19S proteasome regulatory particle (19S RP)

The 19S proteasome regulatory particle (RP), also known as PA700, is a multi-subunit complex that associates with the 20S core particle to form the 26S proteasome, the primary machinery for ATP-dependent protein degradation in eukaryotic cells (nih.gov, wikipedia.org). It is composed of approximately 19 subunits organized into two subassemblies: the base, which contains six AAA+ ATPases (Rpt1-6) and several non-ATPase subunits (Rpn1, Rpn2, Rpn13), and the lid, which contains the essential deubiquitinase Rpn11 (nih.gov, tum.de). The 19S RP performs critical functions including the recognition of polyubiquitinated substrates, removal of ubiquitin chains, and the unfolding and translocation of proteins into the 20S catalytic chamber (mdpi.com, nih.gov). Due to its central role in maintaining protein homeostasis, the 19S RP has become a significant therapeutic target, particularly in oncology for treating multiple myeloma and other malignancies that are sensitive to proteasome inhibition (nih.gov, patsnap.com). Small molecule inhibitors targeting specific 19S subunits, such as Rpn11 (e.g., capzimin) and Rpn13 (e.g., RA190), are being developed to overcome resistance to conventional 20S-targeting drugs like bortezomib (nih.gov, acs.org). Beyond cancer, the 19S RP is also implicated in neurodegenerative diseases and inflammatory conditions, making it a versatile focus for drug discovery (encyclopedia.pub, science.org).

Other names

PA70019S complex19S capProteasome regulatory particle26S proteasome regulatory subunit

Inhibition of deubiquitination (e.g., Rpn11 inhibition), blockade of ubiquitin recognition (e.g., Rpn13 inhibition), and inhibition of substrate unfolding and translocation through ATPase subunits.