PSMD9 cDNA Clone – 26s Proteasome Non-Atpase Regulatory Subunit 9 Isoform 1

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. This gene encodes a non-ATPase subunit of the 19S regulator. Three transcript variants encoding two different isoforms have been found for this gene. [provided by RefSeq, May 2012]

PSMD9: Acts as a chaperone during the assembly of the 26S proteasome, specifically of the base subcomplex of the PA700/19S regulatory complex (RC). During the base subcomplex assembly is part of an intermediate PSMD9:PSMC6:PSMC3 module, also known as modulator trimer complex; PSMD9 is released during the further base assembly process. Belongs to the proteasome subunit p27 family. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Proteasome complex; Motility/polarity/chemotaxis; Protease

Chromosomal Location of Human Ortholog: 12q24.31-q24.32

Cellular Component: nucleoplasm; proteasome regulatory particle; cytoplasm; cytosol; nucleus

Molecular Function: protein binding; transcription coactivator activity; bHLH transcription factor binding

Biological Process: positive regulation of ubiquitin-protein ligase activity during mitotic cell cycle; ubiquitin-dependent protein catabolic process; negative regulation of ubiquitin-protein ligase activity during mitotic cell cycle; protein polyubiquitination; viral reproduction; apoptosis; positive regulation of transcription, DNA-dependent; positive regulation of insulin secretion; 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; negative regulation of insulin secretion; 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