Human Proteasome Activator Complex Subunit 3, PSME3 ELI

Subunit of the 11S REG-gamma (also called PA28-gamma) proteasome regulator, a doughnut-shaped homoheptamer which associates with the proteasome.

11S REG-gamma activates the trypsin-like catalytic subunit of the proteasome but inhibits the chymotrypsin-like and postglutamyl-preferring (PGPH) subunits.

Facilitates the MDM2-p53/TP53 interaction which promotes ubiquitination- and MDM2-dependent proteasomal degradation of p53/TP53, limiting its accumulation and resulting in inhibited apoptosis after DNA damage.

May also be involved in cell cycle regulation.

Mediates CCAR2 and CHEK2-dependent SIRT1 inhibition (PubMed:25361978).