Role of the ubiquitin-selective CDC48(UFD1/NPL4 )chaperone (segregase) in ERAD of OLE1 and other substrates
2002 | journal article
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- Authors
- Braun, Sigurd; Matuschewski, Kai; Rape, Michael; Thoms, Sven ; Jentsch, Stefan
- Abstract
- The OLE pathway of yeast regulates the abundance of the ER-bound enzyme Delta-9 fatty acid desaturase OLE1, thereby controlling unsaturated fatty acid pools and membrane fluidity. Previously, we showed that this pathway is exquisitely regulated by the ubiquitin/proteasome system. Activation of the pathway involves proteasomal processing of a membrane-bound transcription factor and the subsequent mobilization of the cleaved, ubiquitylated transcription factor from its partner molecule by CDC48(UFD1/NPL4), a ubiquitin-selective chaperone-like enzyme. Here we report that the OLE1 protein itself is naturally short-lived and is degraded by ubiquitin/proteasome-dependent ER-associated degradation (ERAD). We found that CDC48(UFD1/NPL4) plays a second role in the OLE pathway by mediating ERAD of OLE1. Intriguingly, other ERAD substrates also require CDC48(UFD1/NPL4) for degradation, indicating that this enzyme is a novel, constitutive component of the ERAD machinery. We propose that CDC48(UFD1/NPL4) functions as a segregase that liberates ubiquitylated proteins from non-modified partners.
- Issue Date
- 2002
- Journal
- The EMBO Journal
- ISSN
- 0261-4189
- Language
- English