title: Proteus mirabilis glutathione S-transferase B1-1 is involved in protective mechanisms against oxidative and chemical stresses.
abstract: We investigated the effects of several xenobiotics, including antimicrobial agents and general stress factors such as starvation, heat and osmotic shock, on the modulation of expression of Proteus mirabilis glutathione S-transferase B1-1 (PmGST B1-1). The level of expression of PmGST B1-1 was established by both Western- and Northern-blot experiments. Our results show that several compounds can modulate expression of PmGST B1-1. The level of PmGST B1-1 increased when bacterial cells were exposed to a variety of stresses such as 1-chloro-2,4-dinitrobenzene, H(2)O(2), fosfomycin or tetracycline. A knock-out gst B gene was also constructed using the suicide vector pKNOCKlox-Ap. Successful inactivation of the wild-type gene was confirmed by PCR, DNA sequence analysis and Western blotting. Under normal culture conditions, this mutant was viable and displayed no significant phenotypic differences compared with the wild-type. However, viability tests revealed that the null mutant was more sensitive to oxidative stress in the form of H(2)O(2) and to several antimicrobial drugs when compared with the wild-type. These results suggest that PmGST B1-1 has an active role in the protection against oxidative stress generated by H(2)O(2) and it appears to be involved in the detoxification of antimicrobial agents.
authors.affiliation: Dipartimento di Scienze Biomediche, Università G. d'Annunzio, Via dei Vestini 31, I-66013 Chieti, Italy. n.allocati@dsb.unich.it
authors.forename: Nerino
authors.initials: N
authors.lastname: Allocati
authors.forename: Bartolo
authors.initials: B
authors.lastname: Favaloro
authors.forename: Michele
authors.initials: M
authors.lastname: Masulli
authors.forename: Mikhail F
authors.initials: MF
authors.lastname: Alexeyev
authors.forename: Carmine
authors.initials: C
authors.lastname: Di Ilio
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D005982:Glutathione Transferase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000494:pharmacology; D007700:Kinetics; D018384:Oxidative Stress / Q000502:physiology*; D016133:Polymerase Chain Reaction; D011513:Proteus mirabilis / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D012333:RNA, Messenger / Q000235:genetics; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic; D015262:Xenobiotics / Q000494:pharmacology
chemical_list: D017931:DNA Primers; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015262:Xenobiotics; D006861:Hydrogen Peroxide; D005982:Glutathione Transferase