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Wagner PA, Song M, Ficner R, Kuhle B, Marintchev A. Molecular basis for the interactions of eIF2β with eIF5, eIF2B, and 5MP1 and their regulation by CK2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.25.591181. [PMID: 38712236 PMCID: PMC11071521 DOI: 10.1101/2024.04.25.591181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The heterotrimeric GTPase eukaryotic translation initiation factor 2 (eIF2) delivers the initiator Met-tRNAi to the ribosomal translation preinitiation complex. eIF2β has three lysine-rich repeats (K-boxes) in its N-terminal tail, which are important for binding to the GTPase-activating protein (GAP) eIF5, the guanine nucleotide exchange factor (GEF) eIF2B, and the regulator eIF5-mimic protein (5MP). Here, we combine X-ray crystallography with NMR to understand the molecular basis and dynamics of these interactions. The crystal structure of yeast eIF5-CTD in complex with K-box 3 of eIF2β reveals an extended binding site on eIF2β, far beyond the K-box. We show that human eIF5, eIF2Bε, and 5MP1 can all bind to each of the three K-boxes, while reducing each other's affinities. Moreover, all these affinities are increased by CK2 phosphomimetic mutations. Our results reveal how eIF5, eIF2B, and 5MP displace each other from eIF2, and elucidate the role of CK2 in remodeling the translation apparatus.
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Jin K, Li Y, Wei R, Liu Y, Wang S, Tian H. BZW2 promotes malignant progression in lung adenocarcinoma through enhancing the ubiquitination and degradation of GSK3β. Cell Death Discov 2024; 10:105. [PMID: 38424042 PMCID: PMC10904796 DOI: 10.1038/s41420-024-01879-7] [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: 11/14/2023] [Revised: 02/20/2024] [Accepted: 02/21/2024] [Indexed: 03/02/2024] Open
Abstract
The role of Basic leucine zipper and W2 domains 2 (BZW2) in the advancement of different types of tumors is noteworthy, but its involvement and molecular mechanisms in lung adenocarcinoma (LUAD) remain uncertain. Through this investigation, it was found that the upregulation of BZW2 was observed in LUAD tissues, which was associated with an unfavorable prognosis for individuals diagnosed with LUAD, as indicated by data from Gene Expression Omnibus and The Cancer Genome Atlas databases. Based on the clinicopathologic characteristics of LUAD patients from the tissue microarray, both univariate and multivariate analyses indicated that BZW2 functioned as an independent prognostic factor for LUAD. In terms of mechanism, BZW2 interacted with glycogen synthase kinase-3 beta (GSK3β) and enhanced the ubiquitination-mediated degradation of GSK3β through slowing down of the dissociation of the ubiquitin ligase complex, which consists of GSK3β and TNF receptor-associated factor 6. Moreover, BZW2 stimulated Wnt/β-catenin signaling pathway through GSK3β, thereby facilitating the advancement of LUAD. In conclusion, BZW2 was a significant promoter of LUAD. The research we conducted identified a promising diagnostic and therapeutic target for LUAD.
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Affiliation(s)
- Kai Jin
- Department of Thoracic Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Yongmeng Li
- Department of Thoracic Surgery, the First Affiliated Hospital of Shandong First Medical University & Shandong Provincial Qianfoshan Hospital, Jinan, Shandong, China
| | - Ruyuan Wei
- Department of Cardiovascular Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Yanfei Liu
- Department of Anesthesiology, Qilu Children's Hospital of Shandong University, Jinan, China
| | - Shuai Wang
- Department of Thoracic Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China
| | - Hui Tian
- Department of Thoracic Surgery, Qilu Hospital of Shandong University, Jinan, Shandong, China.
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3
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Long X, Wen F, Li J, Huang X. LncRNA FEZF1-AS1 accelerates multiple myeloma progression by regulating IGF2BP1/BZW2 signaling. Hematol Oncol 2023; 41:694-703. [PMID: 37125488 DOI: 10.1002/hon.3157] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 03/16/2023] [Accepted: 04/08/2023] [Indexed: 05/02/2023]
Abstract
Multiple myeloma (MM) is the second largest hematological tumor with clonal proliferation of malignant plasma cells. Growing reports have revealed that the dysregulation of long non-coding RNA (lncRNA) is involved in the MM progression. Nevertheless, lncRNA FEZF1 antisense RNA 1 (FEZF1-AS1) remain not deeply explored. The RNA transcripts and protein level of MM-associated molecule were measured by quantitative real-time polymerase chain reaction or western blot assays, respectively. The clinical correlation was analyzed by Pearson analysis. Molecular interactions among lncRNA FEZF1-AS1, basic leucine zipper and W2 domain 2 (BZW2) and insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) were verified by RNA immunoprecipitation and RNA pull-down assays. The survival of MM cells was detected by cell counting kit-8 and flow cytometry assays. Xenograft tumor in vivo was performed to assess tumor growth. The RNA transcripts of lncRNA FEZF1-AS1, BZW2 and IGF2BP1 were upregulated in MM samples compared to those in healthy donors. Knockdown of lncRNA FEZF1-AS1 could inhibit the proliferation and induce cell apoptosis in vitro and in vivo. Besides, lncRNA FEZF1-AS1 could maintain the stability of BZW2 mRNA by interacting IGF2BP1. Moreover, BZW2 silence also downregulated the proliferation but enhanced apoptosis of MM cells, while BZW2 overexpression had an opposite role, which dramatically reversed the regulatory roles of lncRNA FEZF1-AS1. Altogether, lncRNA FEZF1-AS1 facilitated MM development by regulating IGF2BP1/BZW2 signaling, suggesting that lncRNA FEZF1-AS1 might be a candidate for MM treatment.
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Affiliation(s)
- Xingxing Long
- Department of Hematology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan Province, China
| | - Feng Wen
- Department of Hematology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan Province, China
| | - Junjun Li
- Department of Hematology, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan Province, China
| | - Xiaoqing Huang
- Department of Blood Transfusion, The First Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan Province, China
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Wek RC, Anthony TG, Staschke KA. Surviving and Adapting to Stress: Translational Control and the Integrated Stress Response. Antioxid Redox Signal 2023; 39:351-373. [PMID: 36943285 PMCID: PMC10443206 DOI: 10.1089/ars.2022.0123] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/23/2023]
Abstract
Significance: Organisms adapt to changing environments by engaging cellular stress response pathways that serve to restore proteostasis and enhance survival. A primary adaptive mechanism is the integrated stress response (ISR), which features phosphorylation of the α subunit of eukaryotic translation initiation factor 2 (eIF2). Four eIF2α kinases respond to different stresses, enabling cells to rapidly control translation to optimize management of resources and reprogram gene expression for stress adaptation. Phosphorylation of eIF2 blocks its guanine nucleotide exchange factor, eIF2B, thus lowering the levels of eIF2 bound to GTP that is required to deliver initiator transfer RNA (tRNA) to ribosomes. While bulk messenger RNA (mRNA) translation can be sharply lowered by heightened phosphorylation of eIF2α, there are other gene transcripts whose translation is unchanged or preferentially translated. Among the preferentially translated genes is ATF4, which directs transcription of adaptive genes in the ISR. Recent Advances and Critical Issues: This review focuses on how eIF2α kinases function as first responders of stress, the mechanisms by which eIF2α phosphorylation and other stress signals regulate the exchange activity of eIF2B, and the processes by which the ISR triggers differential mRNA translation. To illustrate the synergy between stress pathways, we describe the mechanisms and functional significance of communication between the ISR and another key regulator of translation, mammalian/mechanistic target of rapamycin complex 1 (mTORC1), during acute and chronic amino acid insufficiency. Finally, we discuss the pathological conditions that stem from aberrant regulation of the ISR, as well as therapeutic strategies targeting the ISR to alleviate disease. Future Directions: Important topics for future ISR research are strategies for modulating this stress pathway in disease conditions and drug development, molecular processes for differential translation and the coordinate regulation of GCN2 and other stress pathways during physiological and pathological conditions. Antioxid. Redox Signal. 39, 351-373.
