Regulation of virulence by environmental signals in group A streptococci: influence of osmolarity, temperature, gas exchange, and iron limitation on emm transcription.
Transcription of the gene encoding the antiphagocytic M protein (emm) of the group A streptococci has been shown to be regulated by CO2 (M. G. Caparon, R. T. Geist, J. Perez-Casal, and J. R. Scott, J. Bacteriol. 174:5693-5701, 1992). We tested the influence of additional environmental growth conditions on emm expression. Increased osmolarity, low temperature, growth with free exchange of gasses, or the restricted availability of iron resulted in decreased transcription from the emm promoter.
McIver
K S
KS
Department of Microbiology and Immunology, Emory University, Atlanta, Georgia 30322, USA.
Heath
A S
AS
Scott
J R
JR
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000235:genetics*; D002352:Carrier Proteins; D005740:Gases; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D013297:Streptococcus pyogenes / Q000235:genetics / Q000472:pathogenicity*; D013696:Temperature; D014158:Transcription, Genetic; D014882:Water-Electrolyte Balance
D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D005740:Gases; D012333:RNA, Messenger; C014689:streptococcal M protein; D007501:Iron