Up-regulation of the peroxisomal beta-oxidation system occurs in butyrate-grown Candida tropicalis following disruption of the gene encoding peroxisomal 3-ketoacyl-CoA thiolase.
In the yeast Candida tropicalis, two thiolase isozymes, peroxisomal acetoacetyl-CoA thiolase and peroxisomal 3-ketoacyl-CoA thiolase, participate in the peroxisomal fatty acid beta-oxidation system. Their individual contributions have been demonstrated in cells grown on butyrate, with C. tropicalis able to grow in the absence of either one. In the present study, a lack of peroxisomal 3-ketoacyl-CoA thiolase protein resulted in increased expression (up-regulation) of acetoacetyl-CoA thiolase and other peroxisomal proteins, whereas a lack of peroxisomal acetoacetyl-CoA thiolase produced no corresponding effect. Overexpression of the acetoacetyl-CoA thiolase gene did not suppress the up-regulation or the growth retardation on butyrate in cells without peroxisomal 3-ketoacyl-CoA thiolase, even though large amounts of the overexpressed acetoacetyl-CoA thiolase were detected in most of the peroxisomes of butyrate-grown cells. These results provide important evidence of the greater contribution of 3-ketoacyl-CoA thiolase to the peroxisomal beta-oxidation system than acetoacetyl-CoA thiolase in C. tropicalis and a novel insight into the regulation of the peroxisomal beta-oxidation system.
Ueda
Mitsuyoshi
M
Laboratory of Applied Biological Chemistry, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Yoshida, Sakyo-ku, Kyoto 606-8501, Japan. miueda@sbchem.kyoto-u.ac.jp
Kanayama
Naoki
N
Kamasawa
Naomi
N
Osumi
Masako
M
Tanaka
Atsuo
A
D000101:Acetyl-CoA C-Acetyltransferase / Q000096:biosynthesis / Q000235:genetics; D000102:Acetyl-CoA C-Acyltransferase / Q000172:deficiency* / Q000235:genetics; D015152:Blotting, Northern; D015153:Blotting, Western; D002087:Butyrates; D041022:Candida tropicalis / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D005227:Fatty Acids / Q000378:metabolism; D005656:Fungal Proteins / Q000096:biosynthesis; D016253:Microscopy, Immunoelectron; D020675:Peroxisomes / Q000201:enzymology / Q000378:metabolism*; D015854:Up-Regulation
D002087:Butyrates; D005227:Fatty Acids; D005656:Fungal Proteins; D000102:Acetyl-CoA C-Acyltransferase; D000101:Acetyl-CoA C-Acetyltransferase