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Affiliation(s)
- Ronald C. Wek
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
| | - Tracy G. Anthony
- Department of Nutritional Sciences, Rutgers University, New Brunswick, New Jersey, USA
| | - Kirk A. Staschke
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana, USA
- Indiana University Melvin and Bren Simon Comprehensive Cancer Center, Indianapolis, Indiana, USA
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5
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Singh CR, Tani N, Nakamura A, Asano K. Mass spectrometry analysis of affinity-purified cytoplasmic translation initiation complexes from human and fly cells. STAR Protoc 2022; 3:101739. [PMID: 36181679 PMCID: PMC9529597 DOI: 10.1016/j.xpro.2022.101739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 07/25/2022] [Accepted: 09/08/2022] [Indexed: 11/05/2022] Open
Abstract
eIF5-mimic protein (5MP) controls translation through binding to the ribosomal pre-initiation complex (PIC) and alters non-AUG translation rates for cancer oncogenes and repeat-expansions in neurodegenerative diseases. Here, we describe a semi-quantitative protocol for detecting 5MP-associated proteins in cultured human and fly cells. We detail one-step anti-FLAG affinity purification and whole-lane mass spectrometry analysis of samples resolved by SDS-PAGE. This protocol allows for quantitative evaluation of the effect of 5MP mutations on its molecular interactions, to elucidate translational control by 5MP. For complete details on the use and execution of this protocol, please refer to Singh et al. (2021).
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Affiliation(s)
- Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Department of Pediatrics, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA; Department of Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA 17033, USA.
| | - Naoki Tani
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Akira Nakamura
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan.
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan; Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan.
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6
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Zhang J, Pi SB, Zhang N, Guo J, Zheng W, Leng L, Lin G, Fan HY. Translation regulatory factor BZW1 regulates preimplantation embryo development and compaction by restricting global non-AUG Initiation. Nat Commun 2022; 13:6621. [PMID: 36333315 PMCID: PMC9636173 DOI: 10.1038/s41467-022-34427-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022] Open
Abstract
Protein synthesis is an essential step in gene expression during the development of mammalian preimplantation embryos. This is a complex and highly regulated process. The accuracy of the translation initiation codon is important in various gene expression programs. However, the mechanisms that regulate AUG and non-AUG codon initiation in early embryos remain poorly understood. BZW1 is a key factor in determining the mRNA translation start codon. Here, we show that BZW1 is essential for early embryonic development in mice. Bzw1-knockdown embryos fail to undergo compaction, and show decreased blastocyst formation rates. We also observe defects in the differentiation capacity and implantation potential after Bzw1 interference. Further investigation revealed that Bzw1 knockdown causes the levels of translation initiation with CUG as the start codon to increase. The decline in BZW1 levels result in a decrease in protein synthesis in preimplantation embryos, whereas the total mRNA levels are not altered. Therefore, we concluded that BZW1 contributes to protein synthesis during early embryonic development by restricting non-AUG translational initiation.
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Affiliation(s)
- Jue Zhang
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, 410078, Changsha, China
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China
- College of Life Science, Hunan Normal University, 410006, Changsha, China
| | - Shuai-Bo Pi
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China
| | - Nan Zhang
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China
| | - Jing Guo
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, 410078, Changsha, China
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China
| | - Wei Zheng
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, 410078, Changsha, China
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China
| | - Lizhi Leng
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, 410078, Changsha, China
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China
| | - Ge Lin
- Clinical Research Center for Reproduction and Genetics in Hunan Province, Reproductive and Genetic Hospital of CITIC-XIANGYA, 410078, Changsha, China.
- NHC Key Laboratory of Human Stem and Reproductive Engineering, School of Basic Medical Science, Central South University, 410078, Changsha, China.
| | - Heng-Yu Fan
- Life Sciences Institute, Zhejiang University, 310058, Hangzhou, China.
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7
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Rubio A, Garland GD, Sfakianos A, Harvey RF, Willis AE. Aberrant protein synthesis and cancer development: The role of canonical eukaryotic initiation, elongation and termination factors in tumorigenesis. Semin Cancer Biol 2022; 86:151-165. [PMID: 35487398 DOI: 10.1016/j.semcancer.2022.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 04/11/2022] [Accepted: 04/20/2022] [Indexed: 01/27/2023]
Abstract
In tumourigenesis, oncogenes or dysregulated tumour suppressor genes alter the canonical translation machinery leading to a reprogramming of the translatome that, in turn, promotes the translation of selected mRNAs encoding proteins involved in proliferation and metastasis. It is therefore unsurprising that abnormal expression levels and activities of eukaryotic initiation factors (eIFs), elongation factors (eEFs) or termination factors (eRFs) are associated with poor outcome for patients with a wide range of cancers. In this review we discuss how RNA binding proteins (RBPs) within the canonical translation factor machinery are dysregulated in cancers and how targeting such proteins is leading to new therapeutic avenues.
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Affiliation(s)
- Angela Rubio
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Gavin D Garland
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Aristeidis Sfakianos
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Robert F Harvey
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK
| | - Anne E Willis
- MRC Toxicology Unit, University of Cambridge, Gleeson Building, Tennis Court Rd, Cambridge CB2 1QR, UK.
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8
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Baud A, Derbis M, Tutak K, Sobczak K. Partners in crime: Proteins implicated in
RNA
repeat expansion diseases. WIRES RNA 2022; 13:e1709. [PMID: 35229468 PMCID: PMC9539487 DOI: 10.1002/wrna.1709] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 12/07/2021] [Accepted: 12/08/2021] [Indexed: 11/06/2022]
Affiliation(s)
- Anna Baud
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Magdalena Derbis
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Katarzyna Tutak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
| | - Krzysztof Sobczak
- Department of Gene Expression Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University Poznan Poland
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9
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Zhang Y, Houchen CW, Li M. A Novel Translational Activation of HIF1α Promotes Pancreatic Cancer Growth Through Glycolytic Reprogramming. Gastroenterology 2022; 162:1040-1042. [PMID: 35120914 DOI: 10.1053/j.gastro.2022.01.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 01/21/2022] [Accepted: 01/21/2022] [Indexed: 12/25/2022]
Affiliation(s)
- Yuqing Zhang
- Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Courtney W Houchen
- Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Min Li
- Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma.
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Li Z, Ge Y, Dong J, Wang H, Zhao T, Wang X, Liu J, Gao S, Shi L, Yang S, Huang C, Hao J. BZW1 Facilitates Glycolysis and Promotes Tumor Growth in Pancreatic Ductal Adenocarcinoma Through Potentiating eIF2α Phosphorylation. Gastroenterology 2022; 162:1256-1271.e14. [PMID: 34951995 PMCID: PMC9436032 DOI: 10.1053/j.gastro.2021.12.249] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 11/23/2021] [Accepted: 12/16/2021] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Pancreatic ductal adenocarcinoma (PDAC) is characterized by severe metabolic stress due to fibrosis and poor vascularization. BZW1 is an eIF5-mimic protein involved in tumorigenesis and progression. The aim of this study was to investigate the role of BZW1 in metabolic stress resistance in PDAC. METHODS BZW1 expression was evaluated in human PDAC tissue microarray and PDAC cells. Glycolysis regulation of BZW1 and its correlation with glycolysis-related genes was analyzed. Tumor growth, cell proliferation, and apoptosis were evaluated in mice xenograft tumors and patient-derived organoids. RESULTS The results of bioinformatic screening identified that BZW1 was 1 of the top 3 genes favorable for tumor progression in PDAC. The analysis of our cohort confirmed that BZW1 was overexpressed in human PDAC tissues compared with nontumor tissues, and its abnormal expression was correlated with large tumor size and poor prognosis. BZW1 promoted cell proliferation and inhibited apoptosis in both mouse xenograft models and PDAC-derived organoids via facilitating glycolysis in the oxygen-glucose-deprivation condition. Mechanically, BZW1 served as an adaptor for PKR-like endoplasmic reticulum (ER) kinase (PERK), facilitated the phosphorylation of eIF2α, promoted internal ribosome entry site-dependent translation of HIF1α and c-Myc, and thereby boosted the Warburg effect. In organoid-based xenografts with high BZW1 levels, both the PERK/eIF2α phosphorylation inhibitor GSK2606414 and ISRIB significantly suppressed tumor growth and prolonged animal survival. CONCLUSIONS BZW1 is a key molecule in the internal ribosome entry site-dependent translation of HIF1α/c-Myc and plays crucial roles in the glycolysis of PDAC. BZW1 might serve as a therapeutic target for patients with pancreatic cancer.
