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González-Sánchez AM, Castellanos-Silva EA, Díaz-Figueroa G, Cate JHD. JUN mRNA translation regulation is mediated by multiple 5' UTR and start codon features. PLoS One 2024; 19:e0299779. [PMID: 38483896 PMCID: PMC10939236 DOI: 10.1371/journal.pone.0299779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/14/2024] [Indexed: 03/17/2024] Open
Abstract
Regulation of mRNA translation by eukaryotic initiation factors (eIFs) is crucial for cell survival. In humans, eIF3 stimulates translation of the JUN mRNA which encodes the transcription factor JUN, an oncogenic transcription factor involved in cell cycle progression, apoptosis, and cell proliferation. Previous studies revealed that eIF3 activates translation of the JUN mRNA by interacting with a stem loop in the 5' untranslated region (5' UTR) and with the 5' -7-methylguanosine cap structure. In addition to its interaction site with eIF3, the JUN 5' UTR is nearly one kilobase in length, and has a high degree of secondary structure, high GC content, and an upstream start codon (uAUG). This motivated us to explore the complexity of JUN mRNA translation regulation in human cells. Here we find that JUN translation is regulated in a sequence and structure-dependent manner in regions adjacent to the eIF3-interacting site in the JUN 5' UTR. Furthermore, we identify contributions of an additional initiation factor, eIF4A, in JUN regulation. We show that enhancing the interaction of eIF4A with JUN by using the compound Rocaglamide A (RocA) represses JUN translation. We also find that both the upstream AUG (uAUG) and the main AUG (mAUG) contribute to JUN translation and that they are conserved throughout vertebrates. Our results reveal additional layers of regulation for JUN translation and show the potential of JUN as a model transcript for understanding multiple interacting modes of translation regulation.
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Affiliation(s)
- Angélica M. González-Sánchez
- Comparative Biochemistry Graduate Program, University of California, Berkeley, Berkeley, CA, United States of America
| | - Eimy A. Castellanos-Silva
- Department of Biochemistry and Molecular Biology, University of California, Davis, Davis, CA, United States of America
| | - Gabriela Díaz-Figueroa
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States of America
| | - Jamie H. D. Cate
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States of America
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2
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Xiao Y, Wang R, Han X, Wang W, Liang A. The Deficiency of Hypusinated eIF5A Decreases the Putrescine/Spermidine Ratio and Inhibits +1 Programmed Ribosomal Frameshifting during the Translation of Ty1 Retrotransposon in Saccharomyces cerevisiae. Int J Mol Sci 2024; 25:1766. [PMID: 38339043 PMCID: PMC10855120 DOI: 10.3390/ijms25031766] [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: 11/29/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Programmed ribosomal frameshifting (PRF) exists in all branches of life that regulate gene expression at the translational level. The eukaryotic translation initiation factor 5A (eIF5A) is a highly conserved protein essential in all eukaryotes. It is identified initially as an initiation factor and functions broadly in translation elongation and termination. The hypusination of eIF5A is specifically required for +1 PRF at the shifty site derived from the ornithine decarboxylase antizyme 1 (OAZ1) in Saccharomyces cerevisiae. However, whether the regulation of +1 PRF by yeast eIF5A is universal remains unknown. Here, we found that Sc-eIF5A depletion decreased the putrescine/spermidine ratio. The re-introduction of Sc-eIF5A in yeast eIF5A mutants recovered the putrescine/spermidine ratio. In addition, the Sc-eIF5A depletion decreases +1 PRF during the decoding of Ty1 retrotransposon mRNA, but has no effect on -1 PRF during the decoding of L-A virus mRNA. The re-introduction of Sc-eIF5A in yeast eIF5A mutants restored the +1 PRF rate of Ty1. The inhibition of the hypusine modification of yeast eIF5A by GC7 treatment or by mutating the hypusination site Lys to Arg caused decreases of +1 PRF rates in the Ty1 retrotransposon. Furthermore, mutational studies of the Ty1 frameshifting element support a model where the efficient removal of ribosomal subunits at the first Ty1 frame 0 stop codon is required for the frameshifting of trailing ribosomes. This dependency is likely due to the unique position of the frame 0 stop codon distance from the slippery sequence of Ty1. The results showed that eIF5A is a trans-regulator of +1 PRF for Ty1 retrotransposon and could function universally in yeast.
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Affiliation(s)
- Yu Xiao
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Ruanlin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Xiaxia Han
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Wei Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Aihua Liang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
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3
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González-Sánchez AM, Castellanos-Silva EA, Díaz-Figueroa G, Cate JHD. JUN mRNA Translation Regulation is Mediated by Multiple 5' UTR and Start Codon Features. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.17.567602. [PMID: 38014201 PMCID: PMC10680820 DOI: 10.1101/2023.11.17.567602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Regulation of mRNA translation by eukaryotic initiation factors (eIFs) is crucial for cell survival. In humans, eIF3 stimulates translation of the JUN mRNA which encodes the transcription factor JUN, an oncogenic transcription factor involved in cell cycle progression, apoptosis, and cell proliferation. Previous studies revealed that eIF3 activates translation of the JUN mRNA by interacting with a stem loop in the 5' untranslated region (5' UTR) and with the 5'-7-methylguanosine cap structure. In addition to its interaction site with eIF3, the JUN 5' UTR is nearly one kilobase in length, and has a high degree of secondary structure, high GC content, and an upstream start codon (uAUG). This motivated us to explore the complexity of JUN mRNA translation regulation in human cells. Here we find that JUN translation is regulated in a sequence and structure-dependent manner in regions adjacent to the eIF3-interacting site in the JUN 5' UTR. Furthermore, we identify contributions of an additional initiation factor, eIF4A, in JUN regulation. We show that enhancing the interaction of eIF4A with JUN by using the compound Rocaglamide A (RocA) represses JUN translation. We also find that both the upstream AUG (uAUG) and the main AUG (mAUG) contribute to JUN translation and that they are conserved throughout vertebrates. Our results reveal additional layers of regulation for JUN translation and show the potential of JUN as a model transcript for understanding multiple interacting modes of translation regulation.
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Affiliation(s)
| | - Eimy A Castellanos-Silva
- University of California, Davis, Department of Biochemistry and Molecular Biology, Davis, CA, USA
| | - Gabriela Díaz-Figueroa
- University of California, Berkeley, Department of Molecular and Cell Biology, Berkeley, CA, USA
| | - Jamie H D Cate
- University of California, Berkeley, Department of Molecular and Cell Biology, Berkeley, CA, USA
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4
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Petroni E, Esnault C, Tetreault D, Dale RK, Storz G, Adams PP. Extensive diversity in RNA termination and regulation revealed by transcriptome mapping for the Lyme pathogen Borrelia burgdorferi. Nat Commun 2023; 14:3931. [PMID: 37402717 DOI: 10.1038/s41467-023-39576-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Accepted: 06/16/2023] [Indexed: 07/06/2023] Open
Abstract
Transcription termination is an essential and dynamic process that can tune gene expression in response to diverse molecular signals. Yet, the genomic positions, molecular mechanisms, and regulatory consequences of termination have only been studied thoroughly in model bacteria. Here, we use several RNA-seq approaches to map RNA ends for the transcriptome of the spirochete Borrelia burgdorferi - the etiological agent of Lyme disease. We identify complex gene arrangements and operons, untranslated regions and small RNAs. We predict intrinsic terminators and experimentally test examples of Rho-dependent transcription termination. Remarkably, 63% of RNA 3' ends map upstream of or internal to open reading frames (ORFs), including genes involved in the unique infectious cycle of B. burgdorferi. We suggest these RNAs result from premature termination, processing and regulatory events such as cis-acting regulation. Furthermore, the polyamine spermidine globally influences the generation of truncated mRNAs. Collectively, our findings provide insights into transcription termination and uncover an abundance of potential RNA regulators in B. burgdorferi.
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Affiliation(s)
- Emily Petroni
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Caroline Esnault
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Daniel Tetreault
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Ryan K Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA
| | - Philip P Adams
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, 20892, USA.
- Postdoctoral Research Associate Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD, 20892, USA.
- Independent Research Scholar Program, Intramural Research Program, National Institutes of Health, Bethesda, MD, 20892, USA.
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5
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Jian H, Wen S, Liu R, Zhang W, Li Z, Chen W, Zhou Y, Khassanov V, Mahmoud AMA, Wang J, Lyu D. Dynamic Translational Landscape Revealed by Genome-Wide Ribosome Profiling under Drought and Heat Stress in Potato. PLANTS (BASEL, SWITZERLAND) 2023; 12:2232. [PMID: 37375858 DOI: 10.3390/plants12122232] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/02/2023] [Accepted: 06/02/2023] [Indexed: 06/29/2023]
Abstract
The yield and quality of potatoes, an important staple crop, are seriously threatened by high temperature and drought stress. In order to deal with this adverse environment, plants have evolved a series of response mechanisms. However, the molecular mechanism of potato's response to environmental changes at the translational level is still unclear. In this study, we performed transcriptome- and ribosome-profiling assays with potato seedlings growing under normal, drought, and high-temperature conditions to reveal the dynamic translational landscapes for the first time. The translational efficiency was significantly affected by drought and heat stress in potato. A relatively high correlation (0.88 and 0.82 for drought and heat stress, respectively) of the fold changes of gene expression was observed between the transcriptional level and translational level globally based on the ribosome-profiling and RNA-seq data. However, only 41.58% and 27.69% of the different expressed genes were shared by transcription and translation in drought and heat stress, respectively, suggesting that the transcription or translation process can be changed independently. In total, the translational efficiency of 151 (83 and 68 for drought and heat, respectively) genes was significantly changed. In addition, sequence features, including GC content, sequence length, and normalized minimal free energy, significantly affected the translational efficiencies of genes. In addition, 28,490 upstream open reading frames (uORFs) were detected on 6463 genes, with an average of 4.4 uORFs per gene and a median length of 100 bp. These uORFs significantly affected the translational efficiency of downstream major open reading frames (mORFs). These results provide new information and directions for analyzing the molecular regulatory network of potato seedlings in response to drought and heat stress.
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Affiliation(s)
- Hongju Jian
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
| | - Shiqi Wen
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Rongrong Liu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Wenzhe Zhang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Ziyan Li
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Weixi Chen
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
| | - Yonghong Zhou
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
| | - Vadim Khassanov
- Department of Plant Protection and Quarantine, Faculty of Agronomy, S. Seifullin Kazakh Agrotechnical University, Zhenis Avenue, 010011 Astana, Kazakhstan
| | - Ahmed M A Mahmoud
- Department of Vegetable Crops, Faculty of Agriculture, Cairo University, Giza 12613, Egypt
| | - Jichun Wang
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
| | - Dianqiu Lyu
- College of Agronomy and Biotechnology, Southwest University, Chongqing 400715, China
- State Cultivation Base of Crop Stress Biology for Southern Mountainous Land of Southwest University, Chongqing 400715, China
- Chongqing Key Laboratory of Biology and Genetic Breeding for Tuber and Root Crops, Chongqing 400715, China
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6
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Petroni E, Esnault C, Tetreault D, Dale RK, Storz G, Adams PP. Extensive diversity in RNA termination and regulation revealed by transcriptome mapping for the Lyme pathogen B. burgdorferi. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.04.522626. [PMID: 36712141 PMCID: PMC9881889 DOI: 10.1101/2023.01.04.522626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Transcription termination is an essential and dynamic process that can tune gene expression in response to diverse molecular signals. Yet, the genomic positions, molecular mechanisms, and regulatory consequences of termination have only been studied thoroughly in model bacteria. We employed complementary RNA-seq approaches to map RNA ends for the transcriptome of the spirochete Borrelia burgdorferi - the etiological agent of Lyme disease. By systematically mapping B. burgdorferi RNA ends at single nucleotide resolution, we delineated complex gene arrangements and operons and mapped untranslated regions (UTRs) and small RNAs (sRNAs). We experimentally tested modes of B. burgdorferi transcription termination and compared our findings to observations in E. coli , P. aeruginosa , and B. subtilis . We discovered 63% of B. burgdorferi RNA 3' ends map upstream or internal to open reading frames (ORFs), suggesting novel mechanisms of regulation. Northern analysis confirmed the presence of stable 5' derived RNAs from mRNAs encoding gene products involved in the unique infectious cycle of B. burgdorferi . We suggest these RNAs resulted from premature termination and regulatory events, including forms of cis- acting regulation. For example, we documented that the polyamine spermidine globally influences the generation of truncated mRNAs. In one case, we showed that high spermidine concentrations increased levels of RNA fragments derived from an mRNA encoding a spermidine import system, with a concomitant decrease in levels of the full- length mRNA. Collectively, our findings revealed new insight into transcription termination and uncovered an abundance of potential RNA regulators.
