Arabidopsis SAMT1 Defines a Plastid Transporter Regulating Plastid Biogenesis and Plant Development
| Autor: | Andreas P.M. Weber, Bilal Camara, Florence Bouvier, Nicole Linka, Jérôme Mutterer, Jean-Charles Isner |
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| Rok vydání: | 2006 |
| Předmět: |
DNA
Bacterial 0106 biological sciences S-Adenosylmethionine Anion Transport Proteins Molecular Sequence Data Mutant Arabidopsis Nicotiana benthamiana Plant Science Biology 01 natural sciences Plant Viruses Substrate Specificity 03 medical and health sciences Tobacco Arabidopsis thaliana Gene Silencing Plastids Plastid Research Articles 030304 developmental biology 2. Zero hunger 0303 health sciences Arabidopsis Proteins Gene Expression Profiling Protoplasts fungi Membrane Transport Proteins food and beverages Pigments Biological Cell Biology Plants Genetically Modified biology.organism_classification Lipids S-Adenosylhomocysteine Recombinant Proteins Protein Transport Cytosol Phenotype Biochemistry Mutation Transmethylation Biogenesis 010606 plant biology & botany |
| Zdroj: | The Plant Cell. 18:3088-3105 |
| ISSN: | 1532-298X |
| DOI: | 10.1105/tpc.105.040741 |
| Popis: | S-Adenosylmethionine (SAM) is formed exclusively in the cytosol but plays a major role in plastids; SAM can either act as a methyl donor for the biogenesis of small molecules such as prenyllipids and macromolecules or as a regulator of the synthesis of aspartate-derived amino acids. Because the biosynthesis of SAM is restricted to the cytosol, plastids require a SAM importer. However, this transporter has not yet been identified. Here, we report the molecular and functional characterization of an Arabidopsis thaliana gene designated SAM TRANSPORTER1 (SAMT1), which encodes a plastid metabolite transporter required for the import of SAM from the cytosol. Recombinant SAMT1 produced in yeast cells, when reconstituted into liposomes, mediated the counter-exchange of SAM with SAM and with S-adenosylhomocysteine, the by-product and inhibitor of transmethylation reactions using SAM. Insertional mutation in SAMT1 and virus-induced gene silencing of SAMT1 in Nicotiana benthamiana caused severe growth retardation in mutant plants. Impaired function of SAMT1 led to decreased accumulation of prenyllipids and mainly affected the chlorophyll pathway. Biochemical analysis suggests that the latter effect represents one prominent example of the multiple events triggered by undermethylation, when there is decreased SAM flux into plastids. |
| Databáze: | OpenAIRE |
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