An Arabidopsis mutant disrupted in valine catabolism is also compromised in peroxisomal fatty acid β‐oxidation
- 6 July 2004
- journal article
- Published by Wiley in FEBS Letters
- Vol. 571 (1-3) , 147-153
- https://doi.org/10.1016/j.febslet.2004.06.071
Abstract
Characterisation of the Arabidopsis dbr5 mutant, which was isolated on the basis of 2,4-dichlorophenoxybutyric acid (2,4-DB) resistance, revealed that it is disrupted in the CHY1 gene. CHY1 encodes a peroxisomal protein that is 43% identical to the mammalian β-hydroxyisobutryl-CoA hydrolase of valine catabolism. We show that 2,4-DB resistance and the associated sucrose dependent seedling growth are due to a large activity decrease of 3-ketoacyl-CoA thiolase, which is involved in peroxisomal fatty acid β-oxidation. 14C-feeding studies demonstrate that dbr5 and chy1 seedlings are reduced in valine catabolism. These data support the hypothesis that CHY1 plays a key role in peroxisomal valine catabolism and that disruption of this enzyme results in accumulation of a toxic intermediate, methacrylyl-CoA, that inhibits 3-ketoacyl-CoA thiolase activity and thus blocks peroxisomal β-oxidation. We also show that CHY1 is repressed in seedlings grown on sugars, which suggests that branched chain amino acid catabolism is transcriptionally regulated by nutritional statusKeywords
This publication has 43 references indexed in Scilit:
- The Mitochondrial Isovaleryl-Coenzyme A Dehydrogenase of Arabidopsis Oxidizes Intermediates of Leucine and Valine CatabolismPlant Physiology, 2001
- Arabidopsis thaliana mutants disrupted in lipid mobilizationBiochemical Society Transactions, 2000
- Multiple Signaling Pathways in Gene Expression during Sugar Starvation. Pharmacological Analysis of din Gene Expression in Suspension-Cultured Cells of ArabidopsisPlant Physiology, 2000
- Molecular and genetic mechanisms regulating the transition from embryo development to germinationTrends in Plant Science, 1999
- Identification, Separation, and Characterization of Acyl-Coenzyme A Dehydrogenases Involved in Mitochondrial β-Oxidation in Higher Plants1Plant Physiology, 1999
- Purification, and phosphorylation in vivo and in vitro, of phosphoenolpyruvate carboxykinase from cucumber cotyledonsFEBS Letters, 1995
- Oxidative Decarboxylation of Branched-Chain 2-Oxo Fatty Acids by Higher Plant PeroxisomesPlant Physiology, 1988
- Identification of subsidiary catalytic groups at the active site of β-ketoacyl-CoA thiolase by covalent modification of the proteinBiochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology, 1986
- Gluconeogenesis from Amino Acids in Germinating Castor Bean Endosperm and its Role in Transport to the EmbryoPlant Physiology, 1967
- A Revised Medium for Rapid Growth and Bio Assays with Tobacco Tissue CulturesPhysiologia Plantarum, 1962