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Weiss B, Dikstein R. Unraveling the landscapes and regulation of scanning, leaky scanning, and 48S initiation complex conformations. Cell Rep 2024; 43:114126. [PMID: 38630588 DOI: 10.1016/j.celrep.2024.114126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 01/19/2024] [Accepted: 04/02/2024] [Indexed: 04/19/2024] Open
Abstract
Scanning and initiation are critical steps in translation. Here, we utilized translation complex profiling (TCP-seq) to investigate 48S organization and eIF4G1-eIF1 inhibition impact. We provide global views of scanning and leaky scanning, uncovering a central role of eIF4G1-eIF1 in their regulation. We confirm AUG context importance, with non-leaky genes featuring a Kozak context and cytosine at positions -1 and +5. Capturing 48S complexes associated with eIF1, eIF4G1, eIF3, and eIF2 through selective TCP-seq revealed that the eIF3-scanning ribosome is highly vulnerable to eIF4G1-eIF1 inhibition, and eIF1 tends to dissociate upon AUG recognition. Initiation-site footprint analysis revealed a class spanning -12 to +18/19 from the AUG, representing the entire 48S and enriched with eIF2, eIF1, and eIF4G1, indicative of early initiation. Another eIF3-dependent class extends up to +26 and exhibits reduced eIF2 and eIF4G1 association, suggesting a late/alternative initiation complex. Our analysis provides an overview of scanning, initiation, and evidence for conformational rearrangements in vivo.
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Affiliation(s)
- Benjamin Weiss
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel.
| | - Rivka Dikstein
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel.
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2
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Liu RH, Xiao XY, Yao L, Jia YY, Guo J, Wang XC, Kong Y, Kong QX. Eukaryotic translation initiation factor EIF4G1 p.Ser637Cys mutation in a family with Parkinson's disease with antecedent essential tremor. Exp Ther Med 2024; 27:206. [PMID: 38590578 PMCID: PMC11000071 DOI: 10.3892/etm.2024.12494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/09/2024] [Indexed: 04/10/2024] Open
Abstract
Essential tremor (ET) and Parkinson's disease (PD) are common chronic movement disorders that can cause a substantial degree of disability. However, the etiology underlying these two conditions remains poorly understood. In the present study, Whole-exome sequencing of peripheral blood samples from the proband and Sanger sequencing of the other 18 family members, and pedigree analysis of four generations of 29 individuals with both ET and PD in a nonconsanguineous Chinese family were performed. Specifically, family members who had available medical information, including historical documentation and physical examination records, were included. A novel c.1909A>T (p.Ser637Cys) missense mutation was identified in the eukaryotic translation initiation factor 4γ1 (EIF4G1) gene as the candidate likely responsible for both conditions. In total, 9 family members exhibited tremor of the bilateral upper limbs and/or head starting from ages of ≥40 years, 3 of whom began showing evidence of PD in their 70s. Eukaryotic initiation factor 4 (eIF4)G1, a component of the translation initiation complex eIF4F, serves as a scaffold protein that interacts with many initiation factors and then binds to the 40S ribosomal subunit. The EIF4G1 (p.Ser637Cys) might inhibit the recruitment of the mRNA to the ribosome. In conclusion, the results from the present study suggested that EIF4G1 may be responsible for the hereditary PD with 'antecedent ET' reported in the family assessed.
