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Mahé M, Rios-Fuller T, Katsara O, Schneider RJ. Non-canonical mRNA translation initiation in cell stress and cancer. NAR Cancer 2024; 6:zcae026. [PMID: 38828390 PMCID: PMC11140632 DOI: 10.1093/narcan/zcae026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/08/2024] [Accepted: 05/29/2024] [Indexed: 06/05/2024] Open
Abstract
The now well described canonical mRNA translation initiation mechanism of m7G 'cap' recognition by cap-binding protein eIF4E and assembly of the canonical pre-initiation complex consisting of scaffolding protein eIF4G and RNA helicase eIF4A has historically been thought to describe all cellular mRNA translation. However, the past decade has seen the discovery of alternative mechanisms to canonical eIF4E mediated mRNA translation initiation. Studies have shown that non-canonical alternate mechanisms of cellular mRNA translation initiation, whether cap-dependent or independent, serve to provide selective translation of mRNAs under cell physiological and pathological stress conditions. These conditions typically involve the global downregulation of canonical eIF4E1/cap-mediated mRNA translation, and selective translational reprogramming of the cell proteome, as occurs in tumor development and malignant progression. Cancer cells must be able to maintain physiological plasticity to acquire a migratory phenotype, invade tissues, metastasize, survive and adapt to severe microenvironmental stress conditions that involve inhibition of canonical mRNA translation initiation. In this review we describe the emerging, important role of non-canonical, alternate mechanisms of mRNA translation initiation in cancer, particularly in adaptation to stresses and the phenotypic cell fate changes involved in malignant progression and metastasis. These alternate translation initiation mechanisms provide new targets for oncology therapeutics development.
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Affiliation(s)
- Mélanie Mahé
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Tiffany Rios-Fuller
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Olga Katsara
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Robert J Schneider
- Department of Microbiology, NYU Grossman School of Medicine, New York, NY 10016, USA
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2
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Zeng J, Lu C, Huang X, Li Y. The human eIF4E:4E-BP2 complex structure for studying hyperphosphorylation. Phys Chem Chem Phys 2024; 26:10660-10672. [PMID: 38511550 DOI: 10.1039/d3cp05736d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
The cap-dependent mRNA translation is dysregulated in many kinds of cancers. The interaction between eIF4E and eIF4G through a canonical eIF4E-binding motif (CEBM) determines the efficacy of the cap-dependent mRNA translation. eIF4E-binding proteins (4E-BPs) share the CEBM and compete with eIF4G for the same binding surface of eIF4E and then inhibit the mRNA translation. 4E-BPs function as tumor repressors in nature. Hyperphosphorylation of 4E-BPs regulates the structure folding and causes the dissociation of 4E-BPs from eIF4E. However, until now, there has been no structure of the full-length 4E-BPs in complex with eIF4E. The regulation mechanism of phosphorylation is still unclear. In this work, we first investigate the interactions of human eIF4E with the CEBM and an auxiliary eIF4E-binding motif (AEBM) in eIF4G and 4E-BPs. The results unravel that the structure and interactions of the CEBM are highly conserved between eIF4G and 4E-BPs. However, the extended CEBM (ECEBM) in 4E-BPs forms a longer helix than that in eIF4G. The residue R62 in the ECEBM of 4E-BP2 forms salt bridges with E32 and E70 of eIF4E. The residue R63 of 4E-BP2 forms two special hydrogen bonds with N77 of eIF4E. Both of these interactions are missing in eIF4G. The AEBM of 4E-BPs folds into a β-sheet conformation, which protects V81 inside a hydrophobic core in 4E-BP2. In eIF4G, the AEBM exists in a random coil state. The hydrophilic residues S637 and D638 of eIF4G open the hydrophobic core for solvents. The results show that the ECEBM and AEBM may be responsible for the competing advantage of 4E-BP2. Finally, based on our previous work (J. Zeng, F. Jiang and Y. D. Wu, J. Chem. Theory Comput., 2017, 13, 320), the human eIF4E:4E-BP2 complex (eIF4E:BP2P18-I88) including all reported phosphorylation sites is predicted. The eIF4E:BP2P18-I88 complex is different from the existing experimental eIF4E:eIF4G complex and provides an important structure for further studying the regulation mechanism of phosphorylation in 4E-BPs.
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Affiliation(s)
- Juan Zeng
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China.
| | - CuiMin Lu
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China.
| | - Xuan Huang
- School of Biomedical Engineering, Guangdong Medical University, Dongguan 523808, China.
| | - Yang Li
- Department of Urology, Huaihe Hospital of Henan University, Kaifeng 475000, Henan, China.
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3
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Apostolopoulos A, Kawamoto N, Chow SYA, Tsuiji H, Ikeuchi Y, Shichino Y, Iwasaki S. dCas13-mediated translational repression for accurate gene silencing in mammalian cells. Nat Commun 2024; 15:2205. [PMID: 38467613 PMCID: PMC10928199 DOI: 10.1038/s41467-024-46412-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Accepted: 02/27/2024] [Indexed: 03/13/2024] Open
Abstract
Current gene silencing tools based on RNA interference (RNAi) or, more recently, clustered regularly interspaced short palindromic repeats (CRISPR)‒Cas13 systems have critical drawbacks, such as off-target effects (RNAi) or collateral mRNA cleavage (CRISPR‒Cas13). Thus, a more specific method of gene knockdown is needed. Here, we develop CRISPRδ, an approach for translational silencing, harnessing catalytically inactive Cas13 proteins (dCas13). Owing to its tight association with mRNA, dCas13 serves as a physical roadblock for scanning ribosomes during translation initiation and does not affect mRNA stability. Guide RNAs covering the start codon lead to the highest efficacy regardless of the translation initiation mechanism: cap-dependent, internal ribosome entry site (IRES)-dependent, or repeat-associated non-AUG (RAN) translation. Strikingly, genome-wide ribosome profiling reveals the ultrahigh gene silencing specificity of CRISPRδ. Moreover, the fusion of a translational repressor to dCas13 further improves the performance. Our method provides a framework for translational repression-based gene silencing in eukaryotes.
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Grants
- JP20H05784 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05278 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP21H05734 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H04268 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP20H05786 Ministry of Education, Culture, Sports, Science and Technology (MEXT)
- JP23H02415 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20K07016 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23K05648 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP21K15023 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP23KJ2175 MEXT | Japan Society for the Promotion of Science (JSPS)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005h0001 Japan Agency for Medical Research and Development (AMED)
- JP23gm6910005 Japan Agency for Medical Research and Development (AMED)
- JP20gm1410001 Japan Agency for Medical Research and Development (AMED)
- Pioneering Projects MEXT | RIKEN
- Pioneering Projects MEXT | RIKEN
- Exploratory Research Center on Life and Living Systems (ExCELLS), 23EX601
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Affiliation(s)
- Antonios Apostolopoulos
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Naohiro Kawamoto
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Siu Yu A Chow
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hitomi Tsuiji
- Education and Research Division of Pharmacy, School of Pharmacy, Aichi Gakuin University, Nagoya, Aichi, 464-8650, Japan
| | - Yoshiho Ikeuchi
- Institute of Industrial Science, The University of Tokyo, Meguro-ku, Tokyo, 153-8505, Japan
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
- Institute for AI and Beyond, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
| | - Shintaro Iwasaki
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan.
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan.
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4
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Liu P, Yu S, Zheng W, Zhang Q, Qiao J, Li Z, Deng Z, Zhang H. Identification and functional verification of Y-chromosome-specific gene typo-gyf in Bactrocera dorsalis. INSECT SCIENCE 2024. [PMID: 38189161 DOI: 10.1111/1744-7917.13311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 01/09/2024]
Abstract
Genes on the Y chromosome play important roles in male sex determination and development. The identification of Y-chromosome-specific genes not only provides a theoretical basis for the study of male reproductive development, but also offers genetic control targets for agricultural pests. However, Y-chromosome genes are rarely characterized due to their high repeatability and high heterochromatinization, especially in the oriental fruit fly. In this study, 1 011 Y-chromosome-specific candidate sequences were screened from 2 to 4 h Bactrocera dorsalis embryo datasets with the chromosome quotient method, 6 of which were identified as Y-chromosome-specific sequences by polymerase chain reaction, including typo-gyf, a 19 126-bp DNA sequence containing a 575-amino acid open reading frame. Testicular deformation and a significant reduction in sperm number were observed after typo-gyf knockdown with RNA interference in embryos. After typo-gyf knockout with clustered regularly interspaced palindromic repeats (CRISPR) / CRISPR-associated protein 9 in the embryonic stage, the sex ratio of the emergent adults was unbalanced, with far more females than males. A genotype analysis of these females with the Y-chromosome gene MoY revealed no sex reversal. Typo-gyf knockout led to the death of XY individuals in the embryonic stage. We conclude that typo-gyf is an essential gene for male survival, and is also involved in testicular development and spermatogenesis. The identification of typo-gyf and its functional verification provide insight into the roles of Y-chromosome genes in male development.
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Affiliation(s)
- Peipei Liu
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shuning Yu
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Wenping Zheng
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Qiuyuan Zhang
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Jiao Qiao
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Ziniu Li
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Zhurong Deng
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Hongyu Zhang
- National Key Laboratory for Germplasm Innovation and Utilization for Fruit and Vegetable Horticultural Crops, Hubei Hongshan Laboratory, China-Australia Joint Research Centre for Horticultural and Urban Pests, Institute of Urban and Horticultural Entomology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, China
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5
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Barrington CL, Galindo G, Koch AL, Horton ER, Morrison EJ, Tisa S, Stasevich TJ, Rissland OS. Synonymous codon usage regulates translation initiation. Cell Rep 2023; 42:113413. [PMID: 38096059 PMCID: PMC10790568 DOI: 10.1016/j.celrep.2023.113413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Revised: 08/30/2023] [Accepted: 10/25/2023] [Indexed: 12/30/2023] Open
Abstract
Nonoptimal synonymous codons repress gene expression, but the underlying mechanisms are poorly understood. We and others have previously shown that nonoptimal codons slow translation elongation speeds and thereby trigger messenger RNA (mRNA) degradation. Nevertheless, transcript levels are often insufficient to explain protein levels, suggesting additional mechanisms by which codon usage regulates gene expression. Using reporters in human and Drosophila cells, we find that transcript levels account for less than half of the variation in protein abundance due to codon usage. This discrepancy is explained by translational differences whereby nonoptimal codons repress translation initiation. Nonoptimal transcripts are also less bound by the translation initiation factors eIF4E and eIF4G1, providing a mechanistic explanation for their reduced initiation rates. Importantly, translational repression can occur without mRNA decay and deadenylation, and it does not depend on the known nonoptimality sensor, CNOT3. Our results reveal a potent mechanism of regulation by codon usage where nonoptimal codons repress further rounds of translation.
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Affiliation(s)
- Chloe L Barrington
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Gabriel Galindo
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Amanda L Koch
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Emma R Horton
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Evan J Morrison
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Samantha Tisa
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Timothy J Stasevich
- Department of Biochemistry & Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Olivia S Rissland
- Department of Biochemistry & Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA; RNA Bioscience Initiative, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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6
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Hernández G, Vazquez-Pianzola P. eIF4E as a molecular wildcard in metazoans RNA metabolism. Biol Rev Camb Philos Soc 2023; 98:2284-2306. [PMID: 37553111 DOI: 10.1111/brv.13005] [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: 02/09/2023] [Revised: 07/01/2023] [Accepted: 07/25/2023] [Indexed: 08/10/2023]
Abstract
The evolutionary origin of eukaryotes spurred the transition from prokaryotic-like translation to a more sophisticated, eukaryotic translation. During this process, successive gene duplication of a single, primordial eIF4E gene encoding the mRNA cap-binding protein eukaryotic translation initiation factor 4E (eIF4E) gave rise to a plethora of paralog genes across eukaryotes that underwent further functional diversification in RNA metabolism. The ability to take different roles is due to eIF4E promiscuity in binding many partner proteins, rendering eIF4E a highly versatile and multifunctional player that functions as a molecular wildcard. Thus, in metazoans, eIF4E paralogs are involved in various processes, including messenger RNA (mRNA) processing, export, translation, storage, and decay. Moreover, some paralogs display differential expression in tissues and developmental stages and show variable biochemical properties. In this review, we discuss recent advances shedding light on the functional diversification of eIF4E in metazoans. We emphasise humans and two phylogenetically distant species which have become paradigms for studies on development, namely the fruit fly Drosophila melanogaster and the roundworm Caenorhabditis elegans.
