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An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression

Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are...

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Autores principales: Chung, Kin Pan, Loiacono, F Vanessa, Neupert, Juliane, Wu, Mengting, Bock, Ralph
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10639063/
https://www.ncbi.nlm.nih.gov/pubmed/37855670
http://dx.doi.org/10.1093/nar/gkad816
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author Chung, Kin Pan
Loiacono, F Vanessa
Neupert, Juliane
Wu, Mengting
Bock, Ralph
author_facet Chung, Kin Pan
Loiacono, F Vanessa
Neupert, Juliane
Wu, Mengting
Bock, Ralph
author_sort Chung, Kin Pan
collection PubMed
description Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5′ untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine–Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine–Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields.
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spelling pubmed-106390632023-11-15 An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression Chung, Kin Pan Loiacono, F Vanessa Neupert, Juliane Wu, Mengting Bock, Ralph Nucleic Acids Res Synthetic Biology and Bioengineering Riboregulators such as riboswitches and RNA thermometers provide simple, protein-independent tools to control gene expression at the post-transcriptional level. In bacteria, RNA thermometers regulate protein synthesis in response to temperature shifts. Thermometers outside of the bacterial world are rare, and in organellar genomes, no RNA thermometers have been identified to date. Here we report the discovery of an RNA thermometer in a chloroplast gene of the unicellular green alga Chlamydomonas reinhardtii. The thermometer, residing in the 5′ untranslated region of the psaA messenger RNA forms a hairpin-type secondary structure that masks the Shine–Dalgarno sequence at 25°C. At 40°C, melting of the secondary structure increases accessibility of the Shine–Dalgarno sequence to initiating ribosomes, thus enhancing protein synthesis. By targeted nucleotide substitutions and transfer of the thermometer into Escherichia coli, we show that the secondary structure is necessary and sufficient to confer the thermometer properties. We also demonstrate that the thermometer provides a valuable tool for inducible transgene expression from the Chlamydomonas plastid genome, in that a simple temperature shift of the algal culture can greatly increase recombinant protein yields. Oxford University Press 2023-10-19 /pmc/articles/PMC10639063/ /pubmed/37855670 http://dx.doi.org/10.1093/nar/gkad816 Text en © The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research. https://creativecommons.org/licenses/by/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Synthetic Biology and Bioengineering
Chung, Kin Pan
Loiacono, F Vanessa
Neupert, Juliane
Wu, Mengting
Bock, Ralph
An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title_full An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title_fullStr An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title_full_unstemmed An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title_short An RNA thermometer in the chloroplast genome of Chlamydomonas facilitates temperature-controlled gene expression
title_sort rna thermometer in the chloroplast genome of chlamydomonas facilitates temperature-controlled gene expression
topic Synthetic Biology and Bioengineering
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10639063/
https://www.ncbi.nlm.nih.gov/pubmed/37855670
http://dx.doi.org/10.1093/nar/gkad816
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