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Affiliation(s)
- Emily Petroni
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Caroline Esnault
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Daniel Tetreault
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Ryan K. Dale
- Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Gisela Storz
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | - Philip P. Adams
- Division of Molecular and Cellular Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA.,Postdoctoral Research Associate Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, MD 20892, USA.,Independent Research Scholar Program, Intramural Research Program, National Institutes of Health, Bethesda, MD 20892, USA.,correspondence:
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7
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Hiragori Y, Takahashi H, Karino T, Kaido A, Hayashi N, Sasaki S, Nakao K, Motomura T, Yamashita Y, Naito S, Onouchi H. Genome-wide identification of Arabidopsis non-AUG-initiated upstream ORFs with evolutionarily conserved regulatory sequences that control protein expression levels. PLANT MOLECULAR BIOLOGY 2023; 111:37-55. [PMID: 36044152 DOI: 10.1007/s11103-022-01309-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
This study identified four novel regulatory non-AUG-initiated upstream ORFs (uORFs) with evolutionarily conserved sequences in Arabidopsis and elucidated the mechanism by which a non-AUG-initiated uORF promotes main ORF translation. Upstream open reading frames (uORFs) are short ORFs found in the 5'-untranslated regions (5'-UTRs) of eukaryotic transcripts and can influence the translation of protein-coding main ORFs (mORFs). Recent genome-wide ribosome profiling studies have revealed that hundreds or thousands of uORFs initiate translation at non-AUG start codons. However, the physiological significance of these non-AUG uORFs has so far been demonstrated for only a few of them. In this study, to identify physiologically important regulatory non-AUG uORFs in Arabidopsis, we took an approach that combined bioinformatics and experimental analysis. Since physiologically important non-AUG uORFs are likely to be conserved across species, we first searched the Arabidopsis genome for non-AUG-initiated uORFs with evolutionarily conserved sequences. Then, we examined the effects of the conserved non-AUG uORFs on the expression of the downstream mORFs using transient expression assays. As a result, three inhibitory and one promotive non-AUG uORFs were identified. Among the inhibitory non-AUG uORFs, two exerted repressive effects on mORF expression in an amino acid sequence-dependent manner. These two non-AUG uORFs are likely to encode regulatory peptides that cause ribosome stalling, thereby enhancing their repressive effects. In contrast, one of the identified regulatory non-AUG uORFs promoted mORF expression by alleviating the inhibitory effect of a downstream AUG-initiated uORF. These findings provide insights into the mechanisms that enable non-AUG uORFs to play regulatory roles despite their low translation initiation efficiencies.
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Affiliation(s)
- Yuta Hiragori
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Hiro Takahashi
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, 920-1192, Japan
- Graduate School of Horticulture, Chiba University, Matsudo, 271-8510, Japan
| | - Taihei Karino
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Atsushi Kaido
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Noriya Hayashi
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Shun Sasaki
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Kodai Nakao
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Taichiro Motomura
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Yui Yamashita
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Satoshi Naito
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
- Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Hitoshi Onouchi
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
- Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
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8
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Antonov IV, O’Loughlin S, Gorohovski AN, O’Connor PB, Baranov PV, Atkins JF. Streptomyces rare codon UUA: from features associated with 2 adpA related locations to candidate phage regulatory translational bypassing. RNA Biol 2023; 20:926-942. [PMID: 37968863 PMCID: PMC10732093 DOI: 10.1080/15476286.2023.2270812] [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: 11/17/2022] [Accepted: 10/02/2023] [Indexed: 11/17/2023] Open
Abstract
In Streptomyces species, the cell cycle involves a switch from an early and vegetative state to a later phase where secondary products including antibiotics are synthesized, aerial hyphae form and sporulation occurs. AdpA, which has two domains, activates the expression of numerous genes involved in the switch from the vegetative growth phase. The adpA mRNA of many Streptomyces species has a UUA codon in a linker region between 5' sequence encoding one domain and 3' sequence encoding its other and C-terminal domain. UUA codons are exceptionally rare in Streptomyces, and its functional cognate tRNA is not present in a fully modified and acylated form, in the early and vegetative phase of the cell cycle though it is aminoacylated later. Here, we report candidate recoding signals that may influence decoding of the linker region UUA. Additionally, a short ORF 5' of the main ORF has been identified with a GUG at, or near, its 5' end and an in-frame UUA near its 3' end. The latter is commonly 5 nucleotides 5' of the main ORF start. Ribosome profiling data show translation of that 5' region. Ten years ago, UUA-mediated translational bypassing was proposed as a sensor by a Streptomyces phage of its host's cell cycle stage and an effector of its lytic/lysogeny switch. We provide the first experimental evidence supportive of this proposal.
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Affiliation(s)
- Ivan V. Antonov
- Russian Academy of Science, Institute of Bioengineering, Research Center of Biotechnology, Moscow, Russia
- Laboratory of Bioinformatics, Faculty of Computer Science, National Research University Higher School of Economics, Moscow, Russia
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Sinéad O’Loughlin
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Alessandro N. Gorohovski
- Russian Academy of Science, Institute of Bioengineering, Research Center of Biotechnology, Moscow, Russia
- Structural Biology and BioComputing Program, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | | | - Pavel V. Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - John F. Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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9
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Irajizad E, Fahrmann JF, Long JP, Vykoukal J, Kobayashi M, Capello M, Yu CY, Cai Y, Hsiao FC, Patel N, Park S, Peng Q, Dennison JB, Kato T, Tai MC, Taguchi A, Kadara H, Wistuba II, Katayama H, Do KA, Hanash SM, Ostrin EJ. A Comprehensive Search of Non-Canonical Proteins in Non-Small Cell Lung Cancer and Their Impact on the Immune Response. Int J Mol Sci 2022; 23:ijms23168933. [PMID: 36012199 PMCID: PMC9409146 DOI: 10.3390/ijms23168933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/05/2022] [Accepted: 08/08/2022] [Indexed: 12/02/2022] Open
Abstract
There is substantial interest in mining neoantigens for cancer applications. Non-canonical proteins resulting from frameshift mutations have been identified as neoantigens in cancer. We investigated the landscape of non-canonical proteins in non-small cell lung cancer (NSCLC) and their induced immune response in the form of autoantibodies. A database of cryptoproteins was computationally constructed and comprised all alternate open reading frames (altORFs) and ORFs identified in pseudogenes, noncoding RNAs, and untranslated regions of mRNAs that did not align with known canonical proteins. Proteomic profiles of seventeen lung adenocarcinoma (LUAD) cell lines were searched to evaluate the occurrence of cryptoproteins. To assess the immunogenicity, immunoglobulin (Ig)-bound cryptoproteins in plasmas were profiled by mass spectrometry. The specimen set consisted of plasmas from 30 newly diagnosed NSCLC cases, pre-diagnostic plasmas from 51 NSCLC cases, and 102 control plasmas. An analysis of LUAD cell lines identified 420 cryptoproteins. Plasma Ig-bound analyses revealed 90 cryptoproteins uniquely found in cases and 14 cryptoproteins that had a fold-change >2 compared to controls. In pre-diagnostic samples, 17 Ig-bound cryptoproteins yielded an odds ratio ≥2. Eight Ig-bound cryptoproteins were elevated in both pre-diagnostic and newly diagnosed cases compared to controls. Cryptoproteins represent a class of neoantigens that induce an autoantibody response in NSCLC.
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Affiliation(s)
- Ehsan Irajizad
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Johannes F. Fahrmann
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - James P. Long
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Jody Vykoukal
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Makoto Kobayashi
- Department of Basic Pathology, School of Medicine, Fukushima Medical University, Hikarigaoka, Fukushima 960-1247, Japan
| | - Michela Capello
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Chuan-Yih Yu
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Yining Cai
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Fu Chung Hsiao
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Nikul Patel
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Soyoung Park
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Qian Peng
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Jennifer B. Dennison
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Taketo Kato
- Department of Thoracic Surgery, Nagoya University, Nagoya 464-8601, Japan
| | - Mei Chee Tai
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Ayumu Taguchi
- Division of Molecular Diagnostics, Aichi Cancer Center, Nagoya 464-8601, Japan
- Division of Advanced Cancer Diagnostics, Nagoya University Graduate School of Medicine, Nagoya 464-8601, Japan
| | - Humam Kadara
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Ignacio I. Wistuba
- Department of Translational Molecular Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Hiroyuki Katayama
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
| | - Kim-Anh Do
- Department of Biostatistics, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
- Correspondence: (K.-A.D.); (S.M.H.); (E.J.O.); Tel.: +1-713-745-5242 (S.M.H.)
| | - Samir M. Hanash
- Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
- Correspondence: (K.-A.D.); (S.M.H.); (E.J.O.); Tel.: +1-713-745-5242 (S.M.H.)
| | - Edwin J. Ostrin
- Departments of General Internal Medicine, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX 77030, USA
- Correspondence: (K.-A.D.); (S.M.H.); (E.J.O.); Tel.: +1-713-745-5242 (S.M.H.)
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10
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Polyamines and Their Metabolism: From the Maintenance of Physiological Homeostasis to the Mediation of Disease. MEDICAL SCIENCES (BASEL, SWITZERLAND) 2022; 10:medsci10030038. [PMID: 35893120 PMCID: PMC9326668 DOI: 10.3390/medsci10030038] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/08/2022] [Accepted: 07/11/2022] [Indexed: 12/13/2022]
Abstract
The polyamines spermidine and spermine are positively charged aliphatic molecules. They are critical in the regulation of nucleic acid and protein structures, protein synthesis, protein and nucleic acid interactions, oxidative balance, and cell proliferation. Cellular polyamine levels are tightly controlled through their import, export, de novo synthesis, and catabolism. Enzymes and enzymatic cascades involved in polyamine metabolism have been well characterized. This knowledge has been used for the development of novel compounds for research and medical applications. Furthermore, studies have shown that disturbances in polyamine levels and their metabolic pathways, as a result of spontaneous mutations in patients, genetic engineering in mice or experimentally induced injuries in rodents, are associated with multiple maladaptive changes. The adverse effects of altered polyamine metabolism have also been demonstrated in in vitro models. These observations highlight the important role these molecules and their metabolism play in the maintenance of physiological normalcy and the mediation of injury. This review will attempt to cover the extensive and diverse knowledge of the biological role of polyamines and their metabolism in the maintenance of physiological homeostasis and the mediation of tissue injury.
