1
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Li L, Rybak MY, Lin J, Gagnon MG. The ribosome termination complex remodels release factor RF3 and ejects GDP. Nat Struct Mol Biol 2024:10.1038/s41594-024-01360-0. [PMID: 39030416 DOI: 10.1038/s41594-024-01360-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 06/26/2024] [Indexed: 07/21/2024]
Abstract
Translation termination involves release factors RF1, RF2 and the GTPase RF3 that recycles RF1 and RF2 from the ribosome. RF3 dissociates from the ribosome in the GDP-bound form and must then exchange GDP for GTP. The 70S ribosome termination complex (70S-TC) accelerates GDP exchange in RF3, suggesting that the 70S-TC can function as the guanine nucleotide exchange factor for RF3. Here, we use cryogenic-electron microscopy to elucidate the mechanism of GDP dissociation from RF3 catalyzed by the Escherichia coli 70S-TC. The non-rotated ribosome bound to RF1 remodels RF3 and induces a peptide flip in the phosphate-binding loop, efficiently ejecting GDP. Binding of GTP allows RF3 to dock at the GTPase center, promoting the dissociation of RF1 from the ribosome. The structures recapitulate the functional cycle of RF3 on the ribosome and uncover the mechanism by which the 70S-TC allosterically dismantles the phosphate-binding groove in RF3, a previously overlooked function of the ribosome.
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Affiliation(s)
- Li Li
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China
- Center for mRNA Translational Research, Fudan University, Shanghai, China
| | - Mariia Yu Rybak
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA
| | - Jinzhong Lin
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Zhongshan Hospital, Fudan University, Shanghai, China.
- Center for mRNA Translational Research, Fudan University, Shanghai, China.
| | - Matthieu G Gagnon
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA.
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
- Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, TX, USA.
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2
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Awad S, Valleriani A, Chiarugi D. A data-driven estimation of the ribosome drop-off rate in S. cerevisiae reveals a correlation with the genes length. NAR Genom Bioinform 2024; 6:lqae036. [PMID: 38638702 PMCID: PMC11025885 DOI: 10.1093/nargab/lqae036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 03/08/2024] [Accepted: 04/03/2024] [Indexed: 04/20/2024] Open
Abstract
Ribosomes are the molecular machinery that catalyse all the fundamental steps involved in the translation of mRNAs into proteins. Given the complexity of this process, the efficiency of protein synthesis depends on a large number of factors among which ribosome drop-off (i.e. the premature detachment of the ribosome from the mRNA template) plays an important role. However, an in vitro quantification of the extent to which ribosome drop-off occurs is not trivial due to difficulties in obtaining the needed experimental evidence. In this work we focus on the study of ribosome drop-off in Saccharomyces cerevisiae by using 'Ribofilio', a novel software tool that relies on a high sensitive strategy to estimate the ribosome drop-off rate from ribosome profiling data. Our results show that ribosome drop-off events occur at a significant rate also when S. cerevisiae is cultured in standard conditions. In this context, we also identified a correlation between the ribosome drop-off rate and the genes length: the longer the gene, the lower the drop-off rate.
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Affiliation(s)
- Sherine Awad
- Genomics and Bioinformatics Core Facility, Institute of Metabolic Science, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Angelo Valleriani
- Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14424 Potsdam, Germany
| | - Davide Chiarugi
- Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103 Leipzig - Germany
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3
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Chaiden C, Jaresitthikunchai J, Phaonakrop N, Roytrakul S, Kerdsin A, Nuanualsuwan S. Unlocking the Secrets of Streptococcus suis: A peptidomics comparison of virulent and non-virulent serotypes 2, 14, 18, and 19. PLoS One 2023; 18:e0287639. [PMID: 37384746 PMCID: PMC10310009 DOI: 10.1371/journal.pone.0287639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/09/2023] [Indexed: 07/01/2023] Open
Abstract
Streptococcus suis (S. suis) is an important bacterial pathogen, that causes serious infections in humans and pigs. Although numerous virulence factors have been proposed, their particular role in pathogenesis is still inconclusive. The current study explored putative peptides responsible for the virulence of S. suis serotype 2 (SS2). Thus, the peptidome of highly virulent SS2, less prevalent SS14, and rarely reported serotypes SS18 and SS19 were comparatively analyzed using a high-performance liquid chromatography-mass spectrometry method (LC-MS/MS). Six serotype-specific peptides, 2,3,4,5-tetrahydropyridine-2,6-dicarboxylate N-acetyltransferase (DapH), alanine racemase (Alr), CCA-adding enzyme (CCA), peptide chain release factor 3 (RF3), ATP synthase subunit delta (F0F1-ATPases) and aspartate carbamoyltransferase (ATCase), were expressed moderately to highly only in the SS2 peptidome with p-values of less than 0.05. Some of these proteins are responsible for bacterial cellular stability; especially, Alr was highly expressed in the SS2 peptidome and is associated with peptidoglycan biosynthesis and bacterial cell wall formation. This study indicated that these serotype-specific peptides, which were significantly expressed by virulent SS2, could serve as putative virulence factors to promote its competitiveness with other coexistences in a particular condition. Further in vivo studies of these peptides should be performed to confirm the virulence roles of these identified peptides.
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Affiliation(s)
- Chadaporn Chaiden
- Faculty of Veterinary Sciences, Department of Veterinary Public Health, Chulalongkorn University, Bangkok, Thailand
- Faculty of Veterinary Science, Department of Veterinary Public Health, Center of Excellence for Food and Water Risk Analysis (FAWRA), Chulalongkorn University, Bangkok, Thailand
| | - Janthima Jaresitthikunchai
- Functional Proteomics Technology Laboratory, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology for Development Agency, Pathum Thani, Thailand
| | - Narumon Phaonakrop
- Functional Proteomics Technology Laboratory, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology for Development Agency, Pathum Thani, Thailand
| | - Sittiruk Roytrakul
- Functional Proteomics Technology Laboratory, Functional Ingredients and Food Innovation Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology for Development Agency, Pathum Thani, Thailand
| | - Anusak Kerdsin
- Faculty of Public Health, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand
| | - Suphachai Nuanualsuwan
- Faculty of Veterinary Sciences, Department of Veterinary Public Health, Chulalongkorn University, Bangkok, Thailand
- Faculty of Veterinary Science, Department of Veterinary Public Health, Center of Excellence for Food and Water Risk Analysis (FAWRA), Chulalongkorn University, Bangkok, Thailand
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4
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Prabhakar A, Pavlov MY, Zhang J, Indrisiunaite G, Wang J, Lawson M, Ehrenberg M, Puglisi JD. Dynamics of release factor recycling during translation termination in bacteria. Nucleic Acids Res 2023; 51:5774-5790. [PMID: 37102635 PMCID: PMC10287982 DOI: 10.1093/nar/gkad286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Revised: 04/05/2023] [Accepted: 04/09/2023] [Indexed: 04/28/2023] Open
Abstract
In bacteria, release of newly synthesized proteins from ribosomes during translation termination is catalyzed by class-I release factors (RFs) RF1 or RF2, reading UAA and UAG or UAA and UGA codons, respectively. Class-I RFs are recycled from the post-termination ribosome by a class-II RF, the GTPase RF3, which accelerates ribosome intersubunit rotation and class-I RF dissociation. How conformational states of the ribosome are coupled to the binding and dissociation of the RFs remains unclear and the importance of ribosome-catalyzed guanine nucleotide exchange on RF3 for RF3 recycling in vivo has been disputed. Here, we profile these molecular events using a single-molecule fluorescence assay to clarify the timings of RF3 binding and ribosome intersubunit rotation that trigger class-I RF dissociation, GTP hydrolysis, and RF3 dissociation. These findings in conjunction with quantitative modeling of intracellular termination flows reveal rapid ribosome-dependent guanine nucleotide exchange to be crucial for RF3 action in vivo.
