Sterol carrier protein-2 expression increases NBD-stearate uptake and cytoplasmic diffusion in L cells.
The effects of sterol carrier protein-2 (SCP-2) expression on fatty acid uptake and cytoplasmic diffusion were determined using L cell fibroblasts transfected with cDNA encoding either the 15- or 13. 2-kDa form of SCP-2. Cis-parinarate and 12-N-methyl-(7-nitrobenz-2-oxa-1,3-diazol)aminostearate (NBD-stearate) were used as nonesterifiable fluorescent fatty acid probes. NBD-stearate and cis-parinarate uptake was rapid and saturable. In 15-kDa SCP-2-expressing cells, the extent of NBD-stearate and cis-parinarate uptake was increased 1.4- and 1. 2-fold, respectively, compared with control. In the 13.2-kDa SCP-2-expressing cells, the extent of NBD-stearate and cis-parinarate uptake was increased 1.3- and 1.1-fold, respectively, compared with control cells. NBD-stearate cytoplasmic diffusion was increased 1.5-fold in 15-kDa SCP-2-expressing cells, but not in 13. 2-kDa SCP-2-expressing cells, compared with control cells. After incubation with NBD-stearate for 30 min at 37 degrees C, fluorescence imaging indicated that NBD-stearate was localized primarily in lipid droplets in all cell lines. These results suggest that SCP-2 may be involved not only in fatty acid uptake but also in intracellular fatty acid trafficking.
Murphy
E J
EJ
Department of Physiology and Pharmacology, Texas A & M University, College Station, Texas 77843-4466, USA.
D009327:4-Chloro-7-nitrobenzofurazan / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D000704:Analysis of Variance; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics; D003593:Cytoplasm / Q000378:metabolism; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D007700:Kinetics; D007739:L Cells; D051379:Mice; D008856:Microscopy, Fluorescence; D008970:Molecular Weight; D018996:Myelin P2 Protein / Q000096:biosynthesis / Q000235:genetics; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins / Q000096:biosynthesis; D013228:Stearates / Q000493:pharmacokinetics*; D013261:Sterols / Q000378:metabolism; D014162:Transfection
D002352:Carrier Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005231:Fatty Acids, Unsaturated; D018996:Myelin P2 Protein; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D013228:Stearates; D013261:Sterols; C072087:sterol carrier proteins; C060027:12-N-methyl-7-nitrobenzo-2-oxa-1,3-diazolamino stearate; D009327:4-Chloro-7-nitrobenzofurazan; C013641:parinaric acid