Vetterlein M, Niapir M, Ellinger A, Neumuller J, Pavelka M.
Brefeldin A regulated retrograde transport into the endoplasmic
reticulum of internalised wheat germ agglutinin.
Histochem Cell Biol. 2003
Aug;120(2):121-8.
Institute of Histology and
Embryology, Department of Cell Biology and Ultrastructure
Research, University of Vienna, Schwarzspanierstrasse 17, 1090
Vienna, Austria.
The effects of the fungal
metabolite Brefeldin A on the endocytic routes of
internalised wheat germ agglutinin (WGA) were studied in human
HepG2 hepatoma cells, drawing particular attention to the
application times in relation to the membrane dynamics occurring
at the trans Golgi face during endocytosis. As shown in previous
studies, transport of internalised WGA into the Golgi apparatus
can be classified in three stages being characterised by
predominance of vesicular endosomes (stage I), formation of an
extended endocytic trans Golgi network (stage II) and uptake of
WGA into the stacked Golgi cisternae (stage III). Brefeldin A
treatment of the cells led to rapid tubular-reticular
transformations of the Golgi stacks. Retrograde transport and
further destinations of internalised WGA depended on the time of
Brefeldin A application. When Brefeldin A was
administered during stages I or II, WGA was localised within the
Brefeldin A -induced tubules and networks, but never was found
within the endoplasmic reticulum. By contrast, Brefeldin A
treatment during stage III led to a redistribution of
internalised WGA into cisternae of the endoplasmic reticulum.
These results show that Brefeldin A administered according
to a precise time schedule can be used as a regulatory agent
that allows to control retrograde traffic of internalised
molecules into the endoplasmic reticulum.
PMID: 12883907 |