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Affiliation(s)
- Greco Hernández
- mRNA and Cancer Laboratory, Unit of Biomedical Research on Cancer, National Institute of Cancer (Instituto Nacional de Cancerología, INCan), 22 San Fernando Ave., Tlalpan, Mexico City, 14080, Mexico
| | - Paula Vazquez-Pianzola
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, Berne, 3012, Switzerland
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7
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Ding Z, Huang G, Wang T, Duan W, Li H, Wang Y, Jia H, Yang Z, Wang K, Chu X, Kurtz-Nelson EC, Ahlers K, Earl RK, Han Y, Feliciano P, Chung WK, Eichler EE, Jiang M, Xiong B. Genetic Ablation of GIGYF1, Associated With Autism, Causes Behavioral and Neurodevelopmental Defects in Zebrafish and Mice. Biol Psychiatry 2023; 94:769-779. [PMID: 36924980 PMCID: PMC10502190 DOI: 10.1016/j.biopsych.2023.02.993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 02/01/2023] [Accepted: 02/16/2023] [Indexed: 03/18/2023]
Abstract
BACKGROUND Autism spectrum disorder is characterized by deficits in social communication and restricted or repetitive behaviors. Due to the extremely high genetic and phenotypic heterogeneity, it is critical to pinpoint the genetic factors for understanding the pathology of these disorders. METHODS We analyzed the exomes generated by the SPARK (Simons Powering Autism Research) project and performed a meta-analysis with previous data. We then generated 1 zebrafish knockout model and 3 mouse knockout models to examine the function of GIGYF1 in neurodevelopment and behavior. Finally, we performed whole tissue and single-nucleus transcriptome analysis to explore the molecular and cellular function of GIGYF1. RESULTS GIGYF1 variants are significantly associated with various neurodevelopmental disorder phenotypes, including autism, global developmental delay, intellectual disability, and sleep disturbance. Loss of GIGYF1 causes similar behavioral effects in zebrafish and mice, including elevated levels of anxiety and reduced social engagement, which is reminiscent of the behavioral deficits in human patients carrying GIGYF1 variants. Moreover, excitatory neuron-specific Gigyf1 knockout mice recapitulate the increased repetitive behaviors and impaired social memory, suggesting a crucial role of Gigyf1 in excitatory neurons, which correlates with the observations in single-nucleus RNA sequencing. We also identified a series of downstream target genes of GIGYF1 that affect many aspects of the nervous system, especially synaptic transmission. CONCLUSIONS De novo variants of GIGYF1 are associated with neurodevelopmental disorders, including autism spectrum disorder. GIGYF1 is involved in neurodevelopment and animal behavior, potentially through regulating hippocampal CA2 neuronal numbers and disturbing synaptic transmission.
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Affiliation(s)
- Zijiao Ding
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Department of Pathology, School of Basic Medicine, Anhui Medical University, Hefei, Anhui, China
| | - Guiyang Huang
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tianyun Wang
- Department of Medical Genetics, Center for Medical Genetics, Peking University Health Science Center, Beijing, China; Neuroscience Research Institute, Peking University, Key Laboratory for Neuroscience, Ministry of Education of China & National Health Commission of China, Beijing, China; Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington
| | - Weicheng Duan
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Hua Li
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yirong Wang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Huiting Jia
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ziqian Yang
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Kang Wang
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Xufeng Chu
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | | | - Kaitlyn Ahlers
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, Washington
| | - Rachel K Earl
- Department of Psychiatry & Behavioral Sciences, University of Washington, Seattle, Washington
| | - Yunyun Han
- Department of Neurobiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | | | - Wendy K Chung
- Simons Foundation, New York; Department of Pediatrics, Columbia University, New York
| | - Evan E Eichler
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington; Howard Hughes Medical Institute, University of Washington, Seattle, Washington
| | - Man Jiang
- Department of Physiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
| | - Bo Xiong
- Department of Forensic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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8
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Construction of a Diagnostic m7G Regulator-Mediated Scoring Model for Identifying the Characteristics and Immune Landscapes of Osteoarthritis. Biomolecules 2023; 13:biom13030539. [PMID: 36979474 PMCID: PMC10046530 DOI: 10.3390/biom13030539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 02/24/2023] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
With the increasingly serious burden of osteoarthritis (OA) on modern society, it is urgent to propose novel diagnostic biomarkers and differentiation models for OA. 7-methylguanosine (m7G), as one of the most common base modification forms in post transcriptional regulation, through which the seventh position N of guanine (G) of messenger RNA is modified by methyl under the action of methyltransferase; it has been found that it plays a crucial role in different diseases. Therefore, we explored the relationship between OA and m7G. Based on the expression level of 18 m7G-related regulators, we identified nine significant regulators. Then, via a series of methods of machine learning, such as support vector machine recursive feature elimination, random forest and lasso-cox regression analysis, a total of four significant regulators were further identified (DCP2, EIF4E2, LARP1 and SNUPN). Additionally, according to the expression level of the above four regulators, two different m7G-related clusters were divided via consensus cluster analysis. Furthermore, via immune infiltration, differential expression analysis and enrichment analysis, we explored the characteristic of the above two different clusters. An m7G-related scoring model was constructed via the PCA algorithm. Meanwhile, there was a different immune status and correlation for immune checkpoint inhibitors between the above two clusters. The expression difference of the above four regulators was verified via real-time quantitative polymerase chain reaction. Overall, a total of four biomarkers were identified and two different m7G-related subsets of OA with different immune microenvironment were obtained. Meanwhile, the construction of m7G-related Scoring model may provide some new strategies and insights for the therapy and diagnosis of OA patients.
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9
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Christie M, Igreja C. eIF4E-homologous protein (4EHP): a multifarious cap-binding protein. FEBS J 2023; 290:266-285. [PMID: 34758096 DOI: 10.1111/febs.16275] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 02/05/2023]
Abstract
The cap-binding protein 4EHP/eIF4E2 has been a recent object of interest in the field of post-transcriptional gene regulation and translational control. From ribosome-associated quality control, to RNA decay and microRNA-mediated gene silencing, this member of the eIF4E protein family regulates gene expression through numerous pathways. Low in abundance but ubiquitously expressed, 4EHP interacts with different binding partners to form multiple protein complexes that regulate translation in a variety of biological contexts. Documented functions of 4EHP primarily relate to its role as a translational repressor, but recent findings indicate that it might also participate in the activation of translation in specific settings. In this review, we discuss the known functions, properties and mechanisms that involve 4EHP in the control of gene expression. We also discuss our current understanding of how 4EHP processes are regulated in eukaryotic cells, and the diseases implicated with dysregulation of 4EHP-mediated translational control.
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Affiliation(s)
- Mary Christie
- School of Life and Environmental Sciences, The University of Sydney, NSW, Australia
| | - Cátia Igreja
- Department for Integrative Evolutionary Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
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10
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DAP5 enables main ORF translation on mRNAs with structured and uORF-containing 5' leaders. Nat Commun 2022; 13:7510. [PMID: 36473845 PMCID: PMC9726905 DOI: 10.1038/s41467-022-35019-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 11/16/2022] [Indexed: 12/12/2022] Open
Abstract
Half of mammalian transcripts contain short upstream open reading frames (uORFs) that potentially regulate translation of the downstream coding sequence (CDS). The molecular mechanisms governing these events remain poorly understood. Here, we find that the non-canonical initiation factor Death-associated protein 5 (DAP5 or eIF4G2) is required for translation initiation on select transcripts. Using ribosome profiling and luciferase-based reporters coupled with mutational analysis we show that DAP5-mediated translation occurs on messenger RNAs (mRNAs) with long, structure-prone 5' leader sequences and persistent uORF translation. These mRNAs preferentially code for signalling factors such as kinases and phosphatases. We also report that cap/eIF4F- and eIF4A-dependent recruitment of DAP5 to the mRNA facilitates main CDS, but not uORF, translation suggesting a role for DAP5 in translation re-initiation. Our study reveals important mechanistic insights into how a non-canonical translation initiation factor involved in stem cell fate shapes the synthesis of specific signalling factors.
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11
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Lehner MH, Walker J, Temcinaite K, Herlihy A, Taschner M, Berger AC, Corbett AH, Dirac Svejstrup AB, Svejstrup JQ. Yeast Smy2 and its human homologs GIGYF1 and -2 regulate Cdc48/VCP function during transcription stress. Cell Rep 2022; 41:111536. [PMID: 36288698 PMCID: PMC9638028 DOI: 10.1016/j.celrep.2022.111536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 06/09/2022] [Accepted: 09/29/2022] [Indexed: 12/02/2022] Open
Abstract
The "last resort" pathway results in ubiquitylation and degradation of RNA polymerase II in response to transcription stress and is governed by factors such as Def1 in yeast. Here, we show that the SMY2 gene acts as a multi-copy suppressor of DEF1 deletion and functions at multiple steps of the last resort pathway. We also provide genetic and biochemical evidence from disparate cellular processes that Smy2 works more broadly as a hitherto overlooked regulator of Cdc48 function. Similarly, the Smy2 homologs GIGYF1 and -2 affect the transcription stress response in human cells and regulate the function of the Cdc48 homolog VCP/p97, presently being explored as a target for cancer therapy. Indeed, we show that the apoptosis-inducing effect of VCP inhibitors NMS-873 and CB-5083 is GIGYF1/2 dependent.
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Affiliation(s)
- Michelle Harreman Lehner
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Jane Walker
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Kotryna Temcinaite
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Anna Herlihy
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Michael Taschner
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Adam C Berger
- Department of Biology, RRC 1021, Emory University, 1510 Clifton Road, NE, Atlanta 30322, GA, USA
| | - Anita H Corbett
- Department of Biology, RRC 1021, Emory University, 1510 Clifton Road, NE, Atlanta 30322, GA, USA
| | - A Barbara Dirac Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK; Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
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12
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Maciej VD, Mateva N, Schwarz J, Dittmers T, Mallick M, Urlaub H, Chakrabarti S. Intrinsically disordered regions of tristetraprolin and DCP2 directly interact to mediate decay of ARE-mRNA. Nucleic Acids Res 2022; 50:10665-10679. [PMID: 36130271 PMCID: PMC9561381 DOI: 10.1093/nar/gkac797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 08/30/2022] [Accepted: 09/06/2022] [Indexed: 11/25/2022] Open
Abstract
The RNA-binding protein tristetraprolin (TTP) is a potent activator of mRNA decay, specifically for transcripts bearing AU-rich elements (AREs) in their 3′-untranslated regions. TTP functions as a mediator for mRNA decay by interacting with the decay machinery and recruiting it to the target ARE-mRNA. In this study, we report a weak, but direct interaction between TTP and the human decapping enzyme DCP2, which impacts the stability of ARE transcripts. The TTP–DCP2 interaction is unusual as it involves intrinsically disordered regions (IDRs) of both binding partners. We show that the IDR of DCP2 has a propensity for oligomerization and liquid–liquid phase separation in vitro. Binding of TTP to DCP2 leads to its partitioning into phase-separated droplets formed by DCP2, suggesting that molecular crowding might facilitate the weak interaction between the two proteins and enable assembly of a decapping-competent mRNA–protein complex on TTP-bound transcripts in cells. Our studies underline the role of weak interactions in the cellular interaction network and their contribution towards cellular functionality.
