HpoR, a novel c-di-GMP effective transcription factor, links the second messenger's regulatory function to the mycobacterial antioxidant defense
| Autor: | Lihua Hu, Zheng-Guo He, Meng Li, Weihui Li, Jingpeng Zhu, Jiarui Chen, Zhiwei Xie |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Cell signaling Operon 030106 microbiology Mycobacterium smegmatis Regulator Second Messenger Systems Antioxidants 03 medical and health sciences Gene cluster Genetics Promoter Regions Genetic Transcription factor Cyclic GMP Molecular Biology Regulation of gene expression biology Gene Expression Regulation Bacterial Hydrogen Peroxide biology.organism_classification Cell biology DNA-Binding Proteins 030104 developmental biology Biofilms Second messenger system Signal Transduction |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 |
| Popis: | Cyclic di-GMP (c-di-GMP) is a global signaling molecule that widely modulates diverse cellular processes. However, whether or not the c-di-GMP signal participates in regulation of bacterial antioxidant defense is unclear, and the involved regulators remain to be explored. In this study, we characterized HpoR as a novel c-di-GMP effective transcription factor and found a link between the c-di-GMP signal and the antioxidant regulation in Mycobacterium smegmatis. H2O2 stress induces c-di-GMP accumulation in M. smegmatis. High level of c-di-GMP triggers expression of a redox gene cluster, designated as hpoR operon, which is required for the mycobacterial H2O2 resistance. HpoR acts as an inhibitor of the hpoR operon and recognizes a 12-bp motif sequence within the upstream regulatory region of the operon. c-di-GMP specifically binds with HpoR at a ratio of 1:1. Low concentrations of c-di-GMP stimulate the DNA-binding activity of HpoR, whereas high concentrations of the signal molecule inhibit the activity. Strikingly, high level of c-di-GMP de-represses the intracellular association of HpoR with the regulatory region of the hpoR operon in M. smegmatis and enhances the mycobacterial H2O2 resistance. Therefore, we report a novel c-di-GMP effective regulator in mycobacteria, which extends the second messenger’s function to bacterial antioxidant defense. |
| Databáze: | OpenAIRE |
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