title: Adherence and fibronectin binding are environmentally regulated in the group A streptococci.
abstract: The ability of the pathogenic Gram-positive bacterium Streptococcus pyogenes (group A streptococcus) to bind fibronectin and adhere to respiratory epithelial cells is dependent on a surface protein called protein F. In this study, we have examined the regulation of expression of protein F and have shown that it is environmentally regulated in response to alterations in atmosphere. In six recent clinical isolates expression of protein F was repressed during growth under reduced concentrations of O2. Expression in an anaerobic environment was induced by both superoxide-generating and redox-altering reagents. However, regulation did not involve mry, a gene that controls expression of several streptococcal surface proteins. Protein F was constitutively expressed in one of two laboratory-passaged strains analysed, and in a complementation analysis using an allele of the gene that encodes protein F (prtF) cloned from a regulated strain and expressed in a constitutive strain, the constitutive phenotype was shown to be dominant in trans. Regulation, as monitored by fusion of prtF to a promoterless chloramphenicol acetyltransferase gene, involved transcriptional control. Environmentally induced alterations in protein F expression affected the ability of the bacterium to adhere to epithelial cells, which suggests that the ability to regulate expression of protein F may be important during infection.
authors.affiliation: Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110-1093.
authors.forename: T
authors.initials: T
authors.lastname: VanHeyningen
authors.forename: G
authors.initials: G
authors.lastname: Fogg
authors.forename: D
authors.initials: D
authors.lastname: Yates
authors.forename: E
authors.initials: E
authors.lastname: Hanski
authors.forename: M
authors.initials: M
authors.lastname: Caparon
mesh_terms: D001422:Bacterial Adhesion; D002478:Cells, Cultured; D015500:Chloramphenicol O-Acetyltransferase / Q000032:analysis / Q000096:biosynthesis; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D004848:Epithelium / Q000382:microbiology / Q000502:physiology; D005353:Fibronectins / Q000378:metabolism*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D006801:Humans; D010957:Plasmids; D011485:Protein Binding; D017469:Receptors, Fibronectin / Q000096:biosynthesis* / Q000378:metabolism; D012143:Respiratory Physiological Phenomena; D012137:Respiratory System / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D013481:Superoxides / Q000378:metabolism; D014169:Transformation, Bacterial
chemical_list: D004269:DNA, Bacterial; D005353:Fibronectins; D017469:Receptors, Fibronectin; D013481:Superoxides; D015500:Chloramphenicol O-Acetyltransferase