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Affiliation(s)
- Vincent D Maciej
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
| | - Nevena Mateva
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
| | - Juliane Schwarz
- Max Planck Institute for Multidisciplinary Sciences, Bioanalytical Mass Spectrometry Group, Am Fassberg 11, D-37077 Goettingen, Germany.,University Medical Center Goettingen, Bioanalytics, Institute for Clinical Chemistry, Robert Koch Strasse 40, D-37075 Goettingen, Germany
| | - Theresa Dittmers
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
| | - Megha Mallick
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
| | - Henning Urlaub
- Max Planck Institute for Multidisciplinary Sciences, Bioanalytical Mass Spectrometry Group, Am Fassberg 11, D-37077 Goettingen, Germany.,University Medical Center Goettingen, Bioanalytics, Institute for Clinical Chemistry, Robert Koch Strasse 40, D-37075 Goettingen, Germany
| | - Sutapa Chakrabarti
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany
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13
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Reiter KH, Zelter A, Janowska MK, Riffle M, Shulman N, MacLean BX, Tamura K, Chambers MC, MacCoss MJ, Davis TN, Guttman M, Brzovic PS, Klevit RE. Cullin-independent recognition of HHARI substrates by a dynamic RBR catalytic domain. Structure 2022; 30:1269-1284.e6. [PMID: 35716664 PMCID: PMC9444911 DOI: 10.1016/j.str.2022.05.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/15/2022] [Accepted: 05/24/2022] [Indexed: 11/27/2022]
Abstract
RING-between-RING (RBR) E3 ligases mediate ubiquitin transfer through an obligate E3-ubiquitin thioester intermediate prior to substrate ubiquitination. Although RBRs share a conserved catalytic module, substrate recruitment mechanisms remain enigmatic, and the relevant domains have yet to be identified for any member of the class. Here we characterize the interaction between the auto-inhibited RBR, HHARI (AriH1), and its target protein, 4EHP, using a combination of XL-MS, HDX-MS, NMR, and biochemical studies. The results show that (1) a di-aromatic surface on the catalytic HHARI Rcat domain forms a binding platform for substrates and (2) a phosphomimetic mutation on the auto-inhibitory Ariadne domain of HHARI promotes release and reorientation of Rcat for transthiolation and substrate modification. The findings identify a direct binding interaction between a RING-between-RING ligase and its substrate and suggest a general model for RBR substrate recognition.
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Affiliation(s)
- Katherine H Reiter
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Alex Zelter
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Maria K Janowska
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Michael Riffle
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Nicholas Shulman
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Brendan X MacLean
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Kaipo Tamura
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Matthew C Chambers
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Michael J MacCoss
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Peter S Brzovic
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA
| | - Rachel E Klevit
- Department of Biochemistry, University of Washington, Seattle, WA 98195, USA.
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14
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SARS-CoV-2 impairs interferon production via NSP2-induced repression of mRNA translation. Proc Natl Acad Sci U S A 2022; 119:e2204539119. [PMID: 35878012 PMCID: PMC9371684 DOI: 10.1073/pnas.2204539119] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
A robust antiviral innate immune response is indispensable for combating infections. However, an exacerbated response can result in pathological inflammation and tissue damage. mRNA translational control mechanisms play a crucial role in maintaining the appropriate magnitude and duration of the immune response. We show that the GIGYF2/4EHP translational repressor complex represses translation of Ifnb1 mRNA, which encodes type I interferon β (IFN-β). We also demonstrate that the NSP2 protein encoded by SARS-CoV-2 virus further impedes translation of Ifnb1 mRNA through coopting the GIGYF2/4EHP complex, leading to evasion of a cellular innate immune response. The knowledge of the mechanism of action of NSP2-mediated IFN-β suppression provides valuable information for development of treatments for infections of SARS-CoV-2 and other coronaviruses. Viruses evade the innate immune response by suppressing the production or activity of cytokines such as type I interferons (IFNs). Here we report the discovery of a mechanism by which the SARS-CoV-2 virus coopts an intrinsic cellular machinery to suppress the production of the key immunostimulatory cytokine IFN-β. We reveal that the SARS-CoV-2 encoded nonstructural protein 2 (NSP2) directly interacts with the cellular GIGYF2 protein. This interaction enhances the binding of GIGYF2 to the mRNA cap-binding protein 4EHP, thereby repressing the translation of the Ifnb1 mRNA. Depletion of GIGYF2 or 4EHP significantly enhances IFN-β production, which inhibits SARS-CoV-2 replication. Our findings reveal a target for rescuing the antiviral innate immune response to SARS-CoV-2 and other RNA viruses.
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15
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Zou L, Moch C, Graille M, Chapat C. The SARS-CoV-2 protein NSP2 impairs the silencing capacity of the human 4EHP-GIGYF2 complex. iScience 2022; 25:104646. [PMID: 35756894 PMCID: PMC9213009 DOI: 10.1016/j.isci.2022.104646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 05/12/2022] [Accepted: 06/15/2022] [Indexed: 01/20/2023] Open
Abstract
There is an urgent need for a molecular understanding of how SARS-CoV-2 influences the machineries of the host cell. Herein, we focused our attention on the capacity of the SARS-CoV-2 protein NSP2 to bind the human 4EHP-GIGYF2 complex, a key factor involved in microRNA-mediated silencing of gene expression. Using in vitro interaction assays, our data demonstrate that NSP2 physically associates with both 4EHP and a central segment in GIGYF2 in the cytoplasm. We also provide functional evidence showing that NSP2 impairs the function of GIGYF2 in mediating translation repression using reporter-based assays. Collectively, these data reveal the potential impact of NSP2 on the post-transcriptional silencing of gene expression in human cells, pointing out 4EHP-GIGYF2 targeting as a possible strategy of SARS-CoV-2 to take over the silencing machinery and to suppress host defenses.
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Affiliation(s)
- Limei Zou
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Clara Moch
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
| | - Clément Chapat
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, IP Paris. F-91128 Palaiseau, France
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16
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Chen R, Tu Z, He C, Nie X, Li K, Fei S, Song B, Nie B, Xie C. Susceptibility factor StEXA1 interacts with StnCBP to facilitate potato virus Y accumulation through the stress granule-dependent RNA regulatory pathway in potato. HORTICULTURE RESEARCH 2022; 9:uhac159. [PMID: 36204208 PMCID: PMC9531334 DOI: 10.1093/hr/uhac159] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/22/2022] [Accepted: 07/06/2022] [Indexed: 06/16/2023]
Abstract
Plant viruses recruit multiple host factors for translation, replication, and movement in the infection process. The loss-of-function mutation of the susceptibility genes will lead to the loss of susceptibility to viruses, which is referred to as 'recessive resistance'. Essential for potexvirus Accumulation 1 (EXA1) has been identified as a susceptibility gene required for potexvirus, lolavirus, and bacterial and oomycete pathogens. In this study, EXA1 knockdown in potato (StEXA1) was found to confer novel resistance to potato virus Y (PVY, potyvirus) in a strain-specific manner. It significantly compromised PVYO accumulation but not PVYN:O and PVYNTN. Further analysis revealed that StEXA1 is associated with the HC-Pro of PVY through a member of eIF4Es (StnCBP). HC-ProO and HC-ProN, two HC-Pro proteins from PVYO and PVYN, exhibited strong and weak interactions with StnCBP, respectively, due to their different spatial conformation. Moreover, the accumulation of PVYO was mainly dependent on the stress granules (SGs) induced by StEXA1 and StnCBP, whereas PVYN:O and PVYNTN could induce SGs by HC-ProN independently through an unknown mechanism. These results could explain why StEXA1 or StnCBP knockdown conferred resistance to PVYO but not to PVYN:O and PVYNTN. In summary, our results for the first time demonstrate that EXA1 can act as a susceptibility gene for PVY infection. Finally, a hypothetical model was proposed for understanding the mechanism by which StEXA1 interacts with StnCBP to facilitate PVY accumulation in potato through the SG-dependent RNA regulatory pathway.
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Affiliation(s)
- Ruhao Chen
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
- ERC for Germplasm Innovation and New Variety Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, Hunan Agricultural University, Changsha, 410128, China
| | - Zhen Tu
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Changzheng He
- ERC for Germplasm Innovation and New Variety Breeding of Horticultural Crops, Key Laboratory for Vegetable Biology of Hunan Province, Hunan Agricultural University, Changsha, 410128, China
| | - Xianzhou Nie
- Fredericton Research and Development Centre, Agriculture and Agri-Food Canada, Fredericton, New Brunswick, E3B 4Z7,
Canada
| | - Kun Li
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Sitian Fei
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | - Botao Song
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
| | | | - Conghua Xie
- Key Laboratory of Potato Biology and Biotechnology (HZAU), Ministry of Agriculture and Rural Affairs, Key Laboratory of Horticultural Plant Biology (HZAU), Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China
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17
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Epstein-Barr Virus BGLF2 commandeers RISC to interfere with cellular miRNA function. PLoS Pathog 2022; 18:e1010235. [PMID: 35007297 PMCID: PMC8782528 DOI: 10.1371/journal.ppat.1010235] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 01/21/2022] [Accepted: 12/27/2021] [Indexed: 01/27/2023] Open
Abstract
The Epstein-Barr virus (EBV) BGLF2 protein is a tegument protein with multiple effects on the cellular environment, including induction of SUMOylation of cellular proteins. Using affinity-purification coupled to mass-spectrometry, we identified the miRNA-Induced Silencing Complex (RISC), essential for miRNA function, as a top interactor of BGLF2. We confirmed BGLF2 interaction with the Ago2 and TNRC6 components of RISC in multiple cell lines and their co-localization in cytoplasmic bodies that also contain the stress granule marker G3BP1. In addition, BGLF2 expression led to the loss of processing bodies in multiple cell types, suggesting disruption of RISC function in mRNA regulation. Consistent with this observation, BGLF2 disrupted Ago2 association with multiple miRNAs. Using let-7 miRNAs as a model, we tested the hypothesis that BGLF2 interfered with the function of RISC in miRNA-mediated mRNA silencing. Using multiple reporter constructs with 3’UTRs containing let-7a regulated sites, we showed that BGLF2 inhibited let-7a miRNA activity dependent on these 3’UTRs, including those from SUMO transcripts which are known to be regulated by let-7 miRNAs. In keeping with these results, we showed that BGLF2 increased the cellular level of unconjugated SUMO proteins without affecting the level of SUMO transcripts. Such an increase in free SUMO is known to drive SUMOylation and would account for the effect of BGLF2 in inducing SUMOylation. We further showed that BGLF2 expression inhibited the loading of let-7 miRNAs into Ago2 proteins, and conversely, that lytic infection with EBV lacking BGLF2 resulted in increased interaction of let-7a and SUMO transcripts with Ago2, relative to WT EBV infection. Therefore, we have identified a novel role for BGLF2 as a miRNA regulator and shown that one outcome of this activity is the dysregulation of SUMO transcripts that leads to increased levels of free SUMO proteins and SUMOylation. Epstein-Barr virus (EBV) infects most people worldwide, persists for life and is associated with several kinds of cancer. In order to undergo efficient lytic infection, EBV must manipulate multiple cellular pathways. BGLF2 is an EBV lytic protein known to modulate several cellular processes including increasing the modification of cellular proteins with the Small Ubiquitin-Like Modifier (SUMO), a process referred to as SUMOylation. Here we show for the first time that BGLF2 interacts with a cellular complex (RISC) required for miRNA function and interferes with the function of some cellular miRNAs by sequestering this complex. One of the consequences of this effect is the increased expression of SUMO proteins, due to inhibition of the miRNAs that normally downregulate their expression. The resulting increase in SUMO proteins drives SUMOylation, providing a mechanism for the previously reported BGLF2-induced SUMOylation of cellular proteins. In addition, the discovery of BGLF2 as a miRNA regulator suggests that this EBV protein can control many cellular pathways by interfering with cellular miRNAs that normally regulate them.
