3-Deoxy-D-arabino-heptulosonate 7-phosphate (DAHP) synthase (DHS) catalyzes the first step of the shikimate pathway - a pathway involved in Tyrosine (Tyr), Tryptophan (Trp) and Phenylalanine (Phe) biosynthesis - by condensation of phosphoenolpyruvate and erythrose-4-phosphate to DAHP. Our lab previously demonstrated that Arabidopsis thaliana shikimate pathway flux is regulated by Tyr and Trp.
This project suggests that A. thaliana DHS1 overexpressor lines have increased Trp accumulation with Tyr treatment, and that an A. thaliana DHS2 overexpressor line treated with Tyr has unchanged Trp accumulation, indicating that AtDHS2 is Tyr-sensitive. Confocal microscopy of all 3 AtDHS isoforms fused to yellow fluorescent protein demonstrates chloroplast localization. Bimolecular fluorescence complementation indicates that protein-protein interactions occur in the cytoplasm, and not in the chloroplast, for AtDHS1 and AtDHS2 with the metabolic regulator At14-3-3ω. These findings suggest that protein-protein interactions could regulate accumulation of AtDHS2 in the chloroplast, and are perhaps modulated by Tyr.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/43563 |
| Date | 09 January 2014 |
| Creators | Johnson, Daniel |
| Contributors | Christendat, Dinesh |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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