1
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Zhang Z, Khanal N, Dykstra AB, Daris K. Stop-Codon Readthrough in Therapeutic Protein Candidates Expressed from Mammalian Cells. J Pharm Sci 2024; 113:1498-1505. [PMID: 38342339 DOI: 10.1016/j.xphs.2024.02.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/03/2024] [Accepted: 02/04/2024] [Indexed: 02/13/2024]
Abstract
Stop codon readthroughs were examined in 48 recombinant therapeutic protein candidates produced from multiple clones of Chinese hamster ovary cells, using peptide mapping with LC-MS/MS detection. We found that stop codon readthrough is a common phenomenon occurring in most of these candidates, with levels varying from below the detection limit of ∼0.001 % to ∼1 %. The readthrough propensity depends on the stop codon being used, as well as the nucleotides surrounding it. The amino acids misincorporated into the stop position can be well-predicted by a third-base wobble mismatch and a first-base U/G mismatch during codon recognition, i.e., tyrosine or glutamine insertion for the UAA and UAG stop codons, and tryptophan, cysteine or arginine insertion for the UGA stop codon. Data shown in this report demonstrate the importance of optimizing the DNA sequence near the stop codon, and the importance of detecting stop codon readthroughs during the development of a therapeutic product.
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Affiliation(s)
- Zhongqi Zhang
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA.
| | - Neelam Khanal
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA
| | | | - Kristi Daris
- Process Development, Amgen Inc. Thousand Oaks, CA 91320, USA
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2
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Girardo B, Schopfer LM, Yue Y, Lockridge O, Larson MA. Polyaminated, acetylated and stop codon readthrough of recombinant Francisella tularensis universal stress protein in Escherichia coli. PLoS One 2024; 19:e0299701. [PMID: 38683788 PMCID: PMC11057771 DOI: 10.1371/journal.pone.0299701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 02/14/2024] [Indexed: 05/02/2024] Open
Abstract
Recombinant Francisella tularensis universal stress protein with a C-terminal histidine-tag (rUsp/His6) was expressed in Escherichia coli. Endogenous F. tularensis Usp has a predicted molecular mass of 30 kDa, but rUsp/His6 had an apparent molecular weight of 33 kDa based on Western blot analyses. To determine the source of the higher molecular weight for rUsp/His6, post translational modifications were examined. Tryptic peptides of purified rUsp/His6 were subjected to liquid chromatography tandem mass spectrometry (LC-MS/MS) and fragmentation spectra were searched for acetylated lysines and polyaminated glutamines. Of the 24 lysines in rUsp/His6, 10 were acetylated (K63, K68, K72, K129, K175, K201, K208, K212, K233, and K238) and three of the four glutamines had putrescine, spermidine and spermine adducts (Q55, Q60 and Q267). The level of post-translational modification was substoichiometric, eliminating the possibility that these modifications were the sole contributor to the 3 kDa extra mass of rUsp/His6. LC-MS/MS revealed that stop codon readthrough had occurred resulting in the unexpected addition of 20 extra amino acids at the C-terminus of rUsp/His6, after the histidine tag. Further, the finding of polyaminated glutamines in rUsp/His6 indicated that E. coli is capable of transglutaminase activity.
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Affiliation(s)
- Benjamin Girardo
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Lawrence M. Schopfer
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Yinshi Yue
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Oksana Lockridge
- Eppley Institute, University of Nebraska Medical Center, Omaha, NE, United States of America
| | - Marilynn A. Larson
- Pathology and Microbiology Department, University of Nebraska Medical Center, Omaha, NE, United States of America
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3
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Afonin DA, Gerasimov ES, Škodová-Sveráková I, Záhonová K, Gahura O, Albanaz ATS, Myšková E, Bykova A, Paris Z, Lukeš J, Opperdoes FR, Horváth A, Zimmer SL, Yurchenko V. Blastocrithidia nonstop mitochondrial genome and its expression are remarkably insulated from nuclear codon reassignment. Nucleic Acids Res 2024; 52:3870-3885. [PMID: 38452217 DOI: 10.1093/nar/gkae168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 02/20/2024] [Accepted: 02/27/2024] [Indexed: 03/09/2024] Open
Abstract
The canonical stop codons of the nuclear genome of the trypanosomatid Blastocrithidia nonstop are recoded. Here, we investigated the effect of this recoding on the mitochondrial genome and gene expression. Trypanosomatids possess a single mitochondrion and protein-coding transcripts of this genome require RNA editing in order to generate open reading frames of many transcripts encoded as 'cryptogenes'. Small RNAs that can number in the hundreds direct editing and produce a mitochondrial transcriptome of unusual complexity. We find B. nonstop to have a typical trypanosomatid mitochondrial genetic code, which presumably requires the mitochondrion to disable utilization of the two nucleus-encoded suppressor tRNAs, which appear to be imported into the organelle. Alterations of the protein factors responsible for mRNA editing were also documented, but they have likely originated from sources other than B. nonstop nuclear genome recoding. The population of guide RNAs directing editing is minimal, yet virtually all genes for the plethora of known editing factors are still present. Most intriguingly, despite lacking complex I cryptogene guide RNAs, these cryptogene transcripts are stochastically edited to high levels.
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MESH Headings
- Genome, Mitochondrial
- RNA Editing
- Cell Nucleus/genetics
- Cell Nucleus/metabolism
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Open Reading Frames/genetics
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Trypanosomatina/genetics
- Trypanosomatina/metabolism
- Codon/genetics
- Mitochondria/genetics
- Mitochondria/metabolism
- Codon, Terminator/genetics
- RNA, Guide, Kinetoplastida/genetics
- RNA, Guide, Kinetoplastida/metabolism
- Genetic Code
- Protozoan Proteins/genetics
- Protozoan Proteins/metabolism
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Affiliation(s)
- Dmitry A Afonin
- Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Evgeny S Gerasimov
- Faculty of Biology, Lomonosov Moscow State University, Moscow 119991, Russia
- Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow 127051, Russia
| | - Ingrid Škodová-Sveráková
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
| | - Kristína Záhonová
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV 252 50 Vestec, Czechia
- Division of Infectious Diseases, Department of Medicine, University of Alberta, T6G 2R3 Edmonton, Alberta, Canada
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
| | - Amanda T S Albanaz
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia
| | - Eva Myšková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
| | - Anastassia Bykova
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia
| | - Zdeněk Paris
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czechia
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, 370 05 České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, 370 05 České Budějovice, Czechia
| | - Fred R Opperdoes
- De Duve Institute, Université Catholique de Louvain, 1200 Brussels, Belgium
| | - Anton Horváth
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia
| | - Sara L Zimmer
- University of Minnesota Medical School, Duluth Campus, Duluth, MN 55812, USA
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czechia
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4
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Manjunath LE, Singh A, Devi Kumar S, Vasu K, Kar D, Sellamuthu K, Eswarappa SM. Transcript-specific induction of stop codon readthrough using a CRISPR-dCas13 system. EMBO Rep 2024; 25:2118-2143. [PMID: 38499809 PMCID: PMC11015002 DOI: 10.1038/s44319-024-00115-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 02/23/2024] [Accepted: 02/28/2024] [Indexed: 03/20/2024] Open
Abstract
Stop codon readthrough (SCR) is the process where translation continues beyond a stop codon on an mRNA. Here, we describe a strategy to enhance or induce SCR in a transcript-selective manner using a CRISPR-dCas13 system. Using specific guide RNAs, we target dCas13 to the region downstream of canonical stop codons of mammalian AGO1 and VEGFA mRNAs, known to exhibit natural SCR. Readthrough assays reveal enhanced SCR of these mRNAs (both exogenous and endogenous) caused by the dCas13-gRNA complexes. This effect is associated with ribosomal pausing, which has been reported for several SCR events. Our data show that CRISPR-dCas13 can also induce SCR across premature termination codons (PTCs) in the mRNAs of green fluorescent protein and TP53. We demonstrate the utility of this strategy in the induction of readthrough across the thalassemia-causing PTC in HBB mRNA and hereditary spherocytosis-causing PTC in SPTA1 mRNA. Thus, CRISPR-dCas13 can be programmed to enhance or induce SCR in a transcript-selective and stop codon-specific manner.
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Affiliation(s)
- Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
- Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Sangeetha Devi Kumar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Debaleena Kar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Karthi Sellamuthu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
- University of Texas Medical Branch, Galveston, TX, USA
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, 560012, India.
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Hikage R, Sekiya Y, Sawasato K, Nishiyama KI. CdsA, a CDP-diacylglycerol synthase involved in phospholipid and glycolipid MPIase biosynthesis, possesses multiple initiation codons. Genes Cells 2024; 29:347-355. [PMID: 38351722 DOI: 10.1111/gtc.13104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 01/25/2024] [Accepted: 02/01/2024] [Indexed: 04/04/2024]
Abstract
CdsA is a CDP-diacylglycerol synthase essential for phospholipid and glycolipid MPIase biosynthesis, and therefore for growth. The initiation codon of CdsA has been assigned as "TTG," while methionine at the 37th codon was reported to be an initiation codon in the original report. Since a vector containing the open reading frame starting with "TTG" under a controllable promoter complemented the cdsA knockout, "TTG" could function as an initiation codon. However, no evidence supporting that this "TTG" is the sole initiation codon has been reported. We determined the initiation codon by examining the ability of mutants around the N-terminal region to complement cdsA mutants. Even if the "TTG" was substituted with a stop codon, the clear complementation was observed. Moreover, the clones with multiple mutations of stop codons complemented the cdsA mutant up to the 37th codon, indicating that cdsA possesses multiple codons that can function as initiation codons. We constructed an experimental system in which the chromosomal expression of cdsA can be analyzed. By means of this system, we found that the cdsA mutant with substitution of "TTG" with a stop codon is fully functional. Thus, we concluded that CdsA contains multiple initiation codons.
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Affiliation(s)
- Runa Hikage
- Department of Applied Biological Chemistry, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Yusei Sekiya
- Department of Applied Biological Chemistry, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Katsuhiro Sawasato
- Department of Applied Biological Chemistry, Faculty of Agriculture, Iwate University, Morioka, Japan
| | - Ken-Ichi Nishiyama
- Department of Applied Biological Chemistry, Faculty of Agriculture, Iwate University, Morioka, Japan
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6
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Gemmati D, D’Aversa E, Antonica B, Grisafi M, Salvatori F, Pizzicotti S, Pellegatti P, Ciccone M, Moratelli S, Serino ML, Tisato V. Gene Dosage of F5 c.3481C>T Stop-Codon (p.R1161Ter) Switches the Clinical Phenotype from Severe Thrombosis to Recurrent Haemorrhage: Novel Hypotheses for Readthrough Strategy. Genes (Basel) 2024; 15:432. [PMID: 38674367 PMCID: PMC11050146 DOI: 10.3390/genes15040432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/28/2024] Open
Abstract
Inherited defects in the genes of blood coagulation essentially express the severity of the clinical phenotype that is directly correlated to the number of mutated alleles of the candidate leader gene (e.g., heterozygote vs. homozygote) and of possible additional coinherited traits. The F5 gene, which codes for coagulation factor V (FV), plays a two-faced role in the coagulation cascade, exhibiting both procoagulant and anticoagulant functions. Thus, defects in this gene can be predisposed to either bleeding or thrombosis. A Sanger sequence analysis detected a premature stop-codon in exon 13 of the F5 gene (c.3481C>T; p.R1161Ter) in several members of a family characterised by low circulating FV levels and contrasting clinical phenotypes. The propositus, a 29 y.o. male affected by recurrent haemorrhages, was homozygous for the F5 stop-codon and for the F5 c.1691G>A (p.R506Q; FV-Leiden) inherited from the heterozygous parents, which is suggestive of combined cis-segregation. The homozygous condition of the stop-codon completely abolished the F5 gene expression in the propositus (FV:Ag < 1%; FV:C < 1%; assessed by ELISA and PT-based one-stage clotting assay respectively), removing, in turn, any chance for FV-Leiden to act as a prothrombotic molecule. His father (57 y.o.), characterised by severe recurrent venous thromboses, underwent a complete molecular thrombophilic screening, revealing a heterozygous F2 G20210A defect, while his mother (56 y.o.), who was negative for further common coagulation defects, reported fully asymptomatic anamnesis. To dissect these conflicting phenotypes, we performed the ProC®Global (Siemens Helthineers) coagulation test aimed at assessing the global pro- and anticoagulant balance of each family member, investigating the responses to the activated protein C (APC) by means of an APC-sensitivity ratio (APC-sr). The propositus had an unexpectedly poor response to APC (APC-sr: 1.09; n.v. > 2.25), and his father and mother had an APC-sr of 1.5 and 2.0, respectively. Although ProC®Global prevalently detects the anticoagulant side of FV, the exceptionally low APC-sr of the propositus and his discordant severe-moderate haemorrhagic phenotype could suggest a residual expression of mutated FV p.506QQ through a natural readthrough or possible alternative splicing mechanisms. The coagulation pathway may be physiologically rebalanced through natural and induced strategies, and the described insights might be able to track the design of novel treatment approaches and rebalancing molecules.