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18
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Falk F, Kamanyi Marucha K, Clayton C. The EIF4E1-4EIP cap-binding complex of Trypanosoma brucei interacts with the terminal uridylyl transferase TUT3. PLoS One 2021; 16:e0258903. [PMID: 34807934 PMCID: PMC8608314 DOI: 10.1371/journal.pone.0258903] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/16/2021] [Indexed: 11/25/2022] Open
Abstract
Most transcription in Trypanosoma brucei is constitutive and polycistronic. Consequently, the parasite relies on post-transcriptional mechanisms, especially affecting translation initiation and mRNA decay, to control gene expression both at steady-state and for adaptation to different environments. The parasite has six isoforms of the cap-binding protein EIF4E as well as five EIF4Gs. EIF4E1 does not bind to any EIF4G, instead being associated with a 4E-binding protein, 4EIP. 4EIP represses translation and reduces the stability of a reporter mRNA when artificially tethered to the 3’-UTR, whether or not EIF4E1 is present. 4EIP is essential during the transition from the mammalian bloodstream form to the procyclic form that lives in the Tsetse vector. In contrast, EIF4E1 is dispensable during differentiation, but is required for establishment of growing procyclic forms. In Leishmania, there is some evidence that EIF4E1 might be active in translation initiation, via direct recruitment of EIF3. However in T. brucei, EIF4E1 showed no detectable association with other translation initiation factors, even in the complete absence of 4EIP. There was some evidence for interactions with NOT complex components, but if these occur they must be weak and transient. We found that EIF4E1is less abundant in the absence of 4EIP, and RNA pull-down results suggested this might occur through co-translational complex assembly. We also report that 4EIP directly recruits the cytosolic terminal uridylyl transferase TUT3 to EIF4E1/4EIP complexes. There was, however, no evidence that TUT3 is essential for 4EIP function.
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Affiliation(s)
- Franziska Falk
- DKFZ-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Kevin Kamanyi Marucha
- DKFZ-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
| | - Christine Clayton
- DKFZ-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), Heidelberg, Germany
- * E-mail:
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19
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Deaton AM, Parker MM, Ward LD, Flynn-Carroll AO, BonDurant L, Hinkle G, Akbari P, Lotta LA, Baras A, Nioi P. Gene-level analysis of rare variants in 379,066 whole exome sequences identifies an association of GIGYF1 loss of function with type 2 diabetes. Sci Rep 2021; 11:21565. [PMID: 34732801 PMCID: PMC8566487 DOI: 10.1038/s41598-021-99091-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 09/15/2021] [Indexed: 11/15/2022] Open
Abstract
Sequencing of large cohorts offers an unprecedented opportunity to identify rare genetic variants and to find novel contributors to human disease. We used gene-based collapsing tests to identify genes associated with glucose, HbA1c and type 2 diabetes (T2D) diagnosis in 379,066 exome-sequenced participants in the UK Biobank. We identified associations for variants in GCK, HNF1A and PDX1, which are known to be involved in Mendelian forms of diabetes. Notably, we uncovered novel associations for GIGYF1, a gene not previously implicated by human genetics in diabetes. GIGYF1 predicted loss of function (pLOF) variants associated with increased levels of glucose (0.77 mmol/L increase, p = 4.42 × 10–12) and HbA1c (4.33 mmol/mol, p = 1.28 × 10–14) as well as T2D diagnosis (OR = 4.15, p = 6.14 × 10–11). Multiple rare variants contributed to these associations, including singleton variants. GIGYF1 pLOF also associated with decreased cholesterol levels as well as an increased risk of hypothyroidism. The association of GIGYF1 pLOF with T2D diagnosis replicated in an independent cohort from the Geisinger Health System. In addition, a common variant association for glucose and T2D was identified at the GIGYF1 locus. Our results highlight the role of GIGYF1 in regulating insulin signaling and protecting from diabetes.
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Affiliation(s)
| | | | | | | | | | | | - Parsa Akbari
- Regeneron Genetics Center, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Luca A Lotta
- Regeneron Genetics Center, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | | | | | - Aris Baras
- Regeneron Genetics Center, Regeneron Pharmaceuticals, Tarrytown, NY, USA
| | - Paul Nioi
- Alnylam Pharmaceuticals, Cambridge, MA, USA
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20
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Weber R, Chung MY, Keskeny C, Zinnall U, Landthaler M, Valkov E, Izaurralde E, Igreja C. 4EHP and GIGYF1/2 Mediate Translation-Coupled Messenger RNA Decay. Cell Rep 2021; 33:108262. [PMID: 33053355 DOI: 10.1016/j.celrep.2020.108262] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 08/26/2020] [Accepted: 09/22/2020] [Indexed: 12/13/2022] Open
Abstract
Current models of mRNA turnover indicate that cytoplasmic degradation is coupled with translation. However, our understanding of the molecular events that coordinate ribosome transit with the mRNA decay machinery is still limited. Here, we show that 4EHP-GIGYF1/2 complexes trigger co-translational mRNA decay. Human cells lacking these proteins accumulate mRNAs with prominent ribosome pausing. They include, among others, transcripts encoding secretory and membrane-bound proteins or tubulin subunits. In addition, 4EHP-GIGYF1/2 complexes fail to reduce mRNA levels in the absence of ribosome stalling or upon disruption of their interaction with the cap structure, DDX6, and ZNF598. We further find that co-translational binding of GIGYF1/2 to the mRNA marks transcripts with perturbed elongation to decay. Our studies reveal how a repressor complex linked to neurological disorders minimizes the protein output of a subset of mRNAs.
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Affiliation(s)
- Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Min-Yi Chung
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Csilla Keskeny
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Ulrike Zinnall
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Markus Landthaler
- Berlin Institute for Medical Systems Biology (BIMSB), Max Delbrück Center for Molecular Medicine in the Helmholtz Association (MDC), 10115 Berlin, Germany; IRI Life Sciences, Institute für Biologie, Humboldt Universität zu Berlin, 10115 Berlin, Germany
| | - Eugene Valkov
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.
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21
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Nordgaard C, Tollenaere MAX, Val AMD, Bekker-Jensen DB, Blasius M, Olsen JV, Bekker-Jensen S. Regulation of the Golgi Apparatus by p38 and JNK Kinases during Cellular Stress Responses. Int J Mol Sci 2021; 22:ijms22179595. [PMID: 34502507 PMCID: PMC8431686 DOI: 10.3390/ijms22179595] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/20/2021] [Accepted: 08/31/2021] [Indexed: 12/15/2022] Open
Abstract
p38 and c-Jun N-terninal kinase (JNK) are activated in response to acute stress and inflammatory signals. Through modification of a plethora of substrates, these kinases profoundly re-shape cellular physiology for the optimal response to a harmful environment and/or an inflammatory state. Here, we utilized phospho-proteomics to identify several hundred substrates for both kinases. Our results indicate that the scale of signaling from p38 and JNK are of a similar magnitude. Among the many new targets, we highlight the regulation of the transcriptional regulators grb10-interacting GYF protein 1 and 2 (GIGYF1/2) by p38-dependent MAP kinase-activated protein kinase 2 (MK2) phosphorylation and 14–3–3 binding. We also show that the Golgi apparatus contains numerous substrates, and is a major target for regulation by p38 and JNK. When activated, these kinases mediate structural rearrangement of the Golgi apparatus, which positively affects protein flux through the secretory system. Our work expands on our knowledge about p38 and JNK signaling with important biological ramifications.
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Affiliation(s)
- Cathrine Nordgaard
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (C.N.); (M.A.X.T.); (M.B.)
| | - Maxim A. X. Tollenaere
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (C.N.); (M.A.X.T.); (M.B.)
- LEO Pharma A/S, Industriparken 55, 2750 Ballerup, Denmark
| | - Ana Martinez Del Val
- Mass Spectrometry for Quantitative Proteomics, Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.M.D.V.); (D.B.B.-J.); (J.V.O.)
| | - Dorte B. Bekker-Jensen
- Mass Spectrometry for Quantitative Proteomics, Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.M.D.V.); (D.B.B.-J.); (J.V.O.)
| | - Melanie Blasius
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (C.N.); (M.A.X.T.); (M.B.)
| | - Jesper V. Olsen
- Mass Spectrometry for Quantitative Proteomics, Proteomics Program, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.M.D.V.); (D.B.B.-J.); (J.V.O.)
| | - Simon Bekker-Jensen
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (C.N.); (M.A.X.T.); (M.B.)
- Correspondence: ; Tel.: +45-20-20-49-93
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22
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Jensen KB, Dredge BK, Toubia J, Jin X, Iadevaia V, Goodall GJ, Proud CG. capCLIP: a new tool to probe translational control in human cells through capture and identification of the eIF4E-mRNA interactome. Nucleic Acids Res 2021; 49:e105. [PMID: 34255842 PMCID: PMC8501963 DOI: 10.1093/nar/gkab604] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 06/16/2021] [Accepted: 07/06/2021] [Indexed: 12/21/2022] Open
Abstract
Translation of eukaryotic mRNAs begins with binding of their m7G cap to eIF4E, followed by recruitment of other translation initiation factor proteins. We describe capCLIP, a novel method to comprehensively capture and quantify the eIF4E (eukaryotic initiation factor 4E) 'cap-ome' and apply it to examine the biological consequences of eIF4E-cap binding in distinct cellular contexts. First, we use capCLIP to identify the eIF4E cap-omes in human cells with/without the mTORC1 (mechanistic target of rapamycin, complex 1) inhibitor rapamycin, there being an emerging consensus that rapamycin inhibits translation of TOP (terminal oligopyrimidine) mRNAs by displacing eIF4E from their caps. capCLIP reveals that the representation of TOP mRNAs in the cap-ome is indeed systematically reduced by rapamycin, thus validating our new methodology. capCLIP also refines the requirements for a functional TOP sequence. Second, we apply capCLIP to probe the consequences of phosphorylation of eIF4E. We show eIF4E phosphorylation reduces overall eIF4E-mRNA association and, strikingly, causes preferential dissociation of mRNAs with short 5'-UTRs. capCLIP is a valuable new tool to probe the function of eIF4E and of other cap-binding proteins such as eIF4E2/eIF4E3.
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Affiliation(s)
- Kirk B Jensen
- Lifelong Health, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia.,School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - B Kate Dredge
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia
| | - John Toubia
- Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia.,ACRF Cancer Genomics Facility, Centre for Cancer Biology, SA Pathology and University of South Australia, Frome Road, Adelaide, SA 5000, Australia
| | - Xin Jin
- Lifelong Health, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia.,School of Medicine and Pharmacy, Ocean University of China, 5 Yushan Road, Qingdao 266003, China
| | - Valentina Iadevaia
- School of Biosciences and Medicine, University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Gregory J Goodall
- School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA 5005, Australia.,Centre for Cancer Biology, SA Pathology and University of South Australia, Adelaide, SA 5000, Australia.,Adelaide Medical School, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, SA 5005, Australia
| | - Christopher G Proud
- Lifelong Health, South Australian Health and Medical Research Institute, North Terrace, Adelaide, SA 5000, Australia.,School of Biological Sciences, Faculty of Sciences, University of Adelaide, Adelaide, SA 5005, Australia
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23
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GIGYF1 loss of function is associated with clonal mosaicism and adverse metabolic health. Nat Commun 2021; 12:4178. [PMID: 34234147 PMCID: PMC8263756 DOI: 10.1038/s41467-021-24504-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 06/21/2021] [Indexed: 12/01/2022] Open
Abstract
Mosaic loss of chromosome Y (LOY) in leukocytes is the most common form of clonal mosaicism, caused by dysregulation in cell-cycle and DNA damage response pathways. Previous genetic studies have focussed on identifying common variants associated with LOY, which we now extend to rarer, protein-coding variation using exome sequences from 82,277 male UK Biobank participants. We find that loss of function of two genes—CHEK2 and GIGYF1—reach exome-wide significance. Rare alleles in GIGYF1 have not previously been implicated in any complex trait, but here loss-of-function carriers exhibit six-fold higher susceptibility to LOY (OR = 5.99 [3.04–11.81], p = 1.3 × 10−10). These same alleles are also associated with adverse metabolic health, including higher susceptibility to Type 2 Diabetes (OR = 6.10 [3.51–10.61], p = 1.8 × 10−12), 4 kg higher fat mass (p = 1.3 × 10−4), 2.32 nmol/L lower serum IGF1 levels (p = 1.5 × 10−4) and 4.5 kg lower handgrip strength (p = 4.7 × 10−7) consistent with proposed GIGYF1 enhancement of insulin and IGF-1 receptor signalling. These associations are mirrored by a common variant nearby associated with the expression of GIGYF1. Our observations highlight a potential direct connection between clonal mosaicism and metabolic health. Mosaic loss of chromosome Y (LOY) is a common form of clonal mosaicism in leukocytes. Here, the authors extend genetic association analyses to rare variation using exome-sequence data from 82,277 males, finding that loss-of-function alleles in GIGYF1 are associated with six-fold higher susceptibility to both LOY and Type 2 Diabetes.
