The eukaryotic host factor that activates exoenzyme S of Pseudomonas aeruginosa is a member of the 14-3-3 protein family.

Fu, Haian; Coburn, Jenifer; Collier, R. J.

doi:10.1073/pnas.90.6.2320

Cited by 253 publications

(181 citation statements)

References 38 publications

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“…Host factor activation of YpkA may be a strategy by which Yersinia prevents YpkA from being active within the bacterial cell. This strategy is utilized by pathogens such as Bordetella pertussis and Pseudomonas aeruginosa which express a calmodulin-activated adenylate cyclase (Cya) and a 14-3-3-activated Ras modifying toxin (ExoS), respectively (42)(43)(44). In these latter examples it is thought that the host cell activator is simply an abundant cytosolic protein that serves as an "on" switch for the toxin.…”

Section: Fig 6 Yeast Two-hybrid Assaysmentioning

confidence: 99%

The Yersinia Protein Kinase A Is a Host Factor Inducible RhoA/Rac-binding Virulence Factor

Dukuzumuremyi

Rosqvist

Hållberg

et al. 2000

Journal of Biological Chemistry

103

112

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The pathogenic yersiniae inject proteins directly into eukaryotic cells that interfere with a number of cellular processes including phagocytosis and inflammatory-associated host responses. One of these injected proteins, the Yersinia protein kinase A (YpkA), has previously been shown to affect the morphology of cultured eukaryotic cells as well as to localize to the plasma membrane following its injection into HeLa cells. Here it is shown that these activities are mediated by separable domains of YpkA. The amino terminus, which contains the kinase domain, is sufficient to localize YpkA to the plasma membrane while the carboxyl terminus of YpkA is required for YpkAs morphological effects. YpkAs carboxyl-terminal region was found to affect the levels of actin-containing stress fibers as well as block the activation of the GTPase RhoA in Yersinia-infected cells. We show that the carboxyl-terminal region of YpkA, which contains sequences that bear similarity to the RhoAbinding domains of several eukaryotic RhoA-binding kinases, directly interacts with RhoA as well as Rac (but not Cdc42) and displays a slight but measurable binding preference for the GDP-bound form of RhoA. Surprisingly, YpkA binding to RhoA GDP affected neither the intrinsic nor guanine nucleotide exchange factor-mediated GDP/GTP exchange reaction suggesting that YpkA controls activated RhoA levels by a mechanism other than by simply blocking guanine nucleotide exchange factor activity. We go on to show that YpkAs kinase activity is neither dependent on nor promoted by its interaction with RhoA and Rac but is, however, entirely dependent on heat-sensitive eukaryotic factors present in HeLa cell extracts and fetal calf serum. Collectively, our data show that YpkA possesses both similarities and differences with the eukaryotic RhoA/Rac-binding kinases and suggest that the yersiniae utilize the Rho GTPases for unique activities during their interaction with eukaryotic cells.

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Section: Fig 6 Yeast Two-hybrid Assaysmentioning

confidence: 99%

The Yersinia Protein Kinase A Is a Host Factor Inducible RhoA/Rac-binding Virulence Factor

Dukuzumuremyi

Rosqvist

Hållberg

et al. 2000

Journal of Biological Chemistry

103

112

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“…The GTPase-activating protein activity of ExoS has been linked to cytoskeletal alterations , while the ADPRT activity of ExoS is required for the effects of bacterially translocated ExoS on human epithelial cell DNA synthesis, re-adherence and long-term cytoskeletal alterations (Fraylick et al, 2001). When internalized by bacterial TTS, ExoS ADPRT activity targets multiple cellular LMMG proteins (McGuffie et al, 1998;Fraylick et al, 2002a, b) and requires a eukaryotic cofactor, 14-3-3, for catalytic activity (Coburn et al, 1991;Fu et al, 1993;Masters et al, 1999;Henriksson et al, 2000b). ADP-ribosylation of cellular targets, Ras and RalA, has been found to interfere with their respective signal transduction pathways Ganesan et al, 1999;Henriksson et al, 2000a;Fraylick et al, 2002b), thereby linking a cellular mechanism to the effects of ExoS on eukaryotic cell function.…”

