A general mechanism for regulation of access to the translocon: Competition for a membrane attachment site on ribosomes Journal Article

   


Authors: Möller, I.; Jung, M.; Beatrix, B.; Levy, R.; Kreibich, G.; Zimmermann, R.; Wiedmann, M.; Lauring, B.
Article Title: A general mechanism for regulation of access to the translocon: Competition for a membrane attachment site on ribosomes
Abstract: For proteins to enter the secretory pathway, the membrane attachment site (M-site) on ribosomes must bind cotranslationally to the Sec61 complex present in the endoplasmic reticulum membrane. The signal recognition particle (SRP) and its receptor (SR) are required for targeting, and the nascent polypeptide associated complex (NAC) prevents inappropriate targeting of nonsecretory nascent chains. In the absence of NAC, any ribosome, regardless of the polypeptide being synthesized, binds to the endoplasmic reticulum membrane, and even nonsecretory proteins are translocated across the endoplasmic reticulum membrane. By occupying the M-site, NAC prevents all ribosome binding unless a signal peptide and SRP are present. The mechanism by which SRP overcomes the NAC block is unknown. We show that signal peptide- bound SRP occupies the M-site and therefore keeps it free of NAC. To expose the M-site and permit ribosome binding, SR can pull SRP away from the M-site without prior release of SRP from the signal peptide.
Keywords: signal transduction; nonhuman; protein localization; animal cell; animals; protein targeting; membrane proteins; endoplasmic reticulum; signal peptide; protein transport; protein biosynthesis; binding site; trans-activators; cytosol; membrane binding; ribosomes; binding, competitive; ribosome; cross linking; molecular chaperones; docking protein; secretory protein; signal recognition particle; priority journal; article
Journal Title: Proceedings of the National Academy of Sciences of the United States of America
Volume: 95
Issue: 23
ISSN: 0027-8424
Publisher: National Academy of Sciences  
Date Published: 1998-11-10
Start Page: 13425
End Page: 13430
Language: English
DOI: 10.1073/pnas.95.23.13425
PUBMED: 9811816
PROVIDER: scopus
PMCID: PMC24835
DOI/URL:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032506006&doi=10.1073%2fpnas.95.23.13425&partnerID=40&md5=790d45374d79d0feb1f34b46a1b81139
Notes: Article -- Export Date: 12 December 2016 -- Source: Scopus
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MSK Authors
  1. Martin Wiedmann
    44 Wiedmann
  2. Birgitta M Beatrix
    4 Beatrix
  3. Ines Moeller
    4 Moeller
  4. Brett P Lauring
    2 Lauring
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