a proteasomal protein of the T1B peptidase family. The proteasome is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with Arg, Phe, Tyr, Leu, and Glu adjacent to the leaving group at neutral or slightly basic pH. Proteasomes are distributed throughout eukaryotic cells at a high concentration and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. This catalytic subunit is downregulated by gamma interferon and proteolytic processing is required to generate a mature subunit. Not present in the immunoproteasome and is replaced by catalytic subunit 2i (proteasome beta 10 subunit). Note: This description may include information from UniProtKB.
Protein type: Protease; EC 18.104.22.168; Proteasome complex
Molecular Function: threonine endopeptidase activity; protein binding
Biological Process: positive regulation of ubiquitin-protein ligase activity during mitotic cell cycle; negative regulation of ubiquitin-protein ligase activity during mitotic cell cycle; protein polyubiquitination; viral reproduction; apoptosis; antigen processing and presentation of exogenous peptide antigen via MHC class I, TAP-dependent; DNA damage response, signal transduction by p53 class mediator resulting in cell cycle arrest; regulation of apoptosis; antigen processing and presentation of peptide antigen via MHC class I; regulation of ubiquitin-protein ligase activity during mitotic cell cycle; anaphase-promoting complex-dependent proteasomal ubiquitin-dependent protein catabolic process; antigen processing and presentation of exogenous peptide antigen via MHC class I; gene expression; mitotic cell cycle; regulation of amino acid metabolic process; G1/S transition of mitotic cell cycle; negative regulation of apoptosis
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.