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Affiliation(s)
- Arjun Prabhakar
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
- Program in Biophysics, Stanford University, Stanford, CA 94305-5126, USA
| | - Michael Y Pavlov
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, Uppsala, Sweden
| | - Jingji Zhang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
| | - Gabriele Indrisiunaite
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, Uppsala, Sweden
| | - Jinfan Wang
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
| | - Michael R Lawson
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Biomedical Center, Box 596, Uppsala University, Uppsala, Sweden
| | - Joseph D Puglisi
- Department of Structural Biology, Stanford University School of Medicine, Stanford, CA 94305-5126, USA
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5
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Nagao A, Nakanishi Y, Yamaguchi Y, Mishina Y, Karoji M, Toya T, Fujita T, Iwasaki S, Miyauchi K, Sakaguchi Y, Suzuki T. Quality control of protein synthesis in the early elongation stage. Nat Commun 2023; 14:2704. [PMID: 37198183 PMCID: PMC10192219 DOI: 10.1038/s41467-023-38077-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 04/14/2023] [Indexed: 05/19/2023] Open
Abstract
In the early stage of bacterial translation, peptidyl-tRNAs frequently dissociate from the ribosome (pep-tRNA drop-off) and are recycled by peptidyl-tRNA hydrolase. Here, we establish a highly sensitive method for profiling of pep-tRNAs using mass spectrometry, and successfully detect a large number of nascent peptides from pep-tRNAs accumulated in Escherichia coli pthts strain. Based on molecular mass analysis, we found about 20% of the peptides bear single amino-acid substitutions of the N-terminal sequences of E. coli ORFs. Detailed analysis of individual pep-tRNAs and reporter assay revealed that most of the substitutions take place at the C-terminal drop-off site and that the miscoded pep-tRNAs rarely participate in the next round of elongation but dissociate from the ribosome. These findings suggest that pep-tRNA drop-off is an active mechanism by which the ribosome rejects miscoded pep-tRNAs in the early elongation, thereby contributing to quality control of protein synthesis after peptide bond formation.
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Affiliation(s)
- Asuteka Nagao
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Yui Nakanishi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yutaro Yamaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshifumi Mishina
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Minami Karoji
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Takafumi Toya
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Tomoya Fujita
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
| | - Shintaro Iwasaki
- RNA Systems Biochemistry Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama, 351-0198, Japan
- Department of Computational Biology and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa, Chiba, 277-8561, Japan
| | - Kenjyo Miyauchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yuriko Sakaguchi
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, Bunkyo-ku, Tokyo, 113-8656, Japan.
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6
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Zhang X, Han Y, Han X, Zhang S, Xiong L, Chen T. Peptide chain release factor DIG8 regulates plant growth by affecting ROS-mediated sugar transportation in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2023; 14:1172275. [PMID: 37063204 PMCID: PMC10102589 DOI: 10.3389/fpls.2023.1172275] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/14/2023] [Indexed: 06/19/2023]
Abstract
Chloroplasts have important roles in photosynthesis, stress sensing and retrograde signaling. However, the relationship between chloroplast peptide chain release factor and ROS-mediated plant growth is still unclear. In the present study, we obtained a loss-of-function mutant dig8 by EMS mutation. The dig8 mutant has few lateral roots and a pale green leaf phenotype. By map-based cloning, the DIG8 gene was located on AT3G62910, with a point mutation leading to amino acid substitution in functional release factor domain. Using yeast-two-hybrid and BiFC, we confirmed DIG8 protein was characterized locating in chloroplast by co-localization with plastid marker and interacting with ribosome-related proteins. Through observing by transmission electron microscopy, quantifying ROS content and measuring the transport efficiency of plasmodesmata in dig8 mutant, we found that abnormal thylakoid stack formation and chloroplast dysfunction in the dig8 mutant caused increased ROS activity leading to callose deposition and lower PD permeability. A local sugar supplement partially alleviated the growth retardation phenotype of the mutant. These findings shed light on chloroplast peptide chain release factor-affected plant growth by ROS stress.
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Affiliation(s)
- Xiangxiang Zhang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Yuliang Han
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Xiao Han
- College of Life Sciences, Fuzhou University, Fuzhou, China
| | - Siqi Zhang
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
| | - Liming Xiong
- Department of Biology, Hong Kong Baptist University, Kowloon Tang, Hong Kong, Hong Kong SAR, China
| | - Tao Chen
- Zhejiang Provincial Key Laboratory for Genetic Improvement and Quality Control of Medicinal Plants, College of Life and Environmental Science, Hangzhou Normal University, Hangzhou, China
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7
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Nguyen H, Hoffer E, Fagan C, Maehigashi T, Dunham C. Structural basis for reduced ribosomal A-site fidelity in response to P-site codon-anticodon mismatches. J Biol Chem 2023; 299:104608. [PMID: 36924943 PMCID: PMC10140155 DOI: 10.1016/j.jbc.2023.104608] [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: 02/01/2023] [Revised: 03/10/2023] [Accepted: 03/11/2023] [Indexed: 03/16/2023] Open
Abstract
Rapid and accurate translation is essential in all organisms to produce properly folded and functional proteins. mRNA codons that define the protein coding sequences are decoded by tRNAs on the ribosome in the aminoacyl (A) binding site. The mRNA codon and the tRNA anticodon interaction is extensively monitored by the ribosome to ensure accuracy in tRNA selection. While other polymerases that synthesize DNA and RNA can correct for misincorporations, the ribosome is unable to correct mistakes. Instead, when a misincorporation occurs, the mismatched tRNA-mRNA pair moves to the peptidyl (P) site and from this location, causes a reduction in the fidelity at the A site, triggering post-peptidyl transfer quality control. This reduced fidelity allows for additional incorrect tRNAs to be accepted and for release factor 2 (RF2) to recognize sense codons, leading to hydrolysis of the aberrant peptide. Here, we present crystal structures of the ribosome containing a tRNALys in the P site with a U•U mismatch with the mRNA codon. We find that when the mismatch occurs in the second position of the P-site codon-anticodon interaction, the first nucleotide of the A-site codon flips from the mRNA path to engage highly conserved 16S rRNA nucleotide A1493 in the decoding center. We propose that this mRNA nucleotide mispositioning leads to reduced fidelity at the A site. Further, this state may provide an opportunity for RF2 to initiate premature termination before erroneous nascent chains disrupt the cellular proteome.
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Affiliation(s)
- HaAn Nguyen
- Department of Chemistry, Emory University, Atlanta, GA USA; Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
| | - EricD Hoffer
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA; Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, GA USA
| | - CrystalE Fagan
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA; Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, GA USA
| | - Tatsuya Maehigashi
- Department of Chemistry, Emory University, Atlanta, GA USA; Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
| | - ChristineM Dunham
- Department of Chemistry, Emory University, Atlanta, GA USA; Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA.
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8
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Nguyen HA, Hoffer ED, Fagan CE, Maehigashi T, Dunham CM. Structural basis for reduced ribosomal A-site fidelity in response to P-site codon-anticodon mismatches. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.28.526049. [PMID: 36747737 PMCID: PMC9900946 DOI: 10.1101/2023.01.28.526049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Rapid and accurate translation is essential in all organisms to produce properly folded and functional proteins. mRNA codons that define the protein coding sequences are decoded by tRNAs on the ribosome in the aminoacyl (A) binding site. The mRNA codon and the tRNA anticodon interaction is extensively monitored by the ribosome to ensure accuracy in tRNA selection. While other polymerases that synthesize DNA and RNA can correct for misincorporations, the ribosome is unable to correct mistakes. Instead, when a misincorporation occurs, the mismatched tRNA-mRNA pair moves to the peptidyl (P) site and from this location, causes a reduction in the fidelity at the A site, triggering post-peptidyl transfer quality control. This reduced fidelity allows for additional incorrect tRNAs to be accepted and for release factor 2 (RF2) to recognize sense codons, leading to hydrolysis of the aberrant peptide. Here, we present crystal structures of the ribosome containing a tRNA Lys in the P site with a U•U mismatch with the mRNA codon. We find that when the mismatch occurs in the second position of the P-site codon-anticodon interaction, the first nucleotide of the A-site codon flips from the mRNA path to engage highly conserved 16S rRNA nucleotide A1493 in the decoding center. We propose that this mRNA nucleotide mispositioning leads to reduced fidelity at the A site. Further, this state may provide an opportunity for RF2 to initiate premature termination before erroneous nascent chains disrupt the cellular proteome.
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Affiliation(s)
- Ha An Nguyen
- Department of Chemistry, Emory University, Atlanta, GA USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
| | - Eric D. Hoffer
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, GA USA
| | - Crystal E. Fagan
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University, Atlanta, GA USA
| | - Tatsuya Maehigashi
- Department of Chemistry, Emory University, Atlanta, GA USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
| | - Christine M. Dunham
- Department of Chemistry, Emory University, Atlanta, GA USA
- Emory Antibiotic Resistance Center (ARC), Emory University, Atlanta, GA USA
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9
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Abstract
Translocation of transfer RNA (tRNA) and messenger RNA (mRNA) through the ribosome is catalyzed by the GTPase elongation factor G (EF-G) in bacteria. Although guanosine-5'-triphosphate (GTP) hydrolysis accelerates translocation and is required for dissociation of EF-G, its fundamental role remains unclear. Here, we used ensemble Förster resonance energy transfer (FRET) to monitor how inhibition of GTP hydrolysis impacts the structural dynamics of the ribosome. We used FRET pairs S12-S19 and S11-S13, which unambiguously report on rotation of the 30S head domain, and the S6-L9 pair, which measures intersubunit rotation. Our results show that, in addition to slowing reverse intersubunit rotation, as shown previously, blocking GTP hydrolysis slows forward head rotation. Surprisingly, blocking GTP hydrolysis completely abolishes reverse head rotation. We find that the S13-L33 FRET pair, which has been used in previous studies to monitor head rotation, appears to report almost exclusively on intersubunit rotation. Furthermore, we find that the signal from quenching of 3'-terminal pyrene-labeled mRNA, which is used extensively to follow mRNA translocation, correlates most closely with reverse intersubunit rotation. To account for our finding that blocking GTP hydrolysis abolishes a rotational event that occurs after the movements of mRNA and tRNAs are essentially complete, we propose that the primary role of GTP hydrolysis is to create an irreversible step in a mechanism that prevents release of EF-G until both the tRNAs and mRNA have moved by one full codon, ensuring productive translocation and maintenance of the translational reading frame.
