Evidence for a hepatocyte membrane fatty acid transport protein using rat liver mRNA expression in Xenopus laevis oocytes.
The aim of the present study was to directly demonstrate that hepatocellular uptake of long-chain fatty acids represents a non-diffusional uptake mechanism. Xenopus laevis oocytes were used for expression of rat liver mRNA to identify the liver fatty acid uptake system. Injection of total rat liver poly(A)+ RNA into oocytes resulted in a dose-dependent increase in fatty acid uptake. The most active mRNA was found in the 1.1-2.1 kb subfraction. In contrast, expression of the liver cytosolic fatty acid binding protein (L-FABP) or the previously suggested candidate carrier protein, mitochondrial aspartate aminotransferase (mGOT), did not induce fatty acid uptake. It is concluded that in rat liver, fatty acid transport represents a protein-mediated transport system.
Fitscher
B A
BA
Department of Medicine IV, University Hospital of Heidelberg, Germany.
Klaassen-Schlüter
C M
CM
Stremmel
W
W
D000818:Animals; D001219:Aspartate Aminotransferases / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D005591:Chemical Fractionation; D003600:Cytosol / Q000737:chemistry; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D018014:Gene Transfer Techniques; D008099:Liver / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D008930:Mitochondria, Liver / Q000201:enzymology; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D009865:Oocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D014982:Xenopus laevis
D002352:Carrier Proteins; C493320:Fabp1 protein, mouse; C493321:Fabp1 protein, rat; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009829:Oleic Acids; D012333:RNA, Messenger; D019301:Oleic Acid; D001219:Aspartate Aminotransferases