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Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA

N-nitroso compounds represent a common type of environmental and endogenous DNA-damaging agents. After metabolic activation, many N-nitroso compounds are converted into a diazoacetate intermediate that can react with nucleobases to give carboxymethylated DNA adducts such as N3-carboxymethylthymidine...

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Autores principales: You, Changjun, Wang, Jianshuang, Dai, Xiaoxia, Wang, Yinsheng
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333421/
https://www.ncbi.nlm.nih.gov/pubmed/25572317
http://dx.doi.org/10.1093/nar/gku1391
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author You, Changjun
Wang, Jianshuang
Dai, Xiaoxia
Wang, Yinsheng
author_facet You, Changjun
Wang, Jianshuang
Dai, Xiaoxia
Wang, Yinsheng
author_sort You, Changjun
collection PubMed
description N-nitroso compounds represent a common type of environmental and endogenous DNA-damaging agents. After metabolic activation, many N-nitroso compounds are converted into a diazoacetate intermediate that can react with nucleobases to give carboxymethylated DNA adducts such as N3-carboxymethylthymidine (N3-CMdT) and O(4)-carboxymethylthymidine (O(4)-CMdT). In this study, we constructed non-replicative plasmids carrying a single N3-CMdT or O(4)-CMdT, site-specifically positioned in the transcribed strand, to investigate how these lesions compromise the flow of genetic information during transcription. Our results revealed that both N3-CMdT and O(4)-CMdT substantially inhibited DNA transcription mediated by T7 RNA polymerase or human RNA polymerase II in vitro and in human cells. In addition, we found that N3-CMdT and O(4)-CMdT were miscoding lesions and predominantly directed the misinsertion of uridine and guanosine, respectively. Our results also suggested that these carboxymethylated thymidine lesions may constitute efficient substrates for transcription-coupled nucleotide excision repair in human cells. These findings provided important new insights into the biological consequences of the carboxymethylated DNA lesions in living cells.
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spelling pubmed-43334212015-02-26 Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA You, Changjun Wang, Jianshuang Dai, Xiaoxia Wang, Yinsheng Nucleic Acids Res Genome Integrity, Repair and Replication N-nitroso compounds represent a common type of environmental and endogenous DNA-damaging agents. After metabolic activation, many N-nitroso compounds are converted into a diazoacetate intermediate that can react with nucleobases to give carboxymethylated DNA adducts such as N3-carboxymethylthymidine (N3-CMdT) and O(4)-carboxymethylthymidine (O(4)-CMdT). In this study, we constructed non-replicative plasmids carrying a single N3-CMdT or O(4)-CMdT, site-specifically positioned in the transcribed strand, to investigate how these lesions compromise the flow of genetic information during transcription. Our results revealed that both N3-CMdT and O(4)-CMdT substantially inhibited DNA transcription mediated by T7 RNA polymerase or human RNA polymerase II in vitro and in human cells. In addition, we found that N3-CMdT and O(4)-CMdT were miscoding lesions and predominantly directed the misinsertion of uridine and guanosine, respectively. Our results also suggested that these carboxymethylated thymidine lesions may constitute efficient substrates for transcription-coupled nucleotide excision repair in human cells. These findings provided important new insights into the biological consequences of the carboxymethylated DNA lesions in living cells. Oxford University Press 2015-01-30 2015-01-08 /pmc/articles/PMC4333421/ /pubmed/25572317 http://dx.doi.org/10.1093/nar/gku1391 Text en © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research. http://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
spellingShingle Genome Integrity, Repair and Replication
You, Changjun
Wang, Jianshuang
Dai, Xiaoxia
Wang, Yinsheng
Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title_full Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title_fullStr Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title_full_unstemmed Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title_short Transcriptional inhibition and mutagenesis induced by N-nitroso compound-derived carboxymethylated thymidine adducts in DNA
title_sort transcriptional inhibition and mutagenesis induced by n-nitroso compound-derived carboxymethylated thymidine adducts in dna
topic Genome Integrity, Repair and Replication
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4333421/
https://www.ncbi.nlm.nih.gov/pubmed/25572317
http://dx.doi.org/10.1093/nar/gku1391
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