Interactions among the seven<i>Helicobacter pylori</i>proteins encoded by the urease gene cluster

Voland, Petra; Weeks, David L.; Marcus, Elizabeth A.; Prinz, Christian; Sachs, George; Scott, David

doi:10.1152/ajpgi.00160.2002

Cited by 98 publications

(107 citation statements)

References 37 publications

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“…These comprised the following interactions: UreA with UreB, UreA with UreH, UreE with UreG, and UreF with UreH; the two latter interactions were confirmed by Y2H and co-immunoprecipitation (47). Phenotypes of insertion mutations in the corresponding urease genes in H. pylori were in agreement with their implication in urease activation (47,48). In addition, our data are consistent with biochemical data obtained for urease of Klebsiella aerogenes.…”

Section: Table I Tap-tagged Proteinssupporting

confidence: 90%

“…This complex is in agreement with our previous Y2H analysis that defined pairwise protein-protein interactions with some of the H. pylori urease proteins (16). These comprised the following interactions: UreA with UreB, UreA with UreH, UreE with UreG, and UreF with UreH; the two latter interactions were confirmed by Y2H and co-immunoprecipitation (47). Phenotypes of insertion mutations in the corresponding urease genes in H. pylori were in agreement with their implication in urease activation (47,48).…”

Section: Table I Tap-tagged Proteinsmentioning

confidence: 52%

“…It can be envisioned that the small proportion of activated urease is sequestered in a compartment of the cell to improve its activity in connection for instance with the ammonium-incorporating enzyme, glutamine synthetase, under conditions of normal growth or with the urea inner membrane channel, UreI, for efficient substrate delivery upon acid stress. Accordingly a UreI-dependent membrane association of urease was reported previously (47,61).…”

Section: Table I Tap-tagged Proteinsmentioning

confidence: 69%

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In Vivo Interactome of Helicobacter pylori Urease Revealed by Tandem Affinity Purification

Stingl

Schauer

Ecobichon

et al. 2008

Molecular & Cellular Proteomics

102

114

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In the human gastric bacterium Helicobacter pylori, two metalloenzymes, hydrogenase and urease, are essential for in vivo colonization, the latter being a major virulence factor. The UreA and UreB structural subunits of urease and UreG, one of the accessory proteins for Ni 2؉ incorporation into apourease, were taken as baits for tandem affinity purification. The method allows the purification of protein complexes under native conditions and physiological expression levels of the bait protein. Protein-protein interactions are operative at the majority of cellular processes; thus, their study gives valuable insight into proteomic and functional associations. Helicobacter pylori is a Gram-negative bacterium that is infecting the stomach of about half of the human population. It is responsible for the development of gastric pathologies such as gastritis, gastroduodenal ulcer, and adenocarcinoma (1). One remarkable feature of H. pylori is its capacity to persist (often during decades) and multiply in the hostile environment of the stomach. In H. pylori, urease is a major virulence factor and is essential for the resistance to acidity because of its capacity to hydrolyze urea into bicarbonate and ammonia (2), which results in pH homeostasis of the bacterium. The protein is an extremely active and highly regulated member of the nickel metalloenzyme family. Activation of urease, i.e. incorporation of nickel into the active site, requires urease-specific accessory proteins whose homologues have been extensively studied genetically and biochemically in Klebsiella pneumoniae (3)(4)(5)(6)(7)(8). It is still enigmatic why vast amounts of urease, up to 10% of the total protein, are produced, whereas only a minor active portion is sufficient for acid resistance (9). Furthermore the observation that urease is even indispensable for the colonization under neutral conditions (10) suggested additional essential functions for this central enzyme that remained unidentified.H. pylori possesses another nickel-containing enzyme, a [NiFe] hydrogenase, allowing this organism to utilize hydrogen as an energy source. Accordingly hydrogenase has been shown to be essential for H. pylori colonization in the mouse model (11). The assembly of the [NiFe] hydrogenase metal center located in the large hydrogenase subunit is partially understood and requires several proteins involved in the sequential delivery of iron before nickel (for a review, see Ref. 12). In addition, the [NiFe] hydrogenase possesses a small subunit containing [Fe-S] clusters. For the assembly of the latter no distinct biosynthetic pathway has been attributed so far, suggesting that the housekeeping [Fe-S] cluster assembly system might be involved (12). H. pylori is unique in that the maturation events of these two nickel-containing essential proteins are interconnected as H. pylori mutants deficient in one of the accessory proteins, HypA or HypB, involved in nickel insertion into hydrogenase, lack significant activation of urease (13).

