Efficient secretion of small proteins in mammalian cells relies on Sec62-dependent posttranslational translocation.

ABSTRACT: Mammalian cells secrete a large number of small proteins, but their mode of translocation into the endoplasmic reticulum is not fully understood. Cotranslational translocation was expected to be inefficient due to the small time window for signal sequence recognition by the signal recognition particle (SRP). Impairing the SRP pathway and reducing cellular levels of the translocon component Sec62 by RNA interference, we found an alternate, Sec62-dependent translocation path in mammalian cells required for the efficient translocation of small proteins with N-terminal signal sequences. The Sec62-dependent translocation occurs posttranslationally via the Sec61 translocon and requires ATP. We classified preproteins into three groups: 1) those that comprise ≤100 amino acids are strongly dependen

SUBMITTER: Lakkaraju AK 

PROVIDER: S-EPMC3395660 | biostudies-literature | 2012 Jul

REPOSITORIES: biostudies-literature