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24
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Mayya VK, Flamand MN, Lambert AM, Jafarnejad SM, Wohlschlegel JA, Sonenberg N, Duchaine TF. microRNA-mediated translation repression through GYF-1 and IFE-4 in C. elegans development. Nucleic Acids Res 2021; 49:4803-4815. [PMID: 33758928 PMCID: PMC8136787 DOI: 10.1093/nar/gkab162] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 02/24/2021] [Accepted: 03/17/2021] [Indexed: 12/11/2022] Open
Abstract
microRNA (miRNA)-mediated gene silencing is enacted through the recruitment of effector proteins that direct translational repression or degradation of mRNA targets, but the relative importance of their activities for animal development remains unknown. Our concerted proteomic surveys identified the uncharacterized GYF-domain encoding protein GYF-1 and its direct interaction with IFE-4, the ortholog of the mammalian translation repressor 4EHP, as key miRNA effector proteins in Caenorhabditis elegans. Recruitment of GYF-1 protein to mRNA reporters in vitro or in vivo leads to potent translation repression without affecting the poly(A) tail or impinging on mRNA stability. Loss of gyf-1 is synthetic lethal with hypomorphic alleles of embryonic miR-35-42 and larval (L4) let-7 miRNAs, which is phenocopied through engineered mutations in gyf-1 that abolish interaction with IFE-4. GYF-1/4EHP function is cascade-specific, as loss of gyf-1 had no noticeable impact on the functions of other miRNAs, including lin-4 and lsy-6. Overall, our findings reveal the first direct effector of miRNA-mediated translational repression in C. elegans and its physiological importance for the function of several, but likely not all miRNAs.
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Affiliation(s)
- Vinay K Mayya
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Mathieu N Flamand
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Alice M Lambert
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Seyed Mehdi Jafarnejad
- Patrick G. Johnston Centre for Cancer Research, Queen's University of Belfast, Belfast BT9 7AE UK
| | - James A Wohlschlegel
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Nahum Sonenberg
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
| | - Thomas F Duchaine
- Goodman Cancer Research Center, McGill University, Montréal H3G 1Y6, Canada.,Department of Biochemistry, McGill University, Montréal H3G 1Y6, Canada
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25
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Scheer H, de Almeida C, Ferrier E, Simonnot Q, Poirier L, Pflieger D, Sement FM, Koechler S, Piermaria C, Krawczyk P, Mroczek S, Chicher J, Kuhn L, Dziembowski A, Hammann P, Zuber H, Gagliardi D. The TUTase URT1 connects decapping activators and prevents the accumulation of excessively deadenylated mRNAs to avoid siRNA biogenesis. Nat Commun 2021; 12:1298. [PMID: 33637717 PMCID: PMC7910438 DOI: 10.1038/s41467-021-21382-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 01/19/2021] [Indexed: 12/15/2022] Open
Abstract
Uridylation is a widespread modification destabilizing eukaryotic mRNAs. Yet, molecular mechanisms underlying TUTase-mediated mRNA degradation remain mostly unresolved. Here, we report that the Arabidopsis TUTase URT1 participates in a molecular network connecting several translational repressors/decapping activators. URT1 directly interacts with DECAPPING 5 (DCP5), the Arabidopsis ortholog of human LSM14 and yeast Scd6, and this interaction connects URT1 to additional decay factors like DDX6/Dhh1-like RNA helicases. Nanopore direct RNA sequencing reveals a global role of URT1 in shaping poly(A) tail length, notably by preventing the accumulation of excessively deadenylated mRNAs. Based on in vitro and in planta data, we propose a model that explains how URT1 could reduce the accumulation of oligo(A)-tailed mRNAs both by favoring their degradation and because 3' terminal uridines intrinsically hinder deadenylation. Importantly, preventing the accumulation of excessively deadenylated mRNAs avoids the biogenesis of illegitimate siRNAs that silence endogenous mRNAs and perturb Arabidopsis growth and development.
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Affiliation(s)
- Hélène Scheer
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Caroline de Almeida
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Emilie Ferrier
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Quentin Simonnot
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Laure Poirier
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - David Pflieger
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - François M Sement
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Sandrine Koechler
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France
| | - Christina Piermaria
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Paweł Krawczyk
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Seweryn Mroczek
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Johana Chicher
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Lauriane Kuhn
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Andrzej Dziembowski
- Laboratory of RNA Biology, International Institute of Molecular and Cell Biology, Warsaw, Poland
- Faculty of Biology, Institute of Genetics and Biotechnology, University of Warsaw, Warsaw, Poland
| | - Philippe Hammann
- Plateforme Protéomique Strasbourg Esplanade du CNRS, Université de Strasbourg, Strasbourg, France
| | - Hélène Zuber
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
| | - Dominique Gagliardi
- Institut de biologie moléculaire des plantes, CNRS, Université de Strasbourg, Strasbourg, France.
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26
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microRNA-induced translational control of antiviral immunity by the cap-binding protein 4EHP. Mol Cell 2021; 81:1187-1199.e5. [PMID: 33581076 DOI: 10.1016/j.molcel.2021.01.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 01/19/2021] [Accepted: 01/21/2021] [Indexed: 12/14/2022]
Abstract
Type I interferons (IFNs) are critical cytokines in the host defense against invading pathogens. Sustained production of IFNs, however, is detrimental to the host, as it provokes autoimmune diseases. Thus, the expression of IFNs is tightly controlled. We report that the mRNA 5' cap-binding protein 4EHP plays a key role in regulating type I IFN concomitant with controlling virus replication, both in vitro and in vivo. Mechanistically, 4EHP suppresses IFN-β production by effecting the miR-34a-induced translational silencing of Ifnb1 mRNA. miR-34a is upregulated by both RNA virus infection and IFN-β induction, prompting a negative feedback regulatory mechanism that represses IFN-β expression via 4EHP. These findings demonstrate the direct involvement of 4EHP in virus-induced host response, underscoring a critical translational silencing mechanism mediated by 4EHP and miR-34a to impede sustained IFN production. This study highlights an intrinsic regulatory function for miRNA and the translation machinery in maintaining host homeostasis.
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27
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The eIF4E homolog 4EHP (eIF4E2) regulates hippocampal long-term depression and impacts social behavior. Mol Autism 2020; 11:92. [PMID: 33225984 PMCID: PMC7682028 DOI: 10.1186/s13229-020-00394-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 10/23/2020] [Indexed: 12/27/2022] Open
Abstract
Background The regulation of protein synthesis is a critical step in gene expression, and its dysfunction is implicated in autism spectrum disorder (ASD). The eIF4E homologous protein (4EHP, also termed eIF4E2) binds to the mRNA 5′ cap to repress translation. The stability of 4EHP is maintained through physical interaction with GRB10 interacting GYF protein 2 (GIGYF2). Gene-disruptive mutations in GIGYF2 are linked to ASD, but causality is lacking. We hypothesized that GIGYF2 mutations cause ASD by disrupting 4EHP function. Methods Since homozygous deletion of either gene is lethal, we generated a cell-type-specific knockout model where Eif4e2 (the gene encoding 4EHP) is deleted in excitatory neurons of the forebrain (4EHP-eKO). In this model, we investigated ASD-associated synaptic plasticity dysfunction, ASD-like behaviors, and global translational control. We also utilized mice lacking one copy of Gigyf2, Eif4e2 or co-deletion of one copy of each gene to further investigate ASD-like behaviors. Results 4EHP is expressed in excitatory neurons and synaptosomes, and its amount increases during development. 4EHP-eKO mice display exaggerated mGluR-LTD, a phenotype frequently observed in mouse models of ASD. Consistent with synaptic plasticity dysfunction, the mice displayed social behavior impairments without being confounded by deficits in olfaction, anxiety, locomotion, or motor ability. Repetitive behaviors and vocal communication were not affected by loss of 4EHP in excitatory neurons. Heterozygous deletion of either Gigyf2, Eif4e2, or both genes in mice did not result in ASD-like behaviors (i.e. decreases in social behavior or increases in marble burying). Interestingly, exaggerated mGluR-LTD and impaired social behaviors were not attributed to changes in hippocampal global protein synthesis, which suggests that 4EHP and GIGYF2 regulate the translation of specific mRNAs to mediate these effects. Limitations This study did not identify which genes are translationally regulated by 4EHP and GIGYF2. Identification of mistranslated genes in 4EHP-eKO mice might provide a mechanistic explanation for the observed impairment in social behavior and exaggerated LTD. Future experiments employing affinity purification of translating ribosomes and mRNA sequencing in 4EHP-eKO mice will address this relevant issue. Conclusions Together these results demonstrate an important role of 4EHP in regulating hippocampal plasticity and ASD-associated social behaviors, consistent with the link between mutations in GIGYF2 and ASD.
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28
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Hickey KL, Dickson K, Cogan JZ, Replogle JM, Schoof M, D'Orazio KN, Sinha NK, Hussmann JA, Jost M, Frost A, Green R, Weissman JS, Kostova KK. GIGYF2 and 4EHP Inhibit Translation Initiation of Defective Messenger RNAs to Assist Ribosome-Associated Quality Control. Mol Cell 2020; 79:950-962.e6. [PMID: 32726578 PMCID: PMC7891188 DOI: 10.1016/j.molcel.2020.07.007] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 07/07/2020] [Accepted: 07/07/2020] [Indexed: 12/31/2022]
Abstract
Ribosome-associated quality control (RQC) pathways protect cells from toxicity caused by incomplete protein products resulting from translation of damaged or problematic mRNAs. Extensive work in yeast has identified highly conserved mechanisms that lead to degradation of faulty mRNA and partially synthesized polypeptides. Here we used CRISPR-Cas9-based screening to search for additional RQC strategies in mammals. We found that failed translation leads to specific inhibition of translation initiation on that message. This negative feedback loop is mediated by two translation inhibitors, GIGYF2 and 4EHP. Model substrates and growth-based assays established that inhibition of additional rounds of translation acts in concert with known RQC pathways to prevent buildup of toxic proteins. Inability to block translation of faulty mRNAs and subsequent accumulation of partially synthesized polypeptides could explain the neurodevelopmental and neuropsychiatric disorders observed in mice and humans with compromised GIGYF2 function.
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Affiliation(s)
- Kelsey L Hickey
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Kimberley Dickson
- Department of Biology, Lawerence University, Appleton, WI 54911, USA
| | - J Zachery Cogan
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Joseph M Replogle
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Michael Schoof
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Karole N D'Orazio
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Niladri K Sinha
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jeffrey A Hussmann
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Marco Jost
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Adam Frost
- California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Rachel Green
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA; Howard Hughes Medical Institute, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Jonathan S Weissman
- Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA; California Institute for Quantitative Biomedical Research, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, Carnegie Institution for Science, Baltimore, MD 21218, USA.
| | - Kamena K Kostova
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA.
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29
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Tupperwar N, Meleppattu S, Shrivastava R, Baron N, Gilad A, Wagner G, Léger-Abraham M, Shapira M. A newly identified Leishmania IF4E-interacting protein, Leish4E-IP2, modulates the activity of cap-binding protein paralogs. Nucleic Acids Res 2020; 48:4405-4417. [PMID: 32232353 PMCID: PMC7192595 DOI: 10.1093/nar/gkaa173] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 03/04/2020] [Accepted: 03/16/2020] [Indexed: 01/06/2023] Open
Abstract
Translation of most cellular mRNAs in eukaryotes proceeds through a cap-dependent pathway, whereby the cap-binding complex, eIF4F, anchors the preinitiation complex at the 5′ end of mRNAs and regulates translation initiation. The requirement of Leishmania to survive in changing environments can explain why they encode multiple eIF4E (LeishIF4Es) and eIF4G (LeishIF4Gs) paralogs, as each could be assigned a discrete role during their life cycle. Here we show that the expression and activity of different LeishIF4Es change during the growth of cultured promastigotes, urging a search for regulatory proteins. We describe a novel LeishIF4E-interacting protein, Leish4E-IP2, which contains a conserved Y(X)4LΦ IF4E-binding-motif. Despite its capacity to bind several LeishIF4Es, Leish4E-IP2 was not detected in m7GTP-eluted cap-binding complexes, suggesting that it could inhibit the cap-binding activity of LeishIF4Es. Using a functional assay, we show that a recombinant form of Leish4E-IP2 inhibits the cap-binding activity of LeishIF4E-1 and LeishIF4E-3. Furthermore, we show that transgenic parasites expressing a tagged version of Leish4E-IP2 also display reduced cap-binding activities of tested LeishIF4Es, and decreased global translation. Given its ability to bind more than a single LeishIF4E, we suggest that Leish4E-IP2 could serve as a broad-range repressor of Leishmania protein synthesis.
