Distinct anterograde trafficking pathways of BACE1 and amyloid precursor protein from the TGN and the regulation of amyloid-β production
Résumé
Processing of amyloid precursor protein (APP) by the β-secretase, BACE1, is the initial step of the amyloidogenic pathway to generate amyloid-β (Aβ). Although newly synthesised BACE1 and APP are transported along the secretory pathway, it is not known if BACE1 and APP share the same post-Golgi trafficking pathways or are partitioned into different transport routes. Here we demonstrate that BACE1 exits the Golgi in HeLa cells and primary neurons by a pathway distinct from the trafficking pathway for APP. Using the RUSH system, we show that BACE1 is transported from the TGN to the plasma membrane in an AP-1 and Arf1/4 dependent manner. Subsequently, BACE1 is endocytosed to early and recycling endosomes. Perturbation of BACE1 post-Golgi trafficking results in an increase in BACE1 cleavage of APP and increased production of both Aβ40 and Aβ42. These findings reveal that Golgi exit of BACE1 and APP in primary neurons is tightly regulated, resulting in their segregation along different transport routes, which limits APP processing.
Mots clés
anterograde transport
beta-secretase 1 (BACE1)
small GTPase
Arf1
Arf4
AP-1
AP-4
amyloid precursor protein (APP)
amyloid beta (Aβ)
trans-Golgi network
membrane transport
primary neurons Abbreviations: Aβ
beta-amyloid peptide
BACE1
beta site APP-cleaving enzyme
APP
amyloid precursor protein
AD
Alzheimer's disease
TGN
RUSH
retention using selective hooks
ER
endoplasmic reticulum
GFP
green fluorescent protein
PM
plasma membrane
TfR
transferrin receptor
TIRF
total internal reflection fluorescence microscopy
DIV
day in vitro
Domaines
Biologie cellulaireOrigine | Fichiers produits par l'(les) auteur(s) |
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