In eukaryotic cells, selective breakdown of cellular proteins is ensured by their ubiquitination and subsequent degradation by the 26S Proteasome. The 26S Proteasome is a protease complex that selectively breaks down proteins that have been modified by polyubiquitin chains. It is made up of two multisubunit complexes: the 20S Proteasome chamber, which serves as the proteolytic core of the complex and two 19S regulatory particles which recognize and unfold ubiquitinated proteins. PSMC6 (proteasome (prosome, macropain) 26S subunit, ATPase 6), also known as P44, p42, SUG2, S10B or CADP44, is a regulatory component of the 26S proteasome. More specifically, PSMC6 is one of the six ATPase subunits of the 19S regulator base. It contains a leucine zipper motif and an AAA (ATPase associated with diverse cellular activities) domain and belongs to the AAA ATPase family of chaperone-like ATPases.