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Affiliation(s)
- Donato Gemmati
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
- University Strategic Centre for Studies on Gender Medicine, University of Ferrara, 44121 Ferrara, Italy
- Centre Haemostasis & Thrombosis, University of Ferrara, 44121 Ferrara, Italy
| | - Elisabetta D’Aversa
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Bianca Antonica
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Miriana Grisafi
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | - Francesca Salvatori
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
| | | | | | - Maria Ciccone
- Haematology Unit, Hospital-University of Ferrara, 44121 Ferrara, Italy
| | - Stefano Moratelli
- Centre Haemostasis & Thrombosis, University of Ferrara, 44121 Ferrara, Italy
| | - Maria Luisa Serino
- Centre Haemostasis & Thrombosis, University of Ferrara, 44121 Ferrara, Italy
| | - Veronica Tisato
- Department of Translational Medicine, University of Ferrara, 44121 Ferrara, Italy
- University Strategic Centre for Studies on Gender Medicine, University of Ferrara, 44121 Ferrara, Italy
- Laboratory of Technology for Advanced Therapies (LTTA) Centre, University of Ferrara, 44121 Ferrara, Italy
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7
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Hinnu M, Putrinš M, Kogermann K, Kaldalu N, Tenson T. Fluorescent reporters give new insights into antibiotics-induced nonsense and frameshift mistranslation. Sci Rep 2024; 14:6883. [PMID: 38519558 PMCID: PMC10959953 DOI: 10.1038/s41598-024-57597-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/20/2024] [Indexed: 03/25/2024] Open
Abstract
We developed a reporter system based on simultaneous expression of two fluorescent proteins: GFP as a reporter of the capacity of protein synthesis and mutated mScarlet-I as a reporter of translational errors. Because of the unique stop codons or frameshift mutations introduced into the mScarlet-I gene, red fluorescence was produced only after a mistranslation event. These reporters allowed us to estimate mistranslation at a single cell level using either flow cytometry or fluorescence microscopy. We found that laboratory strains of Escherichia coli are more prone to mistranslation compared to the clinical isolates. As relevant for uropathogenic E. coli, growth in human urine elevated translational frameshifting compared to standard laboratory media, whereas different standard media had a small effect on translational fidelity. Antibiotic-induced mistranslation was studied by using amikacin (aminoglycoside family) and azithromycin (macrolide family). Bactericidal amikacin induced preferably stop-codon readthrough at a moderate level. Bacteriostatic azithromycin on the other hand induced both frameshifting and stop-codon readthrough at much higher level. Single cell analysis revealed that fluorescent reporter-protein signal can be lost due to leakage from a fraction of bacteria in the presence of antibiotics, demonstrating the complexity of the antimicrobial activity.
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Affiliation(s)
- Mariliis Hinnu
- Institute of Technology, University of Tartu, 50411, Tartu, Estonia.
| | - Marta Putrinš
- Institute of Technology, University of Tartu, 50411, Tartu, Estonia
- Institute of Pharmacy, University of Tartu, 50411, Tartu, Estonia
| | - Karin Kogermann
- Institute of Pharmacy, University of Tartu, 50411, Tartu, Estonia
| | - Niilo Kaldalu
- Institute of Technology, University of Tartu, 50411, Tartu, Estonia
| | - Tanel Tenson
- Institute of Technology, University of Tartu, 50411, Tartu, Estonia
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8
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Mangkalaphiban K, Fu L, Du M, Thrasher K, Keeling KM, Bedwell DM, Jacobson A. Extended stop codon context predicts nonsense codon readthrough efficiency in human cells. Nat Commun 2024; 15:2486. [PMID: 38509072 PMCID: PMC10954755 DOI: 10.1038/s41467-024-46703-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/06/2024] [Indexed: 03/22/2024] Open
Abstract
Protein synthesis terminates when a stop codon enters the ribosome's A-site. Although termination is efficient, stop codon readthrough can occur when a near-cognate tRNA outcompetes release factors during decoding. Seeking to understand readthrough regulation we used a machine learning approach to analyze readthrough efficiency data from published HEK293T ribosome profiling experiments and compared it to comparable yeast experiments. We obtained evidence for the conservation of identities of the stop codon, its context, and 3'-UTR length (when termination is compromised), but not the P-site codon, suggesting a P-site tRNA role in readthrough regulation. Models trained on data from cells treated with the readthrough-promoting drug, G418, accurately predicted readthrough of premature termination codons arising from CFTR nonsense alleles that cause cystic fibrosis. This predictive ability has the potential to aid development of nonsense suppression therapies by predicting a patient's likelihood of improvement in response to drugs given their nonsense mutation sequence context.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
- Department of Genomics and Computational Biology, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA
| | - Lianwu Fu
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Ming Du
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kari Thrasher
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Kim M Keeling
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - David M Bedwell
- Department of Biochemistry and Molecular Genetics, Heersink School of Medicine, The University of Alabama at Birmingham, 845 19th Street South, Birmingham, AL, 35294, USA
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, UMass Chan Medical School, 368 Plantation Street, Worcester, MA, 01655, USA.
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9
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Clark ZS, O'Connor M. Suppressor analysis links trans-translation and ribosomal protein uS7 to RluD function in Escherichia coli. Biochem Biophys Res Commun 2024; 700:149584. [PMID: 38295647 PMCID: PMC10878134 DOI: 10.1016/j.bbrc.2024.149584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 01/25/2024] [Indexed: 02/17/2024]
Abstract
The pseudouridine (ψ) synthase, RluD is responsible for three ψ modifications in the helix 69 (H69) of bacterial 23S rRNA. While normally dispensable, rluD becomes critical for rapid cell growth in bacteria that are defective in translation-termination. In slow-growing rluD- bacteria, suppressors affecting termination factors RF2 and RF3 arise frequently and restore normal termination and rapid cell growth. Here we describe two weaker suppressors, affecting rpsG, encoding ribosomal protein uS7 and ssrA, encoding tmRNA. In K-12 strains of E. coli, rpsG terminates at a TGA codon. In the suppressor strain, alteration of an upstream CAG to a TAG stop codon results in a shortened uS7 and partial alleviation of slow growth, likely by replacing an inefficient TGA stop codon with the more efficient TAG. Inefficient termination events, such as occurs in some rluD- strains, are targeted by trans-translation. Inactivation of the ssrA gene in slow-growing, termination-defective mutants lacking RluD and RF3, also partially restores robust growth, most probably by preventing destruction of completed polypeptides on ribosomes at slow-terminating stop codons. Finally, an additional role for RluD has been proposed, independent of its pseudouridine synthase activity. This is based on the observation that plasmids expressing catalytically dead (D139N or D139T) RluD proteins could nonetheless restore robust growth to an E. coli K-12 rluD- mutant. However, newly constructed D139N and D139T rluD plasmids do not have any growth-restoring activity and the original observations were likely due to the appearance of suppressors.
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Affiliation(s)
- Zachary S Clark
- Division of Biology and Biomedical Systems, School of Science and Engineering, 306 Spencer Hall, University of Missouri-Kansas City, 5007 Rockhill Rd., Kansas City, MO, 64110, USA
| | - Michael O'Connor
- Division of Biology and Biomedical Systems, School of Science and Engineering, 306 Spencer Hall, University of Missouri-Kansas City, 5007 Rockhill Rd., Kansas City, MO, 64110, USA.
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10
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Thaenert A, Sevostyanova A, Chung CZ, Vargas-Rodriguez O, Melnikov SV, Söll D. Engineered mRNA-ribosome fusions for facile biosynthesis of selenoproteins. Proc Natl Acad Sci U S A 2024; 121:e2321700121. [PMID: 38442159 PMCID: PMC10945757 DOI: 10.1073/pnas.2321700121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/31/2024] [Indexed: 03/07/2024] Open
Abstract
Ribosomes are often used in synthetic biology as a tool to produce desired proteins with enhanced properties or entirely new functions. However, repurposing ribosomes for producing designer proteins is challenging due to the limited number of engineering solutions available to alter the natural activity of these enzymes. In this study, we advance ribosome engineering by describing a novel strategy based on functional fusions of ribosomal RNA (rRNA) with messenger RNA (mRNA). Specifically, we create an mRNA-ribosome fusion called RiboU, where the 16S rRNA is covalently attached to selenocysteine insertion sequence (SECIS), a regulatory RNA element found in mRNAs encoding selenoproteins. When SECIS sequences are present in natural mRNAs, they instruct ribosomes to decode UGA codons as selenocysteine (Sec, U) codons instead of interpreting them as stop codons. This enables ribosomes to insert Sec into the growing polypeptide chain at the appropriate site. Our work demonstrates that the SECIS sequence maintains its functionality even when inserted into the ribosome structure. As a result, the engineered ribosomes RiboU interpret UAG codons as Sec codons, allowing easy and site-specific insertion of Sec in a protein of interest with no further modification to the natural machinery of protein synthesis. To validate this approach, we use RiboU ribosomes to produce three functional target selenoproteins in Escherichia coli by site-specifically inserting Sec into the proteins' active sites. Overall, our work demonstrates the feasibility of creating functional mRNA-rRNA fusions as a strategy for ribosome engineering, providing a novel tool for producing Sec-containing proteins in live bacterial cells.
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Affiliation(s)
- Anna Thaenert
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
| | | | - Christina Z. Chung
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
| | | | - Sergey V. Melnikov
- Biosciences Institute, Newcastle University, Newcastle upon TyneNE2 4HH, United Kingdom
- Biosciences Institute, Newcastle University Medical School, Newcastle upon TyneNE2 4HH, United Kingdom
| | - Dieter Söll
- Department of Molecular Biophysics & Biochemistry, Yale University, New Haven, CT06511
- Department of Chemistry, Yale University, New Haven, CT06511
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11
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Zhang Y, Li H, Shen Y, Wang S, Tian L, Yin H, Shi J, Xing A, Zhang J, Ali U, Sami A, Chen X, Gao C, Zhao Y, Lyu Y, Wang X, Chen Y, Tian Z, Wu SB, Wu L. Readthrough events in plants reveal plasticity of stop codons. Cell Rep 2024; 43:113723. [PMID: 38300801 DOI: 10.1016/j.celrep.2024.113723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 10/02/2023] [Accepted: 01/15/2024] [Indexed: 02/03/2024] Open
Abstract
Stop codon readthrough (SCR) has important biological implications but remains largely uncharacterized. Here, we identify 1,009 SCR events in plants using a proteogenomic strategy. Plant SCR candidates tend to have shorter transcript lengths and fewer exons and splice variants than non-SCR transcripts. Mass spectrometry evidence shows that stop codons involved in SCR events can be recoded as 20 standard amino acids, some of which are also supported by suppressor tRNA analysis. We also observe multiple functional signals in 34 maize extended proteins and characterize the structural and subcellular localization changes in the extended protein of basic transcription factor 3. Furthermore, the SCR events exhibit non-conserved signature, and the extensions likely undergo protein-coding selection. Overall, our study not only characterizes that SCR events are commonly present in plants but also identifies the recoding plasticity of stop codons, which provides important insights into the flexibility of genetic decoding.
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Affiliation(s)
- Yuqian Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia
| | - Hehuan Li
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanting Shen
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shunxi Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Lei Tian
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Haoqiang Yin
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Jiawei Shi
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Anqi Xing
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634, USA
| | - Jinghua Zhang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Usman Ali
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Abdul Sami
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xueyan Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Chenxuan Gao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yangtao Zhao
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yajing Lyu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Xiaoxu Wang
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Yanhui Chen
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; College of Advanced Agriculture Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
| | - Shu-Biao Wu
- School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
| | - Liuji Wu
- National Key Laboratory of Wheat and Maize Crop Science, Collaborative Innovation Center of Henan Grain Crops, College of Agronomy, Henan Agricultural University, Zhengzhou 450046, Henan, China; School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
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12
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McNair K, Salamon P, Edwards RA, Segall AM. PRFect: a tool to predict programmed ribosomal frameshifts in prokaryotic and viral genomes. BMC Bioinformatics 2024; 25:82. [PMID: 38389044 PMCID: PMC10885494 DOI: 10.1186/s12859-024-05701-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 02/13/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND One of the stranger phenomena that can occur during gene translation is where, as a ribosome reads along the mRNA, various cellular and molecular properties contribute to stalling the ribosome on a slippery sequence and shifting the ribosome into one of the other two alternate reading frames. The alternate frame has different codons, so different amino acids are added to the peptide chain. More importantly, the original stop codon is no longer in-frame, so the ribosome can bypass the stop codon and continue to translate the codons past it. This produces a longer version of the protein, a fusion of the original in-frame amino acids, followed by all the alternate frame amino acids. There is currently no automated software to predict the occurrence of these programmed ribosomal frameshifts (PRF), and they are currently only identified by manual curation. RESULTS Here we present PRFect, an innovative machine-learning method for the detection and prediction of PRFs in coding genes of various types. PRFect combines advanced machine learning techniques with the integration of multiple complex cellular properties, such as secondary structure, codon usage, ribosomal binding site interference, direction, and slippery site motif. Calculating and incorporating these diverse properties posed significant challenges, but through extensive research and development, we have achieved a user-friendly approach. The code for PRFect is freely available, open-source, and can be easily installed via a single command in the terminal. Our comprehensive evaluations on diverse organisms, including bacteria, archaea, and phages, demonstrate PRFect's strong performance, achieving high sensitivity, specificity, and an accuracy exceeding 90%. The code for PRFect is freely available and installs with a single terminal command. CONCLUSION PRFect represents a significant advancement in the field of PRF detection and prediction, offering a powerful tool for researchers and scientists to unravel the intricacies of programmed ribosomal frameshifting in coding genes.
