protein
Amyloid-beta A4 precursor protein-binding family A member 1
Gene
APBA1
Organism
Homo sapiens(9606)
Length
837 aa
Mass
92,865 Da
APBA1 (amyloid-beta A4 precursor protein-binding family A member 1) is a 837-amino acid protein that functions in synaptic vesicle exocytosis by binding Munc18-1, a core component of the synaptic release machinery (UniProt: Q02410). It also modulates amyloid-beta precursor protein (APP) processing and participates in the LIN-10–LIN-2–LIN-7 complex, which associates with motor protein KIF17 to transport NMDA receptor-containing vesicles along microtubules.
APBA1 is primarily relevant to synaptic function and vesicular transport in the nervous system. The protein interacts with key elements of both exocytic and endosomal trafficking pathways, positioning it at the intersection of synaptic transmission and amyloid metabolism.
APBA1 is significantly downregulated in Alzheimer's disease brain tissue compared to age-matched controls (Chaparral AD proteomics). Quantitative proteomic analysis detected a mean log2 fold-change of −0.55 in post-mortem human AD brain across subcellular fractions, suggesting reduced protein abundance in the disease state. This downregulation may contribute to impaired synaptic function and altered APP processing observed in AD pathology.
Generated from the curated entity record below. May contain errors — verify against source links.
Proteomics Evidence · AD
↓ Down in ADP3
not detected
P2
not detected
S2
-0.546
S3
not detected
Mean log₂FC across detected fractions: -0.5458 (1 of 4 fractions detected)
Human post-mortem AD brain vs age-matched controls, TMT-labeled, 4 subcellular fractions (P2, P3, S2, S3), DDA proteomics.
Related Publications
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Dujardin Simon et al.Nature medicine2020PMID 32572268Deep Multilayer Brain Proteomics Identifies Molecular Networks in Alzheimer's Disease Progression.
Bai Bing et al.Neuron2020PMID 31926610A Multi-network Approach Identifies Protein-Specific Co-expression in Asymptomatic and Symptomatic Alzheimer's Disease.
Seyfried Nicholas T et al.Cell systems2017PMID 27989508Large-scale deep multi-layer analysis of Alzheimer's disease brain reveals strong proteomic disease-related changes not observed at the RNA level.
Johnson Erik C B et al.Nature neuroscience2022PMID 35115731Organization and regulation of gene transcription.
Cramer PatrickNature2019PMID 31462772
Function
Putative function in synaptic vesicle exocytosis by binding to Munc18-1, an essential component of the synaptic vesicle exocytotic machinery. May modulate processing of the amyloid-beta precursor protein (APP) and hence formation of APP-beta. Component of the LIN-10-LIN-2-LIN-7 complex, which associates with the motor protein KIF17 to transport vesicles containing N-methyl-D-aspartate (NMDA) receptor subunit NR2B along microtubules (By similarity)
Sources
Last updated 5/8/2026, 6:32:12 AM