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Affiliation(s)
- Nitin Tupperwar
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Shimi Meleppattu
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA.,Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02138, USA
| | - Rohit Shrivastava
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Nofar Baron
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Ayelet Gilad
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA 02138, USA
| | - Mélissa Léger-Abraham
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, MA 02115, USA
| | - Michal Shapira
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva 84105, Israel
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30
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Juszkiewicz S, Slodkowicz G, Lin Z, Freire-Pritchett P, Peak-Chew SY, Hegde RS. Ribosome collisions trigger cis-acting feedback inhibition of translation initiation. eLife 2020; 9:e60038. [PMID: 32657267 PMCID: PMC7381030 DOI: 10.7554/elife.60038] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 07/10/2020] [Indexed: 12/19/2022] Open
Abstract
Translation of aberrant mRNAs can cause ribosomes to stall, leading to collisions with trailing ribosomes. Collided ribosomes are specifically recognised by ZNF598 to initiate protein and mRNA quality control pathways. Here we found using quantitative proteomics of collided ribosomes that EDF1 is a ZNF598-independent sensor of ribosome collisions. EDF1 stabilises GIGYF2 at collisions to inhibit translation initiation in cis via 4EHP. The GIGYF2 axis acts independently of the ZNF598 axis, but each pathway's output is more pronounced without the other. We propose that the widely conserved and highly abundant EDF1 monitors the transcriptome for excessive ribosome density, then triggers a GIGYF2-mediated response to locally and temporarily reduce ribosome loading. Only when collisions persist is translation abandoned to initiate ZNF598-dependent quality control. This tiered response to ribosome collisions would allow cells to dynamically tune translation rates while ensuring fidelity of the resulting protein products.
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Affiliation(s)
- Szymon Juszkiewicz
- MRC Laboratory of Molecular Biology, Francis Crick AvenueCambridgeUnited Kingdom
| | - Greg Slodkowicz
- MRC Laboratory of Molecular Biology, Francis Crick AvenueCambridgeUnited Kingdom
| | - Zhewang Lin
- MRC Laboratory of Molecular Biology, Francis Crick AvenueCambridgeUnited Kingdom
| | | | - Sew-Yeu Peak-Chew
- MRC Laboratory of Molecular Biology, Francis Crick AvenueCambridgeUnited Kingdom
| | - Ramanujan S Hegde
- MRC Laboratory of Molecular Biology, Francis Crick AvenueCambridgeUnited Kingdom
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31
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Abstract
The stage at which ribosomes are recruited to messenger RNAs (mRNAs) is an elaborate and highly regulated phase of protein synthesis. Upon completion of this step, a ribosome is positioned at an appropriate initiation codon and primed to synthesize the encoded polypeptide product. In most circumstances, this step commits the ribosome to translate the mRNA. We summarize the knowledge regarding the initiation factors implicated in this activity as well as review different mechanisms by which this process is conducted.
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Affiliation(s)
- Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada; , .,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3A 1A3, Canada.,Department of Oncology, McGill University, Montreal, Quebec H4A 3T2, Canada
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada; , .,Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3A 1A3, Canada
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32
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GIGYF1/2-Driven Cooperation between ZNF598 and TTP in Posttranscriptional Regulation of Inflammatory Signaling. Cell Rep 2020; 26:3511-3521.e4. [PMID: 30917308 DOI: 10.1016/j.celrep.2019.03.006] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 01/03/2019] [Accepted: 02/27/2019] [Indexed: 12/15/2022] Open
Abstract
Inflammatory signaling is restricted through degradation and the translational repression of cytokine mRNAs. A key factor in this regulation is tristetraprolin (TTP), an RNA-binding protein (RBP) that recruits RNA-destabilizing factors and the translation inhibitory complex 4EHP-GIGYF1/2 to AU-rich element (ARE)-containing mRNAs. Here, we show that the RBP ZNF598 contributes to the same regulatory module in a TTP-like manner. Similar to TTP, ZNF598 harbors three proline-rich motifs that bind the GYF domain of GIGYF1. RNA sequencing experiments showed that ZNF598 is required for the regulation of known TTP targets, including IL-8 and CSF2 mRNA. Furthermore, we demonstrate that ZNF598 binds to IL-8 mRNA, but not TNF mRNA. Collectively, our findings highlight that ZNF598 functions as an RBP that buffers the level of a range of mRNAs. We propose that ZNF598 is a TTP-like factor that can contribute to the regulation of the inflammatory potential of cytokine-producing cells.
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33
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Räsch F, Weber R, Izaurralde E, Igreja C. 4E-T-bound mRNAs are stored in a silenced and deadenylated form. Genes Dev 2020; 34:847-860. [PMID: 32354837 PMCID: PMC7263148 DOI: 10.1101/gad.336073.119] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 04/02/2020] [Indexed: 12/20/2022]
Abstract
Human 4E-T is an eIF4E-binding protein (4E-BP) present in processing (P)-bodies that represses translation and regulates decay of mRNAs destabilized by AU-rich elements and microRNAs (miRNAs). However, the underlying regulatory mechanisms are still unclear. Here, we show that upon mRNA binding 4E-T represses translation and promotes deadenylation via the recruitment of the CCR4-NOT deadenylase complex. The interaction with CCR4-NOT is mediated by previously uncharacterized sites in the middle region of 4E-T. Importantly, mRNA decapping and decay are inhibited by 4E-T and the deadenylated target is stored in a repressed form. Inhibition of mRNA decapping requires the interaction of 4E-T with the cap-binding proteins eIF4E/4EHP. We further show that regulation of decapping by 4E-T participates in mRNA repression by the miRNA effector protein TNRC6B and that 4E-T overexpression interferes with tristetraprolin (TTP)- and NOT1-mediated mRNA decay. Thus, we postulate that 4E-T modulates 5'-to-3' decay by swapping the fate of a deadenylated mRNA from complete degradation to storage. Our results provide insight into the mechanism of mRNA storage that controls localized translation and mRNA stability in P-bodies.
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Affiliation(s)
- Felix Räsch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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34
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Translation initiation factors GleIF4E2 and GleIF4A can interact directly with the components of the pre-initiation complex to facilitate translation initiation in Giardia lamblia. Mol Biochem Parasitol 2020; 236:111258. [DOI: 10.1016/j.molbiopara.2020.111258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 12/31/2019] [Accepted: 01/13/2020] [Indexed: 01/20/2023]
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35
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Ruscica V, Bawankar P, Peter D, Helms S, Igreja C, Izaurralde E. Direct role for the Drosophila GIGYF protein in 4EHP-mediated mRNA repression. Nucleic Acids Res 2020; 47:7035-7048. [PMID: 31114929 PMCID: PMC6648886 DOI: 10.1093/nar/gkz429] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 02/07/2023] Open
Abstract
The eIF4E-homologous protein (4EHP) is a translational repressor that competes with eIF4E for binding to the 5'-cap structure of specific mRNAs, to which it is recruited by protein factors such as the GRB10-interacting GYF (glycine-tyrosine-phenylalanine domain) proteins (GIGYF). Several experimental evidences suggest that GIGYF proteins are not merely facilitating 4EHP recruitment to transcripts but are actually required for the repressor activity of the complex. However, the underlying molecular mechanism is unknown. Here, we investigated the role of the uncharacterized Drosophila melanogaster (Dm) GIGYF protein in post-transcriptional mRNA regulation. We show that, when in complex with 4EHP, Dm GIGYF not only elicits translational repression but also promotes target mRNA decay via the recruitment of additional effector proteins. We identified the RNA helicase Me31B/DDX6, the decapping activator HPat and the CCR4-NOT deadenylase complex as binding partners of GIGYF proteins. Recruitment of Me31B and HPat via discrete binding motifs conserved among metazoan GIGYF proteins is required for downregulation of mRNA expression by the 4EHP-GIGYF complex. Our findings are consistent with a model in which GIGYF proteins additionally recruit decapping and deadenylation complexes to 4EHP-containing RNPs to induce translational repression and degradation of mRNA targets.
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Affiliation(s)
- Vincenzo Ruscica
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Praveen Bawankar
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.,Institute of Molecular Biology gGmbH, Ackermannweg 4, 55128 Mainz, Germany
| | - Daniel Peter
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany.,European Molecular Biology Laboratory, 71 avenue des Martyrs, CS 90181, 38042 Grenoble Cedex 9, France
| | - Sigrun Helms
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, D-72076 Tübingen, Germany
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36
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Communication Is Key: 5'-3' Interactions that Regulate mRNA Translation and Turnover. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1203:149-164. [PMID: 31811634 DOI: 10.1007/978-3-030-31434-7_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Most eukaryotic mRNAs maintain a 5' cap structure and 3' poly(A) tail, cis-acting elements that are often separated by thousands of nucleotides. Nevertheless, multiple paradigms exist where mRNA 5' and 3' termini interact with each other in order to regulate mRNA translation and turnover. mRNAs recruit translation initiation factors to their termini, which in turn physically interact with each other. This physical bridging of the mRNA termini is known as the "closed loop" model, with years of genetic and biochemical evidence supporting the functional synergy between the 5' cap and 3' poly(A) tail to enhance mRNA translation initiation. However, a number of examples exist of "non-canonical" 5'-3' communication for cellular and viral RNAs that lack 5' cap structures and/or poly(A) tails. Moreover, in several contexts, mRNA 5'-3' communication can function to repress translation. Overall, we detail how various mRNA 5'-3' interactions play important roles in posttranscriptional regulation, wherein depending on the protein factors involved can result in translational stimulation or repression.
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37
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Abstract
Leishmania parasites are the causative agents of a broad spectrum of diseases. The parasites migrate between sand-fly vectors and mammalian hosts, adapting to changing environments by driving a regulated program of gene expression, with translation regulation playing a key role. The leishmanias encode six different paralogs of eIF4E, the cap-binding translation initiation factor. Since these vary in function, expression profile, and assemblage, it is assumed that each is assigned a specific role throughout the life cycle. Using the CRISPR-Cas9 system for Leishmania, we generated a null mutant of LeishIF4E1, eliminating both alleles. Although the mutant cells were viable, their morphology was altered and their ability to synthesize the flagellum was impaired. Elimination of LeishIF4E1 affected their protein expression profile and decreased their ability to infect cultured macrophages. Restoring LeishIF4E1 expression restored the affected features. This study highlights the importance of LeishIF4E1 in diverse cellular events during the life cycle of Leishmania. Leishmania parasites cycle between sand-fly vectors and mammalian hosts, adapting to changing environmental conditions by driving a stage-specific program of gene expression, which is tightly regulated by translation processes. Leishmania encodes six eIF4E orthologs (LeishIF4Es) and five eIF4G candidates, forming different cap-binding complexes with potentially varying functions. Most LeishIF4E paralogs display temperature sensitivity in their cap-binding activity, except for LeishIF4E1, which maintains its cap-binding activity under all conditions. We used the CRISPR-Cas9 system to successfully generate a null mutant of LeishIF4E1 and examine how its elimination affected parasite physiology. Although the LeishIF4E1–/– null mutant was viable, its growth was impaired, in line with a reduction in global translation. As a result of the mutation, the null LeishIF4E1–/– mutant had a defective morphology, as the cells were round and unable to grow a normal flagellum. This was further emphasized when the LeishIF4E1–/– cells failed to develop the promastigote morphology once they shifted from conditions that generate axenic amastigotes (33°C, pH 5.5) back to neutral pH and 25°C, and they maintained their short flagellum and circular structure. Finally, the LeishIF4E1–/– null mutant displayed difficulty in infecting cultured macrophages. The morphological changes and reduced infectivity of the mutant may be related to differences in the proteomic profile of LeishIF4E1–/– cells from that of controls. All defects monitored in the LeishIF4E1–/– null mutant were reversed in the add-back strain, in which expression of LeishIF4E1 was reconstituted, establishing a strong link between the cellular defects and the absence of LeishIF4E1 expression. IMPORTANCELeishmania parasites are the causative agents of a broad spectrum of diseases. The parasites migrate between sand-fly vectors and mammalian hosts, adapting to changing environments by driving a regulated program of gene expression, with translation regulation playing a key role. The leishmanias encode six different paralogs of eIF4E, the cap-binding translation initiation factor. Since these vary in function, expression profile, and assemblage, it is assumed that each is assigned a specific role throughout the life cycle. Using the CRISPR-Cas9 system for Leishmania, we generated a null mutant of LeishIF4E1, eliminating both alleles. Although the mutant cells were viable, their morphology was altered and their ability to synthesize the flagellum was impaired. Elimination of LeishIF4E1 affected their protein expression profile and decreased their ability to infect cultured macrophages. Restoring LeishIF4E1 expression restored the affected features. This study highlights the importance of LeishIF4E1 in diverse cellular events during the life cycle of Leishmania.