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Affiliation(s)
- Zengxun Li
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Yi Ge
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Jie Dong
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Hongwei Wang
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Tiansuo Zhao
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Xiuchao Wang
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Jing Liu
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Song Gao
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China
| | - Lei Shi
- Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin, China
| | - Shengyu Yang
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
| | - Chongbiao Huang
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.
| | - Jihui Hao
- Department of Pancreatic Cancer, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, China.
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Nachmias B, Khan DH, Voisin V, Mer AS, Thomas GE, Segev N, St-Germain J, Hurren R, Gronda M, Botham A, Wang X, Maclean N, Seneviratne AK, Duong N, Xu C, Arruda A, Orouji E, Algouneh A, Hakem R, Shlush L, Minden MD, Raught B, Bader GD, Schimmer AD. IPO11 regulates the nuclear import of BZW1/2 and is necessary for AML cells and stem cells. Leukemia 2022; 36:1283-1295. [PMID: 35152270 PMCID: PMC9061300 DOI: 10.1038/s41375-022-01513-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 01/06/2022] [Accepted: 01/26/2022] [Indexed: 12/24/2022]
Abstract
AML cells are arranged in a hierarchy with stem/progenitor cells giving rise to more differentiated bulk cells. Despite the importance of stem/progenitors in the pathogenesis of AML, the determinants of the AML stem/progenitor state are not fully understood. Through a comparison of genes that are significant for growth and viability of AML cells by way of a CRISPR screen, with genes that are differentially expressed in leukemia stem cells (LSC), we identified importin 11 (IPO11) as a novel target in AML. Importin 11 (IPO11) is a member of the importin β family of proteins that mediate transport of proteins across the nuclear membrane. In AML, knockdown of IPO11 decreased growth, reduced engraftment potential of LSC, and induced differentiation. Mechanistically, we identified the transcription factors BZW1 and BZW2 as novel cargo of IPO11. We further show that BZW1/2 mediate a transcriptional signature that promotes stemness and survival of LSC. Thus, we demonstrate for the first time how specific cytoplasmic-nuclear regulation supports stem-like transcriptional signature in relapsed AML.
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12
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Paul EE, Lin KY, Gamble N, Tsai AWL, Swan SHK, Yang Y, Doran M, Marintchev A. Dynamic interaction network involving the conserved intrinsically disordered regions in human eIF5. Biophys Chem 2022; 281:106740. [PMID: 34923394 PMCID: PMC8741751 DOI: 10.1016/j.bpc.2021.106740] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 12/05/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023]
Abstract
Translation initiation in eukaryotes requires multiple eukaryotic translation initiation factors (eIFs) and involves continuous remodeling of the ribosomal preinitiation complex (PIC). The GTPase eIF2 brings the initiator Met-tRNAi to the PIC. Upon start codon selection and GTP hydrolysis, promoted by eIF5, eIF2-GDP is released in complex with eIF5. Here, we report that two intrinsically disordered regions (IDRs) in eIF5, the DWEAR motif and the C-terminal tail (CTT) dynamically contact the folded C-terminal domain (CTD) and compete with each other. The eIF5-CTD•CTT interaction favors eIF2β binding to eIF5-CTD, whereas the eIF5-CTD•DWEAR interaction favors eIF1A binding, which suggests how intramolecular contact rearrangement could play a role in PIC remodeling. We show that eIF5 phosphorylation by CK2, which is known to stimulate translation and cell proliferation, significantly increases the eIF5 affinity for eIF2. Our results also indicate that the eIF2β subunit has at least two, and likely three eIF5-binding sites.
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Affiliation(s)
- Eleanor Elise Paul
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Kay Ying Lin
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Nathan Gamble
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Amy Wei-Lun Tsai
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Simon H. K. Swan
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Yu Yang
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Matthew Doran
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
| | - Assen Marintchev
- Department of Physiology & Biophysics, Boston University School of Medicine, 700 Albany St. W336, Boston, MA 02118, USA
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13
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Sénéchal P, Robert F, Cencic R, Yanagiya A, Chu J, Sonenberg N, Paquet M, Pelletier J. Assessing eukaryotic initiation factor 4F subunit essentiality by CRISPR-induced gene ablation in the mouse. Cell Mol Life Sci 2021; 78:6709-6719. [PMID: 34559254 PMCID: PMC11073133 DOI: 10.1007/s00018-021-03940-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 08/31/2021] [Accepted: 09/10/2021] [Indexed: 01/16/2023]
Abstract
Eukaryotic initiation factor (eIF) 4F plays a central role in the ribosome recruitment phase of cap-dependent translation. This heterotrimeric complex consists of a cap binding subunit (eIF4E), a DEAD-box RNA helicase (eIF4A), and a large bridging protein (eIF4G). In mammalian cells, there are two genes encoding eIF4A (eIF4A1 and eIF4A2) and eIF4G (eIF4G1 and eIF4G3) paralogs that can assemble into eIF4F complexes. To query the essential nature of the eIF4F subunits in normal development, we used CRISPR/Cas9 to generate mouse strains with targeted ablation of each gene encoding the different eIF4F subunits. We find that Eif4e, Eif4g1, and Eif4a1 are essential for viability in the mouse, whereas Eif4g3 and Eif4a2 are not. However, Eif4g3 and Eif4a2 do play essential roles in spermatogenesis. Crossing of these strains to the lymphoma-prone Eμ-Myc mouse model revealed that heterozygosity at the Eif4e or Eif4a1 loci significantly delayed tumor onset. Lastly, tumors derived from Eif4e∆38 fs/+/Eμ-Myc or Eif4a1∆5 fs/+/Eμ-Myc mice show increased sensitivity to the chemotherapeutic agent doxorubicin, in vivo. Our study reveals that eIF4A2 and eIF4G3 play non-essential roles in gene expression regulation during embryogenesis; whereas reductions in eIF4E or eIF4A1 levels are protective against tumor development in a murine Myc-driven lymphoma setting.
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Affiliation(s)
- Patrick Sénéchal
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Francis Robert
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Regina Cencic
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Akiko Yanagiya
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
- Cell Signal Unit, Okinawa Institute of Science and Technology, Okinawa, 904-0495, Japan
| | - Jennifer Chu
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02138, USA
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada
- Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, QC, H3A 1A3, Canada
| | - Marilène Paquet
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, QC, H3G 1Y6, Canada.
- Department of Oncology, McGill University, Montreal, QC, H3A 1G5, Canada.
- Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, QC, H3A 1A3, Canada.
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14
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Singh CR, Glineburg MR, Moore C, Tani N, Jaiswal R, Zou Y, Aube E, Gillaspie S, Thornton M, Cecil A, Hilgers M, Takasu A, Asano I, Asano M, Escalante CR, Nakamura A, Todd PK, Asano K. Human oncoprotein 5MP suppresses general and repeat-associated non-AUG translation via eIF3 by a common mechanism. Cell Rep 2021; 36:109376. [PMID: 34260931 PMCID: PMC8363759 DOI: 10.1016/j.celrep.2021.109376] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/11/2021] [Accepted: 06/17/2021] [Indexed: 11/15/2022] Open
Abstract
eIF5-mimic protein (5MP) is a translational regulatory protein that binds the small ribosomal subunit and modulates its activity. 5MP is proposed to reprogram non-AUG translation rates for oncogenes in cancer, but its role in controlling non-AUG initiated synthesis of deleterious repeat-peptide products, such as FMRpolyG observed in fragile-X-associated tremor ataxia syndrome (FXTAS), is unknown. Here, we show that 5MP can suppress both general and repeat-associated non-AUG (RAN) translation by a common mechanism in a manner dependent on its interaction with eIF3. Essentially, 5MP displaces eIF5 through the eIF3c subunit within the preinitiation complex (PIC), thereby increasing the accuracy of initiation. In Drosophila, 5MP/Kra represses neuronal toxicity and enhances the lifespan in an FXTAS disease model. These results implicate 5MP in protecting cells from unwanted byproducts of non-AUG translation in neurodegeneration.
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Affiliation(s)
- Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Chelsea Moore
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Naoki Tani
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Rahul Jaiswal
- Department of Physiology and Biophysics, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
| | - Ye Zou
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS 66506, USA
| | - Eric Aube
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ariana Cecil
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Madelyn Hilgers
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Azuma Takasu
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Izumi Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Masayo Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carlos R Escalante
- Department of Physiology and Biophysics, Virginia Commonwealth University, School of Medicine, Richmond, VA 23298, USA
| | - Akira Nakamura
- Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA; Ann Arbor VA Medical Center, Ann Arbor, MI 48105, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA; Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan; Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530, Japan.
