Signal sequences control gating of the protein translocation channel in a substrate-specific manner

Soo Jung Kim, Devarati Mitra, Jeffrey R. Salerno, Ramanujan S. Hegde

Research output: Contribution to journalArticle

89 Scopus citations


N-terminal signal sequences mediate targeting of nascent chains to the endoplasmic reticulum and facilitate opening of the protein translocation channel to the passage of substrate. We have assessed each of these steps for a diverse set of mammalian signals. While minimal differences were seen in their targeting function, signal sequences displayed a remarkable degree of variation in initiating nascent chain access to the lumenal environment. Such substrate-specific properties of signals were evolutionarily conserved, functionally matched to their respective mature domains, and important for the proper biogenesis of some proteins. Thus, the sequence variations of signals do not simply represent functional degeneracy, but instead encode critical differences in translocon gating that are coordinated with their respective passengers to facilitate efficient translocation.

Original languageEnglish (US)
Pages (from-to)207-217
Number of pages11
JournalDevelopmental Cell
Issue number2
StatePublished - Feb 2002


ASJC Scopus subject areas

  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Developmental Biology
  • Cell Biology

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