14-3-3 proteins are phosphoserine/phosphothreonine-recognizing adapter proteins that regulate the activity of a vast array of targets. There are also examples of 14-3-3 proteins binding their targets via unphosphorylated motifs. Here we present a structural and biological investigation of the phosphorylation-independent interaction between 14-3-3 and exoenzyme S (ExoS), an ADP-ribosyltransferas...

Pseudomonas aeruginosa exoenzyme S (ExoS) is a type III secretion (TTS) effector, which includes both a GTPase-activating protein (GAP) activity toward the Rho family of low-molecular-weight G (LMWG) proteins and an ADP-ribosyltransferase (ADPRT) activity that targets LMWG proteins in the Ras, Rab, and Rho families. The coordinate function of both activities of ExoS in J774A.1 macrophages was a...

Type III-delivered exoenzyme S (ExoS) preferentially ADP-ribosylated membrane-associated His(6)HRas, relative to its cytosolic derivative His(6)HRas Delta CAAX. This indicates that the subcellular protein distribution contributes to in vivo ADP-ribosylation by ExoS.

Pseudomonas aeruginosa infection of cystic fibrosis patients causes lung damage that is substantially orchestrated by cytokines. In this study, multi-gene probe analysis was used to characterize the ability of the P. aeruginosa mitogen, exoenzyme S, to induce proinflammatory and immunoregulatory cytokines and chemokines. Exoenzyme S strongly induced transcription of proinflammatory cytokines an...

Our previous work has shown that Helicobacter pylori specifically recognizes gangliotetraosylceramide, gangliotriaosylceramide, and phosphatidylethanolamine in vitro. This binding specificity is shared by exoenzyme S from Pseudomonas aeruginosa, and monoclonal antibodies against this adhesin prevent the attachment of H. pylori to its lipid receptors. We now report the use of a novel, versatile ...

ExsA has been implicated as a central regulator of exoenzyme S production by Pseudomonas aeruginosa. In this study, the DNA-binding and transcriptional activation properties of ExsA were investigated. ExsA was produced and purified as a fusion protein, MALA3A2, which was shown to bind specifically to promoter regions that regulated transcription of the exoenzyme S trans-regulatory locus (pC) an...