Signal sequences: more than just greasy peptides

Trends Cell Biol. 1998 Oct;8(10):410-5. doi: 10.1016/s0962-8924(98)01360-9.


Export signal sequences target newly synthesized proteins to the endoplasmic reticulum of eukaryotic cells and the plasma membrane of bacteria. All signal sequences contain a hydrophobic core region, but, despite this, they show great variation in both overall length and amino acid sequence. Recently, it has become clear that this variation allows signal sequences to specify different modes of targeting and membrane insertion and even to perform functions after being cleaved from the parent protein. This review argues that signal sequences are not simply greasy peptides but sophisticated, multipurpose peptides containing a wealth of functional information.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation
  • Bacterial Proteins / metabolism
  • Biological Transport
  • Cell Membrane / metabolism
  • Cytosol / metabolism
  • Endoplasmic Reticulum / metabolism
  • Escherichia coli / metabolism
  • Histocompatibility Antigens Class I / immunology
  • Mammals / metabolism
  • Membrane Proteins*
  • Molecular Sequence Data
  • Protein Sorting Signals / chemistry
  • Protein Sorting Signals / physiology*
  • Proteins / metabolism
  • Serine Endopeptidases / metabolism
  • Structure-Activity Relationship


  • Bacterial Proteins
  • Histocompatibility Antigens Class I
  • Membrane Proteins
  • Protein Sorting Signals
  • Proteins
  • Serine Endopeptidases
  • type I signal peptidase