RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin

ABSTRACT We have previously identified Vibrio cholerae mutants in which the stress response to subinhibitory concentrations of aminoglycoside is altered. One gene identified, VC1636, encodes a putative DNA/RNA helicase, recently named RadD in Escherichia coli. Here we combined extensive genetic char...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Veronica Negro, Evelyne Krin, Sebastian Aguilar Pierlé, Thibault Chaze, Quentin Giai Gianetto, Sean P. Kennedy, Mariette Matondo, Didier Mazel, Zeynep Baharoglu
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2019
Materias:	DNA repair R-loop antibiotic resistance Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/4591dab9652642f983a56df0a714676c
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:4591dab9652642f983a56df0a714676c
record_format	dspace
spelling	oai:doaj.org-article:4591dab9652642f983a56df0a714676c2021-11-15T16:22:11ZRadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin10.1128/mBio.01173-192150-7511https://doaj.org/article/4591dab9652642f983a56df0a714676c2019-08-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.01173-19https://doaj.org/toc/2150-7511ABSTRACT We have previously identified Vibrio cholerae mutants in which the stress response to subinhibitory concentrations of aminoglycoside is altered. One gene identified, VC1636, encodes a putative DNA/RNA helicase, recently named RadD in Escherichia coli. Here we combined extensive genetic characterization and high-throughput approaches in order to identify partners and molecular mechanisms involving RadD. We show that double-strand DNA breaks (DSBs) are formed upon subinhibitory tobramycin treatment in the absence of radD and recBCD and that formation of these DSBs can be overcome by RNase H1 overexpression. Loss of RNase H1, or of the transcription-translation coupling factor EF-P, is lethal in the radD deletion mutant. We propose that R-loops are formed upon sublethal aminoglycoside treatment, leading to the formation of DSBs that can be repaired by the RecBCD homologous recombination pathway, and that RadD counteracts such R-loop accumulation. We discuss how R-loops that can occur upon translation-transcription uncoupling could be the link between tobramycin treatment and DNA break formation. IMPORTANCE Bacteria frequently encounter low concentrations of antibiotics. Active antibiotics are commonly detected in soil and water at concentrations much below lethal concentration. Although sub-MICs of antibiotics do not kill bacteria, they can have a major impact on bacterial populations by contributing to the development of antibiotic resistance through mutations in originally sensitive bacteria or acquisition of DNA from resistant bacteria. It was shown that concentrations as low as 100-fold below the MIC can actually lead to the selection of antibiotic-resistant cells. We seek to understand how bacterial cells react to such antibiotic concentrations using E. coli, the Gram-negative bacterial paradigm, and V. cholerae, the causative agent of cholera. Our findings shed light on the processes triggered at the DNA level by antibiotics targeting translation, how damage occurs, and what the bacterial strategies are to respond to such DNA damage.Veronica NegroEvelyne KrinSebastian Aguilar PierléThibault ChazeQuentin Giai GianettoSean P. KennedyMariette MatondoDidier MazelZeynep BaharogluAmerican Society for MicrobiologyarticleDNA repairR-loopantibiotic resistanceMicrobiologyQR1-502ENmBio, Vol 10, Iss 4 (2019)
institution	DOAJ
collection	DOAJ
language	EN
topic	DNA repair R-loop antibiotic resistance Microbiology QR1-502
spellingShingle	DNA repair R-loop antibiotic resistance Microbiology QR1-502 Veronica Negro Evelyne Krin Sebastian Aguilar Pierlé Thibault Chaze Quentin Giai Gianetto Sean P. Kennedy Mariette Matondo Didier Mazel Zeynep Baharoglu RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
description	ABSTRACT We have previously identified Vibrio cholerae mutants in which the stress response to subinhibitory concentrations of aminoglycoside is altered. One gene identified, VC1636, encodes a putative DNA/RNA helicase, recently named RadD in Escherichia coli. Here we combined extensive genetic characterization and high-throughput approaches in order to identify partners and molecular mechanisms involving RadD. We show that double-strand DNA breaks (DSBs) are formed upon subinhibitory tobramycin treatment in the absence of radD and recBCD and that formation of these DSBs can be overcome by RNase H1 overexpression. Loss of RNase H1, or of the transcription-translation coupling factor EF-P, is lethal in the radD deletion mutant. We propose that R-loops are formed upon sublethal aminoglycoside treatment, leading to the formation of DSBs that can be repaired by the RecBCD homologous recombination pathway, and that RadD counteracts such R-loop accumulation. We discuss how R-loops that can occur upon translation-transcription uncoupling could be the link between tobramycin treatment and DNA break formation. IMPORTANCE Bacteria frequently encounter low concentrations of antibiotics. Active antibiotics are commonly detected in soil and water at concentrations much below lethal concentration. Although sub-MICs of antibiotics do not kill bacteria, they can have a major impact on bacterial populations by contributing to the development of antibiotic resistance through mutations in originally sensitive bacteria or acquisition of DNA from resistant bacteria. It was shown that concentrations as low as 100-fold below the MIC can actually lead to the selection of antibiotic-resistant cells. We seek to understand how bacterial cells react to such antibiotic concentrations using E. coli, the Gram-negative bacterial paradigm, and V. cholerae, the causative agent of cholera. Our findings shed light on the processes triggered at the DNA level by antibiotics targeting translation, how damage occurs, and what the bacterial strategies are to respond to such DNA damage.
format	article
author	Veronica Negro Evelyne Krin Sebastian Aguilar Pierlé Thibault Chaze Quentin Giai Gianetto Sean P. Kennedy Mariette Matondo Didier Mazel Zeynep Baharoglu
author_facet	Veronica Negro Evelyne Krin Sebastian Aguilar Pierlé Thibault Chaze Quentin Giai Gianetto Sean P. Kennedy Mariette Matondo Didier Mazel Zeynep Baharoglu
author_sort	Veronica Negro
title	RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
title_short	RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
title_full	RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
title_fullStr	RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
title_full_unstemmed	RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin
title_sort	radd contributes to r-loop avoidance in sub-mic tobramycin
publisher	American Society for Microbiology
publishDate	2019
url	https://doaj.org/article/4591dab9652642f983a56df0a714676c
work_keys_str_mv	AT veronicanegro raddcontributestorloopavoidanceinsubmictobramycin AT evelynekrin raddcontributestorloopavoidanceinsubmictobramycin AT sebastianaguilarpierle raddcontributestorloopavoidanceinsubmictobramycin AT thibaultchaze raddcontributestorloopavoidanceinsubmictobramycin AT quentingiaigianetto raddcontributestorloopavoidanceinsubmictobramycin AT seanpkennedy raddcontributestorloopavoidanceinsubmictobramycin AT mariettematondo raddcontributestorloopavoidanceinsubmictobramycin AT didiermazel raddcontributestorloopavoidanceinsubmictobramycin AT zeynepbaharoglu raddcontributestorloopavoidanceinsubmictobramycin
_version_	1718426900779499520

RadD Contributes to R-Loop Avoidance in Sub-MIC Tobramycin

Ejemplares similares