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10
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Transcriptomic and Metabolomic Analysis of a Fusidic Acid-Selected fusA Mutant of Staphylococcus aureus. Antibiotics (Basel) 2022; 11:antibiotics11081051. [PMID: 36009920 PMCID: PMC9405211 DOI: 10.3390/antibiotics11081051] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 11/17/2022] Open
Abstract
Physiological experimentation, transcriptomics, and metabolomics were engaged to compare a fusidic acid-resistant Staphylococcus aureus mutant SH10001st-2 to its parent strain SH1000. SH10001st-2 harbored a mutation (H457Y) in the gene fusA which encodes the fusidic acid target, elongation factor G, as well as mutations in a putative phage gene of unknown function. SH10001st-2 grew slower than SH1000 at three temperatures and had reduced coagulase activity, two indicators of the fitness penalty reported for fusA-mediated fusidic acid- resistance in the absence of compensatory mutations. Despite the difference in growth rates, the levels of O2 consumption and CO2 production were comparable. Transcriptomic profiling revealed 326 genes were upregulated and 287 were downregulated in SH10001st-2 compared to SH1000. Cell envelope and transport and binding protein genes were the predominant functional categories of both upregulated and downregulated genes in SH10001st-2. Genes of virulence regulators, notably the agr and kdp systems, were highly upregulated as were genes encoding capsule production. Contrary to what is expected of mid-exponential phase cells, genes encoding secreted virulence factors were generally upregulated while those for adhesion-associated virulence factors were downregulated in SH10001st-2. Metabolomic analysis showed an overall increase in metabolite pools in SH10001st-2 compared to SH1000, mostly for amino acids and sugars. Slowed growth and metabolite accumulation may be byproducts of fusA mutation-mediated protein synthesis impairment, but the overall results indicate that SH10001st-2 is compensating for the H457Y fitness penalty by repurposing its virulence machinery, in conjunction with increasing metabolite uptake capacity, in order to increase nutrient acquisition.
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11
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Zhao L, Castanié-Cornet MP, Kumar S, Genevaux P, Hayer-Hartl M, Hartl FU. Bacterial RF3 senses chaperone function in co-translational folding. Mol Cell 2021; 81:2914-2928.e7. [PMID: 34107307 DOI: 10.1016/j.molcel.2021.05.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 04/05/2021] [Accepted: 05/13/2021] [Indexed: 10/21/2022]
Abstract
Molecular chaperones assist with protein folding by interacting with nascent polypeptide chains (NCs) during translation. Whether the ribosome can sense chaperone defects and, in response, abort translation of misfolding NCs has not yet been explored. Here we used quantitative proteomics to investigate the ribosome-associated chaperone network in E. coli and the consequences of its dysfunction. Trigger factor and the DnaK (Hsp70) system are the major NC-binding chaperones. HtpG (Hsp90), GroEL, and ClpB contribute increasingly when DnaK is deficient. Surprisingly, misfolding because of defects in co-translational chaperone function or amino acid analog incorporation results in recruitment of the non-canonical release factor RF3. RF3 recognizes aberrant NCs and then moves to the peptidyltransferase site to cooperate with RF2 in mediating chain termination, facilitating clearance by degradation. This function of RF3 reduces the accumulation of misfolded proteins and is critical for proteostasis maintenance and cell survival under conditions of limited chaperone availability.
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Affiliation(s)
- Liang Zhao
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Marie-Pierre Castanié-Cornet
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Sneha Kumar
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Pierre Genevaux
- Laboratoire de Microbiologie et Génétique Moléculaires, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, 118 route de Narbonne, 31062 Toulouse, France
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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12
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Yang J, Han YH, Im J, Seo SW. Synthetic protein quality control to enhance full-length translation in bacteria. Nat Chem Biol 2021; 17:421-427. [PMID: 33542534 DOI: 10.1038/s41589-021-00736-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Accepted: 01/08/2021] [Indexed: 01/30/2023]
Abstract
Coupled transcription and translation processes in bacteria cause indiscriminate translation of intact and truncated messenger RNAs, inevitably generating nonfunctional polypeptides. Here, we devised a synthetic protein quality control (ProQC) system that enables translation only when both ends of mRNAs are present and followed by circularization based on sequence-specific RNA-RNA hybridization. We demonstrate that the ProQC system dramatically improved the fraction of full-length proteins among all synthesized polypeptides by selectively translating intact mRNA and reducing abortive translation. As a result, full-length protein synthesis increased up to 2.5-fold without changing the transcription or translation efficiency. Furthermore, we applied the ProQC system for 3-hydroxypropionic acid, violacein and lycopene production by ensuring full-length expression of enzymes in biosynthetic pathways, resulting in 1.6- to 2.3-fold greater biochemical production. We believe that our ProQC system can be universally applied to improve not only the quality of recombinant protein production but also efficiencies of metabolic pathways.
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Affiliation(s)
- Jina Yang
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea.,Institute of Chemical Processes, Seoul National University, Seoul, Korea
| | - Yong Hee Han
- Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Korea
| | - Jongwon Im
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea
| | - Sang Woo Seo
- School of Chemical and Biological Engineering, Seoul National University, Seoul, Korea. .,Institute of Chemical Processes, Seoul National University, Seoul, Korea. .,Interdisciplinary Program in Bioengineering, Seoul National University, Seoul, Korea. .,Bio-MAX Institute, Seoul National University, Seoul, Korea. .,Institute of Engineering Research, Seoul National University, Seoul, Korea.
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13
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Translation error clusters induced by aminoglycoside antibiotics. Nat Commun 2021; 12:1830. [PMID: 33758186 PMCID: PMC7987974 DOI: 10.1038/s41467-021-21942-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 02/08/2021] [Indexed: 02/04/2023] Open
Abstract
Aminoglycoside antibiotics target the ribosome and induce mistranslation, yet which translation errors induce bacterial cell death is unclear. The analysis of cellular proteins by quantitative mass spectrometry shows that bactericidal aminoglycosides induce not only single translation errors, but also clusters of errors in full-length proteins in vivo with as many as four amino acid substitutions in a row. The downstream errors in a cluster are up to 10,000-fold more frequent than the first error and independent of the intracellular aminoglycoside concentration. The prevalence, length, and composition of error clusters depends not only on the misreading propensity of a given aminoglycoside, but also on its ability to inhibit ribosome translocation along the mRNA. Error clusters constitute a distinct class of misreading events in vivo that may provide the predominant source of proteotoxic stress at low aminoglycoside concentration, which is particularly important for the autocatalytic uptake of the drugs. Aminoglycoside antibiotics target the ribosome and induce misreading, yet which translation errors induce bacterial cell death is unclear. Here authors use quantitative mass spectrometry and show that bactericidal aminoglycosides induce clusters of errors in full-length proteins in vivo with as many as four amino acid substitutions in a row.
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14
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Müller C, Crowe-McAuliffe C, Wilson DN. Ribosome Rescue Pathways in Bacteria. Front Microbiol 2021; 12:652980. [PMID: 33815344 PMCID: PMC8012679 DOI: 10.3389/fmicb.2021.652980] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Ribosomes that become stalled on truncated or damaged mRNAs during protein synthesis must be rescued for the cell to survive. Bacteria have evolved a diverse array of rescue pathways to remove the stalled ribosomes from the aberrant mRNA and return them to the free pool of actively translating ribosomes. In addition, some of these pathways target the damaged mRNA and the incomplete nascent polypeptide chain for degradation. This review highlights the recent developments in our mechanistic understanding of bacterial ribosomal rescue systems, including drop-off, trans-translation mediated by transfer-messenger RNA and small protein B, ribosome rescue by the alternative rescue factors ArfA and ArfB, as well as Bacillus ribosome rescue factor A, an additional rescue system found in some Gram-positive bacteria, such as Bacillus subtilis. Finally, we discuss the recent findings of ribosome-associated quality control in particular bacterial lineages mediated by RqcH and RqcP. The importance of rescue pathways for bacterial survival suggests they may represent novel targets for the development of new antimicrobial agents against multi-drug resistant pathogenic bacteria.
