Trypanosoma rangeli: a possible role for ecto-phosphatase activity on cell proliferation.
Here we demonstrate for the first time that growth of Trypanosoma rangeli, a protozoa parasite, is strongly dependent on the presence of inorganic phosphate (Pi) in the culture medium and that the replacement of the inorganic phosphate in the culture medium by beta-glycerophosphate, a substrate for phosphatases lead the cells to achieve its maximal growth. The ecto-phosphatase activity present on the external surface of T. rangeli decreased during the growth phase of the parasite, suggesting that this enzyme could be important for the development. Accordingly, the inhibition of this ecto-phosphatase activity by sodium orthovanadate also inhibited the proliferation of T. rangeli. Parasites maintained in a Pi-starved culture medium (2 mM Pi) had 4-fold more ecto-phosphatase activity as compared to parasites maintained in a Pi-supplemented culture medium (50 mM Pi). Altogether, these results presented here suggest that this ecto-phosphatase activity leads to hydrolysis of phosphorylated compounds present in the extracellular medium, which could contribute to the acquisition of inorganic phosphate during the development of T. rangeli epimastigotes.
Fonseca-de-Souza
André L
AL
Laboratório de Bioquímica Celular, Instituto de Bioquímica Medica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, CCS, bloco H, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ, Brazil.
Dick
Claudia Fernanda
CF
dos Santos
André Luiz Araújo
AL
Fonseca
Fábio Vasconcelos
FV
Meyer-Fernandes
José Roberto
JR
D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D003470:Culture Media; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D014345:Trypanosoma / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*
D003470:Culture Media; D010710:Phosphates; D010749:Phosphoprotein Phosphatases