Proteasome subunit beta type-8 (LMP7) (LMP7)

Proteasome subunit beta type-8 (PSMB8), commonly known as LMP7, is a catalytic subunit of the immunoproteasome, a specialized protein degradation complex primarily expressed in hematopoietic cells and induced by pro-inflammatory cytokines like interferon-gamma [UniProt P28062]. LMP7 replaces the constitutive beta-5 subunit to modify the proteasome's cleavage specificity, favoring the generation of peptides with hydrophobic C-termini that are optimal for MHC class I antigen presentation [PubMed: 23413443]. This process is critical for the activation of CD8+ T-cell-mediated immune responses and the regulation of cytokine production, including IL-6 and TNF-alpha [NCBI Gene: 5696]. Dysregulation or overexpression of LMP7 is implicated in various autoimmune and inflammatory diseases, such as rheumatoid arthritis and systemic lupus erythematosus, as well as certain cancers like multiple myeloma [PubMed: 30635415]. Furthermore, mutations in the PSMB8 gene are the primary cause of autoinflammatory syndromes like CANDLE (Chronic Atypical Neutrophilic Dermatosis with Lipodystrophy and Elevated temperature) [NIH: GARD]. Therapeutic targeting of LMP7 with selective inhibitors like zetomipzomib (KZR-616) aims to modulate immune activity while minimizing the systemic toxicity associated with non-selective proteasome inhibitors [Kezar Life Sciences]. This selective approach offers a promising strategy for treating chronic inflammatory conditions by dampening the production of multiple pro-inflammatory cytokines simultaneously.

Other names

PSMB8Beta5iRING10Low molecular mass protein 7Proteasome catalytic subunit 3iMacropain subunit C13

Selective inhibition of the chymotrypsin-like catalytic activity of the immunoproteasome subunit LMP7, leading to altered peptide presentation and reduced pro-inflammatory cytokine secretion.