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Affiliation(s)
- Katelyn McNair
- Computational Science Research Center, San Diego State University, San Diego, CA, USA.
- Department of Computational Science, University of California Irvine, Irvine, CA, USA.
| | - Peter Salamon
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
- Department of Mathematics and Statistics, San Diego State University, San Diego, CA, USA
| | - Robert A Edwards
- College of Science and Engineering, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Anca M Segall
- Computational Science Research Center, San Diego State University, San Diego, CA, USA
- Department of Biology and Viral Information Institute, San Diego State University, San Diego, CA, USA
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13
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Xiao Y, Wang R, Han X, Wang W, Liang A. The Deficiency of Hypusinated eIF5A Decreases the Putrescine/Spermidine Ratio and Inhibits +1 Programmed Ribosomal Frameshifting during the Translation of Ty1 Retrotransposon in Saccharomyces cerevisiae. Int J Mol Sci 2024; 25:1766. [PMID: 38339043 PMCID: PMC10855120 DOI: 10.3390/ijms25031766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/12/2024] Open
Abstract
Programmed ribosomal frameshifting (PRF) exists in all branches of life that regulate gene expression at the translational level. The eukaryotic translation initiation factor 5A (eIF5A) is a highly conserved protein essential in all eukaryotes. It is identified initially as an initiation factor and functions broadly in translation elongation and termination. The hypusination of eIF5A is specifically required for +1 PRF at the shifty site derived from the ornithine decarboxylase antizyme 1 (OAZ1) in Saccharomyces cerevisiae. However, whether the regulation of +1 PRF by yeast eIF5A is universal remains unknown. Here, we found that Sc-eIF5A depletion decreased the putrescine/spermidine ratio. The re-introduction of Sc-eIF5A in yeast eIF5A mutants recovered the putrescine/spermidine ratio. In addition, the Sc-eIF5A depletion decreases +1 PRF during the decoding of Ty1 retrotransposon mRNA, but has no effect on -1 PRF during the decoding of L-A virus mRNA. The re-introduction of Sc-eIF5A in yeast eIF5A mutants restored the +1 PRF rate of Ty1. The inhibition of the hypusine modification of yeast eIF5A by GC7 treatment or by mutating the hypusination site Lys to Arg caused decreases of +1 PRF rates in the Ty1 retrotransposon. Furthermore, mutational studies of the Ty1 frameshifting element support a model where the efficient removal of ribosomal subunits at the first Ty1 frame 0 stop codon is required for the frameshifting of trailing ribosomes. This dependency is likely due to the unique position of the frame 0 stop codon distance from the slippery sequence of Ty1. The results showed that eIF5A is a trans-regulator of +1 PRF for Ty1 retrotransposon and could function universally in yeast.
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Affiliation(s)
- Yu Xiao
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Ruanlin Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Xiaxia Han
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Wei Wang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
| | - Aihua Liang
- Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Institute of Biotechnology, Shanxi University, Taiyuan 030006, China; (Y.X.); (R.W.); (X.H.)
- Shanxi Key Laboratory of Biotechnology, Taiyuan 030006, China
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14
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Chen SC, Jiang HY, Liao SR, Chen TX, Wang XQ. Complete mitochondrial genome of Stethoconus japonicus (Hemiptera: Miridae): Insights into the evolutionary traits within the family Miridae. Gene 2024; 891:147830. [PMID: 37758005 DOI: 10.1016/j.gene.2023.147830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 09/12/2023] [Accepted: 09/23/2023] [Indexed: 09/29/2023]
Abstract
The mitochondrial (mt) genome sequence of insects possesses numerous evolutionary traits. To better understand the evolution of mt genomes within the family Miridae, the complete mt genome of the predatory Japanese plant bug Stethoconus japonicus Schumacher was sequenced before undertaking a comparative analysis of all reported plant bug mt genomes. The mt genome of S. japonicus is a closed-circular and double-stranded DNA molecule of 16,274 bp (GenBank: MK341530), which consists of 13 protein-coding genes (PCGs), 2 rRNAs, 22 tRNAs and a putative control region (CR). Consistent with other plant bugs, the mt genome of S. japonicus is strongly AT-biased (73.49 %) with A-skewed (0.202) and C-skewed (-0.248). All 13 PCGs initiate translation using ATN codons and TAA served as complete stop codons for eight PCGs, which as incomplete stop codon "T-" for cox1, nad1, nad5-6 and "TA-" for cox2. Regarding other features, all 22 tRNAs could be folded into typical cloverleaf secondary structures. The control region is 1,717 bp and contains a long tandem repeat sequence of a 165 bp unit repeated six times. Similar sequence with variable number of tandemly repeated units from intra-genus CRs is a distinct characteristic of plant bug mt genomes. Phylogenetic relationships of 15 bugs were eventually analyzed based on Maximum likelihood (ML) and Bayesian inference (BI) methods using 17 mt genome sequences. In the phylogenetic trees, species from a same genus or subfamily are clustered into a branch with high supporting values.and the result suggest that Deraeocorinae is more closely related to Mirinae than Bryocorinae. Finally, this study revealed that mutation of tRNA anticodon is a useful phylogenetic marker that could be of significance for studies of evolutionary patterns.
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Affiliation(s)
- Shi-Chun Chen
- Tea Research Institute of Chongqing Academy of Agricultural Sciences, Chongqing, PR China.
| | - Hong-Yan Jiang
- Tea Research Institute of Chongqing Academy of Agricultural Sciences, Chongqing, PR China.
| | - Shu-Ran Liao
- Tea Research Institute of Chongqing Academy of Agricultural Sciences, Chongqing, PR China.
| | - Ting-Xu Chen
- Tea Research Institute of Chongqing Academy of Agricultural Sciences, Chongqing, PR China.
| | - Xiao-Qing Wang
- Tea Research Institute of Chongqing Academy of Agricultural Sciences, Chongqing, PR China.
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Ngo PHT, Ishida S, Busogi BB, Do H, Ledesma MA, Kar S, Ellington A. Changes in Coding and Efficiency through Modular Modifications to a One Pot PURE System for In Vitro Transcription and Translation. ACS Synth Biol 2023; 12:3771-3777. [PMID: 38050859 DOI: 10.1021/acssynbio.3c00461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
The incorporation of unnatural amino acids is an attractive method for improving or bringing new and novel functions in peptides and proteins. Cell-free protein synthesis using the Protein Synthesis Using Recombinant Elements (PURE) system is an attractive platform for efficient unnatural amino acid incorporation. In this work, we further adapted and modified the One Pot PURE to obtain a robust and modular system for enzymatic single-site-specific incorporation of an unnatural amino acid. We demonstrated the flexibility of this system through the introduction of two different orthogonal aminoacyl tRNA synthetase:tRNA pairs that suppressed two distinctive stop codons in separate reaction mixtures.
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Affiliation(s)
- Phuoc H T Ngo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Satoshi Ishida
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Bianca B Busogi
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Hannah Do
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Maximiliano A Ledesma
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Shaunak Kar
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
| | - Andrew Ellington
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas 78712, United States
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16
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Richardson MO, Eddy SR. ORFeus: a computational method to detect programmed ribosomal frameshifts and other non-canonical translation events. BMC Bioinformatics 2023; 24:471. [PMID: 38093195 PMCID: PMC10720069 DOI: 10.1186/s12859-023-05602-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 12/05/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND In canonical protein translation, ribosomes initiate translation at a specific start codon, maintain a single reading frame throughout elongation, and terminate at the first in-frame stop codon. However, ribosomal behavior can deviate at each of these steps, sometimes in a programmed manner. Certain mRNAs contain sequence and structural elements that cause ribosomes to begin translation at alternative start codons, shift reading frame, read through stop codons, or reinitiate on the same mRNA. These processes represent important translational control mechanisms that can allow an mRNA to encode multiple functional protein products or regulate protein expression. The prevalence of these events remains uncertain, due to the difficulty of systematic detection. RESULTS We have developed a computational model to infer non-canonical translation events from ribosome profiling data. CONCLUSION ORFeus identifies known examples of alternative open reading frames and recoding events across different organisms and enables transcriptome-wide searches for novel events.
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Affiliation(s)
- Mary O Richardson
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Sean R Eddy
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA.
- Howard Hughes Medical Institute, Harvard University, Cambridge, MA, USA.
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17
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Meineke B, Heimgärtner J, Caridha R, Block MF, Kimler KJ, Pires MF, Landreh M, Elsässer SJ. Dual stop codon suppression in mammalian cells with genomically integrated genetic code expansion machinery. Cell Rep Methods 2023; 3:100626. [PMID: 37935196 PMCID: PMC10694491 DOI: 10.1016/j.crmeth.2023.100626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2023] [Revised: 08/22/2023] [Accepted: 10/12/2023] [Indexed: 11/09/2023]
Abstract
Stop codon suppression using dedicated tRNA/aminoacyl-tRNA synthetase (aaRS) pairs allows for genetically encoded, site-specific incorporation of non-canonical amino acids (ncAAs) as chemical handles for protein labeling and modification. Here, we demonstrate that piggyBac-mediated genomic integration of archaeal pyrrolysine tRNA (tRNAPyl)/pyrrolysyl-tRNA synthetase (PylRS) or bacterial tRNA/aaRS pairs, using a modular plasmid design with multi-copy tRNA arrays, allows for homogeneous and efficient genetically encoded ncAA incorporation in diverse mammalian cell lines. We assess opportunities and limitations of using ncAAs for fluorescent labeling applications in stable cell lines. We explore suppression of ochre and opal stop codons and finally incorporate two distinct ncAAs with mutually orthogonal click chemistries for site-specific, dual-fluorophore labeling of a cell surface receptor on live mammalian cells.
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Affiliation(s)
- Birthe Meineke
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden.
| | - Johannes Heimgärtner
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Rozina Caridha
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Matthias F Block
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Kyle J Kimler
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Maria F Pires
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden
| | - Michael Landreh
- Department of Microbiology, Tumor and Cell Biology, Science for Life Laboratory, Karolinska Institutet, 17165 Stockholm, Sweden
| | - Simon J Elsässer
- Science for Life Laboratory, Karolinska Institutet, Department of Medical Biochemistry and Biophysics, Division of Genome Biology, 17165 Stockholm, Sweden; Ming Wai Lau Centre for Reparative Medicine, Stockholm Node, Karolinska Institutet, 17165 Stockholm, Sweden.
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18
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Kar D, Manna D, Manjunath LE, Singh A, Som S, Vasu K, Eswarappa SM. Kinetics of Translating Ribosomes Determine the Efficiency of Programmed Stop Codon Readthrough. J Mol Biol 2023; 435:168274. [PMID: 37714299 DOI: 10.1016/j.jmb.2023.168274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Revised: 08/15/2023] [Accepted: 09/08/2023] [Indexed: 09/17/2023]
Abstract
During translation, a stop codon on the mRNA signals the ribosomes to terminate the process. In certain mRNAs, the termination fails due to the recoding of the canonical stop codon, and ribosomes continue translation to generate C-terminally extended protein. This process, termed stop codon readthrough (SCR), regulates several cellular functions. SCR is driven by elements/factors that act immediately downstream of the stop codon. Here, we have analysed the process of SCR using a simple mathematical model to investigate how the kinetics of translating ribosomes influences the efficiency of SCR. Surprisingly, the analysis revealed that the rate of translation inversely regulates the efficiency of SCR. We tested this prediction experimentally in mammalian AGO1 and MTCH2 mRNAs. Reduction in translation either globally by harringtonine or locally by rare codons caused an increase in the efficiency of SCR. Thus, our study has revealed a hitherto unknown mode of regulation of SCR.
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Affiliation(s)
- Debaleena Kar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/debaleenak8
| | - Debraj Manna
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/DebrajManna27
| | - Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/emlekha
| | - Anumeha Singh
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/Anumehasingh25
| | - Saubhik Som
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India. https://twitter.com/SaubhikSom
| | - Kirtana Vasu
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India.
