De novo synthesis and desaturation of fatty acids at the mitochondrial acyl-carrier protein, a subunit of NADH:ubiquinone oxidoreductase in Neurospora crassa

Abstract

We have cultivated the cel mutant of Neurospora crassa defective in cytosolic fatty acid synthesis with [2- 14C]malonate and found radioactivity covalently attached to the mitochondrial acyl-carrier protein (ACP), a subunit of the respiratory chain NADH:ubiquinone oxidoreductase. We purified the ACP by reverse-phase HPLC: the bound acyl groups were trans-esterified to methylesters and analyzed by gas chromatography. The saturated C 0 to C 18 fatty acids and oleic acid were detected. De novo synthesis and desaturation of fatty acids at the ACP subunit of NADH:ubiquinone oxidoreductase and use of the products of this mitnchondrial synthetic pathway for cardiolipin synthesis is discussed.