CIQUIBIC   05472
CENTRO DE INVESTIGACIONES EN QUIMICA BIOLOGICA DE CORDOBA
Unidad Ejecutora - UE
artículos
Título:
Cytoplasmic tails of SialT2 and GalNAcT impose their respective proximal and distal Golgi localization.
Autor/es:
ULIANA A., GIRAUDO, C.G. AND MACCIONI, H.J.F.
Revista:
Traffic
Editorial:
Blackwell Munksgaard
Referencias:
Lugar: Oxford, UK; Año: 2006 vol. 7 p. 604 - 612
ISSN:
1398-9219
Resumen:
Complex glycolipid synthesis is catalyzed by different
glycosyltransferases resident of the Golgi complex.
Most of them are type II membrane proteins comprising
a lumenal, C-terminal domain linked to an N-terminal
domain (Ntd) constituted by a short cytoplasmic tail
(ct), a transmembrane, and a lumenal stem regions.
They concentrate selectively in different sub-Golgi compartments,
in an overlapped manner, acting in succession
in the addition of sugars to acceptor glycolipids. The
Ntds are sufficient to localize glycosyltransferases in the
Golgi complex, but it is not clear whether they also confer
selective concentration in sub-Golgi compartments.
Here, we studied whether the Ntd of SialT2, localized in
the proximal Golgi, and the one of GalNAcT, a trans/TGN
Golgi-concentrated enzyme, concentrate reporter proteins
in the corresponding sub-Golgi compartment. The
sub-Golgi concentration of the Ntds fused to spectral
variants of the GFP was determined in CHO-K1 cells
from their behavior upon addition of brefeldin A.
Fluorescence microscopy and subcellular fractionation
showed that the SialT2 Ntd concentrates in a proximal
sub-Golgi compartment and that of GalNAcT in TGN
elements. Exchanging the transmembrane region and
the cts of SialT2 and GalNAcT indicates that information
for proximal or distal Golgi concentration is associated
with the cts.trans/TGN
Golgi-concentrated enzyme, concentrate reporter proteins
in the corresponding sub-Golgi compartment. The
sub-Golgi concentration of the Ntds fused to spectral
variants of the GFP was determined in CHO-K1 cells
from their behavior upon addition of brefeldin A.
Fluorescence microscopy and subcellular fractionation
showed that the SialT2 Ntd concentrates in a proximal
sub-Golgi compartment and that of GalNAcT in TGN
elements. Exchanging the transmembrane region and
the cts of SialT2 and GalNAcT indicates that information
for proximal or distal Golgi concentration is associated
with the cts.