TY - JOUR
T1 - New insights into Staphylococcus aureus stress tolerance and virulence regulation from an analysis of the role of the ClpP protease in the strains Newman, COL, and SA564
AU - Frees, Dorte
AU - Andersen, Julie Hove
AU - Hemmingsen, Lene
AU - Koskenniemi, Kerttu
AU - Bæk, Kristoffer Torbjørn
AU - Muhammed, Musemma Kedir
AU - Gudeta, Dereje Dadi
AU - Nyman, Tuula A.
AU - Sukura, Antti
AU - Varmanen, Pekka
AU - Savijoki, Kirsi
PY - 2012/1/1
Y1 - 2012/1/1
N2 - In Staphylococcus aureus, ClpP proteases were previously shown to be essential for virulence and stress tolerance in strains derived from NCTC8325. Because these strains exhibit a severely reduced activity of the alternative sigma factor, SigB, we here reassessed the role of ClpP in SigB-proficient clinical strains. To this end, clpP was deleted in strains COL, Newman, and SA564, and the strains were characterized phenotypically. The proteomic changes accomplished by the clpP deletion in the different strains were analyzed using the 2-D DIGE technique. The proteomic analyses revealed mostly conserved changes in the protein profiles of the ClpP-deficient strains. Among the strain-specific changes were the up-regulation of prophage proteins that coincided with an increased spontaneous release of prophages and the relatively poorer growth of the clpP mutants in some strain backgrounds. Interestingly, the effect of ClpP on the expression of selected virulence genes was strain-dependent despite the fact that the expression of the global virulence regulators RNAIII, mgrA, sarZ, sarR, and arlRS was similarly changed in all clpP mutants. ClpP affected the expression of sarS in a strain-dependent manner, and we propose that the differential expression of sarS is central to the strain-dependent effect of ClpP on the expression of virulence genes.
AB - In Staphylococcus aureus, ClpP proteases were previously shown to be essential for virulence and stress tolerance in strains derived from NCTC8325. Because these strains exhibit a severely reduced activity of the alternative sigma factor, SigB, we here reassessed the role of ClpP in SigB-proficient clinical strains. To this end, clpP was deleted in strains COL, Newman, and SA564, and the strains were characterized phenotypically. The proteomic changes accomplished by the clpP deletion in the different strains were analyzed using the 2-D DIGE technique. The proteomic analyses revealed mostly conserved changes in the protein profiles of the ClpP-deficient strains. Among the strain-specific changes were the up-regulation of prophage proteins that coincided with an increased spontaneous release of prophages and the relatively poorer growth of the clpP mutants in some strain backgrounds. Interestingly, the effect of ClpP on the expression of selected virulence genes was strain-dependent despite the fact that the expression of the global virulence regulators RNAIII, mgrA, sarZ, sarR, and arlRS was similarly changed in all clpP mutants. ClpP affected the expression of sarS in a strain-dependent manner, and we propose that the differential expression of sarS is central to the strain-dependent effect of ClpP on the expression of virulence genes.
U2 - 10.1021/pr200956s
DO - 10.1021/pr200956s
M3 - Journal article
C2 - 22112206
SN - 1535-3893
VL - 11
SP - 95
EP - 108
JO - Journal of Proteome Research
JF - Journal of Proteome Research
IS - 1
ER -