Proteasome subunit beta type-6 (PSMB6) (PSMB6)

The 20S proteasome beta-1 subunit, encoded by the PSMB6 gene, is one of the three catalytic subunits located within the 20S core particle of the proteasome complex [1, 3]. It is characterized by its caspase-like or peptidyl-glutamyl peptide-hydrolyzing (PGPH) activity, which enables the cleavage of peptide bonds following acidic amino acid residues [3, 7]. As a central component of the ubiquitin-proteasome system (UPS), this subunit is essential for the degradation of misfolded, damaged, and short-lived regulatory proteins, thereby maintaining cellular protein homeostasis [1, 6]. In disease states, particularly hematological malignancies like multiple myeloma, the proteasome's activity is often upregulated to support rapid cell proliferation and survival [6, 14]. Therapeutic agents such as bortezomib and marizomib target the catalytic sites of the proteasome, including the beta-1 subunit, to induce proteotoxic stress and trigger apoptosis in cancer cells [6, 9]. Beyond oncology, the beta-1 subunit is a subject of interest in neurodegenerative diseases and autoimmune conditions, where proteasome dysfunction contributes to protein aggregation and inflammatory signaling [5, 12].

Other names

20S proteasome subunit beta-1Proteasome subunit beta 1Macropain delta chainMulticatalytic endopeptidase complex delta chainProteasome delta chainProteasome subunit YLMPYDELTA

Inhibition of the catalytic activity of the 20S proteasome core particle, specifically the caspase-like (peptidyl-glutamyl peptide-hydrolyzing) activity of the beta-1 subunit, leading to the accumulation of polyubiquitinated proteins, proteotoxic stress, and induction of apoptosis.