1
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Shuvalov A, Klishin A, Biziaev N, Shuvalova E, Alkalaeva E. Functional Activity of Isoform 2 of Human eRF1. Int J Mol Sci 2024; 25:7997. [PMID: 39063238 PMCID: PMC11277123 DOI: 10.3390/ijms25147997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2024] [Revised: 06/29/2024] [Accepted: 07/12/2024] [Indexed: 07/28/2024] Open
Abstract
Eukaryotic release factor eRF1, encoded by the ETF1 gene, recognizes stop codons and induces peptide release during translation termination. ETF1 produces several different transcripts as a result of alternative splicing, from which two eRF1 isoforms can be formed. Isoform 1 codes well-studied canonical eRF1, and isoform 2 is 33 amino acid residues shorter than isoform 1 and completely unstudied. Using a reconstituted mammalian in vitro translation system, we showed that the isoform 2 of human eRF1 is also involved in translation. We showed that eRF1iso2 can interact with the ribosomal subunits and pre-termination complex. However, its codon recognition and peptide release activities have decreased. Additionally, eRF1 isoform 2 exhibits unipotency to UGA. We found that eRF1 isoform 2 interacts with eRF3a but stimulated its GTPase activity significantly worse than the main isoform eRF1. Additionally, we studied the eRF1 isoform 2 effect on stop codon readthrough and translation in a cell-free translation system. We observed that eRF1 isoform 2 suppressed stop codon readthrough of the uORFs and decreased the efficiency of translation of long coding sequences. Based on these data, we assumed that human eRF1 isoform 2 can be involved in the regulation of translation termination. Moreover, our data support previously stated hypotheses that the GTS loop is important for the multipotency of eRF1 to all stop codons. Whereas helix α1 of the N-domain eRF1 is proposed to be involved in conformational rearrangements of eRF1 in the A-site of the ribosome that occur after GTP hydrolysis by eRF3, which ensure hydrolysis of peptidyl-tRNA at the P site of the ribosome.
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Affiliation(s)
- Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
| | - Alexandr Klishin
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
| | - Nikita Biziaev
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
| | - Ekaterina Shuvalova
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia; (A.S.)
- Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, The Russian Academy of Sciences, 119991 Moscow, Russia
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2
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Chang X, Qu F, Li C, Zhang J, Zhang Y, Xie Y, Fan Z, Bian J, Wang J, Li Z, Xu X. Development and therapeutic potential of GSPT1 molecular glue degraders: A medicinal chemistry perspective. Med Res Rev 2024; 44:1727-1767. [PMID: 38314926 DOI: 10.1002/med.22024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/18/2023] [Accepted: 01/21/2024] [Indexed: 02/07/2024]
Abstract
Unprecedented therapeutic targeting of previously undruggable proteins has now been achieved by molecular-glue-mediated proximity-induced degradation. As a small GTPase, G1 to S phase transition 1 (GSPT1) interacts with eRF1, the translation termination factor, to facilitate the process of translation termination. Studied demonstrated that GSPT1 plays a vital role in the acute myeloid leukemia (AML) and MYC-driven lung cancer. Thus, molecular glue (MG) degraders targeting GSPT1 is a novel and promising approach for treating AML and MYC-driven cancers. In this Perspective, we briefly summarize the structural and functional aspects of GSPT1, highlighting the latest advances and challenges in MG degraders, as well as some representative patents. The structure-activity relationships, mechanism of action and pharmacokinetic features of MG degraders are emphasized to provide a comprehensive compendium on the rational design of GSPT1 MG degraders. We hope to provide an updated overview, and design guide for strategies targeting GSPT1 for the treatment of cancer.
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Affiliation(s)
- Xiujin Chang
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Fangui Qu
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Chunxiao Li
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jingtian Zhang
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yanqing Zhang
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Yuanyuan Xie
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Zhongpeng Fan
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jinlei Bian
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Jubo Wang
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Zhiyu Li
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xi Xu
- Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing, China
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3
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Wagner RN, Wießner M, Friedrich A, Zandanell J, Breitenbach-Koller H, Bauer JW. Emerging Personalized Opportunities for Enhancing Translational Readthrough in Rare Genetic Diseases and Beyond. Int J Mol Sci 2023; 24:6101. [PMID: 37047074 PMCID: PMC10093890 DOI: 10.3390/ijms24076101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Nonsense mutations trigger premature translation termination and often give rise to prevalent and rare genetic diseases. Consequently, the pharmacological suppression of an unscheduled stop codon represents an attractive treatment option and is of high clinical relevance. At the molecular level, the ability of the ribosome to continue translation past a stop codon is designated stop codon readthrough (SCR). SCR of disease-causing premature termination codons (PTCs) is minimal but small molecule interventions, such as treatment with aminoglycoside antibiotics, can enhance its frequency. In this review, we summarize the current understanding of translation termination (both at PTCs and at cognate stop codons) and highlight recently discovered pathways that influence its fidelity. We describe the mechanisms involved in the recognition and readthrough of PTCs and report on SCR-inducing compounds currently explored in preclinical research and clinical trials. We conclude by reviewing the ongoing attempts of personalized nonsense suppression therapy in different disease contexts, including the genetic skin condition epidermolysis bullosa.
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Affiliation(s)
- Roland N. Wagner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Michael Wießner
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | - Andreas Friedrich
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
- Department of Biosciences, University of Salzburg, 5020 Salzburg, Austria
| | - Johanna Zandanell
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
| | | | - Johann W. Bauer
- Department of Dermatology and Allergology, University Hospital of the Paracelsus Medical University, 5020 Salzburg, Austria
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4
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Biziaev N, Sokolova E, Yanvarev DV, Toropygin IY, Shuvalov A, Egorova T, Alkalaeva E. Recognition of 3' nucleotide context and stop codon readthrough are determined during mRNA translation elongation. J Biol Chem 2022; 298:102133. [PMID: 35700825 PMCID: PMC9272376 DOI: 10.1016/j.jbc.2022.102133] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 06/06/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
The nucleotide context surrounding stop codons significantly affects the efficiency of translation termination. In eukaryotes, various 3′ contexts that are unfavorable for translation termination have been described; however, the exact molecular mechanism that mediates their effects remains unknown. In this study, we used a reconstituted mammalian translation system to examine the efficiency of stop codons in different contexts, including several previously described weak 3′ stop codon contexts. We developed an approach to estimate the level of stop codon readthrough in the absence of eukaryotic release factors (eRFs). In this system, the stop codon is recognized by the suppressor or near-cognate tRNAs. We observed that in the absence of eRFs, readthrough occurs in a 3′ nucleotide context-dependent manner, and the main factors determining readthrough efficiency were the type of stop codon and the sequence of the 3′ nucleotides. Moreover, the efficiency of translation termination in weak 3′ contexts was almost equal to that in the tested standard context. Therefore, the ability of eRFs to recognize stop codons and induce peptide release is not affected by mRNA context. We propose that ribosomes or other participants of the elongation cycle can independently recognize certain contexts and increase the readthrough of stop codons. Thus, the efficiency of translation termination is regulated by the 3′ nucleotide context following the stop codon and depends on the concentrations of eRFs and suppressor/near-cognate tRNAs.
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Affiliation(s)
- Nikita Biziaev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Elizaveta Sokolova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Dmitry V Yanvarev
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Ilya Yu Toropygin
- Orekhovich Research Institute of Biomedical Chemistry, Moscow, 119992, Russia.
| | - Alexey Shuvalov
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
| | - Tatiana Egorova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, 117997, Russia.
| | - Elena Alkalaeva
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia; Center for Precision Genome Editing and Genetic Technologies for Biomedicine, Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 119991 Moscow, Russia.
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5
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Fu X, Huang Y, Shen Y. Improving the Efficiency and Orthogonality of Genetic Code Expansion. BIODESIGN RESEARCH 2022; 2022:9896125. [PMID: 37850140 PMCID: PMC10521639 DOI: 10.34133/2022/9896125] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 05/20/2022] [Indexed: 10/19/2023] Open
Abstract
The site-specific incorporation of the noncanonical amino acid (ncAA) into proteins via genetic code expansion (GCE) has enabled the development of new and powerful ways to learn, regulate, and evolve biological functions in vivo. However, cellular biosynthesis of ncAA-containing proteins with high efficiency and fidelity is a formidable challenge. In this review, we summarize up-to-date progress towards improving the efficiency and orthogonality of GCE and enhancing intracellular compatibility of introduced translation machinery in the living cells by creation and optimization of orthogonal translation components, constructing genomically recoded organism (GRO), utilization of unnatural base pairs (UBP) and quadruplet codons (four-base codons), and spatial separation of orthogonal translation.
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Affiliation(s)
- Xian Fu
- BGI-Shenzhen, Shenzhen 518083, China
- Guangdong Provincial Key Laboratory of Genome Read and Write, Shenzhen 518120China
| | - Yijian Huang
- BGI-Shenzhen, Shenzhen 518083, China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yue Shen
- BGI-Shenzhen, Shenzhen 518083, China
- Guangdong Provincial Key Laboratory of Genome Read and Write, Shenzhen 518120China
- Shenzhen Institute of Synthetic Biology, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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6
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Smith PR, Pandit SC, Loerch S, Campbell ZT. The space between notes: emerging roles for translationally silent ribosomes. Trends Biochem Sci 2022; 47:477-491. [PMID: 35246374 PMCID: PMC9106873 DOI: 10.1016/j.tibs.2022.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/31/2022] [Accepted: 02/04/2022] [Indexed: 01/02/2023]
Abstract
In addition to their central functions in translation, ribosomes can adopt inactive structures that are fully assembled yet devoid of mRNA. We describe how the abundance of idle eukaryotic ribosomes is influenced by a broad range of biological conditions spanning viral infection, nutrient deprivation, and developmental cues. Vacant ribosomes may provide a means to exclude ribosomes from translation while also shielding them from degradation, and the variable identity of factors that occlude ribosomes may impart distinct functionality. We propose that regulated changes in the balance of idle and active ribosomes provides a means to fine-tune translation. We provide an overview of idle ribosomes, describe what is known regarding their function, and highlight questions that may clarify their biological roles.
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Affiliation(s)
- Patrick R Smith
- The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX, USA
| | - Sapna C Pandit
- University of California, Santa Cruz, Department of Chemistry and Biochemistry, Santa Cruz, CA, USA
| | - Sarah Loerch
- University of California, Santa Cruz, Department of Chemistry and Biochemistry, Santa Cruz, CA, USA
| | - Zachary T Campbell
- The University of Texas at Dallas, Department of Biological Sciences, Richardson, TX, USA; The Center for Advanced Pain Studies (CAPS), University of Texas at Dallas, Richardson, TX, USA.
