Article
The giardial ENTH protein participates in lysosomal protein trafficking and endocytosis
Registro en:
FELIZIANI, C. et al. The giardial ENTH protein participates in lysosomal protein trafficking and endocytosis. Biochimica et Biophysica Acta, v. 1853, p. 646–659, 2015.
0006-3002
dx.doi.org/10.1016/j.bbamcr.2014.12.034
Autor
Feliziani, Constanza
Zamponi, Nahuel
Gottig, Natalia
Rópoloa, Andrea S
Rangel, Adriana Lanfredi
Touz, Maria C
Resumen
In the protozoa parasite Giardia lamblia, endocytosis and lysosomal protein trafficking are vital parasite-specific
processes that involve the action of the adaptor complexes AP-1 and AP-2 and clathrin. In this work, we have
identified a single gene in Giardia encoding a protein containing an ENTH domain that defines monomeric
adaptor proteins of the epsin family. This domain is present in the epsin or epsin-related (epsinR) adaptor
proteins, which are implicated in endocytosis and Golgi-to-endosome protein trafficking, respectively, in other
eukaryotic cells. We found that GlENTHp (for G. lamblia ENTH protein) localized in the cytosol, strongly
interacted with PI3,4,5P3,was associatedwith the alpha subunit of AP-2, clathrin and ubiquitin andwas involved
in receptor-mediated endocytosis. It also bonded PI4P, the gamma subunit of AP-1 and was implicated in ER-to-
PV trafficking. Alteration of the GlENTHp function severely affected trophozoite growth showing an unusual
accumulation of dense material in the lysosome-like peripheral vacuoles (PVs), indicating that GlENTHp might
be implicated in themaintenance of PV homeostasis. In this study,we showed evidence suggesting that GlENTHp
might function as a monomeric adaptor protein supporting the findings of other group indicating that GlENTHp
might be placed at the beginning of the ENTH family.