Oleate beta-oxidation in yeast involves thioesterase but not Yor180c protein that is not a dienoyl-CoA isomerase.
The beta-oxidation of oleic acid in Saccharomyces cerevisiae (S. cerevisiae) was studied by comparing the growth of wild-type cells on oleic acid or palmitic acid with the growth of mutants that either had a deletion in the YOR180c (DCI1) gene reported to encode delta3,5,delta2,4-dienoyl-CoA isomerase (dienoyl-CoA isomerase) or in the PTE1 gene encoding peroxisomal thioesterase 1. Growth of wild-type cells was indistinguishable from that of YOR180c mutant cells on either palmitic acid or oleic acid, whereas the PTE1 mutant grew slower and to a lower density on oleic acid but not on palmitic acid. The identification of 3,5-tetradecadienoic acid in the medium of wild-type cells but not in the medium of the PTE1 mutant proves the operation of the thioesterase-dependent pathway of oleate beta-oxidation in S. cerevisiae. Dienoyl-CoA isomerase activity was very low in wild-type cells, fourfold higher in the YOR180c mutant, and not associated with purified Yor180c protein. These observations support the conclusion that the YOR180c gene does not encode dienoyl-CoA isomerase.
Ntamack
André G
AG
Department of Chemistry, City College and Graduate School of the City University of New York, New York, NY 10031, USA.
Karpichev
Igor V
IV
Gould
Stephen J
SJ
Small
Gillian M
GM
Schulz
Horst
H
D019748:Carbon-Carbon Double Bond Isomerases / Q000235:genetics / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D019301:Oleic Acid / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D020675:Peroxisomes / Q000201:enzymology; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D013053:Spectrophotometry; D013379:Substrate Specificity; D013869:Thiolester Hydrolases / Q000378:metabolism*; D014170:Transformation, Genetic
D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; D019301:Oleic Acid; D013869:Thiolester Hydrolases; D019748:Carbon-Carbon Double Bond Isomerases; C120150:DCI1 protein, S cerevisiae; C085575:delta(3,5),delta(2,4)-dienoyl-CoA isomerase