The gene repertoire of the main cysteine protease of Trypanosoma cruzi, cruzipain, reveals four sub-types with distinct active sites

• Published in: Scientific reports Vol. 11; no. 1; p. 18231
• Main Authors: Santos, Viviane Corrêa, Oliveira, Antonio Edson Rocha, Campos, Augusto César Broilo, Reis-Cunha, João Luís, Bartholomeu, Daniella Castanheira, Teixeira, Santuza Maria Ribeiro, Lima, Ana Paula C. A., Ferreira, Rafaela Salgado
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14-09-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/114; 631/45/468; Catalytic Domain; Chagas disease; Chromosomes; Cruzipain; Cysteine; Cysteine Endopeptidases - chemistry; Cysteine Endopeptidases - genetics; Cysteine Endopeptidases - metabolism; Cysteine proteinase; Enzymes; Epimastigotes; Gene Expression Regulation, Developmental; Genes; Humanities and Social Sciences; Life Cycle Stages - genetics; Life cycles; multidisciplinary; Papain; Parasites; Phylogeny; Protozoa; Protozoan Proteins - chemistry; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Science; Science (multidisciplinary); Trypanosoma cruzi; Trypanosoma cruzi - enzymology; Trypanosoma cruzi - genetics; Trypanosoma cruzi - growth & development; Trypomastigotes; Vector-borne diseases
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-97490-2

Cruzipains are the main papain-like cysteine proteases of
Trypanosoma cruzi
, the protozoan parasite that causes Chagas disease. Encoded by a multigenic family, previous studies have estimated the presence of dozens of copies spread over multiple chromosomes in different parasite strains. Here, we describe the complete gene repertoire of cruzipain in three parasite strains, their genomic organization, and expression pattern throughout the parasite life cycle. Furthermore, we have analyzed primary sequence variations among distinct family members as well as structural differences between the main groups of cruzipains. Based on phylogenetic inferences and residue positions crucial for enzyme function and specificity, we propose the classification of cruzipains into two families (I and II), whose genes are distributed in two or three separate clusters in the parasite genome, according with the strain. Family I comprises nearly identical copies to the previously characterized cruzipain 1/cruzain, whereas Family II encompasses three structurally distinct sub-types, named cruzipain 2, cruzipain 3, and cruzipain 4. RNA-seq data derived from the CL Brener strain indicates that Family I genes are mainly expressed by epimastigotes, whereas trypomastigotes mainly express Family II genes. Significant differences in the active sites among the enzyme sub-types were also identified, which may play a role in their substrate selectivity and impact their inhibition by small molecules.