoff
- European Research Institute for the Biology of Ageing, University of Groningen, University Medical Center Groningen, 9713 AV Groningen, The Netherlands; (M.F.W.S.); (A.S.)
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9
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Yuan W, Al-Hadid Q, Wang Z, Shen L, Cho H, Wu X, Yang Y. TDRD3 promotes DHX9 chromatin recruitment and R-loop resolution. Nucleic Acids Res 2021; 49:8573-8591. [PMID: 34329467 PMCID: PMC8421139 DOI: 10.1093/nar/gkab642] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 06/14/2021] [Accepted: 07/19/2021] [Indexed: 11/12/2022] Open
Abstract
R-loops, which consist of a DNA/RNA hybrid and a displaced single-stranded DNA (ssDNA), are increasingly recognized as critical regulators of chromatin biology. R-loops are particularly enriched at gene promoters, where they play important roles in regulating gene expression. However, the molecular mechanisms that control promoter-associated R-loops remain unclear. The epigenetic ‘reader’ Tudor domain-containing protein 3 (TDRD3), which recognizes methylarginine marks on histones and on the C-terminal domain of RNA polymerase II, was previously shown to recruit DNA topoisomerase 3B (TOP3B) to relax negatively supercoiled DNA and prevent R-loop formation. Here, we further characterize the function of TDRD3 in R-loop metabolism and introduce the DExH-box helicase 9 (DHX9) as a novel interaction partner of the TDRD3/TOP3B complex. TDRD3 directly interacts with DHX9 via its Tudor domain. This interaction is important for recruiting DHX9 to target gene promoters, where it resolves R-loops in a helicase activity-dependent manner to facilitate gene expression. Additionally, TDRD3 also stimulates the helicase activity of DHX9. This stimulation relies on the OB-fold of TDRD3, which likely binds the ssDNA in the R-loop structure. Thus, DHX9 functions together with TOP3B to suppress promoter-associated R-loops. Collectively, these findings reveal new functions of TDRD3 and provide important mechanistic insights into the regulation of R-loop metabolism.
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Affiliation(s)
- Wei Yuan
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Qais Al-Hadid
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Zhihao Wang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Lei Shen
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Hyejin Cho
- Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Xiwei Wu
- Department of Molecular and Cellular Biology, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
| | - Yanzhong Yang
- Department of Cancer Genetics and Epigenetics, Beckman Research Institute, City of Hope National Cancer Center, Duarte, CA 91010, USA
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10
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Wei Q, Geng J, Chen Y, Lin H, Wang J, Fang Z, Wang F, Zhang Z. Structure and function of DEAH-box helicase 32 and its role in cancer. Oncol Lett 2021; 21:382. [PMID: 33777205 PMCID: PMC7988694 DOI: 10.3892/ol.2021.12643] [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: 08/16/2020] [Accepted: 12/23/2020] [Indexed: 11/06/2022] Open
Abstract
DEAH-box helicase 32 (DHX32) is an RNA helicase with unique structural characteristics that is involved in numerous biological processes associated with RNA, including ribosome biosynthesis, transcription, mRNA splicing and translation. Increasing evidence suggests that abnormal DHX32 expression contributes to cancer initiation and development, due to dysregulated cell proliferation, differentiation, apoptosis and other processes. In the current review, the discovery, structure and function of DHX32, as well as the association between abnormal DHX32 expression and tumors are discussed. DHX32 expression is downregulated in acute lymphoblastic leukemia, but upregulated in solid tumors, including colorectal and breast cancer. Furthermore, DHX32 expression levels are associated with the pathological and clinical features of the cancer. Therefore, DHX32 may serve as a novel liquid biopsy marker for auxiliary diagnosis and prognosis screening, as well as a possible target for cancer therapy. The molecular mechanism underlying the contribution of DHX32 towards the initiation and development of cancer requires further investigation for the development of anticancer treatments based on manipulating DHX32 expression and function.
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Affiliation(s)
- Qingchun Wei
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, Fujian 361102, P.R. China
| | - Jinting Geng
- Xiamen Key Laboratory of Biomarker Translational Medicine, Center of Medical Laboratory of Xiamen Humanity Hospital, Fujian Medical University, Xiamen, Fujian 361009, P.R. China
| | - Yongquan Chen
- Xiamen Key Laboratory of Biomarker Translational Medicine, Center of Medical Laboratory of Xiamen Humanity Hospital, Fujian Medical University, Xiamen, Fujian 361009, P.R. China
| | - Huayue Lin
- Center of Clinical Laboratory, Xiamen University Affiliated Zhongshan Hospital, Xiamen, Fujian 361104, P.R. China
| | - Jiajia Wang
- Center of Clinical Laboratory, Xiamen University Affiliated Zhongshan Hospital, Xiamen, Fujian 361104, P.R. China
| | - Zanxi Fang
- Center of Clinical Laboratory, Xiamen University Affiliated Zhongshan Hospital, Xiamen, Fujian 361104, P.R. China
| | - Fen Wang
- Center for Cancer and Stem Cell Biology, Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX 77030, USA
| | - Zhongying Zhang
- State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen, Fujian 361102, P.R. China
- Xiamen Key Laboratory of Biomarker Translational Medicine, Center of Medical Laboratory of Xiamen Humanity Hospital, Fujian Medical University, Xiamen, Fujian 361009, P.R. China
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11
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Song B, Liu D, Greco TM, Cristea IM. Post-translational modification control of viral DNA sensors and innate immune signaling. Adv Virus Res 2021; 109:163-199. [PMID: 33934827 PMCID: PMC8489191 DOI: 10.1016/bs.aivir.2021.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The vertebrate innate immune system confers host cells with mechanisms to protect against both evolutionarily ancient pathogens and newly emerging pathogenic strains. Innate immunity relies on the host cell's ability to distinguish between self and pathogen-derived molecules. To achieve this, the innate immune system uses germline encoded receptors called pattern recognition receptors (PRRs), which recognize various molecular signatures, including nucleic acids, proteins, lipids, glycans and glycolipids. Among these molecules, the recognition of pathogenic, mislocalized, or damaged DNA by cellular protein receptors, commonly called DNA sensors, represents a major surveillance pathway for initiating immune signaling. The ability of cells to temporally regulate DNA sensor activation and subsequent signal termination is critical for effective immune signaling. These same mechanisms are also co-opted by pathogens to promote their replication. Therefore, there is significant interest in understanding DNA sensor regulatory networks during microbial infections and autoimmune disease. One emerging aspect of DNA sensor regulation is through post-translational modifications (PTMs), including phosphorylation, acetylation, ubiquitination, ADP-ribosylation, SUMOylation, methylation, deamidation, glutamylation. In this chapter, we discuss how PTMs have been shown to positively or negatively impact DNA sensor functions via diverse mechanisms, including direct regulation of enzymatic activity, protein-protein and protein-DNA interactions, protein translocations and protein turnover. In addition, we highlight the ability of virus-induced PTMs to promote immune evasion. We also discuss the recent evidence linking PTMs on DNA sensors with human diseases and more broadly, highlight promising directions for future research on PTM-mediated regulation of DNA sensor-dependent immune signaling.
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Affiliation(s)
- Bokai Song
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Dawei Liu
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Todd M Greco
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Ileana M Cristea
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States.