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15
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Li G, Lu A, Chen A, Geng S, Xu Y, Chen X, Yang J. BZW2/5MP1 acts as a promising target in hepatocellular carcinoma. J Cancer 2021; 12:5125-5135. [PMID: 34335929 PMCID: PMC8317536 DOI: 10.7150/jca.53282] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 06/09/2021] [Indexed: 11/17/2022] Open
Abstract
Basic leucine zipper and W2 domain 2 (BZW2), also known as 5MP1, is a protein related to translation regulation. Evidence from previous studies indicates that BZW2 is involved in tumorigenesis in several cancers. However, little is known about the role of BZW2 in hepatocellular carcinoma (HCC). In this study, we first analyzed the gene expression profile of BZW2 in multiple HCC datasets. Next, we explored the biological effects of BZW2 in HCC cell lines. BZW2 was overexpressed in different HCC cohorts. Multivariate analysis confirmed that increased BZW2 expression is an independent prognostic indicator of shorter overall survival. BZW2 coexpressed genes were mainly enriched in the biological processes of ribonucleoprotein complex biogenesis, rRNA metabolism, translational initiation, and negative regulation of metabolic processes. BZW2 depletion reduced proliferation, clonality, and invasion and increased apoptosis in MHCC97-H cells. Furthermore, BZW2 overexpression or knockdown enhanced or impaired c-Myc expression, respectively. Overall, these findings identified BZW2 as a biomarker of HCC and provided novel insight that the effect of BZW2 on the translatome is a potential mechanism that promotes HCC progression via the c-Myc pathway.
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Affiliation(s)
- Guoxiong Li
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Anqian Lu
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Anna Chen
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China.,Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Shuang Geng
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Yu Xu
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Xin Chen
- Department of Gastroenterology, Affiliated Hospital of Hangzhou Normal University, Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
| | - Jin Yang
- Department of Translational Medicine Center, Affiliated Hospital of Hangzhou Normal University, Institute of Hepatology and Metabolic Diseases of Hangzhou Normal University, Hangzhou, Zhejiang 310015, P.R. China
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16
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Asano K. Origin of translational control by eIF2α phosphorylation: insights from genome-wide translational profiling studies in fission yeast. Curr Genet 2021; 67:359-368. [PMID: 33420908 PMCID: PMC8140999 DOI: 10.1007/s00294-020-01149-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 01/14/2023]
Abstract
During amino acid limitation, the protein kinase Gcn2 phosphorylates the α subunit of eIF2, thereby regulating mRNA translation. In yeast Saccharomyces cerevisiae and mammals, eIF2α phosphorylation regulates translation of related transcription factors Gcn4 and Atf4 through upstream open reading frames (uORFs) to activate transcription genome wide. However, mammals encode three more eIF2α kinases activated by distinct stimuli. Did the translational control system involving eIF2α phosphorylation evolve from so simple (as found in yeast S. cerevisiae) to complex (as found in humans)? Recent genome-wide translational profiling studies of amino acid starvation response in the fission yeast Schizosaccharomyces pombe provide an unexpected answer to this question.
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Affiliation(s)
- Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS, 66506, USA.
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
- Hiroshima Research Center for Healthy Aging, Hiroshima University, Higashi-Hiroshima, Hiroshima, 739-8530, Japan.
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17
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Song P, Yang F, Jin H, Wang X. The regulation of protein translation and its implications for cancer. Signal Transduct Target Ther 2021; 6:68. [PMID: 33597534 PMCID: PMC7889628 DOI: 10.1038/s41392-020-00444-9] [Citation(s) in RCA: 52] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 08/30/2020] [Accepted: 12/06/2020] [Indexed: 02/08/2023] Open
Abstract
In addition to the deregulation of gene transcriptions and post-translational protein modifications, the aberrant translation from mRNAs to proteins plays an important role in the pathogenesis of various cancers. Targeting mRNA translation are expected to become potential approaches for anticancer treatments. Protein translation is affected by many factors including translation initiation factors and RNA-binding proteins. Recently, modifications of mRNAs mainly N6-methyladenine (m6A) modification and noncoding RNAs, such as microRNAs and long noncoding RNAs are involved. In this review, we generally summarized the recent advances on the regulation of protein translation by the interplay between mRNA modifications and ncRNAs. By doing so, we hope this review could offer some hints for the development of novel approaches in precision therapy of human cancers.
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Affiliation(s)
- Ping Song
- grid.13402.340000 0004 1759 700XDepartment of Medical Oncology, Cancer Institute of Zhejiang University, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Fan Yang
- grid.13402.340000 0004 1759 700XDepartment of Hepatobiliary and Pancreatic Surgery, First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Hongchuan Jin
- grid.13402.340000 0004 1759 700XKey Lab of Biotherapy in Zhejiang, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
| | - Xian Wang
- grid.13402.340000 0004 1759 700XDepartment of Medical Oncology, Cancer Institute of Zhejiang University, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang China
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18
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Wang X, Li F, Chen Z, Yang B, Komatsu S, Zhou S. Proteomic analysis reveals the effects of melatonin on soybean root tips under flooding stress. J Proteomics 2021; 232:104064. [PMID: 33276190 DOI: 10.1016/j.jprot.2020.104064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2020] [Revised: 11/14/2020] [Accepted: 11/22/2020] [Indexed: 11/30/2022]
Abstract
Flooding constrains soybean growth, while melatonin enhances the ability of plants to tolerate abiotic stresses. To interpret the melatonin-mediated flooding response in soybeans, proteomic analysis was performed in root tips. Retarded growth and severe cell death were observed in flooded soybeans, but these phenotypes were ameliorated by melatonin treatment. A total of 634, 1401, and 1205 proteins were identified under control, flood, and flood plus melatonin conditions, respectively; and these proteins were predominantly associated with metabolism of protein, RNA, and the cell wall. Among these melatonin-induced proteins, eukaryotic aspartyl protease family protein was increased after flood compared with melatonin treatment group, in accordance with its upregulated transcript levels during stress. Eukaryotic translation initiation factor 5A was decreased after flood compared with melatonin. When stress was prolonged, its transcript levels were upregulated by flood, while they were not changed by melatonin. Furthermore, 13-hydroxylupanine O-tigloyltransferase was decreased by flood compared with melatonin; however, its transcription was upregulated by melatonin. In addition, reduced lignification in root tips of flooded soybeans was restored by melatonin. These results suggest that factors related to protein degradation and functional states of RNA play critical roles in promoting the effects of melatonin on soybean plants under flooding. SIGNIFICANCE: Flooding stress threatens soybean growth, while melatonin treatment enhances plant tolerance to stress stimuli. To examine the effects of melatonin on flooded soybeans, morphological analysis was performed. Melatonin promoted soybean growth as judged from greater fresh weight of plant, longer seedling length, and less evident cell death in flooding-stressed soybeans treated with melatonin than those plants exposed to flood alone. Proteomic analysis was conducted to explore the promoting effects of melatonin on soybeans under flooding stress. As a result, metabolism of protein metabolism, RNA regulation, and cell wall was enriched by proteins identified under control, flood, and flood plus melatonin conditions. Among these melatonin-induced proteins, abundance of eukaryotic aspartyl protease family protein, eukaryotic translation initiation factor 5A, and 13-hydroxylupanine O-tigloyltransferase displayed similar change patterns between the control and melatonin compared with flood; and transcript levels of genes encoding these proteins responded to flooding stress and melatonin treatment. In addition, activated cell degradation, expanded intercellular spaces, and reduced lignification in root tips of flooded soybeans were ameliorated by melatonin treatment.
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Affiliation(s)
- Xin Wang
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Fang Li
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Zhenyuan Chen
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China
| | - Bingxian Yang
- College of Life Sciences and Medicine, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | - Setsuko Komatsu
- Faculty of Environmental and Information Sciences, Fukui University of Technology, Fukui 910-8505, Japan
| | - Shunli Zhou
- College of Agronomy and Biotechnology, China Agricultural University, Beijing 100193, China.
