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The hydrophobic core of the Sec61 translocon defines the hydrophobicity threshold for membrane integration

Junne, T. and Kocik, L. and Spiess, M.. (2010) The hydrophobic core of the Sec61 translocon defines the hydrophobicity threshold for membrane integration. Molecular Biology of the Cell, 21 (10). pp. 1662-1670.

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Official URL: http://edoc.unibas.ch/dok/A5842477

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Abstract

The Sec61 translocon mediates the translocation of proteins across the endoplasmic reticulum membrane and the lateral integration of transmembrane segments into the lipid bilayer. The structure of the idle translocon is closed by a lumenal plug domain and a hydrophobic constriction ring. To test the function of the apolar constriction, we have mutated all six ring residues of yeast Sec61p to more hydrophilic, bulky, or even charged amino acids (alanines, glycines, serines, tryptophans, lysines, or aspartates). The translocon was found to be surprisingly tolerant even to the charge mutations in the constriction ring, because growth and translocation efficiency were not drastically affected. Most interestingly, ring mutants were found to affect the integration of hydrophobic sequences into the lipid bilayer, indicating that the translocon does not simply catalyze the partitioning of potential transmembrane segments between an aqueous environment and the lipid bilayer but that it also plays an active role in setting the hydrophobicity threshold for membrane integration.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Growth & Development > Biochemistry (Spiess)
UniBasel Contributors:Spiess, Martin
Item Type:Article, refereed
Article Subtype:Research Article
Bibsysno:Link to catalogue
Publisher:American Society for Cell Biology
ISSN:1059-1524
e-ISSN:1939-4586
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:08 Nov 2017 11:02
Deposited On:14 Sep 2012 06:38

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