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Affiliation(s)
| | | | - Daniel N. Wilson
- Institute for Biochemistry and Molecular Biology, University of Hamburg, Hamburg, Germany
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15
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Tollerson R, Ibba M. Translational regulation of environmental adaptation in bacteria. J Biol Chem 2020; 295:10434-10445. [PMID: 32518156 DOI: 10.1074/jbc.rev120.012742] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 06/08/2020] [Indexed: 01/26/2023] Open
Abstract
Bacteria must rapidly respond to both intracellular and environmental changes to survive. One critical mechanism to rapidly detect and adapt to changes in environmental conditions is control of gene expression at the level of protein synthesis. At each of the three major steps of translation-initiation, elongation, and termination-cells use stimuli to tune translation rate and cellular protein concentrations. For example, changes in nutrient concentrations in the cell can lead to translational responses involving mechanisms such as dynamic folding of riboswitches during translation initiation or the synthesis of alarmones, which drastically alter cell physiology. Moreover, the cell can fine-tune the levels of specific protein products using programmed ribosome pausing or inducing frameshifting. Recent studies have improved understanding and revealed greater complexity regarding long-standing paradigms describing key regulatory steps of translation such as start-site selection and the coupling of transcription and translation. In this review, we describe how bacteria regulate their gene expression at the three translational steps and discuss how translation is used to detect and respond to changes in the cellular environment. Finally, we appraise the costs and benefits of regulation at the translational level in bacteria.
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Affiliation(s)
- Rodney Tollerson
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
| | - Michael Ibba
- Department of Microbiology and Center for RNA Biology, Ohio State University, Columbus, Ohio, USA
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16
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Weber M, Burgos R, Yus E, Yang J, Lluch‐Senar M, Serrano L. Impact of C-terminal amino acid composition on protein expression in bacteria. Mol Syst Biol 2020; 16:e9208. [PMID: 32449593 PMCID: PMC7246954 DOI: 10.15252/msb.20199208] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 04/07/2020] [Accepted: 04/09/2020] [Indexed: 11/30/2022] Open
Abstract
The C-terminal sequence of a protein is involved in processes such as efficiency of translation termination and protein degradation. However, the general relationship between features of this C-terminal sequence and levels of protein expression remains unknown. Here, we identified C-terminal amino acid biases that are ubiquitous across the bacterial taxonomy (1,582 genomes). We showed that the frequency is higher for positively charged amino acids (lysine, arginine), while hydrophobic amino acids and threonine are lower. We then studied the impact of C-terminal composition on protein levels in a library of Mycoplasma pneumoniae mutants, covering all possible combinations of the two last codons. We found that charged and polar residues, in particular lysine, led to higher expression, while hydrophobic and aromatic residues led to lower expression, with a difference in protein levels up to fourfold. We further showed that modulation of protein degradation rate could be one of the main mechanisms driving these differences. Our results demonstrate that the identity of the last amino acids has a strong influence on protein expression levels.
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Affiliation(s)
- Marc Weber
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Raul Burgos
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Eva Yus
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Jae‐Seong Yang
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Maria Lluch‐Senar
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Luis Serrano
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
- ICREABarcelonaSpain
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17
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Thomas EN, Kim KQ, McHugh EP, Marcinkiewicz T, Zaher HS. Alkylative damage of mRNA leads to ribosome stalling and rescue by trans translation in bacteria. eLife 2020; 9:61984. [PMID: 32940602 PMCID: PMC7521929 DOI: 10.7554/elife.61984] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/16/2020] [Indexed: 02/06/2023] Open
Abstract
Similar to DNA replication, translation of the genetic code by the ribosome is hypothesized to be exceptionally sensitive to small chemical changes to its template mRNA. Here we show that the addition of common alkylating agents to growing cultures of Escherichia coli leads to the accumulation of several adducts within RNA, including N(1)-methyladenosine (m1A). As expected, the introduction of m1A to model mRNAs was found to reduce the rate of peptide bond formation by three orders of magnitude in a well-defined in vitro system. These observations suggest that alkylative stress is likely to stall translation in vivo and necessitates the activation of ribosome-rescue pathways. Indeed, the addition of alkylation agents was found to robustly activate the transfer-messenger RNA system, even when transcription was inhibited. Our findings suggest that bacteria carefully monitor the chemical integrity of their mRNA and they evolved rescue pathways to cope with its effect on translation.
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Affiliation(s)
- Erica N Thomas
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | - Kyusik Q Kim
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | - Emily P McHugh
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
| | | | - Hani S Zaher
- Department of Biology, Washington University in St. LouisSt. LouisUnited States
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18
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Fan Y, Thompson L, Lyu Z, Cameron TA, De Lay NR, Krachler AM, Ling J. Optimal translational fidelity is critical for Salmonella virulence and host interactions. Nucleic Acids Res 2019; 47:5356-5367. [PMID: 30941426 PMCID: PMC6547416 DOI: 10.1093/nar/gkz229] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/19/2019] [Accepted: 03/24/2019] [Indexed: 01/09/2023] Open
Abstract
Translational fidelity is required for accurate flow of genetic information, but is frequently altered by genetic changes and environmental stresses. To date, little is known about how translational fidelity affects the virulence and host interactions of bacterial pathogens. Here we show that surprisingly, either decreasing or increasing translational fidelity impairs the interactions of the enteric pathogen Salmonella Typhimurium with host cells and its fitness in zebrafish. Host interactions are mediated by Salmonella pathogenicity island 1 (SPI-1). Our RNA sequencing and quantitative RT-PCR results demonstrate that SPI-1 genes are among the most down-regulated when translational fidelity is either increased or decreased. Further, this down-regulation of SPI-1 genes depends on the master regulator HilD, and altering translational fidelity destabilizes HilD protein via enhanced degradation by Lon protease. Our work thus reveals that optimal translational fidelity is pivotal for adaptation of Salmonella to the host environment, and provides important mechanistic insights into this process.
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Affiliation(s)
- Yongqiang Fan
- College of Life and Health Sciences, Northeastern University, Shenyang 110819, People's Republic of China.,Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA.,Shenyang National Laboratory for Materials Science, Northeastern University, Shenyang 110819, People's Republic of China
| | - Laurel Thompson
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Zhihui Lyu
- Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
| | - Todd A Cameron
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Nicholas R De Lay
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Anne Marie Krachler
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Jiqiang Ling
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA.,Department of Cell Biology and Molecular Genetics, The University of Maryland, College Park, MD 20742, USA
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19
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Regulation of HIV-1 Gag-Pol Expression by Shiftless, an Inhibitor of Programmed -1 Ribosomal Frameshifting. Cell 2019; 176:625-635.e14. [PMID: 30682371 DOI: 10.1016/j.cell.2018.12.030] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 10/21/2018] [Accepted: 12/19/2018] [Indexed: 01/26/2023]
Abstract
Programmed -1 ribosomal frameshifting (-1PRF) is a widely used translation recoding mechanism. HIV-1 expresses Gag-Pol protein from the Gag-coding mRNA through -1PRF, and the ratio of Gag to Gag-Pol is strictly maintained for efficient viral replication. Here, we report that the interferon-stimulated gene product C19orf66 (herein named Shiftless) is a host factor that inhibits the -1PRF of HIV-1. Shiftless (SFL) also inhibited the -1PRF of a variety of mRNAs from both viruses and cellular genes. SFL interacted with the -1PRF signal of target mRNA and translating ribosomes and caused premature translation termination at the frameshifting site. Downregulation of translation release factor eRF3 or eRF1 reduced SFL-mediated premature translation termination. We propose that SFL binding to target mRNA and the translating ribosome interferes with the frameshifting process. These findings identify SFL as a broad-spectrum inhibitor of -1PRF and help to further elucidate the mechanisms of -1PRF.
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20
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Fan Y, Evans CR, Barber KW, Banerjee K, Weiss KJ, Margolin W, Igoshin OA, Rinehart J, Ling J. Heterogeneity of Stop Codon Readthrough in Single Bacterial Cells and Implications for Population Fitness. Mol Cell 2017; 67:826-836.e5. [PMID: 28781237 PMCID: PMC5591071 DOI: 10.1016/j.molcel.2017.07.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 05/22/2017] [Accepted: 07/07/2017] [Indexed: 12/30/2022]
Abstract
Gene expression noise (heterogeneity) leads to phenotypic diversity among isogenic individual cells. Our current understanding of gene expression noise is mostly limited to transcription, as separating translational noise from transcriptional noise has been challenging. It also remains unclear how translational heterogeneity originates. Using a transcription-normalized reporter system, we discovered that stop codon readthrough is heterogeneous among single cells, and individual cells with higher UGA readthrough grow faster from stationary phase. Our work also revealed that individual cells with lower protein synthesis levels exhibited higher UGA readthrough, which was confirmed with ribosome-targeting antibiotics (e.g., chloramphenicol). Further experiments and mathematical modeling suggest that varied competition between ternary complexes and release factors perturbs the UGA readthrough level. Our results indicate that fluctuations in the concentrations of translational components lead to UGA readthrough heterogeneity among single cells, which enhances phenotypic diversity of the genetically identical population and facilitates its adaptation to changing environments.