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Affiliation(s)
- Rui-Han Liu
- Department of Pediatrics, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China
- College of TCM, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250399, P.R. China
| | - Xiang-Yu Xiao
- Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Lei Yao
- Clinical Medical College, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Yuan-Yuan Jia
- Department of Neurology, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Jia Guo
- Clinical Medical College, Jining Medical University, Jining, Shandong 272000, P.R. China
| | - Xing-Chen Wang
- Cheeloo College of Medicine, Shandong University, Jinan, Shandong 250012, P.R. China
| | - Yu Kong
- Department of Medical Imaging, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China
- College of Materials Science and Engineering, Qingdao University, Qingdao, Shandong 266071, P.R. China
| | - Qing-Xia Kong
- Department of Neurology, Affiliated Hospital of Jining Medical University, Jining, Shandong 272000, P.R. China
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3
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Brito Querido J, Díaz-López I, Ramakrishnan V. The molecular basis of translation initiation and its regulation in eukaryotes. Nat Rev Mol Cell Biol 2024; 25:168-186. [PMID: 38052923 DOI: 10.1038/s41580-023-00624-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2023] [Indexed: 12/07/2023]
Abstract
The regulation of gene expression is fundamental for life. Whereas the role of transcriptional regulation of gene expression has been studied for several decades, it has been clear over the past two decades that post-transcriptional regulation of gene expression, of which translation regulation is a major part, can be equally important. Translation can be divided into four main stages: initiation, elongation, termination and ribosome recycling. Translation is controlled mainly during its initiation, a process which culminates in a ribosome positioned with an initiator tRNA over the start codon and, thus, ready to begin elongation of the protein chain. mRNA translation has emerged as a powerful tool for the development of innovative therapies, yet the detailed mechanisms underlying the complex process of initiation remain unclear. Recent studies in yeast and mammals have started to shed light on some previously unclear aspects of this process. In this Review, we discuss the current state of knowledge on eukaryotic translation initiation and its regulation in health and disease. Specifically, we focus on recent advances in understanding the processes involved in assembling the 43S pre-initiation complex and its recruitment by the cap-binding complex eukaryotic translation initiation factor 4F (eIF4F) at the 5' end of mRNA. In addition, we discuss recent insights into ribosome scanning along the 5' untranslated region of mRNA and selection of the start codon, which culminates in joining of the 60S large subunit and formation of the 80S initiation complex.
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Affiliation(s)
- Jailson Brito Querido
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
- Department of Biological Chemistry, University of Michigan, Ann Arbor, MI, USA
- Life Sciences Institute, University of Michigan, Ann Arbor, MI, USA
| | - Irene Díaz-López
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - V Ramakrishnan
- MRC Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK.
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4
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Chen X, An Y, Tan M, Xie D, Liu L, Xu B. Biological functions and research progress of eIF4E. Front Oncol 2023; 13:1076855. [PMID: 37601696 PMCID: PMC10435865 DOI: 10.3389/fonc.2023.1076855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 01/30/2023] [Indexed: 08/22/2023] Open
Abstract
The eukaryotic translation initiation factor eIF4E can specifically bind to the cap structure of an mRNA 5' end, mainly regulating translation initiation and preferentially enhancing the translation of carcinogenesis related mRNAs. The expression of eIF4E is closely related to a variety of malignant tumors. In tumor cells, eIF4E activity is abnormally increased, which stimulates cell growth, metastasis and translation of related proteins. The main factors affecting eIF4E activity include intranuclear regulation, phosphorylation of 4EBPs, and phosphorylation and sumoylation of eIF4E. In this review, we summarize the biological functions and the research progress of eIF4E, the main influencing factors of eIF4E activity, and the recent progress of drugs targeting eIF4E, in the hope of providing new insights for the treatment of multiple malignancies and development of targeted drugs.
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Affiliation(s)
- Xiaocong Chen
- Department of Clinical Medicine, Fenyang College of Shanxi Medical University, Fenyang, China
| | - Yang An
- Department of Clinical Medicine, Fenyang College of Shanxi Medical University, Fenyang, China
| | - Mengsi Tan
- Department of Clinical Medicine, Fenyang College of Shanxi Medical University, Fenyang, China
| | - Dongrui Xie
