PSMB3
Description
The PSMB3 (proteasome 20S subunit beta 3) is a protein-coding gene located on chromosome 17.
PSMB3, also known as Proteasome subunit beta type-3, is a protein encoded by the PSMB3 gene in humans. It is one of the 17 essential subunits that make up the 20S proteasome complex. Along with other beta subunits, PSMB3 forms two heptameric rings within the proteasome, creating a chamber for protein degradation. The proteasome is responsible for recognizing and degrading proteins, including damaged proteins for quality control and regulatory proteins for cellular processes. PSMB3 is a member of the proteasome B-type (T1B) family, a 20S core beta subunit. The gene has 6 exons and is located on chromosome band 17q12. The protein is 23 kDa in size, composed of 205 amino acids, and has a calculated theoretical pI of 6.14. The proteasome is a complex with a highly ordered 20S core structure.
PSMB3 is a non-catalytic component of the 20S core proteasome complex, essential for the degradation of most intracellular proteins. The 20S proteasome forms the 26S proteasome by associating with two 19S regulatory particles, which then degrades ubiquitinated proteins in an ATP-dependent manner. This process plays a vital role in maintaining protein homeostasis by eliminating misfolded or damaged proteins, thus preventing cellular dysfunction, and removing proteins that are no longer needed. The 20S proteasome can also form complexes with PA200 or PA28, mediating ubiquitin-independent protein degradation, critical for pathways such as spermatogenesis (20S-PA200 complex) and generation of MHC class I-presented antigenic peptides (20S-PA28 complex).
PSMB3 is also known as HC10-II.