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19
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Unusually efficient CUG initiation of an overlapping reading frame in POLG mRNA yields novel protein POLGARF. Proc Natl Acad Sci U S A 2020; 117:24936-24946. [PMID: 32958672 DOI: 10.1073/pnas.2001433117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
While near-cognate codons are frequently used for translation initiation in eukaryotes, their efficiencies are usually low (<10% compared to an AUG in optimal context). Here, we describe a rare case of highly efficient near-cognate initiation. A CUG triplet located in the 5' leader of POLG messenger RNA (mRNA) initiates almost as efficiently (∼60 to 70%) as an AUG in optimal context. This CUG directs translation of a conserved 260-triplet-long overlapping open reading frame (ORF), which we call POLGARF (POLG Alternative Reading Frame). Translation of a short upstream ORF 5' of this CUG governs the ratio between POLG (the catalytic subunit of mitochondrial DNA polymerase) and POLGARF synthesized from a single POLG mRNA. Functional investigation of POLGARF suggests a role in extracellular signaling. While unprocessed POLGARF localizes to the nucleoli together with its interacting partner C1QBP, serum stimulation results in rapid cleavage and secretion of a POLGARF C-terminal fragment. Phylogenetic analysis shows that POLGARF evolved ∼160 million y ago due to a mammalian-wide interspersed repeat (MIR) transposition into the 5' leader sequence of the mammalian POLG gene, which became fixed in placental mammals. This discovery of POLGARF unveils a previously undescribed mechanism of de novo protein-coding gene evolution.
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20
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Huang L, Chen S, Fan H, Ai F, Sheng W. BZW2 promotes the malignant progression of colorectal cancer via activating the ERK/MAPK pathway. J Cell Physiol 2019; 235:4834-4842. [PMID: 31643092 DOI: 10.1002/jcp.29361] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 10/07/2019] [Indexed: 01/21/2023]
Abstract
Colorectal cancer (CRC) is one of the most prevalent malignant solid cancers worldwide involving the dysregulation of multiple signaling molecules. However, the role and corresponding mechanism of basic leucine zipper and W2 domains 2 (BZW2) in CRC development, to our knowledge, has not been reported. We found BZW2 was overexpressed in human CRC tissues compared with that in paired adjacent colorectal samples. BZW2 overexpression was closely associated with tumor T stage (p = .030), metastatic lymph nodes (p = .037), TNM stage (p = .018) and the worse prognosis of CRC patients (p = .009). Moreover, BZW2 was an independent disadvantage prognostic factor (p = .031). BZW2 also showed an increased expression in different invasive CRC cell lines. Its silencing and overexpression diminished and increased cell proliferation, invasion, and migration in Colo205 and HCT116 cells via specifically activating of extracellular-signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling. Moreover, ERK/MAPK inhibitor PD98059 reverse the enhancement of cell proliferation, invasion, and migration in BZW2 overexpressing HCT116 cells. BZW2 silencing also inhibited subcutaneous tumors growth and p-ERK expression in vivo. BZW2 promotes the malignant progression of CRC via activating ERK/MAPK signaling, which provided a promising gene target therapy for CRC.
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Affiliation(s)
- Longping Huang
- Department of General and Hepatobiliary Surgery, The Fourth People's Hospital of Shenyang city, Shenyang, China
| | - Si Chen
- Department of Anesthesiology, The Fourth People's Hospital of Shenyang city, Shenyang, China
| | - Haijun Fan
- Department of General and Hepatobiliary Surgery, The Fourth People's Hospital of Shenyang city, Shenyang, China
| | - Fan Ai
- Department of General and Hepatobiliary Surgery, The Fourth People's Hospital of Shenyang city, Shenyang, China
| | - Weiwei Sheng
- Department of Gastrointestinal Surgery, The First Hospital, China Medical University, Shenyang, China
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21
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Linsalata AE, He F, Malik AM, Glineburg MR, Green KM, Natla S, Flores BN, Krans A, Archbold HC, Fedak SJ, Barmada SJ, Todd PK. DDX3X and specific initiation factors modulate FMR1 repeat-associated non-AUG-initiated translation. EMBO Rep 2019; 20:e47498. [PMID: 31347257 DOI: 10.15252/embr.201847498] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 06/19/2019] [Accepted: 06/26/2019] [Indexed: 12/12/2022] Open
Abstract
A CGG trinucleotide repeat expansion in the 5' UTR of FMR1 causes the neurodegenerative disorder Fragile X-associated tremor/ataxia syndrome (FXTAS). This repeat supports a non-canonical mode of protein synthesis known as repeat-associated, non-AUG (RAN) translation. The mechanism underlying RAN translation at CGG repeats remains unclear. To identify modifiers of RAN translation and potential therapeutic targets, we performed a candidate-based screen of eukaryotic initiation factors and RNA helicases in cell-based assays and a Drosophila melanogaster model of FXTAS. We identified multiple modifiers of toxicity and RAN translation from an expanded CGG repeat in the context of the FMR1 5'UTR. These include the DEAD-box RNA helicase belle/DDX3X, the helicase accessory factors EIF4B/4H, and the start codon selectivity factors EIF1 and EIF5. Disrupting belle/DDX3X selectively inhibited FMR1 RAN translation in Drosophila in vivo and cultured human cells, and mitigated repeat-induced toxicity in Drosophila and primary rodent neurons. These findings implicate RNA secondary structure and start codon fidelity as critical elements mediating FMR1 RAN translation and identify potential targets for treating repeat-associated neurodegeneration.
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Affiliation(s)
- Alexander E Linsalata
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Fang He
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.,Department of Biological and Health Sciences, Texas A&M University, Kingsville, Kingsville, TX, USA
| | - Ahmed M Malik
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | | | - Katelyn M Green
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Sam Natla
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Brittany N Flores
- Cellular and Molecular Biology Graduate Program, University of Michigan, Ann Arbor, MI, USA.,Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Amy Krans
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | | | - Stephen J Fedak
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Sami J Barmada
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.,Ann Arbor VA Medical Center, Ann Arbor, MI, USA
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22
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Robichaud N, Sonenberg N, Ruggero D, Schneider RJ. Translational Control in Cancer. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032896. [PMID: 29959193 DOI: 10.1101/cshperspect.a032896] [Citation(s) in RCA: 153] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The translation of messenger RNAs (mRNAs) into proteins is a key event in the regulation of gene expression. This is especially true in the cancer setting, as many oncogenes and transforming events are regulated at this level. Cancer-promoting factors that are translationally regulated include cyclins, antiapoptotic factors, proangiogenic factors, regulators of cell metabolism, prometastatic factors, immune modulators, and proteins involved in DNA repair. This review discusses the diverse means by which cancer cells deregulate and reprogram translation, and the resulting oncogenic impacts, providing insights into the complexity of translational control in cancer and its targeting for cancer therapy.
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Affiliation(s)
- Nathaniel Robichaud
- Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Nahum Sonenberg
- Goodman Cancer Research Centre and Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada
| | - Davide Ruggero
- Helen Diller Family Comprehensive Cancer Center, and Departments of Urology and of Cellular and Molecular Pharmacology, University of California, San Francisco, California 94158
| | - Robert J Schneider
- NYU School of Medicine, Alexandria Center for Life Science, New York, New York 10016
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23
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Venkata Subbaiah KC, Wu J, Potdar A, Yao P. hnRNP L-mediated RNA switches function as a hypoxia-induced translational regulon. Biochem Biophys Res Commun 2019; 516:753-759. [PMID: 31255281 DOI: 10.1016/j.bbrc.2019.06.106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 06/19/2019] [Indexed: 11/24/2022]
Abstract
The GAIT (gamma-interferon-activated inhibitor of translation) complex or miR-297-RISC (RNA-induced silencing complex), together with hnRNP L or hnRNP L-bearing complex, operates an RNA switch in myeloid cells that regulates stress-dependent expression of vascular endothelial growth factor-A (VEGFA). Here, we have shown that hnRNP L directs multiple hypoxia-inducible RNA switches simultaneously and regulates expression of these oncogenic genes in addition to VEGFA. Bioinformatic and polysome profiling-microarray screens have identified DNM1L (Dynamin 1-like) and PHF21A (PHD finger protein 21A) mRNAs as regulated at the translational level by GAIT-dependent, hnRNP L-directed RNA switches. We have also uncovered CDK6 (Cyclin dependent kinase 6), MKLN1 (Muskelin 1) and EIF5 (Eukaryotic initiation factor 5) as novel miR-297-dependent, hnRNP L-directed RNA switch transcripts. Src Kinase is required for the phosphorylation of hnRNP L and activation of the RNA switch pathway. Knockdown of hnRNP L sensitizes the human U937 monocytic cells under hypoxia stress but not in normoxia via inducing cell apoptosis partially due to the reduced translation of hnRNP L target mRNAs. Collectively, our findings suggest that commonly controlled genes by the hnRNP L-directed RNA switches form a translational regulon that promotes hypoxia resistance and cell survival.
