Premium
Sec63p and Kar2p are required for the translocation of SRP‐dependent precursors into the yeast endoplasmic reticulum in vivo
Author(s) -
Young Barry P.,
Craven Rachel A.,
Reid Peter J.,
Willer Martin,
Stirling Colin J.
Publication year - 2001
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 - 10.1093/emboj/20.1.262
Subject(s) - endoplasmic reticulum , translocon , biology , signal recognition particle , microbiology and biotechnology , signal recognition particle receptor , chromosomal translocation , secretory pathway , sec61 , secretory protein , signal peptide , protein targeting , secretion , biochemistry , membrane protein , membrane , peptide sequence , gene , golgi apparatus
The translocation of secretory polypeptides into the endoplasmic reticulum (ER) occurs at the translocon, a pore‐forming structure that orchestrates the transport and maturation of polypeptides at the ER membrane. In yeast, targeting of secretory precursors to the translocon can occur by two distinct pathways that are distinguished by their dependence upon the signal recognition particle (SRP). The SRP‐dependent pathway requires SRP and its membrane‐bound receptor, whereas the SRP‐independent pathway requires a separate receptor complex consisting of Sec62p, Sec63p, Sec71p, Sec72p plus lumenal Kar2p/BiP. Here we demonstrate that Sec63p and Kar2p are also required for the SRP‐dependent targeting pathway in vivo . Furthermore, we demonstrate multiple roles for Sec63p, at least one of which is exclusive to the SRP‐independent pathway.