Functional conservation of the Giardia lamblia epsin-like protein in Saccharomyces cerevisiae

FELIZIANI C; ROPOLO AS; WENDLAND B; TOUZ MC

Mar del Plata

Congreso; SAP; 2014

Endocytosis and lysosomal protein trafficking is essential in pathogenic parasites since it is directly linked to vital parasite-specific processes. The epsin N-terminal homology (ENTH) domain is an evolutionarily conserved protein module found primarily in proteins that participate in clathrin-mediated trafficking. By searching in the GDB, we found the protein GlENTHp (for G. lamblia ENTH protein) contains an ENTH domain, which is present in the epsin or epsinR form and is involved in endocytosis and protein trafficking from the Golgi to the lysosomes, respectively. Our findings suggest a dual epsin-epsinR role of GlENTHp, since it was able to bind clathrin, ubiquitin and also interacts with αAP-2 and γAP-1, with the events of endocytosis and lysosomal hydrolase trafficking being equally affected by GlENTHp downregulation.There are two homologues of epsin, Ent1p and Ent2p, and two orthologous of epsinR, Ent3p and Ent5p in S. cerevisiae. ENT1 and ENT2 are two redundant genes and deletion of both genes (ent1Δent2Δ) is lethal. On the other hand, strains lacking both Ent3p and Ent5p (ent3Δent5Δ), but not single mutant strains, exhibit defects in TGN/endosome traffic and protein sorting into the vacuole lumen.Because many components of the endocytic machinery are structurally and functionally conserved between eukaryotes, the main objective of this work was to analyze whether GlENTHp might play a function working as epsin or epsinR (or both) in S. cerevisiae.