The proline residue at position 319 of BvgS is essential for BvgAS activation in Bordetella pertussis.
Bordetella pertussis is the etiological agent of pertussis and produces various virulence factors, including pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (PRN), most of which are positively regulated by the BvgAS two-component sensory transduction system. Here, we describe a B. pertussis isolate not expressing PT, FHA and PRN recovered from a pertussis patient. Sequencing revealed that the bvgS gene of this isolate contains a spontaneous mutation (C>A at position 955) causing the proline residue at position 319 of the BvgS protein to be substituted by threonine. Moreover, loss of PT, FHA and PRN expression was completely restored by complementation with a wild-type bvgAS locus, indicating that this non-synonymous substitution in bvgS leads to impaired BvgS function. Our findings indicate that the proline residue at position 319 in this protein plays an essential role in activation of the BvgAS system and, therefore, subsequent expression of Bvg-regulated virulence factors in B. pertussis.
Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo 208-0011, Japan.
Yukihiro
Y
Hiramatsu
Department of Microbiology, Miyazaki Prefectural Institute for Public Health and Environment, Miyazaki 880-0017, Japan.
Shuji
S
Yoshino
Department of Pediatrics, Miyazaki Prefectural Miyazaki Hospital, Miyazaki 880-0017, Japan.
Yoshiko
Y
Yamamura
Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo 208-0011, Japan.
Nao
N
Otsuka
Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo 208-0011, Japan.
Keigo
K
Shibayama
Graduate School of Infection Control Sciences, Kitasato University, Tokyo 108-8641, Japan.
Mineo
M
Watanabe
Department of Bacteriology II, National Institute of Infectious Diseases, Tokyo 208-0011, Japan.
Kazunari
K
Kamachi
D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001886:Bordetella pertussis / Q000502:physiology*; D003062:Codon; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D009154:Mutation; D011392:Proline / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; D003062:Codon; D014157:Transcription Factors; C080662:bvgS protein, Bordetella pertussis; D011392:Proline
Bordetella pertussis; Bvg-regulated virulence factors; BvgS; proline; spontaneous mutation