Phosphate flow in the chemotactic response system of Helicobacter pylori

Jiménez-Pearson, María-Antonieta; Delany, Isabel; Scarlato, Vincenzo; Beier, Dagmar

doi:10.1099/mic.0.28217-0

Cited by 57 publications

(70 citation statements)

References 45 publications

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“…We next tested whether CheW and CheV1 could each allosterically function to activate CheA autophosphorylation and to couple CheA to a chemoreceptor. These studies were done using an in vitro CheA phosphorylation assay similar to one used in previous studies (22,23). In this assay, purified CheA ± coupling protein and receptor are incubated in vitro with radioactive [γ -32 P]-ATP and the amount of phosphorylated CheA determined using phosphorimaging of SDS PAGE gels ( Fig.…”

Section: Chew and Chev1 Both Form Direct Interactions With Chea Andmentioning

confidence: 99%

Cooperation of two distinct coupling proteins creates chemosensory network connections

Abedrabbo

Castellon

Collins

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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Although it is appreciated that bacterial chemotaxis systems rely on coupling, also called scaffold, proteins to both connect input receptors with output kinases and build interkinase connections that allow signal amplification, it is not yet clear why many systems use more than one coupling protein. We examined the distinct functions for multiple coupling proteins in the bacterial chemotaxis system of Helicobacter pylori, which requires two nonredundant coupling proteins for chemotaxis: CheW and CheV1, a hybrid of a CheW and a phosphorylatable receiver domain. We report that CheV1 and CheW have largely redundant abilities to interact with chemoreceptors and the CheA kinase, and both similarly activated CheA’s kinase activity. We discovered, however, that they are not redundant for formation of the higher order chemoreceptor arrays that are known to form via CheA–CheW interactions. In support of this possibility, we found that CheW and CheV1 interact with each other and with CheA independent of the chemoreceptors. Therefore, it seems that some microbes have modified array formation to require CheW and CheV1. Our data suggest that multiple coupling proteins may be used to provide flexibility in the chemoreceptor array formation.

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Section: Chew and Chev1 Both Form Direct Interactions With Chea Andmentioning

confidence: 99%

Cooperation of two distinct coupling proteins creates chemosensory network connections

Abedrabbo

Castellon

Collins

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

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“…It is assumable that a similar mechanism could also exist in C. jejuni, but the phosphorylation status of Campylobacter-CheV is not finally clear [37]. CheV catalyses the dephosphorylation of CheA(Y), but the halftime of phosphorylated CheV in Epsilonproteobacteria seems to be remarkably short [41,67].…”

Section: Different Mechanisms Of Sensory Adaptationmentioning

confidence: 99%

“…It is not finally clear, which role this additional RR-domain plays in the function of CheAY. CheAY is able to phosphorylate its RR-domain but CheY seems to be the preferred substrate [41]. Otherwise, CheY can phos- phorylate CheAY at its RR-domain [41].…”

Section: Experimental Approachesmentioning

confidence: 99%

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Chemotaxis inCampylobacter Jejuni

Zautner

Tareen

Groß

et al. 2012

European Journal of Microbiology and Immunology

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“…Support for such a mechanism comes from CheV, a hybrid protein with an N-terminal CheW-like adaptor domain and a C-terminal response regulator domain known to be phosphorylated by CheA (22)(23)(24)(25). This protein is functionally similar to CheW and is believed to function in a separate, methylationindependent adaptation system (23,26).…”

mentioning

confidence: 99%

Attractant Binding Induces Distinct Structural Changes to the Polar and Lateral Signaling Clusters in Bacillus subtilis Chemotaxis

Wu¹,

Walukiewicz

Glekas

et al. 2011

Journal of Biological Chemistry

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Bacteria employ a modified two-component system for chemotaxis, where the receptors form ternary complexes with CheA histidine kinases and CheW adaptor proteins. These complexes are arranged in semi-ordered arrays clustered predominantly at the cell poles. The prevailing models assume that these arrays are static and reorganize only locally in response to attractant binding. Recent studies have shown, however, that these structures may in fact be much more fluid. We investigated the localization of the chemotaxis signaling arrays in Bacillus subtilis using immunofluorescence and live cell fluorescence microscopy. We found that the receptors were localized in clusters at the poles in most cells. However, when the cells were exposed to attractant, the number exhibiting polar clusters was reduced roughly 2-fold, whereas the number exhibiting lateral clusters distinct from the poles increased significantly. These changes in receptor clustering were reversible as polar localization was reestablished in adapted cells. We also investigated the dynamic localization of CheV, a hybrid protein consisting of an N-terminal CheW-like adaptor domain and a C-terminal response regulator domain that is known to be phosphorylated by CheA, using immunofluorescence. Interestingly, we found that CheV was localized predominantly at lateral clusters in unstimulated cells. However, upon exposure to attractant, CheV was found to be predominantly localized to the cell poles. Moreover, changes in CheV localization are phosphorylation-dependent. Collectively, these results suggest that the chemotaxis signaling arrays in B. subtilis are dynamic structures and that feedback loops involving phosphorylation may regulate the positioning of individual proteins.Many motile bacteria employ for chemotaxis a modified two-component system to sense and respond to chemicals, where the receptors form ternary complexes with the CheA histidine kinase and the CheW adaptor protein (1, 2). The clustering of these ternary complexes into semi-ordered hexagonal lattices has been documented in multiple species (3) and is presumably conserved in all chemotactic bacteria where the three proteins are found. These arrays are thought to amplify the response to attractant binding (4,5). A number of models have specifically proposed that cooperative interactions between the receptors within these arrays enable bacteria to sense small differences in the number of attractant-bound receptors over a wide range of concentrations (see Ref. 6).Multiple studies have investigated the structure and molecular determinants of these clusters (e.g. Refs. 7 and 8) along with their role in signal transduction. In Escherichia coli, the receptors form mixed trimers of receptor homodimers. These trimers are believed to form the basic building blocks for the larger clusters, which range in size from tens to thousands of receptors (9). These clusters are found predominantly at the cell poles, although they are also found along the lateral length of the cell. Attractant binding, which inhibi...

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Phosphate flow in the chemotactic response system of Helicobacter pylori

Cited by 57 publications

References 45 publications

Cooperation of two distinct coupling proteins creates chemosensory network connections

Cooperation of two distinct coupling proteins creates chemosensory network connections

Chemotaxis inCampylobacter Jejuni

Attractant Binding Induces Distinct Structural Changes to the Polar and Lateral Signaling Clusters in Bacillus subtilis Chemotaxis

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