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38
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Ronkina N, Shushakova N, Tiedje C, Yakovleva T, Tollenaere MAX, Scott A, Batth TS, Olsen JV, Helmke A, Bekker-Jensen SH, Clark AR, Kotlyarov A, Gaestel M. The Role of TTP Phosphorylation in the Regulation of Inflammatory Cytokine Production by MK2/3. THE JOURNAL OF IMMUNOLOGY 2019; 203:2291-2300. [PMID: 31527197 DOI: 10.4049/jimmunol.1801221] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2018] [Accepted: 08/20/2019] [Indexed: 01/05/2023]
Abstract
Tristetraprolin (TTP) is an RNA-binding protein and an essential factor of posttranscriptional repression of cytokine biosynthesis in macrophages. Its activity is temporally inhibited by LPS-induced p38MAPK/MAPKAPK2/3-mediated phosphorylation, leading to a rapid increase in cytokine expression. We compared TTP expression and cytokine production in mouse bone marrow-derived macrophages of different genotypes: wild type, MAPKAP kinase 2 (MK2) deletion (MK2 knockout [KO]), MK2/3 double deletion (MK2/3 double KO [DKO]), TTP-S52A-S178A (TTPaa) knock-in, as well as combined MK2 KO/TTPaa and MK2/3 DKO/TTPaa. The comparisons reveal that MK2/3 are the only LPS-induced kinases for S52 and S178 of TTP and the role of MK2 and MK3 in the regulation of TNF biosynthesis is not restricted to phosphorylation of TTP at S52/S178 but includes independent processes, which could involve other TTP phosphorylations (such as S316) or other substrates of MK2/3 or p38MAPK Furthermore, we found differences in the dependence of various cytokines on the cooperation between MK2/3 deletion and TTP mutation ex vivo. In the cecal ligation and puncture model of systemic inflammation, a dramatic decrease of cytokine production in MK2/3 DKO, TTPaa, and DKO/TTPaa mice compared with wild-type animals is observed, thus confirming the role of the MK2/3/TTP signaling axis in cytokine production also in vivo. These findings improve our understanding of this signaling axis and could be of future relevance in the treatment of inflammation.
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Affiliation(s)
- Natalia Ronkina
- Institute of Cell Biochemistry, Center of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Nelli Shushakova
- Division of Nephrology and Hypertension, Hannover Medical School, D-30625 Hannover, Germany.,Phenos GmbH, D-30625 Hannover, Germany
| | - Christopher Tiedje
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Tatiana Yakovleva
- Institute of Cell Biochemistry, Center of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Maxim A X Tollenaere
- Center for Healthy Aging, Department of Cellular and Molecular Medicine, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Aaron Scott
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, United Kingdom; and
| | - Tanveer Singh Batth
- Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Jesper Velgaard Olsen
- Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Alexandra Helmke
- Division of Nephrology and Hypertension, Hannover Medical School, D-30625 Hannover, Germany
| | - Simon Holst Bekker-Jensen
- Proteomics Program, Faculty of Health and Medical Sciences, Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Andrew R Clark
- Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, United Kingdom; and
| | - Alexey Kotlyarov
- Institute of Cell Biochemistry, Center of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Center of Biochemistry, Hannover Medical School, D-30625 Hannover, Germany;
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39
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Iakoucheva LM, Muotri AR, Sebat J. Getting to the Cores of Autism. Cell 2019; 178:1287-1298. [PMID: 31491383 PMCID: PMC7039308 DOI: 10.1016/j.cell.2019.07.037] [Citation(s) in RCA: 154] [Impact Index Per Article: 30.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 06/07/2019] [Accepted: 07/18/2019] [Indexed: 12/31/2022]
Abstract
The genetic architecture of autism spectrum disorder (ASD) is itself a diverse allelic spectrum that consists of rare de novo or inherited variants in hundreds of genes and common polygenic risk at thousands of loci. ASD susceptibility genes are interconnected at the level of transcriptional and protein networks, and many function as genetic regulators of neurodevelopment or synaptic proteins that regulate neural activity. So that the core underlying neuropathologies can be further elucidated, we emphasize the importance of first defining subtypes of ASD on the basis of the phenotypic signatures of genes in model systems and humans.
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Affiliation(s)
- Lilia M Iakoucheva
- University of California San Diego, Department of Psychiatry, La Jolla, CA 92093, USA
| | - Alysson R Muotri
- University of California San Diego, School of Medicine, Department of Cellular & Molecular Medicine, La Jolla, CA 92093, USA; University of California San Diego, School of Medicine, Department of Pediatrics/Rady Children's Hospital San Diego, La Jolla, CA 92093, USA; University of California San Diego, Kavli Institute for Brain and Mind, La Jolla, CA 92093, USA; Center for Academic Research and Training in Anthropogeny (CARTA), La Jolla, CA 92093, USA
| | - Jonathan Sebat
- University of California San Diego, Department of Psychiatry, La Jolla, CA 92093, USA; University of California San Diego, School of Medicine, Department of Cellular & Molecular Medicine, La Jolla, CA 92093, USA; University of California San Diego, Beyster Center for Psychiatric Genomics, La Jolla, CA 92093.
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40
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Peter D, Ruscica V, Bawankar P, Weber R, Helms S, Valkov E, Igreja C, Izaurralde E. Molecular basis for GIGYF-Me31B complex assembly in 4EHP-mediated translational repression. Genes Dev 2019; 33:1355-1360. [PMID: 31439631 PMCID: PMC6771390 DOI: 10.1101/gad.329219.119] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 07/18/2019] [Indexed: 11/24/2022]
Abstract
In this study, Peter et al. provide new insights into how GIGYF proteins function together with DDX6 in the regulation of mRNA expression. They used structural analysis, in vivo expression analysis, and biochemical assays to show that GIGYF contains a motif that is necessary and sufficient for direct interaction with Me31B/DDX6, and their findings advance our understanding of the mechanism and assembly of the 4EHP–GIGYF–DDX6 repressor complex. GIGYF (Grb10-interacting GYF [glycine–tyrosine–phenylalanine domain]) proteins coordinate with 4EHP (eIF4E [eukaryotic initiation factor 4E] homologous protein), the DEAD (Asp–Glu–Ala–Asp)-box helicase Me31B/DDX6, and mRNA-binding proteins to elicit transcript-specific repression. However, the underlying molecular mechanism remains unclear. Here, we report that GIGYF contains a motif necessary and sufficient for direct interaction with Me31B/DDX6. A 2.4 Å crystal structure of the GIGYF–Me31B complex reveals that this motif arranges into a coil connected to a β hairpin on binding to conserved hydrophobic patches on the Me31B RecA2 domain. Structure-guided mutants indicate that 4EHP–GIGYF–DDX6 complex assembly is required for tristetraprolin-mediated down-regulation of an AU-rich mRNA, thus revealing the molecular principles of translational repression.
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Affiliation(s)
- Daniel Peter
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany.,European Molecular Biology Laboratory, 38042 Grenoble Cedex 9, France
| | - Vincenzo Ruscica
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Praveen Bawankar
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany.,Institute of Molecular Biology, 55128 Mainz, Germany
| | - Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Sigrun Helms
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Eugene Valkov
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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41
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Amaya Ramirez CC, Hubbe P, Mandel N, Béthune J. 4EHP-independent repression of endogenous mRNAs by the RNA-binding protein GIGYF2. Nucleic Acids Res 2019; 46:5792-5808. [PMID: 29554310 PMCID: PMC6009589 DOI: 10.1093/nar/gky198] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 03/07/2018] [Indexed: 11/12/2022] Open
Abstract
Initially identified as a factor involved in tyrosine kinase receptor signaling, Grb10-interacting GYF protein 2 (GIGYF2) has later been shown to interact with the 5′ cap-binding protein 4EHP as part of a translation repression complex, and to mediate post-transcriptional repression of tethered reporter mRNAs. A current model proposes that GIGYF2 is indirectly recruited to mRNAs by specific RNA-binding proteins (RBPs) leading to translation repression through its association with 4EHP. Accordingly, we recently observed that GIGYF2 also interacts with the miRNA-induced silencing complex and probably modulates its translation repression activity. Here we have further investigated how GIGYF2 represses mRNA function. In a tethering reporter assay, we identify three independent domains of GIGYF2 with repressive activity. In this assay, GIGYF2-mediated repression is independent of 4EHP but largely dependent on the CCR4/NOT complex that GIGYF2 recruits through multiple interfaces. Importantly, we show that GIGYF2 is an RBP and identify for the first time endogenous mRNA targets that recapitulate 4EHP-independent repression. Altogether, we propose that GIGYF2 has two distinct mechanisms of repression: one depends on 4EHP binding and mainly affects translation; the other is 4EHP-independent and involves the CCR4/NOT complex and its deadenylation activity.
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Affiliation(s)
- Cinthia C Amaya Ramirez
- CellNetworks Junior Research Group Posttranscriptional Regulation of mRNA Expression and Localization, Heidelberg University, D-69120 Heidelberg, Germany.,Biochemistry Center, Heidelberg University, D-69120 Heidelberg, Germany
| | - Petra Hubbe
- CellNetworks Junior Research Group Posttranscriptional Regulation of mRNA Expression and Localization, Heidelberg University, D-69120 Heidelberg, Germany.,Biochemistry Center, Heidelberg University, D-69120 Heidelberg, Germany
| | - Nicolas Mandel
- CellNetworks Junior Research Group Posttranscriptional Regulation of mRNA Expression and Localization, Heidelberg University, D-69120 Heidelberg, Germany.,Biochemistry Center, Heidelberg University, D-69120 Heidelberg, Germany
| | - Julien Béthune
- CellNetworks Junior Research Group Posttranscriptional Regulation of mRNA Expression and Localization, Heidelberg University, D-69120 Heidelberg, Germany.,Biochemistry Center, Heidelberg University, D-69120 Heidelberg, Germany
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42
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Terrao M, Marucha KK, Mugo E, Droll D, Minia I, Egler F, Braun J, Clayton C. The suppressive cap-binding complex factor 4EIP is required for normal differentiation. Nucleic Acids Res 2019; 46:8993-9010. [PMID: 30124912 PMCID: PMC6158607 DOI: 10.1093/nar/gky733] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 08/01/2018] [Indexed: 12/27/2022] Open
Abstract
Trypanosoma brucei live in mammals as bloodstream forms and in the Tsetse midgut as procyclic forms. Differentiation from one form to the other proceeds via a growth-arrested stumpy form with low messenger RNA (mRNA) content and translation. The parasites have six eIF4Es and five eIF4Gs. EIF4E1 pairs with the mRNA-binding protein 4EIP but not with any EIF4G. EIF4E1 and 4EIP each inhibit expression when tethered to a reporter mRNA, but while tethered EIF4E1 suppresses only when 4EIP is present, suppression by tethered 4EIP does not require the interaction with EIF4E1. In growing bloodstream forms, 4EIP is preferentially associated with unstable mRNAs. Bloodstream- or procyclic-form trypanosomes lacking 4EIP have only a marginal growth disadvantage. Bloodstream forms without 4EIP are, however, defective in translation suppression during stumpy-form differentiation and cannot subsequently convert to growing procyclic forms. Intriguingly, the differentiation defect can be complemented by a truncated 4EIP that does not interact with EIF4E1. In contrast, bloodstream forms lacking EIF4E1 have a growth defect, stumpy formation seems normal, but they appear unable to grow as procyclic forms. We suggest that 4EIP and EIF4E1 fine-tune mRNA levels in growing cells, and that 4EIP contributes to translation suppression during differentiation to the stumpy form.
