Acid phosphatase activity of promastigotes of Leishmania donovani: a marker of virulence

Singla, Neena; Khuller, G. K.; Vinayak, V. K.

doi:10.1016/0378-1097(92)90634-z

Cited by 20 publications

(29 citation statements)

References 26 publications

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“…In other parasites, acid phosphatase has been proposed as a virulence factor [59], [60], [61], [62]. However, the AcPh from Giardia does not seem to be secreted, even in contact with intestinal cells [63].…”

Section: Discussionmentioning

confidence: 99%

Vacuolar Protein Sorting Receptor in Giardia lamblia

et al. 2012

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In Giardia, lysosome-like peripheral vacuoles (PVs) need to specifically coordinate their endosomal and lysosomal functions to be able to successfully perform endocytosis, protein degradation and protein delivery, but how cargo, ligands and molecular components generate specific routes to the PVs remains poorly understood. Recently, we found that delivering membrane Cathepsin C and the soluble acid phosphatase (AcPh) to the PVs is adaptin (AP1)-dependent. However, the receptor that links AcPh and AP1 was never described. We have studied protein-binding to AcPh by using H6-tagged AcPh, and found that a membrane protein interacted with AcPh. This protein, named GlVps (for Giardia lamblia Vacuolar protein sorting), mainly localized to the ER-nuclear envelope and in some PVs, probably functioning as the sorting receptor for AcPh. The tyrosine-binding motif found in the C-terminal cytoplasmic tail domain of GlVps was essential for its exit from the endoplasmic reticulum and transport to the vacuoles, with this motif being necessary for the interaction with the medium subunit of AP1. Thus, the mechanism by which soluble proteins, such as AcPh, reach the peripheral vacuoles in Giardia appears to be very similar to the mechanism of lysosomal protein-sorting in more evolved eukaryotic cells.

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Section: Discussionmentioning

confidence: 99%

Vacuolar Protein Sorting Receptor in Giardia lamblia

et al. 2012

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“…For example, Coxiella burnetti and Entamoeba histolytica secrete molecules with AcP activity and this activity possesses PTPase activity (Baca et al 1993;AnayaRuiz et al 2003). In L. donovani, it has been shown that an acid phosphatase cloned from promastigotes correlated with the degree of virulence (Singla et al 1992). …”

Section: Discussionmentioning

confidence: 99%

Leishmania mexicana promastigotes secrete a protein tyrosine phosphatase

et al. 2010

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Leishmania mexicana is an intracellular protozoan parasite that infects macrophages and dendritic cells and causes a chronic cutaneous disease. Although many enzymatic activities have been reported in this parasite, the presence of kinases and phosphatases has been poorly studied. These enzymes control the phosphorylation and dephosphorylation of proteins. Specifically, protein tyrosine kinases phosphorylate tyrosine residues and protein tyrosine phosphatases (PTPases) dephosphorylate tyrosine residues. PTPase activities have been reported as pathogenic factors in various infectious microorganisms such as viruses, bacteria, and parasites. Also, it has been shown that the induction of one or more PTPase activities in macrophages represents an important pathogenicity factor in Leishmania. Recently, we reported a membrane-bound PTPase activity in promastigotes of Leishmania major. In the present work, we give evidence that promastigotes of L. mexicana are able to secrete a PTPase into the culture medium. Two antibodies: one monoclonal against the catalytic domains of the human placental PTPase 1B and a polyclonal rabbit anti-recombinant protein Petase7 from Trypanosoma brucei cross-reacted with a 50-kDa molecule. The anti-human PTPase 1B antibody depleted the enzymatic activity present in the conditioned medium. The pattern of sensitivity and resistance to specific PTPase and serine/threonine inhibitors showed that this enzyme is a protein tyrosine phosphatase.

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“…Proteases, acid phosphatases, superoxide dismutases, heat-shock proteins and other 'stress' proteins are often important virulence factors in parasitic protozoa of vertebrates and invertebrates (Katakura 1986, Katakura & Kobayashi 1988, Hervio et al 1991, Singala et al 1992, Vannier-Santos et al 1995, Wiese 1998, Volety & Chu 1997. Many of these proteins have been used to characterize virulence in relation to disease.…”

Section: Biochemistry Of Infectionmentioning

confidence: 99%

A review of the parasitic dinoflagellates Hematodinium species and Hematodinium-like infections in marine crustaceans

Stentiford

Shields²

2005

Dis. Aquat. Org.

202

285

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Parasitic dinoflagellates in the genus Hematodinium are important parasites of marine Crustacea. Outbreaks of these parasites have damaged commercial stocks of Norway lobster Nephrops norvegicus, snow crab Chionoecetes opilio, Tanner crab C. bairdi, American blue crab Callinectes sapidus, and velvet swimming crab Necora puber. Species of Hematodinium can reach high enough levels to regulate their host populations, but mortalities are also centred on the unfished juveniles and females, hosts not normally sampled by fisheries; hence impacts are often underreported. Seasonal prevalences of up to 85% occur annually in many host populations; in effect, these parasites form cryptic blooms in the water column with crabs and other crustaceans at risk of disease. We review the biology and ecology of Hematodinium spp. infections in crustaceans. Included is a comparison of the different infections, a synthesis of what is known, and an attempt to highlight fruitful areas for continued research. DISEASES OF AQUATIC ORGANISMS

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Acid phosphatase activity of promastigotes of Leishmania donovani: a marker of virulence

Cited by 20 publications

References 26 publications

Vacuolar Protein Sorting Receptor in Giardia lamblia

Vacuolar Protein Sorting Receptor in Giardia lamblia

Leishmania mexicana promastigotes secrete a protein tyrosine phosphatase

A review of the parasitic dinoflagellates Hematodinium species and Hematodinium-like infections in marine crustaceans

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