Requirements for a conservative protein translocation pathway in chloroplasts.
The chloroplast inner envelope translocon subunit Tic110 is imported via a soluble stromal translocation intermediate. In this study an in-organellar import system is established which allows for an accumulation of this intermediate in order to analyze its requirements for reexport. All results demonstrate that the re-export of Tic110 from the soluble intermediate stage into the inner envelope requires ATP hydrolysis, which cannot be replaced by other NTPs. Furthermore, the molecular chaperone Hsp93 seems prominently involved in the reexport pathway of Tic110, because other stromal intermediates like that of the oxygen evolving complex subunit OE33 (iOE33) en route to the thylakoid lumen interacts preferentially with Hsp70.
Vojta
Lea
L
University of Munich, Botany, Menzinger Str 67, Munich, Germany.
Soll
Jürgen
J
Bölter
Bettina
B
D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006160:Guanosine Triphosphate / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000378:metabolism; D018532:Pisum sativum / Q000378:metabolism / Q000648:ultrastructure; D010940:Plant Proteins / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D015398:Signal Transduction; D020524:Thylakoids / Q000378:metabolism
D026901:Membrane Transport Proteins; D010940:Plant Proteins; D000249:Adenosine Monophosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate