1
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Ietswaart R, Smalec BM, Xu A, Choquet K, McShane E, Jowhar ZM, Guegler CK, Baxter-Koenigs AR, West ER, Fu BXH, Gilbert L, Floor SN, Churchman LS. Genome-wide quantification of RNA flow across subcellular compartments reveals determinants of the mammalian transcript life cycle. Mol Cell 2024; 84:2765-2784.e16. [PMID: 38964322 PMCID: PMC11315470 DOI: 10.1016/j.molcel.2024.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 05/15/2024] [Accepted: 06/11/2024] [Indexed: 07/06/2024]
Abstract
Dissecting the regulatory mechanisms controlling mammalian transcripts from production to degradation requires quantitative measurements of mRNA flow across the cell. We developed subcellular TimeLapse-seq to measure the rates at which RNAs are released from chromatin, exported from the nucleus, loaded onto polysomes, and degraded within the nucleus and cytoplasm in human and mouse cells. These rates varied substantially, yet transcripts from genes with related functions or targeted by the same transcription factors and RNA-binding proteins flowed across subcellular compartments with similar kinetics. Verifying these associations uncovered a link between DDX3X and nuclear export. For hundreds of RNA metabolism genes, most transcripts with retained introns were degraded by the nuclear exosome, while the remaining molecules were exported with stable cytoplasmic lifespans. Transcripts residing on chromatin for longer had extended poly(A) tails, whereas the reverse was observed for cytoplasmic mRNAs. Finally, machine learning identified molecular features that predicted the diverse life cycles of mRNAs.
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Affiliation(s)
- Robert Ietswaart
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
| | - Brendan M Smalec
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Albert Xu
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Karine Choquet
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Erik McShane
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Ziad Mohamoud Jowhar
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Chantal K Guegler
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Autum R Baxter-Koenigs
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Emma R West
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | | | - Luke Gilbert
- Arc Institute, Palo Alto, CA 94305, USA; Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Urology, University of California, San Francisco, San Francisco, CA 94518, USA
| | - Stephen N Floor
- 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.
| | - L Stirling Churchman
- Department of Genetics, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.
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2
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Dai L, Tan Q, Li L, Lou N, Zheng C, Yang J, Huang L, Wang S, Luo R, Fan G, Xie T, Yao J, Zhang Z, Tang L, Shi Y, Han X. High-Throughput Antigen Microarray Identifies Longitudinal Prognostic Autoantibody for Chemoimmunotherapy in Advanced Non-Small Cell Lung Cancer. Mol Cell Proteomics 2024; 23:100749. [PMID: 38513890 PMCID: PMC11070596 DOI: 10.1016/j.mcpro.2024.100749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 02/03/2024] [Accepted: 03/18/2024] [Indexed: 03/23/2024] Open
Abstract
Chemoimmunotherapy has evolved as a standard treatment for advanced non-small cell lung cancer (aNSCLC). However, inevitable drug resistance has limited its efficacy, highlighting the urgent need for biomarkers of chemoimmunotherapy. A three-phase strategy to discover, verify, and validate longitudinal predictive autoantibodies (AAbs) for aNSCLC before and after chemoimmunotherapy was employed. A total of 528 plasma samples from 267 aNSCLC patients before and after anti-PD1 immunotherapy were collected, plus 30 independent formalin-fixed paraffin-embedded samples. Candidate AAbs were firstly selected using a HuProt high-density microarray containing 21,000 proteins in the discovery phase, followed by validation using an aNSCLC-focused microarray. Longitudinal predictive AAbs were chosen for ELISA based on responders versus non-responders comparison and progression-free survival (PFS) survival analysis. Prognostic markers were also validated using immunohistochemistry and publicly available immunotherapy datasets. We identified and validated a panel of two AAbs (MAX and DHX29) as pre-treatment biomarkers and another panel of two AAbs (MAX and TAPBP) as on-treatment predictive markers in aNSCLC patients undergoing chemoimmunotherapy. All three AAbs exhibited a positive correlation with early responses and PFS (p < 0.05). The kinetics of MAX AAb showed an increasing trend in responders (p < 0.05) and a tendency to initially increase and then decrease in non-responders (p < 0.05). Importantly, MAX protein and mRNA levels effectively discriminated PFS (p < 0.05) in aNSCLC patients treated with immunotherapy. Our results present a longitudinal analysis of changes in prognostic AAbs in aNSCLC patients undergoing chemoimmunotherapy.
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Affiliation(s)
- Liyuan Dai
- Department of Clinical Laboratory, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Qiaoyun Tan
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Lin Li
- Department of Pathology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ning Lou
- Department of Clinical Laboratory, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Cuiling Zheng
- Department of Clinical Laboratory, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Jianliang Yang
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Liling Huang
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Shasha Wang
- Department of Clinical Laboratory, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Rongrong Luo
- Department of Clinical Laboratory, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Guangyu Fan
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Tongji Xie
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Jiarui Yao
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Zhishang Zhang
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Le Tang
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China
| | - Yuankai Shi
- Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing Key Laboratory of Clinical Study on Anticancer Molecular Targeted Drugs, Beijing, China.
| | - Xiaohong Han
- Clinical Pharmacology Research Center, Peking Union Medical College Hospital, State Key Laboratory of Complex Severe and Rare Diseases, NMPA Key Laboratory for Clinical Research and Evaluation of Drug, Beijing Key Laboratory of Clinical PK & PD Investigation for Innovative Drugs, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
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3
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Xin BG, Huang LY, Yuan LG, Liu NN, Li HH, Ai X, Lei DS, Hou XM, Rety S, Xi XG. Structural insights into the N-terminal APHB domain of HrpA: mediating canonical and i-motif recognition. Nucleic Acids Res 2024; 52:3406-3418. [PMID: 38412313 PMCID: PMC11014265 DOI: 10.1093/nar/gkae138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 02/08/2024] [Accepted: 02/14/2024] [Indexed: 02/29/2024] Open
Abstract
RNA helicases function as versatile enzymes primarily responsible for remodeling RNA secondary structures and organizing ribonucleoprotein complexes. In our study, we conducted a systematic analysis of the helicase-related activities of Escherichia coli HrpA and presented the structures of both its apo form and its complex bound with both conventional and non-canonical DNAs. Our findings reveal that HrpA exhibits NTP hydrolysis activity and binds to ssDNA and ssRNA in distinct sequence-dependent manners. While the helicase core plays an essential role in unwinding RNA/RNA and RNA/DNA duplexes, the N-terminal extension in HrpA, consisting of three helices referred to as the APHB domain, is crucial for ssDNA binding and RNA/DNA duplex unwinding. Importantly, the APHB domain is implicated in binding to non-canonical DNA structures such as G-quadruplex and i-motif, and this report presents the first solved i-motif-helicase complex. This research not only provides comprehensive insights into the multifaceted roles of HrpA as an RNA helicase but also establishes a foundation for further investigations into the recognition and functional implications of i-motif DNA structures in various biological processes.
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Affiliation(s)
- Ben-Ge Xin
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ling-Yun Huang
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Ling-Gang Yuan
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Na-Nv Liu
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Hai-Hong Li
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Xia Ai
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Dong-Sheng Lei
- School of Physical Science and Technology, Electron Microscopy Centre of Lanzhou University, Lanzhou University, Lanzhou 730000, People's Republic of China
- Key Laboratory of Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University, Lanzhou 730000, People's Republic of China
| | - Xi-Miao Hou
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Stephane Rety
- LBMC, ENS de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allee d'Italie F-69364 Lyon, France
| | - Xu-Guang Xi
- College of Life Sciences, Northwest A&F University, Yangling, Shaanxi 712100, China
- Laboratoirede de Biologie et Pharmacologie Appliquée(LBPA), CNRS UMR8113, ENS Paris-Saclay, Université Paris-Saclay, F-91190 Gif-sur-Yvette, France
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4
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Fromont-Racine M, Khanna V, Jacquier A, Badis G. YLR419W is the homolog of the mammalian translation initiation factor DHX29. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001112. [PMID: 38585201 PMCID: PMC10997966 DOI: 10.17912/micropub.biology.001112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/07/2024] [Accepted: 02/20/2024] [Indexed: 04/09/2024]
Abstract
27 years after the yeast genome sequencing, the function of many ORFs remain unknown. Despite the evolutionary distance between human and yeast, homology with the conserved DEAH/DExH-box helicase domains allowed us to list DHX29, DHX36 and DHX57 as three putative homologs of the yeast Ylr419wp. Functional studies first linked the Ylr419w protein to the translating ribosome and cross-linking and analysis of cDNA (CRAC) experiments determined the precise region of Ylr419wp in contact with the ribosome. It corresponds to the loop of the h16 helix in the 18S rRNA designing the translation initiation factor DHX29, as the functional homolog of Ylr419wp.
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Affiliation(s)
- Micheline Fromont-Racine
- Cytoplasmic mRNA surveillance in yeast, Institut Pasteur, Paris, Île-de-France, France
- UMR3525, French National Centre for Scientific Research, Paris, Île-de-France, France
| | | | - Alain Jacquier
- Cytoplasmic mRNA surveillance in yeast, Institut Pasteur, Paris, Île-de-France, France
- UMR3525, French National Centre for Scientific Research, Paris, Île-de-France, France
| | - Gwenael Badis
- Cytoplasmic mRNA surveillance in yeast, Institut Pasteur, Paris, Île-de-France, France
- UMR3525, French National Centre for Scientific Research, Paris, Île-de-France, France
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5
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Liu N, Zhang H, Zhang C, Li Z, Huang L, Sun J, Qi J, Deng X, Huang N, Mu Y, Li Z, Tian H. DHX37 Is a Promising Prognostic Biomarker and a Therapeutic Target for Immunotherapy and Chemotherapy in HCC. Cancers (Basel) 2023; 15:5228. [PMID: 37958405 PMCID: PMC10648173 DOI: 10.3390/cancers15215228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/26/2023] [Accepted: 10/26/2023] [Indexed: 11/15/2023] Open
Abstract
DHX37, a member of the DEAD/H-box RNA helicase family, has been implicated in various diseases, including tumors. However, the biological characteristics and prognostic significance of DHX37 in HCC remain unclear. In this study, we use R software 3.6.3 and multiple bioinformatics analysis tools, such as GDSC, HPA, STRING, TISCH, and TIMER2, to analyze the characterization and function of DHX37 in HCC. In addition, Western blot (WB) and immunohistochemistry (IHC) based on clinical samples validated some of the findings. DHX37 was more highly expressed in HCC samples compared to adjacent non-tumor tissues. Higher DHX37 expression is correlated with various clinicopathological characteristics in HCC, including AFP, adjacent hepatic tissue inflammation, histologic grade, T stage, and pathologic stage. Survival analysis revealed that the high DHX37 group had significantly shorter overall survival (OS), progress-free interval (PFI), and disease-specific survival (DSS) compared to the low DHX37 group. By analyzing the correlation between DHX37 and the IC50 of chemotherapeutic drugs, the results showed that DHX37 expression level was negatively correlated with the IC50 of 11 chemotherapeutic drugs. Further analysis indicated that DHX37 and its co-expressed genes may play important roles in activating the cell cycle, DNA repair, chemokine signaling pathways, and regulating the immune response, which leads to a poor prognosis in HCC. High expression of DHX37 is an independent risk factor for poor prognosis in HCC, and DHX37 is expected to be a potential target to inhibit tumor progression. Targeting DHX37 may enhance chemotherapeutic drug sensitivity and immunotherapeutic efficacy in HCC.
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Affiliation(s)
- Nanbin Liu
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Hailong Zhang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Chunli Zhang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Zeyu Li
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Limin Huang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Jin Sun
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Junan Qi
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- The First Ward of Hepatobiliary Pancreatic and Spleen Surgery, Baoji Municipal Central Hospital, Baoji 721008, China
| | - Xi Deng
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Na Huang
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Yanhua Mu
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Zongfang Li
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
| | - Hongwei Tian
- National and Local Joint Engineering Research Center of Biodiagnosis and Biotherapy, The Second Affiliated Hospital of Xi’an Jiaotong University, Xi’an 710004, China; (N.L.); (H.Z.); (C.Z.); (Z.L.); (L.H.); (J.S.); (X.D.); (N.H.); (Y.M.)
- Shaanxi Provincial Clinical Research Center for Hepatic & Splenic Diseases, Xi’an 710004, China;
- Tumor and Immunology Center of Precision Medicine Institute, Xi’an Jiaotong University, Xi’an 710049, China
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6
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O'Sullivan MH, Fraser CS. Monitoring RNA restructuring in a human cell-free extract reveals eIF4A-dependent and eIF4A-independent unwinding activity. J Biol Chem 2023:104936. [PMID: 37331603 PMCID: PMC10362145 DOI: 10.1016/j.jbc.2023.104936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/20/2023] Open
Abstract
The canonical DEAD-box helicase, eIF4A, unwinds 5' UTR secondary structures to promote mRNA translation initiation. Growing evidence has indicated that other helicases, such as DHX29 and DDX3/ded1p, also function to promote the scanning of the 40S subunit on highly structured mRNAs. It is unknown how the relative contributions of eIF4A and other helicases regulate duplex unwinding on an mRNA to promote initiation. Here, we have adapted a real-time fluorescent duplex unwinding assay to monitor precisely helicase activity in the 5' UTR of a reporter mRNA that can be translated in a cell-free extract in parallel. We monitored the rate of 5' UTR-dependent duplex unwinding in the absence or presence of an eIF4A inhibitor (Hippuristanol), a dominant negative eIF4A (eIF4A-R362Q), or a mutant eIF4E (eIF4E-W73L) that can bind the m7G cap but not eIF4G. Our experiments reveal that the duplex unwinding activity in the cell-free extract is roughly evenly split between eIF4A-dependent and eIF4A-independent mechanisms. Importantly, we show that the robust eIF4A-independent duplex unwinding is not sufficient for translation. We also show that the m7G cap structure, and not the poly(A) tail, is the primary mRNA modification responsible for promoting duplex unwinding in our cell-free extract system. Overall, the fluorescent duplex unwinding assay provides a precise method to investigate how eIF4A-dependent and eIF4A-independent helicase activity regulates translation initiation in cell-free extracts. We anticipate that potential small molecule inhibitors could be tested for helicase inhibition using this duplex unwinding assay.
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Affiliation(s)
- Mattie H O'Sullivan
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, CA 95616
| | - Christopher S Fraser
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of California, Davis, CA 95616.
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7
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Malaguarnera R, Gabriele C, Santamaria G, Giuliano M, Vella V, Massimino M, Vigneri P, Cuda G, Gaspari M, Belfiore A. Comparative proteomic analysis of insulin receptor isoform A and B signaling. Mol Cell Endocrinol 2022; 557:111739. [PMID: 35940390 DOI: 10.1016/j.mce.2022.111739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/17/2022] [Accepted: 07/28/2022] [Indexed: 11/30/2022]
Abstract
The insulin receptor (IR) gene undergoes differential splicing generating two IR isoforms, IR-A and IR-B. The roles of IR-A in cancer and of IR-B in metabolic regulation are well known but the molecular mechanisms responsible for their different biological effects are poorly understood. We aimed to identify different or similar protein substrates and signaling linked to each IR isoforms. We employed mouse fibroblasts lacking IGF1R gene and expressing exclusively either IR-A or IR-B. By proteomic analysis a total of 2530 proteins were identified and quantified. Proteins and pathways mostly associated with insulin-activated IR-A were involved in cancer, stemness and interferon signaling. Instead, proteins and pathways associated with insulin-stimulated IR-B-expressing cells were mostly involved in metabolic or tumor suppressive functions. These results show that IR-A and IR-B recruit partially different multiprotein complexes in response to insulin, suggesting partially different functions of IR isoforms in physiology and in disease.
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Affiliation(s)
| | - Caterina Gabriele
- Research Centre for Advanced Biochemistry and Molecular Biology, Department of Experimental and Clinical Medicine, "Magna Græcia" University of Catanzaro, 88100, Catanzaro, Italy.
| | - Gianluca Santamaria
- Research Centre for Advanced Biochemistry and Molecular Biology, Department of Experimental and Clinical Medicine, "Magna Græcia" University of Catanzaro, 88100, Catanzaro, Italy; Klinikum rechts der Isar, Department of Medicine and Molecular Cardiology, Technical University of Munich, Germany.
| | - Marika Giuliano
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Catania, Garibaldi-Nesima Hospital, 95122, Catania, Italy.
| | - Veronica Vella
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Catania, Garibaldi-Nesima Hospital, 95122, Catania, Italy.
| | - Michele Massimino
- Department of Clinical and Experimental Medicine, Oncology Unit, University of Catania, 95100, Catania, Italy.
| | - Paolo Vigneri
- Department of Clinical and Experimental Medicine, Oncology Unit, University of Catania, 95100, Catania, Italy.
| | - Giovanni Cuda
- Research Centre for Advanced Biochemistry and Molecular Biology, Department of Experimental and Clinical Medicine, "Magna Græcia" University of Catanzaro, 88100, Catanzaro, Italy.
| | - Marco Gaspari
- Research Centre for Advanced Biochemistry and Molecular Biology, Department of Experimental and Clinical Medicine, "Magna Græcia" University of Catanzaro, 88100, Catanzaro, Italy.
| | - Antonino Belfiore
- Unit of Endocrinology, Department of Clinical and Experimental Medicine, University of Catania, Garibaldi-Nesima Hospital, 95122, Catania, Italy.
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8
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Wilkins KC, Venkataramanan S, Floor SN. Lysate and cell-based assays to probe the translational role of RNA helicases. Methods Enzymol 2022; 673:141-168. [DOI: 10.1016/bs.mie.2022.03.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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DEAD/H-box helicases:Anti-viral and pro-viral roles during infections. Virus Res 2021; 309:198658. [PMID: 34929216 DOI: 10.1016/j.virusres.2021.198658] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 11/26/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023]
Abstract
DEAD/H-box RNA helicases make the prominent family of helicases super family-2 which take part in almost all RNA-related processes, from initiation of transcription to RNA decay pathways. In addition to these RNA-related activities, in recent years a certain number of these helicases are reported to play important roles in anti-viral immunity through various ways. Along with RLHs, endosomal TLRs, and cytosolic DNA receptors, many RNA helicases including DDX3, DHX9, DDX6, DDX41, DHX33, DDX60, DHX36 and DDX1-DDX21-DHX36 complex act as viral nucleic acid sensors or co-sensors. These helicases mostly follow RLHs-MAVS and STING mediated signaling cascades to trigger induction of type-I interferons and pro-inflammatory cytokines. Many of them also function as downstream adaptor molecules (DDX3), segments of stress and processing bodies (DDX3 and DDX6) or negative regulators (DDX19, DDX24, DDX25, DDX39A and DDX46). On the contrary, many studies indicated that several DEAD/H-box helicases such as DDX1, DDX3, DDX6, DDX24, and DHX9 could be exploited by viruses to evade innate immune responses, suggesting that these helicases seem to have a dual function as anti-viral innate immune mediators and viral replication cofactors. In this review, we summarized the current knowledge on several representative DEAD/H-box helicases, with an emphasis on their functions in innate immunity responses, involved in their anti-viral and pro-viral roles.
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10
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Sweeney TR, Dhote V, Guca E, Hellen CUT, Hashem Y, Pestova T. Functional role and ribosomal position of the unique N-terminal region of DHX29, a factor required for initiation on structured mammalian mRNAs. Nucleic Acids Res 2021; 49:12955-12969. [PMID: 34883515 PMCID: PMC8682770 DOI: 10.1093/nar/gkab1192] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/12/2021] [Accepted: 11/22/2021] [Indexed: 02/05/2023] Open
Abstract
Translation initiation on structured mammalian mRNAs requires DHX29, a DExH protein that comprises a unique 534-aa-long N-terminal region (NTR) and a common catalytic DExH core. DHX29 binds to 40S subunits and possesses 40S-stimulated NTPase activity essential for its function. In the cryo-EM structure of DHX29-bound 43S preinitiation complexes, the main DHX29 density resides around the tip of helix 16 of 18S rRNA, from which it extends through a linker to the subunit interface forming an intersubunit domain next to the eIF1A binding site. Although a DExH core model can be fitted to the main density, the correlation between the remaining density and the NTR is unknown. Here, we present a model of 40S-bound DHX29, supported by directed hydroxyl radical cleavage data, showing that the intersubunit domain comprises a dsRNA-binding domain (dsRBD, aa 377-448) whereas linker corresponds to the long α-helix (aa 460-512) that follows the dsRBD. We also demonstrate that the N-terminal α-helix and the following UBA-like domain form a four-helix bundle (aa 90-166) that constitutes a previously unassigned section of the main density and resides between DHX29's C-terminal α-helix and the linker. In vitro reconstitution experiments revealed the critical and specific roles of these NTR elements for DHX29's function.
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Affiliation(s)
- Trevor R Sweeney
- Correspondence may also be addressed to Trevor R. Sweeney. Tel: +44 1483232441; Fax: +44 1483232448;
| | | | - Ewelina Guca
- INSERM U1212 Acides nucléiques : Régulations Naturelle et Artificielle (ARNA), Institut Européen de Chimie et Biologie, Université de Bordeaux, Pessac 33607, France
| | - Christopher U T Hellen
- Department of Cell Biology, SUNY Downstate Health Sciences University, 450 Clarkson Avenue, MSC 44, Brooklyn, NY 11203, USA
| | - Yaser Hashem
- Correspondence may also be addressed to Yaser Hashem. Tel: +33 5 40 00 88 22;
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11
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Zhang X, Groen K, Morten BC, Steffens Reinhardt L, Campbell HG, Braithwaite AW, Bourdon JC, Avery-Kiejda KA. Effect of p53 and its N-terminally truncated isoform, Δ40p53, on breast cancer migration and invasion. Mol Oncol 2021; 16:447-465. [PMID: 34657382 PMCID: PMC8763661 DOI: 10.1002/1878-0261.13118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Revised: 08/27/2021] [Accepted: 10/14/2021] [Indexed: 01/07/2023] Open
Abstract
Breast cancer is the most diagnosed malignancy in women, with over half a million women dying from this disease each year. In our previous studies, ∆40p53, an N‐terminally truncated p53 isoform, was found to be upregulated in breast cancers, and a high ∆40p53 : p53α ratio was linked with worse disease‐free survival. Although p53α inhibits cancer migration and invasion, little is known about the role of ∆40p53 in regulating these metastasis‐related processes and its role in contributing to worse prognosis. The aim of this study was to assess the role of ∆40p53 in breast cancer migration and invasion. A relationship between Δ40p53 and gene expression profiles was identified in oestrogen‐receptor‐positive breast cancer specimens. To further evaluate the role of Δ40p53 in oestrogen‐receptor‐positive breast cancer, MCF‐7 and ZR75‐1 cell lines were transduced to knockdown p53α or Δ40p53 and overexpress Δ40p53. Proliferation, migration and invasion were assessed in the transduced sublines, and gene expression was assessed through RNA‐sequencing and validated by reverse‐transcription quantitative PCR. Knockdown of both p53α and ∆40p53 resulted in increased proliferation, whereas overexpression of ∆40p53 reduced proliferation rates. p53α knockdown was also associated with increased cell mobility. ∆40p53 overexpression reduced both migratory and invasive properties of the transduced cells. Phenotypic findings are supported by gene expression data, including differential expression of LRG1, HYOU1, UBE2QL1, SERPINA5 and PCDH7. Taken together, these results suggest that, at the basal level, ∆40p53 works similarly to p53α in suppressing cellular mobility and proliferation, although the role of Δ40p53 may be cell context‐specific.
