Delineation of the Salmonella enterica serovar Typhimurium HilA regulon through genome-wide location and transcript analysis.
The Salmonella enterica serovar Typhimurium HilA protein is the key regulator for the invasion of epithelial cells. By a combination of genome-wide location and transcript analysis, the HilA-dependent regulon has been delineated. Under invasion-inducing conditions, HilA binds to most of the known target genes and a number of new target genes. The sopB, sopE, and sopA genes, encoding effector proteins secreted by the type III secretion system on Salmonella pathogenicity island 1 (SPI-1), were identified as being both bound by HilA and differentially regulated in an HilA mutant. This suggests a cooperative role for HilA and InvF in the regulation of SPI-1-secreted effectors. Also, siiA, the first gene of SPI-4, is both bound by HilA and differentially regulated in an HilA mutant, thus linking this pathogenicity island to the invasion key regulator. Finally, the interactions of HilA with the SPI-2 secretion system gene ssaH and the flagellar gene flhD imply a repressor function for HilA under invasion-inducing conditions.
Thijs
Inge M V
IM
Centre of Microbial and Plant Genetics, K. U. Leuven, Kasteelpark Arenberg 20, 3001 Leuven, Belgium.
De Keersmaecker
Sigrid C J
SC
Fadda
Abeer
A
Engelen
Kristof
K
Zhao
Hui
H
McClelland
Michael
M
Marchal
Kathleen
K
Vanderleyden
Jos
J
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D015964:Gene Expression Regulation, Bacterial; D016680:Genome, Bacterial; D008957:Models, Genetic; D009154:Mutation; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic / Q000235:genetics; D011485:Protein Binding; D018085:Regulon / Q000235:genetics*; D012486:Salmonella typhimurium / Q000235:genetics* / Q000378:metabolism; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*
D001426:Bacterial Proteins; C102236:HilA protein, Salmonella; C103987:SopE protein, Salmonella; D015534:Trans-Activators; C060971:SopA protein, Bacteria; C489224:SopB protein, Salmonella