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7
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Blanchet S, Ranjan N. Translation Phases in Eukaryotes. Methods Mol Biol 2022; 2533:217-228. [PMID: 35796991 PMCID: PMC9761538 DOI: 10.1007/978-1-0716-2501-9_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Protein synthesis in eukaryotes is carried out by 80S ribosomes with the help of many specific translation factors. Translation comprises four major steps: initiation, elongation, termination, and ribosome recycling. In this review, we provide a comprehensive list of translation factors required for protein synthesis in yeast and higher eukaryotes and summarize the mechanisms of each individual phase of eukaryotic translation.
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Affiliation(s)
- Sandra Blanchet
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
| | - Namit Ranjan
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany.
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8
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Bulygin KN, Timofeev IO, Malygin AA, Graifer DM, Meschaninova MI, Venyaminova AG, Krumkacheva OA, Fedin MV, Yu Frolova L, Karpova GG, Bagryanskaya EG. Two alternative conformations of mRNA in the human ribosome during elongation and termination of translation as revealed by EPR spectroscopy. Comput Struct Biotechnol J 2021; 19:4702-4710. [PMID: 34504663 PMCID: PMC8390954 DOI: 10.1016/j.csbj.2021.08.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 08/12/2021] [Accepted: 08/16/2021] [Indexed: 11/29/2022] Open
Abstract
DEER reveals the conformational variability of mRNA at the certain translation steps. Elongation and termination complexes exist in 2 conformations in dynamic equilibrium. The conformations of mRNA in 40S channel undergo no major change during termination.
The conformation of mRNA in the region of the human 80S ribosome decoding site was monitored using 11-mer mRNA analogues that bore nitroxide spin labels attached to the terminal nucleotide bases. Intramolecular spin–spin distances were measured by DEER/PELDOR spectroscopy in model complexes mimicking different states of the 80S ribosome during elongation and termination of translation. The measurements revealed that in all studied complexes, mRNA exists in two alternative conformations, whose ratios are different in post-translocation, pre-translocation and termination complexes. We found that the presence of a tRNA molecule at the ribosomal A site decreases the relative share of the more extended mRNA conformation, whereas the binding of eRF1 (alone or in a complex with eRF3) results in the opposite effect. In the termination complexes, the ratios of mRNA conformations are practically the same, indicating that a part of mRNA bound in the ribosome channel does not undergo significant structural alterations in the course of completion of the translation. Our results contribute to the understanding of mRNA molecular dynamics in the mammalian ribosome channel during translation.
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Affiliation(s)
- Konstantin N Bulygin
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Ivan O Timofeev
- International Tomography Center SB RAS, Institutskaya Str. 3a, Novosibirsk 630090, Russia
| | - Alexey A Malygin
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Dmitri M Graifer
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Maria I Meschaninova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Alya G Venyaminova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Olesya A Krumkacheva
- International Tomography Center SB RAS, Institutskaya Str. 3a, Novosibirsk 630090, Russia
| | - Matvey V Fedin
- International Tomography Center SB RAS, Institutskaya Str. 3a, Novosibirsk 630090, Russia
| | - Ludmila Yu Frolova
- Engelhardt Institute of Molecular Biology RAS, Vavilova Str. 32, Moscow 119991, Russia
| | - Galina G Karpova
- Institute of Chemical Biology and Fundamental Medicine SB RAS, pr. Lavrentjeva 8, Novosibirsk 630090, Russia
| | - Elena G Bagryanskaya
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, pr. Lavrentjeva 9, Novosibirsk 630090, Russia
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9
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Li F, Yang G, Tachikawa H, Shao K, Yang Y, Gao XD, Nakanishi H. Identification of novel O-GlcNAc transferase substrates using yeast cells expressing OGT. J GEN APPL MICROBIOL 2020; 67:33-41. [PMID: 33229814 DOI: 10.2323/jgam.2020.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
O-GlcNAc modification mediated by O-GlcNAc transferase (OGT) is a reversible protein modification in which O-GlcNAc moieties are attached to target proteins in the cytosol, nucleus, and mitochondria. O-GlcNAc moieties attached to proteins can be removed by O-GlcNAcase (OGA). The addition of an O-GlcNAc moiety can influence several aspects of protein function, and aberrant O-GlcNAc modification is linked to a number of diseases. While OGT and OGA are conserved across eukaryotic cells, yeasts lack these enzymes. Previously, we reported that protein O-GlcNAc modification occurred in the budding yeast Saccharomyces cerevisiae when OGT was ectopically expressed. Because yeast cells lack OGA, O-GlcNAc moieties are stably attached to target proteins. Thus, the yeast system may be useful for finding novel OST substrates. By proteomic analysis, we identified 468 O-GlcNAcylated proteins in yeast cells expressing human OGT. Among these proteins, 13 have human orthologues that show more than 30% identity to their corresponding yeast orthologue, and possible glycosylation residues are conserved in these human orthologues. In addition, the orthologues have not been reported as substrates of OGT. We verified that some of these human orthologues are O-GlcNAcylated in cultured human cells. These proteins include an ubiquitin-conjugating enzyme, UBE2D1, and an eRF3-similar protein, HBS1L. Thus, the yeast system would be useful to find previously unknown O-GlcNAcylated proteins and regulatory mechanisms.
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Affiliation(s)
- Feng Li
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Ganglong Yang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Hiroyuki Tachikawa
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo.,Collaborative Research Institute for Innovative Microbiology, The University of Tokyo
| | - Kankai Shao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Yan Yang
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Xiao-Dong Gao
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
| | - Hideki Nakanishi
- Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University
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10
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Beißel C, Grosse S, Krebber H. Dbp5/DDX19 between Translational Readthrough and Nonsense Mediated Decay. Int J Mol Sci 2020; 21:ijms21031085. [PMID: 32041247 PMCID: PMC7037193 DOI: 10.3390/ijms21031085] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 01/31/2020] [Accepted: 02/02/2020] [Indexed: 01/21/2023] Open
Abstract
The DEAD-box protein Dbp5 (human DDX19) remodels RNA-protein complexes. Dbp5 functions in ribonucleoprotein export and translation termination. Termination occurs, when the ribosome has reached a stop codon through the Dbp5 mediated delivery of the eukaryotic termination factor eRF1. eRF1 contacts eRF3 upon dissociation of Dbp5, resulting in polypeptide chain release and subsequent ribosomal subunit splitting. Mutations in DBP5 lead to stop codon readthrough, because the eRF1 and eRF3 interaction is not controlled and occurs prematurely. This identifies Dbp5/DDX19 as a possible potent drug target for nonsense suppression therapy. Neurodegenerative diseases and cancer are caused in many cases by the loss of a gene product, because its mRNA contained a premature termination codon (PTC) and is thus eliminated through the nonsense mediated decay (NMD) pathway, which is described in the second half of this review. We discuss translation termination and NMD in the light of Dbp5/DDX19 and subsequently speculate on reducing Dbp5/DDX19 activity to allow readthrough of the PTC and production of a full-length protein to detract the RNA from NMD as a possible treatment for diseases.
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11
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Yang Q, Yu CH, Zhao F, Dang Y, Wu C, Xie P, Sachs MS, Liu Y. eRF1 mediates codon usage effects on mRNA translation efficiency through premature termination at rare codons. Nucleic Acids Res 2019; 47:9243-9258. [PMID: 31410471 PMCID: PMC6755126 DOI: 10.1093/nar/gkz710] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/23/2019] [Accepted: 08/02/2019] [Indexed: 12/16/2022] Open
Abstract
Codon usage bias is a universal feature of eukaryotic and prokaryotic genomes and plays an important role in regulating gene expression levels. A major role of codon usage is thought to regulate protein expression levels by affecting mRNA translation efficiency, but the underlying mechanism is unclear. By analyzing ribosome profiling results, here we showed that codon usage regulates translation elongation rate and that rare codons are decoded more slowly than common codons in all codon families in Neurospora. Rare codons resulted in ribosome stalling in manners both dependent and independent of protein sequence context and caused premature translation termination. This mechanism was shown to be conserved in Drosophila cells. In both Neurospora and Drosophila cells, codon usage plays an important role in regulating mRNA translation efficiency. We found that the rare codon-dependent premature termination is mediated by the translation termination factor eRF1, which recognizes ribosomes stalled on rare sense codons. Silencing of eRF1 expression resulted in codon usage-dependent changes in protein expression. Together, these results establish a mechanism for how codon usage regulates mRNA translation efficiency.
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Affiliation(s)
- Qian Yang
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Chien-Hung Yu
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.,Department of Biochemistry and Molecular Biology, National Cheng Kung University, Tainan 701, Taiwan
| | - Fangzhou Zhao
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
| | - Yunkun Dang
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.,State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650500, China
| | - Cheng Wu
- Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA
| | - Pancheng Xie
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA.,Jiangsu Key Laboratory of Neuropsychiatric Diseases and Cambridge-Suda Genomic Resource Center, Soochow University, 199 Ren'ai Road, Suzhou, Jiangsu 215123, China
| | - Matthew S Sachs
- Department of Biology, Texas A&M University, College Station, TX 77843-3258, USA
| | - Yi Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75390, USA
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12
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Lyke DR, Dorweiler JE, Manogaran AL. The three faces of Sup35. Yeast 2019; 36:465-472. [PMID: 30963611 DOI: 10.1002/yea.3392] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 03/07/2019] [Accepted: 03/26/2019] [Indexed: 12/30/2022] Open
Abstract
Sup35p is an essential protein in yeast that functions in complex with Sup45p for efficient translation termination. Although some may argue that this function is the only important attribute of Sup35p, there are two additional known facets of Sup35p's biology that may provide equally important functions for yeast; both of which involve various strategies for coping with stress. Recently, the N-terminal and middle regions (NM) of Sup35p, which are not required for translation termination function, have been found to provide stress-sensing abilities and facilitate the phase separation of Sup35p into biomolecular condensates in response to transient stress. Interestingly, the same NM domain is also required for Sup35p to misfold and enter into aggregates associated with the [PSI+ ] prion. Here, we review these three different states or "faces" of Sup35p. For each, we compare the functionality and necessity of different Sup35p domains, including the role these domains play in facilitating interactions with important protein partners, and discuss the potential ramifications that each state affords yeast cells under varying environmental conditions.