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11
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Andreev DE, Loughran G, Fedorova AD, Mikhaylova MS, Shatsky IN, Baranov PV. Non-AUG translation initiation in mammals. Genome Biol 2022; 23:111. [PMID: 35534899 PMCID: PMC9082881 DOI: 10.1186/s13059-022-02674-2] [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: 08/14/2021] [Accepted: 04/14/2022] [Indexed: 12/12/2022] Open
Abstract
Recent proteogenomic studies revealed extensive translation outside of annotated protein coding regions, such as non-coding RNAs and untranslated regions of mRNAs. This non-canonical translation is largely due to start codon plurality within the same RNA. This plurality is often due to the failure of some scanning ribosomes to recognize potential start codons leading to initiation downstream—a process termed leaky scanning. Codons other than AUG (non-AUG) are particularly leaky due to their inefficiency. Here we discuss our current understanding of non-AUG initiation. We argue for a near-ubiquitous role of non-AUG initiation in shaping the dynamic composition of mammalian proteomes.
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12
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Andreev DE, Baranov PV, Milogorodskii A, Rachinskii D. A deterministic model for non-monotone relationship between translation of upstream and downstream open reading frames. MATHEMATICAL MEDICINE AND BIOLOGY : A JOURNAL OF THE IMA 2021; 38:490-515. [PMID: 34718568 DOI: 10.1093/imammb/dqab015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 08/12/2021] [Accepted: 10/06/2021] [Indexed: 01/01/2023]
Abstract
Totally asymmetric simple exclusion process (TASEP) modelling was shown to offer a parsimonious explanation for the experimentally confirmed ability of a single upstream open reading frames (uORFs) to upregulate downstream translation during the integrated stress response. As revealed by numerical simulations, the model predicts that reducing the density of scanning ribosomes upstream of certain uORFs increases the flow of ribosomes downstream. To gain a better insight into the mechanism which ensures the non-monotone relation between the upstream and downstream flows, in this work, we propose a phenomenological deterministic model approximating the TASEP model of the translation process. We establish the existence of a stationary solution featuring the decreasing density along the uORF for the deterministic model. Further, we find an explicit non-monotone relation between the upstream ribosome density and the downstream flow for the stationary solution in the limit of increasing uORF length and increasingly leaky initiation. The stationary distribution of the TASEP model, the stationary solution of the deterministic model and the explicit limit are compared numerically.
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Affiliation(s)
- D E Andreev
- Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow, 119991, Russian Federation, and Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
| | - P V Baranov
- University College Cork, College Road, Cork, T12 K8AF, Ireland, and Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry (RAS), 16/10 Miklukho-Maklay str., Moscow, 117997, Russian Federation
| | - A Milogorodskii
- Lomonosov Moscow State University, GSP-1, Leninskie Gory, Moscow, 119991, Russian Federation, and Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, RAS, Moscow, Russia
| | - D Rachinskii
- Department of Mathematical Sciences, The University of Texas at Dallas, 800 W. Campbell Rd, Richardson, TX 75080, USA
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13
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Translational and post-translational regulation of polyamine metabolic enzymes in plants. J Biotechnol 2021; 344:1-10. [PMID: 34915092 DOI: 10.1016/j.jbiotec.2021.12.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 09/19/2021] [Accepted: 12/03/2021] [Indexed: 10/19/2022]
Abstract
Polyamines are small organic and basic polycations that perform essential regulatory functions in all living organisms. Fluctuations in polyamine content have been observed to occur during growth, development and under stress conditions, implying that polyamines play pivotal roles in diverse cellular and physiological processes. To achieve polyamine homeostasis, the entire metabolic pathway is subjected to a fine-tuned regulation of its biosynthetic and catabolic genes and enzymes. In this review, we describe and discuss the most important mechanisms implicated in the translational and post-translational regulation of polyamine metabolic enzymes in plants. At the translational level, we emphasize the role of polyamines in the modulation of upstream open reading frame (uORF) activities that control the translation of polyamine biosynthetic and catabolic mRNAs. At the post-translational level, different aspects of the regulation of polyamine metabolic proteins are depicted, such as the proteolytic activation of enzyme precursors, the importance of dimerization in protein stability as well as in protein intracellular localization.
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14
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Vindu A, Shin BS, Choi K, Christenson ET, Ivanov IP, Cao C, Banerjee A, Dever TE. Translational autoregulation of the S. cerevisiae high-affinity polyamine transporter Hol1. Mol Cell 2021; 81:3904-3918.e6. [PMID: 34375581 PMCID: PMC8500938 DOI: 10.1016/j.molcel.2021.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/15/2021] [Accepted: 07/13/2021] [Indexed: 12/13/2022]
Abstract
Polyamines, small organic polycations, are essential for cell viability, and their physiological levels are homeostatically maintained by post-transcriptional regulation of key biosynthetic enzymes. In addition to de novo synthesis, cells can also take up polyamines; however, identifying cellular polyamine transporters has been challenging. Here we show that the S. cerevisiae HOL1 mRNA is under translational control by polyamines, and we reveal that the encoded membrane transporter Hol1 is a high-affinity polyamine transporter and is required for yeast growth under limiting polyamine conditions. Moreover, we show that polyamine inhibition of the translation factor eIF5A impairs translation termination at a Pro-Ser-stop motif in a conserved upstream open reading frame on the HOL1 mRNA to repress Hol1 synthesis under conditions of elevated polyamines. Our findings reveal that polyamine transport, like polyamine biosynthesis, is under translational autoregulation by polyamines in yeast, highlighting the extensive control cells impose on polyamine levels.
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Affiliation(s)
- Arya Vindu
- Section on Protein Biosynthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Byung-Sik Shin
- Section on Protein Biosynthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin Choi
- Section on Structural and Chemical Biology of Membrane Proteins, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Eric T Christenson
- Section on Structural and Chemical Biology of Membrane Proteins, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ivaylo P Ivanov
- Section on Protein Biosynthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chune Cao
- Section on Protein Biosynthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anirban Banerjee
- Section on Structural and Chemical Biology of Membrane Proteins, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Thomas E Dever
- Section on Protein Biosynthesis, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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15
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Han P, Shichino Y, Schneider-Poetsch T, Mito M, Hashimoto S, Udagawa T, Kohno K, Yoshida M, Mishima Y, Inada T, Iwasaki S. Genome-wide Survey of Ribosome Collision. Cell Rep 2021; 31:107610. [PMID: 32375038 DOI: 10.1016/j.celrep.2020.107610] [Citation(s) in RCA: 96] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2019] [Revised: 03/18/2020] [Accepted: 04/13/2020] [Indexed: 12/31/2022] Open
Abstract
Ribosome movement is not always smooth and is rather often impeded. For ribosome pauses, fundamental issues remain to be addressed, including where ribosomes pause on mRNAs, what kind of RNA/amino acid sequence causes this pause, and the physiological significance of this attenuation of protein synthesis. Here, we survey the positions of ribosome collisions caused by ribosome pauses in humans and zebrafish using modified ribosome profiling. Collided ribosomes, i.e., disomes, emerge at various sites: Pro-Pro/Gly/Asp motifs; Arg-X-Lys motifs; stop codons; and 3' untranslated regions. The electrostatic interaction between the charged nascent chain and the ribosome exit tunnel determines the eIF5A-mediated disome rescue at the Pro-Pro sites. In particular, XBP1u, a precursor of endoplasmic reticulum (ER)-stress-responsive transcription factor, shows striking queues of collided ribosomes and thus acts as a degradation substrate by ribosome-associated quality control. Our results provide insight into the causes and consequences of ribosome pause by dissecting collided ribosomes.
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Affiliation(s)
- Peixun Han
- 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
| | - Yuichi Shichino
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Tilman Schneider-Poetsch
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan
| | - Mari Mito
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
| | - Satoshi Hashimoto
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Tsuyoshi Udagawa
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Kenji Kohno
- Institute for Research Initiatives, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Minoru Yoshida
- Chemical Genomics Research Group, RIKEN Center for Sustainable Resource Science, Wako, Saitama 351-0198, Japan; Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan; Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Yuichiro Mishima
- Faculty of Life Sciences, Kyoto Sangyo University, Kita-ku, Kyoto 603-8555, Japan
| | - Toshifumi Inada
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, 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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16
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Nakanishi S, Cleveland JL. Polyamine Homeostasis in Development and Disease. MEDICAL SCIENCES (BASEL, SWITZERLAND) 2021; 9:medsci9020028. [PMID: 34068137 PMCID: PMC8162569 DOI: 10.3390/medsci9020028] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/02/2021] [Accepted: 05/06/2021] [Indexed: 12/12/2022]
Abstract
Polycationic polyamines are present in nearly all living organisms and are essential for mammalian cell growth and survival, and for development. These positively charged molecules are involved in a variety of essential biological processes, yet their underlying mechanisms of action are not fully understood. Several studies have shown both beneficial and detrimental effects of polyamines on human health. In cancer, polyamine metabolism is frequently dysregulated, and elevated polyamines have been shown to promote tumor growth and progression, suggesting that targeting polyamines is an attractive strategy for therapeutic intervention. In contrast, polyamines have also been shown to play critical roles in lifespan, cardiac health and in the development and function of the brain. Accordingly, a detailed understanding of mechanisms that control polyamine homeostasis in human health and disease is needed to develop safe and effective strategies for polyamine-targeted therapy.
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17
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Wang P, Jin S, Chen X, Wu L, Zheng Y, Yue C, Guo Y, Zhang X, Yang J, Ye N. Chromatin accessibility and translational landscapes of tea plants under chilling stress. HORTICULTURE RESEARCH 2021; 8:96. [PMID: 33931606 PMCID: PMC8087716 DOI: 10.1038/s41438-021-00529-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 05/03/2023]
Abstract
Plants have evolved regulatory mechanisms at multiple levels to regulate gene expression in order to improve their cold adaptability. However, limited information is available regarding the stress response at the chromatin and translational levels. Here, we characterize the chromatin accessibility, transcriptional, and translational landscapes of tea plants in vivo under chilling stress for the first time. Chilling stress significantly affected both the transcription and translation levels as well as the translation efficiency of tea plants. A total of 3010 genes that underwent rapid and independent translation under chilling stress were observed, and they were significantly enriched in the photosynthesis-antenna protein and phenylpropanoid biosynthesis pathways. A set of genes that were significantly responsive to cold at the transcription and translation levels, including four (+)-neomenthol dehydrogenases (MNDs) and two (E)-nerolidol synthases (NESs) arranged in tandem on the chromosomes, were also found. We detected potential upstream open reading frames (uORFs) on 3082 genes and found that tea plants may inhibit the overall expression of genes by enhancing the translation of uORFs under chilling stress. In addition, we identified distal transposase hypersensitive sites (THSs) and proximal THSs and constructed a transcriptional regulatory network for tea plants under chilling stress. We also identified 13 high-confidence transcription factors (TFs) that may play a crucial role in cold regulation. These results provide valuable information regarding the potential transcriptional regulatory network in plants and help to clarify how plants exhibit flexible responses to chilling stress.
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Affiliation(s)
- Pengjie Wang
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Shan Jin
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Xuejin Chen
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Liangyu Wu
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Yucheng Zheng
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Chuan Yue
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Yongchun Guo
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China
| | - Xingtan Zhang
- Shenzhen Branch, Guangdong Laboratory for Lingnan Modern Agriculture, Genome Analysis Laboratory of the Ministry of Agriculture, Agricultural Genomics Institute at Shenzhen, Chinese Academy of Agricultural Sciences, Shenzhen, 518120, China
| | - Jiangfan Yang
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China.
| | - Naixing Ye
- College of Horticulture, Fujian Agriculture and Forestry University/Key Laboratory of Tea Science in Universities of Fujian Province, Fuzhou, 350002, China.