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19
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Babkin I, Tikunov A, Morozova V, Matveev A, Morozov VV, Tikunova N. Genomes of a Novel Group of Phages That Use Alternative Genetic Code Found in Human Gut Viromes. Int J Mol Sci 2023; 24:15302. [PMID: 37894982 PMCID: PMC10607447 DOI: 10.3390/ijms242015302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 10/09/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
Metagenomics provides detection of phage genome sequences in various microbial communities. However, the use of alternative genetic codes by some phages precludes the correct analysis of their genomes. In this study, the unusual phage genome (phAss-1, 135,976 bp) was found after the de novo assembly of the human gut virome. Genome analysis revealed the presence of the TAG stop codons in 41 ORFs, including characteristic phage ORFs, and three genes of suppressor tRNA. Comparative analysis indicated that no phages with similar genomes were described. However, two phage genomes (BK046881_ctckW2 and BK025033_ct6IQ4) with substantial similarity to phAss-1 were extracted from the human gut metagenome data. These two complete genomes demonstrated 82.7% and 86.4% of nucleotide identity, respectively, similar genome synteny to phAss-1, the presence of suppressor tRNA genes and suppressor TAG stop codons in many characteristic phage ORFs. These data indicated that phAss-1, BK046881_ctckW2, and BK025033_ct6IQ4 are distinct species within the proposed Phassvirus genus. Moreover, a monophyletic group of divergent phage genomes containing the proposed Phassvirus genus was found among metagenome data. Several phage genomes from the group also contain ORFs with suppressor TAG stop codons, indicating the need to use various translation tables when depositing phage genomes in GenBank.
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Affiliation(s)
- Igor Babkin
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Artem Tikunov
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
| | - Vera Morozova
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
| | - Andrey Matveev
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
| | - Vitaliy V. Morozov
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
| | - Nina Tikunova
- Federal State Public Scientific Institution «Institute of Chemical Biology and Fundamental Medicine», Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia; (I.B.); (A.T.); (V.M.); (A.M.); (V.V.M.)
- Department of Natural Sciences, Novosibirsk State University, 630090 Novosibirsk, Russia
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20
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Li R, Sun K, Tuplin A, Harris M. A structural and functional analysis of opal stop codon translational readthrough during Chikungunya virus replication. J Gen Virol 2023; 104:10.1099/jgv.0.001909. [PMID: 37862073 PMCID: PMC7615711 DOI: 10.1099/jgv.0.001909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2023] Open
Abstract
Chikungunya virus (CHIKV) is an alphavirus, transmitted by Aedes species mosquitoes. The CHIKV single-stranded positive-sense RNA genome contains two open reading frames, coding for the non-structural (nsP) and structural proteins of the virus. The non-structural polyprotein precursor is proteolytically cleaved to generate nsP1-4. Intriguingly, most isolates of CHIKV (and other alphaviruses) possess an opal stop codon close to the 3' end of the nsP3 coding sequence and translational readthrough is necessary to produce full-length nsP3 and the nsP4 RNA polymerase. Here we investigate the role of this stop codon by replacing the arginine codon with each of the three stop codons in the context of both a subgenomic replicon and infectious CHIKV. Both opal and amber stop codons were tolerated in mammalian cells, but the ochre was not. In mosquito cells all three stop codons were tolerated. Using SHAPE analysis we interrogated the structure of a putative stem loop 3' of the stop codon and used mutagenesis to probe the importance of a short base-paired region at the base of this structure. Our data reveal that this stem is not required for stop codon translational readthrough, and we conclude that other factors must facilitate this process to permit productive CHIKV replication.
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Affiliation(s)
- Raymond Li
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, UK
| | | | - Andrew Tuplin
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, UK
| | - Mark Harris
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, and Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, West Yorkshire, LS2 9JT, UK
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21
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Valášek LS, Kučerová M, Zeman J, Beznosková P. Cysteine tRNA acts as a stop codon readthrough-inducing tRNA in the human HEK293T cell line. RNA 2023; 29:1379-1387. [PMID: 37221013 PMCID: PMC10573299 DOI: 10.1261/rna.079688.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 05/12/2023] [Indexed: 05/25/2023]
Abstract
Under certain circumstances, any of the three termination codons can be read through by a near-cognate tRNA; i.e., a tRNA whose two out of three anticodon nucleotides base pair with those of the stop codon. Unless programed to synthetize C-terminally extended protein variants with expanded physiological roles, readthrough represents an undesirable translational error. On the other side of a coin, a significant number of human genetic diseases is associated with the introduction of nonsense mutations (premature termination codons [PTCs]) into coding sequences, where stopping is not desirable. Here, the tRNA's ability to induce readthrough opens up the intriguing possibility of mitigating the deleterious effects of PTCs on human health. In yeast, the UGA and UAR stop codons were described to be read through by four readthrough-inducing rti-tRNAs-tRNATrp and tRNACys, and tRNATyr and tRNAGln, respectively. The readthrough-inducing potential of tRNATrp and tRNATyr was also observed in human cell lines. Here, we investigated the readthrough-inducing potential of human tRNACys in the HEK293T cell line. The tRNACys family consists of two isoacceptors, one with ACA and the other with GCA anticodons. We selected nine representative tRNACys isodecoders (differing in primary sequence and expression level) and tested them using dual luciferase reporter assays. We found that at least two tRNACys can significantly elevate UGA readthrough when overexpressed. This indicates a mechanistically conserved nature of rti-tRNAs between yeast and human, supporting the idea that they could be used in the PTC-associated RNA therapies.
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MESH Headings
- Humans
- Codon, Terminator/genetics
- Cysteine/genetics
- Cysteine/metabolism
- HEK293 Cells
- Saccharomyces cerevisiae/genetics
- RNA, Transfer, Cys/metabolism
- RNA, Transfer, Trp/metabolism
- RNA, Transfer, Tyr
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Anticodon
- Codon, Nonsense/genetics
- Protein Biosynthesis
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Affiliation(s)
- Leoš Shivaya Valášek
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Michaela Kučerová
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Jakub Zeman
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
| | - Petra Beznosková
- Laboratory of Regulation of Gene Expression, Institute of Microbiology ASCR, 142 20 Prague, the Czech Republic
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22
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Hoffman KS, Chung CZ, Mukai T, Krahn N, Jiang HK, Balasuriya N, O'Donoghue P, Söll D. Recoding UAG to selenocysteine in Saccharomyces cerevisiae. RNA 2023; 29:1400-1410. [PMID: 37279998 PMCID: PMC10573291 DOI: 10.1261/rna.079658.123] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 05/16/2023] [Indexed: 06/08/2023]
Abstract
Unique chemical and physical properties are introduced by inserting selenocysteine (Sec) at specific sites within proteins. Recombinant and facile production of eukaryotic selenoproteins would benefit from a yeast expression system; however, the selenoprotein biosynthetic pathway was lost in the evolution of the kingdom Fungi as it diverged from its eukaryotic relatives. Based on our previous development of efficient selenoprotein production in bacteria, we designed a novel Sec biosynthesis pathway in Saccharomyces cerevisiae using Aeromonas salmonicida translation components. S. cerevisiae tRNASer was mutated to resemble A. salmonicida tRNASec to allow recognition by S. cerevisiae seryl-tRNA synthetase as well as A. salmonicida selenocysteine synthase (SelA) and selenophosphate synthetase (SelD). Expression of these Sec pathway components was then combined with metabolic engineering of yeast to enable the production of active methionine sulfate reductase enzyme containing genetically encoded Sec. Our report is the first demonstration that yeast is capable of selenoprotein production by site-specific incorporation of Sec.
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Affiliation(s)
- Kyle S Hoffman
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Christina Z Chung
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Takahito Mukai
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Natalie Krahn
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Han-Kai Jiang
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
| | - Nileeka Balasuriya
- Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, Ontario N6A 3K7, Canada
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 3K7, Canada
| | - Dieter Söll
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06511, USA
- Department of Chemistry, Yale University, New Haven, Connecticut 06511, USA
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23
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Trexler M, Bányai L, Kerekes K, Patthy L. Evolution of termination codons of proteins and the TAG-TGA paradox. Sci Rep 2023; 13:14294. [PMID: 37653005 PMCID: PMC10471768 DOI: 10.1038/s41598-023-41410-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023] Open
Abstract
In most eukaryotes and prokaryotes TGA is used at a significantly higher frequency than TAG as termination codon of protein-coding genes. Although this phenomenon has been recognized several years ago, there is no generally accepted explanation for the TAG-TGA paradox. Our analyses of human mutation data revealed that out of the eighteen sense codons that can give rise to a nonsense codon by single base substitution, the CGA codon is exceptional: it gives rise to the TGA stop codon at an order of magnitude higher rate than the other codons. Here we propose that the TAG-TGA paradox is due to methylation and hypermutabilty of CpG dinucleotides. In harmony with this explanation, we show that the coding genomes of organisms with strong CpG methylation have a significant bias for TGA whereas those from organisms that lack CpG methylation use TGA and TAG termination codons with similar probability.
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Affiliation(s)
- Mária Trexler
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Bányai
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - Krisztina Kerekes
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary
| | - László Patthy
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, 1117, Hungary.
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24
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Song Z, Zhang G, Huang S, Liu Y, Li G, Zhou X, Sun J, Gao P, Chen Y, Huang X, Liu J, Wang X. PE-STOP: A versatile tool for installing nonsense substitutions amenable for precise reversion. J Biol Chem 2023; 299:104942. [PMID: 37343700 PMCID: PMC10365944 DOI: 10.1016/j.jbc.2023.104942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 06/08/2023] [Accepted: 06/11/2023] [Indexed: 06/23/2023] Open
Abstract
The rapid advances in genome editing technologies have revolutionized the study of gene functions in cell or animal models. The recent generation of double-stranded DNA cleavage-independent base editors has been suitably adapted for interrogation of protein-coding genes on the basis of introducing premature stop codons or disabling the start codons. However, such versions of stop/start codon-oriented genetic tools still present limitations on their versatility, base-level precision, and target specificity. Here, we exploit a newly developed prime editor (PE) that differs from base editors by its adoption of a reverse transcriptase activity, which enables incorporation of various types of precise edits templated by a specialized prime editing guide RNA. Based on such a versatile platform, we established a prime editing-empowered method (PE-STOP) for installation of nonsense substitutions, providing a complementary approach to the present gene-targeting tools. PE-STOP is bioinformatically predicted to feature substantially expanded coverage in the genome space. In practice, PE-STOP introduces stop codons with good efficiencies in human embryonic kidney 293T and N2a cells (with medians of 29% [ten sites] and 25% [four sites] editing efficiencies, respectively), while exhibiting minimal off-target effects and high on-target precision. Furthermore, given the fact that PE installs prime editing guide RNA-templated mutations, we introduce a unique strategy for precise genetic rescue of PE-STOP-dependent nonsense mutation via the same PE platform. Altogether, the present work demonstrates a versatile and specific tool for gene inactivation and for functional interrogation of nonsense mutations.
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Affiliation(s)
- Ziguo Song
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Guiquan Zhang
- Zhejiang Lab, Hangzhou, Zhejiang, China; State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center at Medical School of Nanjing University, Nanjing, China
| | - Shuhong Huang
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Yao Liu
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Guanglei Li
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xianhui Zhou
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Jiayuan Sun
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Pengfei Gao
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Yulin Chen
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Livestock Biology, Northwest A&F University, Yangling, Shaanxi, China
| | - Xingxu Huang
- Zhejiang Lab, Hangzhou, Zhejiang, China; School of Life Science and Technology, ShanghaiTech University, Shanghai, China; CAS Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China
| | - Jianghuai Liu
- State Key Laboratory of Pharmaceutical Biotechnology and MOE Key Laboratory of Model Animals for Disease Study, Model Animal Research Center at Medical School of Nanjing University, Nanjing, China.
| | - Xiaolong Wang
- International Joint Agriculture Research Center for Animal Bio-Breeding of Ministry of Agriculture and Rural Affairs, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China; Key Laboratory of Livestock Biology, Northwest A&F University, Yangling, Shaanxi, China.
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25
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Lahiri P, Martin MS, Lino BR, Scheck RA, Van Deventer JA. Dual Noncanonical Amino Acid Incorporation Enabling Chemoselective Protein Modification at Two Distinct Sites in Yeast. Biochemistry 2023; 62:2098-2114. [PMID: 37377426 DOI: 10.1021/acs.biochem.2c00711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2023]
Abstract
Incorporation of more than one noncanonical amino acid (ncAA) within a single protein endows the resulting construct with multiple useful features such as augmented molecular recognition or covalent cross-linking capabilities. Herein, for the first time, we demonstrate the incorporation of two chemically distinct ncAAs into proteins biosynthesized in Saccharomyces cerevisiae. To complement ncAA incorporation in response to the amber (TAG) stop codon in yeast, we evaluated opal (TGA) stop codon suppression using three distinct orthogonal translation systems. We observed selective TGA readthrough without detectable cross-reactivity from host translation components. Readthrough efficiency at TGA was modulated by factors including the local nucleotide environment, gene deletions related to the translation process, and the identity of the suppressor tRNA. These observations facilitated systematic investigation of dual ncAA incorporation in both intracellular and yeast-displayed protein constructs, where we observed efficiencies up to 6% of wild-type protein controls. The successful display of doubly substituted proteins enabled the exploration of two critical applications on the yeast surface─(A) antigen binding functionality and (B) chemoselective modification with two distinct chemical probes through sequential application of two bioorthogonal click chemistry reactions. Lastly, by utilizing a soluble form of a doubly substituted construct, we validated the dual incorporation system using mass spectrometry and demonstrated the feasibility of conducting selective labeling of the two ncAAs sequentially using a "single-pot" approach. Overall, our work facilitates the addition of a 22nd amino acid to the genetic code of yeast and expands the scope of applications of ncAAs for basic biological research and drug discovery.
