Actin activates Pseudomonas aeruginosa ExoY nucleotidyl cyclase toxin and ExoY-like effector domains from MARTX toxins

Belyy, Alexander; Raoux-Barbot, Dorothée; Saveanu, Cosmin; Namane, Abdelkader; Ogryzko, Vasily; Worpenberg, Lina; David, Violaine; Henriot, Véronique; Fellous, Souad; Merrifield, Christien J.; Assayag, Elodie; Ladant, Daniel; Renault, Louis; Mechold, Undine

doi:10.1038/ncomms13582

Cited by 54 publications

(128 citation statements)

References 61 publications

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“…As predicted, the reduced motility led the reduction in bacterial adherence to cells (Fig. ExoY has been proposed to require a mammalian cytosolic protein, perhaps Factin, for the stimulation of its activity within cytoplasm of infected hosts [17]. PAK wt and DST mutant also exhibited reduced motility only under T3SS-inducing condition generated by addition of EGTA to the medium (Fig.…”

Section: Discussionsupporting

confidence: 54%

“…The impairment could be caused by ExoYmediated Tau hyperphosphorylation, which reduces assembly of microtubule, key targets of adenylate cyclase, resulting in increasing vascular permeability by forming interendothelial gaps [13,14], although these effects of ExoY were claimed as not observed in some studies [15,16]. In contrast, ExoY results in rather increasing microfilament content in cells by competing with activated Arp2/3 complex for binding to F-actin, which was found to be a mammalian cofactor for the proper action of ExoY catalytic activity [17]. In addition, ExoY was involved in increasing the spread of endothelial cells, which is possibly through the stabilization of actin cytoskeleton [16].…”

Section: Introductionmentioning

confidence: 99%

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T3SS effector ExoY reduces inflammasome‐related responses by suppressing bacterial motility and delaying activation of NF‐κB and caspase‐1

et al. 2017

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Type III-secreted effectors are essential for modulating host immune responses during the pathogenesis of Pseudomonas aeruginosa infections. Little is known about the impact of one of the effectors, ExoY, on inflammasome activation, which results in IL-1β production and pyroptotic cell death. In this study, we found that transcriptional expression of Il-1β was induced to a lesser extent in response to an exoY-harboring strain than to a deleted mutant. This suppressive effect of ExoY was verified by complementation assay as well as by direct translocation of exoY into host cells. In addition to the production of IL-1β, pyroptotic cell death was also diminished in response to an exoY-harboring strain. These inflammasome responses were mediated by the adenylate cyclase activity of ExoY, which plays a role in delaying the activation of NF-κB and caspase-1, a key component of inflammasome-mediated responses. Moreover, the negative effects of ExoY on these responses were in part conferred by the suppression of bacterial motility, which could reduce the degree of bacterial contact with cells. Together, these results demonstrate that the adenylate cyclase activity of P. aeruginosa ExoY can reduce inflammasome-related responses by influencing both the host and the bacterium itself by delaying the activation of inflammatory pathways and suppressing bacterial motility.

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Section: Discussionsupporting

confidence: 54%

Section: Introductionmentioning

confidence: 99%

T3SS effector ExoY reduces inflammasome‐related responses by suppressing bacterial motility and delaying activation of NF‐κB and caspase‐1

et al. 2017

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“…Work on stringent cyclic mononucleotide synthases shows that quite limited variations give rise to different specificities; cyclic GMP synthases can be experimentally changed to cyclic AMP synthases, and vice versa, by just two or three amino acid exchanges (95,96). On the other hand, relaxed enzymes can produce several different cyclic nucleotides (97). In addition, a three-amino-acid replacement in the human cyclic dinucleotide synthase cyclic GMP-AMP synthase (cGAS) changes the phosphodiester linkage specificity so that 3=3= cyclic GMP-AMP rather than the noncanonical 2=3= cyclic GMP-AMP is synthesized (98).…”

Section: Discussionmentioning

confidence: 99%

Progress in Understanding the Molecular Basis Underlying Functional Diversification of Cyclic Dinucleotide Turnover Proteins

