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Quantification of 8-oxoG in Plant Telomeres

Chemical modifications in DNA impact gene regulation and chromatin structure. DNA oxidation, for example, alters gene expression, DNA synthesis and cell cycle progression. Modification of telomeric DNA by oxidation is emerging as a marker of genotoxic damage and is associated with reduced genome int...

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Autores principales: Castillo-González, Claudia, Barbero Barcenilla, Borja, Young, Pierce G., Hall, Emily, Shippen, Dorothy E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102096/
https://www.ncbi.nlm.nih.gov/pubmed/35563379
http://dx.doi.org/10.3390/ijms23094990
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author Castillo-González, Claudia
Barbero Barcenilla, Borja
Young, Pierce G.
Hall, Emily
Shippen, Dorothy E.
author_facet Castillo-González, Claudia
Barbero Barcenilla, Borja
Young, Pierce G.
Hall, Emily
Shippen, Dorothy E.
author_sort Castillo-González, Claudia
collection PubMed
description Chemical modifications in DNA impact gene regulation and chromatin structure. DNA oxidation, for example, alters gene expression, DNA synthesis and cell cycle progression. Modification of telomeric DNA by oxidation is emerging as a marker of genotoxic damage and is associated with reduced genome integrity and changes in telomere length and telomerase activity. 8-oxoguanine (8-oxoG) is the most studied and common outcome of oxidative damage in DNA. The G-rich nature of telomeric DNA is proposed to make it a hotspot for oxidation, but because telomeres make up only a tiny fraction of the genome, it has been difficult to directly test this hypothesis by studying dynamic DNA modifications specific to this region in vivo. Here, we present a new, robust method to differentially enrich telomeric DNA in solution, coupled with downstream methods for determination of chemical modification. Specifically, we measure 8-oxoG in Arabidopsis thaliana telomeres under normal and oxidative stress conditions. We show that telomere length is unchanged in response to oxidative stress in three different wild-type accessions. Furthermore, we report that while telomeric DNA comprises only 0.02–0.07% of the total genome, telomeres contribute between 0.2 and 15% of the total 8-oxoG. That is, plant telomeres accumulate 8-oxoG at levels approximately 100-fold higher than the rest of the genome under standard growth conditions. Moreover, they are the primary targets of further damage upon oxidative stress. Interestingly, the accumulation of 8-oxoG in the chromosome body seems to be inversely proportional to telomere length. These findings support the hypothesis that telomeres are hotspots of 8-oxoG and may function as sentinels of oxidative stress in plants.
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spelling pubmed-91020962022-05-14 Quantification of 8-oxoG in Plant Telomeres Castillo-González, Claudia Barbero Barcenilla, Borja Young, Pierce G. Hall, Emily Shippen, Dorothy E. Int J Mol Sci Article Chemical modifications in DNA impact gene regulation and chromatin structure. DNA oxidation, for example, alters gene expression, DNA synthesis and cell cycle progression. Modification of telomeric DNA by oxidation is emerging as a marker of genotoxic damage and is associated with reduced genome integrity and changes in telomere length and telomerase activity. 8-oxoguanine (8-oxoG) is the most studied and common outcome of oxidative damage in DNA. The G-rich nature of telomeric DNA is proposed to make it a hotspot for oxidation, but because telomeres make up only a tiny fraction of the genome, it has been difficult to directly test this hypothesis by studying dynamic DNA modifications specific to this region in vivo. Here, we present a new, robust method to differentially enrich telomeric DNA in solution, coupled with downstream methods for determination of chemical modification. Specifically, we measure 8-oxoG in Arabidopsis thaliana telomeres under normal and oxidative stress conditions. We show that telomere length is unchanged in response to oxidative stress in three different wild-type accessions. Furthermore, we report that while telomeric DNA comprises only 0.02–0.07% of the total genome, telomeres contribute between 0.2 and 15% of the total 8-oxoG. That is, plant telomeres accumulate 8-oxoG at levels approximately 100-fold higher than the rest of the genome under standard growth conditions. Moreover, they are the primary targets of further damage upon oxidative stress. Interestingly, the accumulation of 8-oxoG in the chromosome body seems to be inversely proportional to telomere length. These findings support the hypothesis that telomeres are hotspots of 8-oxoG and may function as sentinels of oxidative stress in plants. MDPI 2022-04-30 /pmc/articles/PMC9102096/ /pubmed/35563379 http://dx.doi.org/10.3390/ijms23094990 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/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 (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Castillo-González, Claudia
Barbero Barcenilla, Borja
Young, Pierce G.
Hall, Emily
Shippen, Dorothy E.
Quantification of 8-oxoG in Plant Telomeres
title Quantification of 8-oxoG in Plant Telomeres
title_full Quantification of 8-oxoG in Plant Telomeres
title_fullStr Quantification of 8-oxoG in Plant Telomeres
title_full_unstemmed Quantification of 8-oxoG in Plant Telomeres
title_short Quantification of 8-oxoG in Plant Telomeres
title_sort quantification of 8-oxog in plant telomeres
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102096/
https://www.ncbi.nlm.nih.gov/pubmed/35563379
http://dx.doi.org/10.3390/ijms23094990
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