1
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Brito Querido J, Sokabe M, Díaz-López I, Gordiyenko Y, Zuber P, Du Y, Albacete-Albacete L, Ramakrishnan V, Fraser CS. Human tumor suppressor protein Pdcd4 binds at the mRNA entry channel in the 40S small ribosomal subunit. Nat Commun 2024; 15:6633. [PMID: 39117603 PMCID: PMC11310195 DOI: 10.1038/s41467-024-50672-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 07/17/2024] [Indexed: 08/10/2024] Open
Abstract
Translation is regulated mainly in the initiation step, and its dysregulation is implicated in many human diseases. Several proteins have been found to regulate translational initiation, including Pdcd4 (programmed cell death gene 4). Pdcd4 is a tumor suppressor protein that prevents cell growth, invasion, and metastasis. It is downregulated in most tumor cells, while global translation in the cell is upregulated. To understand the mechanisms underlying translational control by Pdcd4, we used single-particle cryo-electron microscopy to determine the structure of human Pdcd4 bound to 40S small ribosomal subunit, including Pdcd4-40S and Pdcd4-40S-eIF4A-eIF3-eIF1 complexes. The structures reveal the binding site of Pdcd4 at the mRNA entry site in the 40S, where the C-terminal domain (CTD) interacts with eIF4A at the mRNA entry site, while the N-terminal domain (NTD) is inserted into the mRNA channel and decoding site. The structures, together with quantitative binding and in vitro translation assays, shed light on the critical role of the NTD for the recruitment of Pdcd4 to the ribosomal complex and suggest a model whereby Pdcd4 blocks the eIF4F-independent role of eIF4A during recruitment and scanning of the 5' UTR of mRNA.
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Affiliation(s)
- Jailson Brito Querido
- MRC Laboratory of Molecular Biology, Cambridge, UK.
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA.
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA.
- Center for RNA Biomedicine, University of Michigan, Ann Arbor, MI, USA.
| | - Masaaki Sokabe
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, CA, USA
| | | | | | | | - Yifei Du
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | | | | | - Christopher S Fraser
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, CA, USA.
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2
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Cao B, Chen X, Li Y, Zhou T, Chen N, Guo Y, Zhao M, Guo C, Shi Y, Wang Q, Du X, Zhang L, Li Y. PDCD4 triggers α-synuclein accumulation and motor deficits via co-suppressing TFE3 and TFEB translation in a model of Parkinson's disease. NPJ Parkinsons Dis 2024; 10:146. [PMID: 39107320 PMCID: PMC11303393 DOI: 10.1038/s41531-024-00760-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
TFE3 and TFEB, as the master regulators of lysosome biogenesis and autophagy, are well characterized to enhance the synaptic protein α-synuclein degradation in protecting against Parkinson's disease (PD) and their levels are significantly decreased in the brain of PD patients. However, how TFE3 and TFEB are regulated during PD pathogenesis remains largely vague. Herein, we identified that programmed cell death 4 (PDCD4) promoted pathologic α-synuclein accumulation to facilitate PD development via suppressing both TFE3 and TFEB translation. Conversely, PDCD4 deficiency significantly augmented global and nuclear TFE3 and TFEB distributions to alleviate neurodegeneration in a mouse model of PD with overexpressing α-synuclein in the striatum. Mechanistically, like TFEB as we reported before, PDCD4 also suppressed TFE3 translation, rather than influencing its transcription and protein stability, to restrain its nuclear translocation and lysosomal functions, eventually leading to α-synuclein aggregation. We proved that the two MA3 domains of PDCD4 mediated the translational suppression of TFE3 through binding to its 5'-UTR of mRNA in an eIF-4A dependent manner. Based on this, we developed a blood-brain barrier penetrating RVG polypeptide modified small RNA drug against pdcd4 to efficiently prevent α-synuclein neurodegeneration in improving PD symptoms by intraperitoneal injections. Together, we suggest PDCD4 as a PD-risk protein to facilitate α-synuclein neurodegeneration via suppressing TFE3 and TFEB translation and further provide a potential small RNA drug against pdcd4 to treat PD by intraperitoneal injections.
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Affiliation(s)
- Baihui Cao
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xiaotong Chen
- Department of Immunology, School of Clinical and Basic Medical Sciences, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan, China
| | - Yubin Li
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Tian Zhou
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Nuo Chen
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yaxin Guo
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Ming Zhao
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Chun Guo
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Yongyu Shi
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Qun Wang
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Xuexiang Du
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China
| | - Lining Zhang
- Department of Immunology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China.
| | - Yan Li
- Department of Pathogen Biology, School of Basic Medical Science, Cheeloo College of Medicine, Shandong University, Jinan, China.
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3
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Ye X, Huang Z, Li Y, Wang M, Meng W, Miao M, Cheng J. Human tumor suppressor PDCD4 directly interacts with ribosomes to repress translation. Cell Res 2024; 34:522-525. [PMID: 38641729 PMCID: PMC11217289 DOI: 10.1038/s41422-024-00962-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/08/2024] [Indexed: 04/21/2024] Open
Affiliation(s)
- Xianwen Ye
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Zixuan Huang
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Yi Li
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Mengjiao Wang
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Wanyu Meng
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Maojian Miao
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China
| | - Jingdong Cheng
- Minhang Hospital & Institutes of Biomedical Sciences, Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism, Fudan University, Shanghai, China.
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4
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Apostolopoulos A, Kawamoto N, Chow SYA, Tsuiji H, Ikeuchi Y, Shichino Y, Iwasaki S. dCas13-mediated translational repression for accurate gene silencing in mammalian cells. Nat Commun 2024; 15:2205. [PMID: 38467613 PMCID: PMC10928199 DOI: 10.1038/s41467-024-46412-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 02/27/2024] [Indexed: 03/13/2024] Open
Abstract
Current gene silencing tools based on RNA interference (RNAi) or, more recently, clustered regularly interspaced short palindromic repeats (CRISPR)‒Cas13 systems have critical drawbacks, such as off-target effects (RNAi) or collateral mRNA cleavage (CRISPR‒Cas13). Thus, a more specific method of gene knockdown is needed. Here, we develop CRISPRδ, an approach for translational silencing, harnessing catalytically inactive Cas13 proteins (dCas13). Owing to its tight association with mRNA, dCas13 serves as a physical roadblock for scanning ribosomes during translation initiation and does not affect mRNA stability. Guide RNAs covering the start codon lead to the highest efficacy regardless of the translation initiation mechanism: cap-dependent, internal ribosome entry site (IRES)-dependent, or repeat-associated non-AUG (RAN) translation. Strikingly, genome-wide ribosome profiling reveals the ultrahigh gene silencing specificity of CRISPRδ. Moreover, the fusion of a translational repressor to dCas13 further improves the performance. Our method provides a framework for translational repression-based gene silencing in eukaryotes.
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Grants
- JP20H05784 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05278 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05734 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H04268 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP20H05786 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H02415 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20K07016 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23K05648 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP21K15023 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23KJ2175 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005h0001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- Pioneering Projects MEXT | RIKEN
- Pioneering Projects MEXT | RIKEN
- Exploratory Research Center on Life and Living Systems (ExCELLS), 23EX601
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Affiliation(s)
- Antonios Apostolopoulos
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Naohiro Kawamoto
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Siu Yu A Chow
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hitomi Tsuiji
- Education and Research Division of Pharmacy, School of Pharmacy, Aichi Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Yoshiho Ikeuchi
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
| | - Shintaro Iwasaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan.
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
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5
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Brito Querido J, Díaz-López I, Ramakrishnan V. The molecular basis of translation initiation and its regulation in eukaryotes. Nat Rev Mol Cell Biol 2024; 25:168-186. [PMID: 38052923 DOI: 10.1038/s41580-023-00624-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 12/07/2023]
Abstract
The regulation of gene expression is fundamental for life. Whereas the role of transcriptional regulation of gene expression has been studied for several decades, it has been clear over the past two decades that post-transcriptional regulation of gene expression, of which translation regulation is a major part, can be equally important. Translation can be divided into four main stages: initiation, elongation, termination and ribosome recycling. Translation is controlled mainly during its initiation, a process which culminates in a ribosome positioned with an initiator tRNA over the start codon and, thus, ready to begin elongation of the protein chain. mRNA translation has emerged as a powerful tool for the development of innovative therapies, yet the detailed mechanisms underlying the complex process of initiation remain unclear. Recent studies in yeast and mammals have started to shed light on some previously unclear aspects of this process. In this Review, we discuss the current state of knowledge on eukaryotic translation initiation and its regulation in health and disease. Specifically, we focus on recent advances in understanding the processes involved in assembling the 43S pre-initiation complex and its recruitment by the cap-binding complex eukaryotic translation initiation factor 4F (eIF4F) at the 5' end of mRNA. In addition, we discuss recent insights into ribosome scanning along the 5' untranslated region of mRNA and selection of the start codon, which culminates in joining of the 60S large subunit and formation of the 80S initiation complex.
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Affiliation(s)
- Jailson Brito Querido
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Irene Díaz-López
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
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6
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Salerno F, Howden AJM, Matheson LS, Gizlenci Ö, Screen M, Lingel H, Brunner-Weinzierl MC, Turner M. An integrated proteome and transcriptome of B cell maturation defines poised activation states of transitional and mature B cells. Nat Commun 2023; 14:5116. [PMID: 37612319 PMCID: PMC10447577 DOI: 10.1038/s41467-023-40621-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 08/03/2023] [Indexed: 08/25/2023] Open
Abstract
During B cell maturation, transitional and mature B cells acquire cell-intrinsic features that determine their ability to exit quiescence and mount effective immune responses. Here we use label-free proteomics to quantify the proteome of B cell subsets from the mouse spleen and map the differential expression of environmental sensing, transcription, and translation initiation factors that define cellular identity and function. Cross-examination of the full-length transcriptome and proteome identifies mRNAs related to B cell activation and antibody secretion that are not accompanied by detection of the encoded proteins. In addition, proteomic data further suggests that the translational repressor PDCD4 restrains B cell responses, in particular those from marginal zone B cells, to a T-cell independent antigen. In summary, our molecular characterization of B cell maturation presents a valuable resource to further explore the mechanisms underpinning the specialized functions of B cell subsets, and suggest the presence of 'poised' mRNAs that enable expedited B cell responses.
