Transmembrane 9 Superfamily Member 3 (TM9SF3)

TM9SF3 is a transmembrane protein of 589 amino acids encoded by the TM9SF3 gene in humans (UniProt: Q9HD45). It belongs to the transmembrane 9 superfamily and is predicted to have roles in membrane trafficking or protein transport based on its structural classification, though specific molecular function details are limited in available annotation.

TM9SF3 expression and tissue localization patterns have not been extensively characterized in the UniProt database. No disease associations are documented in standard disease annotation resources, suggesting this protein has received limited clinical investigation to date.

In the context of Alzheimer's Disease, TM9SF3 is modestly upregulated in post-mortem AD brain tissue compared to age-matched controls (Chaparral AD proteomics). The mean log2 fold-change is 0.3629, representing a small but consistent increase detected across human post-mortem AD brain subcellular fractions using TMT-labeled, data-dependent acquisition proteomics. The biological significance of this modest elevation in AD pathology remains to be determined.