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Affiliation(s)
- Douglas R Lyke
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Jane E Dorweiler
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
| | - Anita L Manogaran
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin
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13
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Elakhdar A, Ushijima T, Fukuda M, Yamashiro N, Kawagoe Y, Kumamaru T. Eukaryotic peptide chain release factor 1 participates in translation termination of specific cysteine-poor prolamines in rice endosperm. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 281:223-231. [PMID: 30824055 DOI: 10.1016/j.plantsci.2018.12.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 12/07/2018] [Accepted: 12/10/2018] [Indexed: 06/09/2023]
Abstract
Prolamines are alcohol-soluble proteins classified as either cysteine-poor (CysP) or cysteine-rich (CysR) based on whether they can be alcohol-extracted without or with reducing agents, respectively. In rice esp1 mutants, various CysP prolamines exhibit both reduced and normal amounts of isoelectric focusing bands, indicating that the mutation affects only certain prolamine classes. To examine the genetic regulation of CysP prolamine synthesis and accumulation, we constructed a high-resolution genetic linkage map of ESP1. The ESP1 gene was mapped to within a 20 kb region on rice chromosome 7. Sequencing analysis of annotated genes in this region revealed a single-nucleotide polymorphism within eukaryotic peptide chain release factor (eRF1), which participates in stop-codon recognition and nascent-polypeptide release from ribosomes during translation. A subsequent complementation test revealed that ESP1 encodes eRF1. We also identified UAA as the stop codon of CysP prolamines with reduced concentration in esp1 mutants. Recognition assays and microarray analysis confirmed that ESP1/eRF1 recognizes UAA/UAG, but not UGA. Our results provide convincing evidence that ESP1/eRF1 participates in the translation termination of CysP prolamines during seed development.
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Affiliation(s)
- Ammar Elakhdar
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan; Field Crops Research Institute, Agricultural Research Center, Giza 12619, Egypt
| | - Tomokazu Ushijima
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan
| | - Masako Fukuda
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan
| | - Noriko Yamashiro
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan
| | - Yasushi Kawagoe
- Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan
| | - Toshihiro Kumamaru
- Institute of Genetic Resources, Faculty of Agriculture, Kyushu University, Motooka 744, Fukuoka 819-0395, Japan.
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14
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Control of mRNA Translation by Versatile ATP-Driven Machines. Trends Biochem Sci 2018; 44:167-180. [PMID: 30527974 DOI: 10.1016/j.tibs.2018.11.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 10/29/2018] [Accepted: 11/01/2018] [Indexed: 12/13/2022]
Abstract
Translation is organized in a cycle that requires ribosomal subunits, mRNA, aminoacylated transfer RNAs, and myriad regulatory factors. As soon as translation reaches a stop codon or stall, a termination or surveillance process is launched via the release factors eRF1 or Pelota, respectively. The ATP-binding cassette (ABC) protein ABCE1 interacts with release factors and coordinates the recycling process in Eukarya and Archaea. After splitting, ABCE1 stays with the small ribosomal subunit and emerges as an integral part of translation initiation complexes. In addition, eEF3 and ABCF proteins control translation by binding at the E-site. In this review, we highlight advances in the fundamental role of ABC systems in mRNA translation in view of their collective inner mechanics.
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15
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Hellen CUT. Translation Termination and Ribosome Recycling in Eukaryotes. Cold Spring Harb Perspect Biol 2018; 10:cshperspect.a032656. [PMID: 29735640 DOI: 10.1101/cshperspect.a032656] [Citation(s) in RCA: 115] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Termination of mRNA translation occurs when a stop codon enters the A site of the ribosome, and in eukaryotes is mediated by release factors eRF1 and eRF3, which form a ternary eRF1/eRF3-guanosine triphosphate (GTP) complex. eRF1 recognizes the stop codon, and after hydrolysis of GTP by eRF3, mediates release of the nascent peptide. The post-termination complex is then disassembled, enabling its constituents to participate in further rounds of translation. Ribosome recycling involves splitting of the 80S ribosome by the ATP-binding cassette protein ABCE1 to release the 60S subunit. Subsequent dissociation of deacylated transfer RNA (tRNA) and messenger RNA (mRNA) from the 40S subunit may be mediated by initiation factors (priming the 40S subunit for initiation), by ligatin (eIF2D) or by density-regulated protein (DENR) and multiple copies in T-cell lymphoma-1 (MCT1). These events may be subverted by suppression of termination (yielding carboxy-terminally extended read-through polypeptides) or by interruption of recycling, leading to reinitiation of translation near the stop codon.
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Affiliation(s)
- Christopher U T Hellen
- Department of Cell Biology, State University of New York, Downstate Medical Center, New York, New York 11203
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16
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Cridge AG, Crowe-McAuliffe C, Mathew SF, Tate WP. Eukaryotic translational termination efficiency is influenced by the 3' nucleotides within the ribosomal mRNA channel. Nucleic Acids Res 2018; 46:1927-1944. [PMID: 29325104 PMCID: PMC5829715 DOI: 10.1093/nar/gkx1315] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2017] [Revised: 12/07/2017] [Accepted: 01/05/2018] [Indexed: 01/01/2023] Open
Abstract
When a stop codon is at the 80S ribosomal A site, there are six nucleotides (+4 to +9) downstream that are inferred to be occupying the mRNA channel. We examined the influence of these downstream nucleotides on translation termination success or failure in mammalian cells at the three stop codons. The expected hierarchy in the intrinsic fidelity of the stop codons (UAA>UAG>>UGA) was observed, with highly influential effects on termination readthrough mediated by nucleotides at position +4 and position +8. A more complex influence was observed from the nucleotides at positions +5 and +6. The weakest termination contexts were most affected by increases or decreases in the concentration of the decoding release factor (eRF1), indicating that eRF1 binding to these signals was rate-limiting. When termination efficiency was significantly reduced by cognate suppressor tRNAs, the observed influence of downstream nucleotides was maintained. There was a positive correlation between experimentally measured signal strength and frequency of the signal in eukaryotic genomes, particularly in Saccharomyces cerevisiae and Drosophila melanogaster. We propose that termination efficiency is not only influenced by interrogation of the stop signal directly by the release factor, but also by downstream ribosomal interactions with the mRNA nucleotides in the entry channel.
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Affiliation(s)
- Andrew G Cridge
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | | | - Suneeth F Mathew
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
| | - Warren P Tate
- Department of Biochemistry, University of Otago, Dunedin, Otago 9054, New Zealand
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17
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Abstract
Termination of protein synthesis on the ribosome requires that mRNA stop codons are recognized with high fidelity. This is achieved by specific release factor proteins that are very different in bacteria and eukaryotes. Hence, while there are two release factors with overlapping specificity in bacteria, the single omnipotent eRF1 release factor in eukaryotes is able to read all three stop codons. This is particularly remarkable as it is able to select three out of four combinations of purine bases in the last two codon positions. With recently determined 3D structures of eukaryotic termination complexes, it has become possible to explore the origin of eRF1 specificity by computer simulations. Here, we report molecular dynamics free energy calculations on these termination complexes, where relative eRF1 binding free energies to different cognate and near-cognate codons are evaluated. The simulations show a high and uniform discrimination against the near-cognate codons, that differ from the cognate ones by a single nucleotide, and reveal the structural mechanisms behind the precise decoding by eRF1. The eukaryotic release factor eRF1 is able to recognize the three stop codons UAA, UAG and UGA with high accuracy, while discriminating against near-cognate codons. Here the authors use molecular dynamic simulation to provide insight into the molecular basis behind the remarkable codon specificity of eRF1.
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18
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Kumar A, Basu D, Satpati P. Structure-Based Energetics of Stop Codon Recognition by Eukaryotic Release Factor. J Chem Inf Model 2017; 57:2321-2328. [PMID: 28825483 DOI: 10.1021/acs.jcim.7b00340] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
In translation termination, the eukaryotic release factor (eRF1) recognizes mRNA stop codons (UAA, UAG, or UGA) in a ribosomal A site and triggers release of the nascent polypeptide chain from P-site tRNA. eRF1 is highly selective for U in the first position and a combination of purines (except two consecutive guanines, i.e., GG) in the second and third positions. Eukaryotes decode all three stop codons with a single release factor eRF1, instead of two (RF1 and RF2), in bacteria. Furthermore, unlike bacterial RF1/RF2, eRF1 stabilizes the compact U-turn mRNA configuration in the ribosomal A site by accommodating four nucleotides instead of three. Despite the available cryo-EM structures (resolution ∼3.5-3.8 Å), the energetic principle for eRF1 selectivity toward a stop codon remains a fundamentally unsolved problem. Using cryo-EM structures of eukaryotic translation termination complexes as templates, we carried out molecular dynamics free energy simulations of cognate and near-cognate complexes to quantitatively address the energetics of stop codon recognition by eRF1. Our results suggest that eRF1 has a higher discriminatory power against sense codons, compared to that reported earlier for RF1/RF2. The compact mRNA formed specific intra-mRNA interactions, which itself contributed to stop codon specificity. Furthermore, the specificity is enhanced by the loss of protein-mRNA interactions and, most importantly, by desolvation of the incorrect codons in the near-cognate complexes. Our work provides a clue to how eRF1 discriminates between cognate and near-cognate codons during protein synthesis.
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Affiliation(s)
- Amit Kumar
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati , Guwahati 781039, Assam, India
| | - Debadrita Basu
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati , Guwahati 781039, Assam, India
| | - Priyadarshi Satpati
- Department of Biosciences and Bioengineering, Indian Institute of Technology, Guwahati , Guwahati 781039, Assam, India
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19
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Zhang Z, Xu H, Si L, Chen Y, Zhang B, Wang Y, Wu Y, Zhou X, Zhang L, Zhou D. Construction of an inducible stable cell line for efficient incorporation of unnatural amino acids in mammalian cells. Biochem Biophys Res Commun 2017; 489:490-496. [DOI: 10.1016/j.bbrc.2017.05.178] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 05/30/2017] [Indexed: 10/19/2022]
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20
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Exploring contacts of eRF1 with the 3'-terminus of the P site tRNA and mRNA stop signal in the human ribosome at various translation termination steps. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2017; 1860:782-793. [PMID: 28457996 DOI: 10.1016/j.bbagrm.2017.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Revised: 04/20/2017] [Accepted: 04/20/2017] [Indexed: 11/22/2022]
Abstract
Here we employed site-directed cross-linking with the application of tRNA and mRNA analogues bearing an oxidized ribose at the 3'-terminus to investigate mutual arrangement of the main components of translation termination complexes formed on the human 80S ribosome bound with P site deacylated tRNA using eRF1•eRF3•GTP or eRF1 alone. In addition, we applied a model complex obtained in the same way with eRF1•eRF3•GMPPNP. We found that eRF3 content in the complexes with GTP and GMPPNP is similar, proving that eRF3 does not leave the ribosome after GTP hydrolysis. Our cross-linking data allowed determining locations of the 3'-terminus of the P site tRNA relatively the eRF1 M domain and of the mRNA stop signal toward the N domain and the ribosomal decoding site at the nucleotide-peptide resolution level. Our results indicate that locations of these components do not change after peptide release up to post-termination pre-recycling state, and the positioning of the mRNA stop signal remains similar to that when eRF1 recognizes it. Besides, we found that in all the complexes studied eRF1 shielded the N-terminal part of ribosomal protein eS30 from the interaction with the nucleotide adjacent to stop codon observed with pre-termination ribosome free of eRFs. Altogether, our findings brought important information on contacts of the key structural elements of eRF1, tRNA and mRNA in the ribosomal complexes including those mimicking different translation termination steps, thereby providing a deeper understanding of molecular mechanisms underlying events occurring in the course of protein synthesis termination in mammals.
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21
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Mechanism and Regulation of Protein Synthesis in Saccharomyces cerevisiae. Genetics 2017; 203:65-107. [PMID: 27183566 DOI: 10.1534/genetics.115.186221] [Citation(s) in RCA: 93] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/24/2016] [Indexed: 12/18/2022] Open
Abstract
In this review, we provide an overview of protein synthesis in the yeast Saccharomyces cerevisiae The mechanism of protein synthesis is well conserved between yeast and other eukaryotes, and molecular genetic studies in budding yeast have provided critical insights into the fundamental process of translation as well as its regulation. The review focuses on the initiation and elongation phases of protein synthesis with descriptions of the roles of translation initiation and elongation factors that assist the ribosome in binding the messenger RNA (mRNA), selecting the start codon, and synthesizing the polypeptide. We also examine mechanisms of translational control highlighting the mRNA cap-binding proteins and the regulation of GCN4 and CPA1 mRNAs.
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22
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Pánek T, Žihala D, Sokol M, Derelle R, Klimeš V, Hradilová M, Zadrobílková E, Susko E, Roger AJ, Čepička I, Eliáš M. Nuclear genetic codes with a different meaning of the UAG and the UAA codon. BMC Biol 2017; 15:8. [PMID: 28193262 PMCID: PMC5304391 DOI: 10.1186/s12915-017-0353-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/23/2017] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Departures from the standard genetic code in eukaryotic nuclear genomes are known for only a handful of lineages and only a few genetic code variants seem to exist outside the ciliates, the most creative group in this regard. Most frequent code modifications entail reassignment of the UAG and UAA codons, with evidence for at least 13 independent cases of a coordinated change in the meaning of both codons. However, no change affecting each of the two codons separately has been documented, suggesting the existence of underlying evolutionary or mechanistic constraints. RESULTS Here, we present the discovery of two new variants of the nuclear genetic code, in which UAG is translated as an amino acid while UAA is kept as a termination codon (along with UGA). The first variant occurs in an organism noticed in a (meta)transcriptome from the heteropteran Lygus hesperus and demonstrated to be a novel insect-dwelling member of Rhizaria (specifically Sainouroidea). This first documented case of a rhizarian with a non-canonical genetic code employs UAG to encode leucine and represents an unprecedented change among nuclear codon reassignments. The second code variant was found in the recently described anaerobic flagellate Iotanema spirale (Metamonada: Fornicata). Analyses of transcriptomic data revealed that I. spirale uses UAG to encode glutamine, similarly to the most common variant of a non-canonical code known from several unrelated eukaryotic groups, including hexamitin diplomonads (also a lineage of fornicates). However, in these organisms, UAA also encodes glutamine, whereas it is the primary termination codon in I. spirale. Along with phylogenetic evidence for distant relationship of I. spirale and hexamitins, this indicates two independent genetic code changes in fornicates. CONCLUSIONS Our study documents, for the first time, that evolutionary changes of the meaning of UAG and UAA codons in nuclear genomes can be decoupled and that the interpretation of the two codons by the cytoplasmic translation apparatus is mechanistically separable. The latter conclusion has interesting implications for possibilities of genetic code engineering in eukaryotes. We also present a newly developed generally applicable phylogeny-informed method for inferring the meaning of reassigned codons.
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Affiliation(s)
- Tomáš Pánek
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - David Žihala
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Martin Sokol
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Romain Derelle
- Unité d'Ecologie, Systématique et Evolution, Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud/Paris-Saclay, AgroParisTech, Orsay, France
| | - Vladimír Klimeš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic
| | - Miluše Hradilová
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Vídeňská 1083, 142 20, Prague, Czech Republic
| | - Eliška Zadrobílková
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague, Czech Republic
| | - Edward Susko
- Department of Mathematics and Statistics, Dalhousie University, Halifax, NS, B3H 4R2, Canada
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
| | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Dalhousie University, Halifax, NS, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, NS, B3H 4R2, Canada
- Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Toronto, ON, Canada
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Viničná 7, 128 00, Prague, Czech Republic
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, Chittussiho 10, 710 00, Ostrava, Czech Republic.
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23
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Dabrowski M, Bukowy-Bieryllo Z, Zietkiewicz E. Translational readthrough potential of natural termination codons in eucaryotes--The impact of RNA sequence. RNA Biol 2016; 12:950-8. [PMID: 26176195 PMCID: PMC4615788 DOI: 10.1080/15476286.2015.1068497] [Citation(s) in RCA: 129] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Termination of protein synthesis is not 100% efficient. A number of natural mechanisms that suppress translation termination exist. One of them is STOP codon readthrough, the process that enables the ribosome to pass through the termination codon in mRNA and continue translation to the next STOP codon in the same reading frame. The efficiency of translational readthrough depends on a variety of factors, including the identity of the termination codon, the surrounding mRNA sequence context, and the presence of stimulating compounds. Understanding the interplay between these factors provides the necessary background for the efficient application of the STOP codon suppression approach in the therapy of diseases caused by the presence of premature termination codons.
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Affiliation(s)
- Maciej Dabrowski
- a Institute of Human Genetics; Polish Academy of Sciences ; Poznan , Poland
| | | | - Ewa Zietkiewicz
- a Institute of Human Genetics; Polish Academy of Sciences ; Poznan , Poland
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24
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Drozdova PB, Tarasov OV, Matveenko AG, Radchenko EA, Sopova JV, Polev DE, Inge-Vechtomov SG, Dobrynin PV. Genome Sequencing and Comparative Analysis of Saccharomyces cerevisiae Strains of the Peterhof Genetic Collection. PLoS One 2016; 11:e0154722. [PMID: 27152522 PMCID: PMC4859572 DOI: 10.1371/journal.pone.0154722] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 04/18/2016] [Indexed: 01/09/2023] Open
Abstract
The Peterhof genetic collection of Saccharomyces cerevisiae strains (PGC) is a large laboratory stock that has accumulated several thousands of strains for over than half a century. It originated independently of other common laboratory stocks from a distillery lineage (race XII). Several PGC strains have been extensively used in certain fields of yeast research but their genomes have not been thoroughly explored yet. Here we employed whole genome sequencing to characterize five selected PGC strains including one of the closest to the progenitor, 15V-P4, and several strains that have been used to study translation termination and prions in yeast (25-25-2V-P3982, 1B-D1606, 74-D694, and 6P-33G-D373). The genetic distance between the PGC progenitor and S288C is comparable to that between two geographically isolated populations. The PGC seems to be closer to two bakery strains than to S288C-related laboratory stocks or European wine strains. In genomes of the PGC strains, we found several loci which are absent from the S288C genome; 15V-P4 harbors a rare combination of the gene cluster characteristic for wine strains and the RTM1 cluster. We closely examined known and previously uncharacterized gene variants of particular strains and were able to establish the molecular basis for known phenotypes including phenylalanine auxotrophy, clumping behavior and galactose utilization. Finally, we made sequencing data and results of the analysis available for the yeast community. Our data widen the knowledge about genetic variation between Saccharomyces cerevisiae strains and can form the basis for planning future work in PGC-related strains and with PGC-derived alleles.
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Affiliation(s)
- Polina B. Drozdova
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- Bioinformatics Institute, St. Petersburg, Russia
| | - Oleg V. Tarasov
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Scientific Center of RAS, St. Petersburg, Russia
| | - Andrew G. Matveenko
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
- Laboratory of Amyloid Biology, Saint Petersburg State University, St. Petersburg, Russia
| | - Elina A. Radchenko
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- Bioinformatics Institute, St. Petersburg, Russia
| | - Julia V. Sopova
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg, Russia
| | - Dmitrii E. Polev
- Research Resource Center for Molecular and Cell Technologies, Research Park, Saint-Petersburg State University, St. Petersburg, Russia
| | - Sergey G. Inge-Vechtomov
- Dept. of Genetics and Biotechnology, Saint Petersburg State University, St. Petersburg, Russia
- St. Petersburg Branch, Vavilov Institute of General Genetics of the Russian Academy of Sciences, St. Petersburg, Russia
| | - Pavel V. Dobrynin
- Bioinformatics Institute, St. Petersburg, Russia
- Theodosius Dobzhansky Center for Genome Bioinformatics, Saint Petersburg State University, St. Petersburg, Russia
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25
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Beznosková P, Gunišová S, Valášek LS. Rules of UGA-N decoding by near-cognate tRNAs and analysis of readthrough on short uORFs in yeast. RNA (NEW YORK, N.Y.) 2016; 22:456-66. [PMID: 26759455 PMCID: PMC4748822 DOI: 10.1261/rna.054452.115] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 12/10/2015] [Indexed: 05/13/2023]
Abstract
The molecular mechanism of stop codon recognition by the release factor eRF1 in complex with eRF3 has been described in great detail; however, our understanding of what determines the difference in termination efficiencies among various stop codon tetranucleotides and how near-cognate (nc) tRNAs recode stop codons during programmed readthrough in Saccharomyces cerevisiae is still poor. Here, we show that UGA-C as the only tetranucleotide of all four possible combinations dramatically exacerbated the readthrough phenotype of the stop codon recognition-deficient mutants in eRF1. Since the same is true also for UAA-C and UAG-C, we propose that the exceptionally high readthrough levels that all three stop codons display when followed by cytosine are partially caused by the compromised sampling ability of eRF1, which specifically senses cytosine at the +4 position. The difference in termination efficiencies among the remaining three UGA-N tetranucleotides is then given by their varying preferences for nc-tRNAs. In particular, UGA-A allows increased incorporation of Trp-tRNA whereas UGA-G and UGA-C favor Cys-tRNA. Our findings thus expand the repertoire of general decoding rules by showing that the +4 base determines the preferred selection of nc-tRNAs and, in the case of cytosine, it also genetically interacts with eRF1. Finally, using an example of the GCN4 translational control governed by four short uORFs, we also show how the evolution of this mechanism dealt with undesirable readthrough on those uORFs that serve as the key translation reinitiation promoting features of the GCN4 regulation, as both of these otherwise counteracting activities, readthrough versus reinitiation, are mediated by eIF3.