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Affiliation(s)
- Priyanka Lahiri
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
| | - Meghan S Martin
- Chemistry Department, Tufts University, Medford, Massachusetts 02155, United States
| | - Briana R Lino
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
| | - Rebecca A Scheck
- Chemistry Department, Tufts University, Medford, Massachusetts 02155, United States
| | - James A Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
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26
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Pfennig A, Lomsadze A, Borodovsky M. MgCod: Gene Prediction in Phage Genomes with Multiple Genetic Codes. J Mol Biol 2023; 435:168159. [PMID: 37244571 DOI: 10.1016/j.jmb.2023.168159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/19/2023] [Accepted: 05/21/2023] [Indexed: 05/29/2023]
Abstract
Massive sequencing of microbiomes has led to the discovery of a large number of phage genomes with intermittent stop codon recoding. We have developed a computational tool, MgCod, that identifies genomic regions (blocks) with distinct stop codon recoding simultaneously with the prediction of protein-coding regions. When MgCod was used to scan a large volume of human metagenomic contigs hundreds of viral contigs with intermittent stop codon recoding were revealed. Many of these contigs originated from genomes of known crAssphages. Further analyses had shown that intermittent recoding was associated with subtle patterns in the organization of protein-coding genes, such as 'single-coding' and 'dual-coding'. The dual-coding genes, clustered into blocks, could be translated by two alternative codes producing nearly identical proteins. It was observed that the dual-coded blocks were enriched with the early-stage phage genes, while the late-stage genes were residing in the single-coded blocks. MgCod can identify types of stop codon recoding in novel genomic sequences in parallel with gene prediction. It is available for download from https://github.com/gatech-genemark/MgCod.
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Affiliation(s)
- Aaron Pfennig
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Alexandre Lomsadze
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
| | - Mark Borodovsky
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA; School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA.
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27
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Sherlock ME, Baquero Galvis L, Vicens Q, Kieft JS, Jagannathan S. Principles, mechanisms, and biological implications of translation termination-reinitiation. RNA 2023; 29:865-884. [PMID: 37024263 PMCID: PMC10275272 DOI: 10.1261/rna.079375.122] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 03/28/2023] [Indexed: 06/11/2023]
Abstract
The gene expression pathway from DNA sequence to functional protein is not as straightforward as simple depictions of the central dogma might suggest. Each step is highly regulated, with complex and only partially understood molecular mechanisms at play. Translation is one step where the "one gene-one protein" paradigm breaks down, as often a single mature eukaryotic mRNA leads to more than one protein product. One way this occurs is through translation reinitiation, in which a ribosome starts making protein from one initiation site, translates until it terminates at a stop codon, but then escapes normal recycling steps and subsequently reinitiates at a different downstream site. This process is now recognized as both important and widespread, but we are only beginning to understand the interplay of factors involved in termination, recycling, and initiation that cause reinitiation events. There appear to be several ways to subvert recycling to achieve productive reinitiation, different types of stresses or signals that trigger this process, and the mechanism may depend in part on where the event occurs in the body of an mRNA. This perspective reviews the unique characteristics and mechanisms of reinitiation events, highlights the similarities and differences between three major scenarios of reinitiation, and raises outstanding questions that are promising avenues for future research.
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Affiliation(s)
- Madeline E Sherlock
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Laura Baquero Galvis
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Quentin Vicens
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Jeffrey S Kieft
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
| | - Sujatha Jagannathan
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
- RNA Bioscience Initiative, University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, USA
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28
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Seki K, Galindo JL, Karim AS, Jewett MC. A Cell-Free Gene Expression Platform for Discovering and Characterizing Stop Codon Suppressing tRNAs. ACS Chem Biol 2023; 18:1324-1334. [PMID: 37257197 DOI: 10.1021/acschembio.3c00051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Non-canonical amino acids (ncAAs) can be incorporated into peptides and proteins to create new properties and functions. Site-specific ncAA incorporation is typically enabled by orthogonal translation systems comprising a stop codon suppressing tRNA (typically UAG), an aminoacyl-tRNA synthetase, and an ncAA of interest. Unfortunately, methods to discover and characterize suppressor tRNAs are limited because of laborious and time-consuming workflows in living cells. In this work, we develop anEscherichia coli crude extract-based cell-free gene expression system to rapidly express and characterize functional suppressor tRNAs. Our approach co-expresses orthogonal tRNAs using endogenous machinery alongside a stop-codon containing superfolder green fluorescent protein (sfGFP) reporter, which can be used as a simple read-out for suppression. As a model, we evaluate the UAG and UAA suppressing activity of several orthogonal tRNAs. Then, we demonstrate that co-transcription of two mutually orthogonal tRNAs can direct the incorporation of two unique ncAAs within a single modified sfGFP. Finally, we show that the cell-free workflow can be used to discover putative UAG-suppressor tRNAs found in metagenomic data, which are nonspecifically recognized by endogenous aminoacyl-tRNA synthetases. We anticipate that our cell-free system will accelerate the development of orthogonal translation systems for synthetic biology.
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Affiliation(s)
- Kosuke Seki
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Joey L Galindo
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Ashty S Karim
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
| | - Michael C Jewett
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States
- Chemistry of Life Processes Institute, Northwestern University, Evanston, Illinois 60208, United States
- Center for Synthetic Biology, Northwestern University, Evanston, Illinois 60208, United States
- Robert H. Lurie Comprehensive Cancer Center and Simpson Querrey Institute, Northwestern University, Chicago, Illinois 60611, United States
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29
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Gaydukova SA, Moldovan MA, Vallesi A, Heaphy SM, Atkins JF, Gelfand MS, Baranov PV. Nontriplet feature of genetic code in Euplotes ciliates is a result of neutral evolution. Proc Natl Acad Sci U S A 2023; 120:e2221683120. [PMID: 37216548 PMCID: PMC10235951 DOI: 10.1073/pnas.2221683120] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 04/12/2023] [Indexed: 05/24/2023] Open
Abstract
The triplet nature of the genetic code is considered a universal feature of known organisms. However, frequent stop codons at internal mRNA positions in Euplotes ciliates ultimately specify ribosomal frameshifting by one or two nucleotides depending on the context, thus posing a nontriplet feature of the genetic code of these organisms. Here, we sequenced transcriptomes of eight Euplotes species and assessed evolutionary patterns arising at frameshift sites. We show that frameshift sites are currently accumulating more rapidly by genetic drift than they are removed by weak selection. The time needed to reach the mutational equilibrium is several times longer than the age of Euplotes and is expected to occur after a several-fold increase in the frequency of frameshift sites. This suggests that Euplotes are at an early stage of the spread of frameshifting in expression of their genome. In addition, we find the net fitness burden of frameshift sites to be noncritical for the survival of Euplotes. Our results suggest that fundamental genome-wide changes such as a violation of the triplet character of genetic code can be introduced and maintained solely by neutral evolution.
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Affiliation(s)
- Sofya A. Gaydukova
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow199911, Russia
| | - Mikhail A. Moldovan
- A. A. Kharkevich Institute for Information Transmission Problems RAS, Moscow127051, Russia
| | - Adriana Vallesi
- Laboratory of Eukaryotic Microbiology and Animal Biology, School of Biosciences and Veterinary Medicine, University of Camerino, Camerino62032, Italy
| | - Stephen M. Heaphy
- School of Biochemistry and Cell Biology, University College Cork, CorkT12 XF62, Ireland
| | - John F. Atkins
- School of Biochemistry and Cell Biology, University College Cork, CorkT12 XF62, Ireland
- Department of Human Genetics, University of Utah, Salt Lake City, UT84112
| | - Mikhail S. Gelfand
- A. A. Kharkevich Institute for Information Transmission Problems RAS, Moscow127051, Russia
| | - Pavel V. Baranov
- School of Biochemistry and Cell Biology, University College Cork, CorkT12 XF62, Ireland
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30
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Leroy C, Spelier S, Essonghe NC, Poix V, Kong R, Gizzi P, Bourban C, Amand S, Bailly C, Guilbert R, Hannebique D, Persoons P, Arhant G, Prévotat A, Reix P, Hubert D, Gérardin M, Chamaillard M, Prevarskaya N, Rebuffat S, Shapovalov G, Beekman J, Lejeune F. Use of 2,6-diaminopurine as a potent suppressor of UGA premature stop codons in cystic fibrosis. Mol Ther 2023; 31:970-985. [PMID: 36641622 PMCID: PMC10124085 DOI: 10.1016/j.ymthe.2023.01.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 12/10/2022] [Accepted: 01/12/2023] [Indexed: 01/16/2023] Open
Abstract
Nonsense mutations are responsible for around 10% of cases of genetic diseases, including cystic fibrosis. 2,6-diaminopurine (DAP) has recently been shown to promote efficient readthrough of UGA premature stop codons. In this study, we show that DAP can correct a nonsense mutation in the Cftr gene in vivo in a new CF mouse model, in utero, and through breastfeeding, thanks, notably, to adequate pharmacokinetic properties. DAP turns out to be very stable in plasma and is distributed throughout the body. The ability of DAP to correct various endogenous UGA nonsense mutations in the CFTR gene and to restore its function in mice, in organoids derived from murine or patient cells, and in cells from patients with cystic fibrosis reveals the potential of such readthrough-stimulating molecules in developing a therapeutic approach. The fact that correction by DAP of certain nonsense mutations reaches a clinically relevant level, as judged from previous studies, makes the use of this compound all the more attractive.
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Affiliation(s)
- Catherine Leroy
- University Lille, CNRS, INSERM, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, 59000 Lille, France; Unité Tumorigenèse et Résistance aux Traitements, Institut Pasteur de Lille, 59000 Lille, France
| | - Sacha Spelier
- Pediatric Respiratory Medicine, Wilhelmina Children's Hospital, University Medical Center, Utrecht University, 3584 EA Utrecht, the Netherlands; Regenerative Medicine Utrecht, University Medical Center, Utrecht University, 3584 CT Utrecht, the Netherlands; Center for Living Technologies, University Medical Center, Utrecht University, 3584 CT Utrecht, the Netherlands
| | - Nadège Charlene Essonghe
- University Lille, INSERM, U1003-PHYCEL-Physiologie Cellulaire, 59000 Lille, France; Laboratory of Excellence, Ion Channels Science and Therapeutics, 59655 Villeneuve d'Ascq, France
| | - Virginie Poix
- University Lille, CNRS, INSERM, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, 59000 Lille, France; Unité Tumorigenèse et Résistance aux Traitements, Institut Pasteur de Lille, 59000 Lille, France
| | - Rebekah Kong
- University Lille, CNRS, INSERM, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, 59000 Lille, France; Unité Tumorigenèse et Résistance aux Traitements, Institut Pasteur de Lille, 59000 Lille, France
| | - Patrick Gizzi
- Plateforme de Chimie Biologique Intégrative de Strasbourg, UAR 3286 CNRS-Université de Strasbourg, 67404 Illkirch, France
| | - Claire Bourban
- Plateforme de Chimie Biologique Intégrative de Strasbourg, UAR 3286 CNRS-Université de Strasbourg, 67404 Illkirch, France
| | - Séverine Amand
- Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Laboratory of Molecules of Communication and Adaptation of Microorganisms (MCAM), UMR 7245 CNRS-MNHN, CP 54, 57 Rue Cuvier, 75005 Paris, France
| | - Christine Bailly
- Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Laboratory of Molecules of Communication and Adaptation of Microorganisms (MCAM), UMR 7245 CNRS-MNHN, CP 54, 57 Rue Cuvier, 75005 Paris, France
| | - Romain Guilbert
- Institut Pasteur de Lille-PLEHTA (Plateforme d'Expérimentation et de Haute Technologie Animale), 59019 Lille, France
| | - David Hannebique
- Institut Pasteur de Lille-PLEHTA (Plateforme d'Expérimentation et de Haute Technologie Animale), 59019 Lille, France
| | - Philippe Persoons
- Institut Pasteur de Lille-PLEHTA (Plateforme d'Expérimentation et de Haute Technologie Animale), 59019 Lille, France
| | - Gwenaëlle Arhant
- University Lille, CNRS, INSERM, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, 59000 Lille, France; Unité Tumorigenèse et Résistance aux Traitements, Institut Pasteur de Lille, 59000 Lille, France
| | - Anne Prévotat
- University Lille, Clinique des Maladies Respiratoires, CRCM Hôpital Calmette, CHRU Lille, 59000 Lille, France
| | - Philippe Reix
- CRCM Pédiatrique Lyon, Hôpital Femme Mère Enfant, Hospices Civils de Lyon, UMR 5558 (EMET), CNRS, LBBE, Université de Lyon, 69622 Villeurbanne, France
| | - Dominique Hubert
- Pulmonary Department and Adult CF Centre, Cochin Hospital, AP-HP, Paris, France
| | - Michèle Gérardin
- CF Pediatric Centre, Robert Debré Hospital, AP-HP, 75019 Paris, France
| | - Mathias Chamaillard
- University Lille, INSERM, U1003-PHYCEL-Physiologie Cellulaire, 59000 Lille, France
| | - Natalia Prevarskaya
- University Lille, INSERM, U1003-PHYCEL-Physiologie Cellulaire, 59000 Lille, France; Laboratory of Excellence, Ion Channels Science and Therapeutics, 59655 Villeneuve d'Ascq, France
| | - Sylvie Rebuffat
- Muséum National d'Histoire Naturelle, Centre National de la Recherche Scientifique, Laboratory of Molecules of Communication and Adaptation of Microorganisms (MCAM), UMR 7245 CNRS-MNHN, CP 54, 57 Rue Cuvier, 75005 Paris, France
| | - George Shapovalov
- University Lille, INSERM, U1003-PHYCEL-Physiologie Cellulaire, 59000 Lille, France; Laboratory of Excellence, Ion Channels Science and Therapeutics, 59655 Villeneuve d'Ascq, France
| | - Jeffrey Beekman
- Pediatric Respiratory Medicine, Wilhelmina Children's Hospital, University Medical Center, Utrecht University, 3584 EA Utrecht, the Netherlands; Regenerative Medicine Utrecht, University Medical Center, Utrecht University, 3584 CT Utrecht, the Netherlands; Center for Living Technologies, University Medical Center, Utrecht University, 3584 CT Utrecht, the Netherlands
| | - Fabrice Lejeune
- University Lille, CNRS, INSERM, UMR9020-U1277-CANTHER-Cancer Heterogeneity Plasticity and Resistance to Therapies, 59000 Lille, France; Unité Tumorigenèse et Résistance aux Traitements, Institut Pasteur de Lille, 59000 Lille, France.