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12
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Bussienne C, Marquet R, Paillart JC, Bernacchi S. Post-Translational Modifications of Retroviral HIV-1 Gag Precursors: An Overview of Their Biological Role. Int J Mol Sci 2021; 22:ijms22062871. [PMID: 33799890 PMCID: PMC8000049 DOI: 10.3390/ijms22062871] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/06/2021] [Accepted: 03/09/2021] [Indexed: 11/24/2022] Open
Abstract
Protein post-translational modifications (PTMs) play key roles in eukaryotes since they finely regulate numerous mechanisms used to diversify the protein functions and to modulate their signaling networks. Besides, these chemical modifications also take part in the viral hijacking of the host, and also contribute to the cellular response to viral infections. All domains of the human immunodeficiency virus type 1 (HIV-1) Gag precursor of 55-kDa (Pr55Gag), which is the central actor for viral RNA specific recruitment and genome packaging, are post-translationally modified. In this review, we summarize the current knowledge about HIV-1 Pr55Gag PTMs such as myristoylation, phosphorylation, ubiquitination, sumoylation, methylation, and ISGylation in order to figure out how these modifications affect the precursor functions and viral replication. Indeed, in HIV-1, PTMs regulate the precursor trafficking between cell compartments and its anchoring at the plasma membrane, where viral assembly occurs. Interestingly, PTMs also allow Pr55Gag to hijack the cell machinery to achieve viral budding as they drive recognition between viral proteins or cellular components such as the ESCRT machinery. Finally, we will describe and compare PTMs of several other retroviral Gag proteins to give a global overview of their role in the retroviral life cycle.
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13
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Pan YQ, Xing L. The Current View on the Helicase Activity of RNA Helicase A and Its Role in Gene Expression. Curr Protein Pept Sci 2020; 22:29-40. [PMID: 33143622 DOI: 10.2174/1389203721666201103084122] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/18/2020] [Accepted: 09/09/2020] [Indexed: 11/22/2022]
Abstract
RNA helicase A (RHA) is a DExH-box helicase that plays regulatory roles in a variety of cellular processes, including transcription, translation, RNA splicing, editing, transport, and processing, microRNA genesis and maintenance of genomic stability. It is involved in virus replication, oncogenesis, and innate immune response. RHA can unwind nucleic acid duplex by nucleoside triphosphate hydrolysis. The insight into the molecular mechanism of helicase activity is fundamental to understanding the role of RHA in the cell. Herein, we reviewed the current advances on the helicase activity of RHA and its relevance to gene expression, particularly, to the genesis of circular RNA.
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Affiliation(s)
- Yuan-Qing Pan
- Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi province, China
| | - Li Xing
- Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi province, China
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14
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Guo F, Xing L. RNA helicase A as co-factor for DNA viruses during replication. Virus Res 2020; 291:198206. [PMID: 33132162 DOI: 10.1016/j.virusres.2020.198206] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 10/17/2020] [Accepted: 10/19/2020] [Indexed: 11/30/2022]
Abstract
RNA helicase A (RHA) is a ubiquitously expressed DExH-box helicase enzyme that is involved in a wide range of biological processes including transcription, translation, and RNA processing. A number of RNA viruses recruit RHA to the viral RNA to facilitate virus replication. DNA viruses contain a DNA genome and replicate using a DNA-dependent DNA polymerase. RHA has also been reported to associate with some DNA viruses during replication, in which the enzyme acts on the viral RNA or protein products. As shown for Epstein-Barr virus and Kaposi's sarcoma-associated herpesvirus, RHA has potential to allow the virus to control a switch in cellular gene expression to modulate the antiviral response. While the study of the interaction of RHA with DNA viruses is still at an early stage, preliminary evidence indicates that the underlying molecular mechanisms are diverse. We now review the current status of this emerging field.
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Affiliation(s)
- Fan Guo
- Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi province, PR China
| | - Li Xing
- Institute of Biomedical Sciences, Shanxi University, 92 Wucheng Road, Taiyuan 030006, Shanxi province, PR China.
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15
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PRMT1-dependent methylation of BRCA1 contributes to the epigenetic defense of breast cancer cells against ionizing radiation. Sci Rep 2020; 10:13275. [PMID: 32764667 PMCID: PMC7413540 DOI: 10.1038/s41598-020-70289-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Accepted: 07/27/2020] [Indexed: 12/20/2022] Open
Abstract
The therapeutic effect of irradiation is thought to come from DNA damage that affects rapidly proliferating cancer cells; however, resistant cells rapidly initiate mechanisms to repair such damage. While DNA repair mechanisms responsible for cancer cell survival following DNA damage are understood, less is known about the epigenetic mechanisms resulting in resistance to radiotherapy. Although changes in DNA methylation are related to mechanisms of long-term resistance, it is more likely that the methylation state of a series of proteins could be responsible for the first-line of defense of cancer cells against irradiation. In this study, we observed that irradiation of breast cancer cells was accompanied by an overproduction in S-adenosylmethionine, which increases the activity of cellular methylases. We found that by activating PRMT1, irradiation triggers a BRCA1-dependent program that results in efficient DNA repair and inhibition of apoptosis. Depletion of PRMT1 in irradiated cells resulted in a switch of BRCA1 functions from repair and survival in the nucleus to activation of cell death signals in the cytoplasm. We conclude that by modulating the cellular localization of BRCA1, PRMT1 is an important regulator of the oncogenic functions of BRCA1, contributing to the epigenetic defense of breast cancer cells against ionizing radiation.
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16
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Hartel NG, Chew B, Qin J, Xu J, Graham NA. Deep Protein Methylation Profiling by Combined Chemical and Immunoaffinity Approaches Reveals Novel PRMT1 Targets. Mol Cell Proteomics 2019; 18:2149-2164. [PMID: 31451547 PMCID: PMC6823857 DOI: 10.1074/mcp.ra119.001625] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Indexed: 01/02/2023] Open
Abstract
Protein methylation has been implicated in many important biological contexts including signaling, metabolism, and transcriptional control. Despite the importance of this post-translational modification, the global analysis of protein methylation by mass spectrometry-based proteomics has not been extensively studied because of the lack of robust, well-characterized techniques for methyl peptide enrichment. Here, to better investigate protein methylation, we compared two methods for methyl peptide enrichment: immunoaffinity purification (IAP) and high pH strong cation exchange (SCX). Using both methods, we identified 1720 methylation sites on 778 proteins. Comparison of these methods revealed that they are largely orthogonal, suggesting that the usage of both techniques is required to provide a global view of protein methylation. Using both IAP and SCX, we then investigated changes in protein methylation downstream of protein arginine methyltransferase 1 (PRMT1). PRMT1 knockdown resulted in significant changes to 127 arginine methylation sites on 78 proteins. In contrast, only a single lysine methylation site was significantly changed upon PRMT1 knockdown. In PRMT1 knockdown cells, we found 114 MMA sites that were either significantly downregulated or upregulated on proteins enriched for mRNA metabolic processes. PRMT1 knockdown also induced significant changes in both asymmetric dimethyl arginine (ADMA) and symmetric dimethyl arginine (SDMA). Using characteristic neutral loss fragmentation ions, we annotated dimethylarginines as either ADMA or SDMA. Through integrative analysis of methyl forms, we identified 18 high confidence PRMT1 substrates and 12 methylation sites that are scavenged by other non-PRMT1 arginine methyltransferases in the absence of PRMT1 activity. We also identified one methylation site, HNRNPA1 R206, which switched from ADMA to SDMA upon PRMT1 knockdown. Taken together, our results suggest that deep protein methylation profiling by mass spectrometry requires orthogonal enrichment techniques to identify novel PRMT1 methylation targets and highlight the dynamic interplay between methyltransferases in mammalian cells.
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Affiliation(s)
- Nicolas G Hartel
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089
| | - Brandon Chew
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089
| | - Jian Qin
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90089; Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90089; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California 90089
| | - Jian Xu
- Center for Craniofacial Molecular Biology, University of Southern California, Los Angeles, California 90089; Herman Ostrow School of Dentistry, University of Southern California, Los Angeles, California 90089; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California 90089
| | - Nicholas A Graham
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, California 90089.
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17
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Arginine methylation of FOXP3 is crucial for the suppressive function of regulatory T cells. J Autoimmun 2019; 97:10-21. [DOI: 10.1016/j.jaut.2018.09.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2018] [Revised: 09/26/2018] [Accepted: 09/30/2018] [Indexed: 11/18/2022]
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18
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Meng W, Wang XJ, Wang HCR. Targeting nuclear proteins for control of viral replication. Crit Rev Microbiol 2019; 45:495-513. [DOI: 10.1080/1040841x.2018.1553848] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Wen Meng
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiao-Jia Wang
- Key Laboratory of Animal Epidemiology of the Ministry of Agriculture, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Hwa-Chain Robert Wang
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, The University of Tennessee, Knoxville, USA
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19
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Sumoylated α-synuclein translocates into the nucleus by karyopherin α6. Mol Cell Toxicol 2018. [DOI: 10.1007/s13273-019-0012-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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20
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Lee T, Pelletier J. The biology of DHX9 and its potential as a therapeutic target. Oncotarget 2018; 7:42716-42739. [PMID: 27034008 PMCID: PMC5173168 DOI: 10.18632/oncotarget.8446] [Citation(s) in RCA: 120] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 03/16/2016] [Indexed: 12/25/2022] Open
Abstract
DHX9 is member of the DExD/H-box family of helicases with a “DEIH” sequence at its eponymous DExH-box motif. Initially purified from human and bovine cells and identified as a homologue of the Drosophila Maleless (MLE) protein, it is an NTP-dependent helicase consisting of a conserved helicase core domain, two double-stranded RNA-binding domains at the N-terminus, and a nuclear transport domain and a single-stranded DNA-binding RGG-box at the C-terminus. With an ability to unwind DNA and RNA duplexes, as well as more complex nucleic acid structures, DHX9 appears to play a central role in many cellular processes. Its functions include regulation of DNA replication, transcription, translation, microRNA biogenesis, RNA processing and transport, and maintenance of genomic stability. Because of its central role in gene regulation and RNA metabolism, there are growing implications for DHX9 in human diseases and their treatment. This review will provide an overview of the structure, biochemistry, and biology of DHX9, its role in cancer and other human diseases, and the possibility of targeting DHX9 in chemotherapy.
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Affiliation(s)
- Teresa Lee
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Department of Oncology, McGill University, Montreal, Quebec, Canada.,Department of Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
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21
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Fidaleo M, De Paola E, Paronetto MP. The RNA helicase A in malignant transformation. Oncotarget 2017; 7:28711-23. [PMID: 26885691 PMCID: PMC5053757 DOI: 10.18632/oncotarget.7377] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Accepted: 01/29/2016] [Indexed: 12/12/2022] Open
Abstract
The RNA helicase A (RHA) is involved in several steps of RNA metabolism, such as RNA processing, cellular transit of viral molecules, ribosome assembly, regulation of transcription and translation of specific mRNAs. RHA is a multifunctional protein whose roles depend on the specific interaction with different molecular partners, which have been extensively characterized in physiological situations. More recently, the functional implication of RHA in human cancer has emerged. Interestingly, RHA was shown to cooperate with both tumor suppressors and oncoproteins in different tumours, indicating that its specific role in cancer is strongly influenced by the cellular context. For instance, silencing of RHA and/or disruption of its interaction with the oncoprotein EWS-FLI1 rendered Ewing sarcoma cells more sensitive to genotoxic stresses and affected tumor growth and maintenance, suggesting possible therapeutic implications. Herein, we review the recent advances in the cellular functions of RHA and discuss its implication in oncogenesis, providing a perspective for future studies and potential translational opportunities in human cancer.
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Affiliation(s)
- Marco Fidaleo
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, CERC, Fondazione Santa Lucia, Rome, Italy
| | - Elisa De Paola
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, CERC, Fondazione Santa Lucia, Rome, Italy
| | - Maria Paola Paronetto
- Department of Movement, Human and Health Sciences, University of Rome "Foro Italico", Rome, Italy.,Laboratory of Cellular and Molecular Neurobiology, CERC, Fondazione Santa Lucia, Rome, Italy
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22
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Vangimalla SS, Ganesan M, Kharbanda KK, Osna NA. Bifunctional Enzyme JMJD6 Contributes to Multiple Disease Pathogenesis: New Twist on the Old Story. Biomolecules 2017; 7:biom7020041. [PMID: 28587176 PMCID: PMC5485730 DOI: 10.3390/biom7020041] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Revised: 05/24/2017] [Accepted: 05/26/2017] [Indexed: 02/05/2023] Open
Abstract
Jumonji domain-containing protein 6 (JMJD6) is a non-heme Fe(II) 2-oxoglutarate (2OG)-dependent oxygenase with arginine demethylase and lysyl hydroxylase activities. Its initial discovery as a dispensable phosphatidylserine receptor (PSR) in the cell membrane of macrophages for phagocytosis was squashed by newer studies which revealed its nuclear localization and bifunctional enzymatic activity. Though its interaction with several nuclear and cytoplasmic target proteins has been demonstrated, the exact mechanisms and clinical significance of these various biologic interplays are not yet well established. Recent investigations have shed the light on the multiple pathways by which JMJD6 can regulate cell proliferation and cause tumorigenesis. Clinically, JMJD6 has been associated with more aggressive and metastatic disease, poorer prognosis, and lower overall survival rates-particularly in lung colon and oral cancers. JMJD6 is a novel biomarker for predicting future disease outcomes and is a target for new therapeutic treatments in future studies. Aberrant expression and dysregulation of JMJD6 are implicated in various other processes such as impaired T-cell proliferation and maturation, inoculation, and virulence of foot-and-mouth disease virus (FMDV), and impaired methylation of innate immunity factor. This article reviews the association of JMJD6 with various pathological processes-particularly, its role in tumorigenesis and virological interactions.
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Affiliation(s)
- Shiva Shankar Vangimalla
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, 4101 Woolworth Avenue, Omaha, NE 68105, USA.
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Murali Ganesan
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, 4101 Woolworth Avenue, Omaha, NE 68105, USA.
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, 4101 Woolworth Avenue, Omaha, NE 68105, USA.
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
| | - Natalia A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, 4101 Woolworth Avenue, Omaha, NE 68105, USA.
- Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE 68198, USA.
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23
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Capitanio JS, Montpetit B, Wozniak RW. Human Nup98 regulates the localization and activity of DExH/D-box helicase DHX9. eLife 2017; 6. [PMID: 28221134 PMCID: PMC5338925 DOI: 10.7554/elife.18825] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 02/16/2017] [Indexed: 12/17/2022] Open
Abstract
Beyond their role at nuclear pore complexes, some nucleoporins function in the nucleoplasm. One such nucleoporin, Nup98, binds chromatin and regulates gene expression. To gain insight into how Nup98 contributes to this process, we focused on identifying novel binding partners and understanding the significance of these interactions. Here we report on the identification of the DExH/D-box helicase DHX9 as an intranuclear Nup98 binding partner. Various results, including in vitro assays, show that the FG/GLFG region of Nup98 binds to N- and C-terminal regions of DHX9 in an RNA facilitated manner. Importantly, binding of Nup98 stimulates the ATPase activity of DHX9, and a transcriptional reporter assay suggests Nup98 supports DHX9-stimulated transcription. Consistent with these observations, our analysis revealed that Nup98 and DHX9 bind interdependently to similar gene loci and their transcripts. Based on our results, we propose that Nup98 functions as a co-factor that regulates DHX9 and, potentially, other RNA helicases.
