Regulation of C1 Metabolism in Arabidopsis: The N-terminal Regulatory Domain of Cystathionine {gamma} Synthase Is Cleaved in Response to Folate Starvation

Autor: Loizeau, Karen, Gambonnet, Bernadette, Zhang, Guo-Fang, Curien, Gilles, Jabrin, Samuel, van Der Straeten, Dominique, Lambert, Willy E, Rébeillé, Fabrice, Ravanel, Stéphane
Přispěvatelé: Laboratoire de physiologie cellulaire végétale (LPCV), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Laboratory of Toxicology, State University of Ghent, Unit of Plant Hormone Signalling and Bioimaging, Department of Molecular Genetics, Ghent University [Belgium] (UGENT), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Universiteit Gent = Ghent University [Belgium] (UGENT), Université Joseph Fourier - Grenoble 1 (UJF)-Institut National de la Recherche Agronomique (INRA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Universiteit Gent = Ghent University (UGENT)
Jazyk: angličtina
Rok vydání: 2007
Předmět:
Zdroj: Plant Physiology
Plant Physiology, American Society of Plant Biologists, 2007, 145, pp.491-503. ⟨10.1104/pp.107.105379⟩
Plant Physiology, 2007, 145, pp.491-503. ⟨10.1104/pp.107.105379⟩
ISSN: 0032-0889
1532-2548
Popis: In all organisms, control of folate homeostasis is of vital importance to sustain the demand for one carbon (C1) units that are essential in major metabolic pathways. In this study we induced folate deficiency in Arabidopsis cells by using two antifolate inhibitors. This treatment triggered a rapid and important decrease in the pool of folates with significant modification in the distribution of C1-substituted folate coenzymes, suggesting an adaptive response to favor a preferential shuttling of the flux of C1-units to the synthesis of nucleotides over the synthesis of methionine (Met). Metabolic profiling of folate-deficient cells indicated important perturbation of the activated methyl cycle because of the impairment of Met synthases that are deprived of their substrate 5-methyl-tetrahydrofolate. Intriguingly, S-adenosylmethionine (AdoMet) and Met pools declined during the initial period of folate starvation but were further restored to typical levels. Re-establishment of Met and AdoMet homeostasis was concomitant with a previously unknown post-translational regulation that consists in the removal of 92 amino acids at the N-terminus of cystathionine gamma-synthase (CGS), the first specific enzyme for Met synthesis. Rescue experiments and analysis of different stresses indicated that CGS processing is specifically associated with perturbation of the folates pool. Also, CGS processing involves chloroplastic serine-type proteases that are expressed in various plant species subjected to folate starvation. We suggest that a metabolic effector, to date unidentified, can modulate CGS activity in vivo through an interaction with the N-terminal domain of the enzyme and that removal of this domain can suppress this regulation.
Databáze: OpenAIRE
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