General Vesicular Transport Factor p115

General vesicular transport factor p115 (p115, encoded by USO1) is a 962-amino acid protein that functions as a vesicular anchor in the secretory pathway (UniProt: O60763). It is required for intercisternal transport within the Golgi stack and facilitates transcytotic fusion by holding vesicular and target membranes in proximity during vesicle docking and fusion events.

p115 operates within the endocytic and secretory transport system, which is essential for protein trafficking and cell-surface delivery. While no Mendelian disease associations are documented in UniProt, the protein's role in membrane dynamics and vesicular transport implicates it in general cellular homeostasis.

p115 has been identified in Alzheimer's disease proteomics studies (Chaparral AD proteomics). Analysis of post-mortem AD brain tissue across multiple subcellular fractions shows an ambiguous direction of change, with a mean log2 fold-change of −0.21 relative to age-matched controls, indicating minimal and inconsistent regulation across the examined fractions. This modest effect suggests p115 is not a primary target of AD-related proteome dysregulation, though its role in vesicular transport warrants monitoring in the context of broader secretory pathway dysfunction in neurodegeneration.