Chaperone-Mediated Sec61 Channel Gating during ER Import of Small Precursor Proteins Overcomes Sec61 Inhibitor-Reinforced Energy Barrier.

ABSTRACT: Protein transport into the mammalian endoplasmic reticulum (ER) is mediated by the heterotrimeric Sec61 channel. The signal recognition particle (SRP) and TRC systems and Sec62 have all been characterized as membrane-targeting components for small presecretory proteins, whereas Sec63 and the lumenal chaperone BiP act as auxiliary translocation components. Here, we report the transport requirements of two natural, small presecretory proteins and engineered variants using semipermeabilized human cells after the depletion of specific ER components. Our results suggest that hSnd2, Sec62, and SRP and TRC receptor each provide alternative targeting pathways for short secretory proteins and define rules of engagement for the actions of Sec63 and BiP during their membrane translocation. We find th

SUBMITTER: Haßdenteufel S 

PROVIDER: S-EPMC5946456 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature