The Saccharomyces cerevisiae peroxisomal 2,4-dienoyl-CoA reductase is encoded by the oleate-inducible gene SPS19.
beta-Oxidation is compartmentalized in mammals into both mitochondria and peroxisomes. Fatty acids with double bonds at even-numbered positions require for their degradation the auxiliary enzyme 2,4-dienoyl-CoA reductase, and at least three isoforms, two mitochondrial and one peroxisomal, exist in the rat. The Saccharomyces cerevisiae Sps19p is 34% similar to the human and rat mitochondrial reductases, and an SPS19 deleted strain was unable to utilize petroselineate (cis-C18:1(6)) as the sole carbon source, but remained viable on oleate (cis-C18:1(9)). Sps19p was purified to homogeneity from oleate-induced cells and the homodimeric enzyme (native molecular weight 69,000) converted 2,4-hexadienoyl-CoA into 3-hexenoyl-CoA in an NADPH-dependent manner and therefore contained 2,4-dienoyl-CoA reductase activity. Antibodies raised against Sps19p decorated the peroxisomal matrix of oleate-induced cells. SPS19 shares with the sporulation-specific SPS18 a common promoter region that contains an oleate response element. This element unidirectionally regulates transcription of the reductase and is sufficient for oleate induction of a promoterless CYC1-lacZ reporter gene. SPS19 is dispensable for growth and sporulation on solid acetate and oleate media, but is essential for these processes to occur on petroselineate.
Gurvitz
A
A
School of Biochemistry and Molecular Genetics, University of New South Wales, Sydney NSW 2052, Australia.
Rottensteiner
H
H
Kilpeläinen
S H
SH
Hartig
A
A
Hiltunen
J K
JK
Binder
M
M
Dawes
I W
IW
Hamilton
B
B
D000595:Amino Acid Sequence; D000818:Animals; D002451:Cell Compartmentation; D044943:Fatty Acid Desaturases / Q000235:genetics*; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D006801:Humans; D008830:Microbodies / Q000201:enzymology*; D008969:Molecular Sequence Data; D019301:Oleic Acid / Q000494:pharmacology*; D010084:Oxidation-Reduction; D044925:Oxidoreductases Acting on CH-CH Group Donors; D011401:Promoter Regions, Genetic; D051381:Rats; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology* / Q000235:genetics
D019301:Oleic Acid; D044943:Fatty Acid Desaturases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C100153:2,4-dienoyl-CoA reductase