The Ser/Thr kinase activity of the Yersinia protein kinase A (YpkA) is necessary for full virulence in the mouse, mollifying phagocytes, and disrupting the eukaryotic cytoskeleton

Wiley, David J.; Nordfeldth, Roland; Rosenzweig, Jason A.; DaFonseca, Christopher J.; Gustin, Richard M.; Wolf‐Watz, Hans; Schesser, Kurt

doi:10.1016/j.micpath.2006.02.001

Cited by 51 publications

(51 citation statements)

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“…For quantitative fluorescent microscopy, we used techniques that were originally developed to analyze yeast cells 34,35 . In our standard experiment, we used a Nikon TE2000-U microscope equipped with a Retiga EXi camera (Q Imaging) and MetaMorph software (version 6.3r2, Molecular Devices) to record images from several fields per condition.…”

Section: Methodsmentioning

confidence: 99%

Induction of the Yersinia Type 3 Secretion System as an All-or-None Phenomenon

Wiley

Rosqvist

Schesser

2007

Journal of Molecular Biology

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SummaryPathogenic Yersinia spp. possess a protein secretion system, designated as type 3, that plays a clear role in promoting their survival vis-à-vis the macrophage. Inductive expression of the Yersinia type 3 secretion system (T3SS), triggered either by host cell contact, or, in the absence of host cells, by a reduction in extracellular calcium ion levels, is accompanied by a withdrawal from the bacterial division cycle. Here we analyzed Ca 2+ -dependent induction of the T3SS at the single cell level to understand how Yersinia coordinate their pro-survival and growth-related activities. We utilized a novel high-throughput quantitative microscopy approach as well as flow cytometry to determine how Ca 2+ levels, T3SS expression, and cellular division are interrelated. Our analysis showed that there is a high degree of homogeneity in terms of T3SS expression levels among a population of Y. pseudotuberculosis cells following the removal of Ca 2+ and that T3SS expression appear to be independent of the cellular division cycle. Unexpectedly, our analysis showed that Ca 2+ levels are inversely related to the initiation of inductive T3SS expression, and not to the intensity of activation once initiated, thus providing a basis for the seemingly graded response of T3SS activation observed in bulk-level analyses. The properties of the system described here display both similarities and differences with that of the lac operon first described 50 years ago by Novick and Weiner.

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Section: Methodsmentioning

confidence: 99%

Induction of the Yersinia Type 3 Secretion System as an All-or-None Phenomenon

Wiley

Rosqvist

Schesser

2007

Journal of Molecular Biology

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“…Although they are encoded by a single transcription unit on the 70-kb extrachromosomal virulence plasmid of Yersinia, these two effectors shape the bacterial host relationship in very different ways. YpkA and its associated kinase activity is necessary for the immediate survival of Yersinia following attachment to host cells; this was suggested by animal infection experiments and confirmed at the cellular level in a function-based "infectivity" assay that measures both survival and growth of macrophage-associated Yersinia (3,4). In contrast, there are no discernible differences in the infectivity assay between the wild-type and ⌬yopJ mutant strains (5).…”

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confidence: 88%

“…This is in sharp contrast to studies of T3SS effectors expressed by plant pathogens in which enormous strides have been made due to the fact that these studies are founded on genetic systems dating back to the 1950s (22). In the past several years, it has been shown that a number of T3SS effectors expressed by animal pathogens are active in yeast cells (4,(23)(24)(25)(26); however, to the best of our knowledge, there has only been a single report of using yeast to identify previously unknown host factors important for T3SS effector activity (27). Here, we used the fission yeast Schizosaccharomyces pombe to screen for host factors important for YpkA activity and unexpectedly identified a cellular process in which YpkA and YopJ activities intersect.…”

mentioning

confidence: 94%

“…Here, we used the fission yeast Schizosaccharomyces pombe to screen for host factors important for YpkA activity and unexpectedly identified a cellular process in which YpkA and YopJ activities intersect. Plasmids-The pRep3X GFP, pRep3X GFP-ypkA, pRep3X GFP-ypkA(D270A), pRep41X GFP-ypkA, and pRep41X GFPypkA(D270A) yeast expression plasmids have been described previously (4). Strains possessing an integrated gfp-ypkA were constructed using pJK148 nmt1-GFP-ypkA, pRep6X GFPypkA, and pRep6X GFP-ypkA(D270A) (28).…”

