INVESTIGADORES
ROPOLO Andrea Silvana
congresos y reuniones científicas
Título:
Vacuolar protein sorting receptor: new molecular evidence of a sorting pathway in Giardia lamblia
Autor/es:
MIRAS S; FELIZIANI C; ZAMPONI N; QUIROGA R; ROPOLO A; TOUZ MC
Lugar:
Mendoza
Reunión:
Congreso; XLVIII Reunión Annual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular.; 2012
Resumen:
In Giardia,
lysosome-like peripheral vacuoles (PVs) need to specifically coordinate their
endosomal and lysosomal functions to be able to successfully perform
endocytosis, protein degradation and protein delivery, but how cargo, ligands
and molecular components generate specific routes to the PVs remains poorly
understood. Recently, we found that delivering membrane Cathepsin C and the
soluble acid phosphatase (AcPh) to the PVs is adaptin (AP-1) dependent. However,
the receptor that links AcPh and AP1 was never described. We have studied
protein-binding to AcPh by using H6-tagged AcPh, and found that a membrane protein
interacted with AcPh. This protein, named GlVps mainly localized to the
ER-nuclear envelope and in some PVs, probably functions as the sorting receptor
for AcPh. The tyrosin-binding mitif found in the C-terminal cytoplasmic tail
domain of GlVps was essential for its exit from the endoplasmic reticulum and
transport to the vacuoles, with this motif being necessary for the interaction
with the medium subunit of AP1. Thus, the mechanism by which soluble proteins,
such as AcPh, reach the peripheral vacuoles in Giardia appears to be very
similar to the mechanism of lysosomal protein-sorting in more evolved eukaryotic
cells.