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Rehfeld F, Eitson JL, Ohlson MB, Chang TC, Schoggins JW, Mendell JT. CRISPR screening reveals a dependency on ribosome recycling for efficient SARS-CoV-2 programmed ribosomal frameshifting and viral replication. Cell Rep 2023; 42:112076. [PMID: 36753415 PMCID: PMC9884621 DOI: 10.1016/j.celrep.2023.112076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/21/2022] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
During translation of the genomic RNA of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus in the COVID-19 pandemic, host ribosomes undergo programmed ribosomal frameshifting (PRF) at a conserved structural element. Although PRF is essential for coronavirus replication, host factors that regulate this process have not yet been identified. Here we perform genome-wide CRISPR-Cas9 knockout screens to identify regulators of SARS-CoV-2 PRF. These screens reveal that loss of ribosome recycling factors markedly decreases frameshifting efficiency and impairs SARS-CoV-2 viral replication. Mutational studies support a model wherein efficient removal of ribosomal subunits at the ORF1a stop codon is required for frameshifting of trailing ribosomes. This dependency upon ribosome recycling is not observed with other non-pathogenic human betacoronaviruses and is likely due to the unique position of the ORF1a stop codon in the SARS clade of coronaviruses. These findings therefore uncover host factors that support efficient SARS-CoV-2 translation and replication.
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Affiliation(s)
- Frederick Rehfeld
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jennifer L Eitson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maikke B Ohlson
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Tsung-Cheng Chang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John W Schoggins
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Joshua T Mendell
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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Zackin MT, Stieglitz JT, Van Deventer JA. Genome-Wide Screen for Enhanced Noncanonical Amino Acid Incorporation in Yeast. ACS Synth Biol 2022; 11:3669-3680. [PMID: 36346914 PMCID: PMC10065164 DOI: 10.1021/acssynbio.2c00267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Numerous applications of noncanonical amino acids (ncAAs) in basic biology and therapeutic development require efficient protein biosynthesis using an expanded genetic code. However, achieving such incorporation at repurposed stop codons in cells is generally inefficient and limited by complex cellular processes that preserve the fidelity of protein synthesis. A more comprehensive understanding of the processes that contribute to ncAA incorporation would aid in the development of genomic engineering strategies for augmenting genetic code manipulation. In this work, we used a series of fluorescent reporters to screen a pooled Saccharomyces cerevisiae molecular barcoded yeast knockout (YKO) collection. Fluorescence-activated cell sorting enabled isolation of strains encoding single-gene deletions exhibiting improved ncAA incorporation efficiency in response to the amber (TAG) stop codon; 55 unique candidate deletions were identified. The deleted genes encoded for proteins that participate in diverse cellular processes, including many genes that have no known connection with protein translation. We then verified that two knockouts, yil014c-aΔ and alo1Δ, exhibited improved ncAA incorporation efficiency starting from independently acquired strains possessing the knockouts. Using additional orthogonal translation systems and ncAAs, we determined that yil014c-aΔ and alo1Δ enhance ncAA incorporation efficiency without loss of fidelity over a wide range of conditions. Our findings highlight opportunities for further modulating gene expression with genetic, genomic, and synthetic biology approaches to improve ncAA incorporation efficiency. In addition, these discoveries have the potential to enhance our fundamental understanding of protein translation. Ultimately, cells that efficiently biosynthesize ncAA-containing proteins will streamline the realization of applications utilizing expanded genetic codes ranging from basic biology to drug discovery.
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Affiliation(s)
- Matthew T. Zackin
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, USA
| | - Jessica T. Stieglitz
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, USA
| | - James A. Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, USA
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, USA
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33
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Abstract
One gene does not equal one RNA or protein. The genomic revolution has revealed numerous different RNA and protein molecules that can be produced from one gene, such as circular RNAs generated by back-splicing, proteins with residues mismatching the genomic encoding because of RNA editing, and proteins extended in the C terminus via stop codon readthrough in translation. Are these diverse products results of exquisite gene regulations or imprecise biological processes? While there are cases where the gene product diversity appears beneficial, genome-scale patterns suggest that much of this diversity arises from nonadaptive, molecular errors. This finding has important implications for studying the functions of diverse gene products and for understanding the fundamental properties and evolution of cellular life.
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Affiliation(s)
- Jianzhi Zhang
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA.
| | - Chuan Xu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200240, China
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34
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Bohleber S, Fradejas-Villar N, Zhao W, Reuter U, Schweizer U. High-Resolution Ribosome Profiling Reveals Gene-Specific Details of UGA Re-Coding in Selenoprotein Biosynthesis. Biomolecules 2022; 12:biom12101504. [PMID: 36291713 PMCID: PMC9599142 DOI: 10.3390/biom12101504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 10/11/2022] [Accepted: 10/14/2022] [Indexed: 11/16/2022] Open
Abstract
Co-translational incorporation of selenocysteine (Sec) into selenoproteins occurs at UGA codons in a process in which translational elongation competes with translational termination. Selenocysteine insertion sequence-binding protein 2 (SECISBP2) greatly enhances Sec incorporation into selenoproteins by interacting with the mRNA, ribosome, and elongation factor Sec (EFSEC). Ribosomal profiling allows to study the process of UGA re-coding in the physiological context of the cell and at the same time for all individual selenoproteins expressed in that cell. Using HAP1 cells expressing a mutant SECISBP2, we show here that high-resolution ribosomal profiling can be used to assess read-through efficiency at the UGA in all selenoproteins, including those with Sec close to the C-terminus. Analysis of ribosomes with UGA either at the A-site or the P-site revealed, in a transcript-specific manner, that SECISBP2 helps to recruit tRNASec and stabilize the mRNA. We propose to assess the effect of any perturbation of UGA read-through by determining the proportion of ribosomes carrying UGA in the P-site, pUGA. An additional, new observation is frameshifting that occurred 3′ of the UGA/Sec codon in SELENOF and SELENOW in SECISBP2-mutant HAP1 cells, a finding corroborated by reanalysis of neuron-specific Secisbp2R543Q-mutant brains.
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Affiliation(s)
- Simon Bohleber
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Noelia Fradejas-Villar
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Wenchao Zhao
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
- Department Medical Biochemistry and Biophysics, Karolinska Institute, SE-171 77 Stockholm, Sweden
| | - Uschi Reuter
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Universitätsklinikum Bonn, Rheinische Friedrich-Wilhelms-Universität Bonn, 53115 Bonn, Germany
- Correspondence: ; Tel.: +49-228-73-4444
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35
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Abstract
Protein expression with genetically encoded noncanonical amino acids (ncAAs) benefits a broad range of applications, from the discovery of biological therapeutics to fundamental biological studies. A major factor limiting the use of ncAAs is the lack of orthogonal translation systems (OTSs) that support efficient genetic code expansion at repurposed stop codons. Aminoacyl-tRNA synthetases (aaRSs) have been extensively evolved in Escherichia coli but are not always orthogonal in eukaryotes. In this work, we use a yeast display-based ncAA incorporation reporter platform with fluorescence-activated cell sorting to screen libraries of aaRSs in high throughput for (1) the incorporation of ncAAs not previously encoded in yeast; (2) the improvement of the performance of an existing aaRS; (3) highly selective OTSs capable of discriminating between closely related ncAA analogues; and (4) OTSs exhibiting enhanced polyspecificity to support translation with structurally diverse sets of ncAAs. The number of previously undiscovered aaRS variants we report in this work more than doubles the total number of translationally active aaRSs available for genetic code manipulation in yeast. The success of myriad screening strategies has important implications related to the fundamental properties and evolvability of aaRSs. Furthermore, access to OTSs with diverse activities and specific or polyspecific properties is invaluable for a range of applications within chemical biology, synthetic biology, and protein engineering.
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Affiliation(s)
- Jessica T Stieglitz
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
| | - James A Van Deventer
- Chemical and Biological Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
- Biomedical Engineering Department, Tufts University, Medford, Massachusetts 02155, United States
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36
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Noda Y, Okada S, Suzuki T. Regulation of A-to-I RNA editing and stop codon recoding to control selenoprotein expression during skeletal myogenesis. Nat Commun 2022; 13:2503. [PMID: 35523818 PMCID: PMC9076623 DOI: 10.1038/s41467-022-30181-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 04/05/2022] [Indexed: 12/13/2022] Open
Abstract
Selenoprotein N (SELENON), a selenocysteine (Sec)-containing protein with high reductive activity, maintains redox homeostasis, thereby contributing to skeletal muscle differentiation and function. Loss-of-function mutations in SELENON cause severe neuromuscular disorders. In the early-to-middle stage of myoblast differentiation, SELENON maintains redox homeostasis and modulates endoplasmic reticulum (ER) Ca2+ concentration, resulting in a gradual reduction from the middle-to-late stages due to unknown mechanisms. The present study describes post-transcriptional mechanisms that regulate SELENON expression during myoblast differentiation. Part of an Alu element in the second intron of SELENON pre-mRNA is frequently exonized during splicing, resulting in an aberrant mRNA that is degraded by nonsense-mediated mRNA decay (NMD). In the middle stage of myoblast differentiation, ADAR1-mediated A-to-I RNA editing occurs in the U1 snRNA binding site at 5' splice site, preventing Alu exonization and producing mature mRNA. In the middle-to-late stage of myoblast differentiation, the level of Sec-charged tRNASec decreases due to downregulation of essential recoding factors for Sec insertion, thereby generating a premature termination codon in SELENON mRNA, which is targeted by NMD.
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Affiliation(s)
- Yuta Noda
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Shunpei Okada
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
- Department of Microbiology, Faculty of Medicine, Shimane University, 89-1 Enyacho, Izumo, Shimane, 693-8501, Japan
| | - Tsutomu Suzuki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
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Abstract
PIWI-interacting RNAs (piRNAs) are small RNAs required to recognize and silence transposable elements. The 5' ends of mature piRNAs are defined through cleavage of long precursor transcripts, primarily by Zucchini (Zuc). Zuc-dependent cleavage typically occurs immediately upstream of a uridine. However, Zuc lacks sequence preference in vitro, pointing towards additional unknown specificity factors. Here, we examine murine piRNAs and reveal a strong and specific enrichment of three sequences (UAA, UAG, UGA)-corresponding to stop codons-at piRNA 5' ends. Stop codon sequences are also enriched immediately after piRNA processing intermediates, reflecting their Zuc-dependent tail-to-head arrangement. Further analyses reveal that a Zuc in vivo cleavage preference at four sequences (UAA, UAG, UGA, UAC) promotes 5' end stop codons. This observation is conserved across mammals and possibly further. Our work provides new insights into Zuc-dependent cleavage and may point to a previously unrecognized connection between piRNA biogenesis and the translational machinery.
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Affiliation(s)
- Susanne Bornelöv
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, CB2 0RE, UK.
| | - Benjamin Czech
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, CB2 0RE, UK
| | - Gregory J Hannon
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Cambridge, CB2 0RE, UK.