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Affiliation(s)
| | - Ben Montpetit
- Department of Cell Biology, University of Alberta, Edmonton, Canada.,Department of Viticulture and Enology, University of California, Davis, United states
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24
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Charles S, Raj V, Arokiaraj J, Mala K. Caveolin1/protein arginine methyltransferase1/sirtuin1 axis as a potential target against endothelial dysfunction. Pharmacol Res 2017; 119:1-11. [PMID: 28126510 DOI: 10.1016/j.phrs.2017.01.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/20/2016] [Accepted: 01/22/2017] [Indexed: 12/23/2022]
Abstract
Endothelial dysfunction (ED), an established response to cardiovascular risk factors, is characterized by increased levels of soluble molecules secreted by endothelial cells (EC). Evidence suggest that ED is an independent predictor of cardiac events and that it is associated with a deficiency in production or bioavailability of nitric oxide (NO) and/or an imbalance in the relative contribution of endothelium-derived relaxing and contracting factors. ED can be reversed by treating cardiovascular risk factors, hence, beyond ambiguity, ED contributes to initiation and progression of atherosclerotic disease. Majority of cardiovascular risk factors act by a common pathway, oxidative stress (OS), characterized by an imbalance in bioavailability of NO and reactive oxygen species (ROS). Enhanced ROS, through several mechanisms, alters competence of EC that leads to ED, reducing its potential to maintain homeostasis and resulting in development of cardiovascular disease (CVD). Influential mechanisms that have been implicated in the development of ED include (i) presence of elevated levels of NOS inhibitor, asymmetric dimethylarginine (ADMA) due to augmented enzyme activity of protein arginine methyl transferase-1 (PRMT1); (ii) decrease in NO generation by endothelial nitric oxide synthase (eNOS) uncoupling, or by reaction of NO with free radicals and (iii) impaired post translational modification of protein (PTM) such as eNOS, caveolin-1 (cav1) and sirtuin-1 (SIRT1). However, the inter-related mechanisms that concur to developing ED is yet to be understood. The events that possibly overlay include OS-induced sequestration of SIRT1 to caveolae facilitating cav1-SIRT1 association; potential increase in lysine acetylation of enzymes such as eNOS and PRMT1 leading to enhanced ADMA formation; imbalance in acetylation-methylation ratio (AMR); diminished NO generation and ED. Here we review current literature from research showing interdependent association between cav1-PRMT1-SIRT1 to the outcomes of experimental and clinical research aiming to preserve endothelial function with gene- or pharmaco-therapy.
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Affiliation(s)
- Soniya Charles
- Department of Biotechnology, School of Bioengineering, SRM University, Potheri 603203, Tamil Nadu, India
| | - Vijay Raj
- Medical College Hospital and Research Center, SRM University, Potheri 603203, Tamil Nadu, India
| | - Jesu Arokiaraj
- Department of Biotechnology, Faculty of Science and Humanities, SRM University, Potheri 603203, Tamil Nadu, India
| | - Kanchana Mala
- Medical College Hospital and Research Center, SRM University, Potheri 603203, Tamil Nadu, India.
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25
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Abstract
The plasma concentration of asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthase, is the resultant of many processes at cellular and organ levels. Post-translational methylation of arginine residues of pro teins plays a crucial role in the regulation of their functions, which include processes such as transcription, translation and RNA splicing. Because protein methylation is irreversible, the methylation signal can be turned off only by proteolysis of the entire protein. Consequently, most methylated proteins have high turnover rates. Free ADMA, which is formed during proteolysis, is actively degraded by the intracellular enzyme dimethylarginine dimethylaminohydrolase (DDAH). Some ADMA escapes degradation and leaves the cell via cationic amino acid transporters. These trans porters also mediate uptake of ADMA by neighboring cells or distant organs, thereby facilitating active interorgan transport. Clearance of ADMA from the plasma occurs in small part by urinary excretion, but the bulk of ADMA is degraded by intracellular DDAH, after uptake from the circulation. This review discusses the various processes involved in ADMA metabolism: protein methylation, proteolysis of methylated proteins, metabolism by DDAH, and interorgan transport. In addition, the role of the kidney and the liver in the clearance of ADMA is highlighted.
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Affiliation(s)
- Tom Teerlink
- 1Department of Clinical Chemistry, VU University Medical
Center, Amsterdam, The Netherland
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26
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Gao X, Jin Q, Jiang C, Li Y, Li C, Liu H, Kang Z, Xu JR. FgPrp4 Kinase Is Important for Spliceosome B-Complex Activation and Splicing Efficiency in Fusarium graminearum. PLoS Genet 2016; 12:e1005973. [PMID: 27058959 PMCID: PMC4825928 DOI: 10.1371/journal.pgen.1005973] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 03/11/2016] [Indexed: 12/23/2022] Open
Abstract
PRP4 encodes the only kinase among the spliceosome components. Although it is an essential gene in the fission yeast and other eukaryotic organisms, the Fgprp4 mutant was viable in the wheat scab fungus Fusarium graminearum. Deletion of FgPRP4 did not block intron splicing but affected intron splicing efficiency in over 60% of the F. graminearum genes. The Fgprp4 mutant had severe growth defects and produced spontaneous suppressors that were recovered in growth rate. Suppressor mutations were identified in the PRP6, PRP31, BRR2, and PRP8 orthologs in nine suppressor strains by sequencing analysis with candidate tri-snRNP component genes. The Q86K mutation in FgMSL1 was identified by whole genome sequencing in suppressor mutant S3. Whereas two of the suppressor mutations in FgBrr2 and FgPrp8 were similar to those characterized in their orthologs in yeasts, suppressor mutations in Prp6 and Prp31 orthologs or FgMSL1 have not been reported. Interestingly, four and two suppressor mutations identified in FgPrp6 and FgPrp31, respectively, all are near the conserved Prp4-phosphorylation sites, suggesting that these mutations may have similar effects with phosphorylation by Prp4 kinase. In FgPrp31, the non-sense mutation at R464 resulted in the truncation of the C-terminal 130 aa region that contains all the conserved Prp4-phosphorylation sites. Deletion analysis showed that the N-terminal 310-aa rich in SR residues plays a critical role in the localization and functions of FgPrp4. We also conducted phosphoproteomics analysis with FgPrp4 and identified S289 as the phosphorylation site that is essential for its functions. These results indicated that FgPrp4 is critical for splicing efficiency but not essential for intron splicing, and FgPrp4 may regulate pre-mRNA splicing by phosphorylation of other components of the tri-snRNP although itself may be activated by phosphorylation at S289.
