Regulation by Ca2+ in the Yersinia low‐Ca2+ response

Straley, Susan C.; Plano, Gregory V.; Skrzypek, Elźbieta; Haddix, Pryce L.; Fields, Kenneth A.

doi:10.1111/j.1365-2958.1993.tb01644.x

Cited by 201 publications

(212 citation statements)

References 33 publications

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“…Indeed as with Rv2027c, the cytoplasmic fragments of these kinases utilized Ca 2þ as the divalent cation in autophosphorylation reactions [4,21]. Apart from their role in in vitro autophosphorylation, Mg 2þ and Ca 2þ ions have also been implicated as signals sensed by two-component systems regulating virulence in Yersinia [22] and Salmonella [23]. For instance, by examining the Mg 2þ levels in its surroundings via PhoQ protein, Salmonella determines its subcellular location; whereas a low (micromolar) Mg 2þ concentration signals an intracellular environment (i.e., phagosome) a high (0.7-1 mM) Mg 2þ concentration denotes an extracellular environment, thereby promoting entry of genes required for survival within or entry into host cells [23].…”

Section: Discussionmentioning

confidence: 99%

Cross talk between DevS sensor kinase homologue, Rv2027c, and DevR response regulator of Mycobacterium tuberculosis

SAINI¹

2004

FEBS Letters

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Rv2027c is a putative orphan histidine sensor kinase that bears strong homology to DevS of the hypoxia-responsive DevR-DevS two-component system in M. tuberculosis. The cytosolic C-terminal domain of Rv2027c protein (Rv2027c 194 ) was overexpressed in E. coli and biochemically characterized. Rv2027c 194 underwent autophosphorylation at a conserved His 392 residue and engaged in phosphotransfer with DevR response regulator. The rates of autophosphorylation and the stabilities of the phosphorylated species were broadly similar in Rv2027c and DevS. However, unlike DevS, Rv2027c utilized Ca 2þ as an alternative divalent ion during autophosphorylation. In contrast to DevS which completed phosphotransfer to DevR in 5-10 min, phosphotransfer from Rv2027c$P was only partial at 30 min. Unlike devS transcription that was hypoxia-responsive, Rv2027c transcript levels were not upregulated from basal levels during hypoxia. The differential regulation of devS and Rv2027c genes, the ability of Rv2027c to utilize Ca 2þ as a divalent cation in autophosphorylation at physiological concentrations and to engage in phosphotransfer with DevR suggests that the DevR regulon could be modulated by more than one environmental cue relayed through DevS and Rv2027c.

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Section: Discussionmentioning

confidence: 99%

Cross talk between DevS sensor kinase homologue, Rv2027c, and DevR response regulator of Mycobacterium tuberculosis

SAINI¹

2004

FEBS Letters

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“…Interestingly, both Yersinia spp. and P. aeruginosa TTSSs are responsive to low calcium levels in vitro (Frank, 1997;Straley et al, 1993;Sundin et al, 2002) and target cell contact in vivo (Pettersson et al, 1996;Rosqvist et al, 1994;Vallis et al, 1999). Therefore, it is significant that even with common inductive responses and high amino acid relatedness, P. aeruginosa-derived PopD alone or in combination with PcrH was unable to complement the regulatory defects of DyopD or DlcrH yopD null mutants of Yersinia.…”

Section: Discussionmentioning

confidence: 99%

Dissection of homologous translocon operons reveals a distinct role for YopD in type III secretion by Yersinia pseudotuberculosis

