Proteasome activator complex subunit 1 (PSME1)

Proteasome activator complex subunit 1 (PSME1) encodes the alpha subunit of the 11S proteasome regulator, PA28. The PA28 complex is an alternative regulator of the 20S core proteasome, particularly active in the immunoproteasome, where it is involved in the processing of peptides presented by MHC class I molecules. PSME1 is induced by interferon-gamma and forms a heterohexameric ring with PA28beta subunits, enhancing the generation of class I MHC-binding peptides by altering proteasome cleavage specificity. The PA28/11S regulator is central to immune surveillance and antigen processing, though not a classic pharmaceutical target itself. Disruption of PSME1 can alter immune responses and proteostasis, with potential disease roles in cancer, immunity, and infection.

Other names

PA28alphaIFI5111REG-alphaIGUP I-5111PA28a11S regulator complex subunit alphaActivator of multicatalytic protease subunit 1Interferon gamma up-regulated I-5111 proteinProteasome activator 28 subunit alphaPA28AREGalpha29-kD MCP activator subunitEpididymis secretory sperm binding protein Li 129mInterferon-gamma-inducible protein 5111Proteasome (prosome, macropain) activator subunit 1 (PA28 alpha)

Not directly targeted by approved drugs; theoretically, modulation would affect proteasome activity and antigen presentation, possibly altering immune cell responses and proteostasis