Inducible beta-oxidation pathway in Neurospora crassa.
An inducible beta-oxidation system was demonstrated in a particulate fraction from Neurospora crassa. The activities of all individual beta-oxidation enzymes were enhanced in cells after a shift from a sucrose to an acetate medium. The induction was even more pronounced in transfer to a medium containing oleate as sole carbon and energy source. Since an acyl-coenzyme A (CoA) dehydrogenase was detected instead of acyl-CoA oxidase, the former enzyme seems to catalyze the first step of the beta-oxidation sequence in N. crassa. After isopycnic centrifugation in a linear sucrose gradient, the intracellular organelles housing the fatty acid degradation pathway cosedimented (1.21 g/cm3) with the glyoxylate bypass enzymes isocitrate lyase and malate synthase and were clearly resolved from both mitochondrial marker enzymes (1.19 g/cm3) and catalase (1.26 g/cm3). On the basis of biochemical as well as morphological properties, these particles from N. crassa have recently been designated as glyoxysome-like particles (G. Wanner and T. Theimer, Ann. N.Y. Acad. Sci. 386:269-284, 1982). The failure to detect catalase, urate oxidase, and acyl-CoA oxidase indicate that these glyoxysome-like microbodies in N. crassa lack peroxisomal function and thus are clearly different from the various microbodies reported so far to contain a beta-oxidation pathway.
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D015094:3-Hydroxyacyl CoA Dehydrogenases / Q000378:metabolism; D000102:Acetyl-CoA C-Acyltransferase / Q000378:metabolism; D002499:Centrifugation, Density Gradient; D004746:Enoyl-CoA Hydratase / Q000378:metabolism; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D007522:Isocitrate Lyase / Q000378:metabolism; D009491:Neurospora / Q000201:enzymology*; D009492:Neurospora crassa / Q000201:enzymology* / Q000648:ultrastructure; D019301:Oleic Acid; D009829:Oleic Acids / Q000378:metabolism; D009940:Organoids / Q000201:enzymology; D010084:Oxidation-Reduction
D005227:Fatty Acids; D009829:Oleic Acids; D019301:Oleic Acid; D015094:3-Hydroxyacyl CoA Dehydrogenases; D044943:Fatty Acid Desaturases; D000102:Acetyl-CoA C-Acyltransferase; D007522:Isocitrate Lyase; D004746:Enoyl-CoA Hydratase