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MESH Headings
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- Codon, Terminator
- Escherichia coli/genetics
- Escherichia coli/growth & development
- Escherichia coli/metabolism
- Escherichia coli Proteins/biosynthesis
- Escherichia coli Proteins/genetics
- Gene Expression Regulation, Bacterial
- Genes, Reporter
- Genetic Fitness
- Genotype
- Kinetics
- Luminescent Proteins/biosynthesis
- Luminescent Proteins/genetics
- Microscopy, Fluorescence
- Models, Genetic
- One-Carbon Group Transferases
- Phenotype
- RNA, Bacterial/biosynthesis
- RNA, Bacterial/genetics
- RNA, Messenger/biosynthesis
- RNA, Messenger/genetics
- Transcription, Genetic
- Red Fluorescent Protein
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Affiliation(s)
- Yongqiang Fan
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Christopher R Evans
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA; Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Karl W Barber
- Department of Cellular & Molecular Physiology, Yale University, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Kinshuk Banerjee
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA
| | - Kalyn J Weiss
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA; Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - William Margolin
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA; Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Oleg A Igoshin
- Center for Theoretical Biological Physics, Rice University, Houston, TX 77005, USA; Department of Bioengineering, Rice University, Houston, TX 77005, USA
| | - Jesse Rinehart
- Department of Cellular & Molecular Physiology, Yale University, New Haven, CT 06520, USA; Systems Biology Institute, Yale University, West Haven, CT 06516, USA
| | - Jiqiang Ling
- Department of Microbiology and Molecular Genetics, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA; Graduate School of Biomedical Sciences, Houston, TX 77030, USA.
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21
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Zarai Y, Margaliot M, Tuller T. A deterministic mathematical model for bidirectional excluded flow with Langmuir kinetics. PLoS One 2017; 12:e0182178. [PMID: 28832591 PMCID: PMC5568237 DOI: 10.1371/journal.pone.0182178] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 07/13/2017] [Indexed: 11/30/2022] Open
Abstract
In many important cellular processes, including mRNA translation, gene transcription, phosphotransfer, and intracellular transport, biological "particles" move along some kind of "tracks". The motion of these particles can be modeled as a one-dimensional movement along an ordered sequence of sites. The biological particles (e.g., ribosomes or RNAPs) have volume and cannot surpass one another. In some cases, there is a preferred direction of movement along the track, but in general the movement may be bidirectional, and furthermore the particles may attach or detach from various regions along the tracks. We derive a new deterministic mathematical model for such transport phenomena that may be interpreted as a dynamic mean-field approximation of an important model from mechanical statistics called the asymmetric simple exclusion process (ASEP) with Langmuir kinetics. Using tools from the theory of monotone dynamical systems and contraction theory we show that the model admits a unique steady-state, and that every solution converges to this steady-state. Furthermore, we show that the model entrains (or phase locks) to periodic excitations in any of its forward, backward, attachment, or detachment rates. We demonstrate an application of this phenomenological transport model for analyzing ribosome drop off in mRNA translation.
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Affiliation(s)
- Yoram Zarai
- Dept. of Biomedical Engineering, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Michael Margaliot
- School of Electrical Engineering and the Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv 69978, Israel
| | - Tamir Tuller
- Dept. of Biomedical Engineering and the Sagol School of Neuroscience, Tel-Aviv University, Tel-Aviv 69978, Israel
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22
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Xu T, Wu Y, Lin Z, Bertram R, Götz F, Zhang Y, Qu D. Identification of Genes Controlled by the Essential YycFG Two-Component System Reveals a Role for Biofilm Modulation in Staphylococcus epidermidis. Front Microbiol 2017; 8:724. [PMID: 28491057 PMCID: PMC5405149 DOI: 10.3389/fmicb.2017.00724] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/07/2017] [Indexed: 01/11/2023] Open
Abstract
Biofilms play a crucial role in the pathogenicity of Staphylococcus epidermidis, while little is known about whether the essential YycFG two-component signal transduction system (TCS) is involved in biofilm formation. We used antisense RNA (asRNA) to silence the yycFG TCS in order to study its regulatory functions in S. epidermidis. Strain 1457 expressing asRNAyycF exhibited a significant delay (~4–5 h) in entry to log phase, which was partially complemented by overexpressing ssaA. The expression of asRNAyycF and asRNAyycG resulted in a 68 and 50% decrease in biofilm formation at 6 h, respectively, while they had no significant inhibitory effect on 12 h biofilm formation. The expression of asRNAyycF led to a ~5-fold increase in polysaccharide intercellular adhesion (PIA) production, but it did not affect the expression of accumulation-associated protein (Aap) or the release of extracellular DNA. Consistently, quantitative real-time PCR showed that silencing yycF resulted in an increased transcription of biofilm-related genes, including icaA, arlR, sarA, sarX, and sbp. An in silico search of the YycF regulon for the conserved YycF recognition pattern and a modified motif in S. epidermidis, along with additional gel shift and DNase I footprinting assays, showed that arlR, sarA, sarX, and icaA are directly regulated by YycF. Our data suggests that YycFG modulates S. epidermidis biofilm formation in an ica-dependent manner.
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Affiliation(s)
- Tao Xu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan UniversityShanghai, China.,Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China
| | - Yang Wu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan UniversityShanghai, China
| | - Zhiwei Lin
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan UniversityShanghai, China
| | - Ralph Bertram
- Klinikum Nürnberg Medical School GmbH, Research Department, Paracelsus Medical UniversityNuremberg, Germany.,Department of Microbial Genetics, Faculty of Science, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, University of TübingenTübingen, Germany
| | - Friedrich Götz
- Department of Microbial Genetics, Faculty of Science, Interfaculty Institute of Microbiology and Infection Medicine Tübingen, University of TübingenTübingen, Germany
| | - Ying Zhang
- Key Laboratory of Medical Molecular Virology, Huashan Hospital, Shanghai Medical College of Fudan UniversityShanghai, China.,Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins UniversityBaltimore, MD, USA
| | - Di Qu
- Key Laboratory of Medical Molecular Virology of Ministries of Education and Health, Department of Medical Microbiology and Parasitology, Institute of Medical Microbiology and Institutes of Biomedical Sciences, Fudan UniversityShanghai, China
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23
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Baggett NE, Zhang Y, Gross CA. Global analysis of translation termination in E. coli. PLoS Genet 2017; 13:e1006676. [PMID: 28301469 PMCID: PMC5373646 DOI: 10.1371/journal.pgen.1006676] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 03/30/2017] [Accepted: 03/08/2017] [Indexed: 01/01/2023] Open
Abstract
Terminating protein translation accurately and efficiently is critical for both protein fidelity and ribosome recycling for continued translation. The three bacterial release factors (RFs) play key roles: RF1 and 2 recognize stop codons and terminate translation; and RF3 promotes disassociation of bound release factors. Probing release factors mutations with reporter constructs containing programmed frameshifting sequences or premature stop codons had revealed a propensity for readthrough or frameshifting at these specific sites, but their effects on translation genome-wide have not been examined. We performed ribosome profiling on a set of isogenic strains with well-characterized release factor mutations to determine how they alter translation globally. Consistent with their known defects, strains with increasingly severe release factor defects exhibit increasingly severe accumulation of ribosomes over stop codons, indicative of an increased duration of the termination/release phase of translation. Release factor mutant strains also exhibit increased occupancy in the region following the stop codon at a significant number of genes. Our global analysis revealed that, as expected, translation termination is generally efficient and accurate, but that at a significant number of genes (≥ 50) the ribosome signature after the stop codon is suggestive of translation past the stop codon. Even native E. coli K-12 exhibits the ribosome signature suggestive of protein extension, especially at UGA codons, which rely exclusively on the reduced function RF2 variant of the K-12 strain for termination. Deletion of RF3 increases the severity of the defect. We unambiguously demonstrate readthrough and frameshifting protein extensions and their further accumulation in mutant strains for a few select cases. In addition to enhancing recoding, ribosome accumulation over stop codons disrupts attenuation control of biosynthetic operons, and may alter expression of some overlapping genes. Together, these functional alterations may either augment the protein repertoire or produce deleterious proteins. Proteins are the cellular workhorses, performing essentially all of the functions required for cell and organismal survival. But, it takes a great deal of energy to make proteins, making it critical that proteins are made accurately and in the proper time frame. After a ribosome synthesizes a protein, release factors catalyze the accurate and timely release of the finished protein from the ribosome, a process called termination. Ribosomes are then recycled and start the next protein. We utilized ribosome profiling, a method that allows us to follow the position of every ribosome that is making a protein, to globally investigate and strengthen insights on termination fidelity for cells with and without mutant release factors. We find that as we decrease release factor function, the time to terminate/release a protein increases across the genome. We observe that the accuracy of terminating a protein at the correct place decreases on a global scale. Using this metric we identify genes with inherently low termination efficiency and confirm two novel events resulting in extended protein products. In addition we find that beyond disrupting accurate protein synthesis, release factor mutations can alter expression of genes involved in the production of key amino acids.