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Affiliation(s)
- Kadiam C Venkata Subbaiah
- Aab Cardiovascular Research Institute, Department of Medicine, Department of Biochemistry and Biophysics, Center for RNA Biology, Center for Biomedical Informatics, University of Rochester Medical Center, Rochester, NY, USA
| | - Jiangbin Wu
- Aab Cardiovascular Research Institute, Department of Medicine, Department of Biochemistry and Biophysics, Center for RNA Biology, Center for Biomedical Informatics, University of Rochester Medical Center, Rochester, NY, USA
| | - Alka Potdar
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Peng Yao
- Aab Cardiovascular Research Institute, Department of Medicine, Department of Biochemistry and Biophysics, Center for RNA Biology, Center for Biomedical Informatics, University of Rochester Medical Center, Rochester, NY, USA.
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24
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Sato K, Masuda T, Hu Q, Tobo T, Gillaspie S, Niida A, Thornton M, Kuroda Y, Eguchi H, Nakagawa T, Asano K, Mimori K. Novel oncogene 5MP1 reprograms c-Myc translation initiation to drive malignant phenotypes in colorectal cancer. EBioMedicine 2019; 44:387-402. [PMID: 31175057 PMCID: PMC6606960 DOI: 10.1016/j.ebiom.2019.05.058] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/26/2019] [Accepted: 05/28/2019] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Translational reprogramming through controlled initiation from non-AUG start codons is considered a crucial driving force in tumorigenesis and tumor progression. However, its clinical impact and underlying mechanism are not fully understood. METHODS Using a bioinformatics approach, we identified translation initiation regulator 5MP1/BZW2 on chromosome 7p as a potential oncogenic driver gene in colorectal cancer (CRC), and explored the biological effect of 5MP1 in CRC in vitro or in vivo. Pathway analysis was performed to identify the downstream target of 5MP1, which was verified with transcriptomic and biochemical analyses. Finally, we assessed the clinical significance of 5MP1 expression in CRC patients. FINDINGS 5MP1 was ubiquitously amplified and overexpressed in CRC. 5MP1 promoted tumor growth and induced cell cycle progression of CRC. c-Myc was identified as its potential downstream effector. c-Myc has two in-frame start codons, AUG and CUG (non-AUG) located upstream of the AUG. 5MP1 expression increased the AUG-initiated c-Myc isoform relative to the CUG-initiated isoform. The AUG-initiated c-Myc isoform displayed higher protein stability and a stronger transactivation activity for oncogenic pathways than the CUG-initiated isoform, accounting for 5MP1-driven cell cycle progression and tumor growth. Clinically, high 5MP1 expression predicts poor survival of CRC patients. INTERPRETATION 5MP1 is a novel oncogene that reprograms c-Myc translation in CRC. 5MP1 could be a potential therapeutic target to overcome therapeutic resistance conferred by tumor heterogeneity of CRC. FUND: Japan Society for the Promotion of Science; Priority Issue on Post-K computer; National Institutes of Health; National Science Foundation; KSU Johnson Cancer Center.
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Affiliation(s)
- Kuniaki Sato
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan; Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Higashi-ku, Fukuoka, Fukuoka 860-8556, Japan
| | - Takaaki Masuda
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Qingjiang Hu
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Taro Tobo
- Department of Clinical Laboratory Medicine and Pathology, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Atsushi Niida
- Division of Health Medical Computational Science, Health Intelligence Center, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yousuke Kuroda
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Hidetoshi Eguchi
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan
| | - Takashi Nakagawa
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Higashi-ku, Fukuoka, Fukuoka 860-8556, Japan
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA.
| | - Koshi Mimori
- Department of Surgery, Kyushu University Beppu Hospital, 4546 Tsurumihara, Beppu, Oita 874-0838, Japan.
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25
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Rodriguez CM, Chun SY, Mills RE, Todd PK. Translation of upstream open reading frames in a model of neuronal differentiation. BMC Genomics 2019; 20:391. [PMID: 31109297 PMCID: PMC6528255 DOI: 10.1186/s12864-019-5775-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/07/2019] [Indexed: 12/17/2022] Open
Abstract
Background Upstream open reading frames (uORFs) initiate translation within mRNA 5′ leaders, and have the potential to alter main coding sequence (CDS) translation on transcripts in which they reside. Ribosome profiling (RP) studies suggest that translating ribosomes are pervasive within 5′ leaders across model systems. However, the significance of this observation remains unclear. To explore a role for uORF usage in a model of neuronal differentiation, we performed RP on undifferentiated and differentiated human neuroblastoma cells. Results Using a spectral coherence algorithm (SPECtre), we identify 4954 consistently translated uORFs across 31% of all neuroblastoma transcripts. These uORFs predominantly utilize non-AUG initiation codons and exhibit translational efficiencies (TE) comparable to annotated coding regions. On a population basis, the global impact of both AUG and non-AUG initiated uORFs on basal CDS translation were small, even when analysis is limited to conserved and consistently translated uORFs. However, uORFs did alter the translation of a subset of genes, including the Diamond-Blackfan Anemia associated ribosomal gene RPS24. With retinoic acid induced differentiation, we observed an overall positive correlation in translational shifts between uORF/CDS pairs. However, CDSs downstream of uORFs show smaller shifts in TE with differentiation relative to CDSs without a predicted uORF, suggesting that uORF translation buffers cell state dependent fluctuations in CDS translation. Conclusion This work provides insights into the dynamic relationships and potential regulatory functions of uORF/CDS pairs in a model of neuronal differentiation. Electronic supplementary material The online version of this article (10.1186/s12864-019-5775-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Caitlin M Rodriguez
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.,Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | - Sang Y Chun
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Ryan E Mills
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI, 48109, USA. .,Department of Human Genetics, University of Michigan, Ann Arbor, MI, 48109, USA.
| | - Peter K Todd
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA. .,VA Ann Arbor Healthcare System, Ann Arbor, MI, USA.
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26
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Hafirassou ML, Meertens L, Umaña-Diaz C, Labeau A, Dejarnac O, Bonnet-Madin L, Kümmerer BM, Delaugerre C, Roingeard P, Vidalain PO, Amara A. A Global Interactome Map of the Dengue Virus NS1 Identifies Virus Restriction and Dependency Host Factors. Cell Rep 2019; 21:3900-3913. [PMID: 29281836 DOI: 10.1016/j.celrep.2017.11.094] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 10/11/2017] [Accepted: 11/28/2017] [Indexed: 12/25/2022] Open
Abstract
Dengue virus (DENV) infections cause the most prevalent mosquito-borne viral disease worldwide, for which no therapies are available. DENV encodes seven non-structural (NS) proteins that co-assemble and recruit poorly characterized host factors to form the DENV replication complex essential for viral infection. Here, we provide a global proteomic analysis of the human host factors that interact with the DENV NS1 protein. Combined with a functional RNAi screen, this study reveals a comprehensive network of host cellular processes involved in DENV infection and identifies DENV host restriction and dependency factors. We highlight an important role of RACK1 and the chaperonin TRiC (CCT) and oligosaccharyltransferase (OST) complexes during DENV replication. We further show that the OST complex mediates NS1 and NS4B glycosylation, and pharmacological inhibition of its N-glycosylation function strongly impairs DENV infection. In conclusion, our study provides a global interactome of the DENV NS1 and identifies host factors targetable for antiviral therapies.
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Affiliation(s)
- Mohamed Lamine Hafirassou
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France.
| | - Laurent Meertens
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France
| | - Claudia Umaña-Diaz
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France
| | - Athena Labeau
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France
| | - Ophelie Dejarnac
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France
| | - Lucie Bonnet-Madin
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France
| | - Beate M Kümmerer
- Institute of Virology, University of Bonn Medical Centre, Bonn, Germany
| | | | - Philippe Roingeard
- INSERM U966 MAVIVH, Faculté de Médecine, Université de Tours, Tours, France
| | - Pierre-Olivier Vidalain
- Equipe Chimie & Biologie, Modélisation et Immunologie pour la Thérapie, Université Paris Descartes, CNRS UMR 8601, Paris, France
| | - Ali Amara
- INSERM U944, CNRS UMR 7212, Institut Universitaire d'Hématologie, Sorbonne Paris Cité, Université Paris Diderot, Hôpital Saint Louis, 75010 Paris, France.
