|
type |
Journal Article |
authors |
Watanabe, M.; Kusano, M.; Oikawa, A.; Fukushima, A.; Noji, M.; Saito, K. |
title |
Physiological roles of beta-substituted alanine synthase gene (Bsas) family in Arabidopsis thaliana |
journal |
Plant Physiol |
Activity |
4.4.1.9 |
Family |
4.4.1.9 |
sel |
unselected |
ui |
lenovcostchi |
year |
(2008) |
volume |
146 |
pages |
310-20 |
| |
keywords |
Arabidopsis/*enzymology/genetics |
abstract |
The beta-substituted alanine synthase (Bsas) family in the large super family of pyridoxal 5'-phosphate-dependent enzymes comprises cysteine (Cys) synthase (CSase) [O-acetylserine (thiol) lyase] and beta-cyanoalanine synthase (CASase) in plants. Nine genomic sequences encode putative Bsas proteins in Arabidopsis thaliana. The physiological roles of these Bsas isoforms in vivo were investigated by the characterization of T-DNA insertion mutants. The analyses of gene expression, activities of CSase and CASase, and levels of Cys and glutathione in the bsas mutants indicated that cytosolic Bsas1;1, plastidic Bsas2;1, and mitochondrial Bsas2;2 play major roles in Cys biosynthesis. Cytosolic Bsas1;1 has the most dominant contribution both in leaf and root, and mitochondrial Bsas2;2 plays a significant role in root. Mitochondrial Bsas3;1 is a genuine CASase. Non-targeted metabolome analyses of knockout mutants were carried out by a combination of gas chromatography time-of-flight mass spectrometry and capillary electrophoresis time-of-flight mass spectrometry. The level of -glutamyl--cyanoalanine decreased in the mutant bsas3;1, indicating the crucial role of Bsas3;1 in -cyanoalanine metabolism in vivo. |
last changed |
2008/04/01 15:48 |
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