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Affiliation(s)
- Xuli Gao
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Qiaojun Jin
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Cong Jiang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Yang Li
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
| | - Chaohui Li
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Huiquan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhensheng Kang
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
| | - Jin-Rong Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China
- Dept. of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana, United States of America
- * E-mail:
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Low JKK, Im H, Erce MA, Hart-Smith G, Snyder MP, Wilkins MR. Protein substrates of the arginine methyltransferase Hmt1 identified by proteome arrays. Proteomics 2016; 16:465-76. [DOI: 10.1002/pmic.201400564] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Revised: 09/27/2015] [Accepted: 11/10/2015] [Indexed: 01/22/2023]
Affiliation(s)
- Jason K. K. Low
- Systems Biology Initiative; School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
| | - Hogune Im
- Department of Genetics; Stanford University School of Medicine; Palo Alto CA USA
| | - Melissa A. Erce
- Systems Biology Initiative; School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
| | - Gene Hart-Smith
- Systems Biology Initiative; School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
| | - Michael P. Snyder
- Department of Genetics; Stanford University School of Medicine; Palo Alto CA USA
| | - Marc R. Wilkins
- Systems Biology Initiative; School of Biotechnology and Biomolecular Sciences; The University of New South Wales; Sydney Australia
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Sylvestersen KB, Nielsen ML. Large‐Scale Identification of the Arginine Methylome by Mass Spectrometry. ACTA ACUST UNITED AC 2015; 82:24.7.1-24.7.17. [DOI: 10.1002/0471140864.ps2407s82] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Kathrine B. Sylvestersen
- Department of Proteomics The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences Copenhagen Denmark
| | - Michael L. Nielsen
- Department of Proteomics The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Faculty of Health Sciences Copenhagen Denmark
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29
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Christie M, Chang CW, Róna G, Smith KM, Stewart AG, Takeda AAS, Fontes MRM, Stewart M, Vértessy BG, Forwood JK, Kobe B. Structural Biology and Regulation of Protein Import into the Nucleus. J Mol Biol 2015; 428:2060-90. [PMID: 26523678 DOI: 10.1016/j.jmb.2015.10.023] [Citation(s) in RCA: 188] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/16/2015] [Accepted: 10/24/2015] [Indexed: 11/28/2022]
Abstract
Proteins are translated in the cytoplasm, but many need to access the nucleus to perform their functions. Understanding how these nuclear proteins are transported through the nuclear envelope and how the import processes are regulated is therefore an important aspect of understanding cell function. Structural biology has played a key role in understanding the molecular events during the transport processes and their regulation, including the recognition of nuclear targeting signals by the corresponding receptors. Here, we review the structural basis of the principal nuclear import pathways and the molecular basis of their regulation. The pathways involve transport factors that are members of the β-karyopherin family, which can bind cargo directly (e.g., importin-β, transportin-1, transportin-3, importin-13) or through adaptor proteins (e.g., importin-α, snurportin-1, symportin-1), as well as unrelated transport factors such as Hikeshi, involved in the transport of heat-shock proteins, and NTF2, involved in the transport of RanGDP. Solenoid proteins feature prominently in these pathways. Nuclear transport factors recognize nuclear targeting signals on the cargo proteins, including the classical nuclear localization signals, recognized by the adaptor importin-α, and the PY nuclear localization signals, recognized by transportin-1. Post-translational modifications, particularly phosphorylation, constitute key regulatory mechanisms operating in these pathways.
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Affiliation(s)
- Mary Christie
- The Garvan Institute of Medical Research, 384 Victoria Street, Darlinghurst, NSW 2010, Australia; St Vincent's Clinical School, University of New South Wales Faculty of Medicine, Darlinghurst, NSW 2010, Australia
| | - Chiung-Wen Chang
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia; Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Gergely Róna
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest H-1117, Hungary; Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Kate M Smith
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
| | - Alastair G Stewart
- School of Molecular Bioscience, The University of Sydney, Sydney, NSW 2006, Australia
| | - Agnes A S Takeda
- Department of Physics and Biophysics, Institute of Biosciences, Universidade Estadual Paulista, Botucatu, São Paulo 18618-000, Brazil
| | - Marcos R M Fontes
- Department of Physics and Biophysics, Institute of Biosciences, Universidade Estadual Paulista, Botucatu, São Paulo 18618-000, Brazil
| | - Murray Stewart
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia; MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge CB2 0QH, United Kingdom
| | - Beáta G Vértessy
- Institute of Enzymology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest H-1117, Hungary; Department of Applied Biotechnology and Food Sciences, Budapest University of Technology and Economics, Budapest H-1111, Hungary
| | - Jade K Forwood
- School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW 2650, Australia
| | - Bostjan Kobe
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia.
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Baldwin RM, Bejide M, Trinkle-Mulcahy L, Côté J. Identification of the PRMT1v1 and PRMT1v2 specific interactomes by quantitative mass spectrometry in breast cancer cells. Proteomics 2015; 15:2187-97. [DOI: 10.1002/pmic.201400209] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 01/29/2015] [Accepted: 02/12/2015] [Indexed: 11/10/2022]
Affiliation(s)
- R. Mitchell Baldwin
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa ON Canada
- Faculty of Medicine; University of Ottawa; Ottawa ON Canada
| | - Margaret Bejide
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa ON Canada
- Faculty of Medicine; University of Ottawa; Ottawa ON Canada
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa ON Canada
- Faculty of Medicine; University of Ottawa; Ottawa ON Canada
| | - Jocelyn Côté
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa ON Canada
- Faculty of Medicine; University of Ottawa; Ottawa ON Canada
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31
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Kaehler C, Guenther A, Uhlich A, Krobitsch S. PRMT1-mediated arginine methylation controls ATXN2L localization. Exp Cell Res 2015; 334:114-25. [PMID: 25748791 DOI: 10.1016/j.yexcr.2015.02.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 02/20/2015] [Accepted: 02/25/2015] [Indexed: 01/02/2023]
Abstract
Arginine methylation is a posttranslational modification that is of importance in diverse cellular processes. Recent proteomic mass spectrometry studies reported arginine methylation of ataxin-2-like (ATXN2L), the paralog of ataxin-2, a protein that is implicated in the neurodegenerative disorder spinocerebellar ataxia type 2. Here, we investigated the methylation state of ATXN2L and its significance for ATXN2L localization. We first confirmed that ATXN2L is asymmetrically dimethylated in vivo, and observed that the nuclear localization of ATXN2L is altered under methylation inhibition. We further discovered that ATXN2L associates with the protein arginine-N-methyltransferase 1 (PRMT1). Finally, we showed that neither mutation of the arginine-glycine-rich motifs of ATXN2L nor methylation inhibition alters ATXN2L localization to stress granules, suggesting that methylation of ATXN2L is probably not mandatory.
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Affiliation(s)
- Christian Kaehler
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anika Guenther
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Anja Uhlich
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany
| | - Sylvia Krobitsch
- Max Planck Institute for Molecular Genetics, Ihnestrasse 63-73, 14195 Berlin, Germany.
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32
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Mann M, Zou Y, Chen Y, Brann D, Vadlamudi R. PELP1 oncogenic functions involve alternative splicing via PRMT6. Mol Oncol 2014; 8:389-400. [PMID: 24447537 PMCID: PMC3943689 DOI: 10.1016/j.molonc.2013.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2013] [Revised: 12/06/2013] [Accepted: 12/18/2013] [Indexed: 10/25/2022] Open
Abstract
Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1) is a proto-oncogene that functions as coactivator of the estrogen receptor and is an independent prognostic predictor of shorter survival of breast cancer patients. The dysregulation of PELP1 in breast cancer has been implicated in oncogenesis, metastasis, and therapy resistance. Although several aspects of PELP1 have been studied, a complete list of PELP1 target genes remains unknown, and the molecular mechanisms of PELP1 mediated oncogenesis remain elusive. In this study, we have performed a whole genome analysis to profile the PELP1 transcriptome by RNA-sequencing and identified 318 genes as PELP1 regulated genes. Pathway analysis revealed that PELP1 modulates several pathways including the molecular mechanisms of cancer, estrogen signaling, and breast cancer progression. Interestingly, RNA-seq analysis also revealed that PELP1 regulates the expression of several genes involved in alternative splicing. Accordingly, the PELP1 regulated genome includes several uniquely spliced isoforms. Mechanistic studies show that PELP1 binds RNA with a preference to poly-C, co-localizes with the splicing factor SC35 at nuclear speckles, and participates in alternative splicing. Further, PELP1 interacts with the arginine methyltransferase PRMT6 and modifies PRMT6 functions. Inhibition of PRMT6 reduced PELP1-mediated estrogen receptor activation, cellular proliferation, and colony formation. PELP1 and PRMT6 are co-recruited to estrogen receptor target genes, PELP1 knockdown affects the enrichment of histone H3R2 di-methylation, and PELP1 and PRMT6 coordinate to regulate the alternative splicing of genes involved in cancer. Collectively, our data suggest that PELP1 oncogenic functions involve alternative splicing leading to the activation of unique pathways that support tumor progression and that the PELP1-PRMT6 axis may be a potential target for breast cancer therapy.