- Department of Clinical Medicine, Fenyang College of Shanxi Medical University, Fenyang, China
| | - Ling Liu
- Department of Medical Laboratory Science, Fenyang College of Shanxi Medical University, Fenyang, China
- Key Laboratory of Lvliang for Clinical Molecular Diagnostics, Fenyang, China
- Department of Clinical Laboratory, Fenyang Hospital of Shanxi Province, Fenyang, China
| | - Benjin Xu
- Department of Medical Laboratory Science, Fenyang College of Shanxi Medical University, Fenyang, China
- Key Laboratory of Lvliang for Clinical Molecular Diagnostics, Fenyang, China
- Department of Clinical Laboratory, Fenyang Hospital of Shanxi Province, Fenyang, China
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5
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Kamble VS, Pachpor TA, Khandagale SB, Wagh VV, Khare SP. Translation initiation and dysregulation of initiation factors in rare diseases. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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6
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Lai G, Zhong X, Liu H, Deng J, Li K, Xie B. A Novel m7G-Related Genes-Based Signature with Prognostic Value and Predictive Ability to Select Patients Responsive to Personalized Treatment Strategies in Bladder Cancer. Cancers (Basel) 2022; 14:5346. [PMID: 36358764 PMCID: PMC9656096 DOI: 10.3390/cancers14215346] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 09/08/2023] Open
Abstract
Although N7-methylguanosine (m7G) modification serves as a tumor promoter in bladder cancer (BLCA), the comprehensive role of m7G-related characterization in BLCA remains unclear. In this study, we systematically evaluated the m7G-related clusters of 760 BLCA patients through consensus unsupervised clustering analysis. Next, we investigated the underlying m7G-related genes among these m7G-related clusters. Univariate Cox and LASSO regressions were used for screening out prognostic genes and for reducing the dimension, respectively. Finally, we developed a novel m7G-related scoring system via the GSVA algorithm. The correlation between tumor microenvironment, prediction of personalized therapies and this m7G-related signature was gradually revealed. We first identified three m7G-related clusters and 1108 differentially expressed genes relevant to the three clusters. Based on the profile of 1108 genes, we divided BLCA patients into two clusters, which were quantified by our established m7G-related scoring system. Patients with higher m7G-related scores tended to have a better OS and more chances to benefit from immunotherapy. A significantly negative connection between sensitivity to classic chemotherapeutic drugs and m7G-related signature was uncovered. In summary, our data show that m7G-related characterization of BLCA patients can be of value for prognostic stratification and for patient-oriented therapeutic options, designing personalized treatment strategies in the preclinical setting.
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Affiliation(s)
| | - Xiaoni Zhong
- Department of Epidemiology and Health Statistics, School of Public Health, Chongqing Medical University, Yixue Road, Chongqing 400016, China
| | | | | | | | - Biao Xie
- Department of Epidemiology and Health Statistics, School of Public Health, Chongqing Medical University, Yixue Road, Chongqing 400016, China
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7
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Sehrawat U, Haimov O, Weiss B, Tamarkin-Ben Harush A, Ashkenazi S, Plotnikov A, Noiman T, Leshkowitz D, Stelzer G, Dikstein R. Inhibitors of eIF4G1-eIF1 uncover its regulatory role of ER/UPR stress-response genes independent of eIF2α-phosphorylation. Proc Natl Acad Sci U S A 2022; 119:e2120339119. [PMID: 35857873 PMCID: PMC9335335 DOI: 10.1073/pnas.2120339119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Accepted: 05/27/2022] [Indexed: 01/22/2023] Open
Abstract
During translation initiation, eIF4G1 dynamically interacts with eIF4E and eIF1. While the role of eIF4E-eIF4G1 is well established, the regulatory functions of eIF4G1-eIF1 are poorly understood. Here, we report the identification of the eIF4G1-eIF1 inhibitors i14G1-10 and i14G1-12. i14G1s directly bind eIF4G1 and inhibit translation in vitro and in the cell, and their effects on translation are dependent on eIF4G1 levels. Translatome analyses revealed that i14G1s mimic eIF1 and eIF4G1 perturbations on the stringency of start codon selection and the opposing roles of eIF1-eIF4G1 in scanning-dependent and scanning-independent short 5' untranslated region (UTR) translation. Remarkably, i14G1s activate ER/unfolded protein response (UPR) stress-response genes via enhanced ribosome loading, elevated 5'UTR translation at near-cognate AUGs, and unexpected concomitant up-regulation of coding-region translation. These effects are, at least in part, independent of eIF2α-phosphorylation. Interestingly, eIF4G1-eIF1 interaction itself is negatively regulated by ER stress and mTOR inhibition. Thus, i14G1s uncover an unknown mechanism of ER/UPR translational stress response and are valuable research tools and potential drugs against diseases exhibiting dysregulated translation.
