The isozymes of 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase from Arabidopsis perform differential and overlapping roles in vivo and may be regulated by tyrosine.
Published: 2006
Language: eng
Number of pages: 119
ISBN-13: 9780494211540
Description: 3-deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase catalyzes the first step of the shikimate pathway. Phenotypic analysis of T-DNA insertion lines indicated that the three DAHP synthases perform differential and overlapping roles in vivo. DHS1 may be involved in proper rosette development, DHS2 may be involved in lignin biosynthesis and DHS3 may be required for lignification of the floral stem. Plants deficient in DHS1 are sensitive to tyrosine supplementation, suggesting that the activity of DHS2 and/or DHS3 might be regulated by the aromatic amino acid. Results from an in vitro enzymatic assay and a microarray experiment reveal that neither DHS2 nor DHS3 are inhibited at the protein or transcriptional levels by tyrosine. This suggests that the activity of plant DAHP synthases could be regulated by tyrosine in a novel fashion, possibly by protein-protein interaction.
Notes: Source: Masters Abstracts International, Volume: 45-03, page: 1384.

Thesis (M.Sc.)--University of Toronto, 2006.

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