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18
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Tsednee M, Tanaka M, Kasai K, Fujiwara T. Boron-dependent regulation of translation through AUGUAA sequence in yeast. Yeast 2020; 37:638-646. [PMID: 33289202 DOI: 10.1002/yea.3526] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 09/24/2020] [Accepted: 10/09/2020] [Indexed: 12/31/2022] Open
Abstract
Under high boron (B) conditions, nodulin 26-like intrinsic protein 5;1 (NIP5;1) mRNA, a boric acid channel, is destabilized to avoid excess B entry into roots of Arabidopsis thaliana. In this regulation, the minimum upstream open reading frame (uORF), AUGUAA, in its 5'-untranslated region (5'-UTR) is essential, and high B enhances ribosome stalling at AUGUAA and leads to suppression of translation and mRNA degradation. This B-dependent AUGUAA-mediated regulation occurs also in animal transient expression and reticulocyte lysate translation systems. Thus, uncovering the ubiquitousness of B-dependent unique regulation is important to reveal the evolution of translational regulation. In the present study, we examined the regulation in Saccharomyces cerevisiae. Reporter assay showed that in yeast, carrying ATGTAA in 5'-UTR of NIP5;1 upstream of the reporter gene, the relative reporter activities were reduced significantly under high B conditions compared with control, whereas deletion of ATGTAA abolished such responses. This suggests that AUGUAA mediates B-dependent regulation of translation in Saccharomyces cerevisiae. Moreover, the deletion of ATGTAA resulted in up to 10-fold increase in general reporter activities indicating the suppression effect of AUGUAA on translation of the main ORF. Interestingly, mRNA level of the reporter gene was not affected by B in both yeast cells with and without AUGUAA. This finding reveals that in yeast, unlike the case in plants, mRNA degradation is not associated with AUGUAA regulation. Together, results suggest that B-dependent AUGUAA-mediated translational regulation is common among eukaryotes.
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Affiliation(s)
- Munkhtsetseg Tsednee
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Mayuki Tanaka
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Koji Kasai
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Toru Fujiwara
- Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
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19
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Takahashi H, Miyaki S, Onouchi H, Motomura T, Idesako N, Takahashi A, Murase M, Fukuyoshi S, Endo T, Satou K, Naito S, Itoh M. Exhaustive identification of conserved upstream open reading frames with potential translational regulatory functions from animal genomes. Sci Rep 2020; 10:16289. [PMID: 33004976 PMCID: PMC7530721 DOI: 10.1038/s41598-020-73307-6] [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: 03/27/2020] [Accepted: 09/15/2020] [Indexed: 11/17/2022] Open
Abstract
Upstream open reading frames (uORFs) are present in the 5′-untranslated regions of many eukaryotic mRNAs, and some peptides encoded by these regions play important regulatory roles in controlling main ORF (mORF) translation. We previously developed a novel pipeline, ESUCA, to comprehensively identify plant uORFs encoding functional peptides, based on genome-wide identification of uORFs with conserved peptide sequences (CPuORFs). Here, we applied ESUCA to diverse animal genomes, because animal CPuORFs have been identified only by comparing uORF sequences between a limited number of species, and how many previously identified CPuORFs encode regulatory peptides is unclear. By using ESUCA, 1517 (1373 novel and 144 known) CPuORFs were extracted from four evolutionarily divergent animal genomes. We examined the effects of 17 human CPuORFs on mORF translation using transient expression assays. Through these analyses, we identified seven novel regulatory CPuORFs that repressed mORF translation in a sequence-dependent manner, including one conserved only among Eutheria. We discovered a much higher number of animal CPuORFs than previously identified. Since most human CPuORFs identified in this study are conserved across a wide range of Eutheria or a wider taxonomic range, many CPuORFs encoding regulatory peptides are expected to be found in the identified CPuORFs.
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Affiliation(s)
- Hiro Takahashi
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, 920-1192, Japan. .,Graduate School of Horticulture, Chiba University, Matsudo, 271-8510, Japan. .,Fundamental Innovative Oncology Core Center, National Cancer Center, Tokyo, 104-0045, Japan.
| | - Shido Miyaki
- Graduate School of Horticulture, Chiba University, Matsudo, 271-8510, Japan
| | - Hitoshi Onouchi
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan
| | - Taichiro Motomura
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Nobuo Idesako
- Graduate School of Horticulture, Chiba University, Matsudo, 271-8510, Japan
| | - Anna Takahashi
- Faculty of Information Technologies and Control, Belarusian State University of Informatics and Radio Electronics, 220013, Minsk, Belarus.,College of Bioscience and Biotechnology, Chubu University, Kasugai, 487-8501, Japan
| | - Masataka Murase
- Graduate School of Medical Sciences, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Shuichi Fukuyoshi
- Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Toshinori Endo
- Graduate School of Information Science and Technology, Hokkaido University, Sapporo, 060-0814, Japan
| | - Kenji Satou
- Faculty of Biological Science and Technology, Institute of Science and Engineering, Kanazawa University, Kanazawa, 920-1192, Japan
| | - Satoshi Naito
- Graduate School of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.,Graduate School of Life Science, Hokkaido University, Sapporo, 060-0810, Japan
| | - Motoyuki Itoh
- Graduate School of Pharmaceutical Science, Chiba University, Chiba, 260-8675, Japan.
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20
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Unusually efficient CUG initiation of an overlapping reading frame in POLG mRNA yields novel protein POLGARF. Proc Natl Acad Sci U S A 2020; 117:24936-24946. [PMID: 32958672 DOI: 10.1073/pnas.2001433117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
While near-cognate codons are frequently used for translation initiation in eukaryotes, their efficiencies are usually low (<10% compared to an AUG in optimal context). Here, we describe a rare case of highly efficient near-cognate initiation. A CUG triplet located in the 5' leader of POLG messenger RNA (mRNA) initiates almost as efficiently (∼60 to 70%) as an AUG in optimal context. This CUG directs translation of a conserved 260-triplet-long overlapping open reading frame (ORF), which we call POLGARF (POLG Alternative Reading Frame). Translation of a short upstream ORF 5' of this CUG governs the ratio between POLG (the catalytic subunit of mitochondrial DNA polymerase) and POLGARF synthesized from a single POLG mRNA. Functional investigation of POLGARF suggests a role in extracellular signaling. While unprocessed POLGARF localizes to the nucleoli together with its interacting partner C1QBP, serum stimulation results in rapid cleavage and secretion of a POLGARF C-terminal fragment. Phylogenetic analysis shows that POLGARF evolved ∼160 million y ago due to a mammalian-wide interspersed repeat (MIR) transposition into the 5' leader sequence of the mammalian POLG gene, which became fixed in placental mammals. This discovery of POLGARF unveils a previously undescribed mechanism of de novo protein-coding gene evolution.
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21
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Dever TE, Ivanov IP, Sachs MS. Conserved Upstream Open Reading Frame Nascent Peptides That Control Translation. Annu Rev Genet 2020; 54:237-264. [PMID: 32870728 DOI: 10.1146/annurev-genet-112618-043822] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cells utilize transcriptional and posttranscriptional mechanisms to alter gene expression in response to environmental cues. Gene-specific controls, including changing the translation of specific messenger RNAs (mRNAs), provide a rapid means to respond precisely to different conditions. Upstream open reading frames (uORFs) are known to control the translation of mRNAs. Recent studies in bacteria and eukaryotes have revealed the functions of evolutionarily conserved uORF-encoded peptides. Some of these uORF-encoded nascent peptides enable responses to specific metabolites to modulate the translation of their mRNAs by stalling ribosomes and through ribosome stalling may also modulate the level of their mRNAs. In this review, we highlight several examples of conserved uORF nascent peptides that stall ribosomes to regulate gene expression in response to specific metabolites in bacteria, fungi, mammals, and plants.
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Affiliation(s)
- Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Ivaylo P Ivanov
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA; ,
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, Texas 77843, USA;
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22
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Akirtava C, McManus CJ. Control of translation by eukaryotic mRNA transcript leaders-Insights from high-throughput assays and computational modeling. WILEY INTERDISCIPLINARY REVIEWS-RNA 2020; 12:e1623. [PMID: 32869519 DOI: 10.1002/wrna.1623] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/23/2020] [Accepted: 07/30/2020] [Indexed: 12/21/2022]
Abstract
Eukaryotic gene expression is tightly regulated during translation of mRNA to protein. Mis-regulation of translation can lead to aberrant proteins which accumulate in cancers and cause neurodegenerative diseases. Foundational studies on model genes established fundamental roles for mRNA 5' transcript leader (TL) sequences in controlling ribosome recruitment, scanning, and initiation. TL cis-regulatory elements and their corresponding trans-acting factors control cap-dependent initiation under unstressed conditions. Under stress, cap-dependent initiation is suppressed, and specific mRNA structures and sequences promote translation of stress-responsive transcripts to remodel the proteome. In this review, we summarize current knowledge of TL functions in translation initiation. We focus on insights from high-throughput analyses of ribosome occupancy, mRNA structure, RNA Binding Protein occupancy, and massively parallel reporter assays. These data-driven approaches, coupled with computational analyses and modeling, have paved the way for a comprehensive understanding of TL functions. Finally, we will discuss areas of future research on the roles of mRNA sequences and structures in translation. This article is categorized under: Translation > Translation Mechanisms RNA Evolution and Genomics > Computational Analyses of RNA RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems.
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Affiliation(s)
- Christina Akirtava
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Charles Joel McManus
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA.,Computational Biology Department, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
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23
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Bekebrede AF, Keijer J, Gerrits WJJ, de Boer VCJ. The Molecular and Physiological Effects of Protein-Derived Polyamines in the Intestine. Nutrients 2020; 12:E197. [PMID: 31940783 PMCID: PMC7020012 DOI: 10.3390/nu12010197] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/08/2020] [Accepted: 01/09/2020] [Indexed: 02/07/2023] Open
Abstract
Consumption of a high-protein diet increases protein entry into the colon. Colonic microbiota can ferment proteins, which results in the production of protein fermentation end-products, like polyamines. This review describes the effects of polyamines on biochemical, cellular and physiological processes, with a focus on the colon. Polyamines (mainly spermine, spermidine, putrescine and cadaverine) are involved in the regulation of protein translation and gene transcription. In this, the spermidine-derived hypusination modification of EIF5A plays an important role. In addition, polyamines regulate metabolic functions. Through hypusination of EIF5A, polyamines also regulate translation of mitochondrial proteins, thereby increasing their expression. They can also induce mitophagy through various pathways, which helps to remove damaged organelles and improves cell survival. In addition, polyamines increase mitochondrial substrate oxidation by increasing mitochondrial Ca2+-levels. Putrescine can even serve as an energy source for enterocytes in the small intestine. By regulating the formation of the mitochondrial permeability transition pore, polyamines help maintain mitochondrial membrane integrity. However, their catabolism may also reduce metabolic functions by depleting intracellular acetyl-CoA levels, or through production of toxic by-products. Lastly, polyamines support gut physiology, by supporting barrier function, inducing gut maturation and increasing longevity. Polyamines thus play many roles, and their impact is strongly tissue- and dose-dependent. However, whether diet-derived increases in colonic luminal polyamine levels also impact intestinal physiology has not been resolved yet.
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Affiliation(s)
- Anna F. Bekebrede
- Human and Animal Physiology, Wageningen University and Research, 6708 WD Wageningen, The Netherlands; (A.F.B.); (J.K.)
- Animal Nutrition Group, Wageningen University and Research, 6708 WD Wageningen, The Netherlands;
| | - Jaap Keijer
- Human and Animal Physiology, Wageningen University and Research, 6708 WD Wageningen, The Netherlands; (A.F.B.); (J.K.)
| | - Walter J. J. Gerrits
- Animal Nutrition Group, Wageningen University and Research, 6708 WD Wageningen, The Netherlands;
| | - Vincent C. J. de Boer
- Human and Animal Physiology, Wageningen University and Research, 6708 WD Wageningen, The Netherlands; (A.F.B.); (J.K.)
