Mistranslation in Candida albicans
Autor(a) principal: | |
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Data de Publicação: | 2011 |
Tipo de documento: | Dissertação |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10773/8156 |
Resumo: | The genetic code establishes the rules that determine the transfer of genetic information from nucleic acids to proteins. The importance of the genetic code in genome decoding and its high conservation suggests that its evolution is highly restricted or even frozen. Despite this, various prokaryotic and eukaryotic genetic code alterations have been found, showing that the code is surprisingly flexible. For instance, the human pathogen Candida albicans contains an ambiguous tRNACAG that decodes a CUG codon as Ser (97%) and as Leu (3%). To further study ambiguity in other amino acid codons, we have engineered 8 mutant tRNASer that misincorporate Ser at 8 different codons belonging to distinct amino acids families (Glu, Arg, Asn, Cys, Phe, Gln, His and Pro) in Candida albicans. The wild-type tRNA was subjected to site-directed mutagenesis in order to change its anticodon to CUC, CCU, GUU, GCA, GAA, CUG, GUG and GGG. The tRNA stability, the cellular changes and the stress response of the resulting mistranslating strains were evaluated through northern blot analysis, cell transformation efficiency, growth rate and expression of a HSP104-GFP reporter system. A phenotypic screening probing various environmental stress conditions was performed in order to further characterize these strains. Experimental data suggest that these genetic code ambiguities affect fitness negatively in standard growth conditions and introduce growth advantages in presence of stress conditions. Thus, stress response triggered by codon ambiguity increase adaptation potential. |
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Mistranslation in Candida albicansBiologia molecularTradução genéticaÁcido ribonucleicoCódigo genéticoThe genetic code establishes the rules that determine the transfer of genetic information from nucleic acids to proteins. The importance of the genetic code in genome decoding and its high conservation suggests that its evolution is highly restricted or even frozen. Despite this, various prokaryotic and eukaryotic genetic code alterations have been found, showing that the code is surprisingly flexible. For instance, the human pathogen Candida albicans contains an ambiguous tRNACAG that decodes a CUG codon as Ser (97%) and as Leu (3%). To further study ambiguity in other amino acid codons, we have engineered 8 mutant tRNASer that misincorporate Ser at 8 different codons belonging to distinct amino acids families (Glu, Arg, Asn, Cys, Phe, Gln, His and Pro) in Candida albicans. The wild-type tRNA was subjected to site-directed mutagenesis in order to change its anticodon to CUC, CCU, GUU, GCA, GAA, CUG, GUG and GGG. The tRNA stability, the cellular changes and the stress response of the resulting mistranslating strains were evaluated through northern blot analysis, cell transformation efficiency, growth rate and expression of a HSP104-GFP reporter system. A phenotypic screening probing various environmental stress conditions was performed in order to further characterize these strains. Experimental data suggest that these genetic code ambiguities affect fitness negatively in standard growth conditions and introduce growth advantages in presence of stress conditions. Thus, stress response triggered by codon ambiguity increase adaptation potential.O código genético estabelece regras que determinam a transferência de informação genética a partir dos ácidos nucleicos para proteínas. A importância do código genético na descodificação do genoma e sua alta conservação sugere que a sua evolução é altamente restrita. Apesar disso, várias alterações no código genético dos procariotas e eucariotas têm sido encontradas, mostrando que o código é surpreendentemente flexível. Por exemplo, o patogénico humano Candida albicans contém um tRNACAG ambíguo que descodifica o codão CUG como Ser (97%) e como Leu (3%). Para continuar o estudo da ambiguidade noutros codões, induzimos 8 tRNASer mutantes, que incorporam incorretamente o aminoácido serina a 8 codões diferentes, pertencentes a distintas famílias de aminoácidos (Glu, Arg, Asn, Cys, Phe, Gln, His e Pro), em Candida albicans. O tRNA não mutado foi submetido a mutagénese dirigida, a fim de modificar o seu anticodão UGA para CUC, CCU, GUU, GCA, GAA, CUG, GUG e GGG. A estabilidade do tRNA, as alterações celulares e resposta ao stress das estirpes mutantes resultantes foram avaliadas através da análise