| Structural highlights
Function
[UB2G2_HUMAN] Accepts ubiquitin from the E1 complex and catalyzes its covalent attachment to other proteins. In vitro catalyzes 'Lys-48'-linked polyubiquitination. Involved in endoplasmic reticulum-associated degradation (ERAD).[1] [2] [AMFR_HUMAN] E3 ubiquitin-protein ligase that mediates the polyubiquitination of a number of proteins such as CD3D, CYP3A4, CFTR and APOB for proteasomal degradation. Component of a VCP/p97-AMFR/gp78 complex that participates in the final step of endoplasmic reticulum-associated degradation (ERAD). The VCP/p97-AMFR/gp78 complex is involved in the sterol-accelerated ERAD degradation of HMGCR through binding to the HMGCR-INSIG complex at the ER membrane and initiating ubiquitination of HMGCR. The ubiquitinated HMGCR is then released from the ER by the complex into the cytosol for subsequent destruction. Also acts as a scaffold protein to assemble a complex that couples ubiquitination, retranslocation and deglycosylation. Mediates tumor invasion and metastasis as a receptor for the GPI/autocrine motility factor.[3] [4] [5] [6]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The activity of RING finger ubiquitin ligases (E3) is dependent on their ability to facilitate transfer of ubiquitin from ubiquitin-conjugating enzymes (E2) to substrates. The G2BR domain within the E3 gp78 binds selectively and with high affinity to the E2 Ube2g2. Through structural and functional analyses, we determine that this occurs on a region of Ube2g2 distinct from binding sites for ubiquitin-activating enzyme (E1) and RING fingers. Binding to the G2BR results in conformational changes in Ube2g2 that affect ubiquitin loading. The Ube2g2:G2BR interaction also causes an approximately 50-fold increase in affinity between the E2 and RING finger. This results in markedly increased ubiquitylation by Ube2g2 and the gp78 RING finger. The significance of this G2BR effect is underscored by enhanced ubiquitylation observed when Ube2g2 is paired with other RING finger E3s. These findings uncover a mechanism whereby allosteric effects on an E2 enhance E2-RING finger interactions and, consequently, ubiquitylation.
Allosteric activation of E2-RING finger-mediated ubiquitylation by a structurally defined specific E2-binding region of gp78.,Das R, Mariano J, Tsai YC, Kalathur RC, Kostova Z, Li J, Tarasov SG, McFeeters RL, Altieri AS, Ji X, Byrd RA, Weissman AM Mol Cell. 2009 Jun 26;34(6):674-85. PMID:19560420[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ David Y, Ziv T, Admon A, Navon A. The E2 ubiquitin conjugating enzymes direct polyubiquitination to preferred lysines. J Biol Chem. 2010 Jan 8. PMID:20061386 doi:M109.089003
- ↑ Sato T, Sako Y, Sho M, Momohara M, Suico MA, Shuto T, Nishitoh H, Okiyoneda T, Kokame K, Kaneko M, Taura M, Miyata M, Chosa K, Koga T, Morino-Koga S, Wada I, Kai H. STT3B-dependent posttranslational N-glycosylation as a surveillance system for secretory protein. Mol Cell. 2012 Jul 13;47(1):99-110. doi: 10.1016/j.molcel.2012.04.015. Epub 2012 , May 17. PMID:22607976 doi:10.1016/j.molcel.2012.04.015
- ↑ Shimizu K, Tani M, Watanabe H, Nagamachi Y, Niinaka Y, Shiroishi T, Ohwada S, Raz A, Yokota J. The autocrine motility factor receptor gene encodes a novel type of seven transmembrane protein. FEBS Lett. 1999 Aug 6;456(2):295-300. PMID:10456327
- ↑ Fang S, Ferrone M, Yang C, Jensen JP, Tiwari S, Weissman AM. The tumor autocrine motility factor receptor, gp78, is a ubiquitin protein ligase implicated in degradation from the endoplasmic reticulum. Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14422-7. Epub 2001 Nov 27. PMID:11724934 doi:10.1073/pnas.251401598
- ↑ Song BL, Sever N, DeBose-Boyd RA. Gp78, a membrane-anchored ubiquitin ligase, associates with Insig-1 and couples sterol-regulated ubiquitination to degradation of HMG CoA reductase. Mol Cell. 2005 Sep 16;19(6):829-40. PMID:16168377 doi:10.1016/j.molcel.2005.08.009
- ↑ Pabarcus MK, Hoe N, Sadeghi S, Patterson C, Wiertz E, Correia MA. CYP3A4 ubiquitination by gp78 (the tumor autocrine motility factor receptor, AMFR) and CHIP E3 ligases. Arch Biochem Biophys. 2009 Mar 1;483(1):66-74. doi: 10.1016/j.abb.2008.12.001., Epub 2008 Dec 10. PMID:19103148 doi:10.1016/j.abb.2008.12.001
- ↑ Das R, Mariano J, Tsai YC, Kalathur RC, Kostova Z, Li J, Tarasov SG, McFeeters RL, Altieri AS, Ji X, Byrd RA, Weissman AM. Allosteric activation of E2-RING finger-mediated ubiquitylation by a structurally defined specific E2-binding region of gp78. Mol Cell. 2009 Jun 26;34(6):674-85. PMID:19560420 doi:10.1016/j.molcel.2009.05.010
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