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Affiliation(s)
- Fiamma Salerno
- Immunology programme, The Babraham Institute, Cambridge, UK.
| | | | | | - Özge Gizlenci
- Immunology programme, The Babraham Institute, Cambridge, UK
| | - Michael Screen
- Immunology programme, The Babraham Institute, Cambridge, UK
| | - Holger Lingel
- Department of Experimental Pediatrics, Otto-von-Guericke-University, Magdeburg, Germany
| | | | - Martin Turner
- Immunology programme, The Babraham Institute, Cambridge, UK.
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7
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Zhai Q, Hou Y, Ye Y, Dai S, Guo G, Yang Q, Pang G, Wei Q. Expression pattern and prognostic value of key regulators for N7-methylguanosine RNA modification in prostate cancer. Acta Biochim Biophys Sin (Shanghai) 2023; 55:561-573. [PMID: 36810782 DOI: 10.3724/abbs.2023017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023] Open
Abstract
Alterations in the regulators of RNA methylation modifications, such as N7-methylguanosine (m7G), have been implicated in a variety of diseases. Therefore, the analysis and identification of disease-related m7G modification regulators will accelerate advances in understanding disease pathogenesis. However, the implications of alterations in the regulators of m7G modifications remain poorly understood in prostate adenocarcinoma. In the present study, we analyze the expression patterns of 29 m7G RNA modification regulators in prostate adenocarcinoma using The Cancer Genome Atlas (TCGA) and perform consistent clustering analysis of differentially expressed genes (DEGs). We find that 18 m7G-related genes are differentially expressed in tumor and normal tissues. In different cluster subgroups, DEGs are mainly enriched in tumorigenesis and tumor development. Furthermore, immune analyses demonstrate that patients in cluster 1 have significantly higher scores for stromal and immune cells, such as B cells, T cells, and macrophages. Then, a TCGA-related risk model is developed and successfully validated using a Gene Expression Omnibus external dataset. Two genes ( EIF4A1 and NCBP2) are determined to be prognostically significant. Most importantly, we construct tissue microarrays from 26 tumor specimens and 20 normal specimens, and further confirm that EIF4A1 and NCBP2 are associated with tumor progression and Gleason score. Therefore, we conclude that the m7G RNA methylation regulators may be involved in the poor prognosis of patients with prostate adenocarcinoma. The results of this study may provide support for exploring the underlying molecular mechanisms of m7G regulators, especially EIF4A1 and NCBP2.
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Affiliation(s)
- Qiliang Zhai
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.,Department of Urology, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Yan Hou
- Department of Anesthesiology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Yuedian Ye
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Sujuan Dai
- Department of Pathology, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Guangxiu Guo
- Department of Pathology, Ganzhou People's Hospital, Ganzhou 341000, China
| | - Qiao Yang
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Guofu Pang
- Department of Urology, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai 519000, China
| | - Qiang Wei
- Department of Urology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
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8
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Zhang L, Zhang Y, Zhang S, Qiu L, Zhang Y, Zhou Y, Han J, Xie J. Translational Regulation by eIFs and RNA Modifications in Cancer. Genes (Basel) 2022; 13:2050. [PMID: 36360287 PMCID: PMC9690228 DOI: 10.3390/genes13112050] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 10/25/2022] [Accepted: 11/04/2022] [Indexed: 11/04/2023] Open
Abstract
Translation is a fundamental process in all living organisms that involves the decoding of genetic information in mRNA by ribosomes and translation factors. The dysregulation of mRNA translation is a common feature of tumorigenesis. Protein expression reflects the total outcome of multiple regulatory mechanisms that change the metabolism of mRNA pathways from synthesis to degradation. Accumulated evidence has clarified the role of an increasing amount of mRNA modifications at each phase of the pathway, resulting in translational output. Translation machinery is directly affected by mRNA modifications, influencing translation initiation, elongation, and termination or altering mRNA abundance and subcellular localization. In this review, we focus on the translation initiation factors associated with cancer as well as several important RNA modifications, for which we describe their association with cancer.
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Affiliation(s)
- Linzhu Zhang
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
- The Third People’s Hospital of Chengdu, Clinical College of Southwest Jiao Tong University, Chengdu 610014, China
| | - Yaguang Zhang
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Su Zhang
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Lei Qiu
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yang Zhang
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Ying Zhou
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Junhong Han
- State Key Laboratory of Biotherapy, Frontiers Science Center for Disease-Related Molecular Network and Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jiang Xie
- School of Basic Medical Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China
- The Third People’s Hospital of Chengdu, Clinical College of Southwest Jiao Tong University, Chengdu 610014, China
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eIF4A3 Promotes RNA Viruses’ Replication by Inhibiting Innate Immune Responses. J Virol 2022; 96:e0151322. [PMID: 36314820 PMCID: PMC9683021 DOI: 10.1128/jvi.01513-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Production of type I IFN is pivotal for the cellular antiviral immunity. Virus infection leads to the activation of transcription factor IRF3 and subsequent production of type I IFN to eliminate viral infection.
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10
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Genome-Wide Identification and Expression Analysis of eIF Family Genes from Brassica rapa in Response to TuMV Resistance. PLANTS 2022; 11:plants11172248. [PMID: 36079630 PMCID: PMC9460045 DOI: 10.3390/plants11172248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 08/13/2022] [Accepted: 08/23/2022] [Indexed: 11/28/2022]
Abstract
Brassica rapa is one of the most important leafy vegetables worldwide, and has a long history of cultivation. However, it has not been possible to completely control the damage of turnip mosaic virus (TuMV), a serious virus in B. rapa, to production. In this study, the genome-wide identification and expression detection of eIF family genes from B. rapa in response to TuMV resistance were analyzed, including the identification of eIF family genes, chromosomal distribution, three-dimensional (3D) structure and sequence logo analyses, and the expression characterization as well as differential metabolite analysis of eIF family genes in resistant/susceptible lines, which may further prove the whole-genome tripling (WGT) event in B. rapa evolution and provide evidence for the functional redundancy and functional loss of multicopy eIF genes in evolution. A qRT-PCR analysis revealed that the relative expressions of eIF genes in a susceptible line (80461) were higher than those in a resistant line (80124), which may prove that, when TuMV infects host plants, the eIF genes can combine with the virus mRNA 5′ end cap structure and promote the initiation of virus mRNA translation in the susceptible B. rapa line. In addition, the metabolite substances were detected, the differences in metabolites between disease-resistant and disease-susceptible plants were mainly manifested by altered compounds such as flavonoids, jasmonic acid, salicylic acid, ketones, esters, etc., which inferred that the different metabolite regulations of eIF family genes and reveal the resistance mechanisms of eIF genes against TuMV in brassica crops. This study may lay a new theoretical foundation for revealing eIF family gene resistance to TuMV in B. rapa, as well as advancing our understanding of virus–host interactions.
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11
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Cai Q, Yang HS, Li YC, Zhu J. Dissecting the Roles of PDCD4 in Breast Cancer. Front Oncol 2022; 12:855807. [PMID: 35795053 PMCID: PMC9251513 DOI: 10.3389/fonc.2022.855807] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 05/12/2022] [Indexed: 11/29/2022] Open
Abstract
The human programmed cell death 4 (PDCD4) gene was mapped at chromosome 10q24 and encodes the PDCD4 protein comprised of 469 amino acids. PDCD4 inhibits protein translation PDCD4 inhibits protein translation to suppress tumor progression, and its expression is frequently decreased in breast cancer. PDCD4 blocks translation initiation complex by binding eIF4A via MA-3 domains or by directly binding 5’ mRNA internal ribosome entry sites with an RNA binding domain to suppress breast cancer progression and proliferation. Numerous regulators and biological processes including non-coding RNAs, proteasomes, estrogen, natural compounds and inflammation control PDCD4 expression in breast cancer. Loss of PDCD4 expression is also responsible for drug resistance in breast cancer. HER2 activation downregulates PDCD4 expression by activating MAPK, AKT, and miR-21 in aromatase inhibitor-resistant breast cancer cells. Moreover, modulating the microRNA/PDCD4 axis maybe an effective strategy for overcoming chemoresistance in breast cancer. Down-regulation of PDCD4 is significantly associated with short overall survival of patients, which suggests that PDCD4 may be an independent prognostic marker for breast cancer.
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Affiliation(s)
- Qian Cai
- Department of Geriatric Medicine, Qilu Hospital of Shandong University, Jinan, China
- Key Laboratory of Cardiovasular Proteomics of Shandong Province, Qilu Hospital of Shandong University, Jinan, China
| | - Hsin-Sheng Yang
- Department of Toxicology and Cancer Biology, Collage of Medicine, University of Kentucky, Lexington, KY, United States
| | - Yi-Chen Li
- Department of Breast Surgery, General Surgery, Qilu Hospital of Shandong University, Jinan, China
| | - Jiang Zhu
- Department of Breast Surgery, General Surgery, Qilu Hospital of Shandong University, Jinan, China
- *Correspondence: Jiang Zhu,
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12
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Mobbs GW, Aziz AA, Dix SR, Blackburn GM, Sedelnikova SE, Minshull TC, Dickman MJ, Baker PJ, Nathan S, Raih MF, Rice DW. Molecular basis of specificity and deamidation of eIF4A by Burkholderia Lethal Factor 1. Commun Biol 2022; 5:272. [PMID: 35347220 PMCID: PMC8960835 DOI: 10.1038/s42003-022-03186-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 02/17/2022] [Indexed: 12/22/2022] Open
Abstract
Burkholderiapseudomallei lethal factor 1 (BLF1) exhibits site-specific glutamine deamidase activity against the eukaryotic RNA helicase, eIF4A, thereby blocking mammalian protein synthesis. The structure of a complex between BLF1 C94S and human eIF4A shows that the toxin binds in the cleft between the two RecA-like eIF4A domains forming interactions with residues from both and with the scissile amide of the target glutamine, Gln339, adjacent to the toxin active site. The RecA-like domains adopt a radically twisted orientation compared to other eIF4A structures and the nature and position of conserved residues suggests this may represent a conformation associated with RNA binding. Comparison of the catalytic site of BLF1 with other deamidases and cysteine proteases reveals that they fall into two classes, related by pseudosymmetry, that present either the re or si faces of the target amide/peptide to the nucleophilic sulfur, highlighting constraints in the convergent evolution of their Cys-His active sites. The crystal structure of the toxin from the pathogenic bacterium Burkholderia pseudomallei in complex with its target, human eIF4A, provides insights into substrate specificity and may facilitate the design of inhibitors for the treatment of melioidosis.