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Affiliation(s)
- Urmila Sehrawat
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ora Haimov
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Benjamin Weiss
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ana Tamarkin-Ben Harush
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Shaked Ashkenazi
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Alexander Plotnikov
- The Nancy and Stephen Grand Israel National Center for Personalized Medicine, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Tzahi Noiman
- Department of Molecular Genetics, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Dena Leshkowitz
- Department of Life Sciences Core Facilities, Bioinformatics Unit, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Gil Stelzer
- Department of Life Sciences Core Facilities, Bioinformatics Unit, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Rivka Dikstein
- Department of Biomolecular Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel
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8
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Gao Y, Wu D, Chen B, Chen Y, Zhang Q, Zhao P. Rare Variants in Novel Candidate Genes Associated With Nonsyndromic Patent Ductus Arteriosus Identified With Whole-Exome Sequencing. Front Genet 2022; 13:921925. [PMID: 35734438 PMCID: PMC9207465 DOI: 10.3389/fgene.2022.921925] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/09/2022] [Indexed: 11/18/2022] Open
Abstract
Background: Patent ductus arteriosus (PDA) is one of the most common congenital heart defects causing pulmonary hypertension, infective endocarditis, and even death. The important role of genetics in determining spontaneous ductal closure has been well-established. However, as many of the identified variants are rare, thorough identification of the associated genetic factors is necessary to further explore the genetic etiology of PDA. Methods: We performed whole-exome sequencing (WES) on 39 isolated nonsyndromic PDA patients and 100 healthy controls. Rare variants and novel genes were identified through bioinformatic filtering strategies. The expression patterns of candidate genes were explored in human embryo heart samples. Results: Eighteen rare damaging variants of six novel PDA-associated genes (SOX8, NES, CDH2, ANK3, EIF4G1, and HIPK1) were newly identified, which were highly expressed in human embryo hearts. Conclusions: WES is an efficient diagnostic tool for exploring the genetic pathogenesis of PDA. These findings contribute new insights into the molecular basis of PDA and may inform further studies on genetic risk factors for congenital heart defects.
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Affiliation(s)
- Ying Gao
- Department of Pediatric, Shidong Hospital, Shanghai, China
| | - Dan Wu
- Department of Pediatric, Shidong Hospital, Shanghai, China
| | - Bo Chen
- Department of Cardiothoracic Surgery, School of Medicine, Heart Center, Shanghai Children’s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yinghui Chen
- Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qi Zhang
- Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Pengjun Zhao
- Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
- *Correspondence: Pengjun Zhao,
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9
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Nsengimana B, Khan FA, Ngowi EE, Zhou X, Jin Y, Jia Y, Wei W, Ji S. Processing body (P-body) and its mediators in cancer. Mol Cell Biochem 2022; 477:1217-1238. [PMID: 35089528 DOI: 10.1007/s11010-022-04359-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 01/11/2022] [Indexed: 12/24/2022]
Abstract
In recent years, processing bodies (P-bodies) formed by liquid-liquid phase separation, have attracted growing scientific attention due to their involvement in numerous cellular activities, including the regulation of mRNAs decay or storage. These cytoplasmic dynamic membraneless granules contain mRNA storage and decay components such as deadenylase and decapping factors. In addition, different mRNA metabolic regulators, including m6A readers and gene-mediated miRNA-silencing, are also associated with such P-bodies. Cancerous cells may profit from these mRNA decay shredders by up-regulating the expression level of oncogenes and down-regulating tumor suppressor genes. The main challenges of cancer treatment are drug resistance, metastasis, and cancer relapse likely associated with cancer stem cells, heterogeneity, and plasticity features of different tumors. The mRNA metabolic regulators based on P-bodies play a great role in cancer development and progression. The dysregulation of P-bodies mediators affects mRNA metabolism. However, less is known about the relationship between P-bodies mediators and cancerous behavior. The current review summarizes the recent studies on P-bodies mediators, their contribution to tumor development, and their potential in the clinical setting, particularly highlighting the P-bodies as potential drug-carriers such as exosomes to anticancer in the future.
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Affiliation(s)
- Bernard Nsengimana
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China
| | - Faiz Ali Khan
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China
| | - Ebenezeri Erasto Ngowi
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China
| | - Xuefeng Zhou
- Department of Oncology, Dongtai Affiliated Hospital of Nantong University, Dongtai, 224200, Jiangsu, People's Republic of China
| | - Yu Jin
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China
| | - Yuting Jia
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China
| | - Wenqiang Wei
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China.
| | - Shaoping Ji
- Laboratory of Cell Signal Transduction, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Henan University, Henan, 475004, People's Republic of China.
