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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

OxyR and the hydrogen peroxide stress response in Caulobacter crescentus

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Silva, Larissa G. [1] ; Lorenzetti, Alan P. R. [2] ; Ribeiro, Rodolfo A. [1] ; Alves, Ingrid R. [1] ; Leaden, Laura [1] ; Galhardo, Rodrigo S. [1] ; Koide, Tie [2] ; Marques, Marilis V. [1]
Total Authors: 8
[1] Univ Sao Paulo, Dept Microbiol, Inst Ciencias Biomed, Sao Paulo - Brazil
[2] Univ Sao Paulo, Dept Bioquim & Imunol, Fac Med Ribeirao Preto, Ribeirao Preto - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Gene; v. 700, p. 70-84, JUN 5 2019.
Web of Science Citations: 0

Oxidative stress generated by hydrogen peroxide is faced by bacteria when encountering hostile environments. In order to define the physiological and regulatory networks controlling the oxidative stress response in the freeliving bacterium Caulobacter crescentus, a whole transcriptome analysis of wild type and AoxyR strains in the presence of hydrogen peroxide for two different exposure times was carried out. The C. crescentus response to H2O2 includes a decrease of the assimilative sulfate reduction and a shift in the amino acid synthesis pathways into favoring the synthesis of histidine. Moreover, the expression of genes encoding enzymes for the depolymerization of polyhydroxybutyrate was increased, and the RpoH-dependent genes were severely repressed. Based on the expression pattern and sequence analysis, we postulate that OxyR is probably directly required for the induction of three genes (katG, ahpCF). The putative binding of OxyR to the ahpC regulatory region could be responsible for the use of one of two alternative promoters in response to oxidative stress. Nevertheless, OxyR is required for the expression of 103 genes in response to H2O2. Fur and part of its regulon were differentially expressed in response to hydrogen peroxide independently of OxyR. The non-coding RNA OsrA was upregulated in both strains, and an in silica analysis indicated that it may have a regulatory role. This work characterizes the physiological response to H2O2 in C. crescentus, the regulatory networks and differentially regulated genes in oxidative stress and the participation of OxyR in this process. It is proposed that besides OxyR, a second layer of regulation may be achieved by a small regulatory RNA and other transcriptional regulators. (AU)

FAPESP's process: 15/07386-7 - Regulatory RNAs identification in response to iron availability and their mechanisms of action in Caulobacter crescentus
Grantee:Laura Leaden
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 16/06378-3 - Characterization of the DEAD-box RNA helicase CC1478 in Caulobacter crescentus and its regulation
Grantee:Rodolfo Alvarenga Ribeiro
Support type: Scholarships in Brazil - Master
FAPESP's process: 15/21038-1 - The antisense transcriptome of the halophilic archaeon Halobacterium salinarum
Grantee:Tie Koide
Support type: Regular Research Grants
FAPESP's process: 14/04046-8 - Regulatory networks of bacterial stress response
Grantee:Marilis Do Valle Marques
Support type: Research Projects - Thematic Grants
FAPESP's process: 17/03052-2 - Non-coding RNAs derived from insertion sequences in the halophilic archaeon Halobacterium salinarum NRC-1
Grantee:Alan Péricles Rodrigues Lorenzetti
Support type: Scholarships in Brazil - Doctorate