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13
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Shirokikh NE. Translation complex stabilization on messenger RNA and footprint profiling to study the RNA responses and dynamics of protein biosynthesis in the cells. Crit Rev Biochem Mol Biol 2021; 57:261-304. [PMID: 34852690 DOI: 10.1080/10409238.2021.2006599] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
During protein biosynthesis, ribosomes bind to messenger (m)RNA, locate its protein-coding information, and translate the nucleotide triplets sequentially as codons into the corresponding sequence of amino acids, forming proteins. Non-coding mRNA features, such as 5' and 3' untranslated regions (UTRs), start sites or stop codons of different efficiency, stretches of slower or faster code and nascent polypeptide interactions can alter the translation rates transcript-wise. Most of the homeostatic and signal response pathways of the cells converge on individual mRNA control, as well as alter the global translation output. Among the multitude of approaches to study translational control, one of the most powerful is to infer the locations of translational complexes on mRNA based on the mRNA fragments protected by these complexes from endonucleolytic hydrolysis, or footprints. Translation complex profiling by high-throughput sequencing of the footprints allows to quantify the transcript-wise, as well as global, alterations of translation, and uncover the underlying control mechanisms by attributing footprint locations and sizes to different configurations of the translational complexes. The accuracy of all footprint profiling approaches critically depends on the fidelity of footprint generation and many methods have emerged to preserve certain or multiple configurations of the translational complexes, often in challenging biological material. In this review, a systematic summary of approaches to stabilize translational complexes on mRNA for footprinting is presented and major findings are discussed. Future directions of translation footprint profiling are outlined, focusing on the fidelity and accuracy of inference of the native in vivo translation complex distribution on mRNA.
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Affiliation(s)
- Nikolay E Shirokikh
- Division of Genome Sciences and Cancer, The John Curtin School of Medical Research, The Australian National University, Canberra, Australia
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14
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Meier K, Thorkelsson SR, Quemin ERJ, Rosenthal M. Hantavirus Replication Cycle-An Updated Structural Virology Perspective. Viruses 2021; 13:1561. [PMID: 34452426 PMCID: PMC8402763 DOI: 10.3390/v13081561] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/31/2021] [Accepted: 08/02/2021] [Indexed: 11/17/2022] Open
Abstract
Hantaviruses infect a wide range of hosts including insectivores and rodents and can also cause zoonotic infections in humans, which can lead to severe disease with possible fatal outcomes. Hantavirus outbreaks are usually linked to the population dynamics of the host animals and their habitats being in close proximity to humans, which is becoming increasingly important in a globalized world. Currently there is neither an approved vaccine nor a specific and effective antiviral treatment available for use in humans. Hantaviruses belong to the order Bunyavirales with a tri-segmented negative-sense RNA genome. They encode only five viral proteins and replicate and transcribe their genome in the cytoplasm of infected cells. However, many details of the viral amplification cycle are still unknown. In recent years, structural biology methods such as cryo-electron tomography, cryo-electron microscopy, and crystallography have contributed essentially to our understanding of virus entry by membrane fusion as well as genome encapsidation by the nucleoprotein. In this review, we provide an update on the hantavirus replication cycle with a special focus on structural virology aspects.
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Affiliation(s)
- Kristina Meier
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany;
| | - Sigurdur R. Thorkelsson
- Centre for Structural Systems Biology, Leibniz Institute for Experimental Virology, University of Hamburg, 22607 Hamburg, Germany;
| | - Emmanuelle R. J. Quemin
- Centre for Structural Systems Biology, Leibniz Institute for Experimental Virology, University of Hamburg, 22607 Hamburg, Germany;
| | - Maria Rosenthal
- Department of Virology, Bernhard Nocht Institute for Tropical Medicine, 20359 Hamburg, Germany;
- Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, 22525 Hamburg, Germany
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15
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Xu Y, Guo C, Pan W, Zhao C, Ding Y, Xie X, Wei Z, Sun Y, Yu C. Nephrotic-syndrome-associated mutation of KANK2 induces pathologic binding competition with physiological interactor KIF21A. J Biol Chem 2021; 297:100958. [PMID: 34274317 PMCID: PMC8368038 DOI: 10.1016/j.jbc.2021.100958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 05/17/2021] [Accepted: 07/09/2021] [Indexed: 10/25/2022] Open
Abstract
Nephrotic syndrome (NS) is a common kidney disorder caused by dysfunction of the glomerular filtration barrier. Some genetic mutations identified in NS patients cause amino acid substitutions of kidney ankyrin repeat-containing (KANK) proteins, which are scaffold proteins that regulate actin polymerization, microtubule targeting, and cell adhesion via binding to various molecules, including the kinesin motor protein KIF21A. However, the mechanisms by which these mutations lead to NS are unclear. Here, we unexpectedly found that the eukaryotic translation initiation factor 4A1 (eIF4A1) interacts with an NS-associated KANK2 mutant (S684F) but not the wild-type protein. Biochemical and structural analyses revealed that the pathological mutation induces abnormal binding of eIF4A1 to KANK2 at the physiological KIF21A-binding site. Competitive binding assays further indicated that eIF4A1 can compete with KIF21A to interact with the S684F mutant of KANK2. In cultured mouse podocytes, this S684F mutant interfered with the KANK2/KIF21A interaction by binding to eIF4A1, and failed to rescue the focal adhesion or cell adhesion that had been reduced or morphologically changed by KANK2 knockout. These structural, biochemical, and cellular results not only provide mechanistic explanations for the podocyte defects caused by the S684F mutation, but also show how a gain-of-binding mutation can lead to a loss-of-function effect.
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Affiliation(s)
- Yuqun Xu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Chen Guo
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Wenfei Pan
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Chan Zhao
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yanyan Ding
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Xingqiao Xie
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Zhiyi Wei
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China; Brain Research Center, Southern University of Science and Technology, Shenzhen, Guangdong, China.
| | - Ying Sun
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern Univeristy of Science and Technology, Shenzhen, Guangdong, China.
| | - Cong Yu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China; Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China; Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Department of Biology, Southern Univeristy of Science and Technology, Shenzhen, Guangdong, China.
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16
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Chen G, Li PH, He JY, Su YL, Chen HJ, Dong JD, Huang YH, Huang XH, Jiang YF, Qin QW, Sun HY. Molecular cloning, inducible expression with SGIV and Vibrio alginolyticus challenge, and function analysis of Epinephelus coioides PDCD4. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 119:104013. [PMID: 33465381 DOI: 10.1016/j.dci.2021.104013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/11/2021] [Accepted: 01/11/2021] [Indexed: 06/12/2023]
Abstract
Programmed cell death 4 (PDCD4) in mammals, a gene closely associated with apoptosis, is involved in many biological processes, such as cell aging, differentiation, regulation of cell cycle, and inflammatory response. In this study, grouper Epinephelus coioides PDCD4, EcPDCD4-1 and EcPDCD4-2, were obtained. The open reading frame (ORF) of EcPDCD4-1 is 1413 bp encoding 470 amino acids with a molecular mass of 52.39 kDa and a theoretical pI of 5.33. The ORF of EcPDCD4-2 is 1410 bp encoding 469 amino acids with a molecular mass of 52.29 kDa and a theoretical pI of 5.29. Both EcPDCD4-1 and EcPDCD4-2 proteins contain two conserved MA3 domains, and their mRNA were detected in all eight tissues of E. coioides by quantitative real-time PCR (qRT-PCR) with the highest expression in liver. The expressions of two EcPDCD4s were significantly up-regulated after Singapore grouper iridovirus (SGIV) or Vibrio alginolyticus infection. In addition, over-expression of EcPDCD4-1 or EcPDCD4-2 can inhibit the activity of the nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), and regulate SGIV-induced apoptosis. The results demonstrated that EcPDCD4s might play important roles in E. coioides tissues during pathogen-caused inflammation.
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Affiliation(s)
- Guo Chen
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China; Hainan Key Laboratory of Tropical Marine Biotechnology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China; Department of Laboratory, Jining No.1 People's Hospital; Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine, Shandong, 272111, PR China; Life Sciences Institute, Zhejiang University, Zhejiang Province, 310058, PR China
| | - Pin-Hong Li
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Jia-Yang He
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Yu-Ling Su
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - He-Jia Chen
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Jun-De Dong
- Hainan Key Laboratory of Tropical Marine Biotechnology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, PR China
| | - You-Hua Huang
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Xiao-Hong Huang
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China
| | - Yu-Feng Jiang
- Department of Laboratory, Jining No.1 People's Hospital; Postdoctoral Mobile Station of Shandong University of Traditional Chinese Medicine, Shandong, 272111, PR China.
| | - Qi-Wei Qin
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China.
| | - Hong-Yan Sun
- Joint Laboratory of Guangdong Province and Hong Kong Regions on Marine Bioresource Conservation and Exploitation, Guangdong Laboratory for Lingnan Modern Agriculture, College of Marine Sciences, South China Agricultural University, Guangzhou, 510642, Guangdong Province, PR China.
