Adaptation to the host environment: regulation of the SPI1 type III secretion system in Salmonella enterica serovar Typhimurium.
Salmonella enterica invades the intestinal epithelium of the host using a type III secretion system encoded on Salmonella pathogenicity island 1 (SPI1). The bacteria integrate environmental signals from a variety of global regulatory systems to precisely induce transcription of SPI1. The regulatory circuit converges on expression of HilA, which directly regulates transcription of the SPI1 apparatus genes. Transcription of hilA is controlled by a complex feed-forward loop. Regulatory signals feed into the system through post-transcriptional and post-translational control of HilD, which in turn activates HilC and RtsA. These three regulators act in concert to control hilA transcription. The system acts as a switch, ensuring that SPI1 is fully on at the appropriate time.
Ellermeier
Jeremy R
JR
Department of Microbiology, University of Illinois, B103 Chemical and Life Sciences Laboratory, Urbana, IL 61801, USA.
Slauch
James M
JM
D000222:Adaptation, Physiological; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D044404:Genomic Islands / Q000235:genetics*; D021381:Protein Transport; D012486:Salmonella typhimurium / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D015534:Trans-Activators / Q000096:biosynthesis; D014157:Transcription Factors / Q000096:biosynthesis; D014158:Transcription, Genetic; D014774:Virulence / Q000235:genetics
D001426:Bacterial Proteins; C102236:HilA protein, Salmonella; C119659:HilC protein, Salmonella typhimurium; C119660:HilD protein, Salmonella typhimurium; D015534:Trans-Activators; D014157:Transcription Factors