Different secreted phosphatase activities in Leishmania amazonensis

Authors

  • Anne C.S. Fernandes,

    1. Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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  • Deivid C. Soares,

    1. Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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  • Elvira M. Saraiva,

    1. Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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  • José R. Meyer-Fernandes,

    1. Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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  • Thaïs Souto-Padrón

    Corresponding author
    • Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brasil
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Correspondence: Thaïs Souto-Padrón, Instituto de Microbiologia Paulo de Góes, Centro de Ciências da Saúde, Bloco I, Universidade Federal do Rio de Janeiro, Av Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil. Tel.: 55 21 2562 6738; fax: 55 21 2560 8344; e-mail: souto.padron@micro.ufrj.br

Abstract

Leishmania has strong acid phosphatase activity on the external surface of the plasma membrane and secreted into the extracellular milieu. Secreted acid phosphatase (sAcP), which is the most abundant secreted protein of Leishmania, is also a virulence factor that plays a role in vertebrate infection and survival in sand flies. In this study, we characterized the secreted phosphatase activities in Leishmania amazonensis. Both acidic and alkaline secreted phosphatase activities were observed with β-glycerophosphate and p-nitrophenyl phosphate (p-NPP) hydrolysis and were inhibited with sodium tartrate and sodium orthovanadate. Cytochemical labeling revealed a significant difference in the localization of the electron-dense precipitates depending on the substrate. β-Glycerophosphate electron-dense precipitates were concentrated on both the cell surface and flagellar pocket, whereas p-NPP labeling occurred primarily within intracellular organelles. Orthovanadate-treated metacyclic promastigotes were less infective and were confined to a tight parasitophorous vacuole (PV), which is not characteristic of this Leishmania species. Based on the results, we characterized the presence of different secreted phosphatase activities in L. amazonensis, the influence of the substrate in cytochemical labeling, and the potential involvement of secreted phosphatase activity in both PV maturation and amastigote survival.

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