Dominant negative suppression of arabidopsis photoresponses by mutant phytochrome A sequences identifies spatially discrete regulatory domains in the photoreceptor
| Autor: | Nancy Douglas, Margaret T. Boylan, Peter H. Quail |
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| Rok vydání: | 1994 |
| Předmět: |
Light
DNA Mutational Analysis Mutant Arabidopsis Plant Science Models Biological Hypocotyl Structure-Activity Relationship Phytochrome A Transduction (genetics) Chromoprotein Sequence Deletion chemistry.chemical_classification Genetics biology Phytochrome Biliverdine Cell Biology Plants Genetically Modified biology.organism_classification Amino acid Cell biology chemistry Spectrophotometry Edible Grain Research Article |
| Zdroj: | The Plant Cell. 6:449-460 |
| ISSN: | 1532-298X 1040-4651 |
| DOI: | 10.1105/tpc.6.3.449 |
| Popis: | We used the exaggerated short hypocotyl phenotype induced by oat phytochrome A overexpression in transgenic Arabidopsis to monitor the biological activity of mutant phytochrome A derivatives. Three different mutations, which were generated by removing 52 amino acids from the N terminus (delta N52), the entire C-terminal domain (delta C617), or amino acids 617-686 (delta 617-686) of the oat molecule, each caused striking dominant negative interference with the ability of endogenous Arabidopsis phytochrome A to inhibit hypocotyl growth in continuous far-red light ("far-red high irradiance response" conditions). By contrast, in continuous white or red light, delta N52 was as active as the unmutagenized oat phytochrome A protein in suppressing hypocotyl elongation, while delta C617 and delta 617-686 continued to exhibit dominant negative behavior under these conditions. These data suggest that at least three spatially discrete molecular domains coordinate the photoregulatory activities of phytochrome A in Arabidopsis seedlings. The first is the chromophore-bearing N-terminal domain between residues 53 and 616 that is apparently sufficient for the light-induced initiation but not the completion of productive interactions with transduction chain components. The second is the C-terminal domain between residues 617 and 1129 that is apparently necessary for completion of productive interactions under all irradiation conditions. The third is the N-terminal 52 amino acids that are apparently necessary for completion of productive interactions only under far-red high irradiance conditions and are completely dispensable under white and red light regimes. |
| Databáze: | OpenAIRE |
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