Transport of activated fatty acids by the peroxisomal ATP-binding-cassette transporter Pxa2 in a semi-intact yeast cell system

Eur J Biochem. 1997 Nov 1;249(3):657-61. doi: 10.1111/j.1432-1033.1997.00657.x.

Abstract

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.

MeSH terms

  • ATP-Binding Cassette Transporters / metabolism*
  • Acyl Coenzyme A / metabolism*
  • Adenosine Triphosphate / metabolism
  • Adrenoleukodystrophy / etiology
  • Biological Transport
  • Cell Membrane Permeability
  • Digitonin / pharmacology
  • Fatty Acids / metabolism*
  • Fungal Proteins / metabolism
  • Humans
  • Microbodies / metabolism*
  • Oxidation-Reduction
  • Protoplasts / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins*

Substances

  • ATP-Binding Cassette Transporters
  • Acyl Coenzyme A
  • Fatty Acids
  • Fungal Proteins
  • PXA2 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Adenosine Triphosphate
  • Digitonin