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Affiliation(s)
- Xiajie Zhang
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, NSW, Australia
| | - Kira Groen
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, NSW, Australia
| | - Brianna C Morten
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, NSW, Australia
| | - Luiza Steffens Reinhardt
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, NSW, Australia
| | - Hamish G Campbell
- Children's Medical Research Institute, University of Sydney, NSW, Australia
| | - Antony W Braithwaite
- Children's Medical Research Institute, University of Sydney, NSW, Australia.,Department of Pathology, School of Medicine, University of Otago, Dunedin, New Zealand
| | | | - Kelly A Avery-Kiejda
- Hunter Medical Research Institute, New Lambton Heights, NSW, Australia.,School of Biomedical Sciences and Pharmacy, College of Health, Medicine and Wellbeing, The University of Newcastle, NSW, Australia
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12
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A CRISPR knockout screen reveals new regulators of canonical Wnt signaling. Oncogenesis 2021; 10:63. [PMID: 34552058 PMCID: PMC8458386 DOI: 10.1038/s41389-021-00354-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 08/18/2021] [Accepted: 09/01/2021] [Indexed: 12/18/2022] Open
Abstract
The Wnt signaling pathways play fundamental roles during both development and adult homeostasis. Aberrant activation of the canonical Wnt signal transduction pathway is involved in many diseases including cancer, and is especially implicated in the development and progression of colorectal cancer. Although extensively studied, new genes, mechanisms and regulatory modulators involved in Wnt signaling activation or silencing are still being discovered. Here we applied a genome-scale CRISPR-Cas9 knockout (KO) screen based on Wnt signaling induced cell survival to reveal new inhibitors of the oncogenic, canonical Wnt pathway. We have identified several potential Wnt signaling inhibitors and have characterized the effects of the initiation factor DExH-box protein 29 (DHX29) on the Wnt cascade. We show that KO of DHX29 activates the Wnt pathway leading to upregulation of the Wnt target gene cyclin-D1, while overexpression of DHX29 inhibits the pathway. Together, our data indicate that DHX29 may function as a new canonical Wnt signaling tumor suppressor and demonstrates that this screening approach can be used as a strategy for rapid identification of novel Wnt signaling modulators.
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13
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Burgers LD, Fürst R. Natural products as drugs and tools for influencing core processes of eukaryotic mRNA translation. Pharmacol Res 2021; 170:105535. [PMID: 34058326 DOI: 10.1016/j.phrs.2021.105535] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 12/19/2022]
Abstract
Eukaryotic protein synthesis is the highly conserved, complex mechanism of translating genetic information into proteins. Although this process is essential for cellular homoeostasis, dysregulations are associated with cellular malfunctions and diseases including cancer and diabetes. In the challenging and ongoing search for adequate treatment possibilities, natural products represent excellent research tools and drug leads for new interactions with the translational machinery and for influencing mRNA translation. In this review, bacterial-, marine- and plant-derived natural compounds that interact with different steps of mRNA translation, comprising ribosomal assembly, translation initiation and elongation, are highlighted. Thereby, the exact binding and interacting partners are unveiled in order to accurately understand the mode of action of each natural product. The pharmacological relevance of these compounds is furthermore assessed by evaluating the observed biological activities in the light of translational inhibition and by enlightening potential obstacles and undesired side-effects, e.g. in clinical trials. As many of the natural products presented here possess the potential to serve as drug leads for synthetic derivatives, structural motifs, which are indispensable for both mode of action and biological activities, are discussed. Evaluating the natural products emphasises the strong diversity of their points of attack. Especially the fact that selected binding partners can be set in direct relation to different diseases emphasises the indispensability of natural products in the field of drug development. Discovery of new, unique and unusual interacting partners again renders them promising tools for future research in the field of eukaryotic mRNA translation.
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Affiliation(s)
- Luisa D Burgers
- Institute of Pharmaceutical Biology, Faculty of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany
| | - Robert Fürst
- Institute of Pharmaceutical Biology, Faculty of Biochemistry, Chemistry and Pharmacy, Goethe University, Frankfurt, Germany; LOEWE Center for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt, Germany
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14
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Graifer D, Karpova G. Ribosomal protein uS3 in cell biology and human disease: Latest insights and prospects. Bioessays 2020; 42:e2000124. [PMID: 33179285 DOI: 10.1002/bies.202000124] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/14/2020] [Indexed: 12/20/2022]
Abstract
The conserved ribosomal protein uS3 in eukaryotes has long been known as one of the essential components of the small (40S) ribosomal subunit, which is involved in the structure of the 40S mRNA entry pore, ensuring the functioning of the 40S subunit during translation initiation. Besides, uS3, being outside the ribosome, is engaged in various cellular processes related to DNA repair, NF-kB signaling pathway and regulation of apoptosis. This review is devoted to recent data opening new horizons in understanding the roles of uS3 in such processes as the assembly and maturation of 40S subunits, ensuring proper structure of 48S pre-initiation complexes, regulation of initiation and ribosome-based RNA quality control pathways. Besides, we summarize novel results on the participation of the protein in processes beyond translation and consider biomedical implications of previously known and recently found extra-ribosomal functions of uS3, primarily, in oncogenesis.
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Affiliation(s)
- Dmitri Graifer
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
| | - Galina Karpova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, Novosibirsk, Russia
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15
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Xu S, Feng W, Lu Z, Yu CY, Shao W, Nakshatri H, Reiter JL, Gao H, Chu X, Wang Y, Liu Y. regSNPs-ASB: A Computational Framework for Identifying Allele-Specific Transcription Factor Binding From ATAC-seq Data. Front Bioeng Biotechnol 2020; 8:886. [PMID: 32850739 PMCID: PMC7405637 DOI: 10.3389/fbioe.2020.00886] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 07/09/2020] [Indexed: 12/21/2022] Open
Abstract
Expression quantitative trait loci (eQTL) analysis is useful for identifying genetic variants correlated with gene expression, however, it cannot distinguish between causal and nearby non-functional variants. Because the majority of disease-associated SNPs are located in regulatory regions, they can impact allele-specific binding (ASB) of transcription factors and result in differential expression of the target gene alleles. In this study, our aim was to identify functional single-nucleotide polymorphisms (SNPs) that alter transcriptional regulation and thus, potentially impact cellular function. Here, we present regSNPs-ASB, a generalized linear model-based approach to identify regulatory SNPs that are located in transcription factor binding sites. The input for this model includes ATAC-seq (assay for transposase-accessible chromatin with high-throughput sequencing) raw read counts from heterozygous loci, where differential transposase-cleavage patterns between two alleles indicate preferential transcription factor binding to one of the alleles. Using regSNPs-ASB, we identified 53 regulatory SNPs in human MCF-7 breast cancer cells and 125 regulatory SNPs in human mesenchymal stem cells (MSC). By integrating the regSNPs-ASB output with RNA-seq experimental data and publicly available chromatin interaction data from MCF-7 cells, we found that these 53 regulatory SNPs were associated with 74 potential target genes and that 32 (43%) of these genes showed significant allele-specific expression. By comparing all of the MCF-7 and MSC regulatory SNPs to the eQTLs in the Genome-Tissue Expression (GTEx) Project database, we found that 30% (16/53) of the regulatory SNPs in MCF-7 and 43% (52/122) of the regulatory SNPs in MSC were also in eQTL regions. The enrichment of regulatory SNPs in eQTLs indicated that many of them are likely responsible for allelic differences in gene expression (chi-square test, p-value < 0.01). In summary, we conclude that regSNPs-ASB is a useful tool for identifying causal variants from ATAC-seq data. This new computational tool will enable efficient prioritization of genetic variants identified as eQTL for further studies to validate their causal regulatory function. Ultimately, identifying causal genetic variants will further our understanding of the underlying molecular mechanisms of disease and the eventual development of potential therapeutic targets.
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Affiliation(s)
- Siwen Xu
- Institute of Intelligent System and Bioinformatics, College of Automation, Harbin Engineering University, Harbin, China.,Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Weixing Feng
- Institute of Intelligent System and Bioinformatics, College of Automation, Harbin Engineering University, Harbin, China
| | - Zixiao Lu
- Regenstrief Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Christina Y Yu
- Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Biomedical Informatics, The Ohio State University, Columbus, OH, United States
| | - Wei Shao
- Regenstrief Institute, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Harikrishna Nakshatri
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Jill L Reiter
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Hongyu Gao
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Xiaona Chu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yue Wang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
| | - Yunlong Liu
- Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, United States.,Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, United States
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16
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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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17
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Brumwell A, Fell L, Obress L, Uniacke J. Hypoxia influences polysome distribution of human ribosomal protein S12 and alternative splicing of ribosomal protein mRNAs. RNA (NEW YORK, N.Y.) 2020; 26:361-371. [PMID: 31911497 PMCID: PMC7025504 DOI: 10.1261/rna.070318.119] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Accepted: 01/02/2020] [Indexed: 06/10/2023]
Abstract
Ribosomes were once considered static in their composition because of their essential role in protein synthesis and kingdom-wide conservation. The existence of tolerated mutations in select ribosomal proteins (RPs), such as in Diamond-Blackfan anemia, is evidence that not all ribosome components are essential. Heterogeneity in the protein composition of eukaryotic ribosomes is an emerging concept with evidence that different pools of ribosomes exist with transcript-specificity. Here, we show that the polysome association of ribosomal proteins is altered by low oxygen (hypoxia), a feature of the tumor microenvironment, in human cells. We quantified ribosomal protein abundance in actively translating polysomes of normoxic and hypoxic HEK293 cells by tandem mass tags mass spectrometry. Our data suggest that RPS12 (eS12) is enriched in hypoxic monosomes, which increases the heavy polysome association of structured transcripts APAF-1 and XIAP. Furthermore, hypoxia induced five alternative splicing events within a subset of RP mRNAs in cell lines. One of these events in RPS24 (eS24 protein) alters the coding sequence to produce two protein isoforms that can incorporate into ribosomes. This splicing event is greatly induced in spheroids and correlates with tumor hypoxia in human prostate cancer. Our data suggest that hypoxia may influence the composition of the human ribosome through changes in RP incorporation and the production of hypoxia-specific RP isoforms.
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Affiliation(s)
- Andrea Brumwell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Leslie Fell
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Lindsay Obress
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - James Uniacke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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18
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de Wispelaere M, Carocci M, Burri DJ, Neidermyer WJ, Olson CM, Roggenbach I, Liang Y, Wang J, Whelan SPJ, Gray NS, Yang PL. A broad-spectrum antiviral molecule, QL47, selectively inhibits eukaryotic translation. J Biol Chem 2020; 295:1694-1703. [PMID: 31914414 PMCID: PMC7008383 DOI: 10.1074/jbc.ra119.011132] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 12/16/2019] [Indexed: 12/13/2022] Open
Abstract
Small-molecule inhibitors of translation are critical tools to study the molecular mechanisms of protein synthesis. In this study, we sought to characterize how QL47, a host-targeted, small-molecule antiviral agent, inhibits steady-state viral protein expression. We demonstrate that this small molecule broadly inhibits both viral and host protein synthesis and targets a translation step specific to eukaryotic cells. We show that QL47 inhibits protein neosynthesis initiated by both canonical cap-driven and noncanonical initiation strategies, most likely by targeting an early step in translation elongation. Our findings thus establish QL47 as a new small-molecule inhibitor that can be utilized to probe the eukaryotic translation machinery and that can be further developed as a new therapeutic agent.