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Affiliation(s)
- Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, Czech Republic Faculty of Science, Charles University in Prague, 128 43 Prague, Czech Republic
| | - Stanislava Gunišová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, Czech Republic
| | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, Czech Republic
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26
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Bulygin KN, Bartuli YS, Malygin AA, Graifer DM, Frolova LY, Karpova GG. Chemical footprinting reveals conformational changes of 18S and 28S rRNAs at different steps of translation termination on the human ribosome. RNA (NEW YORK, N.Y.) 2016; 22:278-289. [PMID: 26655225 PMCID: PMC4712677 DOI: 10.1261/rna.053801.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
Translation termination in eukaryotes is mediated by release factors: eRF1, which is responsible for stop codon recognition and peptidyl-tRNA hydrolysis, and GTPase eRF3, which stimulates peptide release. Here, we have utilized ribose-specific probes to investigate accessibility of rRNA backbone in complexes formed by association of mRNA- and tRNA-bound human ribosomes with eRF1•eRF3•GMPPNP, eRF1•eRF3•GTP, or eRF1 alone as compared with complexes where the A site is vacant or occupied by tRNA. Our data show which rRNA ribose moieties are protected from attack by the probes in the complexes with release factors and reveal the rRNA regions increasing their accessibility to the probes after the factors bind. These regions in 28S rRNA are helices 43 and 44 in the GTPase associated center, the apical loop of helix 71, and helices 89, 92, and 94 as well as 18S rRNA helices 18 and 34. Additionally, the obtained data suggest that eRF3 neither interacts with the rRNA ribose-phosphate backbone nor dissociates from the complex after GTP hydrolysis. Taken together, our findings provide new information on architecture of the eRF1 binding site on mammalian ribosome at various translation termination steps and on conformational rearrangements induced by binding of the release factors.
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MESH Headings
- Binding Sites
- Codon, Terminator
- Escherichia coli/genetics
- Escherichia coli/metabolism
- Female
- Guanosine Triphosphate/metabolism
- Humans
- Hydrolysis
- Nucleic Acid Conformation
- Peptide Chain Termination, Translational
- Peptide Termination Factors/genetics
- Peptide Termination Factors/metabolism
- Placenta/chemistry
- Pregnancy
- Protein Binding
- RNA, Messenger/chemistry
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Ribosomal, 18S/chemistry
- RNA, Ribosomal, 18S/genetics
- RNA, Ribosomal, 18S/metabolism
- RNA, Ribosomal, 28S/chemistry
- RNA, Ribosomal, 28S/genetics
- RNA, Ribosomal, 28S/metabolism
- RNA, Transfer, Amino Acyl/chemistry
- RNA, Transfer, Amino Acyl/genetics
- RNA, Transfer, Amino Acyl/metabolism
- Ribosomes/genetics
- Ribosomes/metabolism
- Saccharomyces cerevisiae/genetics
- Saccharomyces cerevisiae/metabolism
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Affiliation(s)
- Konstantin N Bulygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Yulia S Bartuli
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Alexey A Malygin
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia Novosibirsk State University, Novosibirsk 630090, Russia
| | - Dmitri M Graifer
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia Novosibirsk State University, Novosibirsk 630090, Russia
| | - Ludmila Yu Frolova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Galina G Karpova
- Institute of Chemical Biology and Fundamental Medicine, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia Novosibirsk State University, Novosibirsk 630090, Russia
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27
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Pillay S, Li Y, Wong LE, Pervushin K. Structural characterization of eRF1 mutants indicate a complex mechanism of stop codon recognition. Sci Rep 2016; 6:18644. [PMID: 26725946 PMCID: PMC4698671 DOI: 10.1038/srep18644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 11/17/2015] [Indexed: 12/19/2022] Open
Abstract
Eukarya translation termination requires the stop codon recognizing protein eRF1. In contrast to the multiple proteins required for translation termination in Bacteria, eRF1 retains the ability to recognize all three of the stop codons. The details of the mechanism that eRF1 uses to recognize stop codons has remained elusive. This study describes the structural effects of mutations in the eRF1 N-domain that have previously been shown to alter stop codon recognition specificity. Here, we propose a model of eRF1 binding to the pre-translation termination ribosomal complex that is based in part on our solution NMR structures of the wild-type and mutant eRF1 N-domains. Since structural perturbations induced by these mutations were spread throughout the protein structure, residual dipolar coupling (RDC) data were recorded to establish the long-range effects of the specific mutations, E55Q, Y125F, Q(122)FM(Y)F(126). RDCs were recorded on (15)N-labeled eRF1 N-domain weakly aligned in either 5% w/v n-octyl-penta (ethylene glycol)/octanol (C8E5) or the filamentous phage Pf1. These data indicate that the mutations alter the conformation and dynamics of the GTS loop that is distant from the mutation sites. We propose that the GTS loop forms a switch that is key for the multiple codon recognition capability of eRF1.
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Affiliation(s)
- Shubhadra Pillay
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Yan Li
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Leo E Wong
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Konstantin Pervushin
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
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28
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Bezerra AR, Guimarães AR, Santos MAS. Non-Standard Genetic Codes Define New Concepts for Protein Engineering. Life (Basel) 2015; 5:1610-28. [PMID: 26569314 PMCID: PMC4695839 DOI: 10.3390/life5041610] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 10/12/2015] [Accepted: 10/21/2015] [Indexed: 11/16/2022] Open
Abstract
The essential feature of the genetic code is the strict one-to-one correspondence between codons and amino acids. The canonical code consists of three stop codons and 61 sense codons that encode 20% of the amino acid repertoire observed in nature. It was originally designated as immutable and universal due to its conservation in most organisms, but sequencing of genes from the human mitochondrial genomes revealed deviations in codon assignments. Since then, alternative codes have been reported in both nuclear and mitochondrial genomes and genetic code engineering has become an important research field. Here, we review the most recent concepts arising from the study of natural non-standard genetic codes with special emphasis on codon re-assignment strategies that are relevant to engineering genetic code in the laboratory. Recent tools for synthetic biology and current attempts to engineer new codes for incorporation of non-standard amino acids are also reviewed in this article.
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Affiliation(s)
- Ana R Bezerra
- Health Sciences Department, Institute for Biomedicine-iBiMED, University of Aveiro, Campus de Santiago, Aveiro 3810-193, Portugal.
| | - Ana R Guimarães
- Health Sciences Department, Institute for Biomedicine-iBiMED, University of Aveiro, Campus de Santiago, Aveiro 3810-193, Portugal.
| | - Manuel A S Santos
- Health Sciences Department, Institute for Biomedicine-iBiMED, University of Aveiro, Campus de Santiago, Aveiro 3810-193, Portugal.
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29
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Matheisl S, Berninghausen O, Becker T, Beckmann R. Structure of a human translation termination complex. Nucleic Acids Res 2015; 43:8615-26. [PMID: 26384426 PMCID: PMC4605324 DOI: 10.1093/nar/gkv909] [Citation(s) in RCA: 93] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 08/12/2015] [Indexed: 12/02/2022] Open
Abstract
In contrast to bacteria that have two release factors, RF1 and RF2, eukaryotes only possess one unrelated release factor eRF1, which recognizes all three stop codons of the mRNA and hydrolyses the peptidyl-tRNA bond. While the molecular basis for bacterial termination has been elucidated, high-resolution structures of eukaryotic termination complexes have been lacking. Here we present a 3.8 Å structure of a human translation termination complex with eRF1 decoding a UAA(A) stop codon. The complex was formed using the human cytomegalovirus (hCMV) stalling peptide, which perturbs the peptidyltransferase center (PTC) to silence the hydrolysis activity of eRF1. Moreover, unlike sense codons or bacterial stop codons, the UAA stop codon adopts a U-turn-like conformation within a pocket formed by eRF1 and the ribosome. Inducing the U-turn conformation for stop codon recognition rationalizes how decoding by eRF1 includes monitoring geometry in order to discriminate against sense codons.
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Affiliation(s)
- Sarah Matheisl
- Gene Center and Center for integrated Protein Science Munich, Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Otto Berninghausen
- Gene Center and Center for integrated Protein Science Munich, Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Thomas Becker
- Gene Center and Center for integrated Protein Science Munich, Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
| | - Roland Beckmann
- Gene Center and Center for integrated Protein Science Munich, Department of Biochemistry, Feodor-Lynen-Str. 25, University of Munich, 81377 Munich, Germany
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30
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Chai B, Li C, Yu J, Hao Y, Guo P, Shen Q. Stop codon recognition in the early-diverged protozoans Giardia lamblia and Trichomonas vaginalis. Mol Biochem Parasitol 2015; 202:15-21. [PMID: 26310515 DOI: 10.1016/j.molbiopara.2015.08.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 06/25/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
Two classes of polypeptide release factors (RFs) are responsible for maintaining accuracy in translation termination; however, their detailed mechanism of action and evolutionary history of these factors remain elusive. The structure and function of RFs vary in bacteria and eukaryotes, a fact that is suggestive of evolutionary changes in the translation termination system. Giardia lamblia (Diplomonada) and Trichomonas vaginalis (Parabasalia) are considered as early-diverged eukaryotes. The class II release factor, eRF3, of Giardia (Gl-eRF3) appears to have only one domain that corresponds to EF-1α and lacks the N-terminal domain, similar to that of eRF3 of other organisms. In the present study, we show that the chimeric molecules Gl/Sc eRF1 and Tv/Sc eRF1, which are composed of the N-terminal domain of Gl-eRF1 or Tv-eRF1, fused to the core domain (M and C domain) of Saccharomyces cerevisiae eRF1 (Sc-eRF1), resulting in loss of the RF properties of the N-terminal domain. This suggests that the conformation of eRF1 for stop codon recognition in Giardia and Trichomonas varies from the eRF1s of other eukaryotes, including ciliates and yeast. Further studies using intra-N-terminal chimeras of eRF1 indicated that the combination of the GTS loop and NIKS motif from Gl-eRF1 and the Y-C-F motif from Sc-eRF1within the N terminal domain of hybrid eRF1 could restore UGA, but not UAG and UGA recognition. In contrast, the combination of the GTS loop and the NIKS motif of Sc-eRF1 and the Y-C-F motif of Gl-eRF1 could restore UAG and UAA recognition, but not UGA recognition. Thus, these results confirm the findings of previous studies that three motifs in eRF1 are necessary for discrimination of the three bases of stop codons. The NIKS motif is responsible for recognition of the first two bases of UAA and UAG, and the Y-C-F motif identifies the second base of UGA by Gl-eRF1. Amino acid residue substitutions in Gl/Sc-eRF1 by corresponding residues of Sc-eRF1 could change and even restore RF activity, further suggesting different conformation of eRF1 are used for stop codon recognition in Giardia and in Saccharomyces.
