A constitutively monomeric UVR8 photoreceptor confers enhanced UV-B photomorphogenesis
| Autor: | Roman Podolec, Kelvin Lau, Roman Ulm, Timothée B. Wagnon, Michael Hothorn |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Photoreceptors
Plant 0106 biological sciences UVR8 abiotic stress Chromosomal Proteins Non-Histone Ultraviolet Rays Ubiquitin-Protein Ligases Arabidopsis Plant Biology acclimation perception medicine.disease_cause 01 natural sciences Serine 03 medical and health sciences Gene Expression Regulation Plant Gene expression medicine Allele gene 030304 developmental biology 0303 health sciences Mutation in-vivo function Multidisciplinary biology Arabidopsis Proteins Chemistry transformation Biological Sciences photoreceptor Cell biology Ubiquitin ligase stress acclimation ddc:580 interacts cop1 uv-b biology.protein Photomorphogenesis Signal transduction transcription protein signal transduction hy5 010606 plant biology & botany |
| Zdroj: | Proceedings of the National Academy of Sciences, Vol. 118, No 6 (2021) P. e2017284118 Proceedings of the National Academy of Sciences of the United States of America |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Significance Coping with UV-B is crucial for plant survival in sunlight. The UV-B photoreceptor UVR8 regulates gene expression associated with photomorphogenesis, acclimation, and UV-B stress tolerance. UV-B photon reception by UVR8 homodimers results in monomerization, followed by interaction with the key signaling protein COP1. We have discovered a UV-B hypersensitive UVR8 photoreceptor that confers strongly enhanced UV-B tolerance and generated a UVR8 variant based on the underlying mutation that shows extremely enhanced constitutive signaling activity. Our findings provide key mechanistic insight into how plants respond and acclimate to UV-B radiation. The plant ultraviolet-B (UV-B) photoreceptor UVR8 plays an important role in UV-B acclimation and survival. UV-B absorption by homodimeric UVR8 induces its monomerization and interaction with the E3 ubiquitin ligase COP1, leading ultimately to gene expression changes. UVR8 is inactivated through redimerization, facilitated by RUP1 and RUP2. Here, we describe a semidominant, hyperactive allele, namely uvr8-17D, that harbors a glycine-101 to serine mutation. UVR8G101S overexpression led to weak constitutive photomorphogenesis and extreme UV-B responsiveness. UVR8G101S was observed to be predominantly monomeric in vivo and, once activated by UV-B, was not efficiently inactivated. Analysis of a UVR8 crystal structure containing the G101S mutation revealed the distortion of a loop region normally involved in stabilization of the UVR8 homodimer. Plants expressing a UVR8 variant combining G101S with the previously described W285A mutation exhibited robust constitutive photomorphogenesis. This work provides further insight into UVR8 activation and inactivation mechanisms and describes a genetic tool for the manipulation of photomorphogenic responses. |
| Databáze: | OpenAIRE |
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