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The reversible reaction catalyzed by serine hydroxymethyltransferase (SHMT) is the major one-carbon unit source for essential metabolic processes. The Arabidopsis thaliana genome encodes seven SHMT isozymes localized in mitochondria, plastids, nuclei, and the cytosol. Knowledge of the biochemical
Folates are important cofactors in one-carbon metabolism in all living organisms. Since only plants and micro- organisms are capable of biosynthesizing folates, humans depend entirely on their diet as a folate source. Given the low folate content of several staple crop products, folate deficiency
Roots have both indeterminate and determinate developmental programs. The latter is preceded by the former. It is not well understood how the indeterminacy-to-determinacy switch (IDS) is regulated. We isolated a moots koom2 (mko2; 'short root' in Mayan) Arabidopsis thaliana mutant with determinate
We identified a mutation in Arabidopsis that resulted in defective embryos, and we designated this mutation globular arrest1 (gla1). The predicted amino acid sequence encoded by the GLA1 gene is homologous to the amino acid sequences of folylpolyglutamate synthetase (FPGS) and dihydrofolate
Cryptochromes are almost ubiquitous blue-light receptors and act in several species as central components of the circadian clock. Despite being evolutionary and structurally related with DNA photolyases, a class of light-driven DNA-repair enzymes, and having similar cofactor compositions,
Cytosolic HPPK/DHPS (cytHPPK/DHPS) in Arabidopsis is a functional enzyme with activity similar to its mitochondrial isoform. Genomic complementation of the cytHPPK/DHPS knockout mutant with the wild type gene led to a complete rescue of the stress sensitive mutant phenotype in seed germination tests
As sessile organisms growing in an ever-changing environment, plants must integrate multiple regulatory inputs to promote the appropriate developmental responses. One such nutritional signal is cellular sugar levels, which rise and fall throughout the day and affect a variety of developmental
The Synechocystis Slr0642 protein and its plastidial Arabidopsis (Arabidopsis thaliana) ortholog At2g32040 belong to the folate-biopterin transporter (FBT) family within the major facilitator superfamily. Both proteins transport folates when expressed in Escherichia coli. Because the structural
DNA methylation is a critical, dynamically regulated epigenetic mark. Small chemicals can be valuable tools in probing cellular processes, but the set of chemicals with broad effects on epigenetic regulation is very limited. Using the Arabidopsis thaliana repressor of silencing1 mutant, in which
Folates in vivo undergo oxidative cleavage, giving pterin and p-aminobenzoylglutamate (pABAGlu) moieties. These breakdown products are excreted in animals, but their fate is unclear in microorganisms and unknown in plants. As indirect evidence from this and previous studies strongly suggests that
The vacuoles of pea (Pisum sativum) leaves and red beet (Beta vulgaris) storage root are major sites for the intracellular compartmentation of folates. In the light of these findings and preliminary experiments indicating that some plant multidrug resistance-associated protein (MRP) subfamily
A rapid, sensitive and reproducible method for analysis of naturally-occurring folates and folic acid in food has been developed and validated. A single-enzyme extraction step, in which a pure recombinant enzyme of plant origin (Arabidopsis thaliana) was used, enabled fast and reproducible
A round robin comparison was performed in order to test the performance of a recently developed LC-MS/MS method for quantification of 6 folate forms. Eighty-nine samples representing the food groups of fruits, vegetables, legumes, cereals, dairy products, meat, and offal were analyzed by two
Tetrahydropterin-dependent aromatic amino acid hydroxylases (AAHs) are known from animals and microbes but not plants. A survey of genomes and ESTs revealed AAH-like sequences in gymnosperms, mosses, and algae. Analysis of full-length AAH cDNAs from Pinus taeda, Physcomitrella patens, and
Multidrug resistance protein AtMRPs belong to the ATP binding cassette (ABC) transporter super family. ABC proteins are membrane proteins involved in the transport of a broad range of amphipathic organic anions across membranes. MRPs (ABCCs) are one of the highly represented subfamilies of ABC