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Lamolle G, Iriarte A, Musto H. Codon usage in the flatworm Schistosoma mansoni is shaped by the mutational bias towards A+T and translational selection, which increases GC-ending codons in highly expressed genes. Mol Biochem Parasitol 2021; 247:111445. [PMID: 34942292 DOI: 10.1016/j.molbiopara.2021.111445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 12/14/2021] [Accepted: 12/17/2021] [Indexed: 11/30/2022]
Abstract
Schistosoma mansoni is a trematode flatworm that parasitizes humans and produces a disease called bilharzia. At the genomic level, it is characterized by a low genomic GC content and an "isochore-like" structure, where GC-richest regions, mainly placed at the extremes of the chromosomes, are interspersed with low GC-regions. Furthermore, the GC-richest regions are at the same time the gene-richest, and where the most heavily expressed genes are placed. Taking these features into account, we decided to reanalyze the codon usage of this flatworm. Our results show that a) when all genes are considered together, the strong mutational bias towards A + T leads to a predominance of A/T-ending codons, b) a multivariate analysis discriminates between highly and lowly expressed genes, c) the sequences expressed at highest levels display a significant increase in G/C-ending codons, d) when comparing the molecular distances with a closely related species the synonymous distance in highly expressed genes is significantly lower than in lowly expressed sequences. Therefore, we conclude that despite previous results, which were performed with a small sample of genes, codon usage in S. mansoni is the result of two forces that operate in opposite directions: while mutational bias leads to a predominance of A/T codons, translational selection, working at the level of speed, increment G/C ending triplets.
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Affiliation(s)
- Guillermo Lamolle
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Avenida A. Navarro 3051, 11600 Montevideo, Uruguay.
| | - Héctor Musto
- Unidad de Genómica Evolutiva, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400 Montevideo, Uruguay.
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2
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Abstract
The resistance markers could ensure the entry of the CRISPR/Cas9 system into Aspergillus niger cells instead of gene editing. To increase the efficiency of positive colony screening on the primary transformation plates, we designed a visualized multigene editing system (VMS) via a unique tRNA-guide RNA (gRNA) array containing the gRNAs of a pigment gene albA and target genes. Disruption of albA produces white colonies, and the sequences of the endogenous tRNAAla, tRNAPhe, tRNAArg, tRNAIle, and tRNALeu enhance gRNA release. The disruption efficiencies of multigene were analyzed in the A. niger strain AG11 using ammA, amyA, prtT, kusA, and glaA as reporters. In white colonies on the primary transformation plates, the disruption rates of one-, two-, three-, four-, and five-target genes reached 89.2, 70.91, 50, 22.41, and 4.17%, respectively. The VMS developed here provides an effective method for screening homokaryotic multigene editing strains of A. niger.
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Affiliation(s)
- Cen Li
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shengqi Rao
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 214122, China
| | - Guocheng Du
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Song Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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Gupta S, Singh R. Comparative study of codon usage profiles of Zingiber officinale and its associated fungal pathogens. Mol Genet Genomics 2021; 296:1121-1134. [PMID: 34181071 DOI: 10.1007/s00438-021-01808-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/22/2021] [Indexed: 01/08/2023]
Abstract
Codon usage bias influences the genetic features prevalent in genomes of all the organisms. It also plays a crucial role in establishing the host-pathogen relationship. The present study elucidates the role of codon usage pattern regarding the predilection of fungal pathogens Aspergillus flavus, Aspergillus niger, Fusarium oxysporum and Colletotrichum gloeosporioides towards host plant Zingiber officinale. We found a similar trend of codon usage pattern operative in plant and fungal pathogens. This concurrence might be attributed for the colonization of fungal pathogens in Z. officinale. The transcriptome of both plant and pathogens showed bias towards GC-ending codons. Natural selection and mutational pressure seem to be accountable for shaping the codon usage pattern of host and pathogen. We also identified some distinctive preferred codons in A. flavus, F. oxysporum and Z. officinale that could be regarded as signature codons for the identification of these organisms. Knowledge of favored, avoided and unique codons will help to devise strategies for reducing spice losses due to fungal pathogens.
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Affiliation(s)
- Suruchi Gupta
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, 180001, India
| | - Ravail Singh
- Plant Biotechnology Division, CSIR-Indian Institute of Integrative Medicine, Jammu, 180001, India.
