Cysteine-protease activity elicited by Ca2+ stimulus in Plasmodium

Cysteine-protease activity elicited by Ca2+ stimulus in Plasmodium

Author Farias, S. L. Google Scholar
Gazarini, M. L. Google Scholar
Melo, R. L. Google Scholar
Hirata, I. Y. Google Scholar
Juliano, M. A. Google Scholar
Juliano, L. Google Scholar
Garcia, CRS Google Scholar
Institution Universidade de São Paulo (USP)
Universidade Federal de São Paulo (UNIFESP)
Abstract Bloodstage malaria parasites require proteolytic activity for key processes as invasion, hemoglobin degradation and merozoite escape from red blood cells (RBCs). We investigated by confocal microscopy the presence of cysteine-protease activity elicited by calcium stimulus in Plasmodium chabaudi and Plasmodium falciparum in free trophozoites or for the later parasite within RBC using fluorescence resonance energy transfer (FRET) peptides. Peptide probes access, to either free or intraerythrocytic parasites, was also tested by selecting a range of fluorescent peptides (653-3146 Da molecular mass) labeled with Abz or FITC. in the present work we show that Ca2+ stimulus elicited by treatment with either melatonin, thapsigargin, ionomicin or nigericin, promotes an increase of substrate hydrolysis, which was blocked by the specific cysteine-protease inhibitor E-64 and the intracellular Ca2+ chelator, BAPTA. When parasites were treated with cytoplasmic Ca2+ releasing compounds, a cysteine-protease was labeled in the parasite cytoplasm by the fluorescent specific irreversible inhibitor, Ethyl-Eps-Leu-Tyr-Cap-Lys(Abz)-NH2, where Ethyl-Eps is Ethyl-(2S,3S)-oxirane-2,3-dicarboxylate. in summary, we demonstrate that P. chabaudi and P. falciparum have a cytoplasmic dependent cysteine-protease activity elicited by Ca2+. (c) 2005 Elsevier B.V. All rights reserved.
Keywords malaria
Language English
Date 2005-05-01
Published in Molecular and Biochemical Parasitology. Amsterdam: Elsevier B.V., v. 141, n. 1, p. 71-79, 2005.
ISSN 0166-6851 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 71-79
Access rights Closed access
Type Article
Web of Science ID WOS:000228680600007

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