PSMA2
Description
The PSMA2 (proteasome 20S subunit alpha 2) is a protein-coding gene located on chromosome 7.
Proteasome subunit alpha type-2 is a protein encoded by the PSMA2 gene in humans. It is one of the 17 essential subunits that contribute to the complete assembly of the 20S proteasome complex, which is a multicatalytic proteinase complex with a highly ordered core structure. This barrel-shaped core is composed of four rings of 28 non-identical subunits: two outer rings each containing 7 alpha subunits, and two inner rings each containing 7 beta subunits. Three beta subunits (beta1, beta2, and beta5) possess proteolytic active sites with distinct substrate preferences. The human PSMA2 gene, also known as HC3, maps to chromosome band 6q27 and encodes a 25.9 kDa protein composed of 234 amino acids. The protein belongs to the peptidase T1A family and has a calculated theoretical pI of 6.77.
The PSMA2 protein is a component of the 20S core proteasome complex, which is involved in the proteolytic degradation of most intracellular proteins. The 20S proteasome forms the core of the 26S proteasome when associated with two 19S regulatory particles. The 26S proteasome degrades ubiquitinated proteins in an ATP-dependent manner, playing a crucial role in maintaining protein homeostasis by removing misfolded or damaged proteins, and proteins whose functions are no longer needed. The 20S proteasome also associates with PA200 or PA28, mediating ubiquitin-independent protein degradation, which is essential for processes such as spermatogenesis (20S-PA200 complex) and the generation of specific MHC class I-presented antigenic peptides (20S-PA28 complex).
PSMA2 is also known as HC3, MU, PMSA2, PSC2.