- Academy of Scientific and Innovative Research (AcSIR), Jammu, 180001, India.
- DZMB Senckenberg am Meer, Wilhelmshaven, Germany.
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Kim HS, Kim JE, Hwangbo A, Akerboom J, Looger LL, Duncan R, Son H, Czymmek KJ, Kang S. Evaluation of multi-color genetically encoded Ca 2+ indicators in filamentous fungi. Fungal Genet Biol 2021; 149:103540. [PMID: 33607281 DOI: 10.1016/j.fgb.2021.103540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 01/27/2021] [Accepted: 01/30/2021] [Indexed: 11/18/2022]
Abstract
Genetically encoded Ca2+ indicators (GECIs) enable long-term monitoring of cellular and subcellular dynamics of this second messenger in response to environmental and developmental cues without relying on exogenous dyes. Continued development and optimization in GECIs, combined with advances in gene manipulation, offer new opportunities for investigating the mechanism of Ca2+ signaling in fungi, ranging from documenting Ca2+ signatures under diverse conditions and genetic backgrounds to evaluating how changes in Ca2+ signature impact calcium-binding proteins and subsequent cellular changes. Here, we attempted to express multi-color (green, yellow, blue, cyan, and red) circularly permuted fluorescent protein (FP)-based Ca2+ indicators driven by multiple fungal promoters in Fusarium oxysporum, F. graminearum, and Neurospora crassa. Several variants were successfully expressed, with GCaMP5G driven by the Magnaporthe oryzae ribosomal protein 27 and F. verticillioides elongation factor-1α gene promoters being optimal for F. graminearum and F. oxysporum, respectively. Transformants expressing GCaMP5G were compared with those expressing YC3.60, a ratiometric Cameleon Ca2+ indicator. Wild-type and three Ca2+ signaling mutants of F. graminearum expressing GCaMP5G exhibited improved signal-to-noise and increased temporal and spatial resolution and are also more amenable to studies involving multiple FPs compared to strains expressing YC3.60.
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Affiliation(s)
- Hye-Seon Kim
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States; Delaware Biotechnology Institute, Newark, DE 19711, United States
| | - Jung-Eun Kim
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, United States
| | - Aram Hwangbo
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Jasper Akerboom
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, United States
| | - Loren L Looger
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, United States
| | - Randall Duncan
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States
| | - Hokyoung Son
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, Republic of Korea
| | - Kirk J Czymmek
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, United States; Delaware Biotechnology Institute, Newark, DE 19711, United States; Donald Danforth Plant Science Center, Saint Louis, MO 63132, United States.
| | - Seogchan Kang
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802, United States.
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Gupta S, Paul K, Roy A. Codon usage signatures in the genus Cryptococcus: A complex interplay of gene expression, translational selection and compositional bias. Genomics 2020; 113:821-830. [PMID: 33096254 DOI: 10.1016/j.ygeno.2020.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 09/16/2020] [Accepted: 10/05/2020] [Indexed: 11/30/2022]
Abstract
The fungal genus Cryptococcus comprises of several diverse species. The pathogens forming Cryptococcus neoformans/ Cryptococcus gatti species complex are of immense clinical significance owing to the high frequency of infections and deaths globally. Three closely related non-pathogenic species namely, Cryptococcus amylolentus, Cryptococcus wingfieldii and Cryptococcus depauperatus are the non-pathogenic ancestral species from which pathogenic lineages have diverged. In the current study, a comprehensive analysis of factors influencing the codon and amino acid usage bias in six pathogenic and three non-pathogenic species was performed. Our results revealed that though compositional bias played a crucial role, translational selection and gene expression were the key determinants of codon usage variations. Analysis of relative dinucleotide abundance and codon context signatures revealed strict avoidance of TpA dinucleotide across genomes. Multivariate statistical analysis based on codon usage data resulted in discrete clustering of pathogens and non-pathogens which correlated with previous reports on their phylogenetic distribution.
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Affiliation(s)
- Shelly Gupta
- Department of Biochemistry, School of Bioengineering and Biosciences, Lovely Professional University, Punjab 144411, India.
| | - Karan Paul
- Department of Biochemistry, DAV University, Jalandhar, Punjab 144001, India
| | - Ayan Roy
- Department of Biotechnology, School of Bioengineering and Biosciences, Lovely Professional University, Punjab 144411, India.
