Comparative proteomics reveals distinct functions and localization of invasive Entamoeba histolytica and non-invasive Entamoeba moshkovskii proteins

BACKGROUND: Entamoeba histolytica is a pathogenic protozoan accountable for amoebiasis, while Entamoeba moshkovskii is considered non-invasive. Despite morphological similarity, the molecular mechanisms underlying their different pathogenicity remain largely undefined. METHODS: Trophozoite proteins from axenic cultures of E. histolytica and E. moshkovskii were separated and identified using GeLC-MS/MS, and classified using Gene Ontology. Selected and differentially expressed proteins were validated by peptide-specific antibody production, ELISA, and immunofluorescence to determine cellular localization. RESULTS AND DISCUSSION: A total of 1,077 and 1,201 proteins were identified from E. histolytica and E. moshkovskii, respectively. The 801 of Entamoeba common proteins included kinases, GTPase-activating proteins, and heat shock proteins, reflecting conserved cellular processes. E. histolytica-unique proteins involved in nitrogen compound metabolism, vesicle-mediated transport, and catalytic activities, whereas E. moshkovskii proteins were related to lipid metabolism and environmental resilience. Subcellular localization revealed species-specific distribution of MmpL and AIG1-family proteins, suggesting potential roles in pathogenicity and host-immune response. A large proportion of hypothetical proteins was identified, highlighting gaps and opportunities for future study. CONCLUSIONS: Our study highlights conserved and divergent functions and cellular locations of Entamoeba species-specific proteins as insights for distinct pathogenicity and adaptation. MmpL and AIG1 proteins were proposed as potential targets for further diagnostic and therapeutic development.