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Affiliation(s)
- Monica Terrao
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Kevin K Marucha
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Elisha Mugo
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Dorothea Droll
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Igor Minia
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Franziska Egler
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Johanna Braun
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
| | - Christine Clayton
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, D-69120 Heidelberg, Germany
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43
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Volpon L, Osborne MJ, Borden KL. Biochemical and Structural Insights into the Eukaryotic Translation Initiation Factor eIF4E. Curr Protein Pept Sci 2019; 20:525-535. [DOI: 10.2174/1389203720666190110142438] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 11/26/2018] [Accepted: 01/04/2019] [Indexed: 12/18/2022]
Abstract
A major question in cell and cancer biology is concerned with understanding the flow of
information from gene to protein. Indeed, many studies indicate that the proteome can be decoupled
from the transcriptome. A major source of this decoupling is post-transcriptional regulation. The eukaryotic
translation initiation factor eIF4E serves as an excellent example of a protein that can modulate
the proteome at the post-transcriptional level. eIF4E is elevated in many cancers thus highlighting
the relevance of this mode of control to biology. In this review, we provide a brief overview of various
functions of eIF4E in RNA metabolism e.g. in nuclear-cytoplasmic RNA export, translation,
RNA stability and/or sequestration. We focus on the modalities of eIF4E regulation at the biochemical
and particularly structural level. In this instance, we describe not only the importance for the m7Gcap
eIF4E interaction but also of recently discovered non-traditional RNA-eIF4E interactions as well
as cap-independent activities of eIF4E. Further, we describe several distinct structural modalities used
by the cell and some viruses to regulate or co-opt eIF4E, substantially extending the types of proteins
that can regulate eIF4E from the traditional eIF4E-binding proteins (e.g. 4E-BP1 and eIF4G). Finally,
we provide an overview of the results of targeting eIF4E activity in the clinic.
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Affiliation(s)
- Laurent Volpon
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
| | - Michael J. Osborne
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
| | - Katherine L.B. Borden
- Institute for Research in Immunology and Cancer (IRIC), Department of Pathology and Cell Biology, Universite de Montreal, Pavillion Marcelle-Coutu, Chemin Polytechnique, Montreal, Quebec, Canada
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44
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Coutinho de Oliveira L, Volpon L, Osborne MJ, Borden KLB. Chemical shift assignment of the viral protein genome-linked (VPg) from potato virus Y. BIOMOLECULAR NMR ASSIGNMENTS 2019; 13:9-13. [PMID: 30242622 PMCID: PMC6428624 DOI: 10.1007/s12104-018-9842-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 09/14/2018] [Indexed: 06/08/2023]
Abstract
The dysregulation of translation contributes to many pathogenic conditions in humans. Discovering new translational mechanisms is important to understanding the diversity of this process and its potential mechanisms. Such mechanisms can be initially observed in viruses. With this in mind, we studied the viral protein genome-linked VPg factor from the largest genus of plant viruses. Studies in plants show that VPg binds to the eukaryotic translation initiation factor eIF4E for translation of viral RNAs. VPg contains no known eIF4E binding motifs and no sequence homology to any known proteins. Thus, as a first step in understanding the structural basis of this interaction, we carried out NMR assignments of the VPg from the potato virus Y potyvirus protein.
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Affiliation(s)
- Luciana Coutinho de Oliveira
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Laurent Volpon
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Michael J Osborne
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada
| | - Katherine L B Borden
- Department of Pathology and Cell Biology, Institute of Research in Immunology and Cancer (IRIC), Université de Montréal, Pavilion Marcelle-Coutu, Chemin Polytechnique, Montreal, QC, Canada.
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A threonyl-tRNA synthetase-mediated translation initiation machinery. Nat Commun 2019; 10:1357. [PMID: 30902983 PMCID: PMC6430810 DOI: 10.1038/s41467-019-09086-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 02/13/2019] [Indexed: 12/13/2022] Open
Abstract
A fundamental question in biology is how vertebrates evolved and differ from invertebrates, and little is known about differences in the regulation of translation in the two systems. Herein, we identify a threonyl-tRNA synthetase (TRS)-mediated translation initiation machinery that specifically interacts with eIF4E homologous protein, and forms machinery that is structurally analogous to the eIF4F-mediated translation initiation machinery via the recruitment of other translation initiation components. Biochemical and RNA immunoprecipitation analyses coupled to sequencing suggest that this machinery emerged as a gain-of-function event in the vertebrate lineage, and it positively regulates the translation of mRNAs required for vertebrate development. Collectively, our findings demonstrate that TRS evolved to regulate vertebrate translation initiation via its dual role as a scaffold for the assembly of initiation components and as a selector of target mRNAs. This work highlights the functional significance of aminoacyl-tRNA synthetases in the emergence and control of higher order organisms. The initiation of translation is a highly regulated process that contributes to specific gene expression programs. Here the authors find that, in vertebrate, threonyl-tRNA synthetase (TRS) can act as a scaffold for the initiation machinery to stimulate the translation of a specific set of mRNAs.
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46
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Duchaine TF, Fabian MR. Mechanistic Insights into MicroRNA-Mediated Gene Silencing. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a032771. [PMID: 29959194 DOI: 10.1101/cshperspect.a032771] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
MicroRNAs (miRNAs) posttranscriptionally regulate gene expression by repressing protein synthesis and exert a broad influence over development, physiology, adaptation, and disease. Over the past two decades, great strides have been made toward elucidating how miRNAs go about shutting down messenger RNA (mRNA) translation and promoting mRNA decay.
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Affiliation(s)
- Thomas F Duchaine
- Department of Biochemistry & Goodman Cancer Research Centre, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Marc R Fabian
- Department of Oncology, McGill University, Montreal, Quebec H3G 1Y6, Canada.,Lady Davis Institute, Jewish General Hospital, Montreal, Quebec H3T 1E2, Canada
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47
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Keskeny C, Raisch T, Sgromo A, Igreja C, Bhandari D, Weichenrieder O, Izaurralde E. A conserved CAF40-binding motif in metazoan NOT4 mediates association with the CCR4-NOT complex. Genes Dev 2019; 33:236-252. [PMID: 30692204 PMCID: PMC6362812 DOI: 10.1101/gad.320952.118] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/10/2018] [Indexed: 11/25/2022]
Abstract
The multisubunit CCR4-NOT mRNA deadenylase complex plays important roles in the posttranscriptional regulation of gene expression. The NOT4 E3 ubiquitin ligase is a stable component of the CCR4-NOT complex in yeast but does not copurify with the human or Drosophila melanogaster complex. Here we show that the C-terminal regions of human and D. melanogaster NOT4 contain a conserved sequence motif that directly binds the CAF40 subunit of the CCR4-NOT complex (CAF40-binding motif [CBM]). In addition, nonconserved sequences flanking the CBM also contact other subunits of the complex. Crystal structures of the CBM-CAF40 complex reveal a mutually exclusive binding surface for NOT4 and Roquin or Bag of marbles mRNA regulatory proteins. Furthermore, CAF40 depletion or structure-guided mutagenesis to disrupt the NOT4-CAF40 interaction impairs the ability of NOT4 to elicit decay of tethered reporter mRNAs in cells. Together with additional sequence analyses, our results reveal the molecular basis for the association of metazoan NOT4 with the CCR4-NOT complex and show that it deviates substantially from yeast. They mark the NOT4 ubiquitin ligase as an ancient but nonconstitutive cofactor of the CCR4-NOT deadenylase with potential recruitment and/or effector functions.
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Affiliation(s)
- Csilla Keskeny
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Tobias Raisch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Annamaria Sgromo
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Dipankar Bhandari
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Oliver Weichenrieder
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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48
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Zhou T, Ma Y, Tang J, Guo F, Dong M, Wei Q. Modulation of IGF1R Signaling Pathway by GIGYF1 in High Glucose-Induced SHSY-5Y Cells. DNA Cell Biol 2018; 37:1044-1054. [PMID: 30376373 DOI: 10.1089/dna.2018.4336] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Affiliation(s)
- Ting Zhou
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuefei Ma
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Juan Tang
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Fengqi Guo
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Mingxia Dong
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Qianping Wei
- Department of Geriatrics, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
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49
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Chen YC, Chang YW, Huang YS. Dysregulated Translation in Neurodevelopmental Disorders: An Overview of Autism-Risk Genes Involved in Translation. Dev Neurobiol 2018; 79:60-74. [PMID: 30430754 DOI: 10.1002/dneu.22653] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Revised: 09/17/2018] [Accepted: 10/25/2018] [Indexed: 01/08/2023]
Abstract
Regulated local translation-whereby specific mRNAs are transported and localized in subcellular domains where they are translated in response to regional signals-allows for remote control of gene expression to concentrate proteins in subcellular compartments. Neurons are highly polarized cells with unique features favoring local control for axonal pathfinding and synaptic plasticity, which are key processes involved in constructing functional circuits in the developing brain. Neurodevelopmental disorders are caused by genetic or environmental factors that disturb the nervous system's development during prenatal and early childhood periods. The growing list of genetic mutations that affect mRNA translation raises the question of whether aberrant translatomes in individuals with neurodevelopmental disorders share common molecular features underlying their stereotypical phenotypes and, vice versa, cause a certain degree of phenotypic heterogeneity. Here, we briefly give an overview of the role of local translation during neuronal development. We take the autism-risk gene list and discuss the molecules that (perhaps) are involved in mRNA transport and translation. Both exaggerated and suppressed translation caused by mutations in those genes have been identified or suggested. Finally, we discuss some proof-of-principle regimens for use in autism mouse models to correct dysregulated translation.
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Affiliation(s)
- Yan-Chu Chen
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Yu-Wei Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
| | - Yi-Shuian Huang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, 11529, Taiwan
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50
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Cencic R, Pelletier J. A cautionary note on the use of cap analogue affinity resins. Anal Biochem 2018; 560:24-29. [PMID: 30193929 DOI: 10.1016/j.ab.2018.09.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Revised: 09/02/2018] [Accepted: 09/03/2018] [Indexed: 10/28/2022]
Abstract
All cellular cytoplasmic mRNAs are capped at their 5' ends with an m7GpppN group. Several proteins that mediate cap function have been identified by cap affinity purification, enabling their characterization in a number of biological processes. Among these, eukaryotic initiation factor (eIF) 4E is the best characterized and plays a critical role in regulating ribosome recruitment to mRNAs during translation initiation. Cap affinity chromatography is often used to identify eIF4E-interacting proteins, which could play critical roles in molding the eIF4E-interactome and impacting on eIF4E-directed translation. Here we address how improper implementation of this technology can lead to false conclusions and provide recommendations to ensure correct interpretation of data obtained by this approach.
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Affiliation(s)
- Regina Cencic
- Department of Biochemistry, McGill University, Montreal, Quebec, H3G 1Y6, Canada
| | - Jerry Pelletier
- Department of Biochemistry, McGill University, Montreal, Quebec, H3G 1Y6, Canada; Rosalind and Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec, H3G 1Y6, Canada; Department of Oncology, McGill University, Montreal, Quebec, H3G 1Y6, Canada.
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