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Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo
Reverse gyrase introduces positive supercoils to circular DNA and is implicated in genome stability maintenance in thermophiles. The extremely thermophilic crenarchaeon Sulfolobus encodes two reverse gyrase proteins, TopR1 (topoisomerase reverse gyrase 1) and TopR2, whose functions in thermophilic l...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5535833/ https://www.ncbi.nlm.nih.gov/pubmed/28640207 http://dx.doi.org/10.3390/ijms18071340 |
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author | Han, Wenyuan Feng, Xu She, Qunxin |
author_facet | Han, Wenyuan Feng, Xu She, Qunxin |
author_sort | Han, Wenyuan |
collection | PubMed |
description | Reverse gyrase introduces positive supercoils to circular DNA and is implicated in genome stability maintenance in thermophiles. The extremely thermophilic crenarchaeon Sulfolobus encodes two reverse gyrase proteins, TopR1 (topoisomerase reverse gyrase 1) and TopR2, whose functions in thermophilic life remain to be demonstrated. Here, we investigated the roles of TopR1 in genome stability maintenance in S. islandicus in response to the treatment of methyl methanesulfonate (MMS), a DNA alkylation agent. Lethal MMS treatment induced two successive events: massive chromosomal DNA backbone breakage and subsequent DNA degradation. The former occurred immediately after drug treatment, leading to chromosomal DNA degradation that concurred with TopR1 degradation, followed by chromatin protein degradation and DNA-less cell formation. To gain a further insight into TopR1 function, the expression of the enzyme was reduced in S. islandicus cells using a CRISPR-mediated mRNA interference approach (CRISPRi) in which topR1 mRNAs were targeted for degradation by endogenous III-B CRISPR-Cas systems. We found that the TopR1 level was reduced in the S. islandicus CRISPRi cells and that the cells underwent accelerated genomic DNA degradation during MMS treatment, accompanied by a higher rate of cell death. Taken together, these results indicate that TopR1 probably facilitates genome integrity maintenance by protecting DNA breaks from thermo-degradation in vivo. |
format | Online Article Text |
id | pubmed-5535833 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-55358332017-08-04 Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo Han, Wenyuan Feng, Xu She, Qunxin Int J Mol Sci Article Reverse gyrase introduces positive supercoils to circular DNA and is implicated in genome stability maintenance in thermophiles. The extremely thermophilic crenarchaeon Sulfolobus encodes two reverse gyrase proteins, TopR1 (topoisomerase reverse gyrase 1) and TopR2, whose functions in thermophilic life remain to be demonstrated. Here, we investigated the roles of TopR1 in genome stability maintenance in S. islandicus in response to the treatment of methyl methanesulfonate (MMS), a DNA alkylation agent. Lethal MMS treatment induced two successive events: massive chromosomal DNA backbone breakage and subsequent DNA degradation. The former occurred immediately after drug treatment, leading to chromosomal DNA degradation that concurred with TopR1 degradation, followed by chromatin protein degradation and DNA-less cell formation. To gain a further insight into TopR1 function, the expression of the enzyme was reduced in S. islandicus cells using a CRISPR-mediated mRNA interference approach (CRISPRi) in which topR1 mRNAs were targeted for degradation by endogenous III-B CRISPR-Cas systems. We found that the TopR1 level was reduced in the S. islandicus CRISPRi cells and that the cells underwent accelerated genomic DNA degradation during MMS treatment, accompanied by a higher rate of cell death. Taken together, these results indicate that TopR1 probably facilitates genome integrity maintenance by protecting DNA breaks from thermo-degradation in vivo. MDPI 2017-06-22 /pmc/articles/PMC5535833/ /pubmed/28640207 http://dx.doi.org/10.3390/ijms18071340 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Han, Wenyuan Feng, Xu She, Qunxin Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title | Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title_full | Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title_fullStr | Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title_full_unstemmed | Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title_short | Reverse Gyrase Functions in Genome Integrity Maintenance by Protecting DNA Breaks In Vivo |
title_sort | reverse gyrase functions in genome integrity maintenance by protecting dna breaks in vivo |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5535833/ https://www.ncbi.nlm.nih.gov/pubmed/28640207 http://dx.doi.org/10.3390/ijms18071340 |
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