title: MerR and ChrR mediate blue light induced photo-oxidative stress response at the transcriptional level in Vibrio cholerae.
abstract: Blue light (BL) is a major environmental factor that affects the physiology, behavior, and infectivity of bacteria as it contributes to the generation of reactive oxygen species (ROS) while increasing photo-oxidative stress in cells. However, precise photo-oxidative response mechanism in non-phototrophic bacteria is yet to be elucidated. In this study, we investigated the effect of BL in Vibrio cholerae by using genetics and transcriptome profiling. Genome-wide analysis revealed that transcription of 6.3% of V. cholerae genes were regulated by BL. We further showed that BL enhances ROS production, which is generated through the oxidative phosphorylation. To understand signaling mechanisms, we generated several knockouts and analyzed their transcriptome under BL exposure. Studies with a double-knockout confirm an anti-sigma factor (ChrR) and putative metalloregulatory-like protein (MerR) are responsible for the genome-wide regulation to BL response in V. cholerae. Collectively, these results demonstrate that MerR-like proteins, in addition to ChrR, are required for V. cholerae to mount an appropriate response against photo-oxidative stress induced by BL. Outside its natural host, V. cholerae can survive for extended periods in natural aquatic environments. Therefore, the regulation of light response for V. cholerae may be a critical cellular process for its survival in these environments.
authors.affiliation: Computational Science and Engineering, Koc University, Rumeli Feneri Yolu, Sariyer, Istanbul, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Tardu
authors.affiliation: Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, Sariyer, Istanbul, Turkey.
authors.forename: Selma
authors.initials: S
authors.lastname: Bulut
authors.affiliation: Computational Science and Engineering, Koc University, Rumeli Feneri Yolu, Sariyer, Istanbul, Turkey.|Chemical and Biological Engineering, Koc University, Rumeli Feneri Yolu, Sariyer, Istanbul, Turkey.|Molecular Biology and Genetics, Koc University, Rumeli Feneri Yolu, Sariyer, Istanbul, Turkey.
authors.forename: Ibrahim Halil
authors.initials: IH
authors.lastname: Kavakli
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D056931:Cryptochromes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020869:Gene Expression Profiling; D016680:Genome, Bacterial; D008027:Light; D018384:Oxidative Stress / Q000528:radiation effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012808:Sigma Factor / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000528:radiation effects; D014734:Vibrio cholerae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D056931:Cryptochromes; D004268:DNA-Binding Proteins; C051124:MerR protein, Bacteria; D017382:Reactive Oxygen Species; D012808:Sigma Factor