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17
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Lloyd JR, Hogan A, Paschalis V, Bellamy-Carter J, Bottley A, Seymour GB, Hayes CJ, Oldham NJ. Mapping the interaction between eukaryotic initiation factor 4A (eIF4A) and the inhibitor hippuristanol using carbene footprinting and mass spectrometry. Proteomics 2021; 21:e2000288. [PMID: 34028182 DOI: 10.1002/pmic.202000288] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 05/14/2021] [Accepted: 05/17/2021] [Indexed: 11/08/2022]
Abstract
Protein-ligand interactions are central to protein activity and cell functionality. Improved knowledge of these relationships greatly benefits our understanding of key biological processes and aids in rational drug design towards the treatment of clinically relevant diseases. Carbene footprinting is a recently developed mass spectrometry-based chemical labelling technique that provides valuable information relating to protein-ligand interactions, such as the mapping of binding sites and associated conformational change. Here, we show the application of carbene footprinting to the interaction between eIF4A helicase and a natural product inhibitor, hippuristanol, found in the coral Isis hippuris. Upon addition of hippuristanol we identified reduced carbene labelling (masking) in regions of eIF4A previously implicated in ligand binding. Additionally, we detected hippuristanol-associated increased carbene labelling (unmasking) around the flexible hinge region of eIF4A, indicating ligand-induced conformational change. This work represents further development of the carbene footprinting technique and demonstrates its potential in characterising medicinally relevant protein-ligand interactions.
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Affiliation(s)
- James R Lloyd
- School of Chemistry, University of Nottingham, Nottingham, UK
| | - Amy Hogan
- School of Chemistry, University of Nottingham, Nottingham, UK
| | - Vasileios Paschalis
- School of Chemistry, University of Nottingham, Nottingham, UK.,Department of Molecular and Cell Biology, University of Leicester, Leicester, UK
| | - Jeddidiah Bellamy-Carter
- School of Chemistry, University of Nottingham, Nottingham, UK.,School of Biosciences, University of Birmingham, Birmingham, UK
| | - Andrew Bottley
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire, UK
| | - Graham B Seymour
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, Sutton Bonington, Leicestershire, UK
| | | | - Neil J Oldham
- School of Chemistry, University of Nottingham, Nottingham, UK
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18
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WD Repeat Domain 77 Protein Regulates Translation of E2F1 and E2F3 mRNA. Mol Cell Biol 2020; 40:MCB.00302-20. [PMID: 33020149 DOI: 10.1128/mcb.00302-20] [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: 06/24/2020] [Accepted: 09/30/2020] [Indexed: 11/20/2022] Open
Abstract
WD repeat domain 77 protein (WDR77) is required for cellular proliferation of lung and prostate epithelial cells during earlier stages of development and is reactivated during prostate and lung tumorigenesis. WDR77 plays an essential role in prostate tumorigenesis and cell growth mediated by growth regulatory factors. Here, we identified E2F1 and E2F3 mRNAs as translational targets of WDR77. We demonstrated that WDR77 regulated the translation of E2F1 and E2F3 mRNAs through the 5' untranslated regions (UTRs) of E2F1 and E2F3 (E2F1/3) mRNAs. WDR77 physically interacted with programmed cell death 4 (PDCD4) that suppresses translation of mRNAs containing structured 5' UTRs by interacting with eukaryotic translation initiation factor 4A (eIF4A) and inhibiting its helicase activity. Further, we demonstrated that the interaction between WDR77 and PDCD4 prevented the binding of PDCD4 to eIF4A and relieved PDCD4's inhibitory effect on eIF4A1. Overall, our work reveals for the first time that WDR77 is directly involved in translational regulation of E2F1/3 mRNAs through their structured 5' UTRs, PDCD4, and eIF4A1 and provides novel insight into the cell growth controlled by WDR77.
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19
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Jiang SL, Mo JL, Peng J, Lei L, Yin JY, Zhou HH, Liu ZQ, Hong WX. Targeting translation regulators improves cancer therapy. Genomics 2020; 113:1247-1256. [PMID: 33189778 DOI: 10.1016/j.ygeno.2020.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 10/14/2020] [Accepted: 11/11/2020] [Indexed: 02/07/2023]
Abstract
Deregulation of protein synthesis may be involved in multiple aspects of cancer, such as gene expression, signal transduction and drive specific cell biological responses, resulting in promoting cancer growth, invasion and metastasis. Study the molecular mechanisms about translational control may help us to find more effective anti-cancer drugs and develop novel therapeutic opportunities. Recently, the researchers had focused on targeting translational machinery to overcome cancer, and various small molecular inhibitors targeting translation factors or pathways have been tested in clinical trials and exhibited improving outcomes in several cancer types. There is no doubt that an insight into the class of translation regulation protein would provide new target for pharmacologic intervention and further provide opportunities to develop novel anti-tumor therapeutic interventions. In this review, we summarized the developments of translational control in cancer survival and progression et al, and highlighted the therapeutic approach targeted translation regulation to overcome the cancer.
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Affiliation(s)
- Shi-Long Jiang
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Jun-Luan Mo
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China; Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Ji Peng
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Lin Lei
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China
| | - Ji-Ye Yin
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Hong-Hao Zhou
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China
| | - Zhao-Qian Liu
- Department of Clinical Pharmacology, Hunan Key Laboratory of Pharmacogenetics, and National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, PR China; Institute of Clinical Pharmacology, Engineering Research Center for applied Technology of Pharmacogenomics of Ministry of Education, Central South University, Changsha 410078, PR China.
| | - Wen-Xu Hong
- Shenzhen Center for Chronic Disease Control and Prevention, Shenzhen 518020, PR China.
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20
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Programmed cell death 4 modulates lysosomal function by inhibiting TFEB translation. Cell Death Differ 2020; 28:1237-1250. [PMID: 33100324 DOI: 10.1038/s41418-020-00646-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 12/27/2022] Open
Abstract
Transcription factor EB (TFEB) is a master regulator of autophagy and lysosomal biogenesis. The post-translational phosphorylation modulations of TFEB by mTOR and ERK signaling can determine its nucleocytoplasmic shuttling and activity in response to nutrient availability. However, regulations of TFEB at translational level are rarely known. Here, we found that programmed cell death 4 (PDCD4), a tumor suppressor, decreased levels of nuclear TFEB to inhibit lysosome biogenesis and function. Mechanistically, PDCD4 reduces global pool of TFEB by suppressing TFEB translation in an eIF4A-dependent manner, rather than influencing mTOR- and ERK2-dependnet TFEB nucleocytoplasmic shuttling. Both of MA3 domains within PDCD4 are required for TFEB translation inhibition. Furthermore, TFEB is required for PDCD4-mediated lysosomal function suppression. In the tumor microenvironment, PDCD4 deficiency promotes the anti-tumor effect of macrophage via enhancing TFEB expression. Our research reveals a novel PDCD4-dependent TFEB translational regulation and supports PDCD4 as a potential therapeutic target for lysosome dysfunction related diseases.
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21
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Abstract
The stage at which ribosomes are recruited to messenger RNAs (mRNAs) is an elaborate and highly regulated phase of protein synthesis. Upon completion of this step, a ribosome is positioned at an appropriate initiation codon and primed to synthesize the encoded polypeptide product. In most circumstances, this step commits the ribosome to translate the mRNA. We summarize the knowledge regarding the initiation factors implicated in this activity as well as review different mechanisms by which this process is conducted.
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Affiliation(s)
- Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada; , .,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3A 1A3, Canada.,Department of Oncology, McGill University, Montreal, Quebec H4A 3T2, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada; , .,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3A 1A3, Canada
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22
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General and Target-Specific DExD/H RNA Helicases in Eukaryotic Translation Initiation. Int J Mol Sci 2020; 21:ijms21124402. [PMID: 32575790 PMCID: PMC7352612 DOI: 10.3390/ijms21124402] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 06/17/2020] [Accepted: 06/18/2020] [Indexed: 12/19/2022] Open
Abstract
DExD (DDX)- and DExH (DHX)-box RNA helicases, named after their Asp-Glu-x-Asp/His motifs, are integral to almost all RNA metabolic processes in eukaryotic cells. They play myriad roles in processes ranging from transcription and mRNA-protein complex remodeling, to RNA decay and translation. This last facet, translation, is an intricate process that involves DDX/DHX helicases and presents a regulatory node that is highly targetable. Studies aimed at better understanding this family of conserved proteins have revealed insights into their structures, catalytic mechanisms, and biological roles. They have also led to the development of chemical modulators that seek to exploit their essential roles in diseases. Herein, we review the most recent insights on several general and target-specific DDX/DHX helicases in eukaryotic translation initiation.
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PDCD4 controls the G1/S-phase transition in a telomerase-immortalized epithelial cell line and affects the expression level and translation of multiple mRNAs. Sci Rep 2020; 10:2758. [PMID: 32066800 PMCID: PMC7026441 DOI: 10.1038/s41598-020-59678-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/27/2019] [Indexed: 12/11/2022] Open
Abstract
PDCD4, the protein encoded by the tumor suppressor gene PDCD4 (programmed cell death 4) has been implicated in the control of cellular transcription and translation by modulating the activity of specific transcription factors and suppressing the translation of mRNAs with structured 5′-UTRs. Most studies of human PDCD4 have employed tumor cell lines, possibly resulting in a biased picture of its role in normal cells. Here, we have studied the function of PDCD4 in a telomerase-immortalized human epithelial cell line. We show for the first time that PDCD4 is required for the G1/S-transition, demonstrating its crucial role in the cell cycle. Inhibition of p53-dependent activation of p21WAF1/CIP1 overrides the requirement for PDCD4 for the G1/S-transition, suggesting that PDCD4 counteracts basal p53 activity to prevent activation of the G1/S checkpoint by p53. Transcriptome and ribosome profiling data show that silencing of PDCD4 changes the expression levels and translation of many mRNAs, providing an unbiased view of the cellular processes that are affected by PDCD4 in an epithelial cell line. Our data identify PDCD4 as a key regulator of cell cycle- and DNA-related functions that are inhibited when it is silenced, suggesting that decreased expression of PDCD4 might contribute to tumor development by compromising genomic integrity.
