| 1. |
- Holmström, Anna, et al.
(författare)
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LcrV is a channel size-determining component of the Yop effector translocon of Yersinia
- 2001
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Ingår i: Molecular Microbiology. - : Blackwell Publishing. - 0950-382X .- 1365-2958. ; 39:3, s. 620-632
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Tidskriftsartikel (refereegranskat)abstract
- Delivery of Yop effector proteins by pathogenic Yersinia across the eukaryotic cell membrane requires LcrV, YopB and YopD. These proteins were also required for channel formation in infected erythrocytes and, using different osmolytes, the contact‐dependent haemolysis assay was used to study channel size. Channels associated with LcrV were around 3 nm, whereas the homologous PcrV protein of Pseudomonas aeruginosa induced channels of around 2 nm in diameter. In lipid bilayer membranes, purified LcrV and PcrV induced a stepwise conductance increase of 3 nS and 1 nS, respectively, in 1 M KCl. The regions important for channel size were localized to amino acids 127–195 of LcrV and to amino acids 106–173 of PcrV. The size of the channel correlated with the ability to translocate Yop effectors into host cells. We suggest that LcrV is a size‐determining structural component of the Yop translocon.
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| 2. |
- Persson, Cathrine, et al.
(författare)
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Localization of the Yersinia PTPase to focal complexes is an important virulence mechanism
- 1999
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Ingår i: Molecular Microbiology. - : Wiley-Blackwell Publishing Inc.. - 0950-382X .- 1365-2958. ; 33:4, s. 828-838
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Tidskriftsartikel (refereegranskat)abstract
- The protein tyrosine phosphatase YopH, produced by the pathogen Yersinia pseudotuberculosis, is an essential virulence determinant involved in antiphagocytosis. Upon infection, YopH is translocated into the target cell, where it recognizes focal complexes. Genetic analysis revealed that YopH harbours a region that is responsible for specific localization of this PTPase to focal complexes in HeLa cells and professional phagocytes. This region is a prerequisite for blocking an immediate-early Yersinia-induced signal within target cells. The region is also essential for antiphagocytosis and virulence, illustrating the biological significance of localization of YopH to focal complexes during Yersinia infection. These results also indicate that focal complexes play a role in the general phagocytic process.
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| 3. |
- Persson, Cathrine, et al.
(författare)
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Cell-surface-bound Yersinia translocate the protein tyrosine phosphatase YopH by a polarized mechanism into the target cell
- 1995
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Ingår i: Molecular Microbiology. - : John Wiley & Sons. - 0950-382X .- 1365-2958. ; 18:1, s. 135-150
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Tidskriftsartikel (refereegranskat)abstract
- YopH is translocated by cell-surface-bound bacteria through the plasma membrane to the cytosol of the HeLa cell. The transfer mechanism is contact dependent and polarizes the translocation to only occur at the contact zone between the bacterium and the target cell. More than 99% of the PTPase activity is associated with the HeLa cells. In contrast to the wild-type strain, the yopBD mutant cannot deliver YopH to the cytosol. Instead YopH is deposited in localized areas in the proximity of cell-associated bacteria. A yopN mutant secretes 40% of the total amount of YopH to the culture medium, suggesting a critical role of YopN in regulation of the polarized translocation. Evidence for a region in YopH important for its translocation through the plasma membrane of the target cell but not for secretion from the pathogen is provided.
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