Proteasome subunit alpha type-6

PSMA6 (proteasome subunit alpha type-6) is a core component of the 20S proteasome complex that catalyzes the ATP-dependent degradation of ubiquitinated proteins when associated with 19S regulatory particles, forming the 26S proteasome (UniProt: P60900). It also participates in ubiquitin-independent proteolysis when complexed with PA200 or PA28, contributing to diverse cellular processes including protein homeostasis and antigen presentation.

The 26S proteasome is essential for maintaining intracellular protein quality by removing misfolded, damaged, or functionally obsolete proteins across all tissues. Dysfunction of proteasomal degradation has been implicated in neurodegenerative diseases where protein aggregates accumulate (UniProt: P60900).

In Alzheimer's Disease, PSMA6 shows an ambiguous direction of change across brain fractions in post-mortem tissue (mean log2FC: −0.27; Chaparral AD proteomics). The modest and inconsistent effect across the three subcellular fractions examined suggests either subtle dysregulation or differential changes in specific cellular compartments, warranting further investigation into proteasome function in AD pathology.