Trypanosoma rangeli: Differential expression of ecto-phosphatase activities in response to inorganic phosphate starvation

• Published in: Experimental parasitology Vol. 124; no. 4; pp. 386 - 393
• Main Authors: Dick, Claudia Fernanda, dos-Santos, André Luiz Araújo, Fonseca-de-Souza, André L., Rocha-Ferreira, Juliana, Meyer-Fernandes, José Roberto
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01.04.2010; Elsevier
• Subjects: Animals; Biological and medical sciences; Cell culture; Cellular proliferation; Culture Media; Ecto-phosphatase activity; Fundamental and applied biological sciences. Psychology; Humans; Hydrogen-Ion Concentration; Hydrolysis; Inorganic phosphate starvation; Insect Vectors - parasitology; L-Lactate Dehydrogenase - metabolism; Life cycle. Host-agent relationship. Pathogenesis; Nitrophenols - metabolism; Organophosphorus Compounds - metabolism; Phosphates - metabolism; Phosphoric Monoester Hydrolases - metabolism; Protozoa; Rhodnius - parasitology; Rhodnius prolixus; Trypanosoma - enzymology; Trypanosoma rangeli; Trypanosoma rangeli; Cellular proliferation; Inorganic phosphate starvation; Ecto-phosphatase activity; Kinetoplastida; Phosphates; Protozoa; Starvation; Fasting; Parasite; Activity; Proliferation
• ISSN: 0014-4894; 1090-2449
• DOI: 10.1016/j.exppara.2009.12.006

In this work, we showed that living cells of Trypanosoma rangeli express different ecto-phosphatase activities in response to different inorganic phosphate (Pi) concentrations in the culture medium. The ecto-phosphatase activity from T. rangeli grown at low-Pi concentration was inhibited by the increase of the pH, while the ecto-phosphatase of the cells grown at high Pi concentration was not modulated by the change of the pH of the medium. Okadaic acid inhibited only the ecto-phosphatase activity from cells grown at low-Pi concentration but not the ecto-phosphatase activity from cells grown at high-Pi concentration. Accordingly, phosphatase activity from T. rangeli grown at low Pi concentration was able to hydrolyze P-serine and P-threonine at high rate but not P-tyrosine. The phosphatase activity from T. rangeli grown at high-Pi concentration was able to hydrolyze P-serine, P-threonine and P-tyrosine with the same rate. The addition of anterior midgut homogenate of Rhodnius prolixus on the epimastigotes suspension inhibited the enzyme activity of T. rangeli grown at low-Pi concentration. On the other hand, anterior midgut homogenate had no effect in the ecto-phosphatase of T. rangeli maintained at high-Pi concentration. Altogether, the results described here indicate that ecto-phosphatase activities hydrolyzing phosphorylated compounds present in the extracellular medium of T. rangeli are regulated by the external Pi concentration.