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24
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Degradation of the Tumor Suppressor PDCD4 Is Impaired by the Suppression of p62/SQSTM1 and Autophagy. Cells 2020; 9:cells9010218. [PMID: 31952347 PMCID: PMC7016974 DOI: 10.3390/cells9010218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 01/10/2020] [Accepted: 01/11/2020] [Indexed: 02/07/2023] Open
Abstract
PDCD4 (programmed cell death 4) is a tumor suppressor that plays a crucial role in multiple cellular functions, such as the control of protein synthesis and transcriptional control of some genes, the inhibition of cancer invasion and metastasis. The expression of this protein is controlled by synthesis, such as via transcription and translation, and degradation by the ubiquitin-proteasome system. The mitogens, known as tumor promotors, EGF (epidermal growth factor) and TPA (12-O-tetradecanoylphorbol-13-acetate) stimulate the degradation of PDCD4 protein. However, the whole picture of PDCD4 degradation mechanisms is still unclear, we therefore investigated the relationship between PDCD4 and autophagy. The proteasome inhibitor MG132 and the autophagy inhibitor bafilomycin A1 were found to upregulate the PDCD4 levels. PDCD4 protein levels increased synergistically in the presence of both inhibitors. Knockdown of p62/SQSTM1 (sequestosome-1), a polyubiquitin binding partner, also upregulated the PDCD4 levels. P62 and LC3 (microtubule-associated protein 1A/1B-light chain 3)-II were co-immunoprecipitated by an anti-PDCD4 antibody. Colocalization particles of PDCD4, p62 and the autophagosome marker LC3 were observed and the colocalization areas increased in the presence of autophagy and/or proteasome inhibitor(s) in Huh7 cells. In ATG (autophagy related) 5-deficient Huh7 cells in which autophagy was impaired, the PDCD4 levels were increased at the basal levels and upregulated in the presence of autophagy inhibitors. Based on the above findings, we concluded that after phosphorylation in the degron and ubiquitination, PDCD4 is degraded by both the proteasome and autophagy systems.
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Mishra RK, Datey A, Hussain T. mRNA Recruiting eIF4 Factors Involved in Protein Synthesis and Its Regulation. Biochemistry 2019; 59:34-46. [DOI: 10.1021/acs.biochem.9b00788] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Rishi Kumar Mishra
- Department of Molecular Reproduction, Development and Genetics, Division of Biological Sciences, Indian Institute of Science, Bangalore 560012, India
| | - Ayushi Datey
- Department of Molecular Reproduction, Development and Genetics, Division of Biological Sciences, Indian Institute of Science, Bangalore 560012, India
| | - Tanweer Hussain
- Department of Molecular Reproduction, Development and Genetics, Division of Biological Sciences, Indian Institute of Science, Bangalore 560012, India
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26
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Jiang C, Tang Y, Ding L, Tan R, Li X, Lu J, Jiang J, Cui Z, Tang Z, Li W, Cao Z, Schneider-Poetsch T, Jiang W, Luo C, Ding Y, Liu J, Dang Y. Targeting the N Terminus of eIF4AI for Inhibition of Its Catalytic Recycling. Cell Chem Biol 2019; 26:1417-1426.e5. [DOI: 10.1016/j.chembiol.2019.07.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 05/26/2019] [Accepted: 07/23/2019] [Indexed: 12/12/2022]
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27
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Iwasaki S, Iwasaki W, Takahashi M, Sakamoto A, Watanabe C, Shichino Y, Floor SN, Fujiwara K, Mito M, Dodo K, Sodeoka M, Imataka H, Honma T, Fukuzawa K, Ito T, Ingolia NT. The Translation Inhibitor Rocaglamide Targets a Bimolecular Cavity between eIF4A and Polypurine RNA. Mol Cell 2019; 73:738-748.e9. [PMID: 30595437 PMCID: PMC6386617 DOI: 10.1016/j.molcel.2018.11.026] [Citation(s) in RCA: 109] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Revised: 07/23/2018] [Accepted: 11/15/2018] [Indexed: 01/17/2023]
Abstract
A class of translation inhibitors, exemplified by the natural product rocaglamide A (RocA), isolated from Aglaia genus plants, exhibits antitumor activity by clamping eukaryotic translation initiation factor 4A (eIF4A) onto polypurine sequences in mRNAs. This unusual inhibitory mechanism raises the question of how the drug imposes sequence selectivity onto a general translation factor. Here, we determined the crystal structure of the human eIF4A1⋅ATP analog⋅RocA⋅polypurine RNA complex. RocA targets the "bi-molecular cavity" formed characteristically by eIF4A1 and a sharply bent pair of consecutive purines in the RNA. Natural amino acid substitutions found in Aglaia eIF4As changed the cavity shape, leading to RocA resistance. This study provides an example of an RNA-sequence-selective interfacial inhibitor fitting into the space shaped cooperatively by protein and RNA with specific sequences.
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Affiliation(s)
- Shintaro Iwasaki
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan; Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo 277-8561, Japan.
| | - Wakana Iwasaki
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Mari Takahashi
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Ayako Sakamoto
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Chiduru Watanabe
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory for Structure-Based Molecular Design, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Stephen N Floor
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA; Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Koichi Fujiwara
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Mari Mito
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Kosuke Dodo
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Wako, Saitama 351-0198, Japan; RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
| | - Mikiko Sodeoka
- Synthetic Organic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Wako, Saitama 351-0198, Japan; RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
| | - Hiroaki Imataka
- Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2201, Japan
| | - Teruki Honma
- Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan; Laboratory for Structure-Based Molecular Design, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Kaori Fukuzawa
- School of Pharmacy and Pharmaceutical Sciences, Hoshi University, Shinagawa, Tokyo 142-8501, Japan
| | - Takuhiro Ito
- Laboratory for Translation Structural Biology, RIKEN Center for Biosystems Dynamics Research, Tsurumi-ku, Yokohama 230-0045, Japan; Division of Structural and Synthetic Biology, RIKEN Center for Life Science Technologies, Tsurumi-ku, Yokohama 230-0045, Japan.
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA.
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Wang Q, Yang HS. The role of Pdcd4 in tumour suppression and protein translation. Biol Cell 2018; 110:10.1111/boc.201800014. [PMID: 29806708 PMCID: PMC6261700 DOI: 10.1111/boc.201800014] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/03/2018] [Accepted: 05/13/2018] [Indexed: 01/07/2023]
Abstract
Programmed cell death 4 (Pdcd4), a tumour suppressor, is frequently down-regulated in various types of cancer. Pdcd4 has been demonstrated to efficiently suppress tumour promotion, progression and proliferation. The biochemical function of Pdcd4 is a protein translation inhibitor. Although the fact that Pdcd4 inhibits protein translation has been known for more than a decade, the mechanism by which Pdcd4 controls tumorigenesis through translational regulation of its target genes is still not fully understood. Recent studies show that Pdcd4 inhibits translation of stress-activated-protein kinase interacting protein 1 to suppress tumour invasion, depicting a picture of how Pdcd4 inhibits tumorigenesis through translational inhibition. Thus, understanding the mechanism of how Pdcd4 attenuates tumorigenesis by translational control should provide a new strategy for combating cancer.
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Affiliation(s)
- Qing Wang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, Kentucky
| | - Hsin-Sheng Yang
- Department of Toxicology and Cancer Biology, University of Kentucky, Lexington, Kentucky
- Markey Cancer Center, College of Medicine, University of Kentucky, Lexington, Kentucky
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29
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Aljahdali AZ, Foster KA, O'Doherty GA. The asymmetric syntheses of cryptocaryols A and B. Chem Commun (Camb) 2018; 54:3428-3435. [PMID: 29547218 DOI: 10.1039/c8cc00482j] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The recent total syntheses of cryptocaryols A and B are reviewed. These efforts include the correction of the initially assigned absolute and relative stereochemistry of this class of natural products. In addition to enabling the initial structure activity relationships for this class of natural products, these syntheses demonstrated the practical utility of several novel synthetic approaches.
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30
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Ali MU, Ur Rahman MS, Jia Z, Jiang C. Eukaryotic translation initiation factors and cancer. Tumour Biol 2017; 39:1010428317709805. [PMID: 28653885 DOI: 10.1177/1010428317709805] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Recent technological advancements have shown tremendous mechanistic accomplishments in our understanding of the mechanism of messenger RNA translation in eukaryotic cells. Eukaryotic messenger RNA translation is very complex process that includes four phases (initiation, elongation, termination, and ribosome recycling) and diverse mechanisms involving protein and non-protein molecules. Translation regulation is principally achieved during initiation step of translation, which is organized by multiple eukaryotic translation initiation factors. Eukaryotic translation initiation factor proteins help in stabilizing the formation of the functional ribosome around the start codon and provide regulatory mechanisms in translation initiation. Dysregulated messenger RNA translation is a common feature of tumorigenesis. Various oncogenic and tumor suppressive genes affect/are affected by the translation machinery, making the components of the translation apparatus promising therapeutic targets for the novel anticancer drug. This review provides details on the role of eukaryotic translation initiation factors in messenger RNA translation initiation, their contribution to onset and progression of tumor, and how dysregulated eukaryotic translation initiation factors can be used as a target to treat carcinogenesis.
