title: Role of catabolite control protein A in the regulation of intermedilysin production by Streptococcus intermedius.
abstract: Streptococcus intermedius is an opportunistic pathogen of humans that causes purulent infections, including brain and liver abscesses. This pathogen secretes a human-specific cytolysin, intermedilysin, which has been recognized as a major virulence factor. However, most of the expressional control mechanisms of ily are still unknown. To determine these mechanisms, we analyzed the nucleotide sequence of the ily promoter region. We found a highly homologous region to the catabolite-repressible element (cre) in the ily promoter region and observed a considerable decrease in the amount of secreted intermedilysin when cells were grown in a culture medium containing high concentrations of glucose/utilizable carbohydrates. Disruption of the ccpA gene, which encodes catabolite control protein A, did not induce catabolite repression of ily by glucose/utilizable carbohydrates. In cre mutants, catabolite repression of ily was partially restored, and purified catabolite control protein A bound to an oligonucleotide containing the cre consensus sequence in the ily promoter region. In addition, a prolonged lag phase and slower doubling time of the ccpA mutant cells were observed. Our data show that S. intermedius can modulate ily expression and growth rate through catabolite control protein A-mediated monitoring of the extracellular glucose/utilizable carbohydrate concentration.
authors.affiliation: Department of Biological Science and Technology, Institute of Technology and Science, The University of Tokushima Graduate School, Minami-josanjima-cho, Tokushima 770-8506, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Tomoyasu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tabata
authors.forename: Riki
authors.initials: R
authors.lastname: Hiroshima
authors.forename: Hidenori
authors.initials: H
authors.lastname: Imaki
authors.forename: Sachiko
authors.initials: S
authors.lastname: Masuda
authors.forename: Robert A
authors.initials: RA
authors.lastname: Whiley
authors.forename: Joseph
authors.initials: J
authors.lastname: Aduse-Opoku
authors.forename: Ken
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hiramatsu
authors.forename: Hideaki
authors.initials: H
authors.lastname: Nagamune
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D001430:Bacteriocins / Q000096:biosynthesis*; D003470:Culture Media; D024202:Electrophoretic Mobility Shift Assay; D006801:Humans; D019426:Integrases / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology*; D034367:Streptococcus intermedius / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D003470:Culture Media; D012097:Repressor Proteins; C069286:catabolite control proteins, bacteria; C403910:intermedilysin protein, Streptococcus intermedius; C045073:Cre recombinase; D019426:Integrases