| First Author | Chen B | Year | 2006 |
| Journal | Proc Natl Acad Sci U S A | Volume | 103 |
| Issue | 2 | Pages | 341-6 |
| PubMed ID | 16407162 | Mgi Jnum | J:248285 |
| Mgi Id | MGI:6093391 | Doi | 10.1073/pnas.0506618103 |
| Citation | Chen B, et al. (2006) The activity of a human endoplasmic reticulum-associated degradation E3, gp78, requires its Cue domain, RING finger, and an E2-binding site. Proc Natl Acad Sci U S A 103(2):341-6 |
| abstractText | Efficient targeting of proteins for degradation from the secretory pathway is essential to homeostasis. This occurs through endoplasmic reticulum (ER)-associated degradation (ERAD). In this study, we establish that a human ubiquitin ligase (E3), gp78, and a specific E2, Ube2g2, are both critically important for ERAD of multiple substrates. gp78 exhibits a complex domain structure that, in addition to the RING finger, includes a ubiquitin-binding Cue domain and a specific binding site for Ube2g2. Disruption of either of these domains abolishes gp78-mediated ubiquitylation and protein degradation, resulting in accumulation of substrates in their fully glycosylated forms in the ER. This suggests that gp78-mediated ubiquitylation is an early step in ERAD that precedes dislocation of substrates from the ER. The in vivo requirement for both an E2-binding site distinct from the RING finger and a ubiquitin-binding domain intrinsic to an E3 suggests a previously unappreciated level of complexity in ubiquitin ligase function. These results also provide proof of principle that interrupting a specific E2-E3 interaction can selectively inhibit ERAD. |
