Localization of the Yersinia PTPase to focal complexes is an important virulence mechanism

The protein tyrosine phosphatase YopH, produced by the pathogen Yersinia ps eudotuberculosis, is an essential virulence determinant involved in antipha gocytosis. Upon infection, YopH Is translocated into the target cell, where it recognizes focal complexes. Genetic analysis revealed that YopH harbour s 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 withi n target cells. The region is also essential for antiphagocytosis and virul ence, illustrating the biological significance of localization of YopH to f ocal complexes during Yersinia infection. These results also indicate that focal complexes play a role In the general phagocytic process.