Proteasome Subunit Beta Type 11 (PSMb11)

Proteasomes generate peptides that are presented by major histocompatibility complex (MHC) I molecules to other cells of the immune system. Proteolysis is conducted by 20S proteasomes, complexes of 28 subunits arranged as a cylinder in 4 heteroheptameric rings: alpha-1 to -7, beta-1 to -7, beta-1 to -7, and alpha-1 to -7. The catalytic subunits are beta-1 (PSMB6), beta-2 (PSMB7), and beta-5 (PSMB5). Three additional subunits, beta-1i (PSMB9), beta-2i (PSMB10), and beta-5i (PSMB8), are induced by gamma-interferon (IFNG) and are preferentially incorporated into proteasomes to make immunoproteasomes. PSMB11, or beta-5t, is a catalytic subunit expressed exclusively in cortical thymic epithelial cells.