Early Scanning of Nascent Polypeptides inside the Ribosomal Tunnel by NAC.
ER targeting
NAC
RAC
SRP
Sec61
chaperone
nascent chain
nascent polypeptide-associated complex
protein biogenesis
ribosome
Journal
Molecular cell
ISSN: 1097-4164
Titre abrégé: Mol Cell
Pays: United States
ID NLM: 9802571
Informations de publication
Date de publication:
05 09 2019
05 09 2019
Historique:
received:
01
02
2019
revised:
08
05
2019
accepted:
19
06
2019
pubmed:
5
8
2019
medline:
30
1
2020
entrez:
5
8
2019
Statut:
ppublish
Résumé
Cotranslational processing of newly synthesized proteins is fundamental for correct protein maturation. Protein biogenesis factors are thought to bind nascent polypeptides not before they exit the ribosomal tunnel. Here, we identify a nascent chain recognition mechanism deep inside the ribosomal tunnel by an essential eukaryotic cytosolic chaperone. The nascent polypeptide-associated complex (NAC) inserts the N-terminal tail of its β subunit (N-βNAC) into the ribosomal tunnel to sense substrates directly upon synthesis close to the peptidyl-transferase center. N-βNAC escorts the growing polypeptide to the cytosol and relocates to an alternate binding site on the ribosomal surface. Using C. elegans as an in vivo model, we demonstrate that the tunnel-probing activity of NAC is essential for organismal viability and critical to regulate endoplasmic reticulum (ER) protein transport by controlling ribosome-Sec61 translocon interactions. Thus, eukaryotic protein maturation relies on the early sampling of nascent chains inside the ribosomal tunnel.
Identifiants
pubmed: 31377116
pii: S1097-2765(19)30487-3
doi: 10.1016/j.molcel.2019.06.030
pii:
doi:
Substances chimiques
Caenorhabditis elegans Proteins
0
SEC Translocation Channels
0
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
996-1006.e8Informations de copyright
Copyright © 2019 Elsevier Inc. All rights reserved.