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Affiliation(s)
- Mélissanne de Wispelaere
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Margot Carocci
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Dominique J Burri
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - William J Neidermyer
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Calla M Olson
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Imme Roggenbach
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Yanke Liang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Jinhua Wang
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Sean P J Whelan
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115
| | - Nathanael S Gray
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, Massachusetts 02215
| | - Priscilla L Yang
- Department of Microbiology and Blavatnik Institute, Harvard Medical School, Boston, Massachusetts 02115.
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19
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Waldron JA, Tack DC, Ritchey LE, Gillen SL, Wilczynska A, Turro E, Bevilacqua PC, Assmann SM, Bushell M, Le Quesne J. mRNA structural elements immediately upstream of the start codon dictate dependence upon eIF4A helicase activity. Genome Biol 2019; 20:300. [PMID: 31888698 PMCID: PMC6936103 DOI: 10.1186/s13059-019-1901-2] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/26/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The RNA helicase eIF4A1 is a key component of the translation initiation machinery and is required for the translation of many pro-oncogenic mRNAs. There is increasing interest in targeting eIF4A1 therapeutically in cancer, thus understanding how this protein leads to the selective re-programming of the translational landscape is critical. While it is known that eIF4A1-dependent mRNAs frequently have long GC-rich 5'UTRs, the details of how 5'UTR structure is resculptured by eIF4A1 to enhance the translation of specific mRNAs are unknown. RESULTS Using Structure-seq2 and polysome profiling, we assess global mRNA structure and translational efficiency in MCF7 cells, with and without eIF4A inhibition with hippuristanol. We find that eIF4A inhibition does not lead to global increases in 5'UTR structure, but rather it leads to 5'UTR remodeling, with localized gains and losses of structure. The degree of these localized structural changes is associated with 5'UTR length, meaning that eIF4A-dependent mRNAs have greater localized gains of structure due to their increased 5'UTR length. However, it is not solely increased localized structure that causes eIF4A-dependency but the position of the structured regions, as these structured elements are located predominantly at the 3' end of the 5'UTR. CONCLUSIONS By measuring changes in RNA structure following eIF4A inhibition, we show that eIF4A remodels local 5'UTR structures. The location of these structural elements ultimately determines the dependency on eIF4A, with increased structure just upstream of the CDS being the major limiting factor in translation, which is overcome by eIF4A activity.
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Affiliation(s)
- Joseph A Waldron
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
| | - David C Tack
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
- Department of Chemistry, Pennsylvania State University, University Park, PA, 16802, USA
- Present Address: Spectrum Health Office of Research, 100 Michigan Street NE, Mail Code 038, Grand Rapids, MI, 49503, USA
| | - Laura E Ritchey
- Department of Chemistry, Pennsylvania State University, University Park, PA, 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
- Present Address: Department of Chemistry, University of Pittsburgh at Johnstown, Johnstown, PA, 15904, USA
| | - Sarah L Gillen
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Ania Wilczynska
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK
| | - Ernest Turro
- Department of Haematology, University of Cambridge, Cambridge, UK
- Medical Research Council Biostatistics Unit, Cambridge Institute of Public Health, Cambridge, UK
- National Health Service Blood and Transplant, Cambridge, UK
- National Institute for Health Research BioResource, Cambridge University Hospitals, Cambridge, UK
| | - Philip C Bevilacqua
- Department of Chemistry, Pennsylvania State University, University Park, PA, 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biochemistry & Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Sarah M Assmann
- Department of Biology, Pennsylvania State University, University Park, PA, 16802, USA
- Center for RNA Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Martin Bushell
- Cancer Research UK Beatson Institute, Garscube Estate, Switchback Road, Glasgow, G61 1BD, UK.
- Institute of Cancer Sciences, University of Glasgow, Garscube Estate, Switchback Road, Glasgow, G61 1QH, UK.
| | - John Le Quesne
- Medical Research Council Toxicology Unit, University of Cambridge, Hodgkin Building, Lancaster Road, Leicester, LE1 7HB, UK.
- Leicester Cancer Research Centre, University of Leicester, Leicester, UK.
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20
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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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21
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Rath S, Prangley E, Donovan J, Demarest K, Wingreen NS, Meir Y, Korennykh A. Concerted 2-5A-Mediated mRNA Decay and Transcription Reprogram Protein Synthesis in the dsRNA Response. Mol Cell 2019; 75:1218-1228.e6. [PMID: 31494033 DOI: 10.1016/j.molcel.2019.07.027] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 06/13/2019] [Accepted: 07/16/2019] [Indexed: 01/09/2023]
Abstract
Viral and endogenous double-stranded RNA (dsRNA) is a potent trigger for programmed RNA degradation by the 2-5A/RNase L complex in cells of all mammals. This 2-5A-mediated decay (2-5AMD) is a conserved stress response switching global protein synthesis from homeostasis to production of interferons (IFNs). To understand this mechanism, we examined 2-5AMD in human cells and found that it triggers polysome collapse characteristic of inhibited translation initiation. We determined that translation initiation complexes and ribosomes purified from translation-arrested cells remain functional. However, spike-in RNA sequencing (RNA-seq) revealed cell-wide decay of basal mRNAs accompanied by rapid accumulation of mRNAs encoding innate immune proteins. Our data attribute this 2-5AMD evasion to better stability of defense mRNAs and positive feedback in the IFN response amplified by RNase L-resistant molecules. We conclude that 2-5AMD and transcription act in concert to refill mammalian cells with defense mRNAs, thereby "prioritizing" the synthesis of innate immune proteins.
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Affiliation(s)
- Sneha Rath
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Eliza Prangley
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Jesse Donovan
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Kaitlin Demarest
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Ned S Wingreen
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
| | - Yigal Meir
- Department of Physics, Ben Gurion University, Beer-Sheva 84105, Israel
| | - Alexei Korennykh
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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22
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Cheng MSQ, Su MXX, Wang MXN, Sun MZY, Ou TM. Probes and drugs that interfere with protein translation via targeting to the RNAs or RNA-protein interactions. Methods 2019; 167:124-133. [PMID: 31185274 DOI: 10.1016/j.ymeth.2019.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 04/08/2019] [Accepted: 06/05/2019] [Indexed: 11/18/2022] Open
Abstract
Protein synthesis is critical to cell survival and translation regulation is essential to post-transcriptional gene expression regulation. Disorders of this process, particularly through RNA-binding proteins, is associated with the development and progression of a number of diseases, including cancers. However, the molecular mechanisms underlying the initiation of protein synthesis are intricate, making it difficult to find a drug that interferes with this process. Chemical probes are useful in elucidating the structures of RNA-protein complex and molecular mechanism of biological events. Moreover, some of these chemical probes show certain therapeutic benefits and can be further developed as leading compounds. Here, we will briefly review the general process and mechanism of protein synthesis, and emphasis on chemical probes in examples of probing the RNA structural changes and RNA-protein interactions. Moreover, the therapeutic potential of these probes is also discussed to give a comprehensive understanding.
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Affiliation(s)
- Miss Sui-Qi Cheng
- Sun Yat-Sen University, School of Pharmaceutical Sciences, Guangzhou, Guangdong 510006, China
| | - Miss Xiao-Xuan Su
- Sun Yat-Sen University, School of Pharmaceutical Sciences, Guangzhou, Guangdong 510006, China.
| | - Miss Xiao-Na Wang
- Sun Yat-Sen University, School of Pharmaceutical Sciences, Guangzhou, Guangdong 510006, China
| | - Miss Zhi-Yin Sun
- Sun Yat-Sen University, School of Pharmaceutical Sciences, Guangzhou, Guangdong 510006, China
| | - Tian-Miao Ou
- Sun Yat-Sen University, School of Pharmaceutical Sciences, 132 Waihuan East Road, Guangzhou University City, Guangzhou, Guangdong, China.
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23
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Arya AK, Bhadada SK, Singh P, Dahiya D, Kaur G, Sharma S, Saikia UN, Behera A, Rao SD, Bhasin M. Quantitative proteomics analysis of sporadic parathyroid adenoma tissue samples. J Endocrinol Invest 2019; 42:577-590. [PMID: 30284223 DOI: 10.1007/s40618-018-0958-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Accepted: 09/19/2018] [Indexed: 12/18/2022]
Abstract
OBJECTIVE Molecular pathogenesis of parathyroid tumors is incompletely understood. Identification of novel molecules and understanding their role in parathyroid tumorigenesis by proteomics approach would be informative with potential clinical implications. METHOD Adenomatous (n = 5) and normal (n = 2) parathyroid tissue lysates were analyzed for protein profile by LC-MS/MS method and the proteins were classified using bioinformatics tools such as PANTHER and toppfun functional enrichment tool. Identified proteins were further validated by western blotting and qRT-PCR (n = 20). RESULT Comparative proteomics analysis revealed that a total of 206 proteins (74 upregulated and 132 downregulated) were differentially expressed (≥ twofold change) in adenomas. Bioinformatics analysis revealed that 48 proteins were associated with plasma membrane, 49 with macromolecular complex, 39 were cytoplasm, 38 were organelle related, 21 were cell junction and 10 were extracellular proteins. These proteins belonged to a diverse protein family such as enzymes, transcription factors, cell signalling, cell adhesion, cytoskeleton proteins, receptors, and calcium-binding proteins. The major biological processes predicted for the proteins were a cellular, metabolic and developmental process, cellular localization, and biological regulation. The differentially expressed proteins were found to be associated with MAPK, phospholipase C (PLC) and phosphatidylinositol (PI) signalling pathways, and with chromatin organization. Western blot and qRT-PCR analysis of three proteins (DNAJC2, ACO2, and PRDX2) validated the LC-MS/MS findings. CONCLUSION This exploratory study demonstrates the feasibility of proteomics approach in finding the dysregulated proteins in benign parathyroid adenomas, and our preliminary results suggest that MAPK, PLC and PI signalling pathways and chromatin organization are involved in parathyroid tumorigenesis.
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Affiliation(s)
- A K Arya
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Room No. 2, 4th Floor Block-F, Nehru Hospital, PGIMER, Chandigarh, 160012, India
| | - S K Bhadada
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Room No. 2, 4th Floor Block-F, Nehru Hospital, PGIMER, Chandigarh, 160012, India.
| | - P Singh
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Room No. 2, 4th Floor Block-F, Nehru Hospital, PGIMER, Chandigarh, 160012, India
| | - D Dahiya
- Department of General Surgery, PGIMER, Chandigarh, India
| | - G Kaur
- Department of Endocrinology, Postgraduate Institute of Medical Education and Research (PGIMER), Room No. 2, 4th Floor Block-F, Nehru Hospital, PGIMER, Chandigarh, 160012, India
| | - S Sharma
- Department of Biochemistry, PGIMER, Chandigarh, India
| | - U N Saikia
- Department of Histopathology, PGIMER, Chandigarh, India
| | - A Behera
- Department of General Surgery, PGIMER, Chandigarh, India
| | - S D Rao
- Bone and Mineral Research Laboratory, Henry Ford Hospital, Detroit, USA
| | - M Bhasin
- Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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24
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Abstract
In the past 4 years, because of the advent of new cameras, many ribosome structures have been solved by cryoelectron microscopy (cryo-EM) at high, often near-atomic resolution, bringing new mechanistic insights into the processes of translation initiation, peptide elongation, termination, and recycling. Thus, cryo-EM has joined X-ray crystallography as a powerful technique in structural studies of translation. The significance of this new development is that structures of ribosomes in complex with their functional binding partners can now be determined to high resolution in multiple states as they perform their work. The aim of this article is to provide an overview of these new studies and assess the contributions they have made toward an understanding of translation and translational control.
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25
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Zhu Q, Tan P, Li Y, Lin M, Li C, Mao J, Cui J, Zhao W, Wang HY, Wang RF. DHX29 functions as an RNA co-sensor for MDA5-mediated EMCV-specific antiviral immunity. PLoS Pathog 2018; 14:e1006886. [PMID: 29462185 PMCID: PMC5834211 DOI: 10.1371/journal.ppat.1006886] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 03/02/2018] [Accepted: 01/18/2018] [Indexed: 12/13/2022] Open
Abstract
Melanoma differentiation-associated gene-5 (MDA5) recognizes distinct subsets of viruses including Encephalomyocarditis virus (EMCV) of picornavirus family, but the molecular mechanisms underlying the specificity of the viral recognition of MDA5 in immune cells remain obscure. DHX29 is an RNA helicase required for the translation of 5’ structured mRNA of host and many picornaviruses (such as EMCV). We identify that DXH29 as a key RNA co-sensor, plays a significant role for specific recognition and triggering anti-EMCV immunity. We have observed that DHX29 regulates MDA5-, but not RIG-I-, mediated type I interferon signaling by preferentially interacting with structured RNAs and specifically with MDA5 for enhancing MDA5-dsRNA binding affinity. Overall, our results identify a critical role for DHX29 in innate immune response and provide molecular insights into the mechanisms by which DHX29 recognizes 5’ structured EMCV RNA and interacts with MDA5 for potent type I interferon signaling and antiviral immunity. Cytosolic sensor melanoma differentiation-associated gene-5 (MDA5) specifically detects long-duplex RNAs in the genome of double-stranded (ds)RNA viruses such as Encephalomyocarditis virus (EMCV) whereas retinoic acid-inducible gene-I (RIG-I) preferentially recognizes vesicular stomatitis virus (VSV) to trigger signaling cascades that lead to production of interferons and cytokines. However, weak RNA binding capacity of MDA5 significantly attenuates the antiviral response. Here, we reveal that DHX29 as a co-sensor of MDA5 ensures the specific and efficient MDA5-RNA interactions leading to a complete MDA5-mediated antiviral signaling. Depletion of DHX29 substantially reduces the activity of MDA5 whereas activity of RIG-I remains intact. These findings provide a mechanism for DHX29 coactivation of MDA5 and a biological context for MDA5-RNA filaments in antiviral response.
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Affiliation(s)
- Qingyuan Zhu
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
| | - Peng Tan
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, United States of America
| | - Yinyin Li
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
| | - Meng Lin
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
- Key Laboratory of Gene Engineering of the Ministry of Education and State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Chaoran Li
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
- Xiangya Hospital, Central South University, Changsha, China
| | - Jingrong Mao
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
- Xiangya Hospital, Central South University, Changsha, China
| | - Jun Cui
- Key Laboratory of Gene Engineering of the Ministry of Education and State Key Laboratory of Biocontrol, College of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wei Zhao
- Key Laboratory for Stem Cells and Tissue Engineering of the Ministry of Education, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Helen Y. Wang
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
| | - Rong-Fu Wang
- Center for Inflammation and Epigenetics, Houston Methodist Research Institute, Houston, TX, United States of America
- Institute of Biosciences and Technology, College of Medicine, Texas A&M University, Houston, United States of America
- Department of Microbiology and Immunology, Weill Cornell Medicine, Cornell University, New York, NY, United States of America
- * E-mail:
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26
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Identification of host DEAD-box RNA helicases that regulate cellular tropism of oncolytic Myxoma virus in human cancer cells. Sci Rep 2017; 7:15710. [PMID: 29146961 PMCID: PMC5691082 DOI: 10.1038/s41598-017-15941-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 11/06/2017] [Indexed: 12/28/2022] Open
Abstract
Myxoma virus (MYXV), a Leporipoxvirus, is being developed as an oncolytic virotherapeutic for the treatment of a variety of human cancers. MYXV tropism for human cancer cells is largely mediated by intracellular signaling networks that regulate viral replication or innate antiviral response pathways. Thus, MYXV is fully or partially permissive for the majority of human cancer cells that harbor defects in antiviral signaling, but a minority are nonpermissive because the virus infection aborts before its completion. To identify host factors relevant for MYXV tropism in human cancer cells, we performed a small interfering RNA (siRNA) library screen targeting the 58 human DEAD-box RNA helicases in two permissive human cancer cells (HeLa and A549), one semi-permissive (786-0), and one nonpermissive cell line (PANC-1). Five host RNA helicases (DDX3X, DDX5, DHX9, DHX37, DDX52) were inhibitory for optimal replication and thus classified as anti-viral, while three other cellular RNA helicases (DHX29, DHX35, RIG-I) were identified as pro-viral or pro-cellular because knockdown consistently reduced MYXV replication and/or required metabolic functions of permissive cancer cells. These findings suggest that replication of MYXV, and likely all poxviruses, is dramatically regulated positively and negatively by multiple host DEAD-box RNA helicases.
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27
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Heerma van Voss MR, van Diest PJ, Raman V. Targeting RNA helicases in cancer: The translation trap. Biochim Biophys Acta Rev Cancer 2017; 1868:510-520. [PMID: 28965870 DOI: 10.1016/j.bbcan.2017.09.006] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 09/25/2017] [Accepted: 09/26/2017] [Indexed: 12/14/2022]
Abstract
Cancer cells are reliant on the cellular translational machinery for both global elevation of protein synthesis and the translation of specific mRNAs that promote tumor cell survival. Targeting translational control in cancer is therefore increasingly recognized as a promising therapeutic strategy. In this regard, DEAD/H box RNA helicases are a very interesting group of proteins, with several family members regulating mRNA translation in cancer cells. In this review, we delineate the mechanisms by which DEAD/H box proteins modulate oncogenic translation and how inhibition of these RNA helicases can be exploited for anti-cancer therapeutics.
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Affiliation(s)
- Marise R Heerma van Voss
- Department of Radiology and Radiological Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Paul J van Diest
- Department of Radiology and Radiological Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Department of Oncology, Johns Hopkins University, School of Medicine, MD, USA
| | - Venu Raman
- Department of Radiology and Radiological Sciences, Johns Hopkins University, School of Medicine, Baltimore, MD, USA; Department of Pathology, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Oncology, Johns Hopkins University, School of Medicine, MD, USA.
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28
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DHX15 is associated with poor prognosis in acute myeloid leukemia (AML) and regulates cell apoptosis via the NF-kB signaling pathway. Oncotarget 2017; 8:89643-89654. [PMID: 29163777 PMCID: PMC5685698 DOI: 10.18632/oncotarget.20288] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 07/26/2017] [Indexed: 12/25/2022] Open
Abstract
The role of DHX15, a newly identified DEAH-box RNA helicase, in leukemogenesis remains elusive. Here, we identified a recurrent mutation in DHX15 (NM_001358:c.664C>G: p.(R222G)) in one familial AML patient and 4/240 sporadic AML patients. Additionally, DHX15 was commonly overexpressed in AML patients and associated with poor overall survival (OS) (P=0.019) and relapse-free survival (RFS) (P=0.032). In addition, we found a distinct expression pattern of DHX15. DHX15 was highly expressed in hematopoietic stem cells and leukemia cells but was lowly expressed in mature blood cells. DHX15 was down-regulated when AML patients achieved disease remission or when leukemia cell lines were induced to differentiate. DHX15 silencing greatly inhibited leukemia cell proliferation and induced cell apoptosis and G1-phase arrest. In contrast, the restoration of DHX15 expression rescued cell viability and reduced cell apoptosis. In addition, we found that DHX15 was down-regulated when cell apoptosis was induced by ATO (arsenic trioxide); overexpression of DHX15 caused dramatic resistance to ATO-induced cell apoptosis, suggesting an important role for DHX15 in cell apoptosis. We further explored the mechanism of DHX15 in apoptosis and found that overexpression of DHX15 activated NF-kB transcription. Knockdown of DHX15 inhibited the nuclear translocation and activation of the NF-kB subunit P65 in leukemia cells. Several downstream targets of the NF-kB pathway were also down-regulated, and apoptosis-associated genes CASP3 and PARP were activated. In conclusion, this study represents the first demonstration that DHX15 plays an important role in leukemogenesis via the NF-kB signaling pathway and may serve as an independent prognostic marker for AML.
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29
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Martin LJ, Smith SB, Khoutorsky A, Magnussen CA, Samoshkin A, Sorge RE, Cho C, Yosefpour N, Sivaselvachandran S, Tohyama S, Cole T, Khuong TM, Mir E, Gibson DG, Wieskopf JS, Sotocinal SG, Austin JS, Meloto CB, Gitt JH, Gkogkas C, Sonenberg N, Greenspan JD, Fillingim RB, Ohrbach R, Slade GD, Knott C, Dubner R, Nackley AG, Ribeiro-da-Silva A, Neely GG, Maixner W, Zaykin DV, Mogil JS, Diatchenko L. Epiregulin and EGFR interactions are involved in pain processing. J Clin Invest 2017; 127:3353-3366. [PMID: 28783046 DOI: 10.1172/jci87406] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 06/27/2017] [Indexed: 12/27/2022] Open
Abstract
The EGFR belongs to the well-studied ErbB family of receptor tyrosine kinases. EGFR is activated by numerous endogenous ligands that promote cellular growth, proliferation, and tissue regeneration. In the present study, we have demonstrated a role for EGFR and its natural ligand, epiregulin (EREG), in pain processing. We show that inhibition of EGFR with clinically available compounds strongly reduced nocifensive behavior in mouse models of inflammatory and chronic pain. EREG-mediated activation of EGFR enhanced nociception through a mechanism involving the PI3K/AKT/mTOR pathway and matrix metalloproteinase-9. Moreover, EREG application potentiated capsaicin-induced calcium influx in a subset of sensory neurons. Both the EGFR and EREG genes displayed a genetic association with the development of chronic pain in several clinical cohorts of temporomandibular disorder. Thus, EGFR and EREG may be suitable therapeutic targets for persistent pain conditions.
