Evidence for an ER to Golgi to chloroplast protein transport pathway.
Chloroplast protein import is generally believed to occur posttranslationally through the interaction of a precursor protein with the Toc and Tic transport apparatus in the plastid envelope membranes. The cleavable N-terminal transit peptide present on translocated proteins has been considered to be essential and sufficient for targeting. This idea was recently challenged when an analysis of the chloroplast proteome revealed many proteins without a predicted transit peptide. A recent study demonstrates the existence of a novel chloroplast targeting pathway, starting with protein entry into the endoplasmic reticulum and involving the Golgi apparatus.
Radhamony
Resmi N
RN
Section of Plant Biology, University of California-Davis, Davis, CA 95616, USA.
Theg
Steven M
SM
D017360:Arabidopsis; D029681:Arabidopsis Proteins / Q000502:physiology; D002736:Chloroplasts / Q000378:metabolism* / Q000648:ultrastructure; D006056:Golgi Apparatus / Q000378:metabolism* / Q000648:ultrastructure; D008565:Membrane Proteins / Q000502:physiology; D026901:Membrane Transport Proteins / Q000502:physiology; D008954:Models, Biological; D010940:Plant Proteins / Q000502:physiology; D011498:Protein Precursors / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*
D029681:Arabidopsis Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010940:Plant Proteins; D011498:Protein Precursors; C491244:TOC75 protein, Arabidopsis; C457764:Tic20 protein, Arabidopsis; C112475:Toc34 protein, plant