Proteasome 26S subunit ATPase 1 (PSMC1)

Proteasome 26S subunit ATPase 1 (PSMC1) is an essential enzymatic subunit of the 19S regulatory particle’s base within the 26S proteasome, a major multiprotein complex responsible for ATP-dependent degradation of ubiquitinated proteins in eukaryotic cells. As a AAA+ ATPase, PSMC1 (also known as 26S proteasome AAA-ATPase subunit Rpt2) participates in unfolding and translocating target proteins into the 20S proteolytic core, coupling ATP hydrolysis to protein degradation. This process is central to protein homeostasis, cell cycle regulation, apoptosis, DNA repair, and MHC class I antigen presentation. Mutations or dysregulation of PSMC1 and the proteasome pathway can contribute to a range of diseases including cancer, neurodegenerative disorders, and inherited syndromes. While PSMC1 itself is not typically directly targeted by drugs, broad-spectrum proteasome inhibitors (such as bortezomib) impact its function as part of the 26S proteasome complex.

Other names

26S proteasome regulatory subunit 426S proteasome AAA-ATPase subunit Rpt2P26s4S4p56RPT2NEDGTHP26S4PRS4proteasome (prosome, macropain) 26S subunit, ATPase 1proteasome 26S ATPase subunit 1

Proteasome inhibition (by blocking ATPase and/or proteolytic activity within the proteasome complex, leading to accumulation of ubiquitinated proteins, cell cycle arrest, and apoptosis); Disruption of protein homeostasis (anticancer; e.g., through proteasome inhibitors in multiple myeloma)