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Affiliation(s)
- Loren J Martin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada.,Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Shad B Smith
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Arkady Khoutorsky
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Claire A Magnussen
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Alexander Samoshkin
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Robert E Sorge
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Chulmin Cho
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Noosha Yosefpour
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | | | - Sarasa Tohyama
- Department of Psychology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Tiffany Cole
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Thang M Khuong
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - Ellen Mir
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dustin G Gibson
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jeffrey S Wieskopf
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Susana G Sotocinal
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Jean Sebastien Austin
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Carolina B Meloto
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Joseph H Gitt
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Christos Gkogkas
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Nahum Sonenberg
- Department of Biochemistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Joel D Greenspan
- Department of Neural and Pain Sciences and Brotman Facial Pain Center, University of Maryland Dental School, Baltimore, Maryland, USA
| | - Roger B Fillingim
- Department of Community Dentistry and Behavioral Science, University of Florida, Gainesville, Florida, USA
| | - Richard Ohrbach
- Department of Oral Diagnostic Services, University at Buffalo, Buffalo, New York, USA
| | - Gary D Slade
- Department of Dental Ecology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Charles Knott
- Battelle Memorial Institute, Durham, North Carolina, USA
| | - Ronald Dubner
- Department of Neural and Pain Sciences and Brotman Facial Pain Center, University of Maryland Dental School, Baltimore, Maryland, USA
| | - Andrea G Nackley
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Alfredo Ribeiro-da-Silva
- Department of Pharmacology and Therapeutics and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - G Gregory Neely
- Charles Perkins Centre and School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia
| | - William Maixner
- Center for Neurosensory Disorders, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dmitri V Zaykin
- National Institutes of Environmental Health Sciences, NIH, Research Triangle Park, North Carolina, USA
| | - Jeffrey S Mogil
- Department of Psychology and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
| | - Luda Diatchenko
- Department of Anesthesia, Faculty of Dentistry and Alan Edwards Centre for Research on Pain, McGill University, Montreal, Quebec, Canada
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30
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Regulation of human immunodeficiency virus type 1 (HIV-1) mRNA translation. Biochem Soc Trans 2017; 45:353-364. [PMID: 28408475 DOI: 10.1042/bst20160357] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 01/06/2017] [Accepted: 01/11/2017] [Indexed: 12/17/2022]
Abstract
Human immunodeficiency virus type 1 (HIV-1) mRNA translation is a complex process that uses the host translation machinery to synthesise viral proteins. Several mechanisms for HIV-1 mRNA translation initiation have been proposed including (1) cap-dependent, eIF4E-dependent, (2) cap-dependent, cap-binding complex-dependent, (3) internal ribosome entry sites, and (4) ribosome shunting. While these mechanisms promote HIV-1 mRNA translation in the context of in vitro systems and subgenomic constructs, there are substantial knowledge gaps in understanding how they regulate viral protein production in the context of full-length virus infection. In this review, we will summarise the different translation mechanisms used by HIV-1 mRNAs and the challenges in understanding how they regulate protein synthesis during viral infection.
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31
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Pisareva VP, Pisarev AV. DHX29 and eIF3 cooperate in ribosomal scanning on structured mRNAs during translation initiation. RNA (NEW YORK, N.Y.) 2016; 22:1859-1870. [PMID: 27733651 PMCID: PMC5113206 DOI: 10.1261/rna.057851.116] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/12/2016] [Indexed: 06/06/2023]
Abstract
Eukaryotic translation initiation is a complex process involving many components. eIF3 is a scaffold for multiple initiation factors and plays multiple roles in initiation, and DHX29 helicase enhances the formation of the 48S initiation complex on structured mRNAs. Because DHX29 is not a processive helicase, the mechanism underlying its activity is unclear. Here, we show that DHX29 establishes many points of contact with eIF3. In particular, the unique N terminus of DHX29 associates with the RNA recognition motif of eIF3b and the C terminus of the eIF3a subunits of eIF3, and the disruption of either contact impairs DHX29 activity. In turn, DHX29 has weak points of contact with mRNA in the 48S initiation complex, and the pathway taken by mRNA remains unchanged. These results exclude the direct role for this protein in unwinding. Thus, DHX29 and eIF3 cooperate in scanning on structured mRNAs. Our findings support previous genetic data on the role of eIF3 during scanning.
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Affiliation(s)
- Vera P Pisareva
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA
| | - Andrey V Pisarev
- Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, New York 11203, USA
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DHX33 Transcriptionally Controls Genes Involved in the Cell Cycle. Mol Cell Biol 2016; 36:2903-2917. [PMID: 27601587 DOI: 10.1128/mcb.00314-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 08/30/2016] [Indexed: 02/08/2023] Open
Abstract
The RNA helicase DHX33 has been shown to be a critical regulator of cell proliferation and growth. However, the underlying mechanisms behind DHX33 function remain incompletely understood. We present original evidence in multiple cell lines that DHX33 transcriptionally controls the expression of genes involved in the cell cycle, notably cyclin, E2F1, cell division cycle (CDC), and minichromosome maintenance (MCM) genes. DHX33 physically associates with the promoters of these genes and controls the loading of active RNA polymerase II onto these promoters. DHX33 deficiency abrogates cell cycle progression and DNA replication and leads to cell apoptosis. In zebrafish, CRISPR-mediated knockout of DHX33 results in downregulation of cyclin A2, cyclin B2, cyclin D1, cyclin E2, cdc6, cdc20, E2F1, and MCM complexes in DHX33 knockout embryos. Additionally, we found the overexpression of DHX33 in a subset of non-small-cell lung cancers and in Ras-mutated human lung cancer cell lines. Forced reduction of DHX33 in these cancer cells abolished tumor formation in vivo Our study demonstrates for the first time that DHX33 acts as a direct transcriptional regulator to promote cell cycle progression and plays an important role in driving cell proliferation during both embryo development and tumorigenesis.
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33
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Attar-Schneider O, Drucker L, Gottfried M. Migration and epithelial-to-mesenchymal transition of lung cancer can be targeted via translation initiation factors eIF4E and eIF4GI. J Transl Med 2016; 96:1004-15. [PMID: 27501049 DOI: 10.1038/labinvest.2016.77] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/18/2016] [Accepted: 06/20/2016] [Indexed: 02/06/2023] Open
Abstract
Metastasis underlies cancer morbidity and accounts for disease progression and significant death rates generally and in non-small cell lung cancer (NSCLC) particularly. Therefore, it is critically important to understand the molecular events that regulate metastasis. Accumulating data portray a central role for protein synthesis, particularly translation initiation (TI) factors eIF4E and eIF4G in tumorigenesis and patients' survival. We have published that eIF4E/eIF4GI activities and consequently NSCLC cell migration are modulated by bone-marrow mesenchymal stem cell secretomes, suggesting a role for TI in metastasis. Here, we aimed to expand our understanding of the TI factors significance to NSCLC characteristics, particularly epithelial-to-mesenchymal transition (EMT) and migration, supportive of metastasis. In a model of NSCLC cell lines (H1299, H460), we inhibited eIF4E/eIF4GI's expressions (siRNA, ribavirin) and assessed NSCLC cell lines' migration (scratch), differentiation (EMT, immunoblotting), and expression of select microRNAs (qPCR). Initially, we determined an overexpression of several TI factors (eIF4E, eIF4GI, eIF4B, and DHX29) and their respective targets in NSCLC compared with normal lung samples (70-350%↑, P<0.05). Knockdown (KD) of eIF4E/eIF4GI in NSCLC cell lines (70%↓, P<0.05) also manifested in decreased target levels (ERα, SMAD5, NFkB, CyclinD1, c-MYC, and HIF1α) (20-50%↓, P<0.05). eIF4E/eIF4GI KD also attenuated cell migration (60-75%↓, P<0.05), EMT promoters (15-90%↓, P<0.05), and enhanced EMT suppressors (30-380%↑, P<0.05). The importance of eIF4E KD to NSCLC phenotype was further corroborated with its inhibitor, ribavirin. Changes in expression of essential microRNAs implicated in NSCLC cell migration concluded the study (20-100%, P<0.05). In summary, targeting eIF4E/eIF4GI reduces migration and EMT, both essential for metastasis, thereby underscoring the potential of TI targeting in NSCLC therapy, especially the already clinically employed agents (ribavirin/4EGI). Comparison of these findings with previously reported effects of eIF4E/eIF4GI KD in multiple myeloma suggests a collective role for these TI factors in cancer progression.
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Affiliation(s)
- Oshrat Attar-Schneider
- Lung Cancer Research Laboratory, Lung Cancer Unit, Meir Medical Center, Kfar Saba, Israel.,Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Liat Drucker
- Oncogenetic Laboratory, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Maya Gottfried
- Lung Cancer Research Laboratory, Lung Cancer Unit, Meir Medical Center, Kfar Saba, Israel.,Oncology Department, Lung Cancer Unit, Meir Medical Center, Kfar Saba, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
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Curran JA, Weiss B. What Is the Impact of mRNA 5' TL Heterogeneity on Translational Start Site Selection and the Mammalian Cellular Phenotype? Front Genet 2016; 7:156. [PMID: 27630668 PMCID: PMC5005323 DOI: 10.3389/fgene.2016.00156] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 08/16/2016] [Indexed: 12/23/2022] Open
Abstract
A major determinant in the efficiency of ribosome loading onto mRNAs is the 5′ TL (transcript leader or 5′ UTR). In addition, elements within this region also impact on start site selection demonstrating that it can modulate the protein readout at both quantitative and qualitative levels. With the increasing wealth of data generated by the mining of the mammalian transcriptome, it has become evident that a genes 5′ TL is not homogeneous but actually exhibits significant heterogeneity. This arises due to the utilization of alternative promoters, and is further compounded by significant variability with regards to the precise transcriptional start sites of each (not to mention alternative splicing). Consequently, the transcript for a protein coding gene is not a unique mRNA, but in-fact a complexed quasi-species of variants whose composition may respond to the changing physiological environment of the cell. Here we examine the potential impact of these events with regards to the protein readout.
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Affiliation(s)
- Joseph A Curran
- Department of Microbiology and Molecular Medicine, Medical School, University of GenevaGeneva, Switzerland; Institute of Genetics and Genomics of Geneva, University of GenevaGeneva, Switzerland
| | - Benjamin Weiss
- Department of Microbiology and Molecular Medicine, Medical School, University of Geneva Geneva, Switzerland
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35
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Mitotic MELK-eIF4B signaling controls protein synthesis and tumor cell survival. Proc Natl Acad Sci U S A 2016; 113:9810-5. [PMID: 27528663 DOI: 10.1073/pnas.1606862113] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The protein kinase maternal and embryonic leucine zipper kinase (MELK) is critical for mitotic progression of cancer cells; however, its mechanisms of action remain largely unknown. By combined approaches of immunoprecipitation/mass spectrometry and peptide library profiling, we identified the eukaryotic translation initiation factor 4B (eIF4B) as a MELK-interacting protein during mitosis and a bona fide substrate of MELK. MELK phosphorylates eIF4B at Ser406, a modification found to be most robust in the mitotic phase of the cell cycle. We further show that the MELK-eIF4B signaling axis regulates protein synthesis during mitosis. Specifically, synthesis of myeloid cell leukemia 1 (MCL1), an antiapoptotic protein known to play a role in cancer cell survival during cell division, depends on the function of MELK-elF4B. Inactivation of MELK or eIF4B results in reduced protein synthesis of MCL1, which, in turn, induces apoptotic cell death of cancer cells. Our study thus defines a MELK-eIF4B signaling axis that regulates protein synthesis during mitosis, and consequently influences cancer cell survival.
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Abstract
Synthesis of polypeptides from mRNA (translation) is a fundamental cellular process that is coordinated and catalyzed by a set of canonical ‘translation factors’. Surprisingly, the translation factors of Drosophila melanogaster have not yet been systematically identified, leading to inconsistencies in their nomenclature and shortcomings in functional (Gene Ontology, GO) annotations. Here, we describe the complete set of translation factors in D. melanogaster, applying nomenclature already in widespread use in other species, and revising their functional annotation. The collection comprises 43 initiation factors, 12 elongation factors, 3 release factors and 6 recycling factors, totaling 64 of which 55 are cytoplasmic and 9 are mitochondrial. We also provide an overview of notable findings and particular insights derived from Drosophila about these factors. This catalog, together with the incorporation of the improved nomenclature and GO annotation into FlyBase, will greatly facilitate access to information about the functional roles of these important proteins.
