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.
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 44kDa 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-gamma treatment. Collectively, these data show that leishmania aldolase is a novel SHP-1 binding and activating protein that contributes to macrophage dysfunction.
Nandan
Devki
D
Department of Medicine, Division of Infectious Diseases, 2733 Heather Street, Heather Pavilion East, Room 452-D, Vancouver, BC, Canada V5Z 3J5.
Tran
Thao
T
Trinh
Eva
E
Silverman
Judith M
JM
Lopez
Martin
M
D000818:Animals; D002846:Chromatography, Affinity; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D004790:Enzyme Induction / Q000187:drug effects; D005634:Fructose-Bisphosphate Aldolase / Q000302:isolation & purification / Q000378:metabolism*; D007371:Interferon-gamma / Q000494:pharmacology; D007893:Leishmania donovani / Q000187:drug effects / Q000201:enzymology*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000201:enzymology* / Q000469:parasitology*; D051379:Mice; D008807:Mice, Inbred BALB C; D052247:Nitric Oxide Synthase Type II / Q000096:biosynthesis; D011485:Protein Binding / Q000187:drug effects; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000737:chemistry* / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D018909:src Homology Domains
D011993:Recombinant Fusion Proteins; D007371:Interferon-gamma; D052247:Nitric Oxide Synthase Type II; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6; D005634:Fructose-Bisphosphate Aldolase