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Sanguinetti M, Iriarte A, Amillis S, Marín M, Musto H, Ramón A. A pair of non-optimal codons are necessary for the correct biosynthesis of the Aspergillus nidulans urea transporter, UreA. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190773. [PMID: 31827830 PMCID: PMC6894576 DOI: 10.1098/rsos.190773] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
In both prokaryotic and eukaryotic genomes, synonymous codons are unevenly used. Such differential usage of optimal or non-optimal codons has been suggested to play a role in the control of translation initiation and elongation, as well as at the level of transcription and mRNA stability. In the case of membrane proteins, codon usage has been proposed to assist in the establishment of a pause necessary for the correct targeting of the nascent chains to the translocon. By using as a model UreA, the Aspergillus nidulans urea transporter, we revealed that a pair of non-optimal codons encoding amino acids situated at the boundary between the N-terminus and the first transmembrane segment are necessary for proper biogenesis of the protein at 37°C. These codons presumably regulate the translation rate in a previously undescribed fashion, possibly contributing to the correct interaction of ureA-translating ribosome-nascent chain complexes with the signal recognition particle and/or other factors, while the polypeptide has not yet emerged from the ribosomal tunnel. Our results suggest that the presence of the pair of non-optimal codons would not be functionally important in all cellular conditions. Whether this mechanism would affect other proteins remains to be determined.
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Affiliation(s)
- Manuel Sanguinetti
- Sección Bioquímica, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Andrés Iriarte
- Laboratorio de Biología Computacional, Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, UdelaR, Montevideo, Uruguay
- Laboratorio de Organización y Evolución del Genoma, Unidad de Genómica Evolutiva, Departamento de Evolución, Facultad de Ciencias, UdelaR, Montevideo, Uruguay
| | - Sotiris Amillis
- Department of Biology, National and Kapodistrian University of Athens, Athens, Hellas, Greece
| | - Mónica Marín
- Sección Bioquímica, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Héctor Musto
- Laboratorio de Organización y Evolución del Genoma, Unidad de Genómica Evolutiva, Departamento de Evolución, Facultad de Ciencias, UdelaR, Montevideo, Uruguay
| | - Ana Ramón
- Sección Bioquímica, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República (UdelaR), Montevideo, Uruguay
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7
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Comprehensive profiling of codon usage signatures and codon context variations in the genus Ustilago. World J Microbiol Biotechnol 2019; 35:118. [DOI: 10.1007/s11274-019-2693-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 07/07/2019] [Indexed: 02/02/2023]
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8
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Roy A, van Staden J. Insights into the riddles of codon usage patterns and codon context signatures in fungal genus
Puccinia
, a persistent threat to global agriculture. J Cell Biochem 2019; 120:19555-19566. [DOI: 10.1002/jcb.29263] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Accepted: 06/06/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Ayan Roy
- Research Centre for Plant Growth and Development School of Life Sciences, University of KwaZulu‐Natal Pietermaritzburg South Africa
| | - Johannes van Staden
- Research Centre for Plant Growth and Development School of Life Sciences, University of KwaZulu‐Natal Pietermaritzburg South Africa
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Song H, Liu J, Song Q, Zhang Q, Tian P, Nan Z. Comprehensive Analysis of Codon Usage Bias in Seven Epichloë Species and Their Peramine-Coding Genes. Front Microbiol 2017; 8:1419. [PMID: 28798739 PMCID: PMC5529348 DOI: 10.3389/fmicb.2017.01419] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Accepted: 07/13/2017] [Indexed: 11/22/2022] Open
Abstract
Codon usage bias plays an important role in shaping genomes and genes in unicellular species and multicellular species. Here, we first analyzed codon usage bias in seven Epichloë species and their peramine-coding genes. Our results showed that both natural selection and mutation pressure played a role in forming codon usage bias in seven Epichloë species. All seven Epichloë species contained a peramine-coding gene cluster. Interestingly, codon usage bias of peramine-coding genes were not affected by natural selection or mutation pressure. There were 13 codons more frequently found in Epichloë genome sequences, peramine-coding gene clusters and orthologous peramine-coding genes, all of which had a bias to end with a C nucleotide. In the seven genomes analyzed, codon usage was biased in highly expressed coding sequences (CDSs) with shorter length and higher GC content. Genes in the peramine-coding gene cluster had higher GC content at the third nucleotide position of the codon, and highly expressed genes had higher GC content at the second position. In orthologous peramine-coding CDSs, high expression level was not significantly correlated with CDS length and GC content. Analysis of selection pressure identified that the genes orthologous to peramine genes were under purifying selection. There were no differences in codon usage bias and selection pressure between peramine product genes and non-functional peramine product genes. Our results provide insights into understanding codon evolution in Epichloë species.