et al. 2003

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The homologous pcrGVHpopBD and lcrGVHyopBD translocase operons of Pseudomonas aeruginosa and pathogenic Yersinia spp., respectively, are responsible for the translocation of anti-host effectors into the cytosol of infected eukaryotic cells. In Yersinia, this operon is also required for yop-regulatory control. To probe for key molecular interactions during the infection process, the functional interchangeability of popB/yopB and popD/yopD was investigated. Secretion of PopB produced in trans in a DyopB null mutant of Yersinia was only observed when co-produced with its native chaperone PcrH, but this was sufficient to complement the yopB translocation defect. The Yersinia DyopD null mutant synthesized and secreted PopD even in the absence of native PcrH, yet this did not restore YopD-dependent yop-regulatory control or effector translocation. Thus, this suggests that key residues in YopD, which are not conserved in PopD, are essential for functional Yersinia type III secretion. INTRODUCTIONAll pathogenic Yersinia spp. encode a wide assortment of virulence determinants to establish a host infection (Revell & Miller, 2001). Significantly, a common plasmid-borne type III secretion system (TTSS) is essential for the fitness of Yersinia inside the host . This specialized virulence strategy links protein secretion across the bacterial envelope with translocation of anti-host virulence effectors through the plasma membrane of target eukaryotic cells. Effector proteins localized inside the target cell disable crucial signal transduction pathways, rendering the cell incapable of mounting an effective immune defence (Bliska, 2000; Fällman et al., 2002).The bacterial envelope component of the TTSSs of many plant-and animal-interacting bacteria resembles the flagella basal body, while a hollow needle-like protrusion extends from the bacterial surface through which effectors are believed to traverse (Blocker et al., 1999;Hoiczyk & Blobel, 2001;Jin & He, 2001;Kubori et al., 1998; Sekiya et al., 2001;Tamano et al., 2000). Furthermore, translocation into target cells by Yersinia requires the structural proteins LcrV, YopB and YopD. These proteins interact (Neyt & Cornelis, 1999b;Sarker et al., 1998) to presumably form a complex that facilitates pore formation in target cell membranes to allow entry of effector proteins into target cells (Bröms et al., 2003a; Holmström et al., 2001;Neyt & Cornelis, 1999a;Tardy et al., 1999). At odds with this dogma is a report suggesting that the needle component YscF is the sole requirement for effector translocation (Hoiczyk & Blobel, 2001). Clearly, the molecular mechanisms of this process are still unresolved. Interestingly, both LcrV and YopD also contribute to the control of type III substrate synthesis and secretion. Yop synthesis in LcrV-defective strains is significantly down-regulated (Bergman et al., 1991;Price et al., 1991;Skrzypek & Straley, 1995). On the other hand, Yersinia defective for YopD constitutively produce Yop proteins and LcrV (Francis & Wolf-Watz, 1998;Williams & Strale...

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“…The ysc-encoded type III secretion system in Yersinia mediates the secretion of a large number of virulence factors denoted Yops ( Yersinia outer proteins) (for a review, see Cornelis, 1992;Forsberg et al, 1994;Straley et al, 1993). For Yersinia, secretion of the Yops by the type III secretion system has been shown to be coupled to a cell contact-dependent translocation of specific Yops across the eukaryotic cell membrane into the cytosol of the host cell .…”

Section: Introductionmentioning

confidence: 99%

Intracellular targeting of exoenzyme S of Pseudomonas aeruginosa via type III‐dependent translocation induces phagocytosis resistance, cytotoxicity and disruption of actin microfilaments

Frithz‐Lindsten

Rosqvist

et al. 1997

Molecular Microbiology

198

262

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SummaryExoenzyme S (ExoS) is an ADP-ribosyltransferase secreted by the opportunistic pathogen Pseudomonas aeruginosa. The amino-terminal half of ExoS exhibits homology to the YopE cytotoxin of pathogenic Yersinia. Recently, YopE was found to be translocated into the host cell by a bacteria-cell contact-dependent mechanism involving the ysc-encoded type III secretion system. By using an approach in which exoS was expressed in different strains of Yersinia, including secretion and translocation mutants, we could demonstrate that ExoS was secreted and translocated into HeLa cells by a similar mechanism to that described previously for YopE. Similarly to YopE, the presence of ExoS in the host cell elicited a cytotoxic response, correlating with disruption of the actin microfilament structure. A similar cytotoxic response was also induced by a mutated form of ExoS with a more than 2000-fold reduced ADP-ribosyltransferase activity. However, the enzymatically active ExoS elicited a more definite rounding up of the HeLa cells, which also correlated with decreased viability of the cells after prolonged infection compared with cells infected with strains expressing mutated ExoS or YopE. This suggests that ExoS can act through two different mechanisms on the host cell. The expression of ExoS by Yersinia also mediated an anti-phagocytic effect on macrophages. In addition, we present evidence that extracellularly located P. aeruginosa is able to target ExoS into eukaryotic cells. Taken together, our data suggest that P. aeruginosa, by analogy with Yersinia, targets virulence proteins into the eukaryotic cytosol via a type III secretion-dependent mechanism as part of an anti-phagocytic strategy.

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Regulation by Ca²⁺ in the Yersinia low‐Ca²⁺ response

Cited by 201 publications

References 33 publications

Cross talk between DevS sensor kinase homologue, Rv2027c, and DevR response regulator of Mycobacterium tuberculosis

Cross talk between DevS sensor kinase homologue, Rv2027c, and DevR response regulator of Mycobacterium tuberculosis

Dissection of homologous translocon operons reveals a distinct role for YopD in type III secretion by Yersinia pseudotuberculosis

Intracellular targeting of exoenzyme S of Pseudomonas aeruginosa via type III‐dependent translocation induces phagocytosis resistance, cytotoxicity and disruption of actin microfilaments

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