Clp-dependent proteolysis of the LexA N-terminal domain in Staphylococcus aureus

Cohn, Marianne Thorup; Kjelgaard, Peter; Frees, Dorte; Penadés, José R.; Ingmer, Hanne

doi:10.1099/mic.0.043794-0

Cited by 27 publications

(46 citation statements)

References 43 publications

(59 reference statements)

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“…We also identified the clpP gene encoding the proteolytic subunit of the ClpXP two-component protease to be more susceptible to ciprofloxacin, corroborating a study in P. aeruginosa (Fernández et al, 2012). A possible link between clpP and ciprofloxacin susceptibility is that clpP has been shown to interfere with activation of the SOS DNA-damage response (Cohn et al, 2011). Additionally, inactivation of several hypothetical genes ( SAUSA300_1789 and SAUSA300_2311 ) also conferred a fourfold or greater sensitization to ciprofloxacin relative to the WT strain.…”

Section: Resultsmentioning

confidence: 99%

Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

et al. 2016

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The emergence of antimicrobial resistance severely threatens our ability to treat bacterial infections. While acquired resistance has received considerable attention, relatively little is known of intrinsic resistance that allows bacteria to naturally withstand antimicrobials. Gene products that confer intrinsic resistance to antimicrobial agents may be explored for alternative antimicrobial therapies, by potentiating the efficacy of existing antimicrobials. In this study, we identified the intrinsic resistome to a broad spectrum of antimicrobials in the human pathogen, Staphylococcus aureus. We screened the Nebraska Transposon Mutant Library of 1920 single-gene inactivations in S. aureus strain JE2, for increased susceptibility to the anti-staphylococcal antimicrobials (ciprofloxacin, oxacillin, linezolid, fosfomycin, daptomycin, mupirocin, vancomycin, and gentamicin). Sixty-eight mutants were confirmed by E-test to display at least twofold increased susceptibility to one or more antimicrobial agents. The majority of the identified genes have not previously been associated with antimicrobial susceptibility in S. aureus. For example, inactivation of genes encoding for subunits of the ATP synthase, atpA, atpB, atpG and atpH, reduced the minimum inhibitory concentration (MIC) of gentamicin 16-fold. To elucidate the potential of the screen, we examined treatment efficacy in the Galleria mellonella infection model. Gentamicin efficacy was significantly improved, when treating larvae infected with the atpA mutant compared to wild type cells with gentamicin at a clinically relevant concentration. Our results demonstrate that many gene products contribute to the intrinsic antimicrobial resistance of S. aureus. Knowledge of these intrinsic resistance determinants provides alternative targets for compounds that may potentiate the efficacy of existing antimicrobial agents against this important pathogen.

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Section: Resultsmentioning

confidence: 99%

Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

et al. 2016

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“…In S. aureus, very few substrates of ClpC/XP have been identified, although ClpCP has been implicated in degradation of antitoxins (10). Cohn et al (11) showed that ClpXP, and to a lesser extent ClpCP, are involved in regulating the SOS response and thus affect expression of a subset of SOS regulon genes by degrading the LexA N-terminal domain after autocleavage of LexA. E618A) mutation, referred to as clpC trap , was constructed via overlapping PCR in two steps, using the primers listed in Table 2.…”

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confidence: 99%

Trapping and Identification of Cellular Substrates of the Staphylococcus aureus ClpC Chaperone

2013

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ClpC is an ATP-dependent Hsp100/Clp chaperone involved in protein quality control in low-GC Gram-positive bacteria. Previously, we found that ClpC affected the expression of a large number of genes, including capsule genes in Staphylococcus aureus. Here we constructed a His-tagged ClpC variant (ClpC trap ) with mutations within the Walker B motifs to identify the direct substrates of ClpC by copurification with ClpC trap followed by gel electrophoresis combined with liquid chromatography-tandem mass spectrometry proteomics. We identified a total of 103 proteins that are potential substrates of ClpC in strain Newman. The direct protein-protein interaction of ClpC with a subset of the captured proteins was verified in a bacterial two-hybrid system. The captured proteins could be grouped into various functional categories, but most were related to proteins involved in the stress response. Several known ClpC substrates were captured, including ClpP, TrfA/MecA, ClpB, DnaK, DnaJ, GroL, RecA, and CodY, supporting the validity of our approach. Our results also revealed many new ClpC substrates, including AgrA, CcpA, RsbW, MurG, FtsA, SrtA, Rex, Atl, ClfA, and SbcC. Analysis of capsule production showed that three of the captured proteins, which were not previously known to be transcriptional regulators, did affect capsule production.

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“…In S. aureus, the ClpPX as well as the ClpPC proteases contribute to degradation of LexA autocleavage products (Cohn et al, 2011). Therefore, the low level of persisters observed in clpP mutant cells may be attributed to a decrease in overall stress response, and the differences among antibiotics may be explained through the antibiotics, specific target and degree of stressors (Kim et al, 2011).…”

Section: Effect Of Clpp Deletion On Persister Cell Number After Antibmentioning

confidence: 99%

Effect of clpP and clpC deletion on persister cell number in Staphylococcus aureus

Springer

Singh

Cheung

et al. 2016

Journal of Medical Microbiology

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Staphylococcus aureus is responsible for a wide variety of infections that include superficial skin and soft tissue infections, septicaemia, central nervous system infections, endocarditis, osteomyelitis and pneumonia. Others have demonstrated the importance of toxin-antitoxin (TA) modules in the formation of persisters and the role of the Clp proteolytic system in the regulation of these TA modules. This study was conducted to determine the effect of clpP and clpC deletion on S. aureus persister cell numbers following antibiotic treatment. Deletion of clpP resulted in a significant decrease in persister cells following treatment with oxacillin and erythromycin but not with levofloxacin and daptomycin. Deletion of clpC resulted in a decrease in persister cells following treatment with oxacillin. These differences were dependent on the antibiotic class and the CFU ml À1 in which the cells were treated. Persister revival assays for all the bacterial strains in these studies demonstrated a significant delay in resumption of growth characteristic of persister cells, indicating that the surviving organisms in this study were not likely due to spontaneous antibiotic resistance. Based on our results, ClpP and possibly ClpC play a role in persister cell formation or maintenance, and this effect is dependent on antibiotic class and the CFU ml À1 or the growth phase of the cells.

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Clp-dependent proteolysis of the LexA N-terminal domain in Staphylococcus aureus

Cited by 27 publications

References 43 publications

Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

Genome-Wide Identification of Antimicrobial Intrinsic Resistance Determinants in Staphylococcus aureus

Trapping and Identification of Cellular Substrates of the Staphylococcus aureus ClpC Chaperone

Effect of clpP and clpC deletion on persister cell number in Staphylococcus aureus

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