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24
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Lin Y, May GE, Kready H, Nazzaro L, Mao M, Spealman P, Creeger Y, McManus CJ. Impacts of uORF codon identity and position on translation regulation. Nucleic Acids Res 2019; 47:9358-9367. [PMID: 31392980 PMCID: PMC6755093 DOI: 10.1093/nar/gkz681] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/15/2019] [Accepted: 07/25/2019] [Indexed: 01/03/2023] Open
Abstract
Translation regulation plays an important role in eukaryotic gene expression. Upstream open reading frames (uORFs) are potent regulatory elements located in 5′ mRNA transcript leaders. Translation of uORFs usually inhibit the translation of downstream main open reading frames, but some enhance expression. While a minority of uORFs encode conserved functional peptides, the coding regions of most uORFs are not conserved. Thus, the importance of uORF coding sequences on their regulatory functions remains largely unknown. We investigated the impact of an uORF coding region on gene regulation by assaying the functions of thousands of variants in the yeast YAP1 uORF. Varying uORF codons resulted in a wide range of functions, including repressing and enhancing expression of the downstream ORF. The presence of rare codons resulted in the most inhibitory YAP1 uORF variants. Inhibitory functions of such uORFs were abrogated by overexpression of complementary tRNA. Finally, regression analysis of our results indicated that both codon identity and position impact uORF function. Our results support a model in which a uORF coding sequence impacts its regulatory functions by altering the speed of uORF translation.
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Affiliation(s)
- Yizhu Lin
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Department of Cell and Tissue Biology, University of California, San Francisco, CA 94143, USA
| | - Gemma E May
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Hunter Kready
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Lauren Nazzaro
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - Mao Mao
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Roche Sequencing Solutions, Santa Clara, CA 95050, USA
| | - Pieter Spealman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Center for Genomics and Systems Biology, New York University, New York, NY 10003, USA
| | - Yehuda Creeger
- Molecular Biosensor and Imaging Center, Carnegie Mellon University, Pittsburgh, PA 15213, USA
| | - C Joel McManus
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.,Computational Biology Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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25
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McGillivray P, Ault R, Pawashe M, Kitchen R, Balasubramanian S, Gerstein M. A comprehensive catalog of predicted functional upstream open reading frames in humans. Nucleic Acids Res 2019; 46:3326-3338. [PMID: 29562350 PMCID: PMC6283423 DOI: 10.1093/nar/gky188] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 03/14/2018] [Indexed: 01/09/2023] Open
Abstract
Upstream open reading frames (uORFs) latent in mRNA transcripts are thought to modify translation of coding sequences by altering ribosome activity. Not all uORFs are thought to be active in such a process. To estimate the impact of uORFs on the regulation of translation in humans, we first circumscribed the universe of all possible uORFs based on coding gene sequence motifs and identified 1.3 million unique uORFs. To determine which of these are likely to be biologically relevant, we built a simple Bayesian classifier using 89 attributes of uORFs labeled as active in ribosome profiling experiments. This allowed us to extrapolate to a comprehensive catalog of likely functional uORFs. We validated our predictions using in vivo protein levels and ribosome occupancy from 46 individuals. This is a substantially larger catalog of functional uORFs than has previously been reported. Our ranked list of likely active uORFs allows researchers to test their hypotheses regarding the role of uORFs in health and disease. We demonstrate several examples of biological interest through the application of our catalog to somatic mutations in cancer and disease-associated germline variants in humans.
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Affiliation(s)
- Patrick McGillivray
- Molecular Biophysics and Biochemistry Department, Yale University, New Haven, CT 06520, USA
| | - Russell Ault
- Molecular Biophysics and Biochemistry Department, Yale University, New Haven, CT 06520, USA
| | - Mayur Pawashe
- Molecular Biophysics and Biochemistry Department, Yale University, New Haven, CT 06520, USA
| | - Robert Kitchen
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Suganthi Balasubramanian
- Molecular Biophysics and Biochemistry Department, Yale University, New Haven, CT 06520, USA.,Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA
| | - Mark Gerstein
- Molecular Biophysics and Biochemistry Department, Yale University, New Haven, CT 06520, USA.,Program in Computational Biology and Bioinformatics, Yale University, New Haven, CT 06520, USA.,Department of Computer Science, Yale University, New Haven, CT 06520 USA
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26
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Diaz de Arce AJ, Noderer WL, Wang CL. Complete motif analysis of sequence requirements for translation initiation at non-AUG start codons. Nucleic Acids Res 2019; 46:985-994. [PMID: 29228265 PMCID: PMC5778536 DOI: 10.1093/nar/gkx1114] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2017] [Accepted: 12/06/2017] [Indexed: 01/23/2023] Open
Abstract
The initiation of mRNA translation from start codons other than AUG was previously believed to be rare and of relatively low impact. More recently, evidence has suggested that as much as half of all translation initiation utilizes non-AUG start codons, codons that deviate from AUG by a single base. Furthermore, non-AUG start codons have been shown to be involved in regulation of expression and disease etiology. Yet the ability to gauge expression based on the sequence of a translation initiation site (start codon and its flanking bases) has been limited. Here we have performed a comprehensive analysis of translation initiation sites that utilize non-AUG start codons. By combining genetic-reporter, cell-sorting, and high-throughput sequencing technologies, we have analyzed the expression associated with all possible variants of the -4 to +4 positions of non-AUG translation initiation site motifs. This complete motif analysis revealed that 1) with the right sequence context, certain non-AUG start codons can generate expression comparable to that of AUG start codons, 2) sequence context affects each non-AUG start codon differently, and 3) initiation at non-AUG start codons is highly sensitive to changes in the flanking sequences. Complete motif analysis has the potential to be a key tool for experimental and diagnostic genomics.
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Affiliation(s)
| | - William L Noderer
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
| | - Clifford L Wang
- Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
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27
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Function and Evolution of Upstream ORFs in Eukaryotes. Trends Biochem Sci 2019; 44:782-794. [PMID: 31003826 DOI: 10.1016/j.tibs.2019.03.002] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/08/2019] [Accepted: 03/19/2019] [Indexed: 12/18/2022]
Abstract
There is growing interest in the role of translational regulation in cellular homeostasis during organismal development. Translation initiation is the rate-limiting step in mRNA translation and is central to translational regulation. Upstream open reading frames (uORFs) are regulatory elements that are prevalent in eukaryotic mRNAs. uORFs modulate the translation initiation rate of downstream coding sequences (CDSs) by sequestering ribosomes. Over the past several years, genome-wide studies have revealed the widespread regulatory functions of uORFs in different species in different biological contexts. Here, we review the current understanding of uORF-mediated translational regulation from the perspective of functional and evolutionary genomics and address remaining gaps that deserve further study.
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28
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Abstract
The polyamines spermidine, spermine, and their precursor putrescine are organic polycations involved in various cellular processes and are absolutely essential for cellular proliferation. Because of their crucial function in the cell, their intracellular concentration must be maintained at optimal levels. To a large extent, this regulation is achieved through the activity of an autoregulatory loop that involves two proteins, antizyme (Az) and antizyme inhibitor (AzI), that regulate the first enzyme in polyamine biosynthesis, ornithine decarboxylase (ODC), and polyamine uptake activity in response to intracellular polyamine levels. In this Minireview, I will discuss what has been learned about the mechanism of Az expression and its physical interaction with both ODC and AzI in the regulation of polyamines.
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Affiliation(s)
- Chaim Kahana
- From the Department of Molecular Genetics, the Weizmann Institute of Science, Rehovot 76100, Israel
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29
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Abstract
Polyamines are organic polycations that bind to a variety of cellular molecules, including nucleic acids. Within cells, polyamines contribute to both the efficiency and fidelity of protein synthesis. In addition to directly acting on the translation apparatus to stimulate protein synthesis, the polyamine spermidine serves as a precursor for the essential post-translational modification of the eukaryotic translation factor 5A (eIF5A), which is required for synthesis of proteins containing problematic amino acid sequence motifs, including polyproline tracts, and for termination of translation. The impact of polyamines on translation is highlighted by autoregulation of the translation of mRNAs encoding key metabolic and regulatory proteins in the polyamine biosynthesis pathway, including S-adenosylmethionine decarboxylase (AdoMetDC), antizyme (OAZ), and antizyme inhibitor 1 (AZIN1). Here, we highlight the roles of polyamines in general translation and also in the translational regulation of polyamine biosynthesis.
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Affiliation(s)
- Thomas E Dever
- From the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
| | - Ivaylo P Ivanov
- From the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892
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30
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Ramos-Molina B, Lambertos A, Peñafiel R. Antizyme Inhibitors in Polyamine Metabolism and Beyond: Physiopathological Implications. ACTA ACUST UNITED AC 2018; 6:medsci6040089. [PMID: 30304856 PMCID: PMC6313458 DOI: 10.3390/medsci6040089] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Revised: 10/02/2018] [Accepted: 10/04/2018] [Indexed: 12/25/2022]
Abstract
The intracellular levels of polyamines, cationic molecules involved in a myriad of cellular functions ranging from cellular growth, differentiation and apoptosis, is precisely regulated by antizymes and antizyme inhibitors via the modulation of the polyamine biosynthetic and transport systems. Antizymes, which are mainly activated upon high polyamine levels, inhibit ornithine decarboxylase (ODC), the key enzyme of the polyamine biosynthetic route, and exert a negative control of polyamine intake. Antizyme inhibitors (AZINs), which are proteins highly homologous to ODC, selectively interact with antizymes, preventing their action on ODC and the polyamine transport system. In this review, we will update the recent advances on the structural, cellular and physiological functions of AZINs, with particular emphasis on the action of these proteins in the regulation of polyamine metabolism. In addition, we will describe emerging evidence that suggests that AZINs may also have polyamine-independent effects on cells. Finally, we will discuss how the dysregulation of AZIN activity has been implicated in certain human pathologies such as cancer, fibrosis or neurodegenerative diseases.
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Affiliation(s)
- Bruno Ramos-Molina
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Laboratory of Cellular and Molecular Endocrinology, Institute of Biomedical Research in Malaga (IBIMA), Virgen de la Victoria University Hospital, 29010 Málaga, Spain.
- CIBER Physiopathology of Obesity and Nutrition (CIBERobn), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain.
| | - Ana Lambertos
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain.
| | - Rafael Peñafiel
- Department of Biochemistry and Molecular Biology B and Immunology, Faculty of Medicine, University of Murcia, 30100 Murcia, Spain.
- Biomedical Research Institute of Murcia (IMIB), 30120 Murcia, Spain.
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31
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Sheshukova EV, Komarova TV, Ershova NM, Bronstein AM, Dorokhov YL. The Expression of Matryoshka Gene Encoding a Homologue of Kunitz Peptidase Inhibitor Is Regulated Both at the Level of Transcription and Translation. BIOCHEMISTRY. BIOKHIMIIA 2018; 83:1255-1262. [PMID: 30472962 DOI: 10.1134/s0006297918100103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 07/05/2018] [Indexed: 11/23/2022]
Abstract
The gene for Kunitz peptidase inhibitor-like protein (KPILP) contains nested alternative open reading frame (aORF) that controls expression of the maternal mRNA. The content of NbKPILP mRNA in intact leaves of Nicotiana benthamiana plant is low but increases significantly upon extended dark exposure or when foreign nucleic acid is overexpressed in the cells. The NbKPILP gene promoter along with the expressed nested aORF are likely to play an important role in maintaining the levels of NbKPILP mRNA. To elucidate the role of NbKPILP promoter, we isolated a fragment of N. benthamiana chromosomal DNA upstream of the NbKPILP transcription start, sequenced it, and created constructs in which reporter E. coli uidA gene coding for β-D-glucuronidase (GUS) was placed under control of the NbKPILP promoter. By assessing the efficacy of uidA mRNA synthesis directed by the NbKPILP promoter and 35S promoter of the cauliflower mosaic virus in a transient expression system, we showed that the levels of GUS accumulation were comparable for both promoters. Prolonged incubation of the agroinjected plants in the darkness stimulated accumulation of the uidA mRNA directed by the NbKPILP promoter. Our experiments indicate that along with regulation at the transcriptional level, expression of NbKPILP mRNA can be affected by expression of the nested aORF controlled by the polypurine block (PPB) located upstream of its start codon, since introduction of mutations in the PPB resulted in significant accumulation of the NbKPILP mRNA. Nucleotide replacement in the aORF start codon led to the drastic increase in the amounts of NbKPILP mRNA and its protein product.