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Affiliation(s)
- Steven J Marygold
- a FlyBase, Department of Physiology , Development and Neuroscience, University of Cambridge , Cambridge , UK
| | - Helen Attrill
- a FlyBase, Department of Physiology , Development and Neuroscience, University of Cambridge , Cambridge , UK
| | - Paul Lasko
- b Department of Biology , McGill University , Bellini Life Sciences Complex, Montreal, Quebec , Canada
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Simonetti A, Brito Querido J, Myasnikov AG, Mancera-Martinez E, Renaud A, Kuhn L, Hashem Y. eIF3 Peripheral Subunits Rearrangement after mRNA Binding and Start-Codon Recognition. Mol Cell 2016; 63:206-217. [PMID: 27373335 DOI: 10.1016/j.molcel.2016.05.033] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 04/07/2016] [Accepted: 05/23/2016] [Indexed: 11/30/2022]
Abstract
mRNA translation initiation in eukaryotes requires the cooperation of a dozen eukaryotic initiation factors (eIFs) forming several complexes, which leads to mRNA attachment to the small ribosomal 40S subunit, mRNA scanning for start codon, and accommodation of initiator tRNA at the 40S P site. eIF3, composed of 13 subunits, 8 core (a, c, e, f, h, l, k, and m) and 5 peripheral (b, d, g, i, and j), plays a central role during this process. Here we report a cryo-electron microscopy structure of a mammalian 48S initiation complex at 5.8 Å resolution. It shows the relocation of subunits eIF3i and eIF3g to the 40S intersubunit face on the GTPase binding site, at a late stage in initiation. On the basis of a previous study, we demonstrate the relocation of eIF3b to the 40S intersubunit face, binding below the eIF2-Met-tRNAi(Met) ternary complex upon mRNA attachment. Our analysis reveals the deep rearrangement of eIF3 and unravels the molecular mechanism underlying eIF3 function in mRNA scanning and timing of ribosomal subunit joining.
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Affiliation(s)
- Angelita Simonetti
- CNRS, Architecture et Réactivité de l'ARN UPR9002, Université de Strasbourg, 67084 Strasbourg, France.
| | - Jailson Brito Querido
- CNRS, Architecture et Réactivité de l'ARN UPR9002, Université de Strasbourg, 67084 Strasbourg, France
| | | | - Eder Mancera-Martinez
- CNRS, Architecture et Réactivité de l'ARN UPR9002, Université de Strasbourg, 67084 Strasbourg, France
| | - Adeline Renaud
- CNRS, Architecture et Réactivité de l'ARN UPR9002, Université de Strasbourg, 67084 Strasbourg, France
| | - Lauriane Kuhn
- CNRS, Proteomic Platform Strasbourg - Esplanade, 67084 Strasbourg, France
| | - Yaser Hashem
- CNRS, Architecture et Réactivité de l'ARN UPR9002, Université de Strasbourg, 67084 Strasbourg, France.
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The molecular choreography of protein synthesis: translational control, regulation, and pathways. Q Rev Biophys 2016; 49:e11. [PMID: 27658712 DOI: 10.1017/s0033583516000056] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Translation of proteins by the ribosome regulates gene expression, with recent results underscoring the importance of translational control. Misregulation of translation underlies many diseases, including cancer and many genetic diseases. Decades of biochemical and structural studies have delineated many of the mechanistic details in prokaryotic translation, and sketched the outlines of eukaryotic translation. However, translation may not proceed linearly through a single mechanistic pathway, but likely involves multiple pathways and branchpoints. The stochastic nature of biological processes would allow different pathways to occur during translation that are biased by the interaction of the ribosome with other translation factors, with many of the steps kinetically controlled. These multiple pathways and branchpoints are potential regulatory nexus, allowing gene expression to be tuned at the translational level. As research focus shifts toward eukaryotic translation, certain themes will be echoed from studies on prokaryotic translation. This review provides a general overview of the dynamic data related to prokaryotic and eukaryotic translation, in particular recent findings with single-molecule methods, complemented by biochemical, kinetic, and structural findings. We will underscore the importance of viewing the process through the viewpoints of regulation, translational control, and heterogeneous pathways.
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The multiple functions of RNA helicases as drivers and regulators of gene expression. Nat Rev Mol Cell Biol 2016; 17:426-38. [PMID: 27251421 DOI: 10.1038/nrm.2016.50] [Citation(s) in RCA: 178] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
RNA helicases comprise the largest family of enzymes involved in the metabolism of mRNAs, the processing and fate of which rely on their packaging into messenger ribonucleoprotein particles (mRNPs). In this Review, we describe how the capacity of some RNA helicases to either remodel or lock the composition of mRNP complexes underlies their pleiotropic functions at different steps of the gene expression process. We illustrate the roles of RNA helicases in coordinating gene expression steps and programmes, and propose that RNA helicases function as molecular drivers and guides of the progression of their mRNA substrates from one RNA-processing factory to another, to a productive mRNA pool that leads to protein synthesis or to unproductive mRNA pools that are stored or degraded.
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40
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Tanabe A, Tanikawa K, Tsunetomi M, Takai K, Ikeda H, Konno J, Torigoe T, Maeda H, Kutomi G, Okita K, Mori M, Sahara H. RNA helicase YTHDC2 promotes cancer metastasis via the enhancement of the efficiency by which HIF-1α mRNA is translated. Cancer Lett 2016; 376:34-42. [DOI: 10.1016/j.canlet.2016.02.022] [Citation(s) in RCA: 153] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 02/09/2016] [Accepted: 02/11/2016] [Indexed: 02/05/2023]
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41
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Tian QH, Zhang MF, Luo RG, Fu J, He C, Hu G, Zeng JS. DHX33 expression is increased in hepatocellular carcinoma and indicates poor prognosis. Biochem Biophys Res Commun 2016; 473:1163-1169. [DOI: 10.1016/j.bbrc.2016.04.033] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 04/08/2016] [Indexed: 01/22/2023]
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Vincent HA, Ziehr B, Moorman NJ. Human Cytomegalovirus Strategies to Maintain and Promote mRNA Translation. Viruses 2016; 8:97. [PMID: 27089357 PMCID: PMC4848592 DOI: 10.3390/v8040097] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Revised: 03/25/2016] [Accepted: 03/31/2016] [Indexed: 02/02/2023] Open
Abstract
mRNA translation requires the ordered assembly of translation initiation factors and ribosomal subunits on a transcript. Host signaling pathways regulate each step in this process to match levels of protein synthesis to environmental cues. In response to infection, cells activate multiple defenses that limit viral protein synthesis, which viruses must counteract to successfully replicate. Human cytomegalovirus (HCMV) inhibits host defenses that limit viral protein expression and manipulates host signaling pathways to promote the expression of both host and viral proteins necessary for virus replication. Here we review key regulatory steps in mRNA translation, and the strategies used by HCMV to maintain protein synthesis in infected cells.
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Affiliation(s)
- Heather A Vincent
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Benjamin Ziehr
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Nathaniel J Moorman
- Department of Microbiology & Immunology, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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Pisareva VP, Pisarev AV. DHX29 reduces leaky scanning through an upstream AUG codon regardless of its nucleotide context. Nucleic Acids Res 2016; 44:4252-65. [PMID: 27067542 PMCID: PMC4872109 DOI: 10.1093/nar/gkw240] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 03/29/2016] [Indexed: 11/23/2022] Open
Abstract
During eukaryotic translation initiation, the 43S preinitiation complex (43S PIC), consisting of the 40S ribosomal subunit, eukaryotic initiation factors (eIFs) and initiator tRNA scans mRNA to find an appropriate start codon. Key roles in the accuracy of initiation codon selection belong to eIF1 and eIF1A, whereas the mammalian-specific DHX29 helicase substantially contributes to ribosomal scanning of structured mRNAs. Here, we show that DHX29 stimulates the recognition of the AUG codon but not the near-cognate CUG codon regardless of its nucleotide context during ribosomal scanning. The stimulatory effect depends on the contact between DHX29 and eIF1A. The unique DHX29 N-terminal domain binds to the ribosomal site near the mRNA entrance, where it contacts the eIF1A OB domain. UV crosslinking assays revealed that DHX29 may rearrange eIF1A and eIF2α in key nucleotide context positions of ribosomal complexes. Interestingly, DHX29 impedes the 48S initiation complex formation in the absence of eIF1A perhaps due to forming a physical barrier that prevents the 43S PIC from loading onto mRNA. Mutational analysis allowed us to split the mRNA unwinding and codon selection activities of DHX29. Thus, DHX29 is another example of an initiation factor contributing to start codon selection.
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Affiliation(s)
- Vera P Pisareva
- Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA
| | - Andrey V Pisarev
- Department of Cell Biology, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203, USA
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44
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Lee T, Paquet M, Larsson O, Pelletier J. Tumor cell survival dependence on the DHX9 DExH-box helicase. Oncogene 2016; 35:5093-105. [PMID: 26973242 PMCID: PMC5023453 DOI: 10.1038/onc.2016.52] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 01/13/2016] [Accepted: 02/01/2016] [Indexed: 12/23/2022]
Abstract
The ATP-dependent DExH/D-box helicase DHX9 is a key participant in a number of gene regulatory steps, including transcriptional, translational, microRNA-mediated control, DNA replication, and maintenance of genomic stability. DHX9 has also been implicated in tumor cell maintenance and drug response. Here, we report that inhibition of DHX9 expression is lethal to human cancer cell lines and murine Eµ−Myc lymphomas. Using a novel conditional shDHX9 mouse model, we demonstrate that sustained and prolonged (6 months) suppression of DHX9 does not result in any deleterious effects at the organismal level. Body weight, blood biochemistry, and histology of various tissues were comparable to control mice. Global gene expression profiling revealed that although reduction of DHX9 expression resulted in multiple transcriptome changes, these were relatively benign and did not lead to any discernible phenotype. Our results demonstrate a robust tolerance for systemic DHX9 suppression in vivo and support the targeting of DHX9 as an effective and specific chemotherapeutic approach.
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Affiliation(s)
- T Lee
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - M Paquet
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, Québec
| | - O Larsson
- Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden
| | - J Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada.,Department of Oncology, McGill University, Montreal, Quebec, Canada.,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
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45
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Lee SW, Wu LSH, Huang GM, Huang KY, Lee TY, Weng JTY. Gene expression profiling identifies candidate biomarkers for active and latent tuberculosis. BMC Bioinformatics 2016; 17 Suppl 1:3. [PMID: 26818387 PMCID: PMC4895247 DOI: 10.1186/s12859-015-0848-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND Tuberculosis (TB) is a serious infectious disease in that 90% of those latently infected with Mycobacterium tuberculosis present no symptoms, but possess a 10% lifetime chance of developing active TB. To prevent the spread of the disease, early diagnosis is crucial. However, current methods of detection require improvement in sensitivity, efficiency or specificity. In the present study, we conducted a microarray experiment, comparing the gene expression profiles in the peripheral blood mononuclear cells among individuals with active TB, latent infection, and healthy conditions in a Taiwanese population. RESULTS Bioinformatics analysis revealed that most of the differentially expressed genes belonged to immune responses, inflammation pathways, and cell cycle control. Subsequent RT-PCR validation identified four differentially expressed genes, NEMF, ASUN, DHX29, and PTPRC, as potential biomarkers for the detection of active and latent TB infections. Receiver operating characteristic analysis showed that the expression level of PTPRC may discriminate active TB patients from healthy individuals, while ASUN could differentiate between the latent state of TB infection and healthy condidtion. In contrast, DHX29 may be used to identify latently infected individuals among active TB patients or healthy individuals. To test the concept of using these biomarkers as diagnostic support, we constructed classification models using these candidate biomarkers and found the Naïve Bayes-based model built with ASUN, DHX29, and PTPRC to yield the best performance. CONCLUSIONS Our study demonstrated that gene expression profiles in the blood can be used to identify not only active TB patients, but also to differentiate latently infected patients from their healthy counterparts. Validation of the constructed computational model in a larger sample size would confirm the reliability of the biomarkers and facilitate the development of a cost-effective and sensitive molecular diagnostic platform for TB.
