title: The mitochondrial sulfur dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 is required for amino acid catabolism during carbohydrate starvation and embryo development in Arabidopsis.
abstract: The sulfur dioxygenase ETHYLMALONIC ENCEPHALOPATHY PROTEIN1 (ETHE1) catalyzes the oxidation of persulfides in the mitochondrial matrix and is essential for early embryo development in Arabidopsis (Arabidopsis thaliana). We investigated the biochemical and physiological functions of ETHE1 in plant metabolism using recombinant Arabidopsis ETHE1 and three transfer DNA insertion lines with 50% to 99% decreased sulfur dioxygenase activity. Our results identified a new mitochondrial pathway catalyzing the detoxification of reduced sulfur species derived from cysteine catabolism by oxidation to thiosulfate. Knockdown of the sulfur dioxygenase impaired embryo development and produced phenotypes of starvation-induced chlorosis during short-day growth conditions and extended darkness, indicating that ETHE1 has a key function in situations of high protein turnover, such as seed production and the use of amino acids as alternative respiratory substrates during carbohydrate starvation. The amino acid profile of mutant plants was similar to that caused by defects in the electron-transfer flavoprotein/electron-transfer flavoprotein:ubiquinone oxidoreductase complex and associated dehydrogenases. Thus, in addition to sulfur amino acid catabolism, ETHE1 also affects the oxidation of branched-chain amino acids and lysine.
authors.affiliation: Institute for Plant Genetics, Leibniz University Hannover, 30419 Hannover, Germany.
authors.forename: Lena
authors.initials: L
authors.lastname: Krüßel
authors.forename: Johannes
authors.initials: J
authors.lastname: Junemann
authors.forename: Markus
authors.initials: M
authors.lastname: Wirtz
authors.forename: Hannah
authors.initials: H
authors.lastname: Birke
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Thornton
authors.forename: Luke W
authors.initials: LW
authors.lastname: Browning
authors.forename: Gernot
authors.initials: G
authors.lastname: Poschet
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Hell
authors.forename: Janneke
authors.initials: J
authors.lastname: Balk
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Braun
authors.forename: Tatjana M
authors.initials: TM
authors.lastname: Hildebrandt
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D017360:Arabidopsis / Q000196:embryology* / Q000201:enzymology* / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D004269:DNA, Bacterial / Q000235:genetics; D049308:Dioxygenases / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D005978:Glutathione / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D008928:Mitochondria / Q000201:enzymology*; D008954:Models, Biological; D016254:Mutagenesis, Insertional / Q000235:genetics; D010084:Oxidation-Reduction; D010641:Phenotype; D012639:Seeds / Q000196:embryology* / Q000201:enzymology; D013379:Substrate Specificity; D013440:Sulfides / Q000378:metabolism; D013447:Sulfites / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D004269:DNA, Bacterial; D013440:Sulfides; D013447:Sulfites; C036483:T-DNA; D013455:Sulfur; D049308:Dioxygenases; C000593849:ETHE1 protein, Arabidopsis; C477654:sulfur dioxygenase; D005978:Glutathione