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Affiliation(s)
- Natalie E. Baggett
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Yan Zhang
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
| | - Carol A. Gross
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, California, United States of America
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, California, United States of America
- California Institute of Quantitative Biology, University of California, San Francisco, San Francisco, California, United States of America
- * E-mail:
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24
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Shi X, Joseph S. Mechanism of Translation Termination: RF1 Dissociation Follows Dissociation of RF3 from the Ribosome. Biochemistry 2016; 55:6344-6354. [PMID: 27779391 DOI: 10.1021/acs.biochem.6b00921] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Release factors 1 and 2 (RF1 and RF2, respectively) bind to ribosomes that have a stop codon in the A site and catalyze the release of the newly synthesized protein. Following peptide release, the dissociation of RF1 and RF2 from the ribosome is accelerated by release factor 3 (RF3). The mechanism for RF3-promoted dissociation of RF1 and RF2 is unclear. It was previously proposed that RF3 hydrolyzes GTP and dissociates from the ribosome after RF1 dissociation. Here we monitored directly the dissociation kinetics of RF1 and RF3 using Förster resonance energy transfer-based assays. In contrast to the previous model, our data show that RF3 hydrolyzes GTP and dissociates from the ribosome before RF1 dissociation. We propose that RF3 stabilizes the ratcheted state of the ribosome, which consequently accelerates the dissociation of RF1 and RF2.
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Affiliation(s)
- Xinying Shi
- Department of Chemistry and Biochemistry, University of California, San Diego , 9500 Gilman Drive, La Jolla, California 92093-0314, United States
| | - Simpson Joseph
- Department of Chemistry and Biochemistry, University of California, San Diego , 9500 Gilman Drive, La Jolla, California 92093-0314, United States
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25
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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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26
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Protein Elongation, Co-translational Folding and Targeting. J Mol Biol 2016; 428:2165-85. [DOI: 10.1016/j.jmb.2016.03.022] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 03/21/2016] [Accepted: 03/22/2016] [Indexed: 11/18/2022]
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27
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Sin C, Chiarugi D, Valleriani A. Quantitative assessment of ribosome drop-off in E. coli. Nucleic Acids Res 2016; 44:2528-37. [PMID: 26935582 PMCID: PMC4824120 DOI: 10.1093/nar/gkw137] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/24/2016] [Indexed: 11/14/2022] Open
Abstract
Premature ribosome drop-off is one of the major errors in translation of mRNA by ribosomes. However, repeated analyses of Ribo-seq data failed to quantify its strength inE. coli Relying on a novel highly sensitive data analysis method we show that a significant rate of ribosome drop-off is measurable and can be quantified also when cells are cultured under non-stressing conditions. Moreover, we find that the drop-off rate is highly variable, depending on multiple factors. In particular, under environmental stress such as amino acid starvation or ethanol intoxication, the drop-off rate markedly increases.
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Affiliation(s)
- Celine Sin
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476 Potsdam, Germany
| | - Davide Chiarugi
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476 Potsdam, Germany
| | - Angelo Valleriani
- Department of Theory and Bio-Systems, Max Planck Institute of Colloids and Interfaces, Science Park Golm, 14476 Potsdam, Germany
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28
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Naganathan A, Wood MP, Moore SD. The large ribosomal subunit protein L9 enables the growth of EF-P deficient cells and enhances small subunit maturation. PLoS One 2015; 10:e0120060. [PMID: 25879934 PMCID: PMC4399890 DOI: 10.1371/journal.pone.0120060] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2014] [Accepted: 02/03/2015] [Indexed: 01/08/2023] Open
Abstract
The loss of the large ribosomal protein L9 causes a reduction in translation fidelity by an unknown mechanism. To identify pathways affected by L9, we identified mutants of E. coli that require L9 for fitness. In a prior study, we characterized L9-dependent mutations in the essential GTPase Der (EngA). Here, we describe a second class of L9-dependent mutations that either compromise or inactivate elongation factor P (EF-P, eIF5A in eukaryotes). Without L9, Δefp cells are practically inviable. Cell fractionation studies revealed that, in both the Der and EF-P mutant cases, L9's activity reduces immature 16S rRNA in 30S particles and partially restores the abundance of monosomes. Inspired by these findings, we discovered that L9 also enhances 16S maturation in wild-type cells. Surprisingly, although the amount of immature 16S in 30S particles was found to be elevated in ΔrplI cells, the amount in polysomes was low and inversely correlated with the immature 16S abundance. These findings provide an explanation for the observed fitness increases afforded by L9 in these mutants and reveal particular physiological conditions in which L9 becomes critical. Additionally, L9 may affect the partitioning of small subunits containing immature 16S rRNA.
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Affiliation(s)
- Anusha Naganathan
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, FL, 32816, United States of America
| | - Matthew P. Wood
- Seattle Biomed, 307 Westlake Ave N, Suite 500, Seattle, WA, 98109, United States of America
- Department of Global Health, University of Washington, 1510 N.E. San Juan Road, Seattle, WA, 98195, United States of America
| | - Sean D. Moore
- The Burnett School of Biomedical Sciences, College of Medicine, The University of Central Florida, Orlando, FL, 32816, United States of America
- * E-mail:
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29
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An integrated approach reveals regulatory controls on bacterial translation elongation. Cell 2015; 159:1200-1211. [PMID: 25416955 DOI: 10.1016/j.cell.2014.10.043] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 08/18/2014] [Accepted: 10/21/2014] [Indexed: 12/16/2022]
Abstract
Ribosomes elongate at a nonuniform rate during translation. Theoretical models and experiments disagree on the in vivo determinants of elongation rate and the mechanism by which elongation rate affects protein levels. To resolve this conflict, we measured transcriptome-wide ribosome occupancy under multiple conditions and used it to formulate a whole-cell model of translation in E. coli. Our model predicts that elongation rates at most codons during nutrient-rich growth are not limited by the intracellular concentrations of aminoacyl-tRNAs. However, elongation pausing during starvation for single amino acids is highly sensitive to the kinetics of tRNA aminoacylation. We further show that translation abortion upon pausing accounts for the observed ribosome occupancy along mRNAs during starvation. Abortion reduces global protein synthesis, but it enhances the translation of a subset of mRNAs. These results suggest a regulatory role for aminoacylation and abortion during stress, and our study provides an experimentally constrained framework for modeling translation.
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30
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Atkinson GC. The evolutionary and functional diversity of classical and lesser-known cytoplasmic and organellar translational GTPases across the tree of life. BMC Genomics 2015; 16:78. [PMID: 25756599 PMCID: PMC4342817 DOI: 10.1186/s12864-015-1289-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/27/2015] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND The ribosome translates mRNA to protein with the aid of a number of accessory protein factors. Translational GTPases (trGTPases) are an integral part of the 'core set' of essential translational factors, and are some of the most conserved proteins across life. This study takes advantage of the wealth of available genomic data, along with novel functional information that has come to light for a number of trGTPases to address the full evolutionary and functional diversity of this superfamily across all domains of life. RESULTS Through sensitive sequence searching combined with phylogenetic analysis, 57 distinct subfamilies of trGTPases are identified: 14 bacterial, 7 archaeal and 35 eukaryotic (of which 21 are known or predicted to be organellar). The results uncover the functional evolution of trGTPases from before the last common ancestor of life on earth to the current day. CONCLUSIONS While some trGTPases are universal, others are limited to certain taxa, suggesting lineage-specific translational control mechanisms that exist on a base of core factors. These lineage-specific features may give organisms the ability to tune their translation machinery to respond to their environment. Only a fraction of the diversity of the trGTPase superfamily has been subjected to experimental analyses; this comprehensive classification brings to light novel and overlooked translation factors that are worthy of further investigation.
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31
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O’Connor M. Interactions of release factor RF3 with the translation machinery. Mol Genet Genomics 2015; 290:1335-44. [DOI: 10.1007/s00438-015-0994-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
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32
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Moghal A, Mohler K, Ibba M. Mistranslation of the genetic code. FEBS Lett 2014; 588:4305-10. [PMID: 25220850 DOI: 10.1016/j.febslet.2014.08.035] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2014] [Revised: 08/28/2014] [Accepted: 08/29/2014] [Indexed: 01/02/2023]
Abstract
During mRNA decoding at the ribosome, deviations from stringent codon identity, or "mistranslation," are generally deleterious and infrequent. Observations of organisms that decode some codons ambiguously, and the discovery of a compensatory increase in mistranslation frequency to combat environmental stress have changed the way we view "errors" in decoding. Modern tools for the study of the frequency and phenotypic effects of mistranslation can provide quantitative and sensitive measurements of decoding errors that were previously inaccessible. Mistranslation with non-protein amino acids, in particular, is an enticing prospect for new drug therapies and the study of molecular evolution.