de Northern blot, da eficiência de transformação das células, da taxa de crescimento e da expressão do sistema repórter HSP104-GFP. Além disso, a caracterização fenotípica em determinadas condições de stress foi realizada com o intuito de caracterizar melhor essas estirpes. Os dados experimentais sugerem que essas ambiguidades ao código genético afetam negativamente a aptidão das células em condições de crescimento normais e introduzem vantagens no crescimento na presença de condições de stress. Assim, a resposta ao stress provocada pela ambiguidade dos codões pode aumentar o potencial de adaptação.Universidade de Aveiro2018-07-20T14:00:36Z2011-12-20T00:00:00Z2011-12-202013-12-20T09:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisapplication/pdfhttp://hdl.handle.net/10773/8156engSousa, Diana Sofia Ortiga deinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-02-22T11:13:58Zoai:ria.ua.pt:10773/8156Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-20T02:45:30.169848Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Mistranslation in Candida albicans |
title |
Mistranslation in Candida albicans |
spellingShingle |
Mistranslation in Candida albicans Sousa, Diana Sofia Ortiga de Biologia molecular Tradução genética Ácido ribonucleico Código genético |
title_short |
Mistranslation in Candida albicans |
title_full |
Mistranslation in Candida albicans |
title_fullStr |
Mistranslation in Candida albicans |
title_full_unstemmed |
Mistranslation in Candida albicans |
title_sort |
Mistranslation in Candida albicans |
author |
Sousa, Diana Sofia Ortiga de |
author_facet |
Sousa, Diana Sofia Ortiga de |
author_role |
author |
dc.contributor.author.fl_str_mv |
Sousa, Diana Sofia Ortiga de |
dc.subject.por.fl_str_mv |
Biologia molecular Tradução genética Ácido ribonucleico Código genético |
topic |
Biologia molecular Tradução genética Ácido ribonucleico Código genético |
description |
The genetic code establishes the rules that determine the transfer of genetic information from nucleic acids to proteins. The importance of the genetic code in genome decoding and its high conservation suggests that its evolution is highly restricted or even frozen. Despite this, various prokaryotic and eukaryotic genetic code alterations have been found, showing that the code is surprisingly flexible. For instance, the human pathogen Candida albicans contains an ambiguous tRNACAG that decodes a CUG codon as Ser (97%) and as Leu (3%). To further study ambiguity in other amino acid codons, we have engineered 8 mutant tRNASer that misincorporate Ser at 8 different codons belonging to distinct amino acids families (Glu, Arg, Asn, Cys, Phe, Gln, His and Pro) in Candida albicans. The wild-type tRNA was subjected to site-directed mutagenesis in order to change its anticodon to CUC, CCU, GUU, GCA, GAA, CUG, GUG and GGG. The tRNA stability, the cellular changes and the stress response of the resulting mistranslating strains were evaluated through northern blot analysis, cell transformation efficiency, growth rate and expression of a HSP104-GFP reporter system. A phenotypic screening probing various environmental stress conditions was performed in order to further characterize these strains. Experimental data suggest that these genetic code ambiguities affect fitness negatively in standard growth conditions and introduce growth advantages in presence of stress conditions. Thus, stress response triggered by codon ambiguity increase adaptation potential. |
publishDate |
2011 |
dc.date.none.fl_str_mv |
2011-12-20T00:00:00Z 2011-12-20 2013-12-20T09:00:00Z 2018-07-20T14:00:36Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10773/8156 |
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http://hdl.handle.net/10773/8156 |
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eng |
language |
eng |
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info:eu-repo/semantics/openAccess |
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openAccess |
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application/pdf |
dc.publisher.none.fl_str_mv |
Universidade de Aveiro |
publisher.none.fl_str_mv |
Universidade de Aveiro |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
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Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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RCAAP |
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RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
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Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
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