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SpvC is a Salmonella effector with phosphothreonine lyase activity on host mitogen‐activated protein kinases
Author(s) -
Mazurkiewicz Piotr,
Thomas Jerry,
Thompson Jessica A.,
Liu Mei,
Arbibe Laurence,
Sansonetti Philippe,
Holden David W.
Publication year - 2008
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.2008.06134.x
Subject(s) - biology , effector , cytosol , mapk/erk pathway , microbiology and biotechnology , protein kinase a , kinase , salmonella , secretion , plasmid , virulence , biochemistry , bacteria , enzyme , gene , genetics
Summary SpvC is encoded by the Salmonella virulence plasmid. We have investigated the biochemical function of SpvC and the mechanism by which it is secreted by bacteria and translocated into infected macrophages. We constructed a strain carrying a deletion in spvC and showed that the strain is attenuated for systemic virulence in mice. SpvC can be secreted in vitro by either the SPI‐1 or SPI‐2 type III secretion systems. Cell biological and genetic experiments showed that translocation of the protein into the cytosol of macrophages by intracellular bacteria is dependent on the SPI‐2 T3SS. Using antibodies specific to phospho‐amino acids and mass spectrometry we demonstrate that SpvC has phosphothreonine lyase activity on full‐length phospho‐Erk (pErk) and a synthetic 13‐amino‐acid phospho‐peptide containing the TXY motif. A Salmonella strain expressing spvC from a plasmid downregulated cytokine release from infected cells.