Details

Autor(en) / Beteiligte

• Silva, Larissa G.
• Lorenzetti, Alan P.R.
• Ribeiro, Rodolfo A.
• Alves, Ingrid R.
• Leaden, Laura
• Galhardo, Rodrigo S.
• Koide, Tie
• Marques, Marilis V.

Titel

OxyR and the hydrogen peroxide stress response in Caulobacter crescentus

Ist Teil von

• Gene, 2019-06, Vol.700, p.70-84

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2019

Quelle

MEDLINE

Beschreibungen/Notizen

• 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 free-living bacterium Caulobacter crescentus, a whole transcriptome analysis of wild type and ΔoxyR 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 silico 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. •The C. crescentus response to H2O2 was characterized by transcriptomics analysis.•OxyR is required for the expression of 103 genes in response to H2O2.•Genes for assimilative sulfate reduction were downregulated in H2O2 exposure.•Histidine biosynthesis genes were upregulated in H2O2 exposure.•A non-coding RNA was upregulated upon H2O2 exposure independently of OxyR