PSMC4
Description
The PSMC4 (proteasome 26S subunit, ATPase 4) is a protein-coding gene located on chromosome 19.
PSMC4, also known as 26S proteasome regulatory subunit 6B, is an enzyme encoded by the PSMC4 gene in humans. It is one of the 19 essential subunits of the 26S proteasome complex, a large protein complex involved in degrading proteins. PSMC4 is an ATPase subunit belonging to the AAA family, which have chaperone-like activity. It interacts with several proteins, including an orphan member of the nuclear hormone receptor superfamily highly expressed in the liver and gankyrin, a liver oncoprotein. Two transcript variants encoding different isoforms of PSMC4 have been identified. The PSMC4 gene contains 11 exons and is located on chromosome band 19q13.11-q13.13. The human PSMC4 protein is 47kDa in size and composed of 418 amino acids. Its calculated theoretical pI is 5.09. The 26S proteasome complex consists of a 20S core particle (CP) and one or two 19S regulatory particles (RP) on either side of the CP. The CP and RPs have distinct structures and functions. The CP has three types of proteolytic activities: caspase-like, trypsin-like, and chymotrypsin-like activities.
PSMC4 is a component of the 26S proteasome, a multi-protein complex essential for degrading ubiquitinated proteins. This process is ATP-dependent and plays a critical role in maintaining cellular protein homeostasis by removing misfolded, damaged, or unnecessary proteins. This removal is crucial for various cellular processes, including cell cycle progression, apoptosis, and DNA damage repair. PSMC4 belongs to a ring of six AAA ATPases, which unfold the ubiquitinated target proteins before they are translocated into the proteolytic chamber for degradation into peptides.
PSMC4 is also known as MIP224, RPT3, S6, TBP-7, TBP7.