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Affiliation(s)
- Monica Mann
- The Department of Cellular and Structural Biology, San Antonio, TX 78229, USA; The Department of Obstetrics and Gynecology, San Antonio, TX 78229, USA.
| | - Yi Zou
- Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
| | - Yidong Chen
- Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
| | - Darrell Brann
- Institute of Molecular Medicine and Genetics, Georgia Regents University, Augusta, GA 30912, USA.
| | - Ratna Vadlamudi
- The Department of Obstetrics and Gynecology, San Antonio, TX 78229, USA; Cancer Therapy and Research Center, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
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Chen ZX, Wallis K, Fell SM, Sobrado VR, Hemmer MC, Ramsköld D, Hellman U, Sandberg R, Kenchappa RS, Martinson T, Johnsen JI, Kogner P, Schlisio S. RNA helicase A is a downstream mediator of KIF1Bβ tumor-suppressor function in neuroblastoma. Cancer Discov 2014; 4:434-51. [PMID: 24469107 DOI: 10.1158/2159-8290.cd-13-0362] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
UNLABELLED Inherited KIF1B loss-of-function mutations in neuroblastomas and pheochromocytomas implicate the kinesin KIF1B as a 1p36.2 tumor suppressor. However, the mechanism of tumor suppression is unknown. We found that KIF1B isoform β (KIF1Bβ) interacts with RNA helicase A (DHX9), causing nuclear accumulation of DHX9, followed by subsequent induction of the proapoptotic XIAP-associated factor 1 (XAF1) and, consequently, apoptosis. Pheochromocytoma and neuroblastoma arise from neural crest progenitors that compete for growth factors such as nerve growth factor (NGF) during development. KIF1Bβ is required for developmental apoptosis induced by competition for NGF. We show that DHX9 is induced by and required for apoptosis stimulated by NGF deprivation. Moreover, neuroblastomas with chromosomal deletion of 1p36 exhibit loss of KIF1Bβ expression and impaired DHX9 nuclear localization, implicating the loss of DHX9 nuclear activity in neuroblastoma pathogenesis. SIGNIFICANCE KIF1Bβ has neuroblastoma tumor-suppressor properties and promotes and requires nuclear-localized DHX9 for its apoptotic function by activating XAF1 expression. Loss of KIF1Bβ alters subcellular localization of DHX9 and diminishes NGF dependence of sympathetic neurons, leading to reduced culling of neural progenitors, and, therefore, might predispose to tumor formation.
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Affiliation(s)
- Zhi Xiong Chen
- 1Ludwig Institute for Cancer Research Ltd.; 2Department of Cell and Molecular Biology, Karolinska Institutet; 3Department of Women's and Children's Health, Karolinska University Hospital, Stockholm; 4Ludwig Institute for Cancer Research Ltd., Biomedical Center, Uppsala; 5Department of Clinical Genetics, Institute of Biomedicine, University of Gothenburg, Sahlgrenska University Hospital, Göteborg, Sweden; and 6Moffitt Cancer Center, Neuro-Oncology Program, Tampa, Florida
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Lawrence P, Conderino JS, Rieder E. Redistribution of demethylated RNA helicase A during foot-and-mouth disease virus infection: role of Jumonji C-domain containing protein 6 in RHA demethylation. Virology 2014; 452-453:1-11. [PMID: 24606677 DOI: 10.1016/j.virol.2013.12.040] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 12/20/2013] [Accepted: 12/28/2013] [Indexed: 11/20/2022]
Abstract
Previously, RNA helicase A (RHA) re-localization from the nucleus to the cytoplasm in foot-and-mouth disease virus (FMDV) infected cells was shown to coincide with loss of RHA methylated arginine residues at its C-terminus. The potential interaction between RHA and Jumonji C-domain (JmjC) protein 6 (JMJD6) arginine demethylase in infected cells was investigated. Treatment with N-oxalylglycine (NOG) inhibitor of JmjC demethylases prevented FMDV-induced RHA demethylation and re-localization, and also decreased viral protein synthesis and virus titers. Physical interaction between JMJD6 and RHA was demonstrated via reciprocal co-immunoprecipitation, where RHA preferentially bound JMJD6 monomers. Nuclear efflux of demethylated RHA (DM-RHA) coincided with nuclear influx of JMJD6, which was not observed using another picornavirus. A modified biochemical assay demonstrated JMJD6 induced dose-dependent demethylation of RHA and two RHA-derived isoforms, which could be inhibited by NOG. We propose a role for JMJD6 in RHA demethylation stimulated by FMDV, that appears to facilitate virus replication.
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Affiliation(s)
- Paul Lawrence
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, NAA, Plum Island Animal Disease Center, PO Box 848, Greenport, NY 11944-0848, USA
| | - Joseph S Conderino
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, NAA, Plum Island Animal Disease Center, PO Box 848, Greenport, NY 11944-0848, USA
| | - Elizabeth Rieder
- Foreign Animal Disease Research Unit, United States Department of Agriculture, Agricultural Research Service, NAA, Plum Island Animal Disease Center, PO Box 848, Greenport, NY 11944-0848, USA.
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35
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Low JK, Hart-Smith G, Erce MA, Wilkins MR. Analysis of the Proteome of Saccharomyces cerevisiae for Methylarginine. J Proteome Res 2013; 12:3884-99. [DOI: 10.1021/pr400556c] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jason K.K. Low
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Gene Hart-Smith
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Melissa A. Erce
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
| | - Marc R. Wilkins
- Systems Biology Laboratory, School of Biotechnology
and Biomolecular Sciences, The University of New South Wales, NSW 2052 Sydney, Australia
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36
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Identification of a novel lipin homologue from the parasitic protozoan Trypanosoma brucei. BMC Microbiol 2013; 13:101. [PMID: 23656927 PMCID: PMC3654991 DOI: 10.1186/1471-2180-13-101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2012] [Accepted: 05/06/2013] [Indexed: 02/03/2023] Open
Abstract
Background Arginine methylation is a post-translational modification that expands the functional diversity of proteins. Kinetoplastid parasites contain a relatively large group of protein arginine methyltransferases (PRMTs) compared to other single celled eukaryotes. Several T. brucei proteins have been shown to serve as TbPRMT substrates in vitro, and a great number of proteins likely to undergo methylation are predicted by the T. brucei genome. This indicates that a large number of proteins whose functions are modulated by arginine methylation await discovery in trypanosomes. Here, we employed a yeast two-hybrid screen using as bait the major T. brucei type I PRMT, TbPRMT1, to identify potential substrates of this enzyme. Results We identified a protein containing N-LIP and C-LIP domains that we term TbLpn. These domains are usually present in a family of proteins known as lipins, and involved in phospholipid biosynthesis and gene regulation. Far western and co-immunoprecipitation assays confirmed the TbPRMT1-TbLpn interaction. We also demonstrated that TbLpn is localized mainly to the cytosol, and is methylated in vivo. In addition, we showed that, similar to mammalian and yeast proteins with N-LIP and C-LIP domains, recombinant TbLpn exhibits phosphatidic acid phosphatase activity, and that two conserved aspartic acid residues present in the C-LIP domain are critical for its enzymatic activity. Conclusions This study reports the characterization of a novel trypanosome protein and provides insight into its enzymatic activity and function in phospholipid biosynthesis. It also indicates that TbLpn functions may be modulated by arginine methylation.
