PSMA3 Protein, Human (His)

PSMA3, a crucial component of the 20S core proteasome complex, plays a pivotal role in the ATP-dependent degradation of ubiquitinated proteins, contributing to the maintenance of protein homeostasis. When associated with two 19S regulatory particles, it forms the 26S proteasome, which is integral in removing misfolded or damaged proteins to preserve cellular functions. In conjunction with PA200 or PA28, the 20S proteasome facilitates ubiquitin-independent protein degradation, vital for processes like spermatogenesis and the generation of MHC class I-presented antigenic peptides. PSMA3 also binds to the C-terminus of CDKN1A, mediating its degradation, and negatively regulates the membrane trafficking of the cell-surface thromboxane A2 receptor isoform 2. The 26S proteasome, comprising a 20S proteasome core and two 19S regulatory subunits, functions as a barrel-shaped complex made of 28 subunits arranged in four stacked rings. The proteolytic activity of the 20S core is executed by three beta-subunits, PSMB5, PSMB6, and PSMB7. PSMA3 further engages in protein interactions with AURKB, CDKN1A, MDM2, RB1, TBXA2R isoform 2, and DNAJB2, underscoring its versatile roles in cellular regulatory pathways.