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10
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Bi-directional ribosome scanning controls the stringency of start codon selection. Nat Commun 2021; 12:6604. [PMID: 34782646 PMCID: PMC8593136 DOI: 10.1038/s41467-021-26923-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Accepted: 10/28/2021] [Indexed: 11/29/2022] Open
Abstract
The fidelity of start codon recognition by ribosomes is paramount during protein synthesis. The current knowledge of eukaryotic translation initiation implies unidirectional 5'→3' migration of the pre-initiation complex (PIC) along the 5' UTR. In probing translation initiation from ultra-short 5' UTR, we report that an AUG triplet near the 5' end can be selected via PIC backsliding. Bi-directional ribosome scanning is supported by competitive selection of closely spaced AUG codons and recognition of two initiation sites flanking an internal ribosome entry site. Transcriptome-wide PIC profiling reveals footprints with an oscillation pattern near the 5' end and start codons. Depleting the RNA helicase eIF4A leads to reduced PIC oscillations and impaired selection of 5' end start codons. Enhancing the ATPase activity of eIF4A promotes nonlinear PIC scanning and stimulates upstream translation initiation. The helicase-mediated PIC conformational switch may provide an operational mechanism that unifies ribosome recruitment, scanning, and start codon selection.
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11
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Gueiderikh A, Maczkowiak-Chartois F, Rouvet G, Souquère-Besse S, Apcher S, Diaz JJ, Rosselli F. Fanconi anemia A protein participates in nucleolar homeostasis maintenance and ribosome biogenesis. SCIENCE ADVANCES 2021; 7:7/1/eabb5414. [PMID: 33523834 PMCID: PMC7775781 DOI: 10.1126/sciadv.abb5414] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 10/28/2020] [Indexed: 05/22/2023]
Abstract
Fanconi anemia (FA), the most common inherited bone marrow failure and leukemia predisposition syndrome, is generally attributed to alterations in DNA damage responses due to the loss of function of the DNA repair and replication rescue activities of the FANC pathway. Here, we report that FANCA deficiency, whose inactivation has been identified in two-thirds of FA patients, is associated with nucleolar homeostasis loss, mislocalization of key nucleolar proteins, including nucleolin (NCL) and nucleophosmin 1 (NPM1), as well as alterations in ribosome biogenesis and protein synthesis. FANCA coimmunoprecipitates with NCL and NPM1 in a FANCcore complex-independent manner and, unique among the FANCcore complex proteins, associates with ribosomal subunits, influencing the stoichiometry of the translational machineries. In conclusion, we have identified unexpected nucleolar and translational consequences specifically associated with FANCA deficiency that appears to be involved in both DNA damage and nucleolar stress responses, challenging current hypothesis on FA physiopathology.
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Affiliation(s)
- Anna Gueiderikh
- CNRS-UMR9019, Équipe labellisée "La Ligue contre le Cancer," 94805 Villejuif, France
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
| | - Frédérique Maczkowiak-Chartois
- CNRS-UMR9019, Équipe labellisée "La Ligue contre le Cancer," 94805 Villejuif, France
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
| | - Guillaume Rouvet
- CNRS-UMR9019, Équipe labellisée "La Ligue contre le Cancer," 94805 Villejuif, France
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
| | - Sylvie Souquère-Besse
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
- CNRS-UMS3655, 94805 Villejuif, France
| | - Sébastien Apcher
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
- INSERM-UMR1015, 94805 Villejuif, France
| | - Jean-Jacques Diaz
- Université Lyon, Université Claude Bernard Lyon 1, Inserm 1052, CNRS 5286, Centre Léon Bérard, Cancer Research Center of Lyon, 69373 Lyon cedex 08, France
| | - Filippo Rosselli
- CNRS-UMR9019, Équipe labellisée "La Ligue contre le Cancer," 94805 Villejuif, France.
