Dataset Information

Visualizing APP and BACE-1 approximation in neurons yields insight into the amyloidogenic pathway.

ABSTRACT: Cleavage of amyloid precursor protein (APP) by BACE-1 (?-site APP cleaving enzyme-1) is the rate-limiting step in amyloid-? (A?) production and a neuropathologic hallmark of Alzheimer's disease; thus, physical approximation of this substrate-enzyme pair is a crucial event with broad biological and therapeutic implications. Despite much research, neuronal locales of APP and BACE-1 convergence and APP cleavage remain unclear. Here we report an optical assay, based on fluorescence complementation, for visualizing in cellulo APP-BACE-1 interactions as a simple on/off signal. Combining this with other assays tracking the fate of internalized APP in hippocampal neurons, we found that APP and BACE-1 interacted in both biosynthetic and endocytic compartments, particularly along recycling microdomains such as dendritic spines and presynaptic boutons. In axons, APP and BACE-1 were cotransported, and they also interacted during transit. Finally, our assay revealed that the Alzheimer's disease-protective 'Icelandic' mutation greatly attenuates APP-BACE-1 interactions, suggesting a mechanistic basis for protection. Collectively, the data challenge canonical models and provide concrete insights into long-standing controversies in the field.

SUBMITTER: Das U

PROVIDER: S-EPMC4782935 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Visualizing APP and BACE-1 approximation in neurons yields insight into the amyloidogenic pathway.

Das Utpal U Wang Lina L Ganguly Archan A Saikia Junmi M JM Wagner Steven L SL Koo Edward H EH Roy Subhojit S

Nature neuroscience 20151207 1

Cleavage of amyloid precursor protein (APP) by BACE-1 (β-site APP cleaving enzyme-1) is the rate-limiting step in amyloid-β (Aβ) production and a neuropathologic hallmark of Alzheimer's disease; thus, physical approximation of this substrate-enzyme pair is a crucial event with broad biological and therapeutic implications. Despite much research, neuronal locales of APP and BACE-1 convergence and APP cleavage remain unclear. Here we report an optical assay, based on fluorescence complementation, ...[more]

PMID: 26642089

Similar Datasets

Project description:Alzheimer's disease (AD) is characterized by an accumulation of Amyloid-? (A?), released by sequential proteolytic processing of the amyloid precursor protein (APP) by ? - and ?-secretase. A? peptides can aggregate, leading to toxic A? oligomers and amyloid plaque formation. A? accumulation is not only dependent on de novo synthesis but also on A? degradation. Neprilysin (NEP) is one of the major enzymes involved in A? degradation. Here we investigate the molecular mechanism of NEP regulation, which is up to now controversially discussed to be affected by APP processing itself. We found that NEP expression is highly dependent on the APP intracellular domain (AICD), released by APP processing. Mouse embryonic fibroblasts devoid of APP processing, either by the lack of the catalytically active subunit of the ?-secretase complex [presenilin (PS) 1/2] or by the lack of APP and the APP-like protein 2 (APLP2), showed a decreased NEP expression, activity and protein level. Similar results were obtained by utilizing cells lacking a functional AICD domain (APP?CT15) or expressing mutations in the genes encoding for PS1. AICD supplementation or retransfection with an AICD encoding plasmid could rescue the down-regulation of NEP further strengthening the link between AICD and transcriptional NEP regulation, in which Fe65 acts as an important adaptor protein. Especially AICD generated by the amyloidogenic pathway seems to be more involved in the regulation of NEP expression. In line, analysis of NEP gene expression in vivo in six transgenic AD mouse models (APP and APLP2 single knock-outs, APP/APLP2 double knock-out, APP-swedish, APP-swedish/PS1?exon9, and APP?CT15) confirmed the results obtained in cell culture. In summary, in the present study we clearly demonstrate an AICD-dependent regulation of the A?-degrading enzyme NEP in vitro and in vivo and elucidate the underlying mechanisms that might be beneficial to develop new therapeutic strategies for the treatment of AD.

Dataset Information

Visualizing APP and BACE-1 approximation in neurons yields insight into the amyloidogenic pathway.

Publications

Visualizing APP and BACE-1 approximation in neurons yields insight into the amyloidogenic pathway.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure