期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1991
卷号：88
期号：4
页码：1187-1191
DOI：10.1073/pnas.88.4.1187
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The plasmid-encoded YopH protein is a protein-tyrosine phosphatase (PTPase; EC 3.1.3.48 ) that is essential for Yersinia virulence. We have investigated the molecular basis for the role of PTPase activity in Yersinia pathogenesis. Allelic recombination was employed to introduce a defined mutation into the yopH plasmid gene. Conversion of the essential Cys-403 to Ala in the catalytic domain of the protein abolished YopH PTPase activity and significantly reduced the virulence of Yersinia pseudotuberculosis in a murine infection model. 32P-labeled phosphotyrosine-containing proteins were immunoprecipitated from extracts of Y. pseudotuberculosis-infected cell monolayers and analyzed by SDS/PAGE to assess the impact of YopH on host protein phosphorylation. Major proteins of 200, 120, and 60 kDa were dephosphorylated in macrophages associated with wild-type Y. pseudotuberculosis. Selective removal of phosphate from the 120- and 60-kDa proteins was shown to be specific to the YopH PTPase activity. Phagocytosis of the bacteria was not required for this dephosphorylation activity, suggesting that YopH is functionally expressed by extracellular bacteria. These observations indicate that the essential function of YopH in Yersinia pathogenesis is host-protein dephosphorylation.
