Cyclic AMP Receptor Protein Acts as a Transcription Regulator in Response to Stresses in Deinococcus radiodurans

Abstract

The cyclic AMP receptor protein family of transcription factors regulates various metabolic pathways in bacteria, and also play roles in response to environmental changes. Here, we identify four homologs of the CRP family in Deinococcus radiodurans, one of which tolerates extremely high levels of oxidative stress and DNA-damaging reagents. Transcriptional levels of CRP were increased under hydrogen peroxide (H2O2) treatment during the stationary growth phase, indicating that CRPs function in response to oxidative stress. By constructing all CRP single knockout mutants, we found that the dr0997 mutant showed the lowest tolerance toward H2O2, ultraviolet radiation, ionizing radiation, and mitomycin C, while the phenotypes of the dr2362, dr0834, and dr1646 mutants showed slight or no significant differences from those of the wild-type strain. Taking advantage of the conservation of the CRP-binding site in many bacteria, we found that transcription of 18 genes, including genes encoding chromosome-partitioning protein (dr0998), Lon proteases (dr0349 and dr1974), NADH-quinone oxidoreductase (dr1506), thiosulfate sulfurtransferase (dr2531), the DNA repair protein UvsE (dr1819), PprA (dra0346), and RecN (dr1447), are directly regulated by DR0997. Quantitative real-time polymerase chain reaction (qRT-PCR) analyses showed that certain genes involved in anti-oxidative responses, DNA repair, and various cellular pathways are transcriptionally attenuated in the dr0997 mutant. Interestingly, DR0997 also regulate the transcriptional levels of all CRP genes in this bacterium. These data suggest that DR0997 contributes to the extreme stress resistance of D. radiodurans via its regulatory role in multiple cellular pathways, such as anti-oxidation and DNA repair pathways.

Comparative transcriptomic analysis of Listeria monocytogenes reveals upregulation of stress genes and downregulation of virulence genes in response to essential oil extracted from Baccharis psiadioides

“…In addition, the Crp family of transcription factors is involved in various metabolic pathways in bacteria, acting in response to environmental changes. It has been shown that Crp acts as a transcription regulator in response to stresses in Deinococcus radiodurans (Yang et al 2016). This Grampositive bacterium is characterized by its efficient DNA repair ability and extreme stress resistance (Makarova et al 2001) and generally considered to be an ideal model organism for studying bacterial resistance mechanisms under various stress conditions.…”

The Cyclic AMP Receptor Protein Regulates Quorum Sensing and Global Gene Expression in Yersinia pestis During Planktonic Growth and Growth in Biofilms

“…While known for its role during catabolite repression and regulation of the lac operon, it is now appreciated that Crp regulates expression of other genes, including factors important during infection to connect changes in glucose availability to regulation of bacterial behaviors. Across γ-proteobacteria, Crp regulates biofilm formation (12,13), capsule production (14), the DNA damage response (15), toxin production (16,17), luminescence (18), and iron acquisition (19).…”

DdrI, a cAMP Receptor Protein Family Member, Acts as a Major Regulator for Adaptation of Deinococcus radiodurans to Various Stresses

“…We have recently demonstrated that inactivation of ddrI by transposon insertion sensitizes D. radiodurans to gamma and UV irradiation, mitomycin C (MMC), and H 2 O 2 (13). Yang et al confirmed that a deletion of the ddrI gene sensitizes cells to these harmful conditions, suggesting an important role of DdrI in the cellular response of D. radiodurans to DNA damage and oxidative stress (26). Moreover, the absence of DdrI results in slow bacterial growth (26).…”

“…Yang et al confirmed that a deletion of the ddrI gene sensitizes cells to these harmful conditions, suggesting an important role of DdrI in the cellular response of D. radiodurans to DNA damage and oxidative stress (26). Moreover, the absence of DdrI results in slow bacterial growth (26). The transcription of ddrI is induced by the response regulator DrRRA following gamma irradiation, and purified DrRRA binds to the ddrI promoter region (25).…”

“…The transcription of ddrI is induced by the response regulator DrRRA following gamma irradiation, and purified DrRRA binds to the ddrI promoter region (25). The DdrI protein exhibits typical features of the transcription factors belonging to the cAMP receptor protein (CRP) family, including an effector cyclic nucleotide monophosphate (cNMP)-binding domain at the N-terminal end, and a helix-turn-helix (HTH) DNA-binding domain at the C-terminal end (26). In E. coli, the expression of several dozen genes is regulated by CRP, including many genes involved in central carbon metabolism and transport of various metabolites (27).…”