Section: Introductionmentioning

confidence: 99%

Cell line differences in bacterially translocated ExoS ADP-ribosyltransferase substrate specificity

et al. 2003

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Exoenzyme S (ExoS) is an ADP-ribosyltransferase (ADPRT) directly translocated into eukaryotic cells by the type III secretory (TTS) process of Pseudomonas aeruginosa. Comparisons of the functional effects of ExoS on human epithelial and murine fibroblastic cells showed that human epithelial cells exhibited an overall increased sensitivity to the effects of bacterially translocated ExoS on cell proliferation, morphology and re-adherence. ExoS was also found to ADP-ribosylate a greater number of low-molecular-mass G (LMMG) proteins in human epithelial cells, as compared to murine fibroblasts. Examination of the cellular mechanism for differences in ExoS ADPRT substrate modification found that the more restricted pattern of substrate modification in murine fibroblasts was not linked to the efficiency of bacterial adherence nor to the efficiency of ExoS internalization by the TTS process. In exploring the cellular nature of patterns of substrate modification, more extensive substrate modification was detected in human and simian cell lines, while rodent cell lines, including rat, mouse and hamster lines, consistently exhibited the more limited pattern of LMMG protein ADP-ribosylation. Patterns of substrate modification were not altered by cellular transformation and occurred independently of cell type. These studies suggest that eukaryotic cell properties, as recognized through studies of cells of different animal origins, affect the substrate targeting of ExoS ADPRT activity, and that this in turn can influence the severity of effects of ExoS on host-cell function.

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“…Another role for 14-3-3 is suggested by the intrinsic adenosine diphosphate (ADP)-ribosylation cofactor activity of these proteins identified by Fu and co-workers (16 be envisioned. Because 14-3-3 proteins can form dimers in vitro (18), they may form bridges that connect proto-oncogene and oncogene products with other signaling or cytoskeletal proteins.…”

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confidence: 99%

14-3-3: Modulators of Signaling Proteins?

Morrison

1994

Science

199

112

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Horvaith and Rabai also provide a dramatic dye-based visual demonstration that the miscibility of fluorous and nonfluorous phases can depend on temperature. Hence, reactions could be conducted under homogeneous conditions at elevated temperatures and then cooled to effect product separation. Other engineering advantages that could be associated with FBS chemistry are easily imagined. For example, a reaction involving a fluorinated catalyst might be conducted in a single organic phase, and a fluorous phase loop in the product stream could be used for catalyst recovery. Alternatively, in an environmental application, toxic wastes could be extracted from product streams by immobilized fluorous binding agents. It should also be kept in mind that interfacial reactions may be dominant in some FBS chemistry. As the field develops, there will be a particular need for data on this point and the effect of solvent and ponytail structure on phase properties, solubilities, and related phenomena.The above FBS hydroformylation can also be analyzed in the context of other rhodium-catalyzed reactions involving phosphines designed to confer special phase properties. First, sulfonated aryl phosphines have been shown to similarly immobilize rhodium catalysts in the aqueous phases of organic-aqueous biphase systems. Commercial hydroformylation plants making use of this technology have been in operation since 1984 (5). However, rates are constrained by the limited solubilities of the reactants in the aqueous phase. Second, rhodium has also been ligated to phosphines containing poly(alkene)oxide chains, fCHRCH20), (6 However, the strategy in this game is even easier than that in "pin the tail on the donkey," as any point of attachment can in principle produce a winner. Given the large number of industrial and academic research laboratories that will likely want to step up and play, it will be surprising if practical and widely adopted applications do not result.

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The eukaryotic host factor that activates exoenzyme S of Pseudomonas aeruginosa is a member of the 14-3-3 protein family.

Abstract: Exoenzyme S (ExoS), which has been implicated as a virulence factor of Pseudomonas aeruginosa, catalyzes transfer of the ADP-ribose moiety of NADI to many eukaryotic cellular proteins. Its preferred substrates include Ras and several other 21-to 25-kDa GTP-binding proteins.

Cited by 253 publications

References 38 publications

The Yersinia Protein Kinase A Is a Host Factor Inducible RhoA/Rac-binding Virulence Factor

The Yersinia Protein Kinase A Is a Host Factor Inducible RhoA/Rac-binding Virulence Factor

Cell line differences in bacterially translocated ExoS ADP-ribosyltransferase substrate specificity

14-3-3: Modulators of Signaling Proteins?

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