Vacuolar protein sorting-associated protein 26B

Vacuolar protein sorting-associated protein 26B (VPS26B) is a component of the retromer cargo-selective complex, which functions to prevent missorting of transmembrane cargo proteins destined for lysosomal degradation (UniProt: Q4G0F5). The protein participates in multiple retrograde and recycling pathways, including SNX-BAR retromer-mediated transport from endosomes to the trans-Golgi network and SNX27-retromer-mediated endosome-to-plasma membrane trafficking of diverse cargo proteins. VPS26B acts redundantly with VPS26A in endocytic recycling of glucose transporter SLC2A1.

VPS26B is expressed broadly and involved in cellular trafficking and protein recycling mechanisms. No specific disease associations are documented in UniProt for this protein.

In Alzheimer's Disease, VPS26B is consistently downregulated in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of −0.67 (Chaparral AD proteomics). This downregulation was measured across subcellular fractions from human brain tissue using quantitative mass spectrometry, suggesting reduced retromer function and potentially impaired endosomal cargo recycling in the AD brain pathology.