Subcellular localization of plastoquinone and ubiquinone synthesis in spinach cells.
In vivo labeling of spinach etiolated leaves with [(3)H]mevalonate followed by rapid cell fractionation procedure showed that ER-Golgi membranes are involved in transport of plastoquinone (PQ) and ubiquinone (UQ) to plastids and mitochondria, respectively. Translocation of these lipids was inhibited by agents which affect protein and lipid intracellular transport causing structural and functional disintegration of the ER-Golgi system (monensin, brefeldin) and interfere with mitochondrial energy conservation (carbonyl cyanide m-chlorophenylhydrazone), but was not affected by colchicine which influences the organization of the cytoskeletal network. Colchicine treatment resulted in marked stimulation of PQ and UQ synthesis. Results of experiments with pre-exposure of etiolated seedlings to light suggest that translocation processes are dependent on the plastid developmental state and their capacity as acceptors of PQ. Thus, the experiments indicate that biosynthesis and transport of PQ and UQ involve multiple cellular compartments and that kinetics of the transport process is dependent on the actual physiological conditions.
Wanke
M
M
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, 02-106, Warsaw, Poland.
Dallner
G
G
Swiezewska
E
E
D001693:Biological Transport, Active / Q000187:drug effects; D020126:Brefeldin A / Q000494:pharmacology; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism; D007700:Kinetics; D008928:Mitochondria / Q000378:metabolism; D008985:Monensin / Q000494:pharmacology; D018087:Plastids / Q000378:metabolism; D010971:Plastoquinone / Q000378:metabolism*; D018724:Spinacia oleracea / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D014451:Ubiquinone / Q000378:metabolism*
D014451:Ubiquinone; D020126:Brefeldin A; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D008985:Monensin; D010971:Plastoquinone