



Other version: https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18468
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Mechanisms of UV-B light-induced photoreceptor UVR8 nuclear localization dynamics |
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Published in | New phytologist. 2022, vol. 236, no. 5, p. 1824-1837 | |
Abstract | Light regulates the subcellular localization of plant photoreceptors, a key step in light signaling. Ultraviolet-B radiation (UV-B) induces the plant photoreceptor UV RESISTANCE LOCUS 8 (UVR8) nuclear accumulation, where it regulates photomorphogenesis. However, the molecular mechanism for the UV-B-regulated UVR8 nuclear localization dynamics is unknown. With fluorescence recovery after photobleaching (FRAP), cell fractionation followed by immunoblotting and co-immunoprecipitation (Co-IP) assays we tested the function of UVR8-interacting proteins including CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1), REPRESSOR OF UV-B PHOTOMORPHOGENESIS 1 (RUP1) and RUP2 in the regulation of UVR8 nuclear dynamics in Arabidopsis thaliana. We showed that UV-B-induced rapid UVR8 nuclear translocation is independent of COP1, which previously was shown to be required for UV-B-induced UVR8 nuclear accumulation. Instead, we provide evidence that the UV-B-induced UVR8 homodimer-to-monomer photo-switch and the concurrent size reduction of UVR8 enables its monomer nuclear translocation, most likely via free diffusion. Nuclear COP1 interacts with UV-B-activated UVR8 monomer, thereby promoting UVR8 nuclear retention. Conversely, RUP1and RUP2, whose expressions are induced by UV-B, inhibit UVR8 nuclear retention via attenuating the UVR8-COP1 interaction, allowing UVR8 to exit the nucleus. Collectively, our data suggest that UV-B-induced monomerization of UVR8 promotes its nuclear translocation via free diffusion. In the nucleus, COP1 binding promotes UVR8 monomer nuclear retention, which is counterbalanced by the major negative regulators RUP1 and RUP2. | |
Keywords | Arabidopsis — UV RESISTANCE LOCUS 8 — Nuclear import — Photomorphogenesis — Photoreceptor — Tomato — Arabidopsis Proteins / metabolism — Chromosomal Proteins, Non-Histone / metabolism — Signal Transduction — Arabidopsis / metabolism — Photoreceptors, Plant / metabolism — Ultraviolet Rays — Ubiquitin-Protein Ligases / metabolism — Gene Expression Regulation, Plant | |
Identifiers | DOI: 10.1111/nph.18468 PMID: 36089828 | |
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![]() ![]() ![]() ![]() Other version: https://nph.onlinelibrary.wiley.com/doi/10.1111/nph.18468 |
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Research group | Groupe Ulm | |
Projects | National Natural Science Foundation of China: 31870261 National Natural Science Foundation of China: 32070261 National Natural Science Foundation of China: 32170246 the Medicine and Engineering interdisciplinary Research Fund of SJTU: YG2021ZD07 China Postdoctoral Science Foundation: 2021M692072 National Key Research and Development Program of China: 2018YFD1000800 Natural Science Foundation of Shanghai: 22ZR1431300 Swiss National Science Foundation: 31003A_175774 | |
Citation (ISO format) | FANG, Fang et al. Mechanisms of UV-B light-induced photoreceptor UVR8 nuclear localization dynamics. In: New phytologist, 2022, vol. 236, n° 5, p. 1824-1837. doi: 10.1111/nph.18468 https://archive-ouverte.unige.ch/unige:164989 |