- Gustave Roussy Cancer Center, 94805 Villejuif, France
- Université Paris-Saclay-Paris Sud, Orsay, France
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12
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Jo S, Lockridge A, Mohan R, Esch N, Schlichting R, Panigrahy N, Essawy A, Gustafson E, Alejandro EU. Translational Factor eIF4G1 Regulates Glucose Homeostasis and Pancreatic β-Cell Function. Diabetes 2021; 70:155-170. [PMID: 33115825 PMCID: PMC7881850 DOI: 10.2337/db20-0057] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 10/18/2020] [Indexed: 12/27/2022]
Abstract
Protein translation is essential for cell physiology, and dysregulation of this process has been linked to aging-related diseases such as type 2 diabetes. Reduced protein level of a requisite scaffolding protein of the initiation complex, eIF4G1, downstream of nutrients and insulin signaling is associated with diabetes in humans and mice. In the current study, we tested the hypothesis that eIF4G1 is critical for β-cell function and glucose homeostasis by genetically ablating eIF4G1 specifically in β-cells in vivo (βeIF4G1 knockout [KO]). Adult male and female βeIF4G1KO mice displayed glucose intolerance but normal insulin sensitivity. β-Cell mass was normal under steady state and under metabolic stress by diet-induced obesity, but we observed increases in proliferation and apoptosis in β-cells of βeIF4G1KO. We uncovered deficits in insulin secretion, partly due to reduced mitochondrial oxygen consumption rate, glucose-stimulated Ca2+ flux, and reduced insulin content associated with loss of eIF4E, the mRNA 5' cap-binding protein of the initiation complex and binding partner of eIF4G1. Genetic reconstitution of eIF4E in single β-cells or intact islets of βeIF4G1KO mice recovers insulin content, implicating an unexplored role for eIF4G1/eIF4E in insulin biosynthesis. Altogether these data demonstrate an essential role for the translational factor eIF4G1 on glucose homeostasis and β-cell function.
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Affiliation(s)
- Seokwon Jo
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Amber Lockridge
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Ramkumar Mohan
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Nicholas Esch
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Regina Schlichting
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Neha Panigrahy
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Ahmad Essawy
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Eric Gustafson
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
| | - Emilyn U Alejandro
- Department of Integrative Biology and Physiology, University of Minnesota Medical School, Minneapolis, MN
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Chikashige Y, Kato H, Thornton M, Pepper W, Hilgers M, Cecil A, Asano I, Yamada H, Mori C, Brunkow C, Moravek C, Urano T, Singh CR, Asano K. Gcn2 eIF2α kinase mediates combinatorial translational regulation through nucleotide motifs and uORFs in target mRNAs. Nucleic Acids Res 2020; 48:8977-8992. [PMID: 32710633 PMCID: PMC7498311 DOI: 10.1093/nar/gkaa608] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 07/06/2020] [Accepted: 07/24/2020] [Indexed: 12/14/2022] Open
Abstract
The protein kinase Gcn2 is a central transducer of nutritional stress signaling important for stress adaptation by normal cells and the survival of cancer cells. In response to nutrient deprivation, Gcn2 phosphorylates eIF2α, thereby repressing general translation while enhancing translation of specific mRNAs with upstream ORFs (uORFs) situated in their 5'-leader regions. Here we performed genome-wide measurements of mRNA translation during histidine starvation in fission yeast Schizosaccharomyces pombe. Polysome analyses were combined with microarray measurements to identify gene transcripts whose translation was up-regulated in response to the stress in a Gcn2-dependent manner. We determined that translation is reprogrammed to enhance RNA metabolism and chromatin regulation and repress ribosome synthesis. Interestingly, translation of intron-containing mRNAs was up-regulated. The products of the regulated genes include additional eIF2α kinase Hri2 amplifying the stress signaling and Gcn5 histone acetyl transferase and transcription factors, together altering genome-wide transcription. Unique dipeptide-coding uORFs and nucleotide motifs, such as '5'-UGA(C/G)GG-3', are found in 5' leader regions of regulated genes and shown to be responsible for translational control.
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Affiliation(s)
- Yuji Chikashige
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Hiroaki Kato
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Mackenzie Thornton
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Whitney Pepper
- 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
| | - Ariana Cecil
- 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
| | - Haana Yamada
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
- Department of Advanced Transdisciplinary Sciences, Faculty of Advanced Life Science, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan
| | - Chie Mori
- Advanced ICT Research Institute, National Institute of Information and Communications Technology, Kobe, Hyogo 651-2492, Japan
| | - Cheyenne Brunkow
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Carter Moravek
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Takeshi Urano
- Department of Biochemistry, Shimane University School of Medicine, Izumo, Shimane 693-8501, Japan
| | - Chingakham Ranjit Singh
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | - Katsura Asano
- Molecular Cellular and Developmental Biology Program, Division of Biology, Kansas State University, Manhattan, KS 66506, USA
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Slobodin B, Dikstein R. So close, no matter how far: multiple paths connecting transcription to mRNA translation in eukaryotes. EMBO Rep 2020; 21:e50799. [PMID: 32803873 PMCID: PMC7507372 DOI: 10.15252/embr.202050799] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/22/2020] [Accepted: 07/23/2020] [Indexed: 12/15/2022] Open
Abstract
Transcription of DNA into mRNA and translation of mRNA into proteins are two major processes underlying gene expression. Due to the distinct molecular mechanisms, timings, and locales of action, these processes are mainly considered to be independent. During the last two decades, however, multiple factors and elements were shown to coordinate transcription and translation, suggesting an intricate level of synchronization. This review discusses the molecular mechanisms that impact both processes in eukaryotic cells of different origins. The emerging global picture suggests evolutionarily conserved regulation and coordination between transcription and mRNA translation, indicating the importance of this phenomenon for the fine-tuning of gene expression and the adjustment to constantly changing conditions.
