The proteasome is a multicatalytic proteinase complex with a highly ordered ring-shaped 20S core structure. The core structure 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. 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 member of the proteasome B-type family, also known as the T1B family, that is a 20S core beta subunit. Multiple alternatively spliced transcript variants encoding distinct isoforms have been found for this gene. [provided by RefSeq, Dec 2010]
Forensic Context
A study in humans demonstrated that the PSMB2 exhibits increased polyadenylation in viral compared to bacterial sepsis in whole blood samples [He et al. DOI:10.1186/s12879-025-11078-z]. In a separate investigation, the PSMB2 was identified as a human housekeeping gene with highly uniform and strong expression across 16 normal tissues, making it a proposed candidate for calibration in genomic studies [Eisenberg & Levanon DOI:10.1016/j.tig.2013.05.010]. A study in mice demonstrated that the PSMB2 (Psmb2) was identified as a highly stable reference gene in white adipose tissue at both 3 and 7 days post-trauma in a model combining traumatic brain injury and femoral fracture [Otto et al. DOI:10.1038/s41598-020-71895-x]. Its validated stability supports its recommended use, particularly in combination with Ppia, for reliable qRT-PCR normalization when analyzing systemic effects in secondary organs following multiple trauma.