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Affiliation(s)
- Muhammad Umar Ali
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Muhammad Saif Ur Rahman
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhenyu Jia
- 2 Institute of Occupational Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Cao Jiang
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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Tumor suppressor Pdcd4 attenuates Sin1 translation to inhibit invasion in colon carcinoma. Oncogene 2017; 36:6225-6234. [PMID: 28692058 PMCID: PMC5680133 DOI: 10.1038/onc.2017.228] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 05/22/2017] [Accepted: 06/01/2017] [Indexed: 12/16/2022]
Abstract
Programmed cell death 4 (Pdcd4), a tumor invasion suppressor, is frequently down-regulated in colorectal cancer and other cancers. In this study, we find that loss of Pdcd4 increases the activity of mammalian target of rapamycin complex 2 (mTORC2) and thereby upregulates Snail expression. Examining the components of mTORC2 showed that Pdcd4 knockdown increased the protein but not mRNA level of stress-activated-protein kinase interacting protein 1 (Sin1), which resulted from enhanced Sin1 translation. To understand how Pdcd4 regulates Sin1 translation, the SIN1 5’ untranslated region (5’UTR) was fused with luciferase reporter and named as 5’Sin1-Luc. Pdcd4 knockdown/knockout significantly increased the translation of 5’Sin1-Luc but not the control luciferase without the SIN1 5’UTR, suggesting that Sin1 5’UTR is necessary for Pdcd4 to inhibit Sin1 translation. Ectopic expression of wild type Pdcd4 and Pdcd4(157–469), a deletion mutant that binds to translation initiation factor 4A (eIF4A), sufficiently inhibited Sin1 translation, and thus suppressed mTORC2 kinase activity and invasion in colon tumor cells. By contrast, Pdcd4(157–469)(D253A,D418A), a mutant that does not bind to eIF4A, failed to inhibit Sin1 translation, and consequently failed to repress mTORC2 activity and invasion. In addition, directly inhibiting eIF4A with silvestrol significantly suppressed Sin1 translation and attenuated invasion. These results indicate that Pdcd4-inhibited Sin1 translation is through suppressing eIF4A, and functionally important for suppression of mTORC2 activity and invasion. Moreover, in colorectal cancer tissues, the Sin1 protein but not mRNA was significantly up-regulated while Pdcd4 protein was down-regulated, suggesting that loss of Pdcd4 might correlate with Sin1 protein level but not mRNA level in colorectal cancer patients. Taken together, our work reveals a novel mechanism by which Pdcd4 inhibits Sin1 translation to attenuatemTORC2 activity and thereby suppresses invasion.
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32
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Liu Y, Su D, Song T. Programmed cell death 4 inhibits proliferation and differentiation and induces apoptosis of human mesenchymal stem cells through suppressing the Wnt/β-catenin pathway. RSC Adv 2017. [DOI: 10.1039/c7ra02000g] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
PDCD4 was closely related to the proliferation and the apoptosis of OP-hMSCs in osteoporosis.
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Affiliation(s)
- Yang Liu
- Department of Endocrinology
- Huaihe Hospital of Henan University
- Kaifeng
- China
| | - Dongyue Su
- Department of Endocrinology
- Huaihe Hospital of Henan University
- Kaifeng
- China
| | - Tao Song
- Department of Orthopaedics
- The People's Liberation Army 155 Hospital
- Kaifeng
- China
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33
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Aoyama T, Fukao A, Fujiwara T. [Translational regulation is mediated by the cross-talk between the miRNA pathway and RNA binding proteins]. Nihon Yakurigaku Zasshi 2016; 147:346-350. [PMID: 27301308 DOI: 10.1254/fpj.147.346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
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34
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Olal D, Daumke O. Structure of the Hantavirus Nucleoprotein Provides Insights into the Mechanism of RNA Encapsidation. Cell Rep 2016; 14:2092-2099. [PMID: 26923588 DOI: 10.1016/j.celrep.2016.02.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 12/07/2015] [Accepted: 01/25/2016] [Indexed: 11/19/2022] Open
Abstract
Hantaviruses are etiological agents of life-threatening hemorrhagic fever with renal syndrome and hantavirus cardiopulmonary syndrome. The nucleoprotein (N) of hantavirus is essential for viral transcription and replication, thus representing an attractive target for therapeutic intervention. We have determined the crystal structure of hantavirus N to 3.2 Å resolution. The structure reveals a two-lobed, mostly α-helical structure that is distantly related to that of orthobunyavirus Ns. A basic RNA binding pocket is located at the intersection between the two lobes. We provide evidence that oligomerization is mediated by amino- and C-terminal arms that bind to the adjacent monomers. Based on these findings, we suggest a model for the oligomeric ribonucleoprotein (RNP) complex. Our structure provides mechanistic insights into RNA encapsidation in the genus Hantavirus and constitutes a template for drug discovery efforts aimed at combating hantavirus infections.
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Affiliation(s)
- Daniel Olal
- Crystallography, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Strasse 10, 13125 Berlin, Germany.
| | - Oliver Daumke
- Crystallography, Max Delbrück Center for Molecular Medicine, Robert-Rössle-Strasse 10, 13125 Berlin, Germany; Biochemie, Freie Universität Berlin, Takustrasse 6, 14195 Berlin, Germany.
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35
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Recruitment, Duplex Unwinding and Protein-Mediated Inhibition of the Dead-Box RNA Helicase Dbp2 at Actively Transcribed Chromatin. J Mol Biol 2016; 428:1091-1106. [PMID: 26876600 DOI: 10.1016/j.jmb.2016.02.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 01/26/2016] [Accepted: 02/02/2016] [Indexed: 02/07/2023]
Abstract
RNA helicases play fundamental roles in modulating RNA structures and facilitating RNA-protein (RNP) complex assembly in vivo. Previously, our laboratory demonstrated that the DEAD-box RNA helicase Dbp2 in Saccharomyces cerevisiae is required to promote efficient assembly of the co-transcriptionally associated mRNA-binding proteins Yra1, Nab2, and Mex67 onto poly(A)(+)RNA. We also found that Yra1 associates directly with Dbp2 and functions as an inhibitor of Dbp2-dependent duplex unwinding, suggestive of a cycle of unwinding and inhibition by Dbp2. To test this, we undertook a series of experiments to shed light on the order of events for Dbp2 in co-transcriptional mRNP assembly. We now show that Dbp2 is recruited to chromatin via RNA and forms a large, RNA-dependent complex with Yra1 and Mex67. Moreover, single-molecule fluorescence resonance energy transfer and bulk biochemical assays show that Yra1 inhibits unwinding in a concentration-dependent manner by preventing the association of Dbp2 with single-stranded RNA. This inhibition prevents over-accumulation of Dbp2 on mRNA and stabilization of a subset of RNA polymerase II transcripts. We propose a model whereby Yra1 terminates a cycle of mRNP assembly by Dbp2.
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36
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Zang T, Broszczak DA, Broadbent JA, Cuttle L, Lu H, Parker TJ. The biochemistry of blister fluid from pediatric burn injuries: proteomics and metabolomics aspects. Expert Rev Proteomics 2015; 13:35-53. [PMID: 26581649 DOI: 10.1586/14789450.2016.1122528] [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] [Indexed: 12/18/2022]
Abstract
Burn injury is a prevalent and traumatic event for pediatric patients. At present, the diagnosis of burn injury severity is subjective and lacks a clinically relevant quantitative measure. This is due in part to a lack of knowledge surrounding the biochemistry of burn injuries and that of blister fluid. A more complete understanding of the blister fluid biochemistry may open new avenues for diagnostic and prognostic development. Burn insult induces a highly complex network of signaling processes and numerous changes within various biochemical systems, which can ultimately be examined using proteome and metabolome measurements. This review reports on the current understanding of burn wound biochemistry and outlines a technical approach for 'omics' profiling of blister fluid from burn wounds of differing severity.
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Affiliation(s)
- Tuo Zang
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia.,c Wound Management Innovation Co-operative Research Centre , West End , Australia
| | - Daniel A Broszczak
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia.,c Wound Management Innovation Co-operative Research Centre , West End , Australia
| | - James A Broadbent
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia.,c Wound Management Innovation Co-operative Research Centre , West End , Australia
| | - Leila Cuttle
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia.,d Centre for Children's Burns and Trauma Research , Queensland University of Technology, Institute of Health and Biomedical Innovation at the Centre for Children's Health Research , South Brisbane , Australia
| | - Haitao Lu
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia
| | - Tony J Parker
- a Tissue Repair and Regeneration Program , Institute of Health and Biomedical Innovation , Kelvin Grove , Australia.,b School of Biomedical Sciences , Queensland University of Technology , Brisbane , Australia
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37
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Moura DMN, Reis CRS, Xavier CC, da Costa Lima TD, Lima RP, Carrington M, de Melo Neto OP. Two related trypanosomatid eIF4G homologues have functional differences compatible with distinct roles during translation initiation. RNA Biol 2015; 12:305-19. [PMID: 25826663 DOI: 10.1080/15476286.2015.1017233] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
In higher eukaryotes, eIF4A, eIF4E and eIF4G homologues interact to enable mRNA recruitment to the ribosome. eIF4G acts as a scaffold for these interactions and also interacts with other proteins of the translational machinery. Trypanosomatid protozoa have multiple homologues of eIF4E and eIF4G and the precise function of each remains unclear. Here, 2 previously described eIF4G homologues, EIF4G3 and EIF4G4, were further investigated. In vitro, both homologues bound EIF4AI, but with different interaction properties. Binding to distinct eIF4Es was also confirmed; EIF4G3 bound EIF4E4 while EIF4G4 bound EIF4E3, both these interactions required similar binding motifs. EIF4G3, but not EIF4G4, interacted with PABP1, a poly-A binding protein homolog. Work in vivo with Trypanosoma brucei showed that both EIF4G3 and EIF4G4 are cytoplasmic and essential for viability. Depletion of EIF4G3 caused a rapid reduction in total translation while EIF4G4 depletion led to changes in morphology but no substantial inhibition of translation. Site-directed mutagenesis was used to disrupt interactions of the eIF4Gs with either eIF4E or eIF4A, causing different levels of growth inhibition. Overall the results show that only EIF4G3, with its cap binding partner EIF4E4, plays a major role in translational initiation.
