Different roles of EIIABMan and EIIGlc in regulation of energy metabolism, biofilm development, and competence in Streptococcus mutans.
The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is the major carbohydrate transport system in oral streptococci. The mannose-PTS of Streptococcus mutans, which transports mannose and glucose, is involved in carbon catabolite repression (CCR) and regulates the expression of known virulence genes. In this study, we investigated the role of EII(Glc) and EIIAB(Man) in sugar metabolism, gene regulation, biofilm formation, and competence. The results demonstrate that the inactivation of ptsG, encoding a putative EII(Glc), did not lead to major changes in sugar metabolism or affect the phenotypes of interest. However, the loss of EII(Glc) was shown to have a significant impact on the proteome and to affect the expression of a known virulence factor, fructan hydrolase (fruA). JAM1, a mutant strain lacking EIIAB(Man), had an impaired capacity to form biofilms in the presence of glucose and displayed a decreased ability to be transformed with exogenous DNA. Also, the lactose- and cellobiose-PTSs were positively and negatively regulated by EIIAB(Man), respectively. Microarrays were used to investigate the profound phenotypic changes displayed by JAM1, revealing that EIIAB(Man) of S. mutans has a key regulatory role in energy metabolism, possibly by sensing the energy levels of the cells or the carbohydrate availability and, in response, regulating the activity of transcription factors and carbohydrate transporters.
Abranches
Jacqueline
J
Department of Oral Biology, University of Florida College of Dentistry, P.O. Box 100424, Gainesville, FL 32610, USA.
Candella
Melissa M
MM
Wen
Zezhang T
ZT
Baker
Henry V
HV
Burne
Robert A
RA
D018441:Biofilms / Q000254:growth & development*; D001692:Biological Transport; D017931:DNA Primers; D004734:Energy Metabolism; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D013295:Streptococcus mutans / Q000235:genetics / Q000254:growth & development / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D017931:DNA Primers; D014157:Transcription Factors; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; D005947:Glucose; D008358:Mannose