HpoR, a novel c-di-GMP effective transcription factor, links the second messenger's regulatory function to the mycobacterial antioxidant defense.
Nucleic Acids Res
; 46(7): 3595-3611, 2018 04 20.
Article
in En
| MEDLINE
| ID: mdl-29490073
ABSTRACT
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 11. 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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Second Messenger Systems
/
Biofilms
/
Mycobacterium smegmatis
/
Antioxidants
Language:
En
Journal:
Nucleic Acids Res
Year:
2018
Document type:
Article
Affiliation country:
China