A 26 S protease subunit that binds ubiquitin conjugates.
Ubiquitin-mediated proteolysis provides an important mechanism for regulating a variety of cellular processes. Ubiquitin-conjugated proteins are degraded by a 26 S protease that contains more than 30 different subunits. Of these, a single 50-kDa polypeptide, subunit 5, specifically binds ubiquitin-lysozyme conjugates. Binding is inhibited by short polymeric chains of ubiquitin but not by ubiquitin monomers or by lysozyme. In addition, subunit 5 binds free ubiquitin chains with efficient association requiring at least four ubiquitins. Thus, proteins conjugated to polymers of ubiquitin may be selected for degradation by a single subunit of the 26 S protease complex.
Deveraux
Q
Q
Department of Biochemistry, University of Utah School of Medicine, Salt lake City 84132.
Ustrell
V
V
Pickart
C
C
Rechsteiner
M
M
D001667:Binding, Competitive; D006801:Humans; D010447:Peptide Hydrolases / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D014452:Ubiquitins / Q000378:metabolism*
D014452:Ubiquitins; D010447:Peptide Hydrolases; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease