Premium
Signal recognition particle mediates post‐translational targeting in eukaryotes
Author(s) -
Abell Benjamin M,
Pool Martin R,
Schlenker Oliver,
Sinning Irmgard,
High Stephen
Publication year - 2004
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7600281
Subject(s) - biology , signal recognition particle , computational biology , posttranslational modification , microbiology and biotechnology , genetics , peptide sequence , signal peptide , gene , biochemistry , enzyme
Signal recognition particle (SRP) plays a central role in the delivery of classical secretory and membrane proteins to the endoplasmic reticulum (ER). All nascent chains studied to date dissociate from SRP once released from the ribosome, thereby supporting a strictly cotranslational mode of action for eukaryotic SRP. We now report a novel post‐translational function for SRP in the targeting of tail‐anchored (TA) proteins to the ER. TA proteins possess a hydrophobic membrane insertion sequence at their C‐terminus such that it can only emerge from the ribosome after translation is terminated. We show that SRP can associate post‐translationally with this type of ER‐targeting signal, and deliver newly synthesised TA proteins to the ER membrane by a pathway dependent upon GTP and the SRP receptor. We find that dependency upon this SRP‐dependent route is precursor specific, and propose a unifying model to describe the biogenesis of TA proteins in vivo .