Multiple pathways for the targeting of thylakoid proteins in chloroplasts

Plant Mol Biol. 1998 Sep;38(1-2):209-21.


The assembly of the photosynthetic apparatus requires the import of numerous cytosolically synthesised proteins and their correct targeting into or across the thylakoid membrane. Biochemical and genetic studies have revealed the operation of several targeting pathways for these proteins, some of which are used for thylakoid lumen proteins whereas others are utilised by membrane proteins. Some pathways can be traced back to the prokaryotic ancestors of chloroplasts but at least one pathway appears to have arisen in response to the transfer of genes from the organelle to the nucleus. In this article we review recent findings in this field that point to the operation of a mechanistically unique protein translocase in both plastids and bacteria, and we discuss emerging data that reconcile the remarkable variety of targeting pathways with the natures of the substrate precursor proteins.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Biological Transport
  • Chloroplasts / metabolism*
  • Chloroplasts / physiology
  • Membrane Proteins / metabolism*
  • Membrane Proteins / physiology
  • Molecular Sequence Data
  • Plant Proteins / metabolism*
  • Plant Proteins / physiology
  • Signal Transduction


  • Membrane Proteins
  • Plant Proteins
  • thylakoid polypeptides