COMM domain-containing protein 1

COMMD1 (COMM domain-containing protein 1) is a 190-amino acid scaffold protein that functions as a core component of the commander complex, which mediates endosomal recycling of transmembrane cargos (UniProt: Q8N668). The protein regulates multiple cellular processes including cullin-RING E3 ubiquitin ligase activity, NF-κB signaling through RELA ubiquitination and degradation, and ion channel trafficking via modulation of sodium channel and CFTR surface expression. COMMD1 also participates in copper homeostasis and HIF1A-dependent transcriptional regulation.

COMMD1 is broadly expressed and functionally linked to cellular transport, proteostasis, and signaling pathways relevant to neuronal function and cellular stress responses. Its roles in regulating NF-κB activity and copper metabolism suggest potential relevance to neuroinflammation and metal ion homeostasis in the brain.

In Alzheimer's disease, COMMD1 is upregulated in post-mortem human brain tissue compared to age-matched controls (Chaparral AD proteomics), with a mean log2 fold-change of 0.31 across subcellular fractions. This modest elevation may reflect altered endosomal recycling or changes in ubiquitin-mediated protein degradation pathways implicated in AD pathophysiology, though the functional significance of this upregulation requires further investigation.