The small RNA RyhB homologs from Salmonella typhimurium participate in the response to S-nitrosoglutathione-induced stress

• Published in: Biochemical and biophysical research communications 2014-07, Vol.450 (1), p.641-645
• Main Authors: Calderón, Paulina F., Morales, Eduardo H., Acuña, Lillian G., Fuentes, Danitza N., Gil, Fernando, Porwollik, S., McClelland, Michael, Saavedra, Claudia P., Calderón, Iván L.
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents - pharmacology; GSNO; Nitrosative stress; Oxidative Stress - drug effects; Oxidative Stress - physiology; Reactive Oxygen Species - metabolism; RNA, Bacterial - metabolism; RNA, Messenger - metabolism; RNS; RyhB; S-Nitrosoglutathione - pharmacology; Salmonella typhimurium; Salmonella typhimurium - drug effects; Salmonella typhimurium - physiology; sRNA
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2014.06.031

•The small RNAs RyhB-1 and RyhB-2 are induced in response to GSNO.•In response to GSNO RyhBs down-regulate the expression of cytochrome oxidases.•In response to GSNO RyhBs up-regulate the expression of nitrite reductase system. Typically, the expression of sRNAs is activated in response to environmental stimuli in order to regulate gene expression through post-transcriptional mechanisms. In the present work we show that the Salmonellatyphimurium paralogous sRNAs RyhB-1 and RyhB-2 are induced in response to the nitrosating agent S-nitrosoglutathione (GSNO). Inactivation of these sRNAs decreased S. typhimurium resistance to GSNO and increased the levels of nitrosylated proteins. These results prompted us to evaluate a possible role of these sRNAs in nitrosative stress resistance. RNA profiling was used as a screen to identify novel RyhB-1 and RyhB-2 regulated targets. A subset of genes was filtered based on their potential role in the response to nitrosative stress and their expression was analyzed by quantitative RT-PCR in wild type, single and double mutant strains (ΔryhB1, ΔryhB2 and ΔryhB1 ΔryhB2) treated with GSNO. In response to GSNO RyhB-1 and RyhB-2 negatively regulate the expression of the genes cyoABC (cytochrome bo oxidase), cydB (cytochrome bd oxidase), cybC (cytochrome b-562), and positively regulate the nirBCD operon (nitrite reductase system). Together, these results suggest that RyhB-1 and RyhB-2 finely tune the expression of genes coding for cytochrome oxidases and the nitrate reductase system, allowing the cell to cope with GSNO-induced stress.