1. Identification of leishmania fructose-1,6-bisphosphate aldolase as a novel activator of host macrophage Src homology 2 domain containing protein tyrosine phosphatase SHP-1
- Author
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Judith M. Silverman, Martin Lopez, Eva Trinh, Thao Dang-Hien Tran, and Devki Nandan
- Subjects
animal structures ,Fructose 1,6-bisphosphate ,Recombinant Fusion Proteins ,Phosphatase ,Biophysics ,Leishmania donovani ,Nitric Oxide Synthase Type II ,Biochemistry ,Chromatography, Affinity ,src Homology Domains ,chemistry.chemical_compound ,Interferon-gamma ,Mice ,Cytosol ,Fructose-Bisphosphate Aldolase ,parasitic diseases ,Animals ,Tyrosine ,Molecular Biology ,Mice, Inbred BALB C ,biology ,Activator (genetics) ,Macrophages ,Protein Tyrosine Phosphatase, Non-Receptor Type 6 ,Aldolase A ,Cell Biology ,biology.organism_classification ,Molecular biology ,In vitro ,Enzyme Activation ,chemistry ,Enzyme Induction ,biology.protein ,Proto-oncogene tyrosine-protein kinase Src ,Protein Binding - Abstract
The macrophage protein tyrosine phosphatase-1 SHP-1 has been implicated in the pathogenesis of infection with leishmania. To identify the factors that may interact with SHP-1, Leishmania donovani promastigote lysates were added to a GST-SHP-1 affinity matrix. A 44 kDa specifically bound protein was identified as leishmania fructose-1,6-bisphosphate aldolase (aldolase). Purified leishmania aldolase bound to SHP-1 indicating that the interaction was direct. In contrast, purified mammalian aldolase did not bind to SHP-1. Consistent with this, leishmania aldolase activated SHP-1 in vitro , whereas mammalian aldolase did not. The presence of leishmania aldolase in the cytosolic fractions prepared from infected macrophages indicated that leishmania aldolase is exported from phagolysosomes in infected cells where it can target host cytosolic proteins. In fact, co-immunoprecipitation showed association of leishmania aldolase with SHP-1. Moreover, leishmania aldolase-expressing macrophages showed the deactivated phenotype of leishmania infected cells as judged by much reduced inability to induce expression of nitric-oxide synthase in response to interferon-γ treatment. Collectively, these data show that leishmania aldolase is a novel SHP-1 binding and activating protein that contributes to macrophage dysfunction.
- Published
- 2007