PSMB11

PSMB11, or proteasome subunit beta type-11, is a protein encoded by the PSMB11 gene in humans. It is a component of the 20S core particle of the proteasome, a large protease complex responsible for the regulated degradation of intracellular proteins.

In the 20S proteasome, beta subunits form the proteolytic chamber. PSMB11 is produced as a precursor that undergoes proteolytic maturation to generate the mature beta subunit containing the N-terminal threonine active site, characteristic of proteasome proteases. Like other beta subunits, it contributes to peptide bond hydrolysis within proteins targeted for degradation.

PSMB11 participates in the constitutive proteasome core and, in combination with regulatory particles, contributes to the formation of the 26S proteasome in ubiquitin-dependent proteolysis. It is part of the highly conserved proteasome system present in eukaryotes, and its exact catalytic preferences may be similar to other beta subunits, though specific substrate selectivity can vary.

Expression studies indicate that PSMB11 is expressed in multiple human tissues, consistent with a role in general proteostasis. However, detailed tissue distribution and regulation under stress or immune conditions are less well characterized compared with immunoproteasome subunits.

Clinical relevance for PSMB11 is not as well established as for some other proteasome subunits. As with other components of the proteasome, alterations can impact protein homeostasis and have been implicated in diseases such as cancer and neurodegenerative disorders, but direct links to PSMB11 require further study.