AP-1 complex subunit mu-1

AP-1 complex subunit mu-1 (AP1M1) is a core component of the clathrin-associated adaptor protein complex 1, functioning in protein sorting at the trans-Golgi network and endosomes by mediating clathrin recruitment and recognition of cargo sorting signals (UniProt: Q9BXS5). The protein participates in vesicular trafficking pathways critical for intracellular protein transport and localization across multiple cellular compartments.

AP1M1 shows relevance to Alzheimer's Disease based on proteomics analysis of post-mortem AD brain tissue. In a TMT-labeled quantitative study comparing AD patients to age-matched controls across four subcellular fractions (P2, P3, S2, S3), AP1M1 displayed an ambiguous direction of change, with a mean log2 fold-change of −0.25 (Chaparral AD proteomics). This modest downward trend with inconsistent directionality across fractions suggests potential alterations in AP1M1 abundance or subcellular distribution in AD pathology, though the biological significance remains unclear without additional functional validation.