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Affiliation(s)
- Baofeng Chai
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China.
| | - Cui Li
- Faculty of Environment and Economics, Shanxi University of Finance and Economics, Taiyuan 030006, China
| | - Jingfei Yu
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Yanrong Hao
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Ping Guo
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
| | - Quan Shen
- Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
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31
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Saito K, Ito K. Genetic analysis of L123 of the tRNA-mimicking eukaryote release factor eRF1, an amino acid residue critical for discrimination of stop codons. Nucleic Acids Res 2015; 43:4591-601. [PMID: 25897120 PMCID: PMC4482090 DOI: 10.1093/nar/gkv376] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/09/2015] [Indexed: 11/18/2022] Open
Abstract
In eukaryotes, the tRNA-mimicking polypeptide-chain release factor, eRF1, decodes stop codons on the ribosome in a complex with eRF3; this complex exhibits striking structural similarity to the tRNA–eEF1A–GTP complex. Although amino acid residues or motifs of eRF1 that are critical for stop codon discrimination have been identified, the details of the molecular mechanisms involved in the function of the ribosomal decoding site remain obscure. Here, we report analyses of the position-123 amino acid of eRF1 (L123 in Saccharomyces cerevisiae eRF1), a residue that is phylogenetically conserved among species with canonical and variant genetic codes. In vivo readthrough efficiency analysis and genetic growth complementation analysis of the residue-123 systematic mutants suggested that this amino acid functions in stop codon discrimination in a manner coupled with eRF3 binding, and distinctive from previously reported adjacent residues. Furthermore, aminoglycoside antibiotic sensitivity analysis and ribosomal docking modeling of eRF1 in a quasi-A/T state suggested a functional interaction between the side chain of L123 and ribosomal residues critical for codon recognition in the decoding site, as a molecular explanation for coupling with eRF3. Our results provide insights into the molecular mechanisms underlying stop codon discrimination by a tRNA-mimicking protein on the ribosome.
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Affiliation(s)
- Kazuki Saito
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba 277-8562, Japan
| | - Koichi Ito
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba 277-8562, Japan
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32
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Blanchet S, Rowe M, Von der Haar T, Fabret C, Demais S, Howard MJ, Namy O. New insights into stop codon recognition by eRF1. Nucleic Acids Res 2015; 43:3298-308. [PMID: 25735746 PMCID: PMC4381064 DOI: 10.1093/nar/gkv154] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 02/17/2015] [Indexed: 11/25/2022] Open
Abstract
In eukaryotes, translation termination is performed by eRF1, which recognizes stop codons via its N-terminal domain. Many previous studies based on point mutagenesis, cross-linking experiments or eRF1 chimeras have investigated the mechanism by which the stop signal is decoded by eRF1. Conserved motifs, such as GTS and YxCxxxF, were found to be important for termination efficiency, but the recognition mechanism remains unclear. We characterized a region of the eRF1 N-terminal domain, the P1 pocket, that we had previously shown to be involved in termination efficiency. We performed alanine scanning mutagenesis of this region, and we quantified in vivo readthrough efficiency for each alanine mutant. We identified two residues, arginine 65 and lysine 109, as critical for recognition of the three stop codons. We also demonstrated a role for the serine 33 and serine 70 residues in UGA decoding in vivo. NMR analysis of the alanine mutants revealed that the correct conformation of this region was controlled by the YxCxxxF motif. By combining our genetic data with a structural analysis of eRF1 mutants, we were able to formulate a new model in which the stop codon interacts with eRF1 through the P1 pocket.
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Affiliation(s)
- Sandra Blanchet
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Batiment 400, 91400 Orsay, France
| | - Michelle Rowe
- School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK
| | | | - Céline Fabret
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Batiment 400, 91400 Orsay, France
| | - Stéphane Demais
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Batiment 400, 91400 Orsay, France
| | - Mark J Howard
- School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK
| | - Olivier Namy
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Batiment 400, 91400 Orsay, France
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33
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Zhuang Q, Feng T, Coleman ML. Modifying the maker: Oxygenases target ribosome biology. ACTA ACUST UNITED AC 2015; 3:e1009331. [PMID: 26779412 PMCID: PMC4682802 DOI: 10.1080/21690731.2015.1009331] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/14/2014] [Accepted: 01/15/2014] [Indexed: 01/05/2023]
Abstract
The complexity of the eukaryotic protein synthesis machinery is partly driven by extensive and diverse modifications to associated proteins and RNAs. These modifications can have important roles in regulating translation factor activity and ribosome biogenesis and function. Further investigation of ‘translational modifications’ is warranted considering the growing evidence implicating protein synthesis as a critical point of gene expression control that is commonly deregulated in disease. New evidence suggests that translation is a major new target for oxidative modifications, specifically hydroxylations and demethylations, which generally are catalyzed by a family of emerging oxygenase enzymes that act at the interface of nutrient availability and metabolism. This review summarizes what is currently known about the role or these enzymes in targeting rRNA synthesis, protein translation and associated cellular processes.
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Affiliation(s)
- Qinqin Zhuang
- Tumour Oxygenase Group; School of Cancer Sciences ; University of Birmingham ; Birmingham, UK
| | - Tianshu Feng
- Centre for Cellular and Molecular Physiology; University of Oxford ; Oxford, UK
| | - Mathew L Coleman
- Tumour Oxygenase Group; School of Cancer Sciences ; University of Birmingham ; Birmingham, UK
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34
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Blanchet S, Cornu D, Argentini M, Namy O. New insights into the incorporation of natural suppressor tRNAs at stop codons in Saccharomyces cerevisiae. Nucleic Acids Res 2014; 42:10061-72. [PMID: 25056309 PMCID: PMC4150775 DOI: 10.1093/nar/gku663] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Stop codon readthrough may be promoted by the nucleotide environment or drugs. In such cases, ribosomes incorporate a natural suppressor tRNA at the stop codon, leading to the continuation of translation in the same reading frame until the next stop codon and resulting in the expression of a protein with a new potential function. However, the identity of the natural suppressor tRNAs involved in stop codon readthrough remains unclear, precluding identification of the amino acids incorporated at the stop position. We established an in vivo reporter system for identifying the amino acids incorporated at the stop codon, by mass spectrometry in the yeast Saccharomyces cerevisiae. We found that glutamine, tyrosine and lysine were inserted at UAA and UAG codons, whereas tryptophan, cysteine and arginine were inserted at UGA codon. The 5′ nucleotide context of the stop codon had no impact on the identity or proportion of amino acids incorporated by readthrough. We also found that two different glutamine tRNAGln were used to insert glutamine at UAA and UAG codons. This work constitutes the first systematic analysis of the amino acids incorporated at stop codons, providing important new insights into the decoding rules used by the ribosome to read the genetic code.
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Affiliation(s)
- Sandra Blanchet
- Institut de Génétique et Microbiologie, Université Paris-Sud, UMR8621, 91400 Orsay, France
| | - David Cornu
- CNRS, Centre de Recherche de Gif, FRC3115, Imagif, 91198 Gif-sur-Yvette Cedex, France
| | - Manuela Argentini
- CNRS, Centre de Recherche de Gif, FRC3115, Imagif, 91198 Gif-sur-Yvette Cedex, France
| | - Olivier Namy
- Institut de Génétique et Microbiologie, Université Paris-Sud, UMR8621, 91400 Orsay, France CNRS, 91400 Orsay, France
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35
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Karijolich J, Yu YT. Therapeutic suppression of premature termination codons: mechanisms and clinical considerations (review). Int J Mol Med 2014; 34:355-62. [PMID: 24939317 PMCID: PMC4094583 DOI: 10.3892/ijmm.2014.1809] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 06/06/2014] [Indexed: 12/22/2022] Open
Abstract
An estimated one-third of genetic disorders are the result of mutations that generate premature termination codons (PTCs) within protein coding genes. These disorders are phenotypically diverse and consist of diseases that affect both young and old individuals. Various small molecules have been identified that are capable of modulating the efficiency of translation termination, including select antibiotics of the aminoglycoside family and multiple novel synthetic molecules, including PTC124. Several of these agents have proved their effectiveness at promoting nonsense suppression in preclinical animal models, as well as in clinical trials. In addition, it has recently been shown that box H/ACA RNA-guided peudouridylation, when directed to modify PTCs, can also promote nonsense suppression. In this review, we summarize our current understanding of eukaryotic translation termination and discuss various methods for promoting the read-through of disease-causing PTCs, as well as the current obstacles that stand in the way of using the discussed agents broadly in clinical practice.