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Section: Table I Tap-tagged Proteinssupporting

confidence: 90%

Section: Table I Tap-tagged Proteinsmentioning

confidence: 52%

Section: Table I Tap-tagged Proteinsmentioning

confidence: 69%

See 1 more Smart Citation

In Vivo Interactome of Helicobacter pylori Urease Revealed by Tandem Affinity Purification

Stingl

Schauer

Ecobichon

et al. 2008

Molecular & Cellular Proteomics

102

114

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“…Indeed, coexpression of the ureI, ureE, ureF, ureG and ureH genes was shown to be required along with structural genes ureA and ureB to yield fully active urease in E. coli (Cussac et al 1992). More recently, Voland and coworkers have shown that H. pylori ureE, ureF, ureG and ureH mutants are severely deficient in urease activity (Voland et al 2003). Among these four genes, the roles of ureE and ureG have drawn the most attention.…”

Section: Accessory Proteins For Urease Maturationmentioning

confidence: 99%

“…In addition to these nickel enzymes, H. pylori also possesses a NixA nickel specific permease (Bauerfeind et al 1996), accessory proteins UreIEFGH and HypABCDEF (some of which bind nickel) required for maturation or activation of the apoenzymes for the two nickel enzymes (Benoit et al 2004;Mehta et al 2003a;Olson et al 2001;Voland et al 2003), a nickel dependent regulator, NikR (Contreras et al 2003;van Vliet et al 2002), a recently identified nickel efflux system (CznABC) (Stahler et al 2006) and a histidine-rich heat shock protein, HspA, a GroES homologue Kansau and Labigne 1996). Here we address the roles and characteristics of these proteins, with emphasis on the roles of the accessory proteins directly required for Ni-enzyme maturation, and on the His-rich putative nickel storage proteins Hpn and Hpn-like.…”

mentioning

confidence: 99%

Nickel-binding and accessory proteins facilitating Ni-enzyme maturation in Helicobacter pylori

2007

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Helicobacter pylori colonizes the human gastric mucosa and this can lead to chronic gastritis, peptic and duodenal ulcers, and even gastric cancers. The bacterium colonizes over one-half of the worlds population. Nickel plays a major role in the bacteriums colonization and persistence attributes as two nickel enzyme sinks obligately contain the metal. Urease accounts for up to 10% of the total cellular protein made and is required for initial colonization processes, and the hydrogen oxidizing hydrogenase provides the bacterium a high-energy substrate yielding low potential electrons for energy generation. A battery of accessory proteins are needed for maturation or activation of each of the apoen-zymes. These include Ni-chaperones and GTPas-es, some of which are unique to each Ni-enzyme and others that are individually required for maturation of both the Ni-enzymes. H. pylori's need for some conventional hydrogenase maturation proteins playing roles in urease maturation may have to do with the poor nickel-sequestering ability of the UreE urease maturation protein compared to other systems. H. pylori also possesses a NixA nickel specific permease, a nickel dependent regulator (NikR), a recently identified nickel efflux system (CznABC), and a histidinerich heat shock protein, HspA. Based on mutant analysis approaches all these proteins have roles in nickel homeostasis, in urease expression, and in host colonization. The His-rich putative nickel storage proteins Hpn and Hpn-like play roles in nickel detoxification and may influence the levels of Ni-activated urease that can be achieved.

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Chaperones of Nickel Metabolism

Quiroz

Kim

Mulrooney

et al. 2007

Nickel and Its Surprising Impact in Nature

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Interactions among the sevenHelicobacter pyloriproteins encoded by the urease gene cluster

Cited by 98 publications

References 37 publications

In Vivo Interactome of Helicobacter pylori Urease Revealed by Tandem Affinity Purification

In Vivo Interactome of Helicobacter pylori Urease Revealed by Tandem Affinity Purification

Nickel-binding and accessory proteins facilitating Ni-enzyme maturation in Helicobacter pylori

Chaperones of Nickel Metabolism

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