Preferential targeting of a signal recognition particle-dependent precursor to the Ssh1p translocon in yeast

Michael P. Spiller, Colin J. Stirling

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Protein translocation across the endoplasmic reticulum membrane occurs via a "translocon" channel formed by the Sec61p complex. In yeast, two channels exist: the canonical Sec61p channel and a homolog called Ssh1p. Here, we used trapped translocation intermediates to demonstrate that a specific signal recognition particle-dependent substrate, Sec71p, is targeted exclusively to Ssh1p. Strikingly, we found that, in the absence of Ssh1p, precursor could be successfully redirected to canonical Sec61p, demonstrating that the normal targeting reaction must involve preferential sorting to Ssh1p. Our data therefore demonstrate that Ssh1p is the primary translocon for Sec71p and reveal a novel sorting mechanism at the level of the endoplasmic reticulum membrane enabling precursors to be directed to distinct translocons. Interestingly, the Ssh1p-dependent translocation of Sec71p was found to be dependent upon Sec63p, demonstrating a previously unappreciated functional interaction between Sec63p and the Ssh1p translocon.
Original languageEnglish
Pages (from-to)21953-21960
Number of pages8
JournalJournal of Biological Chemistry
Volume286
Issue number25
DOIs
Publication statusPublished - 2011

Fingerprint Dive into the research topics of 'Preferential targeting of a signal recognition particle-dependent precursor to the Ssh1p translocon in yeast'. Together they form a unique fingerprint.

  • Cite this