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Affiliation(s)
- Adil Moghal
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210-1292, USA; Department of Microbiology, The Ohio State University, Columbus, OH 43210-1292, USA
| | - Kyle Mohler
- Department of Microbiology, The Ohio State University, Columbus, OH 43210-1292, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210-1292, USA
| | - Michael Ibba
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210-1292, USA; Department of Microbiology, The Ohio State University, Columbus, OH 43210-1292, USA; Center for RNA Biology, The Ohio State University, Columbus, OH 43210-1292, USA.
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33
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Petropoulos AD, McDonald ME, Green R, Zaher HS. Distinct roles for release factor 1 and release factor 2 in translational quality control. J Biol Chem 2014; 289:17589-96. [PMID: 24798339 DOI: 10.1074/jbc.m114.564989] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In bacteria, stop codons are recognized by two similar class 1 release factors, release factor 1 (RF1) and release factor 2 (RF2). Normally, during termination, the class 2 release factor 3 (RF3), a GTPase, functions downstream of peptide release where it accelerates the dissociation of RF1/RF2 prior to ribosome recycling. In addition to their canonical function in termination, both classes of release factor are also involved in a post peptidyl transfer quality control (post PT QC) mechanism where the termination factors recognize mismatched (i.e. error-containing) ribosome complexes and promote premature termination. Here, using a well defined in vitro system, we explored the role of release factors in canonical termination and post PT QC. As reported previously, during canonical termination, RF1 and RF2 recognize stop codons in a similar manner, and RF3 accelerates their rate of dissociation. During post PT QC, only RF2 (and not RF1) effectively binds to mismatched ribosome complexes; and whereas the addition of RF3 to RF2 increased its rate of release on mismatched complexes, the addition of RF3 to RF1 inhibited its rate of release but increased the rate of peptidyl-tRNA dissociation. Our data strongly suggest that RF2, in addition to its primary role in peptide release, functions as the principle factor for post PT QC.
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Affiliation(s)
- Alexandros D Petropoulos
- From the Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Megan E McDonald
- From the Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Rachel Green
- From the Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205 and
| | - Hani S Zaher
- the Department of Biology, Washington University in St. Louis, St. Louis, Missouri 63130
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34
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Álvarez-Ordóñez A, Begley M, Clifford T, Deasy T, Collins B, Hill C. Transposon mutagenesis reveals genes involved in osmotic stress and drying in Cronobacter sakazakii. Food Res Int 2014. [DOI: 10.1016/j.foodres.2013.10.037] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Gupta P, Kannan K, Mankin AS, Vázquez-Laslop N. Regulation of gene expression by macrolide-induced ribosomal frameshifting. Mol Cell 2013; 52:629-42. [PMID: 24239289 DOI: 10.1016/j.molcel.2013.10.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 09/11/2013] [Accepted: 10/09/2013] [Indexed: 11/29/2022]
Abstract
The expression of many genes is controlled by upstream ORFs (uORFs). Typically, the progression of the ribosome through a regulatory uORF, which depends on the physiological state of the cell, influences the expression of the downstream gene. In the classic mechanism of induction of macrolide resistance genes, antibiotics promote translation arrest within the uORF, and the static ribosome induces a conformational change in mRNA, resulting in the activation of translation of the resistance cistron. We show that ketolide antibiotics, which do not induce ribosome stalling at the uORF of the ermC resistance gene, trigger its expression via a unique mechanism. Ketolides promote frameshifting at the uORF, allowing the translating ribosome to invade the intergenic spacer. The dynamic unfolding of the mRNA structure leads to the activation of resistance. Conceptually similar mechanisms may control other cellular genes. The identified property of ketolides to reduce the fidelity of reading frame maintenance may have medical implications.
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Affiliation(s)
- Pulkit Gupta
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
| | - Krishna Kannan
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA
| | - Alexander S Mankin
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA.
| | - Nora Vázquez-Laslop
- Center for Pharmaceutical Biotechnology, University of Illinois at Chicago, 900 South Ashland Avenue, Chicago, IL 60607, USA.
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36
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Peske F, Kuhlenkoetter S, Rodnina MV, Wintermeyer W. Timing of GTP binding and hydrolysis by translation termination factor RF3. Nucleic Acids Res 2013; 42:1812-20. [PMID: 24214994 PMCID: PMC3919579 DOI: 10.1093/nar/gkt1095] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Protein synthesis in bacteria is terminated by release factors 1 or 2 (RF1/2), which, on recognition of a stop codon in the decoding site on the ribosome, promote the hydrolytic release of the polypeptide from the transfer RNA (tRNA). Subsequently, the dissociation of RF1/2 is accelerated by RF3, a guanosine triphosphatase (GTPase) that hydrolyzes GTP during the process. Here we show that—in contrast to a previous report—RF3 binds GTP and guanosine diphosphate (GDP) with comparable affinities. Furthermore, we find that RF3–GTP binds to the ribosome and hydrolyzes GTP independent of whether the P site contains peptidyl-tRNA (pre-termination state) or deacylated tRNA (post-termination state). RF3–GDP in either pre- or post-termination complexes readily exchanges GDP for GTP, and the exchange is accelerated when RF2 is present on the ribosome. Peptide release results in the stabilization of the RF3–GTP–ribosome complex, presumably due to the formation of the hybrid/rotated state of the ribosome, thereby promoting the dissociation of RF1/2. GTP hydrolysis by RF3 is virtually independent of the functional state of the ribosome and the presence of RF2, suggesting that RF3 acts as an unregulated ribosome-activated switch governed by its internal GTPase clock.
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Affiliation(s)
- Frank Peske
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
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37
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Eyler DE, Wehner KA, Green R. Eukaryotic release factor 3 is required for multiple turnovers of peptide release catalysis by eukaryotic release factor 1. J Biol Chem 2013; 288:29530-8. [PMID: 23963452 PMCID: PMC3795251 DOI: 10.1074/jbc.m113.487090] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Eukaryotic peptide release factor 3 (eRF3) is a conserved, essential gene in eukaryotes implicated in translation termination. We have systematically measured the contribution of eRF3 to the rates of peptide release with both saturating and limiting levels of eukaryotic release factor 1 (eRF1). Although eRF3 modestly stimulates the absolute rate of peptide release (∼5-fold), it strongly increases the rate of peptide release when eRF1 is limiting (>20-fold). This effect was generalizable across all stop codons and in a variety of contexts. Further investigation revealed that eRF1 remains associated with ribosomal complexes after peptide release and subunit dissociation and that eRF3 promotes the dissociation of eRF1 from these post-termination complexes. These data are consistent with models where eRF3 principally affects binding interactions between eRF1 and the ribosome, either prior to or subsequent to peptide release. A role for eRF3 as an escort for eRF1 into its fully accommodated state is easily reconciled with its close sequence similarity to the translational GTPase EFTu.
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Affiliation(s)
- Daniel E Eyler
- From the Howard Hughes Medical Institute and the Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
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38
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Firth AE, Jagger BW, Wise HM, Nelson CC, Parsawar K, Wills NM, Napthine S, Taubenberger JK, Digard P, Atkins JF. Ribosomal frameshifting used in influenza A virus expression occurs within the sequence UCC_UUU_CGU and is in the +1 direction. Open Biol 2013; 2:120109. [PMID: 23155484 PMCID: PMC3498833 DOI: 10.1098/rsob.120109] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 10/04/2012] [Indexed: 01/13/2023] Open
Abstract
Programmed ribosomal frameshifting is used in the expression of many virus genes and some cellular genes. In eukaryotic systems, the most well-characterized mechanism involves -1 tandem tRNA slippage on an X_XXY_YYZ motif. By contrast, the mechanisms involved in programmed +1 (or -2) slippage are more varied and often poorly characterized. Recently, a novel gene, PA-X, was discovered in influenza A virus and found to be expressed via a shift to the +1 reading frame. Here, we identify, by mass spectrometric analysis, both the site (UCC_UUU_CGU) and direction (+1) of the frameshifting that is involved in PA-X expression. Related sites are identified in other virus genes that have previously been proposed to be expressed via +1 frameshifting. As these viruses infect insects (chronic bee paralysis virus), plants (fijiviruses and amalgamaviruses) and vertebrates (influenza A virus), such motifs may form a new class of +1 frameshift-inducing sequences that are active in diverse eukaryotes.
