Fur is required for the activation of virulence gene expression through the induction of the sae regulatory system in Staphylococcus aureus.
Our previous studies showed that both Sae and Fur are required for the induction of eap and emp expression in low iron. In this study, we show that expression of sae is also iron-regulated, as sae expression is activated by Fur in low iron. We also demonstrate that both Fur and Sae are required for full induction of the oxidative stress response and expression of non-covalently bound surface proteins in low-iron growth conditions. In addition, Sae is required for the induced expression of the important virulence factors isdA and isdB in low iron. Our studies also indicate that Fur is required for the induced expression of the global regulators Agr and Rot in low iron and a number of extracellular virulence factors such as the haemolysins which are also Sae- and Agr-regulated. Hence, we show that Fur is central to a complex regulatory network that is required for the induced expression of a number of important S. aureus virulence determinants in low iron.
Johnson
Miranda
M
Dept. of Genetics, University of Leicester, University Road, Leicester LE1 7RH, UK.
Sengupta
Mrittika
M
Purves
Joanne
J
Tarrant
Emma
E
Williams
Peter H
PH
Cockayne
Alan
A
Muthaiyan
Arunachalam
A
Stephenson
Robert
R
Ledala
Nagender
N
Wilkinson
Brian J
BJ
Jayaswal
Radheshyam K
RK
Morrissey
Julie A
JA
D001426:Bacterial Proteins / Q000378:metabolism*; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D007501:Iron / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000472:pathogenicity*; D014157:Transcription Factors; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis*
D001426:Bacterial Proteins; D012097:Repressor Proteins; C433805:SaeR protein, Staphylococcus aureus; D014157:Transcription Factors; D037521:Virulence Factors; C068477:ferric uptake regulating proteins, bacterial; D007501:Iron; D011494:Protein Kinases; C527351:SaeS protein, Staphylococcus aureus