Proteasome activator PA28 (IPR009077)

Short name: Proteasome_activ_PA28

Overlapping homologous superfamilies

Family relationships



The 20S proteasome is a multicatalytic complex that is responsible for the non-lysosomal degradation of intracellular proteins. The proteasome is composed of a catalytic core that is regulated by protein complexes, which bind to the ends of the cylindrical core structure. One of these regulatory complexes is the PA28 activator complex (also known as the 11S regulator, or REG), a ring-shaped hexameric structure that enhances the peptidase activity of the core enzyme. Three REG subunits have been isolated, REGalpha, REGbeta and REGgamma. REGalpha and REGbeta preferentially form a heteromeric complex with alternating alpha and beta subunits. The structure of the human REGalpha subunit reveals a heptameric barrel-shaped assembly containing a central channel [PMID: 9403698]. The binding of REG is thought to create a pore through with substrates and products can pass.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0008537 proteasome activator complex

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.