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Affiliation(s)
- A E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Cambridge CB2 1QP, UK
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39
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Acosta-Silva C, Bertran J, Branchadell V, Oliva A. Quantum Mechanical Study on the Mechanism of Peptide Release in the Ribosome. J Phys Chem B 2013; 117:3503-15. [DOI: 10.1021/jp3110248] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Carles Acosta-Silva
- Departament de Química, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
| | - Joan Bertran
- Departament de Química, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
| | - Vicenç Branchadell
- Departament de Química, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
| | - Antoni Oliva
- Departament de Química, Universitat Autònoma
de Barcelona, 08193 Bellaterra, Spain
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40
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Environmental perturbations lift the degeneracy of the genetic code to regulate protein levels in bacteria. Proc Natl Acad Sci U S A 2012; 110:2419-24. [PMID: 23277573 DOI: 10.1073/pnas.1211077110] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The genetic code underlying protein synthesis is a canonical example of a degenerate biological system. Degeneracies in physical and biological systems can be lifted by external perturbations, thus allowing degenerate systems to exhibit a wide range of behaviors. Here we show that the degeneracy of the genetic code is lifted by environmental perturbations to regulate protein levels in living cells. By measuring protein synthesis rates from a synthetic reporter library in Escherichia coli, we find that environmental perturbations, such as reduction of cognate amino acid supply, lift the degeneracy of the genetic code by splitting codon families into a hierarchy of robust and sensitive synonymous codons. Rates of protein synthesis associated with robust codons are up to 100-fold higher than those associated with sensitive codons under these conditions. We find that the observed hierarchy between synonymous codons is not determined by usual rules associated with tRNA abundance and codon usage. Rather, competition among tRNA isoacceptors for aminoacylation underlies the robustness of protein synthesis. Remarkably, the hierarchy established using the synthetic library also explains the measured robustness of synthesis for endogenous proteins in E. coli. We further found that the same hierarchy is reflected in the fitness cost of synonymous mutations in amino acid biosynthesis genes and in the transcriptional control of σ-factor genes. Our study suggests that organisms can exploit degeneracy lifting as a general strategy to adapt protein synthesis to their environment.
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41
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Franckenberg S, Becker T, Beckmann R. Structural view on recycling of archaeal and eukaryotic ribosomes after canonical termination and ribosome rescue. Curr Opin Struct Biol 2012; 22:786-96. [DOI: 10.1016/j.sbi.2012.08.002] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2012] [Revised: 07/26/2012] [Accepted: 08/05/2012] [Indexed: 11/29/2022]
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42
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Chadani Y, Ito K, Kutsukake K, Abo T. ArfA recruits release factor 2 to rescue stalled ribosomes by peptidyl-tRNA hydrolysis inEscherichia coli. Mol Microbiol 2012; 86:37-50. [DOI: 10.1111/j.1365-2958.2012.08190.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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Dever TE, Green R. The elongation, termination, and recycling phases of translation in eukaryotes. Cold Spring Harb Perspect Biol 2012; 4:a013706. [PMID: 22751155 DOI: 10.1101/cshperspect.a013706] [Citation(s) in RCA: 281] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
This work summarizes our current understanding of the elongation and termination/recycling phases of eukaryotic protein synthesis. We focus here on recent advances in the field. In addition to an overview of translation elongation, we discuss unique aspects of eukaryotic translation elongation including eEF1 recycling, eEF2 modification, and eEF3 and eIF5A function. Likewise, we highlight the function of the eukaryotic release factors eRF1 and eRF3 in translation termination, and the functions of ABCE1/Rli1, the Dom34:Hbs1 complex, and Ligatin (eIF2D) in ribosome recycling. Finally, we present some of the key questions in translation elongation, termination, and recycling that remain to be answered.
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Affiliation(s)
- Thomas E Dever
- Laboratory of Gene Regulation and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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44
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McDonald ME, Green R. Another burst of smoke: atomic resolution structures of RF3 bound to the ribosome. RNA (NEW YORK, N.Y.) 2012; 18:605-609. [PMID: 22345149 PMCID: PMC3312549 DOI: 10.1261/rna.032011.111] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Two recent reports provide atomic resolution information detailing the interaction of the class II release factor, RF3, with the bacterial ribosome. Differences in the composition of the two crystal forms allow us to learn a considerable amount about how translational GTPases engage the ribosome to facilitate and define conformational rearrangements involved in protein synthesis.
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Affiliation(s)
- Megan E. McDonald
- Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
| | - Rachel Green
- Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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45
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Petropoulos AD, Green R. Further in vitro exploration fails to support the allosteric three-site model. J Biol Chem 2012; 287:11642-8. [PMID: 22378789 PMCID: PMC3320913 DOI: 10.1074/jbc.c111.330068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Ongoing debate in the ribosome field has focused on the role of bound E-site tRNA and the Shine-Dalgarno-anti-Shine-Dalgarno (SD-aSD) interaction on A-site tRNA interactions and the fidelity of tRNA selection. Here we use an in vitro reconstituted Escherichia coli translation system to explore the reported effects of E-site-bound tRNA and SD-aSD interactions on tRNA selection events and find no evidence for allosteric coupling. A large set of experiments exploring the role of the E-site tRNA in miscoding failed to recapitulate the observations of earlier studies (Di Giacco, V., Márquez, V., Qin, Y., Pech, M., Triana-Alonso, F. J., Wilson, D. N., and Nierhaus, K. H. (2008) Proc. Natl. Acad. Sci. U.S.A. 105, 10715-10720 and Geigenmüller, U., and Nierhaus, K. H. (1990) EMBO J. 9, 4527-4533); the frequency of miscoding was unaffected by the presence of E-site-bound cognate tRNA. Moreover, our data provide clear evidence that the reported effects of the SD-aSD interaction on fidelity can be attributed to the binding of ribosomes to an unanticipated site on the mRNA (in the absence of the SD sequence) that provides a cognate pairing codon leading naturally to incorporation of the purported "noncognate" amino acid.
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Affiliation(s)
- Alexandros D Petropoulos
- Howard Hughes Medical Institute, Department of Molecular Biology and Genetics, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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Vivanco-Domínguez S, Bueno-Martínez J, León-Avila G, Iwakura N, Kaji A, Kaji H, Guarneros G. Protein synthesis factors (RF1, RF2, RF3, RRF, and tmRNA) and peptidyl-tRNA hydrolase rescue stalled ribosomes at sense codons. J Mol Biol 2012; 417:425-39. [PMID: 22326347 DOI: 10.1016/j.jmb.2012.02.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Revised: 01/17/2012] [Accepted: 02/03/2012] [Indexed: 10/14/2022]
Abstract
During translation, ribosomes stall on mRNA when the aminoacyl-tRNA to be read is not readily available. The stalled ribosomes are deleterious to the cell and should be rescued to maintain its viability. To investigate the contribution of some of the cellular translation factors on ribosome rescuing, we provoked stalling at AGA codons in mutants that affected the factors and then analyzed the accumulation of oligopeptidyl (peptides of up to 6 amino acid residues, oligopep-)-tRNA or polypeptidyl (peptides of more than 300 amino acids in length, polypep-)-tRNA associated with ribosomes. Stalling was achieved by starvation for aminoacyl-tRNA(Arg4) upon induced expression of engineered lacZ (β-galactosidase) reporter gene harboring contiguous AGA codons close to the initiation codon or at internal codon positions together with minigene ATGAGATAA accompanied by reduced peptidyl-tRNA hydrolase (Pth). Our results showed accumulations of peptidyl-tRNA associated with ribosomes in mutants for release factors (RF1, RF2, and RF3), ribosome recycling factor (RRF), Pth, and transfer-messenger RNA (tmRNA), implying that each of these factors cooperate in rescuing stalled ribosomes. The role of these factors in ribosome releasing from the stalled complex may vary depending on the length of the peptide in the peptidyl-tRNA. RF3 and RRF rescue stalled ribosomes by "drop-off" of peptidyl-tRNA, while RF1, RF2 (in the absence of termination codon), or Pth may rescue by hydrolyzing the associated peptidyl-tRNA. This is followed by the disassembly of the ribosomal complex of tRNA and mRNA by RRF and elongation factor G.
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Affiliation(s)
- Serafín Vivanco-Domínguez
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, P.O. Box 14-740, Mexico City, 07000, Mexico
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Quality control of mRNA decoding on the bacterial ribosome. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 86:95-128. [PMID: 22243582 DOI: 10.1016/b978-0-12-386497-0.00003-7] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The ribosome is a major player in providing accurate gene expression in the cell. The fidelity of substrate selection is tightly controlled throughout the translation process, including the initiation, elongation, and termination phases. Although each phase of translation involves different players, that is, translation factors and tRNAs, the general principles of selection appear surprisingly similar for very different substrates. At essentially every step of translation, differences in complex stabilities as well as induced fit are sources of selectivity. A view starts to emerge of how the ribosome uses local and global conformational switches to govern induced-fit mechanisms that ensure fidelity. This review describes the mechanisms of tRNA and mRNA selection at all phases of protein synthesis in bacteria.
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