Altered adherence properties of a Streptococcus gordonii hppA (oligopeptide permease) mutant result from transcriptional effects on cshA adhesin gene expression

• Published in: Microbiology (Society for General Microbiology) 1998-01, Vol.144 (1), p.127-136
• Main Authors: McNab, Roderick, Jenkinson, Howard F
• Format: Article
• Language: English
• Subjects: ATP-Binding Cassette Transporters - genetics; ATP-Binding Cassette Transporters - metabolism; Bacterial Adhesion - genetics; Bacterial Proteins - biosynthesis; Bacteriology; Base Sequence; Biological and medical sciences; Carrier Proteins - genetics; Carrier Proteins - metabolism; Chloramphenicol O-Acetyltransferase; Cloning, Molecular; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Bacterial; Genotype; Kinetics; Lipoproteins - genetics; Lipoproteins - metabolism; Membrane Proteins; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; Microbiology; Molecular Sequence Data; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Promoter Regions, Genetic; Recombinant Fusion Proteins - biosynthesis; Streptococcus - genetics; Streptococcus - physiology; Streptococcus gordonii; Transcription, Genetic
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-144-1-127

Molecular Oral Biology Laboratory, Department of Oral Biology and Oral Pathology, University of Otago, PO Box 647, Dunedin, New Zealand ABSTRACT Summary: Cell-surface polypeptide CshA (259 kDa) mediates multiple adherence interactions of Streptococcus gordonii. By generating a chromosomal cshA promoter ( p-cshA)-cat gene fusion and measuring both CAT enzyme activity and cat mRNA levels, it was shown that cshA is expressed maximally in cells in the late exponential phase of growth in batch culture. The expression of CAT enzyme activity from the p-cshA-cat promoter fusion was 28% decreased in early stationary phase cell extracts of mutant strain OB528 in which the hppA (oligopeptide-binding lipoprotein) gene was insertionally inactivated. This effect was correlated with proportionally reduced cell-surface expression of CshA protein and with impaired adherence of hppA mutant cells to cells of an oral Actinomyces naeslundii strain. cshA promoter activity was enhanced in streptococcal cells that were incubated in conditioned culture medium as opposed to fresh medium, but this did not occur in an hppA genetic background. It is suggested that HppA is necessary for the response of cells to an extracellular factor that modulates cshA transcription, and hence affects cell-surface CshA expression and streptococcal cell adherence properties. Author for correspondence: Howard F. Jenkinson. Tel: + 44 117 928 4304. Fax: [phone]. e-mail: [e-mail] Keywords: streptococcal cell adhesion, cell-surface proteins, oligopeptide permease, promoter activity, Streptococcus gordonii Present address: Department of Microbiology, Eastman Dental Institute, 256 Gray's Inn Road, London WC1X 8LD, UK. Present address: Department of Oral and Dental Science, University of Bristol, Dental Hospital and School, Lower Maudlin Street, Bristol BS1 2LY, UK.