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Affiliation(s)
- E V Sheshukova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
| | - T V Komarova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - N M Ershova
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A M Bronstein
- Sechenov First Moscow State Medical University, Moscow, 119991, Russia
| | - Y L Dorokhov
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia.
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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32
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Andreev DE, Arnold M, Kiniry SJ, Loughran G, Michel AM, Rachinskii D, Baranov PV. TASEP modelling provides a parsimonious explanation for the ability of a single uORF to derepress translation during the integrated stress response. eLife 2018; 7:32563. [PMID: 29932418 PMCID: PMC6033536 DOI: 10.7554/elife.32563] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 06/21/2018] [Indexed: 12/13/2022] Open
Abstract
Translation initiation is the rate-limiting step of protein synthesis that is downregulated during the Integrated Stress Response (ISR). Previously, we demonstrated that most human mRNAs that are resistant to this inhibition possess translated upstream open reading frames (uORFs), and that in some cases a single uORF is sufficient for the resistance. Here we developed a computational model of Initiation Complexes Interference with Elongating Ribosomes (ICIER) to gain insight into the mechanism. We explored the relationship between the flux of scanning ribosomes upstream and downstream of a single uORF depending on uORF features. Paradoxically, our analysis predicts that reducing ribosome flux upstream of certain uORFs increases initiation downstream. The model supports the derepression of downstream translation as a general mechanism of uORF-mediated stress resistance. It predicts that stress resistance can be achieved with long slowly decoded uORFs that do not favor translation reinitiation and that start with initiators of low leakiness.
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Affiliation(s)
- Dmitry E Andreev
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Maxim Arnold
- Department of Mathematical Sciences, The University of Texas at Dallas, Richardson, United States
| | - Stephen J Kiniry
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Audrey M Michel
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Dmitrii Rachinskii
- Department of Mathematical Sciences, The University of Texas at Dallas, Richardson, United States
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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33
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Ivanov IP, Shin BS, Loughran G, Tzani I, Young-Baird SK, Cao C, Atkins JF, Dever TE. Polyamine Control of Translation Elongation Regulates Start Site Selection on Antizyme Inhibitor mRNA via Ribosome Queuing. Mol Cell 2018; 70:254-264.e6. [PMID: 29677493 PMCID: PMC5916843 DOI: 10.1016/j.molcel.2018.03.015] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Revised: 02/06/2018] [Accepted: 03/14/2018] [Indexed: 12/31/2022]
Abstract
Translation initiation is typically restricted to AUG codons, and scanning eukaryotic ribosomes inefficiently recognize near-cognate codons. We show that queuing of scanning ribosomes behind a paused elongating ribosome promotes initiation at upstream weak start sites. Ribosomal profiling reveals polyamine-dependent pausing of elongating ribosomes on a conserved Pro-Pro-Trp (PPW) motif in an inhibitory non-AUG-initiated upstream conserved coding region (uCC) of the antizyme inhibitor 1 (AZIN1) mRNA, encoding a regulator of cellular polyamine synthesis. Mutation of the PPW motif impairs initiation at the uCC's upstream near-cognate AUU start site and derepresses AZIN1 synthesis, whereas substitution of alternate elongation pause sequences restores uCC translation. Impairing ribosome loading reduces uCC translation and paradoxically derepresses AZIN1 synthesis. Finally, we identify the translation factor eIF5A as a sensor and effector for polyamine control of uCC translation. We propose that stalling of elongating ribosomes triggers queuing of scanning ribosomes and promotes initiation by positioning a ribosome near the start codon.
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Affiliation(s)
- Ivaylo P Ivanov
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; School of Biochemistry and Cell Biology, University College Cork, Cork T12 YT57, Ireland.
| | - Byung-Sik Shin
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork T12 YT57, Ireland
| | - Ioanna Tzani
- School of Biochemistry and Cell Biology, University College Cork, Cork T12 YT57, Ireland
| | - Sara K Young-Baird
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Chune Cao
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork T12 YT57, Ireland
| | - Thomas E Dever
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
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34
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Spealman P, Naik AW, May GE, Kuersten S, Freeberg L, Murphy RF, McManus J. Conserved non-AUG uORFs revealed by a novel regression analysis of ribosome profiling data. Genome Res 2017; 28:214-222. [PMID: 29254944 PMCID: PMC5793785 DOI: 10.1101/gr.221507.117] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 12/11/2017] [Indexed: 12/14/2022]
Abstract
Upstream open reading frames (uORFs), located in transcript leaders (5' UTRs), are potent cis-acting regulators of translation and mRNA turnover. Recent genome-wide ribosome profiling studies suggest that thousands of uORFs initiate with non-AUG start codons. Although intriguing, these non-AUG uORF predictions have been made without statistical control or validation; thus, the importance of these elements remains to be demonstrated. To address this, we took a comparative genomics approach to study AUG and non-AUG uORFs. We mapped transcription leaders in multiple Saccharomyces yeast species and applied a novel machine learning algorithm (uORF-seqr) to ribosome profiling data to identify statistically significant uORFs. We found that AUG and non-AUG uORFs are both frequently found in Saccharomyces yeasts. Although most non-AUG uORFs are found in only one species, hundreds have either conserved sequence or position within Saccharomyces uORFs initiating with UUG are particularly common and are shared between species at rates similar to that of AUG uORFs. However, non-AUG uORFs are translated less efficiently than AUG-uORFs and are less subject to removal via alternative transcription initiation under normal growth conditions. These results suggest that a subset of non-AUG uORFs may play important roles in regulating gene expression.
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Affiliation(s)
- Pieter Spealman
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Armaghan W Naik
- Computational Biology Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Gemma E May
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | | | | | - Robert F Murphy
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.,Computational Biology Department, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
| | - Joel McManus
- Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA
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35
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Abstract
Peptides encoded by short open reading frames (sORFs) are usually defined as peptides ≤100 aa long. Usually sORFs were ignored by automatic genome annotation programs due to the high probability of false discovery. However, improved computational tools along with a high-throughput RIBO-seq approach identified a myriad of translated sORFs. Their importance becomes evident as we are gaining experimental validation of their diverse cellular functions. This Review examines various computational and experimental approaches of sORFs identification as well as provides the summary of our current knowledge of their functional roles in cells.
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Affiliation(s)
- Anastasia Chugunova
- Lomonosov Moscow State University , Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow 119992, Russia.,Skolkovo Institute of Science and Technology , Skolkovo, Moscow Region 143025, Russia
| | - Tsimafei Navalayeu
- Lomonosov Moscow State University , Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow 119992, Russia
| | - Olga Dontsova
- Lomonosov Moscow State University , Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow 119992, Russia.,Skolkovo Institute of Science and Technology , Skolkovo, Moscow Region 143025, Russia
| | - Petr Sergiev
- Lomonosov Moscow State University , Department of Chemistry and A.N. Belozersky Institute of Physico-Chemical Biology, Moscow 119992, Russia.,Skolkovo Institute of Science and Technology , Skolkovo, Moscow Region 143025, Russia
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36
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Translation Initiation from Conserved Non-AUG Codons Provides Additional Layers of Regulation and Coding Capacity. mBio 2017; 8:mBio.00844-17. [PMID: 28655822 PMCID: PMC5487733 DOI: 10.1128/mbio.00844-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Neurospora crassa cpc-1 and Saccharomyces cerevisiae GCN4 are homologs specifying transcription activators that drive the transcriptional response to amino acid limitation. The cpc-1 mRNA contains two upstream open reading frames (uORFs) in its >700-nucleotide (nt) 5′ leader, and its expression is controlled at the level of translation in response to amino acid starvation. We used N. crassa cell extracts and obtained data indicating that cpc-1 uORF1 and uORF2 are functionally analogous to GCN4 uORF1 and uORF4, respectively, in controlling translation. We also found that the 5′ region upstream of the main coding sequence of the cpc-1 mRNA extends for more than 700 nucleotides without any in-frame stop codon. For 100 cpc-1 homologs from Pezizomycotina and from selected Basidiomycota, 5′ conserved extensions of the CPC1 reading frame are also observed. Multiple non-AUG near-cognate codons (NCCs) in the CPC1 reading frame upstream of uORF2, some deeply conserved, could potentially initiate translation. At least four NCCs initiated translation in vitro. In vivo data were consistent with initiation at NCCs to produce N-terminally extended N. crassa CPC1 isoforms. The pivotal role played by CPC1, combined with its translational regulation by uORFs and NCC utilization, underscores the emerging significance of noncanonical initiation events in controlling gene expression. There is a deepening and widening appreciation of the diverse roles of translation in controlling gene expression. A central fungal transcription factor, the best-studied example of which is Saccharomyces cerevisiae GCN4, is crucial for the response to amino acid limitation. Two upstream open reading frames (uORFs) in the GCN4 mRNA are critical for controlling GCN4 synthesis. We observed that two uORFs in the corresponding Neurospora crassa cpc-1 mRNA appear functionally analogous to the GCN4 uORFs. We also discovered that, surprisingly, unlike GCN4, the CPC1 coding sequence extends far upstream from the presumed AUG start codon with no other in-frame AUG codons. Similar extensions were seen in homologs from many filamentous fungi. We observed that multiple non-AUG near-cognate codons (NCCs) in this extended reading frame, some conserved, initiated translation to produce longer forms of CPC1, underscoring the significance of noncanonical initiation in controlling gene expression.
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Fujii K, Shi Z, Zhulyn O, Denans N, Barna M. Pervasive translational regulation of the cell signalling circuitry underlies mammalian development. Nat Commun 2017; 8:14443. [PMID: 28195124 PMCID: PMC5316868 DOI: 10.1038/ncomms14443] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 12/29/2016] [Indexed: 12/11/2022] Open
Abstract
The degree and dynamics of translational control during mammalian development remain poorly understood. Here we monitored translation of the mammalian genome as cells become specified and organize into tissues in vivo. This identified unexpected and pervasive translational regulation of most of the core signalling circuitry including Shh, Wnt, Hippo, PI3K and MAPK pathways. We further identify and functionally characterize a complex landscape of upstream open reading frames (uORFs) across 5'-untranslated regions (UTRs) of key signalling components. Focusing on the Shh pathway, we demonstrate the importance of uORFs within the major SHH receptor, Ptch1, in control of cell signalling and neuronal differentiation. Finally, we show that the expression of hundreds of mRNAs underlying critical tissue-specific developmental processes is largely regulated at the translation but not transcript levels. Altogether, this work reveals a new layer of translational control to major signalling components and gene regulatory networks that diversifies gene expression spatially across developing tissues.
