ATP-dependent redistribution of phosphatidylethanolamine in the plasma membrane of an epithelial and a hepatocytic cell line.
The redistribution of spin-labeled phospholipid analogues of sphingomyelin (SM) and phosphatidylethanolamine (PE) from the outer to the inner leaflet of the plasma membrane of an epithelial (CaCo-2) and a hepatocytic cell line (HepG2) was investigated. The amount of analogues in the outer leaflet was determined by their back-exchange to bovine serum albumin (BSA). For both cell lines a fast ATP-dependent inward movement of spinlabeled PE (SL-PE) was found while SL-SM redistributed only slowly by a passive mechanism. After depletion of intracellular ATP transverse diffusion of SL-PE was similar to that of SL-SM. The data are compatible with the presence of an aminophospholipid translocase in both cell lines.
Pomorski
T
T
Institut für Biology und Biophysik Mathematisch-Naturwissenschaftliche Fakultät L. Humboldt-Universität zu Berlin, Germany.
Burger
K
K
Müller
P
P
Porwoll
S
S
Tauber
R
R
Herrmann
A
A
D000255:Adenosine Triphosphate / Q000502:physiology*; D018938:Caco-2 Cells; D002460:Cell Line / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004847:Epithelial Cells; D004848:Epithelium / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D010714:Phosphatidylethanolamines / Q000378:metabolism*; D013109:Sphingomyelins / Q000378:metabolism; D013113:Spin Labels
D010714:Phosphatidylethanolamines; D013109:Sphingomyelins; D013113:Spin Labels; D000255:Adenosine Triphosphate