6vk0

Structural highlights

Function

USA1_YEAST Scaffold protein of the endoplasmic reticulum-associated degradation (ERAD) (also known as endoplasmic reticulum quality control, ERQC) pathway involved in ubiquitin-dependent degradation of misfolded endoplasmic reticulum proteins. Component of 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 multiple functions in ERAD including recruitment of DER1 to the HRD1 ubiquitin ligase, and regulation of HRD1 activity. Involved in oligomerization of HRD1, which is required for ERAD-L, and in HRD1 autoubiquitination and degradation.^{[1] [2] [3] [4] [5]}

References

1. ↑ Carvalho P, Goder V, Rapoport TA. Distinct ubiquitin-ligase complexes define convergent pathways for the degradation of ER proteins. Cell. 2006 Jul 28;126(2):361-73. PMID:16873066 doi:10.1016/j.cell.2006.05.043
2. ↑ Kim I, Li Y, Muniz P, Rao H. Usa1 protein facilitates substrate ubiquitylation through two separate domains. PLoS One. 2009 Oct 29;4(10):e7604. doi: 10.1371/journal.pone.0007604. PMID:19898607 doi:http://dx.doi.org/10.1371/journal.pone.0007604
3. ↑ Carroll SM, Hampton RY. Usa1p is required for optimal function and regulation of the Hrd1p endoplasmic reticulum-associated degradation ubiquitin ligase. J Biol Chem. 2010 Feb 19;285(8):5146-56. doi: 10.1074/jbc.M109.067876. Epub 2009 , Nov 24. PMID:19940128 doi:http://dx.doi.org/10.1074/jbc.M109.067876
4. ↑ Horn SC, Hanna J, Hirsch C, Volkwein C, Schutz A, Heinemann U, Sommer T, Jarosch E. Usa1 functions as a scaffold of the HRD-ubiquitin ligase. Mol Cell. 2009 Dec 11;36(5):782-93. doi: 10.1016/j.molcel.2009.10.015. PMID:20005842 doi:http://dx.doi.org/10.1016/j.molcel.2009.10.015
5. ↑ Carvalho P, Stanley AM, Rapoport TA. Retrotranslocation of a misfolded luminal ER protein by the ubiquitin-ligase Hrd1p. Cell. 2010 Nov 12;143(4):579-91. doi: 10.1016/j.cell.2010.10.028. PMID:21074049 doi:http://dx.doi.org/10.1016/j.cell.2010.10.028