Structural highlightsFunctionCUE1_YEAST Component of the endoplasmic reticulum-associated protein degradation (ERAD) pathway. Recruits the soluble ubiquitin-conjugating enzyme UBC7 to the cytoplasmic face of the endoplasmic reticulum membrane where it functions in degradation of misfolded or regulated proteins localized in the endoplasmic reticulum (ER) lumen or membrane via the ubiquitin-proteasome system. Targets the E2 conjugating enzyme UBC7 to the DOA10 ubiquitin ligase complex, which is part of the ERAD-C pathway responsible for the rapid degradation of membrane proteins with misfolded cytoplasmic domains, and to the HRD1 ubiquitin ligase complex, which is part of the ERAD-L and ERAD-M pathways responsible for the rapid degradation of soluble lumenal and membrane proteins with misfolded lumenal domains (ERAD-L), or ER-membrane proteins with misfolded transmembrane domains (ERAD-M). Has also a role in cold adaptation, perhaps through effects on sterol biosynthesis.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Publication Abstract from PubMed
Ubiquitin conjugation is an essential process modulating protein function in eukaryotic cells. Surprisingly, little is known about how the progressive assembly of ubiquitin chains is managed by the responsible enzymes. Only recently has ubiquitin binding activity emerged as an important factor in chain formation. The Ubc7 activator Cue1 carries a ubiquitin binding CUE domain that substantially stimulates K48-linked polyubiquitination mediated by Ubc7. Our results from NMR-based analysis and in vitro ubiquitination reactions point out that two parameters accelerate ubiquitin chain assembly: the increasing number of CUE binding sites and the position of CUE binding within a growing chain. In particular, interactions with a ubiquitin moiety adjacent to the acceptor ubiquitin facilitate chain elongation. These data indicate a mechanism for ubiquitin binding in which Cue1 positions Ubc7 and the distal acceptor ubiquitin for rapid polyubiquitination. Disrupting this mechanism results in dysfunction of the ERAD pathway by a delayed turnover of substrates.
The CUE Domain of Cue1 Aligns Growing Ubiquitin Chains with Ubc7 for Rapid Elongation.,von Delbruck M, Kniss A, Rogov VV, Pluska L, Bagola K, Lohr F, Guntert P, Sommer T, Dotsch V Mol Cell. 2016 Jun 16;62(6):918-28. doi: 10.1016/j.molcel.2016.04.031. Epub 2016 , Jun 2. PMID:27264873[12]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
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- ↑ Loertscher J, Larson LL, Matson CK, Parrish ML, Felthauser A, Sturm A, Tachibana C, Bard M, Wright R. Endoplasmic reticulum-associated degradation is required for cold adaptation and regulation of sterol biosynthesis in the yeast Saccharomyces cerevisiae. Eukaryot Cell. 2006 Apr;5(4):712-22. PMID:16607018 doi:http://dx.doi.org/10.1128/EC.5.4.712-722.2006
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- ↑ von Delbruck M, Kniss A, Rogov VV, Pluska L, Bagola K, Lohr F, Guntert P, Sommer T, Dotsch V. The CUE Domain of Cue1 Aligns Growing Ubiquitin Chains with Ubc7 for Rapid Elongation. Mol Cell. 2016 Jun 16;62(6):918-28. doi: 10.1016/j.molcel.2016.04.031. Epub 2016 , Jun 2. PMID:27264873 doi:http://dx.doi.org/10.1016/j.molcel.2016.04.031
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