Recruiting substrates to cullin 4-dependent ubiquitin ligases by DDB1.
The ubiquitin-proteasome system is the major pathway by which cells target proteins for degradation in a specific manner. The E3 ubiquitin ligase, which brings targeted proteins (substrates) and activated ubiquitin in close proximity, enabling covalent conjugation of ubiquitin to the substrate, is an essential component of this system. Of the E3 ligases, the cullin (CUL) ligases are of high interest because of their capacity to form multiple distinct E3 complexes to ubiquitinate a potentially large number of substrates. Of the six closely related cullins, very little is known about how specific substrates are recruited to CUL4-dependent ligases. A recent paper in Nature Cell Biology may shed some light on this issue as well as on the function of DDB1, a damaged-DNA binding protein that has long been associated with DNA repair.
McCall
Chad M
CM
Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, and Program in Molecular Biology and Biotechnology, University of North Carolina at Chapel Hill, North Carolina, USA.
Hu
Jian
J
Xiong
Yue
Y
D000818:Animals; D044842:Cullin Proteins / Q000502:physiology*; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D046988:Proteasome Endopeptidase Complex / Q000502:physiology; D013379:Substrate Specificity; D025801:Ubiquitin / Q000378:metabolism; D044764:Ubiquitin-Activating Enzymes / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*
D044842:Cullin Proteins; C091435:DDB1 protein, human; D004268:DNA-Binding Proteins; D025801:Ubiquitin; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex; D044764:Ubiquitin-Activating Enzymes