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Multiple determinants direct the orientation of signal-anchor proteins : the topogenic role of the hydrophobic signal domain

Wahlberg, J. M. and Spiess, M.. (1997) Multiple determinants direct the orientation of signal-anchor proteins : the topogenic role of the hydrophobic signal domain. The Journal of cell biology, Vol. 137, H. 3. pp. 555-562.

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Official URL: http://edoc.unibas.ch/dok/A5258067

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Abstract

The orientation of signal-anchor proteins in the endoplasmic reticulum membrane is largely determined by the charged residues flanking the apolar, membrane-spanning domain and is influenced by the folding properties of the NH2-terminal sequence. However, these features are not generally sufficient to ensure a unique topology. The topogenic role of the hydrophobic signal domain was studied in vivo by expressing mutants of the asialoglycoprotein receptor subunit H1 in COS-7 cells. By replacing the 19-residue transmembrane segment of wild-type and mutant H1 by stretches of 7-25 leucine residues, we found that the length and hydrophobicity of the apolar sequence significantly affected protein orientation. Translocation of the NH2 terminus was favored by long, hydrophobic sequences and translocation of the COOH terminus by short ones. The topogenic contributions of the transmembrane domain, the flanking charges, and a hydrophilic NH2-terminal portion were additive. In combination these determinants were sufficient to achieve unique membrane insertion in either orientation.
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:Rockefeller University Press
ISSN:0021-9525
Note:Publication type according to Uni Basel Research Database: Journal article
Language:English
Identification Number:
Last Modified:31 Dec 2015 10:42
Deposited On:22 Mar 2012 13:19

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