Determination of the Transmembrane Topology of Yeast Sec61p, an Essential Component of the Endoplasmic Reticulum Translocation Complex

Barrie M Wilkinson, Angela J Critchley, Colin J Stirling

Research output: Contribution to journalArticle

122 Citations (Scopus)

Abstract

Sec61p is a highly conserved integral membrane protein that plays a role in the formation of a protein-conducting channel required for the translocation of polypeptides into, and across, the membrane of the endoplasmic reticulum. As a major step toward elucidating the structure of the endoplasmic reticulum translocation apparatus, we have determined the transmembrane topology of Sec61p using a combination of C-terminal reporter-domain fusions and the in situ digestion of specifically inserted factor Xa protease cleavage sites. Our data indicate the presence of 10 transmembrane domains, including several with surprisingly limited hydrophobicity. Furthermore, we provide evidence for complex intramolecular interactions in which these weakly hydrophobic domains require C-terminal sequences for their correct topogenesis. The incorporation of sequences with limited hydrophobicity into the bilayer may play a vital role in the formation of an aqueous membrane channel required for the translocation of hydrophilic polypeptide chains.
Original languageEnglish
Pages (from-to)25590-25597
Number of pages8
JournalJournal of Biological Chemistry
Volume271
Issue number41
DOIs
Publication statusPublished - 1997

Fingerprint Dive into the research topics of 'Determination of the Transmembrane Topology of Yeast Sec61p, an Essential Component of the Endoplasmic Reticulum Translocation Complex'. Together they form a unique fingerprint.

  • Cite this