PSME3
Description
The PSME3 (proteasome activator subunit 3) is a protein-coding gene located on chromosome 17.
PSME3 (Proteasome activator complex subunit 3) is a protein encoded by the PSME3 gene in humans. It plays a crucial role in the function of the 26S proteasome, a multi-protein complex responsible for protein degradation. The 26S proteasome comprises two main components: the 20S core, responsible for protein breakdown, and the 19S regulator, which controls substrate recognition and protein unfolding. PSME3 is a subunit of the 11S regulator (also known as PA28), an alternative regulator that replaces the 19S regulator in a modified proteasome called the immunoproteasome. The 11S regulator is a ring-shaped complex composed of six gamma subunits, with PSME3 being one of them. PSME3's presence in the 11S regulator complex contributes to its function in the processing of peptides for presentation by class I MHC molecules, a crucial process in the immune response.
PSME3, also known as 11S REG-gamma, is a subunit of the 11S REG-gamma (also called PA28-gamma) proteasome regulator, a doughnut-shaped homoheptamer which associates with the proteasome. This complex activates the trypsin-like catalytic subunit of the proteasome while inhibiting the chymotrypsin-like and postglutamyl-preferring (PGPH) subunits. PSME3 facilitates the MDM2-p53/TP53 interaction, leading to ubiquitination- and MDM2-dependent proteasomal degradation of p53/TP53, limiting its accumulation and inhibiting apoptosis after DNA damage. PSME3 may also be involved in cell cycle regulation and mediates CCAR2 and CHEK2-dependent SIRT1 inhibition.
PSME3 is also known as HEL-S-283, Ki, PA28-gamma, PA28G, PA28gamma, REG-GAMMA.
