Transport of activated fatty acids by the peroxisomal ATP-binding-cassette transporter Pxa2 in a semi-intact yeast cell system.
In the yeast Saccharomyces cerevisiae, fatty acid beta-oxidation is restricted to peroxisomes. Previous studies have shown two possible routes by which fatty acids enter the peroxisome. The first route involves transport of medium-chain fatty acids across the peroxisomal membrane as free fatty acids, followed by activation within the peroxisome by Faa2p, an acyl-CoA synthetase. The second route involves transport of long-chain fatty acids. Long-chain fatty acids enter the peroxisome via a route that involves activation in the extraperoxisomal space, followed by transport across the peroxisomal membrane. It has been suggested that this transport is dependent upon the peroxisomal ATP-binding-cassette transporters Pxa1p and Pxa2p. In this paper we investigated whether Pxa2p is directly responsible for the transport of C18:1-CoA, a long-chain acyl-CoA ester. Using protoplasts in which the plasma membrane has been selectively permeabilised by digitonin, we show that C18:1-CoA, but not C8:0-CoA, enters the peroxisome via Pxa2p, in an ATP-dependent fashion. The results obtained may contribute to the elucidation of the primary defect in the human disease X-linked adrenoleukodystrophy.
Verleur
N
N
Department of Clinical Chemistry, University of Amsterdam, Academic Medical Centre, The Netherlands.
Hettema
E H
EH
van Roermund
C W
CW
Tabak
H F
HF
Wanders
R J
RJ
D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000214:Acyl Coenzyme A / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism; D000326:Adrenoleukodystrophy / Q000209:etiology; D001692:Biological Transport; D002463:Cell Membrane Permeability; D004072:Digitonin / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D006801:Humans; D008830:Microbodies / Q000378:metabolism*; D010084:Oxidation-Reduction; D011523:Protoplasts / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins
D018528:ATP-Binding Cassette Transporters; D000214:Acyl Coenzyme A; D005227:Fatty Acids; D005656:Fungal Proteins; C103561:PXA2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000255:Adenosine Triphosphate; D004072:Digitonin