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Affiliation(s)
- John Karijolich
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA
| | - Yi-Tao Yu
- Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY 14642, USA
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36
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Wada M, Ito K. A genetic approach for analyzing the co-operative function of the tRNA mimicry complex, eRF1/eRF3, in translation termination on the ribosome. Nucleic Acids Res 2014; 42:7851-66. [PMID: 24914055 PMCID: PMC4081094 DOI: 10.1093/nar/gku493] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
During termination of translation in eukaryotes, a GTP-binding protein, eRF3, functions within a complex with the tRNA-mimicking protein, eRF1, to decode stop codons. It remains unclear how the tRNA-mimicking protein co-operates with the GTPase and with the functional sites on the ribosome. In order to elucidate the molecular characteristics of tRNA-mimicking proteins involved in stop codon decoding, we have devised a heterologous genetic system in Saccharomyces cerevisiae. We found that eRF3 from Pneumocystis carinii (Pc-eRF3) did not complement depletion of S. cerevisiae eRF3. The strength of Pc-eRF3 binding to Sc-eRF1 depends on the GTP-binding domain, suggesting that defects of the GTPase switch in the heterologous complex causes the observed lethality. We isolated mutants of Pc-eRF3 and Sc-eRF1 that restore cell growth in the presence of Pc-eRF3 as the sole source of eRF3. Mapping of these mutations onto the latest 3D-complex structure revealed that they were located in the binding-interface region between eRF1 and eRF3, as well as in the ribosomal functional sites. Intriguingly, a novel functional site was revealed adjacent to the decoding site of eRF1, on the tip domain that mimics the tRNA anticodon loop. This novel domain likely participates in codon recognition, coupled with the GTPase function.
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Affiliation(s)
- Miki Wada
- Technical office, The Institute of Medical Science, The University of Tokyo, Minato-ku, Tokyo 108-8639, Japan Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba, 277-8562, Japan
| | - Koichi Ito
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa-city, Chiba, 277-8562, Japan
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37
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Liu W, Mellado L, Espeso EA, Sealy-Lewis HM. In Aspergillus nidulans the suppressors suaA and suaC code for release factors eRF1 and eRF3 and suaD codes for a glutamine tRNA. G3 (BETHESDA, MD.) 2014; 4:1047-57. [PMID: 24727290 PMCID: PMC4065248 DOI: 10.1534/g3.114.010702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/25/2014] [Indexed: 11/24/2022]
Abstract
In Aspergillus nidulans, after extensive mutagenesis, a collection of mutants was obtained and four suppressor loci were identified genetically that could suppress mutations in putative chain termination mutations in different genes. Suppressor mutations in suaB and suaD have a similar restricted spectrum of suppression and suaB111 was previously shown to be an alteration in the anticodon of a gln tRNA. We have shown that like suaB, a suaD suppressor has a mutation in the anticodon of another gln tRNA allowing suppression of UAG mutations. Mutations in suaA and suaC had a broad spectrum of suppression. Four suaA mutations result in alterations in the coding region of the eukaryotic release factor, eRF1, and another suaA mutation has a mutation in the upstream region of eRF1 that prevents splicing of the first intron within the 5'UTR. Epitope tagging of eRF1 in this mutant results in 20% of the level of eRF1 compared to the wild-type. Two mutations in suaC result in alterations in the eukaryotic release factor, eRF3. This is the first description in Aspergillus nidulans of an alteration in eRF3 leading to suppression of chain termination mutations.
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Affiliation(s)
- Wen Liu
- Department of Biological, Biomedical and Environmental Sciences, University of Hull, Hull HU6 7RX, United Kingdom
| | - Laura Mellado
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu, 9, 28040 Madrid, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu, 9, 28040 Madrid, Spain
| | - Heather M Sealy-Lewis
- Department of Biological, Biomedical and Environmental Sciences, University of Hull, Hull HU6 7RX, United Kingdom
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38
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Optimal translational termination requires C4 lysyl hydroxylation of eRF1. Mol Cell 2014; 53:645-54. [PMID: 24486019 PMCID: PMC3991326 DOI: 10.1016/j.molcel.2013.12.028] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/26/2013] [Accepted: 12/27/2013] [Indexed: 01/22/2023]
Abstract
Efficient stop codon recognition and peptidyl-tRNA hydrolysis are essential in order to terminate translational elongation and maintain protein sequence fidelity. Eukaryotic translational termination is mediated by a release factor complex that includes eukaryotic release factor 1 (eRF1) and eRF3. The N terminus of eRF1 contains highly conserved sequence motifs that couple stop codon recognition at the ribosomal A site to peptidyl-tRNA hydrolysis. We reveal that Jumonji domain-containing 4 (Jmjd4), a 2-oxoglutarate- and Fe(II)-dependent oxygenase, catalyzes carbon 4 (C4) lysyl hydroxylation of eRF1. This posttranslational modification takes place at an invariant lysine within the eRF1 NIKS motif and is required for optimal translational termination efficiency. These findings further highlight the role of 2-oxoglutarate/Fe(II) oxygenases in fundamental cellular processes and provide additional evidence that ensuring fidelity of protein translation is a major role of hydroxylation. Jmjd4 hydroxylates translational termination factor eRF1 The C4 lysyl hydroxylase activity of Jmjd4 is unprecedented in animals Hydroxylation occurs within the eRF1 stop codon recognition domain Inhibiting eRF1 K63 hydroxylation promotes stop codon readthrough
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39
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des Georges A, Hashem Y, Unbehaun A, Grassucci RA, Taylor D, Hellen CUT, Pestova TV, Frank J. Structure of the mammalian ribosomal pre-termination complex associated with eRF1.eRF3.GDPNP. Nucleic Acids Res 2013; 42:3409-18. [PMID: 24335085 PMCID: PMC3950680 DOI: 10.1093/nar/gkt1279] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Eukaryotic translation termination results from the complex functional interplay between two release factors, eRF1 and eRF3, in which GTP hydrolysis by eRF3 couples codon recognition with peptidyl-tRNA hydrolysis by eRF1. Here, we present a cryo-electron microscopy structure of pre-termination complexes associated with eRF1•eRF3•GDPNP at 9.7 -Å resolution, which corresponds to the initial pre-GTP hydrolysis stage of factor attachment and stop codon recognition. It reveals the ribosomal positions of eRFs and provides insights into the mechanisms of stop codon recognition and triggering of eRF3's GTPase activity.
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Affiliation(s)
- Amédée des Georges
- Howard Hughes Medical Institute, Chevy Chase, MD, USA, Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA, Department of Cell Biology, SUNY Downstate Medical Center, Brooklyn, NY, USA, Department of Pharmacology, Case Western Reserve University, Cleveland, OH, USA and Department of Biological Sciences, Columbia University, New York, NY, USA
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40
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Beznosková P, Cuchalová L, Wagner S, Shoemaker CJ, Gunišová S, von der Haar T, Valášek LS. Translation initiation factors eIF3 and HCR1 control translation termination and stop codon read-through in yeast cells. PLoS Genet 2013; 9:e1003962. [PMID: 24278036 PMCID: PMC3836723 DOI: 10.1371/journal.pgen.1003962] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/01/2013] [Indexed: 11/19/2022] Open
Abstract
Translation is divided into initiation, elongation, termination and ribosome recycling. Earlier work implicated several eukaryotic initiation factors (eIFs) in ribosomal recycling in vitro. Here, we uncover roles for HCR1 and eIF3 in translation termination in vivo. A substantial proportion of eIF3, HCR1 and eukaryotic release factor 3 (eRF3) but not eIF5 (a well-defined "initiation-specific" binding partner of eIF3) specifically co-sediments with 80S couples isolated from RNase-treated heavy polysomes in an eRF1-dependent manner, indicating the presence of eIF3 and HCR1 on terminating ribosomes. eIF3 and HCR1 also occur in ribosome- and RNA-free complexes with both eRFs and the recycling factor ABCE1/RLI1. Several eIF3 mutations reduce rates of stop codon read-through and genetically interact with mutant eRFs. In contrast, a slow growing deletion of hcr1 increases read-through and accumulates eRF3 in heavy polysomes in a manner suppressible by overexpressed ABCE1/RLI1. Based on these and other findings we propose that upon stop codon recognition, HCR1 promotes eRF3·GDP ejection from the post-termination complexes to allow binding of its interacting partner ABCE1/RLI1. Furthermore, the fact that high dosage of ABCE1/RLI1 fully suppresses the slow growth phenotype of hcr1Δ as well as its termination but not initiation defects implies that the termination function of HCR1 is more critical for optimal proliferation than its function in translation initiation. Based on these and other observations we suggest that the assignment of HCR1 as a bona fide eIF3 subunit should be reconsidered. Together our work characterizes novel roles of eIF3 and HCR1 in stop codon recognition, defining a communication bridge between the initiation and termination/recycling phases of translation.
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Affiliation(s)
- Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska, Prague, the Czech Republic
| | - Lucie Cuchalová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska, Prague, the Czech Republic
| | - Susan Wagner
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska, Prague, the Czech Republic
| | - Christopher J. Shoemaker
- Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
| | - Stanislava Gunišová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska, Prague, the Czech Republic
| | | | - Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, Videnska, Prague, the Czech Republic
- * E-mail:
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Xu L, Hao Y, Li C, Shen Q, Chai B, Wang W, Liang A. Identification of amino acids responsible for stop codon recognition for polypeptide chain release factor. Biochem Cell Biol 2013; 91:155-64. [PMID: 23668788 DOI: 10.1139/bcb-2012-0091] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
One factor involved in eukaryotic translation termination is class 1 release factor in eukaryotes (eRF1), which functions to decode stop codons. Variant code species, such as ciliates, frequently exhibit altered stop codon recognition. Studies revealed that some class-specific residues in the eRF1 N-terminal domain are responsible for stop codon reassignment in ciliates. Here, we investigated the effects on stop codon recognition of chimeric eRF1s containing the N-terminal domain of Euplotes octocarinatus and Blepharisma japonicum eRF1 fused to Saccharomyces cerevisiae M and C domains using dual luciferase read-through assays. Mutation of class-specific residues in different eRF1 classes was also studied to identify key residues and motifs involved in stop codon decoding. As expected, our results demonstrate that 3 pockets within the eRF1 N-terminal domain were involved in decoding stop codon nucleotides. However, allocation of residues to each pocket was revalued. Our data suggest that hydrophobic and class-specific surface residues participate in different functions: modulation of pocket conformation and interaction with stop codon nucleotides, respectively. Residues conserved across all eRF1s determine the relative orientation of the 3 pockets according to stop codon nucleotides. However, quantitative analysis of variant ciliate and yeast eRF1 point mutants did not reveal any correlation between evolutionary conservation of class-specific residues and termination-related functional specificity and was limited in elucidating a detailed mechanism for ciliate stop codon reassignment. Thus, based on isolation of suppressor tRNAs from Euplotes and Tetrahymena, we propose that stop codon reassignment in ciliates may be controlled by cooperation between eRF1 and suppressor tRNAs.