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Affiliation(s)
- Shih-Wei Lee
- Taoyuan General Hospital, Ministry of Health and Welfare, Taoyuan, Taiwan. .,Department of Life Sciences, National Central University, Taoyuan, Taiwan.
| | | | - Guan-Mau Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan.
| | - Kai-Yao Huang
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan.
| | - Tzong-Yi Lee
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan. .,Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan.
| | - Julia Tzu-Ya Weng
- Department of Computer Science and Engineering, Yuan Ze University, Taoyuan, Taiwan. .,Innovation Center for Big Data and Digital Convergence, Yuan Ze University, Taoyuan, Taiwan.
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He Y, Andersen GR, Nielsen KH. The function and architecture of DEAH/RHA helicases. Biomol Concepts 2015; 2:315-26. [PMID: 25962039 DOI: 10.1515/bmc.2011.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 05/24/2011] [Indexed: 12/11/2022] Open
Abstract
Helicases are ubiquitous enzymes that participate in every aspect of nucleic acid metabolism. The DEAH/RHA family of helicases are involved in a variety of cellular processes including transcriptional and translational regulation, pre-mRNA splicing, pre-rRNA processing, mRNA export and decay, in addition to the innate immune response. Recently, the first crystal structures of a DEAH/RHA helicase unveiled the unique structural features of this helicase family. These structures furthermore illuminate the molecular mechanism of these proteins and provide a framework for analysis of their interaction with nucleic acids, regulatory proteins and large macromolecular complexes.
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Tsukamoto Y, Fumoto S, Noguchi T, Yanagihara K, Hirashita Y, Nakada C, Hijiya N, Uchida T, Matsuura K, Hamanaka R, Murakami K, Seto M, Inomata M, Moriyama M. Expression of DDX27 contributes to colony-forming ability of gastric cancer cells and correlates with poor prognosis in gastric cancer. Am J Cancer Res 2015; 5:2998-3014. [PMID: 26693055 PMCID: PMC4656726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/28/2015] [Indexed: 06/05/2023] Open
Abstract
Previously, we have reported that gain at chromosome 20q13 is the most common genomic copy number aberration in gastric cancer (GC) (29/30 cases), and that among the genes located in this region, we have identified DDX27, whose expression level shows the highest correlation with genomic copy number, as a candidate therapeutic target for GC. Here, we analyzed the clinicopathological significance of DDX27 using immunohistochemistry and studied its functions using knockdown assays. We found that DDX27 was frequently upregulated in GC tissues (98 of 140 cases, 70%), and significantly associated with venous invasion and liver metastasis. Furthermore, multivariate analysis of GC patients showed that high expression of DDX27 was independently associated with poorer prognosis. In functional assays, knockdown of DDX27 reduced the ability of GC cells to form colonies both on conventional plates and soft agar, but had little effect on their invasiveness. We also found that knockdown of DDX27 reduced the viability of GC cells through inhibition of cell cycle progression independently of apoptosis. Interestingly, DDX27 depletion induced accumulation of TP53 in a TP53 wild-type cell line, AGS, but not in a TP53-deleted cell line, 44As3, although DDX27 knockdown commonly reduced the viability of both, indicating the TP53-dependent and independent cell cycle control of DDX27. Thus, our results suggest that expression of DDX27 contributes to colony formation by GC cells through cell cycle control and may be a potential therapeutic target for GC patients with chromosome gain at 20q13.
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Affiliation(s)
- Yoshiyuki Tsukamoto
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Shoichi Fumoto
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
- Department of Gastroenterological and Pediatric Surgery, Faculty of Medicine, Oita UniversityOita, Japan
| | - Tsuyoshi Noguchi
- Center for Community Medicine, Division of Surgery, Faculty of Medicine, Oita UniversityOita, Japan
| | - Kazuyoshi Yanagihara
- Division of Pathology, Exploratory Oncology Research & Clinical Trial Center, National Cancer CenterChiba, Japan
| | - Yuka Hirashita
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
- Department of Gastroenterology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Chisato Nakada
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Naoki Hijiya
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Tomohisa Uchida
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Keiko Matsuura
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Ryoji Hamanaka
- Department of Cell Biology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Kazunari Murakami
- Department of Gastroenterology, Faculty of Medicine, Oita UniversityOita, Japan
| | - Masao Seto
- Department of Pathology, Kurume University School of MedicineFukuoka, Japan
| | - Masafumi Inomata
- Department of Gastroenterological and Pediatric Surgery, Faculty of Medicine, Oita UniversityOita, Japan
| | - Masatsugu Moriyama
- Department of Molecular Pathology, Faculty of Medicine, Oita UniversityOita, Japan
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Rojas-Araya B, Ohlmann T, Soto-Rifo R. Translational Control of the HIV Unspliced Genomic RNA. Viruses 2015; 7:4326-51. [PMID: 26247956 PMCID: PMC4576183 DOI: 10.3390/v7082822] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 05/18/2015] [Accepted: 07/17/2015] [Indexed: 01/16/2023] Open
Abstract
Post-transcriptional control in both HIV-1 and HIV-2 is a highly regulated process that commences in the nucleus of the host infected cell and finishes by the expression of viral proteins in the cytoplasm. Expression of the unspliced genomic RNA is particularly controlled at the level of RNA splicing, export, and translation. It appears increasingly obvious that all these steps are interconnected and they result in the building of a viral ribonucleoprotein complex (RNP) that must be efficiently translated in the cytosolic compartment. This review summarizes our knowledge about the genesis, localization, and expression of this viral RNP.
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Affiliation(s)
- Bárbara Rojas-Araya
- Molecular and Cellular Virology Laboratory, Program of Virology, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Independencia 834100, Santiago, Chile.
| | - Théophile Ohlmann
- CIRI, International Center for Infectiology Research, Université de Lyon, Lyon 69007, France.
- Inserm, U1111, Lyon 69007, France.
- Ecole Normale Supérieure de Lyon, Lyon 69007, France.
- Université Lyon 1, Centre International de Recherche en Infectiologie, Lyon 69007, France.
- CNRS, UMR5308, Lyon 69007, France.
| | - Ricardo Soto-Rifo
- Molecular and Cellular Virology Laboratory, Program of Virology, Institute of Biomedical Sciences, Faculty of Medicine, University of Chile, Independencia 834100, Santiago, Chile.
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Tsai BP, Jimenez J, Lim S, Fitzgerald KD, Zhang M, Chuah CTH, Axelrod H, Wilson L, Ong ST, Semler BL, Waterman ML. A novel Bcr-Abl-mTOR-eIF4A axis regulates IRES-mediated translation of LEF-1. Open Biol 2015; 4:140180. [PMID: 25392452 PMCID: PMC4248067 DOI: 10.1098/rsob.140180] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Internal ribosome entry sites (IRESs) in cellular mRNAs direct expression of growth-promoting factors through an alternative translation mechanism that has yet to be fully defined. Lymphoid enhancer factor-1 (LEF-1), a Wnt-mediating transcription factor important for cell survival and metastasis in cancer, is produced via IRES-directed translation, and its mRNA is frequently upregulated in malignancies, including chronic myeloid leukaemia (CML). In this study, we determined that LEF1 expression is regulated by Bcr-Abl, the oncogenic protein that drives haematopoietic cell transformation to CML. We have previously shown that the LEF1 5′ untranslated region recruits a complex of proteins to its IRES, including the translation initiation factor eIF4A. In this report, we use two small molecule inhibitors, PP242 (dual mTOR (mammalian target of rapamycin) kinase inhibitor) and hippuristanol (eIF4A inhibitor), to define IRES regulation via a Bcr-Abl–mTOR–eIF4A axis in CML cell lines and primary patient leukaemias. We found that LEF1 and other IRESs are uniquely sensitive to the activities of Bcr-Abl/mTOR. Most notably, we discovered that eIF4A, an RNA helicase, elicits potent non-canonical effects on the LEF1 IRES. Hippuristanol inhibition of eIF4A stalls translation of IRES mRNA and triggers dissociation from polyribosomes. We propose that a combination drug strategy which targets mTOR and IRES-driven translation disrupts key factors that contribute to growth and proliferation in CML.
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Affiliation(s)
- Becky Pinjou Tsai
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Judith Jimenez
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Sharon Lim
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore
| | - Kerry D Fitzgerald
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Min Zhang
- Division of Hematology/Oncology, Department of Medicine, School of Medicine, University of California, Irvine, CA, USA
| | - Charles T H Chuah
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore
| | - Haley Axelrod
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Luke Wilson
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - S Tiong Ong
- Cancer and Stem Cell Biology Signature Research Program, Duke-NUS Graduate Medical School, Singapore Department of Haematology, Singapore General Hospital, Singapore Department of Medical Oncology, National Cancer Centre, Singapore Department of Medicine, Duke University Medical Center, Durham, NC, USA
| | - Bert L Semler
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
| | - Marian L Waterman
- Department of Microbiology and Molecular Genetics, School of Medicine, University of California, Irvine, CA, USA
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Sen ND, Zhou F, Ingolia NT, Hinnebusch AG. Genome-wide analysis of translational efficiency reveals distinct but overlapping functions of yeast DEAD-box RNA helicases Ded1 and eIF4A. Genome Res 2015; 25:1196-205. [PMID: 26122911 PMCID: PMC4510003 DOI: 10.1101/gr.191601.115] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/20/2015] [Indexed: 12/28/2022]
Abstract
DEAD-box RNA helicases eIF4A and Ded1 are believed to promote translation initiation by resolving mRNA secondary structures that impede ribosome attachment at the mRNA 5′ end or subsequent scanning of the 5′ UTR, but whether they perform unique or overlapping functions in vivo is poorly understood. We compared the effects of mutations in Ded1 or eIF4A on global translational efficiencies (TEs) in budding yeast Saccharomyces cerevisiae by ribosome footprint profiling. Despite similar reductions in bulk translation, inactivation of a cold-sensitive Ded1 mutant substantially reduced the TEs of >600 mRNAs, whereas inactivation of a temperature-sensitive eIF4A variant encoded by tif1-A79V (in a strain lacking the ortholog TIF2) yielded <40 similarly impaired mRNAs. The broader requirement for Ded1 did not reflect more pervasive secondary structures at low temperature, as inactivation of temperature-sensitive and cold-sensitive ded1 mutants gave highly correlated results. Interestingly, Ded1-dependent mRNAs exhibit greater than average 5′ UTR length and propensity for secondary structure, implicating Ded1 in scanning through structured 5′ UTRs. Reporter assays confirmed that cap-distal stem–loop insertions increase dependence on Ded1 but not eIF4A for efficient translation. While only a small fraction of mRNAs shows a heightened requirement for eIF4A, dependence on eIF4A is correlated with requirements for Ded1 and 5′ UTR features characteristic of Ded1-dependent mRNAs. Our findings suggest that Ded1 is critically required to promote scanning through secondary structures within 5′ UTRs, and while eIF4A cooperates with Ded1 in this function, it also promotes a step of initiation common to virtually all yeast mRNAs.
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Affiliation(s)
- Neelam Dabas Sen
- Laboratory of Gene Regulation and Development, Eunice K. Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Fujun Zhou
- Laboratory of Gene Regulation and Development, Eunice K. Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Nicholas T Ingolia
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
| | - Alan G Hinnebusch
- Laboratory of Gene Regulation and Development, Eunice K. Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
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