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Secondary metabolism and development is mediated by LlmF control of VeA subcellular localization in Aspergillus nidulans. PLoS Genet 2013; 9:e1003193. [PMID: 23341778 PMCID: PMC3547832 DOI: 10.1371/journal.pgen.1003193] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Accepted: 11/09/2012] [Indexed: 12/22/2022] Open
Abstract
Secondary metabolism and development are linked in Aspergillus through the conserved regulatory velvet complex composed of VeA, VelB, and LaeA. The founding member of the velvet complex, VeA, shuttles between the cytoplasm and nucleus in response to alterations in light. Here we describe a new interaction partner of VeA identified through a reverse genetics screen looking for LaeA-like methyltransferases in Aspergillus nidulans. One of the putative LaeA-like methyltransferases identified, LlmF, is a negative regulator of sterigmatocystin production and sexual development. LlmF interacts directly with VeA and the repressive function of LlmF is mediated by influencing the localization of VeA, as over-expression of llmF decreases the nuclear to cytoplasmic ratio of VeA while deletion of llmF results in an increased nuclear accumulation of VeA. We show that the methyltransferase domain of LlmF is required for function; however, LlmF does not directly methylate VeA in vitro. This study identifies a new interaction partner for VeA and highlights the importance of cellular compartmentalization of VeA for regulation of development and secondary metabolism. In recent years there has been increased interest in bioactive small molecules produced by filamentous fungi. Members of the genus Aspergillus are prolific producers of natural products such as penicillin, the cholesterol lowering drug lovastatin, in addition to several toxins, the most famous being aflatoxin. The genetic regulation of fungal natural products is coupled with developmental differentiation through a conserved protein complex termed the velvet complex. The founding member of the complex, velvet (VeA), is a light-regulated protein that shuttles between the cytoplasm and nucleus in response to illumination. Once in the nucleus, VeA interacts with the putative methyltransferase LaeA to positively regulate production of secondary metabolites and with VelB to induce sexual development. We have identified a new interaction partner of VeA that has sequence homology to LaeA. The putative LaeA-like methyltransferase LlmF controls the subcellular localization of VeA in response to light, thereby regulating the downstream outputs of secondary metabolism and development. While the mechanism of the velvet complex remains an enigma, our data suggest that manipulation of protein subcellular localization is an approach that can be used to control production of secondary metabolites.
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38
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Low JKK, Wilkins MR. Protein arginine methylation in Saccharomyces cerevisiae. FEBS J 2012; 279:4423-43. [PMID: 23094907 DOI: 10.1111/febs.12039] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Revised: 10/10/2012] [Accepted: 10/19/2012] [Indexed: 11/27/2022]
Abstract
Recent research has implicated arginine methylation as a major regulator of cellular processes, including transcription, translation, nucleocytoplasmic transport, signalling, DNA repair, RNA processing and splicing. Arginine methylation is evolutionarily conserved, and it is now thought that it may rival other post-translational modifications such as phosphorylation in terms of its occurrence in the proteome. In addition, multiple recent examples demonstrate an exciting new theme: the interplay between methylation and other post-translational modifications such as phosphorylation. In this review, we summarize our current understanding of arginine methylation and the recent advances made, with a focus on the lower eukaryote Saccharomyces cerevisiae. We cover the types of methylated proteins, their responsible methyltransferases, where and how the effects of arginine methylation are seen in the cell, and, finally, discuss the conservation of the biological function of methylarginines between S. cerevisiae and mammals.
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Affiliation(s)
- Jason K K Low
- Systems Biology Laboratory, School of Biotechnology and Biomolecular Sciences, The University of New South Wales, Sydney, Australia
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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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40
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Ahmad A, Cao X. Plant PRMTs broaden the scope of arginine methylation. J Genet Genomics 2012; 39:195-208. [PMID: 22624881 DOI: 10.1016/j.jgg.2012.04.001] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/02/2012] [Accepted: 04/02/2012] [Indexed: 01/22/2023]
Abstract
Post-translational methylation at arginine residues is one of the most important covalent modifications of proteins, involved in a myriad of essential cellular processes in eukaryotes, such as transcriptional regulation, RNA processing, signal transduction, and DNA repair. Methylation at arginine residues is catalyzed by a family of enzymes called protein arginine methyltransferases (PRMTs). PRMTs have been extensively studied in various taxa and there is a growing tendency to unveil their functional importance in plants. Recent studies in plants revealed that this evolutionarily conserved family of enzymes regulates essential traits including vegetative growth, flowering time, circadian cycle, and response to high medium salinity and ABA. In this review, we highlight recent advances in the field of post-translational arginine methylation with special emphasis on the roles and future prospects of this modification in plants.
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Affiliation(s)
- Ayaz Ahmad
- State Key Laboratory of Plant Genomics and National Center for Plant Gene Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Datun Road #5, Beijing 100101, China
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41
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Caplin B, Leiper J. Endogenous nitric oxide synthase inhibitors in the biology of disease: markers, mediators, and regulators? Arterioscler Thromb Vasc Biol 2012; 32:1343-53. [PMID: 22460557 DOI: 10.1161/atvbaha.112.247726] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The asymmetric methylarginines inhibit nitric oxide synthesis in vivo by competing with L-arginine at the active site of nitric oxide synthase. High circulating levels of asymmetric dimethylarginine predict adverse outcomes, specifically vascular events but there is now increasing experimental and epidemiological evidence that these molecules, and the enzymes that regulate this pathway, play a mechanistic role in cardiovascular diseases. Recent data have provided insight into the impact of altered levels of these amino acids in both humans and rodents, however these reports also suggest a simplistic approach based on measuring, and modulating circulating asymmetric dimethylarginine alone is inadequate. This review outlines the basic biochemistry and physiology of endogenous methylarginines, examines both the experimental and observational evidence for a role in disease pathogenesis, and examines the potential for therapeutic regulation of these molecules.
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Affiliation(s)
- Ben Caplin
- Centre for Nephrology, UCL Medical School, Royal Free Campus 2nd Floor, Rowland Hill St, London NW3 2PF.
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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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Abstract
Protozoa constitute the earliest branch of the eukaryotic lineage, and several groups of protozoans are serious parasites of humans and other animals. Better understanding of biochemical pathways that are either in common with or divergent from those of higher eukaryotes is integral in the defense against these parasites. In yeast and humans, the posttranslational methylation of arginine residues in proteins affects myriad cellular processes, including transcription, RNA processing, DNA replication and repair, and signal transduction. The protein arginine methyltransferases (PRMTs) that catalyze these reactions, which are unique to the eukaryotic kingdom of organisms, first become evident in protozoa. In this review, we focus on the current understanding of arginine methylation in multiple species of parasitic protozoa, including Trichomonas, Entamoeba, Toxoplasma, Plasmodium, and Trypanosoma spp., and discuss how arginine methylation may play important and unique roles in each type of parasite. We mine available genomic and transcriptomic data to inventory the families of PRMTs in different parasites and the changes in their abundance during the life cycle. We further review the limited functional studies on the roles of arginine methylation in parasites, including epigenetic regulation in Apicomplexa and RNA processing in trypanosomes. Interestingly, each of the parasites considered herein has significantly differing sets of PRMTs, and we speculate on the importance of this diversity in aspects of parasite biology, such as differentiation and antigenic variation.
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44
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Arginine methylation of the RGG box does not appear to regulate ICP27 import during herpes simplex virus infection. J Virol 2011; 85:6809-13. [PMID: 21543499 DOI: 10.1128/jvi.00679-11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Arginine methylation can regulate protein import and export and can modulate protein interactions. Herpes simplex virus 1 (HSV-1) ICP27 is a shuttling protein involved in viral mRNA export. We previously reported that ICP27 is methylated on three arginines within its RGG box and that arginine methylation regulates ICP27 export and its interaction with SRPK1 and Aly/REF. Here, we report that ICP27 was efficiently imported into the nucleus when hypomethylated as determined by Fluorescence Recovery After Photobleaching (FRAP). Furthermore, coimmunoprecipitation of ICP27 with β-importin was not significantly affected by ICP27 hypomethylation. Thus, ICP27 import does not appear to be regulated by arginine methylation.
