Proteasome Activator Subunit 3 (PSME3) Antibody – Rabbit Polyclonal

The 26S proteasome is a multicatalytic proteinase complex with a highly ordered structure composed of 2 complexes, a 20S core and a 19S regulator. The 20S core is composed of 4 rings of 28 non-identical subunits; 2 rings are composed of 7 alpha subunits and 2 rings are composed of 7 beta subunits. The 19S regulator is composed of a base, which contains 6 ATPase subunits and 2 non-ATPase subunits, and a lid, which contains up to 10 non-ATPase subunits. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. An essential function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. The immunoproteasome contains an alternate regulator, referred to as the 11S regulator or PA28, that replaces the 19S regulator. Three subunits (alpha, beta and gamma) of the 11S regulator have been identified. This gene encodes the gamma subunit of the 11S regulator. Six gamma subunits combine to form a homohexameric ring. Alternate splicing results in multiple transcript variants. [provided by RefSeq, May 2012]

PSME3: a protein implicated in immunoproteasome assembly and required for efficient antigen processing. The PA28 activator complex enhances the generation of class I binding peptides by altering the cleavage pattern of the proteasome. Homohexamer. Significantly elevated in colorectal cancer patients compared with healthy donors and patients with benign bowel disease. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Nuclear receptor co-regulator; Protease; Proteasome complex

Chromosomal Location of Human Ortholog: 17q21.31

Cellular Component: cytoplasm; cytosol; membrane; nucleoplasm; nucleus; proteasome activator complex; proteasome complex

Molecular Function: identical protein binding; p53 binding; protein binding

Biological Process: anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent; apoptosis; MAPK cascade; negative regulation of ubiquitin-protein ligase activity involved in mitotic cell cycle; positive regulation of ubiquitin-protein ligase activity during mitotic cell cycle; post-translational protein modification; proteasomal ubiquitin-dependent protein catabolic process; protein deubiquitination; protein polyubiquitination; regulation of cellular amino acid metabolic process; regulation of mRNA stability; SCF-dependent proteasomal ubiquitin-dependent protein catabolic process; stimulatory C-type lectin receptor signaling pathway; T cell receptor signaling pathway; transmembrane transport; tumor necrosis factor-mediated signaling pathway; Wnt receptor signaling pathway, planar cell polarity pathway