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Wang CHJ, Chidiac P. RGS2 promotes the translation of stress-associated proteins ATF4 and CHOP via its eIF2B-inhibitory domain. Cell Signal 2019; 59:163-170. [PMID: 30826455 DOI: 10.1016/j.cellsig.2019.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 02/15/2019] [Accepted: 02/26/2019] [Indexed: 12/25/2022]
Abstract
Regulator of G protein signaling 2 (RGS2) is upregulated by multiple forms of stress and can augment translational attenuation associated with the phosphorylation of the initiation factor eIF2, a hallmark of several stress-induced coping mechanisms. Under stress-induced translational inhibition, key factors, such as ATF4, are selectively expressed via alternative translation mechanisms. These factors are known to regulate molecular switches that control cell fate by regulating pro-survival and pro-apoptotic signals. The molecular mechanisms that balance these opposing responses to stresses are unclear. The present results suggest that RGS2 may be an important regulatory component in the cellular stress response through its translational control abilities. Previously, we have shown that RGS2 can interact with the translation initiation factor, eIF2B, and inhibit de novo protein synthesis. Here, we demonstrate that the expression of either full length RGS2 or its eIF2B-interacting domain (RGS2eb) significantly increases levels of ATF4 and CHOP, both of which are linked to stress-induced apoptosis. Furthermore, we show that these effects are translationally regulated and independent of eIF2 phosphorylation. The present results thus point to a novel function of RGS2 in the stress response directly related to its ability to reduce global protein synthesis.
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Affiliation(s)
- Chang-Hui Jenny Wang
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada
| | - Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario N6A 5C1, Canada; Department of Biology, Faculty of Science, University of Western Ontario, London, Ontario N6A 5B7, Canada.
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28
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Ross JA, Bressler KR, Thakor N. Eukaryotic Initiation Factor 5B (eIF5B) Cooperates with eIF1A and eIF5 to Facilitate uORF2-Mediated Repression of ATF4 Translation. Int J Mol Sci 2018; 19:E4032. [PMID: 30551605 PMCID: PMC6321046 DOI: 10.3390/ijms19124032] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 12/08/2018] [Accepted: 12/10/2018] [Indexed: 12/20/2022] Open
Abstract
A variety of cellular stresses lead to global translation attenuation due to phosphorylation of the alpha subunit of eukaryotic initiation factor 2 (eIF2), which decreases the availability of the eIF2-GTP-Met-tRNAi ternary complex. However, a subset of mRNAs continues to be translated by non-canonical mechanisms under these conditions. In fact, although translation initiation of activating transcription factor 4 (ATF4) is normally repressed by an upstream open reading frame (uORF), a decreased availability of ternary complex leads to increased translation of the main ATF4-coding ORF. We show here that siRNA-mediated depletion of eIF5B-which can substitute for eIF2 in delivering Met-tRNAi-leads to increased levels of ATF4 protein in mammalian cells. This de-repression is not due to phosphorylation of eIF2α under conditions of eIF5B depletion. Although eIF5B depletion leads to a modest increase in the steady-state levels of ATF4 mRNA, we show by polysome profiling that the depletion of eIF5B enhances ATF4 expression primarily at the level of translation. Moreover, eIF5B silencing increases the expression of an ATF4-luciferase translational reporter by a mechanism requiring the repressive uORF2. Further experiments suggest that eIF5B cooperates with eIF1A and eIF5, but not eIF2A, to facilitate the uORF2-mediated repression of ATF4 translation.
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Affiliation(s)
- Joseph A Ross
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Kamiko R Bressler
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
| | - Nehal Thakor
- Department of Chemistry and Biochemistry, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
- Canadian Centre for Behavioral Neuroscience (CCBN), Department of Neuroscience, University of Lethbridge, 4401 University Drive W, Lethbridge, AB T1K 3M4, Canada.
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, 3280 Hospital Drive NW, Calgary, AB T2N 4Z6, Canada.
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29
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Pavitt GD. Regulation of translation initiation factor eIF2B at the hub of the integrated stress response. WILEY INTERDISCIPLINARY REVIEWS-RNA 2018; 9:e1491. [PMID: 29989343 DOI: 10.1002/wrna.1491] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/08/2018] [Accepted: 05/22/2018] [Indexed: 12/29/2022]
Abstract
Phosphorylation of the translation initiation factor eIF2 is one of the most widely used and well-studied mechanisms cells use to respond to diverse cellular stresses. Known as the integrated stress response (ISR), the control pathway uses modulation of protein synthesis to reprogram gene expression and restore homeostasis. Here the current knowledge of the molecular mechanisms of eIF2 activation and its control by phosphorylation at a single-conserved phosphorylation site, serine 51 are discussed with a major focus on the regulatory roles of eIF2B and eIF5 where a current molecular view of ISR control of eIF2B activity is presented. How genetic disorders affect eIF2 or eIF2B is discussed, as are syndromes where excess signaling through the ISR is a component. Finally, studies into the action of recently identified compounds that modulate the ISR in experimental systems are discussed; these suggest that eIF2B is a potential therapeutic target for a wide range of conditions. This article is categorized under: Translation > Translation Regulation.
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Affiliation(s)
- Graham D Pavitt
- Division Molecular and Cellular Function, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Manchester, UK
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30
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Loughran G, Firth AE, Atkins JF, Ivanov IP. Translational autoregulation of BZW1 and BZW2 expression by modulating the stringency of start codon selection. PLoS One 2018; 13:e0192648. [PMID: 29470543 PMCID: PMC5823381 DOI: 10.1371/journal.pone.0192648] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 01/26/2018] [Indexed: 01/20/2023] Open
Abstract
The efficiency of start codon selection during ribosomal scanning in eukaryotic translation initiation is influenced by the context or flanking nucleotides surrounding the AUG codon. The levels of eukaryotic translation initiation factors 1 (eIF1) and 5 (eIF5) play critical roles in controlling the stringency of translation start site selection. The basic leucine zipper and W2 domain-containing proteins 1 and 2 (BZW1 and BZW2), also known as eIF5-mimic proteins, are paralogous human proteins containing C-terminal HEAT domains that resemble the HEAT domain of eIF5. We show that translation of mRNAs encoding BZW1 and BZW2 homologs in fungi, plants and metazoans is initiated by AUG codons in conserved unfavorable initiation contexts. This conservation is reminiscent of the conserved unfavorable initiation context that enables autoregulation of EIF1. We show that overexpression of BZW1 and BZW2 proteins enhances the stringency of start site selection, and that their poor initiation codons confer autoregulation on BZW1 and BZW2 mRNA translation. We also show that overexpression of these two proteins significantly diminishes the effect of overexpressing eIF5 on stringency of start codon selection, suggesting they antagonize this function of eIF5. These results reveal a surprising role for BZW1 and BZW2 in maintaining homeostatic stringency of start codon selection, and taking into account recent biochemical, genetic and structural insights into eukaryotic initiation, suggest a model for BZW1 and BZW2 function.
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Affiliation(s)
- Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E. Firth
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - John F. Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America
| | - Ivaylo P. Ivanov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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31
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Abstract
Salivary gland cancers (SGCs), categorized as head and neck cancers (HNCs), constitute about 6% of head and neck cancer diagnoses based on estimate by American Head and Neck Society. Salivary gland tumors originate from different glandular cell types and are thus morphologically diverse. These tumors arise from any of the three major and various minor salivary glands. The incidence of SGCs has slowly increased during the last four decades. The etiology of SGCs is mostly unknown; however, specific gene mutations are associated with certain types of salivary tumors. Treatment options include surgical resection, radiation therapy (RT), chemotherapy, and multimodality therapy. HNC patients treated with RT often develop xerostomia and salivary hypofunction due to damaged salivary glands. In this review, we discuss etiology of SGCs, present findings on the role of autophagy in salivary tumorigenesis, review adverse effects of radiation treatment, and examine remedies for restoration of salivary function.