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Affiliation(s)
- Lijun Xu
- a Key Laboratory of Chemical Biology and Molecular Engineering, Ministry of Education, China; and Institute of Biotechnology, Shanxi University, Taiyuan 030006, China
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A Single Amino Acid Substitution Alters Omnipotent eRF1 of Dileptus to Euplotes-type Dualpotent eRF1: Standard Codon Usage May be Advantageous in Raptorial Ciliates. Protist 2013; 164:440-9. [DOI: 10.1016/j.protis.2013.02.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2012] [Revised: 02/19/2013] [Accepted: 02/19/2013] [Indexed: 11/23/2022]
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Kryuchkova P, Grishin A, Eliseev B, Karyagina A, Frolova L, Alkalaeva E. Two-step model of stop codon recognition by eukaryotic release factor eRF1. Nucleic Acids Res 2013; 41:4573-86. [PMID: 23435318 PMCID: PMC3632111 DOI: 10.1093/nar/gkt113] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Release factor eRF1 plays a key role in the termination of protein synthesis in eukaryotes. The eRF1 consists of three domains (N, M and C) that perform unique roles in termination. Previous studies of eRF1 point mutants and standard/variant code eRF1 chimeras unequivocally demonstrated a direct involvement of the highly conserved N-domain motifs (NIKS, YxCxxxF and GTx) in stop codon recognition. In the current study, we extend this work by investigating the role of the 41 invariant and conserved N-domain residues in stop codon decoding by human eRF1. Using a combination of the conservative and non-conservative amino acid substitutions, we measured the functional activity of >80 mutant eRF1s in an in vitro reconstituted eukaryotic translation system and selected 15 amino acid residues essential for recognition of different stop codon nucleotides. Furthermore, toe-print analyses provide evidence of a conformational rearrangement of ribosomal complexes that occurs during binding of eRF1 to messenger RNA and reflects stop codon decoding activity of eRF1. Based on our experimental data and molecular modelling of the N-domain at the ribosomal A site, we propose a two-step model of stop codon decoding in the eukaryotic ribosome.
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Affiliation(s)
- Polina Kryuchkova
- Engelhardt Institute of Molecular Biology, the Russian Academy of Sciences, 119991 Moscow, Russia
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44
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Nürenberg E, Tampé R. Tying up loose ends: ribosome recycling in eukaryotes and archaea. Trends Biochem Sci 2012; 38:64-74. [PMID: 23266104 DOI: 10.1016/j.tibs.2012.11.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 11/15/2012] [Accepted: 11/16/2012] [Indexed: 01/29/2023]
Abstract
Ribosome recycling is the final - or first - step of the cyclic process of mRNA translation. In eukaryotes and archaea, dissociation of the two ribosomal subunits proceeds in a fundamentally different way than in bacteria. It requires the ABC-type ATPase ABCE1 [previously named RNase L inhibitor (Rli)1 or host protein (HP)68], but the reaction and its regulation remain enigmatic. Here, we focus on ribosome recycling in its physiological context, including translation termination and reinitiation. The regulation of this crucial event can only be described by a systems biology approach, involving a network of proteins modulating mRNA translation. The key role of ABCE1, and what is known about the structure and function of this versatile protein, is discussed.
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Affiliation(s)
- Elina Nürenberg
- Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt/M., Germany
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Cryo-EM structure of the mammalian eukaryotic release factor eRF1-eRF3-associated termination complex. Proc Natl Acad Sci U S A 2012; 109:18413-8. [PMID: 23091004 DOI: 10.1073/pnas.1216730109] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Eukaryotic translation termination results from the complex functional interplay between two eukaryotic release factors, eRF1 and eRF3, and the ribosome, in which GTP hydrolysis by eRF3 couples codon recognition with peptidyl-tRNA hydrolysis by eRF1. Here, using cryo-electron microscopy (cryo-EM) and flexible fitting, we determined the structure of eRF1-eRF3-guanosine 5'-[β,γ-imido]triphosphate (GMPPNP)-bound ribosomal pretermination complex (pre-TC), which corresponds to the initial, pre-GTP hydrolysis stage of factor attachment. Our results show that eukaryotic translation termination involves a network of interactions between the two release factors and the ribosome. Our structure provides mechanistic insight into the coordination between GTP hydrolysis by eRF3 and subsequent peptide release by eRF1.
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Bidou L, Allamand V, Rousset JP, Namy O. Sense from nonsense: therapies for premature stop codon diseases. Trends Mol Med 2012; 18:679-88. [PMID: 23083810 DOI: 10.1016/j.molmed.2012.09.008] [Citation(s) in RCA: 133] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2012] [Revised: 09/19/2012] [Accepted: 09/21/2012] [Indexed: 02/04/2023]
Abstract
Ten percent of inherited diseases are caused by premature termination codon (PTC) mutations that lead to degradation of the mRNA template and to the production of a non-functional, truncated polypeptide. In addition, many acquired mutations in cancer introduce similar PTCs. In 1999, proof-of-concept for treating these disorders was obtained in a mouse model of muscular dystrophy, when administration of aminoglycosides restored protein translation by inducing the ribosome to bypass a PTC. Since, many studies have validated this approach, but despite the promise of PTC readthrough therapies, the mechanisms of translation termination remain to be precisely elucidated before even more progress can be made. Here, we review the molecular basis for PTC readthrough in eukaryotes and describe currently available compounds with significant therapeutic potential for treating genetic disorders and cancer.
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Jackson RJ, Hellen CUT, Pestova TV. Termination and post-termination events in eukaryotic translation. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2012; 86:45-93. [PMID: 22243581 DOI: 10.1016/b978-0-12-386497-0.00002-5] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Translation termination in eukaryotes occurs in response to a stop codon in the ribosomal A-site and requires two release factors (RFs), eRF1 and eRF3, which bind to the A-site as an eRF1/eRF3/GTP complex with eRF1 responsible for codon recognition. After GTP hydrolysis by eRF3, eRF1 triggers hydrolysis of the polypeptidyl-tRNA, releasing the completed protein product. This leaves an 80S ribosome still bound to the mRNA, with deacylated tRNA in its P-site and at least eRF1 in its A-site, which needs to be disassembled and released from the mRNA to allow further rounds of translation. The first step in recycling is dissociation of the 60S ribosomal subunit, leaving a 40S/deacylated tRNA complex bound to the mRNA. This is mediated by ABCE1, which is a somewhat unusual member of the ATP-binding cassette family of proteins with no membrane-spanning domain but two essential iron-sulfur clusters. Two distinct pathways have been identified for subsequent ejection of the deacylated tRNA followed by dissociation of the 40S subunit from the mRNA, one executed by a subset of the canonical initiation factors (which therefore starts the process of preparing the 40S subunit for the next round of translation) and the other by Ligatin or homologous proteins. However, although this is the normal sequence of events, there are exceptions where the termination reaction is followed by reinitiation on the same mRNA (usually) at a site downstream of the stop codon. The overwhelming majority of such reinitiation events occur when the 5'-proximal open reading frame (ORF) is short and can result in significant regulation of translation of the protein-coding ORF, but there are also rare examples, mainly bicistronic viral RNAs, of reinitiation after a long ORF. Here, we review our current understanding of the mechanisms of termination, ribosome recycling, and reinitiation after translation of short and long ORFs.
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Affiliation(s)
- Richard J Jackson
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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Conard SE, Buckley J, Dang M, Bedwell GJ, Carter RL, Khass M, Bedwell DM. Identification of eRF1 residues that play critical and complementary roles in stop codon recognition. RNA (NEW YORK, N.Y.) 2012; 18:1210-21. [PMID: 22543865 PMCID: PMC3358643 DOI: 10.1261/rna.031997.111] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 03/15/2012] [Indexed: 05/31/2023]
Abstract
The initiation and elongation stages of translation are directed by codon-anticodon interactions. In contrast, a release factor protein mediates stop codon recognition prior to polypeptide chain release. Previous studies have identified specific regions of eukaryotic release factor one (eRF1) that are important for decoding each stop codon. The cavity model for eukaryotic stop codon recognition suggests that three binding pockets/cavities located on the surface of eRF1's domain one are key elements in stop codon recognition. Thus, the model predicts that amino acid changes in or near these cavities should influence termination in a stop codon-dependent manner. Previous studies have suggested that the TASNIKS and YCF motifs within eRF1 domain one play important roles in stop codon recognition. These motifs are highly conserved in standard code organisms that use UAA, UAG, and UGA as stop codons, but are more divergent in variant code organisms that have reassigned a subset of stop codons to sense codons. In the current study, we separately introduced TASNIKS and YCF motifs from six variant code organisms into eRF1 of Saccharomyces cerevisiae to determine their effect on stop codon recognition in vivo. We also examined the consequences of additional changes at residues located between the TASNIKS and YCF motifs. Overall, our results indicate that changes near cavities two and three frequently mediated significant effects on stop codon selectivity. In particular, changes in the YCF motif, rather than the TASNIKS motif, correlated most consistently with variant code stop codon selectivity.
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Affiliation(s)
- Sara E. Conard
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Jessica Buckley
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Mai Dang
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Gregory J. Bedwell
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Richard L. Carter
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - Mohamed Khass
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
| | - David M. Bedwell
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294, USA
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Polshakov VI, Eliseev BD, Birdsall B, Frolova LY. Structure and dynamics in solution of the stop codon decoding N-terminal domain of the human polypeptide chain release factor eRF1. Protein Sci 2012; 21:896-903. [PMID: 22517631 DOI: 10.1002/pro.2067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Revised: 03/15/2012] [Accepted: 03/17/2012] [Indexed: 11/07/2022]
Abstract
The high-resolution NMR structure of the N-domain of human eRF1, responsible for stop codon recognition, has been determined in solution. The overall fold of the protein is the same as that found in the crystal structure. However, the structures of several loops, including those participating in stop codon decoding, are different. Analysis of the NMR relaxation data reveals that most of the regions with the highest structural discrepancy between the solution and solid states undergo internal motions on the ps-ns and ms time scales. The NMR data show that the N-domain of human eRF1 exists in two conformational states. The distribution of the residues having the largest chemical shift differences between the two forms indicates that helices α2 and α3, with the NIKS loop between them, can switch their orientation relative to the β-core of the protein. Such structural plasticity may be essential for stop codon recognition by human eRF1.
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Affiliation(s)
- Vladimir I Polshakov
- Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, MV Lomonosov Moscow State University, Moscow, Russia.
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