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confidence: 99%

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The Activities of the Yersinia Protein Kinase A (YpkA) and Outer Protein J (YopJ) Virulence Factors Converge on an eIF2α Kinase

Wiley

Shrestha

Yang

et al. 2009

Journal of Biological Chemistry

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The Yersinia protein kinase A (YpkA) and outer protein J (YopJ) are co-expressed from a single transcript and are injected directly into eukaryotic cells by the plague bacterium Yersinia pestis. When overexpressed in vertebrate or yeast cells, YpkA disrupts the actin-based cytoskeletal system by an unknown mechanism, whereas YopJ obstructs inductive chemokine expression by inhibiting MAPK and NF-B signaling. Previously, we showed that the fission yeast Schizosaccharomyces pombe was sensitive to the kinase activity of YpkA. Here, we screened yeast for cellular processes important for YpkA activity and found that the eIF2␣ kinases mollify the toxicity imparted by the kinase activity of YpkA. Specifically, strains lacking the eIF2␣ kinase Hri2 were particularly sensitive to YpkA. Unexpectedly, the activity of YopJ, which conferred a phenotype consistent with its inhibitory effect on MAPK signaling, was also found to be dependent on Hri2. When expressed in S. pombe, YopJ sensitized cells to osmotic and oxidative stresses through a Hri2-dependent mechanism. However, when co-expressed with YpkA, YopJ protected cells from YpkA-mediated toxicity, and this protection was entirely dependent on Hri2. In contrast, YopJ did not confer protection against the toxic effects of the Yersinia virulence factor YopE. These findings are the first to functionally link YpkA and YopJ and suggest that eIF2␣ kinases, which are critically important in antiviral defenses and protection against environmental stresses, also play a role in bacterial virulence.The plague bacterium Yersinia pestis, as well as the closely related enteric pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica, are relatively resistant to the antimicrobial killing systems of innate immune cells. This property is largely dependent on a membrane-bound type 3 secretion system (T3SS) 2 that injects proteins (here referred to as "effectors") directly into the eukaryotic cell (1, 2). This study is focused on two such effectors: YpkA and YopJ (YopO and YopP in Y. enterocolitica). Although they are encoded by a single transcription unit on the 70-kb extrachromosomal virulence plasmid of Yersinia, these two effectors shape the bacterial host relationship in very different ways. YpkA and its associated kinase activity is necessary for the immediate survival of Yersinia following attachment to host cells; this was suggested by animal infection experiments and confirmed at the cellular level in a function-based "infectivity" assay that measures both survival and growth of macrophage-associated Yersinia (3, 4). In contrast, there are no discernible differences in the infectivity assay between the wild-type and ⌬yopJ mutant strains (5). However, YopJ very efficiently blocks MAPK-and NF-B-mediated signaling pathways and the resulting inductive expression of proinflammatory chemokines; the consequences of YopJ activity during an actual infection is a reduction in the local inflammatory response (6 -10). Therefore, unlike YpkA, which is important for the immediate surviv...

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“…Serine/threonine kinases and phosphatases are also involved in bacterial virulence, in particular through their action on host cell substrates. For example, the YpkA/YopO kinase of Yersinia species is delivered into epithelial cells by type III secretion machinery, whereupon it disrupts actin microfilament structure [91].…”

Section: 7a Serine/threonine Phosphorylationmentioning

confidence: 99%

The role of kinases and phosphatases in the pathobiology of porphyromonas gingivalis.

Whitmore¹

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The Ser/Thr kinase activity of the Yersinia protein kinase A (YpkA) is necessary for full virulence in the mouse, mollifying phagocytes, and disrupting the eukaryotic cytoskeleton

Cited by 51 publications

References 29 publications

Induction of the Yersinia Type 3 Secretion System as an All-or-None Phenomenon

Induction of the Yersinia Type 3 Secretion System as an All-or-None Phenomenon

The Activities of the Yersinia Protein Kinase A (YpkA) and Outer Protein J (YopJ) Virulence Factors Converge on an eIF2α Kinase

The role of kinases and phosphatases in the pathobiology of porphyromonas gingivalis.

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