PSME4
Description
The PSME4 (proteasome activator subunit 4) is a protein-coding gene located on chromosome 2.
Proteasome activator complex subunit 4 is a protein that in humans is encoded by the PSME4 gene.
PSME4, also known as PA200, is involved in the ATP- and ubiquitin-independent degradation of core histones. It specifically recognizes acetylated histones via its bromodomain-like (BRDL) region, activating the proteasome by opening the gated channel for substrate entry. PSME4 binds to the core proteasome through its C-terminus, occupying the same binding sites as the proteasomal ATPases and opening the proteasome's closed structure via an active gating mechanism. As a component of the spermatoproteasome, PSME4 binds to acetylated histones and promotes histone degradation during spermatogenesis, contributing to histone exchange. PSME4 also plays a role in DNA damage response in somatic cells by promoting histone degradation following DNA double-strand breaks.
PSME4 is also known as PA200.
