The giardial epsin-like protein possess a dual epsin-epsinR role in clathrin-mediated trafficking. -Feliziani C., Zamponi N., Gottig, N., Rópolo A.S.

CONSTANZA FELIZIANI; NAHUEL ZAMPONI; NATALIA GOTTIG; ROPOLO ANDREA; ADRIANA LANFREDI-RANGEL; MARIA CAROLINA TOUZ

Congreso; Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2014

The epsin N-terminal homology (ENTH) domain is an evolutionarily conserved protein module that defines monomeric adaptor proteins of the epsin family. It is present in the epsin or epsin-related (epsinR) proteins, which are implicated in the endocytosis and Golgi-to-endosomes protein trafficking, respectively, in other eukaryotic cells. In Giardia we found a single gene encoding a protein containing an ENTH domain (GlENTHp for G. lamblia ENTH protein), which localized in the cytosol and, like epsin, was associated with áAP-2, clathrin, ubiquitin, interacted with PI3,4,5P3, and was involved in receptor-mediated endocytosis. This protein also bonded ãAP-1, PI4P, and was implicated in ER-to-PV trafficking, like epsinR proteins. Alteration of the GlENTHp function affected trophozoite growth showing an accumulation of dense material in the lysosome-like peripheral vacuoles (PVs), indicating that GlENTHp might be implicated in the maintenance of the PV homeostasis. When the ENTH protein family was analyzed in an evolutionary context, it was suggested that the subfamily of epsin proteins was acquired more recently probably by duplication of the epsinR. In this study, we showed evidence that places GlENTHp at the beginning of the whole family, summarizing the function of epsin and epsinR and suggesting that GlENTHp might be the epsinR adaptor from which all the family evolves