Topogenic signals in integral membrane proteins

Eur J Biochem. 1988 Jul 1;174(4):671-8. doi: 10.1111/j.1432-1033.1988.tb14150.x.


Integral membrane proteins are characterized by long apolar segments that cross the lipid bilayer. Polar domains flanking these apolar segments have a more balanced amino acid composition, typical for soluble proteins. We show that the apolar segments from three different kinds of membrane-assembly signals do not differ significantly in amino acid content, but that the inside/outside location of the polar domains correlates strongly with their content of arginyl and lysyl residues, not only for bacterial inner-membrane proteins, but also for eukaryotic.proteins from the endoplasmic reticulum, the plasma membrane, the inner mitochondrial membrane, and the chloroplast thylakoid membrane. A positive-inside rule thus seems to apply universally to all integral membrane proteins, with apolar regions targeting for membrane integration and charged residues providing the topological information.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / analysis*
  • Arginine / analysis
  • Eukaryotic Cells / analysis
  • Lipid Bilayers
  • Lysine / analysis
  • Membrane Proteins / analysis*
  • Prokaryotic Cells / analysis


  • Amino Acids
  • Lipid Bilayers
  • Membrane Proteins
  • Arginine
  • Lysine