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The multifaceted poliovirus 2A protease: regulation of gene expression by picornavirus proteases. J Biomed Biotechnol 2011; 2011:369648. [PMID: 21541224 PMCID: PMC3085340 DOI: 10.1155/2011/369648] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 01/18/2011] [Accepted: 02/17/2011] [Indexed: 11/17/2022] Open
Abstract
After entry into animal cells, most viruses hijack essential components involved in gene expression. This is the case of poliovirus, which abrogates cellular translation soon after virus internalization. Abrogation is achieved by cleavage of both eIF4GI and eIF4GII by the viral protease 2A. Apart from the interference of poliovirus with cellular protein synthesis, other gene expression steps such as RNA and protein trafficking between nucleus and cytoplasm are also altered. Poliovirus 2Apro is capable of hydrolyzing components of the nuclear pore, thus preventing an efficient antiviral response by the host cell. Here, we compare in detail poliovirus 2Apro with other viral proteins (from picornaviruses and unrelated families) as regard to their activity on key host factors that control gene expression. It is possible that future analyses to determine the cellular proteins targeted by 2Apro will uncover other cellular functions ablated by poliovirus infection. Further understanding of the cellular proteins hydrolyzed by 2Apro will add further insight into the molecular mechanism by which poliovirus and other viruses interact with the host cell.
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Yu MC. The Role of Protein Arginine Methylation in mRNP Dynamics. Mol Biol Int 2011; 2011:163827. [PMID: 22091396 PMCID: PMC3195771 DOI: 10.4061/2011/163827] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Accepted: 02/12/2011] [Indexed: 12/13/2022] Open
Abstract
In eukaryotes, messenger RNA biogenesis depends on the ordered and precise assembly of a nuclear messenger ribonucleoprotein particle (mRNP) during transcription. This process requires a well-orchestrated and dynamic sequence of molecular recognition events by specific RNA-binding proteins. Arginine methylation is a posttranslational modification found in a plethora of RNA-binding proteins responsible for mRNP biogenesis. These RNA-binding proteins include both heterogeneous nuclear ribonucleoproteins (hnRNPs) and serine/arginine-rich (SR) proteins. In this paper, I discuss the mechanisms of action by which arginine methylation modulates various facets of mRNP biogenesis, and how the collective consequences of this modification impart the specificity required to generate a mature, translational- and export-competent mRNP.
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Affiliation(s)
- Michael C Yu
- Department of Biological Sciences, State University of New York at Buffalo, 109 Cooke Hall, Buffalo, NY 14260, USA
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Ranji A, Shkriabai N, Kvaratskhelia M, Musier-Forsyth K, Boris-Lawrie K. Features of double-stranded RNA-binding domains of RNA helicase A are necessary for selective recognition and translation of complex mRNAs. J Biol Chem 2010; 286:5328-37. [PMID: 21123178 DOI: 10.1074/jbc.m110.176339] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The DExH protein RNA helicase A (RHA) plays numerous roles in cell physiology, and post-transcriptional activation of gene expression is a major role among them. RHA selectively activates translation of complex cellular and retroviral mRNAs. Although RHA requires interaction with structural features of the 5'-UTR of these target mRNAs, the molecular basis of their translation activation by RHA is poorly understood. RHA contains a conserved ATPase-dependent helicase core that is flanked by two α-β-β-β-α double-stranded RNA-binding domains at the N terminus and repeated arginine-glycine residues at the C terminus. The individual recombinant N-terminal, central helicase, and C-terminal domains were evaluated for their ability to specifically interact with cognate RNAs by in vitro biochemical measurements and mRNA translation assays in cells. The results demonstrate that N-terminal residues confer selective interaction with retroviral and junD target RNAs. Conserved lysine residues in the distal α-helix of the double-stranded RNA-binding domains are necessary to engage structural features of retroviral and junD 5'-UTRs. Exogenous expression of the N terminus coprecipitates junD mRNA and inhibits the translation activity of endogenous RHA. The results indicate that the molecular basis for the activation of translation by RHA is recognition of target mRNA by the N-terminal domain that tethers the ATP-dependent helicase for rearrangement of the complex 5'-UTR.
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Affiliation(s)
- Arnaz Ranji
- Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210, USA
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Coordinate roles of Gag and RNA helicase A in promoting the annealing of formula to HIV-1 RNA. J Virol 2010; 85:1847-60. [PMID: 21106734 DOI: 10.1128/jvi.02010-10] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
RNA helicase A (RHA) has been shown to promote HIV-1 replication at both the translation and reverse transcription stages. A prerequisite step for reverse transcription involves the annealing of tRNA(3)(Lys), the primer for reverse transcription, to HIV-1 RNA. tRNA(3)(Lys) annealing is a multistep process that is initially facilitated by Gag prior to viral protein processing. Herein, we report that RHA promotes this annealing through increasing both the quantity of tRNA(3)(Lys) annealed by Gag and the ability of tRNA(3)(Lys) to prime the initiation of reverse transcription. This improved annealing is the result of an altered viral RNA conformation produced by the coordinate action of Gag and RHA. Since RHA has been reported to promote the translation of unspliced viral RNA to Gag protein, our observations suggest that the conformational change in viral RNA induced by RHA and newly produced Gag may help facilitate the switch in viral RNA from a translational mode to one facilitating tRNA(3)(Lys) annealing.
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Ranji A, Boris-Lawrie K. RNA helicases: emerging roles in viral replication and the host innate response. RNA Biol 2010; 7:775-87. [PMID: 21173576 DOI: 10.4161/rna.7.6.14249] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
RNA helicases serve multiple roles at the virus-host interface. In some situations, RNA helicases are essential host factors to promote viral replication; however, in other cases they serve as a cellular sensor to trigger the antiviral state in response to viral infection. All family members share the conserved ATP-dependent catalytic core linked to different substrate recognition and protein-protein interaction domains. These flanking domains can be shuffled between different helicases to achieve functional diversity. This review summarizes recent studies, which have revealed two types of activity by RNA helicases. First, RNA helicases are catalysts of progressive RNA-protein rearrangements that begin at gene transcription and culminate in mRNA translation. Second, RNA helicases can act as a scaffold for alternative protein-protein interactions that can defeat the antiviral state. The mounting fundamental understanding of RNA helicases is being used to develop selective and efficacious drugs against human and animal pathogens. The analysis of RNA helicases in virus model systems continues to provide insights into virology, cell biology and immunology, and has provided fresh perspective to continue unraveling the complexity of virus-host interactions.
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Affiliation(s)
- Arnaz Ranji
- Department of Veterinary Biosciences, Ohio State University, Columbus, OH, USA
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50
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Kaposi's sarcoma-associated herpesvirus viral protein kinase interacts with RNA helicase a and regulates host gene expression. J Microbiol 2010; 48:206-12. [PMID: 20437153 DOI: 10.1007/s12275-010-0021-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Accepted: 02/22/2010] [Indexed: 10/19/2022]
Abstract
RNA helicase A (RHA) containing the DExH motif is a human homolog of maleless protein that regulates expression of genes located in the Drosophila X chromosome during dosage compensation. RHA exerts helicase activity that unwinds double-stranded RNA and DNA to a single-strand form. The protein acts as a bridging factor mediating interactions of CBP/p300 and RNA pol II, and consequently affects gene expression. Kaposi's sarcoma-associated herpesvirus (KSHV) is a member of the gamma-herpesvirus subfamily that causes several disorders. The majority of herpesviruses commonly encode predicted viral protein kinases. KSHV open reading frame 36 (ORF36) codes for protein kinase domains, and functions as a serine/threonine protein kinase. KSHV ORF36 is classified as a late gene, as it is expressed during lytic replication and localized in the nuclei of KSHV-infected cells. Recent studies show that viral protein kinase (vPK) interacts with cellular proteins. In this study, we determined the cellular localization of vPK in KSHV-infected BCBL-1 cells using confocal microscopy. Proteomic analysis indicates that cellular proteins interacted with vPK, and co-immunoprecipitation reactions further reveal interactions between vPK and RHA. Moreover, KSHV vPK appeared to regulate the transcriptional activation of Cre promoter, and plays an important role in cellular transcription of RHA.
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