Human LMP7/PSMB8 Alexa Fluor™ Plus 555‑conjugated Antibody

PSMB8 (Proteasome Subunit beta type-8; Also beta 5i, RING10/Y2 and LMP7) is a 23-24 kDa member of the peptidase T1B family of molecules. It is expressed both constitutively and inducibly by IFN-gamma in a wide variety of cells, including immature dendritic cells, preadipocytes, CD4⁺ T cells and monocytes. PSMB8 contributes to the 700 kDa, 20S proteasome catalytic complex, a dynamic intracellular structure that participates in ATP-dependent proteolytic activity. PSMB8 qualifies as a beta -type, i (immuno)-type proteasome, meaning it both plays a chymotrypsin-like role in the turnover of proteins, and is found in cytokine-responsive cells. The peptides generated through PSMB8 activity are used as immunogens by MHC-I molecules. PSMB8 activity is dependent upon the removal of the PSMB8 precursor prosequence, an action that exposes a critical internal Thr residue. Human PSMB8 is synthesized as a 28-29 kDa, 276 amino acid (aa) proprecursor. It contains a 72 aa autocleavable propeptide plus a 204 aa mature region. The mature region shows no identifiable standard structural motifs. There is one alternative splice form that shows a 45 aa substitution for aa 1-49. This isoform does not appear to participate in formation of a proteosome. Over aa 73-276, human PSMB8 shares 92% aa sequence identity with mouse PSMB8.