Susceptibility of<i>Escherichia coli</i>to the toxic L-proline analogue L-selenaproline is dependent on two L-cystine transport systems

Deutch, Charles E.; Spahija, I.; Wagner, Christian

doi:10.1111/jam.12623

Cited by 19 publications

(16 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We conclude that the YdjN cation symporter and the FliY/YecSC ABC-type transporter comprise the only two cystine import systems in E. coli. As this paper was being prepared, a similar conclusion was reported by Deutch et al (29), although they reported slow residual cystine import in fliY ydjN mutants. A study in Bacillus subtilis indicated roles for an ABC transporter and a secondary transporter, which show ϳ30% homology to E. coli FliY-YecSC and YdjN, respectively (24).…”

Section: Identification Of the Two Cystine Importers Insupporting

confidence: 83%

Physiological Roles and Adverse Effects of the Two Cystine Importers of Escherichia coli

2015

View full text Add to dashboard Cite

When cystine is added to Escherichia coli, the bacterium becomes remarkably sensitive to hydrogen peroxide. This effect is due to enlarged intracellular pools of cysteine, which can drive Fenton chemistry. Genetic analysis linked the sensitivity to YdjN, a secondary transporter that along with the FliY-YecSC ABC system is responsible for cystine uptake. FliY-YecSC has a nanomolar K m and is essential for import of trace cystine, whereas YdjN has a micromolar K m and is the predominant importer when cystine is more abundant. Oddly, both systems are strongly induced by the CysB response to sulfur scarcity. The FliY-YecSC system can import a variety of biomolecules, including diaminopimelate; it is therefore vulnerable to competitive inhibition, presumably warranting YdjN induction under low-sulfur conditions. But the consequence is that if micromolar cystine then becomes available, the abundant YdjN massively overimports it, at >30 times the total sulfur demand of the cell. The imported cystine is rapidly reduced to cysteine in a glutathione-dependent process. This action avoids the hazard of disulfide stress, but it precludes feedback inhibition of YdjN by cystine. We conjecture that YdjN possesses no cysteine allosteric site because the isostructural amino acid serine might inappropriately bind in its place. Instead, the cell partially resolves the overaccumulation of cysteine by immediately excreting it, completing a futile import/reduction/export cycle that consumes a large amount of cellular energy. These unique, wasteful, and dangerous features of cystine metabolism are reproduced by other bacteria. We propose to rename ydjN as tcyP and fliY-yecSC as tcyJLN. IMPORTANCEIn general, intracellular metabolite pools are kept at steady, nontoxic levels by a sophisticated combination of transcriptional and allosteric controls. Surprisingly, in E. coli allosteric control is utterly absent from the primary importer of cystine. This flaw allows massive overimport of cystine, which causes acute vulnerability to oxidative stress and is remedied only by wasteful cysteine efflux. The lack of import control may be rationalized by the unusual properties of cysteine itself. This phenomenon justifies the existence of countervailing cysteine export systems, whose purpose is otherwise hard to understand. It also highlights an unexpected link between sulfur metabolism and oxidative damage. Although this investigation focused upon E. coli, experiments confirmed that similar phenomena occur in other species.

show abstract

Section: Identification Of the Two Cystine Importers Insupporting

confidence: 83%

Physiological Roles and Adverse Effects of the Two Cystine Importers of Escherichia coli

2015

View full text Add to dashboard Cite

show abstract

“…Since the protein is not predicted to have any periplasmic domains, we find it unlikely that MdfA is a Tat substrate (44,48). fliY is the first gene in a putative operon (fliY yecS yecC) encoding proteins with a suggested function in cysteine transport that were previously identified in E. coli (49). These genes do not appear to be essential in E. coli, but this could be different in Yersinia.…”

Section: Discussionmentioning

confidence: 84%

The Tat Substrate SufI Is Critical for the Ability of Yersinia pseudotuberculosis To Cause Systemic Infection

et al. 2017

View full text Add to dashboard Cite

The twin arginine translocation (Tat) system targets folded proteins across the inner membrane and is crucial for virulence in many important humanpathogenic bacteria. Tat has been shown to be required for the virulence of Yersinia pseudotuberculosis, and we recently showed that the system is critical for different virulence-related stress responses as well as for iron uptake. In this study, we wanted to address the role of the Tat substrates in in vivo virulence. Therefore, 22 genes encoding potential Tat substrates were mutated, and each mutant was evaluated in a competitive oral infection of mice. Interestingly, a ΔsufI mutant was essentially as attenuated for virulence as the Tat-deficient strain. We also verified that SufI was Tat dependent for membrane/periplasmic localization in Y. pseudotuberculosis. In vivo bioluminescent imaging of orally infected mice revealed that both the ΔsufI and ΔtatC mutants were able to colonize the cecum and Peyer's patches (PPs) and could spread to the mesenteric lymph nodes (MLNs). Importantly, at this point, neither the ΔtatC mutant nor the ΔsufI mutant was able to spread systemically, and they were gradually cleared. Immunostaining of MLNs revealed that both the ΔtatC and ΔsufI mutants were unable to spread from the initial infection foci and appeared to be contained by neutrophils, while wild-type bacteria readily spread to establish multiple foci from day 3 postinfection. Our results show that SufI alone is required for the establishment of systemic infection and is the major cause of the attenuation of the ΔtatC mutant.KEYWORDS Yersinia pseudotuberculosis, Tat pathway, virulence, SufI, mesenteric lymph nodes, neutrophils T he genus Yersinia includes three species that are pathogenic to humans: Yersinia pestis, the causative agent of plague, and the two enteropathogens Y. enterocolitica and Y. pseudotuberculosis, which normally cause a self-limiting disease with symptoms ranging from mild diarrhea, enterocolitis, septicemia, and mesenteric lymphadenitis to reactive arthritis in humans after ingestion of contaminated food or water (1). Once it is ingested, Y. pseudotuberculosis traverses the epithelial barrier through M cells and infects the associated lymphoid tissues, such as Peyer's patches (PPs) and cecal patches, and later spreads to the mesenteric lymph nodes (MLNs). Although the infection is usually self-limited in humans, the infection caused by the two enteropathogenic Yersinia species in mice readily progresses to become systemic and disseminates to the spleen and liver (2). The main virulence arsenal of Yersinia is the type III secretion system (T3SS), which is encoded by an ϳ70-kb virulence plasmid. The T3SS enables the translocation of virulence effector proteins directly into the cytosol of the target host cell, which results in the disruption of host signaling and early immune

