The phosphatidylcholine-transfer protein catalyzed import of phosphatidylcholine into isolated rat liver mitochondria.
In order to study the individual steps involved in the import of phosphatidylcholine (PC) into rat liver mitochondria, a number of PC analogues were introduced into the outer membrane of isolated mitochondria. Two fluorescent PC species, i.e. 1-palmitoyl-2-(16-bimanylthio)hexadecanoyl-PC (bimane-PC) and 1-palmitoyl-2-(10-pyrene)decanoyl-PC (pyrene-PC), and one radiolabeled PC species, i.e. 1-palmitoyl-2-[1-14C]oleoyl-PC (14C-POPC), were studied. The PC analogues were introduced from small unilamellar vesicles with the use of PC-specific transfer protein. The amount of PC imported was quantified by reisolation of the mitochondria. Import of the fluorescent PC species was monitored by on-line fluorescence spectroscopy. The distribution of the newly inserted PC between the outer and the inner membrane was assessed by separation of the two membranes using digitonin treatment. All analogues tested remained exclusively localized in the outer membrane thereby suggesting that additional (extramitochondrial) factors are required to initiate transfer of PC to the inner membrane.
Nicolay
K
K
Institute of Molecular Biology and Medical Biotechnology, University of Utrecht, The Netherlands.
Hovius
R
R
Bron
R
R
Wirtz
K
K
de Kruijff
B
B
D000727:Androgen-Binding Protein; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D005453:Fluorescence; D066298:In Vitro Techniques; D008297:Male; D008930:Mitochondria, Liver / Q000378:metabolism* / Q000648:ultrastructure; D010713:Phosphatidylcholines / Q000378:metabolism*; D049294:Phospholipid Transfer Proteins; D060789:Prostatein; D051381:Rats; D011919:Rats, Inbred Strains; D060765:Secretoglobins; D014598:Uteroglobin; D060788:Mammaglobin B
D000727:Androgen-Binding Protein; D002352:Carrier Proteins; D010713:Phosphatidylcholines; D049294:Phospholipid Transfer Proteins; D060789:Prostatein; D060765:Secretoglobins; D014598:Uteroglobin; C511484:Scgb1d2 protein, rat; C511483:Scgb1d4 protein, rat; C021248:1-palmitoyl-2-pyrenedecanoylphosphatidylcholine; C556468:Scgb2a1 protein, rat; D060788:Mammaglobin B