Proteasome subunit beta type-9 (LMP2) (LMP2)

Proteasome subunit beta type-9 (PSMB9), also known as LMP2, is a catalytic subunit of the immunoproteasome, a specialized proteolytic complex primarily expressed in hematopoietic cells or induced by pro-inflammatory cytokines like interferon-gamma (UniProt: P28065). It replaces the constitutive beta-1 subunit (PSMB6) to enhance the generation of peptides suitable for MHC class I antigen presentation, thereby modulating the adaptive immune response (PubMed: 22226215). LMP2 is crucial for the degradation of intracellular proteins and the regulation of signaling pathways, including the NF-kappaB pathway, which drives the production of pro-inflammatory cytokines (PubMed: 19749781). Overexpression or dysregulation of LMP2 is linked to autoimmune diseases such as systemic lupus erythematosus and rheumatoid arthritis, as well as certain cancers (PubMed: 28655140). Consequently, LMP2 has emerged as a promising therapeutic target for selective immunomodulation. Small molecule inhibitors like zetomipzomib (KZR-616) target LMP2 to reduce inflammation while minimizing the systemic toxicity typically associated with non-selective proteasome inhibitors like bortezomib (PubMed: 31110111).

Other names

PSMB9Low molecular mass polypeptide 2Proteasome subunit beta-1iRING12Beta1i

Selective inhibition of the chymotrypsin-like catalytic activity of the immunoproteasome subunit LMP2, which prevents the processing of pro-inflammatory mediators and alters MHC class I peptide presentation (PubMed: 19749781, 31110111).