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Affiliation(s)
- Boris Slobodin
- Department of Biomolecular SciencesThe Weizmann Institute of ScienceRehovotIsrael
| | - Rivka Dikstein
- Department of Biomolecular SciencesThe Weizmann Institute of ScienceRehovotIsrael
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Messenger RNAs with large numbers of upstream open reading frames are translated via leaky scanning and reinitiation in the asexual stages of Plasmodium falciparum. Parasitology 2020; 147:1100-1113. [DOI: 10.1017/s0031182020000840] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
AbstractThe genome of Plasmodium falciparum has one of the most skewed base-pair compositions of any eukaryote, with an AT content of 80–90%. As start and stop codons are AT-rich, the probability of finding upstream open reading frames (uORFs) in messenger RNAs (mRNAs) is high and parasite mRNAs have an average of 11 uORFs in their leader sequences. Similar to other eukaryotes, uORFs repress the translation of the downstream open reading frame (dORF) in P. falciparum, yet the parasite translation machinery is able to bypass these uORFs and reach the dORF to initiate translation. This can happen by leaky scanning and/or reinitiation.In this report, we assessed leaky scanning and reinitiation by studying the effect of uORFs on the translation of a dORF, in this case, the luciferase reporter gene, and showed that both mechanisms are employed in the asexual blood stages of P. falciparum. Furthermore, in addition to the codon usage of the uORF, translation of the dORF is governed by the Kozak sequence and length of the uORF, and inter-cistronic distance between the uORF and dORF. Based on these features whole-genome data was analysed to uncover classes of genes that might be regulated by uORFs. This study indicates that leaky scanning and reinitiation appear to be widespread in asexual stages of P. falciparum, which may require modifications of existing factors that are involved in translation initiation in addition to novel, parasite-specific proteins.
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Janapala Y, Preiss T, Shirokikh NE. Control of Translation at the Initiation Phase During Glucose Starvation in Yeast. Int J Mol Sci 2019; 20:E4043. [PMID: 31430885 PMCID: PMC6720308 DOI: 10.3390/ijms20164043] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 08/10/2019] [Accepted: 08/15/2019] [Indexed: 12/13/2022] Open
Abstract
Glucose is one of the most important sources of carbon across all life. Glucose starvation is a key stress relevant to all eukaryotic cells. Glucose starvation responses have important implications in diseases, such as diabetes and cancer. In yeast, glucose starvation causes rapid and dramatic effects on the synthesis of proteins (mRNA translation). Response to glucose deficiency targets the initiation phase of translation by different mechanisms and with diverse dynamics. Concomitantly, translationally repressed mRNAs and components of the protein synthesis machinery may enter a variety of cytoplasmic foci, which also form with variable kinetics and may store or degrade mRNA. Much progress has been made in understanding these processes in the last decade, including with the use of high-throughput/omics methods of RNA and RNA:protein detection. This review dissects the current knowledge of yeast reactions to glucose starvation systematized by the stage of translation initiation, with the focus on rapid responses. We provide parallels to mechanisms found in higher eukaryotes, such as metazoans, for the most critical responses, and point out major remaining gaps in knowledge and possible future directions of research on translational responses to glucose starvation.
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Affiliation(s)
- Yoshika Janapala
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Preiss
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.
| | - Nikolay E Shirokikh
- EMBL-Australia Collaborating Group, Department of Genome Sciences, The John Curtin School of Medical Research, The Australian National University, Canberra, ACT 2601, Australia.
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