show abstract

“…CyuP is different from the two previously described cysteine/cystine transporters in E. coli. The E. coli TcyJ-TcyL-TcyN system transports both cystine and diaminopimelate, is sensitive to osmotic shock (24)(25)(26)(27), and probably corresponds to the osmotic shock-sensitive CTS-1 in S. enterica (28). The E. coli TcyP transporter is specific for cystine and is resistant to osmotic shock (24,25).…”

mentioning

confidence: 99%

“…The E. coli TcyJ-TcyL-TcyN system transports both cystine and diaminopimelate, is sensitive to osmotic shock (24)(25)(26)(27), and probably corresponds to the osmotic shock-sensitive CTS-1 in S. enterica (28). The E. coli TcyP transporter is specific for cystine and is resistant to osmotic shock (24,25). Regulation is a major distinguishing feature of these systems; cysteine limitation and CysB control TcyJLN and TcyP (24,26,28,29), whereas exogenous cysteine and CyuR regulate CyuP.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Anaerobic Cysteine Degradation and Potential Metabolic Coordination in Salmonella enterica and Escherichia coli

et al. 2017

View full text Add to dashboard Cite

Salmonella enterica has two CyuR-activated enzymes that degrade cysteine, i.e., the aerobic CdsH and an unidentified anaerobic enzyme; Escherichia coli has only the latter. To identify the anaerobic enzyme, transcript profiling was performed for E. coli without cyuR and with overexpressed cyuR. Thirty-seven genes showed at least 5-fold changes in expression, and the cyuPA (formerly yhaOM) operon showed the greatest difference. Homology suggested that CyuP and CyuA represent a cysteine transporter and an iron-sulfur-containing cysteine desulfidase, respectively. E. coli and S. enterica ΔcyuA mutants grown with cysteine generated substantially less sulfide and had lower growth yields. Oxygen affected the CyuRdependent genes reciprocally; cyuP-lacZ expression was greater anaerobically, whereas cdsH-lacZ expression was greater aerobically. In E. coli and S. enterica, anaerobic cyuP expression required cyuR and cysteine and was induced by L-cysteine, D-cysteine, and a few sulfur-containing compounds. Loss of either CyuA or RidA, both of which contribute to cysteine degradation to pyruvate, increased cyuP-lacZ expression, which suggests that CyuA modulates intracellular cysteine concentrations. Phylogenetic analysis showed that CyuA homologs are present in obligate and facultative anaerobes, confirming an anaerobic function, and in archaeal methanogens and bacterial acetogens, suggesting an ancient origin. Our results show that CyuA is the major anaerobic cysteine-catabolizing enzyme in both E. coli and S. enterica, and it is proposed that anaerobic cysteine catabolism can contribute to coordination of sulfur assimilation and amino acid synthesis.IMPORTANCE Sulfur-containing compounds such as cysteine and sulfide are essential and reactive metabolites. Exogenous sulfur-containing compounds can alter the thiol landscape and intracellular redox reactions and are known to affect several cellular processes, including swarming motility, antibiotic sensitivity, and biofilm formation. Cysteine inhibits several enzymes of amino acid synthesis; therefore, increasing cysteine concentrations could increase the levels of the inhibited enzymes. This inhibition implies that control of intracellular cysteine levels, which is the immediate product of sulfide assimilation, can affect several pathways and coordinate metabolism. For these and other reasons, cysteine and sulfide concentrations must be controlled, and this work shows that cysteine catabolism contributes to this control.

show abstract

Susceptibility ofEscherichia colito the toxic L-proline analogue L-selenaproline is dependent on two L-cystine transport systems

Abstract: Because susceptibility to selenium-containing analogues of L-proline and L-cystine is dependent on multiple transport systems, these compounds may be effective in the treatment of urinary tract infections.

Cited by 19 publications

References 69 publications

Physiological Roles and Adverse Effects of the Two Cystine Importers of Escherichia coli

Physiological Roles and Adverse Effects of the Two Cystine Importers of Escherichia coli

The Tat Substrate SufI Is Critical for the Ability of Yersinia pseudotuberculosis To Cause Systemic Infection

Anaerobic Cysteine Degradation and Potential Metabolic Coordination in Salmonella enterica and Escherichia coli

Contact Info

Product

Resources

About