A novel feature of the multistep phosphorelay in Escherichia coli: a revised model of the RcsC → YojN → RcsB signalling pathway implicated in capsular synthesis and swarming behaviour

Abstract

In this study, we re‐investigated the previously characterized RcsC (sensor His‐kinase) → RcsB (response regulator) phosphorelay system that is involved in the regulation of capsular polysaccharide synthesis in Escherichia coli. The previously proposed model hypothesized the occurrence of a direct phosphotransfer from RcsC to RcsB in response to an unknown external stimulus. As judged from the current general view as to the His → Asp phosphorelay, this RcsC → RcsB framework is somewhat puzzling, because RcsC appears to contain both a His‐kinase domain and a receiver domain, but not a histidine (His)‐containing phosphotransmitter domain (e.g. HPt domain). We thus suspected that an as yet unknown mechanism might be underlying in this particular His → Asp phosphorelay system. Here, we provide several lines of in vivo and in vitro evidence that a novel and unique His‐containing phosphotransmitter (named YojN) is essential for this signalling system. A revised model is proposed in which the multistep RcsC → YojN → RcsB phosphorelay is implicated. It was also demonstrated that this complex signalling system is somehow involved in the modulation of a characteristic behaviour of E. coli cells during colony formation on the surface of agar plates, namely swarming.

The importance of the Rcs phosphorelay in the survival and pathogenesis of the enteropathogenic yersiniae

“…In our study the rcsD : : Km mutants of both Y. enterocolitica strains showed reduced swarming motility, similar to Rcs mutants in Salmonella enterica serovar Typhimurium, but in contrast to mutants in Proteus and E. coli (Belas et al, 1998;Toguchi et al, 2000;Takeda et al, 2001). Neither of the Y. pseudotuberculosis strains was able to swarm, but disruption of the Rcs phosphorelay did affect the swimming motility of Y. pseudotuberculosis IP32953 by making it hypermotile.…”

Elevated levels of σ S inhibit biofilm formation in Escherichia coli: a role for the Rcs phosphorelay

“…Subsequently, the phosphoryl group is transferred to the HPt domain of RcsD and finally to the receiver domain of RcsB. Phospho-RcsB (RcsB-P) then binds to DNA and affects the expression of an extensive Rcs regulon Ferrières & Clarke, 2003;Hagiwara et al, 2003;Takeda et al, 2001). In addition, three accessory proteins, RcsA, RcsF and YrfF (IgaA), participate in the modulation of the inputs and outputs of this phosphorelay Meberg et al, 2001;Stout et al, 1991;Tierrez & Garcia-del Portillo, 2004).…”

The glutamate-dependent acid resistance system in Escherichia coli: essential and dual role of the His–Asp phosphorelay RcsCDB/AF

“…Following an intramolecular phosphorylation step, the sensor RcsC transfers the phosphoryl group to its cognate response regulator RcsB, via a histidine-containing phosphotransmitter (Hpt) domain protein, RcsD/YojN (Takeda et al, 2001). The Rcs system is activated by alterations of the envelope (for reviews see Majdalani & Gottesman, 2005;Francez-Charlot et al, 2005a).…”