2017

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Cyclic di-GMP was the first cyclic dinucleotide second messenger described, presaging the discovery of additional cyclic dinucleotide messengers in bacteria and eukaryotes. The GGDEF diguanylate cyclase (DGC) and EAL and HD-GYP phosphodiesterase (PDE) domains conduct the turnover of cyclic di-GMP. These three unrelated domains belong to superfamilies that exhibit significant variations in function, and they include both enzymatically active and inactive members, with a subset involved in synthesis and degradation of other cyclic dinucleotides. Here, we summarize current knowledge of sequence and structural variations that underpin the functional diversification of cyclic di-GMP turnover proteins. Moreover, we highlight that superfamily diversification is not restricted to cyclic di-GMP signaling domains, as particular DHH/DHHA1 domain and HD domain proteins have been shown to act as cyclic di-AMP phosphodiesterases. We conclude with a consideration of the current limitations that such diversity of action places on bioinformatic prediction of the roles of GGDEF, EAL, and HD-GYP domain proteins.KEYWORDS cyclic dinucleotide second messenger, GGDEF domain, EAL domain, HD-GYP domain, DHH/DHHA1 domain, cyclic GAMP, cyclic di-AMP, cyclic di-GMP, second messenger T he dinucleotide cyclic di-GMP is the most abundant second messenger in bacteria. It promotes the environmental lifestyle switch between sessility and motility, as well as the host-related lifestyle switch between acute and chronic/benign infection. A hallmark of the cyclic di-GMP signaling network is an apparent redundancy of cyclic di-GMP turnover proteins encoded in one genome. However, many of these proteins have distinct N-terminal sensing and signaling domains, suggesting that their activities in cyclic di-GMP turnover respond posttranslationally to various (and different) intraand extracellular signals. In gross terms, the number of cyclic di-GMP turnover proteins is linearly correlated with genome size within the different bacterial phyla, with Thermotogae having one of the highest cyclic di-GMP-related "IQs," the density of enzymes per megabase pair, with some species harboring over 100 cyclic di-GMP turnover proteins (http://www.ncbi.nlm.nih.gov/Complete_Genomes/c-di-GMP.html). As in other domain superfamilies, extensive sequence diversity exists. Here, we review the knowledge on the translation of sequence diversity of cyclic di-GMP turnover proteins into functional diversity. We conclude by discussing whether and how a unified nomenclature for cyclic di-GMP turnover proteins can be established.

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“…Heated extracts were inactive, suggesting that the cofactor for ExoY was likely a protein. The identity of the eukaryotic cofactor(s) for ExoY remains elusive, although just recently, filamentous actin (F-actin) has been reported to be sufficient to confer ExoY activity (Belyy et al 2016). To study the biological activity of ExoY, an effector-less strain of P. aeruginosa was constructed (PA103Δ exoUexoT ::Tc) and rExoY was coordinately expressed with the T3SS machinery for injection into CHO cells (Yahr et al 1998).…”

Section: Studies On the Discovery Of Exoy And Its Enzymatic Activitymentioning

confidence: 99%

“…ExoY + and ExoY K81M infections both led to apparent F-actin disruption in epithelial cells within 2-hours, suggesting the ExoY protein but not its enzymatic activity interferes with F-actin alignment. Just recently, the Mechold group (Belyy et al 2016) revealed an interaction between ExoY and F-actin. F-actin was found to bind directly to ExoY where it served as a putative enzymatic cofactor.…”

Section: Exoy and Disruption Of The Endothelial Cytoskeletonmentioning

confidence: 99%

The Pseudomonas aeruginosa Exoenzyme Y: A Promiscuous Nucleotidyl Cyclase Edema Factor and Virulence Determinant

Morrow

Frank

Balczon

et al. 2016

Non-Canonical Cyclic Nucleotides

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Exoenzyme Y (ExoY) was identified as a component of the Pseudomonas aeruginosa type 3 secretion system secretome in 1998. It is a common contributor to the arsenal of type 3 secretion system effectors, as it is present in approximately 90% of Pseudomonas isolates. ExoY has adenylyl cyclase activity that is dependent upon its association with a host cell cofactor. However, recent evidence indicates that ExoY is not just an adenylyl cyclase; rather, it is a promiscuous cyclase capable of generating purine and pyrimidine cyclic nucleotide monophosphates. ExoY’s enzymatic activity causes a characteristic rounding of mammalian cells, due to microtubule breakdown. In endothelium, this cell rounding disrupts cell-to-cell junctions, leading to loss of barrier integrity and an increase in tissue edema. Microtubule breakdown seems to depend upon tau phosphorylation, where the elevation of cyclic nucleotide monophosphates activates protein kinases A and G and causes phosphorylation of endothelial microtubule associated protein tau. Phosphorylation is a stimulus for tau release from microtubules, leading to microtubule instability. Phosphorylated tau accumulates inside endothelium as a high molecular weight, oligomeric form, and is then released from the cell. Extracellular high molecular weight tau causes a transmissible cytotoxicity that significantly hinders cellular repair following infection. Thus, ExoY may contribute to bacterial virulence in at least two ways; first, by microtubule breakdown leading to loss of endothelial cell barrier integrity, and second, by promoting release of a high molecular weight tau cytotoxin that impairs cellular recovery following infection.

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Actin activates Pseudomonas aeruginosa ExoY nucleotidyl cyclase toxin and ExoY-like effector domains from MARTX toxins

Cited by 54 publications

References 61 publications

T3SS effector ExoY reduces inflammasome‐related responses by suppressing bacterial motility and delaying activation of NF‐κB and caspase‐1

T3SS effector ExoY reduces inflammasome‐related responses by suppressing bacterial motility and delaying activation of NF‐κB and caspase‐1

Progress in Understanding the Molecular Basis Underlying Functional Diversification of Cyclic Dinucleotide Turnover Proteins

The Pseudomonas aeruginosa Exoenzyme Y: A Promiscuous Nucleotidyl Cyclase Edema Factor and Virulence Determinant

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