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Affiliation(s)
- Hui Song
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
| | - Jing Liu
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
| | - Qiuyan Song
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
| | - Qingping Zhang
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
| | - Pei Tian
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
| | - Zhibiao Nan
- State Key Laboratory of Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou UniversityLanzhou, China
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Arnold SL, Panaccione DG. Biosynthesis of the Pharmaceutically Important Fungal Ergot Alkaloid Dihydrolysergic Acid Requires a Specialized Allele of cloA. Appl Environ Microbiol 2017; 83:e00805-17. [PMID: 28476772 PMCID: PMC5494617 DOI: 10.1128/aem.00805-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/03/2017] [Indexed: 11/20/2022] Open
Abstract
Ergot alkaloids are specialized fungal metabolites that are important as the bases of several pharmaceuticals. Many ergot alkaloids are derivatives of lysergic acid (LA) and have vasoconstrictive activity, whereas several dihydrolysergic acid (DHLA) derivatives are vasorelaxant. The pathway to LA is established, with the P450 monooxygenase CloA playing a key role in oxidizing its substrate agroclavine to LA. We analyzed the activities of products of cloA alleles from different fungi relative to DHLA biosynthesis by expressing them in a mutant of the fungus Neosartorya fumigata that accumulates festuclavine, the precursor to DHLA. Transformants expressing CloA from Epichloë typhina × Epichloë festucae, which oxidizes agroclavine to LA, failed to oxidize festuclavine to DHLA. In substrate feeding experiments, these same transformants oxidized exogenously supplied agroclavine to LA, indicating that a functional CloA was produced. A genomic clone of cloA from Claviceps africana, a sorghum ergot fungus that produces a DHLA derivative, was cloned and expressed in the festuclavine-accumulating mutant of N. fumigata, but several introns in this genomic clone were not processed properly. Expression of a synthetic intron-free version of C. africanacloA resulted in the accumulation of DHLA as assessed by fluorescence high-pressure liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). In substrate feeding experiments, the C. africana CloA also accepted agroclavine as the substrate, oxidizing it to LA. The data indicate that a specialized allele of cloA is required for DHLA biosynthesis and that the pharmaceutically important compound DHLA can be produced in engineered N. fumigataIMPORTANCE Ergot alkaloids are fungal metabolites that have impacted humankind historically as poisons and more recently as pharmaceuticals used to treat dementia, migraines, and other disorders. Much is known about the biosynthesis of ergot alkaloids that are derived from lysergic acid (LA), but important questions remain about a parallel pathway to ergot alkaloids derived from dihydrolysergic acid (DHLA). DHLA-derived alkaloids have minor structural differences compared to LA-derived alkaloids but can have very different activities. To understand how DHLA is made, we analyzed activities of a key enzyme in the DHLA pathway and found that it differed from its counterpart in the LA pathway. Our data indicate a critical difference between the two pathways and provide a strategy for producing DHLA by modifying a model fungus. The ability to produce DHLA in a model fungus may facilitate synthesis of DHLA-derived pharmaceuticals.
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Affiliation(s)
- Stephanie L Arnold
- West Virginia University, Division of Plant and Soil Sciences, Genetics and Developmental Biology Program, Morgantown, West Virginia, USA
| | - Daniel G Panaccione
- West Virginia University, Division of Plant and Soil Sciences, Genetics and Developmental Biology Program, Morgantown, West Virginia, USA
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General trends in selectively driven codon usage biases in the domain archaea. J Mol Evol 2014; 79:105-10. [PMID: 25239794 DOI: 10.1007/s00239-014-9647-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
Abstract
Since the advent of rapid techniques for sequencing DNA in the mid 70's, it became clear that all codons coding for the same amino acid are not used according to neutral expectations. In the last 30 years, several theories were proposed for explaining this fact. However, the most important concepts were the result of analyses carried out in Bacteria, and unicellular and multicellular eukaryotes like mammals (in other words, in two of the three Domains of life). In this communication, we study the main forces that shape codon usage in Archaeae under an evolutionary perspective. This is important because, as known, the orthologous genes related with the informational system in this Domain (replication, transcription and translation) are more similar to eukaryotes than to Bacteria. Our results show that the effect of selection acting at the level of translation is present in the Domain but mainly restricted to only a phylum (Euryarchaeota) and therefore is not as extended as in Bacteria. Besides, we describe the phylogenetic distribution of translational optimal codons and estimate the effect of selection acting at the level of accuracy. Finally, we discuss these results under some peculiarities that characterize this Domain.