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Affiliation(s)
- H. Helen Lin
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA 91010
| | | | - David K. Ann
- Department of Diabetes and Metabolic Diseases Research, Beckman Research Institute, City of Hope Comprehensive Cancer Center, Duarte, CA 91010
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32
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Tang L, Morris J, Wan J, Moore C, Fujita Y, Gillaspie S, Aube E, Nanda J, Marques M, Jangal M, Anderson A, Cox C, Hiraishi H, Dong L, Saito H, Singh CR, Witcher M, Topisirovic I, Qian SB, Asano K. Competition between translation initiation factor eIF5 and its mimic protein 5MP determines non-AUG initiation rate genome-wide. Nucleic Acids Res 2017; 45:11941-11953. [PMID: 28981728 PMCID: PMC5714202 DOI: 10.1093/nar/gkx808] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2017] [Accepted: 08/31/2017] [Indexed: 12/27/2022] Open
Abstract
In the human genome, translation initiation from non-AUG codons plays an important role in various gene regulation programs. However, mechanisms regulating the non-AUG initiation rate remain poorly understood. Here, we show that the non-AUG initiation rate is nearly consistent under a fixed nucleotide context in various human and insect cells. Yet, it ranges from <1% to nearly 100% compared to AUG translation, depending on surrounding sequences, including Kozak, and possibly additional nucleotide contexts. Mechanistically, this range of non-AUG initiation is controlled in part, by the eIF5-mimic protein (5MP). 5MP represses non-AUG translation by competing with eIF5 for the Met-tRNAi-binding factor eIF2. Consistently, eIF5 increases, whereas 5MP decreases translation of NAT1/EIF4G2/DAP5, whose sole start codon is GUG. By modulating eIF5 and 5MP1 expression in combination with ribosome profiling we identified a handful of previously unknown non-AUG initiation sites, some of which serve as the exclusive start codons. If the initiation rate for these codons is low, then an AUG-initiated downstream ORF prevents the generation of shorter, AUG-initiated isoforms. We propose that the homeostasis of the non-AUG translatome is maintained through balanced expression of eIF5 and 5MP.
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Affiliation(s)
- Leiming Tang
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Jacob Morris
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Ji Wan
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Chelsea Moore
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Yoshihiko Fujita
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Sarah Gillaspie
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Eric Aube
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | - Maud Marques
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Maika Jangal
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Abbey Anderson
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Christian Cox
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Hiroyuki Hiraishi
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Leiming Dong
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Hirohide Saito
- Center for iPS Cell Research and Application, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Michael Witcher
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Ivan Topisirovic
- Lady Davis Institute, and the Gerald Bronfman Department of Oncology, McGill University, Montreal, QC H3A 2B4, Canada
| | - Shu-Bing Qian
- Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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33
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Ali MU, Ur Rahman MS, Jia Z, Jiang C. Eukaryotic translation initiation factors and cancer. Tumour Biol 2017; 39:1010428317709805. [PMID: 28653885 DOI: 10.1177/1010428317709805] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Recent technological advancements have shown tremendous mechanistic accomplishments in our understanding of the mechanism of messenger RNA translation in eukaryotic cells. Eukaryotic messenger RNA translation is very complex process that includes four phases (initiation, elongation, termination, and ribosome recycling) and diverse mechanisms involving protein and non-protein molecules. Translation regulation is principally achieved during initiation step of translation, which is organized by multiple eukaryotic translation initiation factors. Eukaryotic translation initiation factor proteins help in stabilizing the formation of the functional ribosome around the start codon and provide regulatory mechanisms in translation initiation. Dysregulated messenger RNA translation is a common feature of tumorigenesis. Various oncogenic and tumor suppressive genes affect/are affected by the translation machinery, making the components of the translation apparatus promising therapeutic targets for the novel anticancer drug. This review provides details on the role of eukaryotic translation initiation factors in messenger RNA translation initiation, their contribution to onset and progression of tumor, and how dysregulated eukaryotic translation initiation factors can be used as a target to treat carcinogenesis.
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Affiliation(s)
- Muhammad Umar Ali
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Muhammad Saif Ur Rahman
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Zhenyu Jia
- 2 Institute of Occupational Diseases, Zhejiang Academy of Medical Sciences, Hangzhou, China
| | - Cao Jiang
- 1 Clinical Research Center, The Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, China
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34
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Translational control and the cancer cell response to stress. Curr Opin Cell Biol 2017; 45:102-109. [PMID: 28582681 DOI: 10.1016/j.ceb.2017.05.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 04/24/2017] [Accepted: 05/02/2017] [Indexed: 11/24/2022]
Abstract
The evidence for the importance of aberrant translation in cancer cells is overwhelming. Reflecting the wealth of data, there are excellent reviews delineating how ribosomes and initiation factors are linked to cancer [1-3], and the therapeutic strategies being devised to target them [4]. Changes in translational efficiency can engender a malignant phenotype without the need for chromatin reorganization, transcription, splicing and mRNA export [5,6]. Thus, cancer-related modulations of the translational machinery are ideally suited to allow cancer cells to respond to the various stresses encountered along the path of tumorigenesis and organism-wide dissemination [7•,8,9,10•]. Emerging findings supporting this notion are the focus of this review.
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35
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Jennings MD, Kershaw CJ, Adomavicius T, Pavitt GD. Fail-safe control of translation initiation by dissociation of eIF2α phosphorylated ternary complexes. eLife 2017; 6:e24542. [PMID: 28315520 PMCID: PMC5404910 DOI: 10.7554/elife.24542] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/16/2017] [Indexed: 01/21/2023] Open
Abstract
Phosphorylation of eIF2α controls translation initiation by restricting the levels of active eIF2-GTP/Met-tRNAi ternary complexes (TC). This modulates the expression of all eukaryotic mRNAs and contributes to the cellular integrated stress response. Key to controlling the activity of eIF2 are translation factors eIF2B and eIF5, thought to primarily function with eIF2-GDP and TC respectively. Using a steady-state kinetics approach with purified proteins we demonstrate that eIF2B binds to eIF2 with equal affinity irrespective of the presence or absence of competing guanine nucleotides. We show that eIF2B can compete with Met-tRNAi for eIF2-GTP and can destabilize TC. When TC is formed with unphosphorylated eIF2, eIF5 can out-compete eIF2B to stabilize TC/eIF5 complexes. However when TC/eIF5 is formed with phosphorylated eIF2, eIF2B outcompetes eIF5 and destabilizes TC. These data uncover competition between eIF2B and eIF5 for TC and identify that phosphorylated eIF2-GTP translation initiation intermediate complexes can be inhibited by eIF2B.
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Affiliation(s)
- Martin D Jennings
- Division of Molecular and Cellular Function, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Christopher J Kershaw
- Division of Molecular and Cellular Function, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Tomas Adomavicius
- Division of Molecular and Cellular Function, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
| | - Graham D Pavitt
- Division of Molecular and Cellular Function, Faculty of Biology Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, The University of Manchester, Manchester, United Kingdom
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Role of Eukaryotic Initiation Factors during Cellular Stress and Cancer Progression. J Nucleic Acids 2016; 2016:8235121. [PMID: 28083147 PMCID: PMC5204094 DOI: 10.1155/2016/8235121] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Accepted: 11/14/2016] [Indexed: 12/12/2022] Open
Abstract
Protein synthesis can be segmented into distinct phases comprising mRNA translation initiation, elongation, and termination. Translation initiation is a highly regulated and rate-limiting step of protein synthesis that requires more than 12 eukaryotic initiation factors (eIFs). Extensive evidence shows that the transcriptome and corresponding proteome do not invariably correlate with each other in a variety of contexts. In particular, translation of mRNAs specific to angiogenesis, tumor development, and apoptosis is altered during physiological and pathophysiological stress conditions. In cancer cells, the expression and functions of eIFs are hampered, resulting in the inhibition of global translation and enhancement of translation of subsets of mRNAs by alternative mechanisms. A precise understanding of mechanisms involving eukaryotic initiation factors leading to differential protein expression can help us to design better strategies to diagnose and treat cancer. The high spatial and temporal resolution of translation control can have an immediate effect on the microenvironment of the cell in comparison with changes in transcription. The dysregulation of mRNA translation mechanisms is increasingly being exploited as a target to treat cancer. In this review, we will focus on this context by describing both canonical and noncanonical roles of eIFs, which alter mRNA translation.
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