title: Identification of a two-component VirR/VirS regulon in Clostridium perfringens.
abstract: Clostridium perfringens, a Gram-positive anaerobic pathogen, is a causative agent of human gas gangrene that leads to severe rapid tissue destruction and can cause death within hours unless treated immediately. Production of several toxins is known to be controlled by the two-component VirR/VirS system involving a regulatory RNA (VR-RNA) in C. perfringens. To elucidate the precise regulatory network governed by VirR/VirS and VR-RNA, a series of microarray screening using VirR/VirS and VR-RNA-deficient mutants was performed. Finally, by qRT-PCR analysis, 147 genes (30 single genes and 21 putative operons) were confirmed to be under the control of the VirR/VirS-VR-RNA regulatory cascade. Several virulence-related genes for alpha-toxin, kappa-toxin, hyaluronidases, sialidase, and capsular polysaccharide synthesis were found. Furthermore, some genes for catalytic enzymes, various genes for transporters, and many genes for energy metabolism were also found to be controlled by the cascade. Our data indicate that the VirR/VirS-VR-RNA system is a global gene regulator that might control multiple cellular functions to survive and multiply in the host, which would turn out to be a lethal flesh-eating infection.
authors.affiliation: Department of Bacteriology, Graduate School of Medical Science, Kanawaza University, 13-1 Takara-Machi Kanazawa, Ishikawa 920-8640, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Ohtani
authors.forename: Hideki
authors.initials: H
authors.lastname: Hirakawa
authors.forename: Kousuke
authors.initials: K
authors.lastname: Tashiro
authors.forename: Satoko
authors.initials: S
authors.lastname: Yoshizawa
authors.forename: Satoru
authors.initials: S
authors.lastname: Kuhara
authors.forename: Tohru
authors.initials: T
authors.lastname: Shimizu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D003016:Clostridium perfringens / Q000235:genetics* / Q000472:pathogenicity; D005738:Gas Gangrene / Q000382:microbiology; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012329:RNA, Bacterial / Q000235:genetics; D018085:Regulon / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D012329:RNA, Bacterial; D014157:Transcription Factors; D037521:Virulence Factors