Cysteine protease that cleaves specifically after arginine or lysine residues (PubMed:22402587). In epimastigotes, may play a role in cell cycle G1/S transition (PubMed:22402587). Activated by Ca(2+). Localizes to cytoplasm in epimastigotes (PubMed:16213036). Translocates to the nucleus following apoptosis induced by human serum (PubMed:16213036). Expressed in epimastigotes, amastigotes and cell derived trypomastigotes and in metacyclic trypomastigotes (at protein level). In epimastigotes, the unprocessed enzyme appears to be the main form (PubMed:22402587). Auto-processing is dispensable for catalytic activity towards small oligopeptide substrates (PubMed:22402587). Belongs to the peptidase C14B family.