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Affiliation(s)
- Kotaro Fujii
- Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Zhen Shi
- Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Olena Zhulyn
- Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Nicolas Denans
- Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
| | - Maria Barna
- Department of Developmental Biology, Stanford University, Stanford, California 94305, USA.,Department of Genetics, Stanford University, Stanford, California 94305, USA
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38
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Andreev DE, O'Connor PBF, Loughran G, Dmitriev SE, Baranov PV, Shatsky IN. Insights into the mechanisms of eukaryotic translation gained with ribosome profiling. Nucleic Acids Res 2016; 45:513-526. [PMID: 27923997 PMCID: PMC5314775 DOI: 10.1093/nar/gkw1190] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 10/31/2016] [Accepted: 11/18/2016] [Indexed: 12/29/2022] Open
Abstract
The development of Ribosome Profiling (RiboSeq) has revolutionized functional genomics. RiboSeq is based on capturing and sequencing of the mRNA fragments enclosed within the translating ribosome and it thereby provides a ‘snapshot’ of ribosome positions at the transcriptome wide level. Although the method is predominantly used for analysis of differential gene expression and discovery of novel translated ORFs, the RiboSeq data can also be a rich source of information about molecular mechanisms of polypeptide synthesis and translational control. This review will focus on how recent findings made with RiboSeq have revealed important details of the molecular mechanisms of translation in eukaryotes. These include mRNA translation sensitivity to drugs affecting translation initiation and elongation, the roles of upstream ORFs in response to stress, the dynamics of elongation and termination as well as details of intrinsic ribosome behavior on the mRNA after translation termination. As the RiboSeq method is still at a relatively early stage we will also discuss the implications of RiboSeq artifacts on data interpretation.
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Affiliation(s)
- Dmitry E Andreev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | | | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Sergey E Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119234, Russia
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39
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Guerrero-González MDLL, Ortega-Amaro MA, Juárez-Montiel M, Jiménez-Bremont JF. Arabidopsis Polyamine oxidase-2 uORF is required for downstream translational regulation. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 108:381-390. [PMID: 27526386 DOI: 10.1016/j.plaphy.2016.08.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2016] [Revised: 08/04/2016] [Accepted: 08/04/2016] [Indexed: 05/10/2023]
Abstract
In eukaryotic mRNAs, small upstream open reading frames (uORFs) located in the 5'-untranslated region control the translation of the downstream main ORF. Polyamine oxidase (PAO) enzymes catalyze the oxidation of higher polyamines such as spermidine and spermine, and therefore contribute to the maintenance of intracellular polyamine content and to the regulation of physiological processes through their catabolic products. Recently, we reported that the Arabidopsis thaliana Polyamine Oxidase 2 (AtPAO2) is post-transcriptionally regulated by its 5'-UTR region through an uORF. In the present study, we analyzed whether the translation of the uORF is needed for the translational repression of the main ORF, and whether the inactivation of the uORF had an effect on the translational control mediated by polyamines. To this aim, we generated diverse single mutations in the uORF sequence; these mutant 5'-UTRs were fused to the GUS reporter gene, and tested in onion monolayer cells and A. thaliana transgenic seedlings. Removal of the start codon or introduction of a premature stop codon in the AtPAO2 uORF sequence abolished the negative regulation of the GUS expression exerted by the wild-type AtPAO2 uORF. An artificial uORF (32 amino acids in length) generated by the addition of a single nucleotide in AtPAO2 uORF proved to be less repressive than the wild-type uORF. Thus, our findings suggest that translation of the AtPAO2 uORF is necessary for the translational repression of the main ORF.
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Affiliation(s)
| | - María Azucena Ortega-Amaro
- Instituto Potosino de Investigación Científica y Tecnológica AC, División de Biología Molecular, San Luis Potosí, Mexico
| | - Margarita Juárez-Montiel
- Instituto Potosino de Investigación Científica y Tecnológica AC, División de Biología Molecular, San Luis Potosí, Mexico
| | - Juan Francisco Jiménez-Bremont
- Instituto Potosino de Investigación Científica y Tecnológica AC, División de Biología Molecular, San Luis Potosí, Mexico.
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40
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Atkins JF, Loughran G, Bhatt PR, Firth AE, Baranov PV. Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use. Nucleic Acids Res 2016; 44:7007-78. [PMID: 27436286 PMCID: PMC5009743 DOI: 10.1093/nar/gkw530] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression.
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Affiliation(s)
- John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland School of Microbiology, University College Cork, Cork, Ireland Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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41
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Abstract
Long non-coding RNAs (lncRNAs) are a diverse class of RNAs that engage in numerous biological processes across every branch of life. Although initially discovered as mRNA-like transcripts that do not encode proteins, recent studies have revealed features of lncRNAs that further distinguish them from mRNAs. In this Review, we describe special events in the lifetimes of lncRNAs - before, during and after transcription - and discuss how these events ultimately shape the unique characteristics and functional roles of lncRNAs.
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Affiliation(s)
- Jeffrey J Quinn
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA.,Department of Bioengineering, Stanford University School of Medicine and School of Engineering, Stanford, California 94305, USA
| | - Howard Y Chang
- Center for Personal Dynamic Regulomes, Stanford University School of Medicine, Stanford, California 94305, USA
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42
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Remaining Mysteries of Molecular Biology: The Role of Polyamines in the Cell. J Mol Biol 2015; 427:3389-406. [DOI: 10.1016/j.jmb.2015.06.020] [Citation(s) in RCA: 401] [Impact Index Per Article: 44.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2015] [Revised: 06/12/2015] [Accepted: 06/29/2015] [Indexed: 11/23/2022]
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43
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Rajput B, Murphy TD, Pruitt KD. RefSeq curation and annotation of antizyme and antizyme inhibitor genes in vertebrates. Nucleic Acids Res 2015; 43:7270-9. [PMID: 26170238 PMCID: PMC4551939 DOI: 10.1093/nar/gkv713] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 07/01/2015] [Indexed: 12/29/2022] Open
Abstract
Polyamines are ubiquitous cations that are involved in regulating fundamental cellular processes such as cell growth and proliferation; hence, their intracellular concentration is tightly regulated. Antizyme and antizyme inhibitor have a central role in maintaining cellular polyamine levels. Antizyme is unique in that it is expressed via a novel programmed ribosomal frameshifting mechanism. Conventional computational tools are unable to predict a programmed frameshift, resulting in misannotation of antizyme transcripts and proteins on transcript and genomic sequences. Correct annotation of a programmed frameshifting event requires manual evaluation. Our goal was to provide an accurately curated and annotated Reference Sequence (RefSeq) data set of antizyme transcript and protein records across a broad taxonomic scope that would serve as standards for accurate representation of these gene products. As antizyme and antizyme inhibitor proteins are functionally connected, we also curated antizyme inhibitor genes to more fully represent the elegant biology of polyamine regulation. Manual review of genes for three members of the antizyme family and two members of the antizyme inhibitor family in 91 vertebrate organisms resulted in a total of 461 curated RefSeq records.
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Affiliation(s)
- Bhanu Rajput
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Terence D Murphy
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Bethesda, MD 20894, USA
| | - Kim D Pruitt
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 8600 Rockville Pike, Bethesda, MD 20894, USA
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44
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Stegehake D, Kurosinski MA, Schürmann S, Daniel J, Lüersen K, Liebau E. Polyamine-independent Expression of Caenorhabditis elegans Antizyme. J Biol Chem 2015; 290:18090-18101. [PMID: 26032421 DOI: 10.1074/jbc.m115.644385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2015] [Indexed: 11/06/2022] Open
Abstract
Degradation of ornithine decarboxylase, the rate-limiting enzyme of polyamine biosynthesis, is promoted by the protein antizyme. Expression of antizyme is positively regulated by rising polyamine concentrations that induce a +1 translational frameshift required for production of the full-length protein. Antizyme itself is negatively regulated by the antizyme inhibitor. In our study, the regulation of Caenorhabditis elegans antizyme was investigated, and the antizyme inhibitor was identified. By applying a novel GFP-based method to monitor antizyme frameshifting in vivo, we show that the induction of translational frameshifting also occurs under stressful conditions. Interestingly, during starvation, the initiation of frameshifting was independent of polyamine concentrations. Because frameshifting was also prevalent in a polyamine auxotroph double mutant, a polyamine-independent regulation of antizyme frameshifting is suggested. Polyamine-independent induction of antizyme expression was found to be negatively regulated by the peptide transporter PEPT-1, as well as the target of rapamycin, but not by the daf-2 insulin signaling pathway. Stress-dependent expression of C. elegans antizyme occurred morely slowly than expression in response to increased polyamine levels, pointing to a more general reaction to unfavorable conditions and a diversion away from proliferation and reproduction toward conservation of energy. Interestingly, antizyme expression was found to drastically increase in aging individuals in a postreproductive manner. Although knockdown of antizyme did not affect the lifespan of C. elegans, knockdown of the antizyme inhibitor led to a significant reduction in lifespan. This is most likely caused by an increase in antizyme-mediated degradation of ornithine decarboxylase-1 and a resulting reduction in cellular polyamine levels.
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Affiliation(s)
- Dirk Stegehake
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany
| | - Marc-André Kurosinski
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany
| | - Sabine Schürmann
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany
| | - Jens Daniel
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany
| | - Kai Lüersen
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany
| | - Eva Liebau
- Department of Molecular Physiology, Institute for Animal Physiology, University of Muenster, 48143 Muenster, Germany.
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45
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Yordanova MM, Wu C, Andreev DE, Sachs MS, Atkins JF. A Nascent Peptide Signal Responsive to Endogenous Levels of Polyamines Acts to Stimulate Regulatory Frameshifting on Antizyme mRNA. J Biol Chem 2015; 290:17863-17878. [PMID: 25998126 PMCID: PMC4505036 DOI: 10.1074/jbc.m115.647065] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Indexed: 01/06/2023] Open
Abstract
The protein antizyme is a negative regulator of cellular polyamine concentrations from yeast to mammals. Synthesis of functional antizyme requires programmed +1 ribosomal frameshifting at the 3′ end of the first of two partially overlapping ORFs. The frameshift is the sensor and effector in an autoregulatory circuit. Except for Saccharomyces cerevisiae antizyme mRNA, the frameshift site alone only supports low levels of frameshifting. The high levels usually observed depend on the presence of cis-acting stimulatory elements located 5′ and 3′ of the frameshift site. Antizyme genes from different evolutionary branches have evolved different stimulatory elements. Prior and new multiple alignments of fungal antizyme mRNA sequences from the Agaricomycetes class of Basidiomycota show a distinct pattern of conservation 5′ of the frameshift site consistent with a function at the amino acid level. As shown here when tested in Schizosaccharomyces pombe and mammalian HEK293T cells, the 5′ part of this conserved sequence acts at the nascent peptide level to stimulate the frameshifting, without involving stalling detectable by toe-printing. However, the peptide is only part of the signal. The 3′ part of the stimulator functions largely independently and acts at least mostly at the nucleotide level. When polyamine levels were varied, the stimulatory effect was seen to be especially responsive in the endogenous polyamine concentration range, and this effect may be more general. A conserved RNA secondary structure 3′ of the frameshift site has weaker stimulatory and polyamine sensitizing effects on frameshifting.
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Affiliation(s)
- Martina M Yordanova
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Cheng Wu
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - Dmitry E Andreev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, Texas 77843-3258
| | - John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland; Department of Human Genetics, University of Utah, Salt Lake City, Utah 84112-5330.
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46
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Ma R, Jiang D, Kang B, Bai L, He H, Chen Z, Yi Z. Molecular cloning and mRNA expression analysis of antizyme inhibitor 1 in the ovarian follicles of the Sichuan white goose. Gene 2015; 568:55-60. [PMID: 25959024 DOI: 10.1016/j.gene.2015.05.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 04/03/2015] [Accepted: 05/06/2015] [Indexed: 11/18/2022]
Abstract
Antizyme inhibitor 1 (Azin1) plays critical roles in various cellular pathways, including ornithine decarboxylase regulation, polyamine anabolism and uptake and cell proliferation. However, the molecular characteristics of the AZIN1 gene and its expression profile in goose tissues and ovarian follicles have not been reported. In this study, the AZIN1 cDNA of the Sichuan white goose (Anser cygnoides) was cloned, and analyzed for its phylogenetic and physiochemical properties. The expression profile of AZIN1 mRNA in geese tissues and ovarian follicles were examined using quantitative real-time PCR. The results showed that the open reading frame of the AZIN1 cDNA is 1,353 bp in length, encoding a 450 amino acid protein with a molecular weight of 50 kDa. Out of all tissues examined, AZIN1 expression was highest in the adrenal gland and lowest in breast muscle. There was also a high expression of AZIN1 in the cerebellum and isthmus of oviduct. With follicular development, AZIN1 gene expression gradually increased, and its expression in F1 was significantly higher than in F5 (P<0.05). AZIN1 expression was also significantly higher in the POF1 than in the other follicles (P<0.05), and there was a low mRNA expression of AZIN1 in atretic follicles. The results of AZIN1 expression profiling in ovarian follicles suggest that AZIN1 may play an important role in the progression of follicular development, potentially through regulating polyamine levels.
