spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Massaad, M. J.
Right arrow Articles by Herscovics, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Massaad, M. J.
Right arrow Articles by Herscovics, A.
Journal of Cell Science 114, 4629-4635 (2001)
© 2001 The Company of Biologists Limited

RESEARCH ARTICLE

Interaction of the endoplasmic reticulum {alpha}1,2-mannosidase Mns1p with Rer1p using the split-ubiquitin system

Michel J. Massaad and Annette Herscovics

McGill Cancer Centre, McGill University, Montréal, Québec H3G 1Y6, Canada

Author for correspondence (e-mail: annette{at}med.mcgill.ca)

Accepted September 13, 2001

The {alpha}1,2-mannosidase Mns1p involved in the N-glycosidic pathway in Saccharomyces cerevisiae is a type II membrane protein of the endoplasmic reticulum. The localization of Mns1p depends on retrieval from the Golgi through a mechanism that involves Rer1p. A chimera consisting of the transmembrane domain of Mns1p fused to the catalytic domain of the Golgi {alpha}1,2-mannosyltransferase Kre2p was localized in the endoplasmic reticulum of {Delta}pep4 cells and in the vacuoles of rer1/{Delta}pep4 by indirect immunofluorescence. The split-ubiquitin system was used to determine if there is an interaction between Mns1p and Rer1p in vivo. Co-expression of NubG-Mns1p and Rer1p-Cub-protein A-lexA-VP16 in L40 yeast cells resulted in cleavage of the reporter molecule, protein A-lexA-VP16, detected by western blot analysis and by expression of ß-galactosidase activity. Sec12p, another endoplasmic reticulum protein that depends on Rer1p for its localization, also interacted with Rer1p using the split-ubiquitin assay, whereas the endoplasmic reticulum protein Ost1p showed no interaction. A weak interaction was observed between Alg5p and Rer1p. These results demonstrate that the transmembrane domain of Mns1p is sufficient for Rer1p-dependent endoplasmic reticulum localization and that Mns1p and Rer1p interact. Furthermore, the split-ubiquitin system demonstrates that the C-terminal of Rer1p is in the cytosol.

Key words: Endoplasmic reticulum, Localization, Mannosidase, Retrieval, Protein interaction, Split-ubiquitin






© The Company of Biologists Ltd 2001