Abstract
The yeast integral plasma membrane protein Ist2 belongs to a group of membrane proteins which are synthesized from localized mRNAs. The protein reaches the plasma membrane via the ER on a route operating independently of the classical secretory pathway. We have identified a complex peptide-sorting signal located at the extreme C-terminus. This sorting signal operates independently of targeting information in IST2 mRNA and sorting to the plasma membrane does not require She-mediated mRNA transport into daughter cells. Based on these results, we suggest a posttranslational mechanism, which leads to the concentration of Ist2--via multimerization--at ER sites, followed by direct transport to the plasma membrane. This novel mechanism operates downstream of IST2 mRNA localization.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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COP-Coated Vesicles
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Cell Membrane / metabolism
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Endoplasmic Reticulum / metabolism
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GTPase-Activating Proteins
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism
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Multiprotein Complexes
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Protein Processing, Post-Translational
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Protein Sorting Signals
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Protein Structure, Quaternary
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Protein Transport
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RNA, Fungal / genetics
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RNA, Fungal / metabolism
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RNA, Messenger / genetics
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RNA, Messenger / metabolism
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Recombinant Proteins / genetics
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Recombinant Proteins / metabolism
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Saccharomyces cerevisiae / genetics
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Saccharomyces cerevisiae / metabolism*
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Saccharomyces cerevisiae Proteins / chemistry
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Saccharomyces cerevisiae Proteins / genetics
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Saccharomyces cerevisiae Proteins / metabolism*
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Signal Transduction
Substances
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GTPase-Activating Proteins
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IST2 protein, S cerevisiae
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Multiprotein Complexes
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Protein Sorting Signals
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RNA, Fungal
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RNA, Messenger
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Recombinant Proteins
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SEC23 protein, S cerevisiae
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Saccharomyces cerevisiae Proteins
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Green Fluorescent Proteins