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Affiliation(s)
- Rong Ma
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Dongmei Jiang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Bo Kang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China.
| | - Lin Bai
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Hui He
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Ziyu Chen
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
| | - Zhixin Yi
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan 611130, PR China
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47
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Silva TM, Cirenajwis H, Wallace HM, Oredsson S, Persson L. A role for antizyme inhibitor in cell proliferation. Amino Acids 2015; 47:1341-52. [PMID: 25813938 PMCID: PMC4458265 DOI: 10.1007/s00726-015-1957-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 03/06/2015] [Indexed: 12/20/2022]
Abstract
The polyamines are important for a variety of cellular functions, including cell growth. Their intracellular concentrations are controlled by a complex network of regulatory mechanisms, in which antizyme (Az) has a key role. Az reduces the cellular polyamine content by down-regulating both the enzyme catalysing polyamine biosynthesis, ornithine decarboxylase (ODC), and the uptake of polyamines. The activity of Az is repressed by the binding of a protein, named Az inhibitor (AzI), which is an enzymatically inactive homologue of ODC. Two forms of AzI have been described: AzI1, which is ubiquitous, and AzI2 which is expressed in brain and testis. In the present study, we have investigated the role of AzI1 in polyamine homeostasis and cell proliferation in breast cancer cells. The results obtained showed that the cellular content of AzI increased transiently after induction of cell proliferation by diluting cells in fresh medium. Inhibition of polyamine biosynthesis induced an even larger increase in the cellular AzI content, which remained significantly elevated during the 7-day experimental period. However, this increase was not a consequence of changes in cell cycle progression, as demonstrated by flow cytometry. Instead, the increase appeared to correlate with the cellular depletion of polyamines. Moreover, induced overexpression of AzI resulted in an increased cell proliferation with a concomitant increase in ODC activity and putrescine content. During mitosis, AzI1 was localised in a pattern that resembled that of the two centrosomes, confirming earlier observations. Taken together, the results indicate that AzI fulfils an essential regulatory function in polyamine homeostasis and cell proliferation.
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Affiliation(s)
- Tania M. Silva
- Department of Biology, Lund University, Lund, Sweden
- Present Address: Laboratory of Microbiology and Immunology of Infection, Institute for Molecular and Cell Biology, Porto University, Porto, Portugal
| | - Helena Cirenajwis
- Department of Biology, Lund University, Lund, Sweden
- Present Address: Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Heather M. Wallace
- Department of Biology, Lund University, Lund, Sweden
- Division of Applied Medicine, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen, UK
| | | | - Lo Persson
- Department of Experimental Medical Science, Lund University, Lund, Sweden
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48
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Laing WA, Martínez-Sánchez M, Wright MA, Bulley SM, Brewster D, Dare AP, Rassam M, Wang D, Storey R, Macknight RC, Hellens RP. An upstream open reading frame is essential for feedback regulation of ascorbate biosynthesis in Arabidopsis. THE PLANT CELL 2015; 27:772-86. [PMID: 25724639 PMCID: PMC4558653 DOI: 10.1105/tpc.114.133777] [Citation(s) in RCA: 137] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 01/18/2015] [Accepted: 02/11/2015] [Indexed: 05/18/2023]
Abstract
Ascorbate (vitamin C) is an essential antioxidant and enzyme cofactor in both plants and animals. Ascorbate concentration is tightly regulated in plants, partly to respond to stress. Here, we demonstrate that ascorbate concentrations are determined via the posttranscriptional repression of GDP-l-galactose phosphorylase (GGP), a major control enzyme in the ascorbate biosynthesis pathway. This regulation requires a cis-acting upstream open reading frame (uORF) that represses the translation of the downstream GGP open reading frame under high ascorbate concentration. Disruption of this uORF stops the ascorbate feedback regulation of translation and results in increased ascorbate concentrations in leaves. The uORF is predicted to initiate at a noncanonical codon (ACG rather than AUG) and encode a 60- to 65-residue peptide. Analysis of ribosome protection data from Arabidopsis thaliana showed colocation of high levels of ribosomes with both the uORF and the main coding sequence of GGP. Together, our data indicate that the noncanonical uORF is translated and encodes a peptide that functions in the ascorbate inhibition of translation. This posttranslational regulation of ascorbate is likely an ancient mechanism of control as the uORF is conserved in GGP genes from mosses to angiosperms.
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Affiliation(s)
- William A Laing
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | | | - Michele A Wright
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Sean M Bulley
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Di Brewster
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Andrew P Dare
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Maysoon Rassam
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Daisy Wang
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Roy Storey
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand
| | - Richard C Macknight
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand Biochemistry Department, University of Otago, Dunedin 9054, New Zealand
| | - Roger P Hellens
- The New Zealand Institute for Plant and Food Research, Auckland 1142, New Zealand Biochemistry Department, University of Otago, Dunedin 9054, New Zealand
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49
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Andreev DE, O'Connor PBF, Fahey C, Kenny EM, Terenin IM, Dmitriev SE, Cormican P, Morris DW, Shatsky IN, Baranov PV. Translation of 5' leaders is pervasive in genes resistant to eIF2 repression. eLife 2015; 4:e03971. [PMID: 25621764 PMCID: PMC4383229 DOI: 10.7554/elife.03971] [Citation(s) in RCA: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 01/22/2015] [Indexed: 12/18/2022] Open
Abstract
Eukaryotic cells rapidly reduce protein synthesis in response to various stress
conditions. This can be achieved by the phosphorylation-mediated inactivation of a
key translation initiation factor, eukaryotic initiation factor 2 (eIF2). However,
the persistent translation of certain mRNAs is required for deployment of an adequate
stress response. We carried out ribosome profiling of cultured human cells under
conditions of severe stress induced with sodium arsenite. Although this led to a
5.4-fold general translational repression, the protein coding open reading frames
(ORFs) of certain individual mRNAs exhibited resistance to the inhibition. Nearly all
resistant transcripts possess at least one efficiently translated upstream open
reading frame (uORF) that represses translation of the main coding ORF under normal
conditions. Site-specific mutagenesis of two identified stress resistant mRNAs
(PPP1R15B and IFRD1) demonstrated that a single uORF is sufficient for eIF2-mediated
translation control in both cases. Phylogenetic analysis suggests that at least two
regulatory uORFs (namely, in SLC35A4 and MIEF1) encode functional protein
products. DOI:http://dx.doi.org/10.7554/eLife.03971.001 Proteins carry out essential tasks for living cells and genes contain the
instructions to make proteins within their DNA. These instructions are copied to make
a molecule of mRNA, and a molecular machine known as a ribosome then reads and
translates the mRNA to build the protein. The first step in the translation process is called ‘initiation’ and
requires a protein called eIF2 to work together with the ribosome. This step involves
identifying an instruction called the start codon that marks the beginning of the
mRNA's coding sequence. The section of an mRNA molecule before the start codon
is not normally translated by the ribosome and is hence called the 5′
untranslated region. Building proteins requires energy and resources, and so it is carefully regulated. If
a cell is stressed, such as by being exposed to harmful chemicals, it makes fewer
proteins in order to conserve its resources. This down-regulation of protein
production is achieved in part by the cell chemically modifying its eIF2 proteins to
make them less able to initiate translation. However, stressed cells still continue
to make more of certain proteins that help them to combat stress. The mRNA molecules
for some of these proteins contain at least one other start codon in the 5′
untranslated region. The sequence that would be translated from such a start codon is
known as an upstream open reading frame (or uORF for short)—and this feature
is thought to help certain proteins to still be expressed despite low levels of
active eIF2. Andreev, O'Connor et al. have now analysed which mRNAs are
translated in human cells that have been treated with a chemical that induces stress
and makes the eIF2 protein less able to initiate translation. To do so, a technique
called ribosome profiling was used to identify all of the mRNA molecules bound to
ribosomes shortly after treatment with this chemical. Overall translation of most mRNAs in stressed cells was reduced to a quarter of the
normal level. However, Andreev, O'Connor et al. observed that the translation
of a few mRNAs continued almost as normal, or even increased, after the chemical
treatment. Notably, most of these mRNAs encoded regulatory proteins, which are not
required in large amounts. With one exception, all of these resistant mRNAs contained
uORFs. In unstressed cells, these uORFs were efficiently translated, while the same
mRNA's coding sequences were translated less efficiently. Andreev,
O'Connor et al. suggest that these two features could be used to identify
mRNAs that are still translated into working proteins when cells are stressed.
Further work is now needed to explore the mechanisms by which translation of these
uORFs allows mRNAs to resist the stress. DOI:http://dx.doi.org/10.7554/eLife.03971.002
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Affiliation(s)
- Dmitry E Andreev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | - Ciara Fahey
- Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
| | - Elaine M Kenny
- Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
| | - Ilya M Terenin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Sergey E Dmitriev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Paul Cormican
- Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
| | - Derek W Morris
- Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
| | - Ivan N Shatsky
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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50
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Ebina I, Takemoto-Tsutsumi M, Watanabe S, Koyama H, Endo Y, Kimata K, Igarashi T, Murakami K, Kudo R, Ohsumi A, Noh AL, Takahashi H, Naito S, Onouchi H. Identification of novel Arabidopsis thaliana upstream open reading frames that control expression of the main coding sequences in a peptide sequence-dependent manner. Nucleic Acids Res 2015; 43:1562-76. [PMID: 25618853 PMCID: PMC4330380 DOI: 10.1093/nar/gkv018] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Upstream open reading frames (uORFs) are often found in the 5'-leader regions of eukaryotic mRNAs and can negatively modulate the translational efficiency of the downstream main ORF. Although the effects of most uORFs are thought to be independent of their encoded peptide sequences, certain uORFs control translation of the main ORF in a peptide sequence-dependent manner. For genome-wide identification of such peptide sequence-dependent regulatory uORFs, exhaustive searches for uORFs with conserved amino acid sequences have been conducted using bioinformatic analyses. However, whether the conserved uORFs identified by these bioinformatic approaches encode regulatory peptides has not been experimentally determined. Here we analyzed 16 recently identified Arabidopsis thaliana conserved uORFs for the effects of their amino acid sequences on the expression of the main ORF using a transient expression assay. We identified five novel uORFs that repress main ORF expression in a peptide sequence-dependent manner. Mutational analysis revealed that, in four of them, the C-terminal region of the uORF-encoded peptide is critical for the repression of main ORF expression. Intriguingly, we also identified one exceptional sequence-dependent regulatory uORF, in which the stop codon position is not conserved and the C-terminal region is not important for the repression of main ORF expression.
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Affiliation(s)
- Isao Ebina
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | | | - Shun Watanabe
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Hiroaki Koyama
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Yayoi Endo
- Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Kaori Kimata
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Takuya Igarashi
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Karin Murakami
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Rin Kudo
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Arisa Ohsumi
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Abdul Latif Noh
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Hiro Takahashi
- Graduate School of Horticulture, Chiba University, Matsudo 271-8510, Japan
| | - Satoshi Naito
- Graduate School of Life Science, Hokkaido University, Sapporo 060-0810, Japan Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
| | - Hitoshi Onouchi
- Graduate School of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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