Protein translocation across the thylakoid membrane--a tale of two mechanisms.
In vitro reconstitution assays have been used in recent years to probe the mechanisms by which a variety of cytosolically synthesised proteins are transported across the thylakoid membrane within higher plant chloroplasts. The emerging data suggest that two distinct mechanisms operate. Translocation of a subset of lumenal proteins, namely the 23 kDa and 16 kDa proteins of the oxygen-evolving complex, and of the CFo2 protein (an integral membrane protein), requires only the presence of the thylakoidal delta pH. In contrast, two other lumenal proteins, the 33 kDa oxygen-evolving complex protein and plastocyanin, require also the presence of ATP and at least one stromal factor for efficient transport into isolated thylakoids to take place.
Robinson
C
C
Department of Biological Sciences, University of Warwick, Coventry, UK.
Klösgen
R B
RB
Herrmann
R G
RG
Shackleton
J B
JB
D001692:Biological Transport; D002736:Chloroplasts / Q000648:ultrastructure*; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*
D008565:Membrane Proteins; D010940:Plant Proteins