TY - JOUR
T1 - Functional interplay between the Yersinia pseudotuberculosis YpsRI and YtbRI quorum sensing systems modulates swimming motility by controlling expression of flhDC and fliA
AU - Atkinson, Steve
AU - Chang, Chien-Yi
AU - Patrick, Hannah L.
AU - Buckley, Catherine M F
AU - Wang, Yao
AU - Sockett, R. Elizabeth
AU - Cámara, Miguel
AU - Williams, Paul
PY - 2008/7
Y1 - 2008/7
N2 - Quorum sensing (QS) in Yersinia pseudotuberculosis involves two pairs of LuxRI orthologues (YpsRI and YtbRI) and multiple N-acylhomoserine lactones (AHLs). In a ypsI/ytbI mutant, AHL synthesis was abolished, unaffected in a ypsR/ytbR double mutant and substantially reduced in a ypsI/ytbR mutant, indicating that neither YpsR nor YtbR is essential for AHL synthesis. To determine the interrelationship between YpsRI and YtbRI we constructed chromosomal lux-promoter fusions to ypsR, ypsI, ytbR and ytbI and examined their expression in each of the QS mutant backgrounds. The YpsRI system negatively autoregulates itself but positively regulates the expression of the ytbRI system whereas the ytbRI system is positively autoregulated but only at the level of ytbI expression. YtbRI does not control expression of ypsR or ypsI. This hierarchical QS system controls swimming motility via regulation of flhDC and fliA. The AHLs synthesized via YtbI play a dual role, activating flhDC, in conjunction with YpsR but repressing fliA in conjunction with YtbR and YpsR. In liquid and plate assays, the early onset of motility observed in ypsR and ypsI mutants was abolished in ytbI, ytbR ypsI/ytbI, ypsR/ytbR mutants, indicating that QS regulates motility both positively (via YtbRI) and negatively (via YpsRI).
AB - Quorum sensing (QS) in Yersinia pseudotuberculosis involves two pairs of LuxRI orthologues (YpsRI and YtbRI) and multiple N-acylhomoserine lactones (AHLs). In a ypsI/ytbI mutant, AHL synthesis was abolished, unaffected in a ypsR/ytbR double mutant and substantially reduced in a ypsI/ytbR mutant, indicating that neither YpsR nor YtbR is essential for AHL synthesis. To determine the interrelationship between YpsRI and YtbRI we constructed chromosomal lux-promoter fusions to ypsR, ypsI, ytbR and ytbI and examined their expression in each of the QS mutant backgrounds. The YpsRI system negatively autoregulates itself but positively regulates the expression of the ytbRI system whereas the ytbRI system is positively autoregulated but only at the level of ytbI expression. YtbRI does not control expression of ypsR or ypsI. This hierarchical QS system controls swimming motility via regulation of flhDC and fliA. The AHLs synthesized via YtbI play a dual role, activating flhDC, in conjunction with YpsR but repressing fliA in conjunction with YtbR and YpsR. In liquid and plate assays, the early onset of motility observed in ypsR and ypsI mutants was abolished in ytbI, ytbR ypsI/ytbI, ypsR/ytbR mutants, indicating that QS regulates motility both positively (via YtbRI) and negatively (via YpsRI).
UR - http://www.scopus.com/inward/record.url?scp=45149125986&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2958.2008.06268.x
DO - 10.1111/j.1365-2958.2008.06268.x
M3 - Article
C2 - 18466299
AN - SCOPUS:45149125986
SN - 0950-382X
VL - 69
SP - 137
EP - 151
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 1
ER -