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12
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Liu W, Mellado L, Espeso EA, Sealy-Lewis HM. In Aspergillus nidulans the suppressors suaA and suaC code for release factors eRF1 and eRF3 and suaD codes for a glutamine tRNA. G3 (BETHESDA, MD.) 2014; 4:1047-57. [PMID: 24727290 PMCID: PMC4065248 DOI: 10.1534/g3.114.010702] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 03/25/2014] [Indexed: 11/24/2022]
Abstract
In Aspergillus nidulans, after extensive mutagenesis, a collection of mutants was obtained and four suppressor loci were identified genetically that could suppress mutations in putative chain termination mutations in different genes. Suppressor mutations in suaB and suaD have a similar restricted spectrum of suppression and suaB111 was previously shown to be an alteration in the anticodon of a gln tRNA. We have shown that like suaB, a suaD suppressor has a mutation in the anticodon of another gln tRNA allowing suppression of UAG mutations. Mutations in suaA and suaC had a broad spectrum of suppression. Four suaA mutations result in alterations in the coding region of the eukaryotic release factor, eRF1, and another suaA mutation has a mutation in the upstream region of eRF1 that prevents splicing of the first intron within the 5'UTR. Epitope tagging of eRF1 in this mutant results in 20% of the level of eRF1 compared to the wild-type. Two mutations in suaC result in alterations in the eukaryotic release factor, eRF3. This is the first description in Aspergillus nidulans of an alteration in eRF3 leading to suppression of chain termination mutations.
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Affiliation(s)
- Wen Liu
- Department of Biological, Biomedical and Environmental Sciences, University of Hull, Hull HU6 7RX, United Kingdom
| | - Laura Mellado
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu, 9, 28040 Madrid, Spain
| | - Eduardo A Espeso
- Department of Cellular and Molecular Biology, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu, 9, 28040 Madrid, Spain
| | - Heather M Sealy-Lewis
- Department of Biological, Biomedical and Environmental Sciences, University of Hull, Hull HU6 7RX, United Kingdom
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13
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Tanaka M, Tokuoka M, Gomi K. Effects of codon optimization on the mRNA levels of heterologous genes in filamentous fungi. Appl Microbiol Biotechnol 2014; 98:3859-67. [PMID: 24682479 DOI: 10.1007/s00253-014-5609-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Revised: 02/07/2014] [Accepted: 02/10/2014] [Indexed: 10/25/2022]
Abstract
Filamentous fungi, particularly Aspergillus species, have recently attracted attention as host organisms for recombinant protein production. Because the secretory yields of heterologous proteins are generally low compared with those of homologous proteins or proteins from closely related fungal species, several strategies to produce substantial amounts of recombinant proteins have been conducted. Codon optimization is a powerful tool for improving the production levels of heterologous proteins. Although codon optimization is generally believed to improve the translation efficiency of heterologous genes without affecting their mRNA levels, several studies have indicated that codon optimization causes an increase in the steady-state mRNA levels of heterologous genes in filamentous fungi. However, the mechanism that determines the low mRNA levels when native heterologous genes are expressed was poorly understood. We recently showed that the transcripts of heterologous genes are polyadenylated prematurely within the coding region and that the heterologous gene transcripts can be stabilized significantly by codon optimization, which is probably attributable to the prevention of premature polyadenylation in Aspergillus oryzae. In this review, we describe the detailed mechanism of premature polyadenylation and the rapid degradation of mRNA transcripts derived from heterologous genes in filamentous fungi.
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Affiliation(s)
- Mizuki Tanaka
- Department of Bioindustrial Informatics and Genomics, Laboratory of Bioindustrial Genomics, Graduate School of Agricultural Science, Tohoku University, 1-1 Tsutsumidori-Amamiyamachi, Aoba-ku, Sendai, 981-8555, Japan,
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