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Affiliation(s)
- Danielle M N Moura
- a Centro de Pesquisas Aggeu Magalhães; Fundação Oswaldo Cruz ; Campus UFPE; Recife , PE , Brazil
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Abstract
The original purification of the heterotrimeric eIF4F was published over 30 years ago (Grifo, J. A., Tahara, S. M., Morgan, M. A., Shatkin, A. J., and Merrick, W. C. (1983) J. Biol. Chem. 258, 5804-5810). Since that time, numerous studies have been performed with the three proteins specifically required for the translation initiation of natural mRNAs, eIF4A, eIF4B, and eIF4F. These have involved enzymatic and structural studies of the proteins and a number of site-directed mutagenesis studies. The regulation of translation exhibited through the mammalian target of rapamycin (mTOR) pathway is predominately seen as the phosphorylation of 4E-BP, an inhibitor of protein synthesis that functions by binding to the cap binding subunit of eIF4F (eIF4E). A hypothesis that requires the disassembly of eIF4F during translation initiation to yield free subunits (eIF4A, eIF4E, and eIF4G) is presented.
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Affiliation(s)
- William C Merrick
- From the Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4935
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39
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Abstract
Based on own translational research of the biochemical and hormonal effects of cow's milk consumption in humans, this review presents milk as a signaling system of mammalian evolution that activates the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), the pivotal regulator of translation. Milk, a mammary gland-derived secretory product, is required for species-specific gene-nutrient interactions that promote appropriate growth and development of the newborn mammal. This signaling system is highly conserved and tightly controlled by the lactation genome. Milk is sufficient to activate mTORC1, the crucial regulator of protein, lipid, and nucleotide synthesis orchestrating anabolism, cell growth and proliferation. To fulfill its mTORC1-activating function, milk delivers four key metabolic messengers: (1) essential branched-chain amino acids (BCAAs); (2) glutamine; (3) palmitic acid; and (4) bioactive exosomal microRNAs, which in a synergistical fashion promote mTORC1-dependent translation. In all mammals except Neolithic humans, postnatal activation of mTORC1 by milk intake is restricted to the postnatal lactation period. It is of critical concern that persistent hyperactivation of mTORC1 is associated with aging and the development of age-related disorders such as obesity, type 2 diabetes mellitus, cancer, and neurodegenerative diseases. Persistent mTORC1 activation promotes endoplasmic reticulum (ER) stress and drives an aimless quasi-program, which promotes aging and age-related diseases.
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40
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Programmed cell death 4 protein (Pdcd4) and homeodomain-interacting protein kinase 2 (Hipk2) antagonistically control translation of Hipk2 mRNA. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1564-73. [DOI: 10.1016/j.bbamcr.2015.03.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Revised: 03/11/2015] [Accepted: 03/14/2015] [Indexed: 12/29/2022]
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Hauk G, Bowman GD. Formation of a Trimeric Xpo1-Ran[GTP]-Ded1 Exportin Complex Modulates ATPase and Helicase Activities of Ded1. PLoS One 2015; 10:e0131690. [PMID: 26120835 PMCID: PMC4484809 DOI: 10.1371/journal.pone.0131690] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Accepted: 06/05/2015] [Indexed: 11/24/2022] Open
Abstract
The DEAD-box RNA helicase Ded1, which is essential in yeast and known as DDX3 in humans, shuttles between the nucleus and cytoplasm and takes part in several basic processes including RNA processing and translation. A key interacting partner of Ded1 is the exportin Xpo1, which together with the GTP-bound state of the small GTPase Ran, facilitates unidirectional transport of Ded1 out of the nucleus. Here we demonstrate that Xpo1 and Ran[GTP] together reduce the RNA-stimulated ATPase and helicase activities of Ded1. Binding and inhibition of Ded1 by Xpo1 depend on the affinity of the Ded1 nuclear export sequence (NES) for Xpo1 and the presence of Ran[GTP]. Association with Xpo1/Ran[GTP] reduces RNA-stimulated ATPase activity of Ded1 by increasing the apparent KM for the RNA substrate. Despite the increased KM, the Ded1:Xpo1:Ran[GTP] ternary complex retains the ability to bind single stranded RNA, suggesting that Xpo1/Ran[GTP] may modulate the substrate specificity of Ded1. These results demonstrate that, in addition to transport, exportins such as Xpo1 also have the capability to alter enzymatic activities of their cargo.
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Affiliation(s)
- Glenn Hauk
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - Gregory D. Bowman
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland, United States of America
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42
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Ozgur S, Buchwald G, Falk S, Chakrabarti S, Prabu JR, Conti E. The conformational plasticity of eukaryotic RNA-dependent ATPases. FEBS J 2015; 282:850-63. [PMID: 25645110 DOI: 10.1111/febs.13198] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 01/13/2015] [Accepted: 01/14/2015] [Indexed: 12/22/2022]
Abstract
RNA helicases are present in all domains of life and participate in almost all aspects of RNA metabolism, from transcription and processing to translation and decay. The diversity of pathways and substrates that they act on is reflected in the diversity of their individual functions, structures, and mechanisms. However, RNA helicases also share hallmark properties. At the functional level, they promote rearrangements of RNAs and RNP particles by coupling nucleic acid binding and release with ATP hydrolysis. At the molecular level, they contain two domains homologous to the bacterial RecA recombination protein. This conserved catalytic core is flanked by additional domains, which typically regulate the ATPase activity in cis. Binding to effector proteins targets or regulates the ATPase activity in trans. Structural and biochemical studies have converged on the plasticity of RNA helicases as a fundamental property that is used to control their timely activation in the cell. In this review, we focus on the conformational regulation of conserved eukaryotic RNA helicases.
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Affiliation(s)
- Sevim Ozgur
- Structural Cell Biology Department, Max Planck Institute of Biochemistry, Martinsried, Germany
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43
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Zhang Y, Wang Q, Chen L, Yang HS. Inhibition of p70S6K1 Activation by Pdcd4 Overcomes the Resistance to an IGF-1R/IR Inhibitor in Colon Carcinoma Cells. Mol Cancer Ther 2015; 14:799-809. [PMID: 25573956 DOI: 10.1158/1535-7163.mct-14-0648] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 12/31/2014] [Indexed: 12/31/2022]
Abstract
Agents targeting insulin-like growth factor 1 receptor (IGF-1R) are being actively examined in clinical trials. Although there has been some initial success of single-agent targeting IGF-1R, attempts in later studies failed because of resistance. This study aimed to understand the effects of programmed cell death 4 (Pdcd4) on the chemosensitivity of the IGF-1R inhibitor OSI-906 in colorectal cancer cells and the mechanism underlying this impact. Using OSI-906-resistant and -sensitive colorectal cancer cells, we found that the Pdcd4 level directly correlates with cell chemosensitivity to OSI-906. In addition, tumors derived from Pdcd4 knockdown cells resist the growth inhibitory effect of OSI-906 in a colorectal cancer xenograft mouse model. Moreover, Pdcd4 enhances the antiproliferative effect of OSI-906 in resistant cells through suppression of p70S6K1 activation. Knockdown of p70S6K1, but not p70S6K2, significantly increases the chemosensitivity of OSI-906 in cultured colorectal cancer cells. Furthermore, the combination of OSI-906 and PF-4708671, a p70S6K1 inhibitor, efficiently suppresses the growth of OSI-906-resistant colon tumor cells in vitro and in vivo. Taken together, activation of p70S6K1 that is inhibited by Pdcd4 is essential for resistance to the IGF-1R inhibitor in colon tumor cells, and the combinational treatment of OSI-906 and PF-4708671 results in enhanced antiproliferation effects in colorectal cancer cells in vitro and in vivo, providing a novel venue to overcome the resistance to the IGF-1R inhibitor in treating colorectal cancer.
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Affiliation(s)
- Yan Zhang
- Department of Cancer Biology and Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Qing Wang
- Department of Cancer Biology and Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky
| | - Li Chen
- Department of Biostatistics, College of Public Health, University of Kentucky, Lexington, Kentucky. Markey Cancer Center, College of medicine, University of Kentucky, Lexington, Kentucky
| | - Hsin-Sheng Yang
- Department of Cancer Biology and Toxicology, College of Medicine, University of Kentucky, Lexington, Kentucky. Markey Cancer Center, College of medicine, University of Kentucky, Lexington, Kentucky.
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44
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Fukaya T, Iwakawa HO, Tomari Y. MicroRNAs block assembly of eIF4F translation initiation complex in Drosophila. Mol Cell 2014; 56:67-78. [PMID: 25280104 DOI: 10.1016/j.molcel.2014.09.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Revised: 07/09/2014] [Accepted: 08/28/2014] [Indexed: 12/20/2022]
Abstract
miRNAs silence their complementary target mRNAs by translational repression as well as by poly(A) shortening and mRNA decay. In Drosophila, miRNAs are typically incorporated into Argonaute1 (Ago1) to form the effector complex called RNA-induced silencing complex (RISC). Ago1-RISC associates with a scaffold protein GW182, which recruits additional silencing factors. We have previously shown that miRNAs repress translation initiation by blocking formation of the 48S and 80S ribosomal complexes. However, it remains unclear how ribosome recruitment is impeded. Here, we examined the assembly of translation initiation factors on the target mRNA under repression. We show that Ago1-RISC induces dissociation of eIF4A, a DEAD-box RNA helicase, from the target mRNA without affecting 5' cap recognition by eIF4E in a manner independent of GW182. In contrast, direct tethering of GW182 promotes dissociation of both eIF4E and eIF4A. We propose that miRNAs act to block the assembly of the eIF4F complex during translation initiation.
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Affiliation(s)
- Takashi Fukaya
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan; Department of Medical Genome Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Hiro-Oki Iwakawa
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan
| | - Yukihide Tomari
- Institute of Molecular and Cellular Biosciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan; Department of Medical Genome Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0032, Japan.