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38
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Joest EF, Winter C, Wesalo JS, Deiters A, Tampé R. Efficient Amber Suppression via Ribosomal Skipping for In Situ Synthesis of Photoconditional Nanobodies. ACS Synth Biol 2022; 11:1466-1476. [PMID: 35060375 PMCID: PMC9157392 DOI: 10.1021/acssynbio.1c00471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Genetic code expansion is a versatile method for in situ synthesis of modified proteins. During mRNA translation, amber stop codons are suppressed to site-specifically incorporate non-canonical amino acids. Thus, nanobodies can be equipped with photocaged amino acids to control target binding on demand. The efficiency of amber suppression and protein synthesis can vary with unpredictable background expression, and the reasons are hardly understood. Here, we identified a substantial limitation that prevented synthesis of nanobodies with N-terminal modifications for light control. After systematic analyses, we hypothesized that nanobody synthesis was severely affected by ribosomal inaccuracy during the early phases of translation. To circumvent a background-causing read-through of a premature stop codon, we designed a new suppression concept based on ribosomal skipping. As an example, we generated intrabodies with photoactivated target binding in mammalian cells. The findings provide valuable insights into the genetic code expansion and describe a versatile synthesis route for the generation of modified nanobodies that opens up new perspectives for efficient site-specific integration of chemical tools. In the area of photopharmacology, our flexible intrabody concept builds an ideal platform to modulate target protein function and interaction.
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Affiliation(s)
- Eike F Joest
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M, Germany
| | - Christian Winter
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M, Germany
| | - Joshua S Wesalo
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Alexander Deiters
- Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA
| | - Robert Tampé
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt/M, Germany
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39
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Gu YL, Sun CH, Liu P, Zhang X, Sinev AY, Dumont HJ, Han BP. Complete mitochondrial genome of Ovalona pulchella (Branchiopoda, Cladocera) as the first representative in the family Chydoridae: Gene rearrangements and phylogenetic analysis of Cladocera. Gene X 2022; 818:146230. [PMID: 35093448 DOI: 10.1016/j.gene.2022.146230] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/10/2021] [Accepted: 01/13/2022] [Indexed: 11/18/2022] Open
Abstract
Chydoridae are phytophilic-benthic microcrustaceans that make up a significant proportion of species diversity and play an important role in the littoral zone of freshwater ecosystems worldwide. Here, we provide the complete mitochondrial genome of Ovalona pulchella (King, 1853), determined by next-generation sequencing. The entire mitochondrial genome is 15,362 bp in length; this is the first sequenced mitochondrial genome in the family Chydoridae. The base composition and codon usage were typical of Cladocera species. The mitochondrial gene arrangement (37 genes) was not consistent with that of other Branchiopoda. Both maximum likelihood and Bayesian analyses supported each suborder and family of Branchiopoda as monophyletic groups. The relationships among the families were as follows: [(Leptestheriidae + Limnadiidae) + (Sididae + (Bosminidae + (Chydoridae + Daphniidae)))] + Triopsidae. The newly sequenced O. pulchella was most closely related to the family Daphniidae. The complete mitochondrial genome of O. pulchella also provides valuable molecular information for further analysis of the phylogeny of the Chydoridae and the taxonomic status of the Branchiopoda.
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Affiliation(s)
- Yang-Liang Gu
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, China; South China Institute of Environmental Sciences, Ministry of Ecology and Environment of the People's Republic of China, Guangzhou 510530, China
| | - Cheng-He Sun
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, China.
| | - Ping Liu
- College of Environmental Science and Engineering, Yangzhou University, Jiangsu 225127, China.
| | - Xiaoli Zhang
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Artem Y Sinev
- Department of Invertebrate Zoology, Biological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119991, Russia
| | - Henri J Dumont
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
| | - Bo-Ping Han
- Department of Ecology and Institute of Hydrobiology, Jinan University, Guangzhou 510632, China
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40
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Wu Y, He Y, Sretenovic S, Liu S, Cheng Y, Han Y, Liu G, Bao Y, Fang Q, Zheng X, Zhou J, Qi Y, Zhang Y, Zhang T. CRISPR-BETS: a base-editing design tool for generating stop codons. Plant Biotechnol J 2022; 20:499-510. [PMID: 34669232 PMCID: PMC8882796 DOI: 10.1111/pbi.13732] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 10/17/2021] [Indexed: 06/12/2023]
Abstract
Cytosine base editors (CBEs) can install a predefined stop codon at the target site, representing a more predictable and neater method for creating genetic knockouts without altering the genome size. Due to the enhanced predictability of the editing outcomes, it is also more efficient to obtain homozygous mutants in the first generation. With the recent advancement of CBEs on improved editing activity, purify and specificity in plants and animals, base editing has become a more appealing technology for generating knockouts. However, there is a lack of design tools that can aid the adoption of CBEs for achieving such a purpose, especially in plants. Here, we developed a user-friendly design tool named CRISPR-BETS (base editing to stop), which helps with guide RNA (gRNA) design for introducing stop codons in the protein-coding genes of interest. We demonstrated in rice and tomato that CRISPR-BETS is easy-to-use, and its generated gRNAs are highly specific and efficient for generating stop codons and obtaining homozygous knockout lines. While we tailored the tool for the plant research community, CRISPR-BETS can also serve non-plant species.
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Affiliation(s)
- Yuechao Wu
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Jiangsu Co‐Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhouChina
| | - Yao He
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Simon Sretenovic
- Department of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMarylandUSA
| | - Shishi Liu
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Yanhao Cheng
- Department of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMarylandUSA
| | - Yangshuo Han
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Jiangsu Co‐Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhouChina
| | - Guanqing Liu
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Jiangsu Co‐Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhouChina
| | - Yu Bao
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Jiangsu Co‐Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhouChina
| | - Qing Fang
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Xuelian Zheng
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Jianping Zhou
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Yiping Qi
- Department of Plant Science and Landscape ArchitectureUniversity of MarylandCollege ParkMarylandUSA
- Institute for Bioscience and Biotechnology ResearchUniversity of MarylandRockvilleMarylandUSA
| | - Yong Zhang
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Department of BiotechnologySchool of Life Science and TechnologyCenter for Informational BiologyUniversity of Electronic Science and Technology of ChinaChengduChina
| | - Tao Zhang
- Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding/Jiangsu Key Laboratory of Crop Genetics and PhysiologyAgricultural College of Yangzhou UniversityYangzhouChina
- Jiangsu Co‐Innovation Center for Modern Production Technology of Grain CropsYangzhou UniversityYangzhouChina
- Key Laboratory of Plant Functional Genomics of the Ministry of Education/Joint International Research Laboratory of Agriculture and Agri‐Product SafetyThe Ministry of Education of ChinaYangzhou UniversityYangzhouChina
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41
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Kim S, Kim JA, Kang H, Kim DH. A premature stop codon in BrFLC2 transcript results in early flowering in oilseed-type Brassica rapa plants. Plant Mol Biol 2022; 108:241-255. [PMID: 35064421 DOI: 10.1007/s11103-021-01231-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 12/05/2021] [Indexed: 06/14/2023]
Abstract
Nonsense-mediated mRNA decay (NMD)-mediated degradation of BrFLC2 transcripts is the main cause of rapid flowering of oilseed-type B. rapa 'LP08' plants. Many Brassica species require vernalization (long-term winter-like cooling) for transition to the reproductive stage. In the past several decades, scientific efforts have been made to discern the molecular mechanisms underlying vernalization in many species. Thus, to identify the key regulators required for vernalization in Brassica rapa L., we constructed a linkage map composed of 7833 single nucleotide polymorphism markers using the late-flowering Chinese cabbage (B. rapa L. ssp. pekinensis) inbred line 'Chiifu' and the early-flowering yellow sarson (B. rapa L. ssp. trilocularis) line 'LP08' and identified a single major QTL on the upper-arm of the chromosome A02. In addition, we compared the transcriptomes of the lines 'Chiifu' and 'LP08' at five vernalization time points, including both non-vernalized and post-vernalization conditions. We observed that BrFLC2 was significantly downregulated in the early flowering 'LP08' and had two deletion sites (one at 4th exon and the other at 3' downstream region) around the BrFLC2 genomic region compared with the BrFLC2 genomic region in 'Chiifu'. Large deletion at 3' downstream region did not significantly affect transcription of both sense BrFLC2 transcript and antisense transcript, BrFLC2as along vernalization time course. However, the other deletion at 4th exon of BrFLC2 resulted in the generation of premature stop codon in BrFLC2 transcript in LP08 line. Cycloheximide treatment of LP08 line showed the de-repressed level of BrFLC2 in LP08, suggesting that low transcript level of BrFLC2 in LP08 might be caused by nonsense-mediated mRNA decay removing the nonsense transcript of BrFLC2. Collectively, this study provides a better understanding of the molecular mechanisms underlying floral transition in B. rapa.
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Affiliation(s)
- Sujeong Kim
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Jin A Kim
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, South Korea
| | - Hajeong Kang
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea
| | - Dong-Hwan Kim
- Department of Plant Science and Technology, Chung-Ang University, Anseong, South Korea.
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42
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Lackey L, Coria A, Ghosh AJ, Grayeski P, Hatfield A, Shankar V, Platig J, Xu Z, Ramos SBV, Silverman EK, Ortega VE, Cho MH, Hersh CP, Hobbs BD, Castaldi P, Laederach A. Alternative poly-adenylation modulates α1-antitrypsin expression in chronic obstructive pulmonary disease. PLoS Genet 2021; 17:e1009912. [PMID: 34784346 PMCID: PMC8631626 DOI: 10.1371/journal.pgen.1009912] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 11/30/2021] [Accepted: 10/25/2021] [Indexed: 01/07/2023] Open
Abstract
α1-anti-trypsin (A1AT), encoded by SERPINA1, is a neutrophil elastase inhibitor that controls the inflammatory response in the lung. Severe A1AT deficiency increases risk for Chronic Obstructive Pulmonary Disease (COPD), however, the role of A1AT in COPD in non-deficient individuals is not well known. We identify a 2.1-fold increase (p = 2.5x10-6) in the use of a distal poly-adenylation site in primary lung tissue RNA-seq in 82 COPD cases when compared to 64 controls and replicate this in an independent study of 376 COPD and 267 controls. This alternative polyadenylation event involves two sites, a proximal and distal site, 61 and 1683 nucleotides downstream of the A1AT stop codon. To characterize this event, we measured the distal ratio in human primary tissue short read RNA-seq data and corroborated our results with long read RNA-seq data. Integrating these results with 3' end RNA-seq and nanoluciferase reporter assay experiments we show that use of the distal site yields mRNA transcripts with over 50-fold decreased translation efficiency and A1AT expression. We identified seven RNA binding proteins using enhanced CrossLinking and ImmunoPrecipitation precipitation (eCLIP) with one or more binding sites in the SERPINA1 3' UTR. We combined these data with measurements of the distal ratio in shRNA knockdown experiments, nuclear and cytoplasmic fractionation, and chemical RNA structure probing. We identify Quaking Homolog (QKI) as a modulator of SERPINA1 mRNA translation and confirm the role of QKI in SERPINA1 translation with luciferase reporter assays. Analysis of single-cell RNA-seq showed differences in the distribution of the SERPINA1 distal ratio among hepatocytes, macrophages, αβ-Tcells and plasma cells in the liver. Alveolar Type 1,2, dendritic cells and macrophages also vary in their distal ratio in the lung. Our work reveals a complex post-transcriptional mechanism that regulates alternative polyadenylation and A1AT expression in COPD.
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Affiliation(s)
- Lela Lackey
- Department of Genetics and Biochemistry, Center for Human Genetics, Clemson University, Greenwood, South Carolina, United States of America
- * E-mail: (LL); (AL)
| | - Aaztli Coria
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Auyon J. Ghosh
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Phil Grayeski
- Curriculum in Genetics and Molecular Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Abigail Hatfield
- Department of Genetics and Biochemistry, Center for Human Genetics, Clemson University, Greenwood, South Carolina, United States of America
| | - Vijay Shankar
- Department of Genetics and Biochemistry, Center for Human Genetics, Clemson University, Greenwood, South Carolina, United States of America
| | - John Platig
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Zhonghui Xu
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Silvia B. V. Ramos
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Edwin K. Silverman
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Victor E. Ortega
- Department of Internal Medicine, Division of Respiratory Medicine, Center for Individualized Medicine, Mayo Clinic, Scottsdale, Arizona, United States of America
| | - Michael H. Cho
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Craig P. Hersh
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Brian D. Hobbs
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Pulmonary and Critical Care Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Peter Castaldi
- Channing Division of Network Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- Division of Internal Medicine and Primary Care, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Alain Laederach
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
- * E-mail: (LL); (AL)
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Abstract
Noncanonical amino acid mutagenesis has emerged as a powerful tool for the study of protein structure and function. While triplet nonsense codons, especially the amber codon, have been widely employed, quadruplet codons have attracted attention for the potential of creating additional blank codons for noncanonical amino acids mutagenesis. In this review, we discuss methodologies and applications of quadruplet codon decoding in genetic code expansion both in vitro and in vivo.
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Affiliation(s)
- Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, United States; The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States.
