1. BiP/GRP78 mediates ERAD targeting of proteins produced by membrane-bound ribosomes stalled at the STOP-codon
- Author
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Linda Sasset, Michael P. Myers, Oscar R. Burrone, Gianluca Petris, Francesca Cesaratto, and Angela Re
- Subjects
Proteasome Endopeptidase Complex ,Proline ,Ubiquitin-Protein Ligases ,Endoplasmic-reticulum-associated protein degradation ,Protein degradation ,Endoplasmic Reticulum ,Ribosome ,Cell Line ,03 medical and health sciences ,0302 clinical medicine ,Structural Biology ,Endopeptidases ,Animals ,Humans ,Amino Acid Sequence ,Molecular Biology ,Endoplasmic Reticulum Chaperone BiP ,Heat-Shock Proteins ,030304 developmental biology ,chemistry.chemical_classification ,Adenosine Triphosphatases ,Mammals ,0303 health sciences ,biology ,Ubiquitin ,Endoplasmic reticulum ,Nuclear Proteins ,Endoplasmic Reticulum-Associated Degradation ,bioinformatics ,Stop codon ,Cell biology ,Ubiquitin ligase ,Amino acid ,HEK293 Cells ,Proteasome ,chemistry ,Protein Biosynthesis ,Proteolysis ,biology.protein ,Codon, Terminator ,Peptides ,Ribosomes ,030217 neurology & neurosurgery ,Molecular Chaperones - Abstract
Translational stalling of ribosome bound to endoplasmic reticulum (ER) membrane requires an accurate clearance of the associated polypeptides, which is not completely understood in mammals. We characterized in mammalian cells the model of ribosomal stalling at the STOP-codon based on proteins tagged at the C-terminus with the picornavirus 2A peptide followed by a termination codon instead of the Proline (2A*). We exploited the 2A* stalling model to characterize the pathway of degradation of ER-targeted polypeptides. We report that the ER chaperone BiP/GRP78 is a new main factor involved. Moreover, degradation of the ER-stalled polypeptides required the activities of the AAA-ATPase VCP/p97, its associated deubiquitinylase YOD1, the ribosome-associated ubiquitin ligase Listerin and the proteasome. In human proteome, we found two human C-terminal amino acid sequences that cause similar stalling at the STOP-codon. Our data suggest that translational stalling at the ER membrane activates protein degradation at the interface of ribosomal- and ER-associated quality control systems.
- Published
- 2019