The QseEF Two-Component System-GlmY Small RNA Regulatory Pathway Controls Swarming in Uropathogenic

Bacterial sensing of environmental signals through the two-component system (TCS) plays a key role in modulating virulence. In the search for the host hormone-sensing TCS, we identified a conserved locus following , a small RNA (sRNA) gene in uropathogenic . Genes of constitute an operon, and QseF binding sites were found in the promoter region. Deletion of or resulted in reduced swarming motility and swarming-related phenotypes relative to the wild-type and the respective complemented strains. The mutant had decreased promoter activity. Both and mutants exhibited decreased promoter activity and mRNA level, while increased mRNA level was observed in both mutants. Prediction by TargetRNA2 revealed as the target of GlmY. Then, construction of the translational fusions containing various lengths of 5'UTR for reporter assay and site-directed mutagenesis were performed to investigate the -GlmY interaction in activation. Notably, loss of reduced the mRNA level, and urea could inhibit swarming in a QseF-dependent manner. Altogether, this is the first report elucidating the underlying mechanisms for modulation of swarming motility by a QseEF-regulated sRNA GlmY, involving expression of , and in uropathogenic .