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, United States; The Nebraska Center for Integrated Biomolecular Communication (NCIBC), University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
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44
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Zinshteyn B, Sinha NK, Enam SU, Koleske B, Green R. Translational repression of NMD targets by GIGYF2 and EIF4E2. PLoS Genet 2021; 17:e1009813. [PMID: 34665823 PMCID: PMC8555832 DOI: 10.1371/journal.pgen.1009813] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 10/29/2021] [Accepted: 09/08/2021] [Indexed: 12/26/2022] Open
Abstract
Translation of messenger RNAs (mRNAs) with premature termination codons produces truncated proteins with potentially deleterious effects. This is prevented by nonsense-mediated mRNA decay (NMD) of these mRNAs. NMD is triggered by ribosomes terminating upstream of a splice site marked by an exon-junction complex (EJC), but also acts on many mRNAs lacking a splice junction after their termination codon. We developed a genome-wide CRISPR flow cytometry screen to identify regulators of mRNAs with premature termination codons in K562 cells. This screen recovered essentially all core NMD factors and suggested a role for EJC factors in degradation of PTCs without downstream splicing. Among the strongest hits were the translational repressors GIGYF2 and EIF4E2. GIGYF2 and EIF4E2 mediate translational repression but not mRNA decay of a subset of NMD targets and interact with NMD factors genetically and physically. Our results suggest a model wherein recognition of a stop codon as premature can lead to its translational repression through GIGYF2 and EIF4E2.
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Affiliation(s)
- Boris Zinshteyn
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Niladri K. Sinha
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Syed Usman Enam
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Benjamin Koleske
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
| | - Rachel Green
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
- Howard Hughes Medical Institute, Chevy Chase, Maryland, United States of America
- * E-mail:
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45
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Bhandari BK, Lim CS, Remus DM, Chen A, van Dolleweerd C, Gardner PP. Analysis of 11,430 recombinant protein production experiments reveals that protein yield is tunable by synonymous codon changes of translation initiation sites. PLoS Comput Biol 2021; 17:e1009461. [PMID: 34610008 PMCID: PMC8519471 DOI: 10.1371/journal.pcbi.1009461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 10/15/2021] [Accepted: 09/19/2021] [Indexed: 12/16/2022] Open
Abstract
Recombinant protein production is a key process in generating proteins of interest in the pharmaceutical industry and biomedical research. However, about 50% of recombinant proteins fail to be expressed in a variety of host cells. Here we show that the accessibility of translation initiation sites modelled using the mRNA base-unpairing across the Boltzmann's ensemble significantly outperforms alternative features. This approach accurately predicts the successes or failures of expression experiments, which utilised Escherichia coli cells to express 11,430 recombinant proteins from over 189 diverse species. On this basis, we develop TIsigner that uses simulated annealing to modify up to the first nine codons of mRNAs with synonymous substitutions. We show that accessibility captures the key propensity beyond the target region (initiation sites in this case), as a modest number of synonymous changes is sufficient to tune the recombinant protein expression levels. We build a stochastic simulation model and show that higher accessibility leads to higher protein production and slower cell growth, supporting the idea of protein cost, where cell growth is constrained by protein circuits during overexpression.
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Affiliation(s)
- Bikash K. Bhandari
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Chun Shen Lim
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Daniela M. Remus
- Callaghan Innovation Protein Science and Engineering, University of Canterbury, Christchurch, New Zealand
| | - Augustine Chen
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Craig van Dolleweerd
- Biomolecular Interaction Center, University of Canterbury, Christchurch, New Zealand
| | - Paul P. Gardner
- Department of Biochemistry, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
- Biomolecular Interaction Center, University of Canterbury, Christchurch, New Zealand
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46
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Napthine S, Hill CH, Nugent HCM, Brierley I. Modulation of Viral Programmed Ribosomal Frameshifting and Stop Codon Readthrough by the Host Restriction Factor Shiftless. Viruses 2021; 13:v13071230. [PMID: 34202160 PMCID: PMC8310280 DOI: 10.3390/v13071230] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/15/2021] [Accepted: 06/19/2021] [Indexed: 12/18/2022] Open
Abstract
The product of the interferon-stimulated gene C19orf66, Shiftless (SHFL), restricts human immunodeficiency virus replication through downregulation of the efficiency of the viral gag/pol frameshifting signal. In this study, we demonstrate that bacterially expressed, purified SHFL can decrease the efficiency of programmed ribosomal frameshifting in vitro at a variety of sites, including the RNA pseudoknot-dependent signals of the coronaviruses IBV, SARS-CoV and SARS-CoV-2, and the protein-dependent stimulators of the cardioviruses EMCV and TMEV. SHFL also reduced the efficiency of stop-codon readthrough at the murine leukemia virus gag/pol signal. Using size-exclusion chromatography, we confirm the binding of the purified protein to mammalian ribosomes in vitro. Finally, through electrophoretic mobility shift assays and mutational analysis, we show that expressed SHFL has strong RNA binding activity that is necessary for full activity in the inhibition of frameshifting, but shows no clear specificity for stimulatory RNA structures.
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Affiliation(s)
| | | | | | - Ian Brierley
- Correspondence: ; Tel.: +44-12-2333-6914; Fax: +44-12-2333-6926
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47
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Zhang Y, Pelechano V. High-throughput 5'P sequencing enables the study of degradation-associated ribosome stalls. Cell Rep Methods 2021; 1:100001. [PMID: 35474692 PMCID: PMC9017187 DOI: 10.1016/j.crmeth.2021.100001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/01/2021] [Accepted: 02/26/2021] [Indexed: 12/21/2022]
Abstract
RNA degradation is critical for gene expression and mRNA quality control. mRNA degradation is connected to the translation process up to the degree that 5'-3' mRNA degradation follows the last translating ribosome. Here, we present an improved high-throughput 5'P degradome RNA-sequencing method (HT-5Pseq). HT-5Pseq is easy, scalable, and uses affordable duplex-specific nuclease-based rRNA depletion. We investigate in vivo ribosome stalls focusing on translation termination. By comparing ribosome stalls identified by ribosome profiling, disome-seq and HT-5Pseq, we find that degradation-associated ribosome stalls are often enriched in Arg preceding the stop codon. On the contrary, mRNAs depleted for those stalls use more frequently a TAA stop codon preceded by hydrophobic amino acids. Finally, we show that termination stalls found by HT-5Pseq, and not by other approaches, are associated with decreased mRNA stability. Our work suggests that ribosome stalls associated with mRNA decay can be easily captured by investigating the 5'P degradome.
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Affiliation(s)
- Yujie Zhang
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna 171 65, Sweden
| | - Vicent Pelechano
- SciLifeLab, Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Solna 171 65, Sweden
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48
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Mangkalaphiban K, He F, Ganesan R, Wu C, Baker R, Jacobson A. Transcriptome-wide investigation of stop codon readthrough in Saccharomyces cerevisiae. PLoS Genet 2021; 17:e1009538. [PMID: 33878104 PMCID: PMC8087045 DOI: 10.1371/journal.pgen.1009538] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 04/30/2021] [Accepted: 04/06/2021] [Indexed: 11/18/2022] Open
Abstract
Translation of mRNA into a polypeptide is terminated when the release factor eRF1 recognizes a UAA, UAG, or UGA stop codon in the ribosomal A site and stimulates nascent peptide release. However, stop codon readthrough can occur when a near-cognate tRNA outcompetes eRF1 in decoding the stop codon, resulting in the continuation of the elongation phase of protein synthesis. At the end of a conventional mRNA coding region, readthrough allows translation into the mRNA 3'-UTR. Previous studies with reporter systems have shown that the efficiency of termination or readthrough is modulated by cis-acting elements other than stop codon identity, including two nucleotides 5' of the stop codon, six nucleotides 3' of the stop codon in the ribosomal mRNA channel, and stem-loop structures in the mRNA 3'-UTR. It is unknown whether these elements are important at a genome-wide level and whether other mRNA features proximal to the stop codon significantly affect termination and readthrough efficiencies in vivo. Accordingly, we carried out ribosome profiling analyses of yeast cells expressing wild-type or temperature-sensitive eRF1 and developed bioinformatics strategies to calculate readthrough efficiency, and to identify mRNA and peptide features which influence that efficiency. We found that the stop codon (nt +1 to +3), the nucleotide after it (nt +4), the codon in the P site (nt -3 to -1), and 3'-UTR length are the most influential features in the control of readthrough efficiency, while nts +5 to +9 had milder effects. Additionally, we found low readthrough genes to have shorter 3'-UTRs compared to high readthrough genes in cells with thermally inactivated eRF1, while this trend was reversed in wild-type cells. Together, our results demonstrated the general roles of known regulatory elements in genome-wide regulation and identified several new mRNA or peptide features affecting the efficiency of translation termination and readthrough.
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Affiliation(s)
- Kotchaphorn Mangkalaphiban
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Feng He
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Robin Ganesan
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Chan Wu
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Richard Baker
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Allan Jacobson
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
- * E-mail:
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49
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Belinky F, Ganguly I, Poliakov E, Yurchenko V, Rogozin IB. Analysis of Stop Codons within Prokaryotic Protein-Coding Genes Suggests Frequent Readthrough Events. Int J Mol Sci 2021; 22:ijms22041876. [PMID: 33672790 PMCID: PMC7918605 DOI: 10.3390/ijms22041876] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 02/07/2023] Open
Abstract
Nonsense mutations turn a coding (sense) codon into an in-frame stop codon that is assumed to result in a truncated protein product. Thus, nonsense substitutions are the hallmark of pseudogenes and are used to identify them. Here we show that in-frame stop codons within bacterial protein-coding genes are widespread. Their evolutionary conservation suggests that many of them are not pseudogenes, since they maintain dN/dS values (ratios of substitution rates at non-synonymous and synonymous sites) significantly lower than 1 (this is a signature of purifying selection in protein-coding regions). We also found that double substitutions in codons—where an intermediate step is a nonsense substitution—show a higher rate of evolution compared to null models, indicating that a stop codon was introduced and then changed back to sense via positive selection. This further supports the notion that nonsense substitutions in bacteria are relatively common and do not necessarily cause pseudogenization. In-frame stop codons may be an important mechanism of regulation: Such codons are likely to cause a substantial decrease of protein expression levels.
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Affiliation(s)
- Frida Belinky
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (F.B.); (I.G.)
| | - Ishan Ganguly
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (F.B.); (I.G.)
| | - Eugenia Poliakov
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Vyacheslav Yurchenko
- Life Science Research Centre, Faculty of Science, University of Ostrava, 710 00 Ostrava, Czech Republic
- Martsinovsky Institute of Medical Parasitology, Tropical and Vector Borne Diseases, Sechenov University, 119435 Moscow, Russia
- Correspondence: (V.Y.); (I.B.R.)
| | - Igor B. Rogozin
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA; (F.B.); (I.G.)
- Correspondence: (V.Y.); (I.B.R.)
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50
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Kawakita T, Mukai T, Yoshida M, Yamada H, Nakayama M, Miyamoto Y, Suzuki M, Nakata N, Takii T, Ryo A, Ohara N, Ato M. Point mutation in the stop codon of MAV_RS14660 increases the growth rate of Mycobacterium avium subspecies hominissuis. Microbiology (Reading) 2021; 167:001007. [PMID: 33357282 PMCID: PMC8131024 DOI: 10.1099/mic.0.001007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 11/30/2020] [Indexed: 11/18/2022]
Abstract
Mycobacterium avium subspecies hominissuis (MAH) is a pathogen that causes various non-tuberculous mycobacterial diseases in humans and animals worldwide. Among the genus, MAH is characterized by relatively slow growth. Here, we isolated a rapidly growing variant of the MAH 104 strain. The variant strain (named N104) exhibited an enhanced growth rate and higher motility compared to the parent MAH 104 strain (P104). Whole-genome sequencing analysis of N104 revealed the loss of the stop codon of MAV_RS14660 due to a single nucleotide replacement, resulting in the substitution of the codon for tryptophan. Notably, exclusion of the stop codon ligated the open reading frames and caused the fusion of two adjacent proteins. A revertant parent strain, in which a mutation was introduced to restore the stop codon, revealed that elimination of the stop codon in MAV_RS14660 was responsible for the N104 phenotype. Furthermore, we analysed the phenotypes of the parent and mutated strains by determining the functions of the MAV_RS14660 and MAV_RS14655 coding regions flanking the stop codon. The mutant strains, expected to express a fusion protein, exhibited increased resistance to antimicrobial drugs and exogenous copper toxicity compared to that of the parent strains. These findings suggest that the fusion of the MAV_RS14660- and MAV_RS14655-encoding regions in the mutant N104 strain could be related to the modified functions of these intrinsic proteins.
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Affiliation(s)
- Tomomi Kawakita
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
- Department of Microbiology and Molecular Biodefense Research, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tetsu Mukai
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Mitsunori Yoshida
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Hiroyuki Yamada
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Tokyo, Japan
| | - Masaaki Nakayama
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan
| | - Yuji Miyamoto
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Masato Suzuki
- Antimicrobial Resistance Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Noboru Nakata
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
| | - Takemasa Takii
- Department of Mycobacterium Reference and Research, Research Institute of Tuberculosis, Tokyo, Japan
| | - Akihide Ryo
- Department of Microbiology and Molecular Biodefense Research, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Naoya Ohara
- Department of Oral Microbiology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan
- Advanced Research Center for Oral and Craniofacial Sciences, Okayama University Dental School, Okayama, Japan
| | - Manabu Ato
- Department of Mycobacteriology, Leprosy Research Center, National Institute of Infectious Diseases, Tokyo, Japan
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