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Table 3 Key features on Leishmania metacaspases

From: Are protozoan metacaspases potential parasite killers?

  Structure, processing and enzymatic activity Expression, localisation and function References
LdMC1/2 P-rich region in C-terminus No processing with or without oxidative stress (H2O2). R/K specific proteolytic activity at pH 7.5, induced in H2O2 treated parasites. Sensitive to leupeptin, antipain and TLCK but insensitive to caspase inhibitors. Absence of caspase-like protease activity. Expressed in both promastigote and axenic amastigote parasites. Colocalisation with the acidocalcisome compartments. Parasites over-expressing LdMCs are more sensitive to (H2O2)-induced cell death. [36]
LmjMCA P-rich region in C-terminus and signal peptide in N-terminus (functional MLS). Autoprocessing and R-specific proteolytic activity dependent on the H/C catalytic dyad. Absence of caspase-like protease activity. LmjMCA was extensively processed and the central catalytic domain accumulated in the cytosolic subcellular fraction upon cell death induction. Expressed mainly in replicating amastigotes and procyclic promastigotes but less in metacyclic promastigotes. Localised in the nucleus during mitosis and in kinetoplast during organelle segregation. Promastigotes over-expressing LmjMCA suffered from growth retardation and dysregulations in kinetoplast segregation, nuclear division and cytokinesis. Δyca1 yeast over-expressing LmjMCA are more sensitive to (H2O2)-induced cell death. Parasites over-expressing LmjMCA showed mitochondrial over-sensitivity to H2O2. [35, 37, 38]