Open AccessGeneration of Alzheimer β-amyloid protein in the trans-Golgi network in the apparent absence of vesicle formation
Author(s) -
Huaxi Xu,
David Sweeney,
Rong Wang,
Shuai Wang,
Amy Cheuk Yin Lo,
Sangram S. Sisodia,
Paul Greengard,
Sam Gandy
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.8.3748
Subject(s) - amyloid precursor protein , golgi apparatus , endosome , amyloid precursor protein secretase , vesicle , cytosol , biology , microbiology and biotechnology , alzheimer's disease , transmembrane protein , biochemistry , amyloid (mycology) , guanosine , gtp' , chemistry , intracellular , receptor , medicine , endoplasmic reticulum , enzyme , membrane , botany , disease
beta-amyloid protein (A beta) formation was reconstituted in permeabilized neuroblastoma cells expressing human Alzheimer beta-amyloid precursor protein (beta APP) harboring the Swedish double mutation associated with familial early-onset Alzheimer disease. Permeabilized cells were prepared following metabolic labeling and incubation at 20 degrees C, a temperature that allows beta APP to accumulate in the trans-Golgi network (TGN) without concomitant A beta formation. Subsequent incubation at 37 degrees C led to the generation of A beta. A beta production in the TGN persisted even under conditions in which formation of nascent post-TGN vesicles was inhibited by addition of guanosine 5'-O-(3-thiotriphosphate), a nonhydrolyzable GTP analogue, or by omission of cytosol. These and other results indicate that vesicle budding and trafficking may not be required for proteolytic metabolism of beta APP to A beta, a process that includes "gamma-secretase" cleavage within the beta APP transmembrane domain.