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45
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Downregulation of microRNA-21 expression restrains non-small cell lung cancer cell proliferation and migration through upregulation of programmed cell death 4. Cancer Gene Ther 2014; 22:23-9. [PMID: 25477028 DOI: 10.1038/cgt.2014.66] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2014] [Revised: 11/10/2014] [Accepted: 11/10/2014] [Indexed: 12/19/2022]
Abstract
Preliminary studies showed that miR-21 is overexpressed in some human cancers. However, the role of miR-21 in cancer is still unclear and even controversial. Our purpose was to investigate the biological effects of miR-21 on A549 non-small cell lung cancer (NSCLC) cells and the underlying mechanisms of those effects. The expression of miR-21 was quantified in serum samples from patients with NSCLC. A549 cells were transfected with miR-NC-sponge or miR-21-sponge only, or with miR-21-sponge plus PDCD4 small-interfering RNA (siRNA). The expression of miR-21 and PDCD4 mRNA in transfected cells was quantified by real-time polymerase chain reaction and the expression of PDCD4 protein by Western blot. Cell proliferation, apoptosis, migration, and invasion assays were performed to determine the biological effects of miR-21 expression and PDCD4 inhibition. miR-21 was overexpressed in serum from patients with NSCLC. Reduced miR-21 expression was observed following transfection with miR-21-sponge in A549 NSCLC cells. Co-transfection of miR-21-sponge with PDCD4 siRNA upregulated miR-21 expression in these cells. PDCD4 mRNA and protein levels were increased 2.14-fold and 2.16-fold, respectively, following inhibition of miR-21 expression. Inhibition of miR-21 expression following transfection of miR-21-sponge reduced cell proliferation, migration, and invasion of A549 cells. Depletion of PDCD4 by siRNA transfection reversed the reduction of cell proliferation, migration, and invasion induced by inhibition of miR-21 in A549 cells. It indicates that miR-21 is highly expressed in patients with NSCLC and inhibition of miR-21 expression reduces proliferation, migration, and invasion of A549 cells by upregulating PDCD4 expression. Modulation of miR-21 or PDCD4 expression may provide a potentially novel therapeutic approach for NSCLC.
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46
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Akabayov SR, Akabayov B, Wagner G. Human translation initiation factor eIF4G1 possesses a low-affinity ATP binding site facing the ATP-binding cleft of eIF4A in the eIF4G/eIF4A complex. Biochemistry 2014; 53:6422-5. [PMID: 25255371 PMCID: PMC4204880 DOI: 10.1021/bi500600m] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Eukaryotic
translation initiation factor 4G (eIF4G) plays a crucial
role in translation initiation, serving as a scaffolding protein binding
several other initiation factors, other proteins, and RNA. Binding
of eIF4G to the ATP-dependent RNA helicase eukaryotic translation
initiation factor 4A (eIF4A) enhances the activity of eIF4A in solution
and in crowded environments. Previously, this activity enhancement
was solely attributed to eIF4G, conferring a closed, active conformation
upon eIF4A. Here we show that eIF4G contains a low-affinity binding
site at the entrance to the ATP-binding cleft on eIF4A, suggesting
that regulation of the local ATP concentration may be an additional
reason for the enhancement in activity.
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Affiliation(s)
- Sabine R Akabayov
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School , Longwood Avenue, Boston, Massachusetts 02115, United States
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Fehler O, Singh P, Haas A, Ulrich D, Müller JP, Ohnheiser J, Klempnauer KH. An evolutionarily conserved interaction of tumor suppressor protein Pdcd4 with the poly(A)-binding protein contributes to translation suppression by Pdcd4. Nucleic Acids Res 2014; 42:11107-18. [PMID: 25190455 PMCID: PMC4176178 DOI: 10.1093/nar/gku800] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The tumor suppressor protein programmed cell death 4 (Pdcd4) has been implicated in the translational regulation of specific mRNAs, however, the identities of the natural Pdcd4 target mRNAs and the mechanisms by which Pdcd4 affects their translation are not well understood. Pdcd4 binds to the eukaryotic translation initiation factor eIF4A and inhibits its helicase activity, which has suggested that Pdcd4 suppresses translation initiation of mRNAs containing structured 5′-untranslated regions. Recent work has revealed a second inhibitory mechanism, which is eIF4A-independent and involves direct RNA-binding of Pdcd4 to the target mRNAs. We have now identified the poly(A)-binding protein (PABP) as a novel direct interaction partner of Pdcd4. The ability to interact with PABP is shared between human and Drosophila Pdcd4, indicating that it has been highly conserved during evolution. Mutants of Pdcd4 that have lost the ability to interact with PABP fail to stably associate with ribosomal complexes in sucrose density gradients and to suppress translation, as exemplified by c-myb mRNA. Overall, our work identifies PABP as a novel functionally relevant Pdcd4 interaction partner that contributes to the regulation of translation by Pdcd4.
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Affiliation(s)
- Olesja Fehler
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Priyanka Singh
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Astrid Haas
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Diana Ulrich
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Jan P Müller
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Johanna Ohnheiser
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
| | - Karl-Heinz Klempnauer
- Institute for Biochemistry, Westfälische-Wilhelms-Universität Münster, Wilhelm-Klemm-Str. 2, D-48149 Münster, Germany
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van den Bosch MWM, Palsson-Mcdermott E, Johnson DS, O'Neill LAJ. LPS induces the degradation of programmed cell death protein 4 (PDCD4) to release Twist2, activating c-Maf transcription to promote interleukin-10 production. J Biol Chem 2014; 289:22980-22990. [PMID: 24982420 DOI: 10.1074/jbc.m114.573089] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Programmed cell death protein 4 (PDCD4) is a tumor suppressor and has also been shown to suppress production of the immunomodulatory cytokine IL-10. The precise role of PDCD4 in IL-10 induction in macrophages is still not fully understood. Incubation of macrophages with inhibitors of PI3K and mTOR blocked LPS-stimulated PDCD4 degradation and expression of c-Maf and IL-10 production. PDCD4 and the transcription factor Twist2 were shown to form a complex in untreated cells. LPS disrupted the complex allowing Twist2 to bind to the c-Maf promoter. PI3K and mTOR inhibitors prevented this disruption by stabilizing PDCD4 and thereby decreased Twist2 binding to the c-Maf promoter and induction of c-Maf mRNA. These results indicate a regulatory role for PDCD4 and Twist2 in LPS-induced IL-10 production in macrophages. LPS promotes PDCD4 degradation via a pathway involving PI3K and mTOR, releasing Twist2, which induces IL-10 via c-Maf.
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Affiliation(s)
- Mirjam W M van den Bosch
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland and.
| | - Eva Palsson-Mcdermott
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland and
| | - Derek S Johnson
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Luke A J O'Neill
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland and
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Cho JH, Kim YW, Keum YS. Sulforaphane suppresses LPS-induced or TPA-induced downregulation of PDCD4 in RAW 264.7 cells. Phytother Res 2014; 28:1606-11. [PMID: 24895206 DOI: 10.1002/ptr.5171] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 02/26/2014] [Accepted: 04/21/2014] [Indexed: 12/11/2022]
Abstract
Sulforaphane is a natural chemopreventive isothiocyanate and abundantly found in various cruciferous vegetables. Although chemopreventive activity of sulforaphane is well documented, the detailed biochemical mechanism(s), underlying how it regulates the protein translation process to antagonize pro-inflammatory responses are largely unclear. In the present study, we show that lipopolysaccharide (LPS) or 12-O-tetradecanoylphorbol-13-acetate (TPA) treatment reduces cellular levels of PDCD4, and this event is mediated by affecting both transcription and proteolysis in RAW 264.7 cells. We show that LPS-mediated or TPA-mediated PDCD4 downregulation is catalyzed by the activation of intracellular Akt1 or S6K1 kinases and that sulforaphane suppresses LPS-induced or TPA-induced Akt1 or S6K1 activation, thereby resulting in the attenuation of PDCD4 downregulation in RAW 264.7 cells. We propose that sulforaphane suppression of PDCD4 downregulation serves as a novel molecular mechanism to control proliferation in response to pro-inflammatory signals.
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Affiliation(s)
- Jong-Ho Cho
- College of Pharmacy, Dongguk University, 814-9 Siksa-dong, Goyang, Gyeonggi-do, 410-820, Korea
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50
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Sun Y, Atas E, Lindqvist LM, Sonenberg N, Pelletier J, Meller A. Single-molecule kinetics of the eukaryotic initiation factor 4AI upon RNA unwinding. Structure 2014; 22:941-8. [PMID: 24909782 DOI: 10.1016/j.str.2014.04.014] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/06/2014] [Accepted: 04/24/2014] [Indexed: 11/30/2022]
Abstract
The eukaryotic translation initiation factor 4AI (eIF4AI) is the prototypical DEAD-box RNA helicase. It has a "dumbbell" structure consisting of two domains connected by a flexible linker. Previous studies demonstrated that eIF4AI, in conjunction with eIF4H, bind to loop structures and repetitively unwind RNA hairpins. Here, we probe the conformational dynamics of eIF4AI in real time using single-molecule FRET. We demonstrate that eIF4AI/eIF4H complex can repetitively unwind RNA hairpins by transitioning between an eIF4AI "open" and a "closed" conformation using the energy derived from ATP hydrolysis. Our experiments directly track the conformational changes in the catalytic cycle of eIF4AI and eIF4H, and this correlates precisely with the kinetics of RNA unwinding. Furthermore, we show that the small-molecule eIF4A inhibitor hippuristanol locks eIF4AI in the closed conformation, thus efficiently inhibiting RNA unwinding. These results indicate that the large conformational changes undertaken by eIF4A during the helicase catalytic cycle are rate limiting.
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Affiliation(s)
- Yingjie Sun
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Evrim Atas
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA
| | - Lisa M Lindqvist
- Department of Medical Biology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Biochemistry and The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Jerry Pelletier
- Department of Biochemistry and The Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, QC H3G 1Y6, Canada
| | - Amit Meller
- Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA; Faculty of Biomedical Engineering, The Technion, Haifa 32000, Israel.
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