The UVR8 UV-B Photoreceptor: Perception, Signaling and Response.
The UVR8 UV-B Photoreceptor: Perception, Signaling and Response.
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DOI：
10.1199/tab.0164
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发表时间：
2013-01-01
期刊：
影响因子：
--
通讯作者：
Ulm, Roman
中科院分区：
文献类型：
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作者：
Tilbrook, Kimberley;Arongaus, Adriana B;Ulm, Roman
紫外线-B辐射(UV-B)是阳光的固有部分，伴随着显著的生物效应。植物能够通过UV-B光感受器UVR8感知UV-B，UVR8与特定的分子信号通路相连，导致UV-B驯化。在这里，我们综述了植物的生物学过程，从最初的UV-B感知和信号转导到已知的促进在阳光下存活的UV-B反应。UVR8 UV-B光感受器以同源二聚体的形式存在，它通过特定的内在色氨酸作为UV-B生色团，在UV-B吸收时立即单体。UVR8单体与E3泛素连接酶COP1相互作用，启动了导致基因表达变化的分子信号通路。这种信号输出导致UVR8依赖的反应，包括UV-B诱导的光形态发生和UV-B吸收的黄酮醇的积累。该途径的负反馈调节由WD40-重复蛋白RUP1和RUP2提供，它们促进UVR8的二聚，破坏UVR8-COP1的相互作用。尽管近年来该领域取得了快速进展，但UVR8 UV-B信号的更多组件不断出现，这些组件与已建立的UVR8、COP1、RUP1、RUP2和HY5信号的确切相互作用需要定义。UVR8 UV-B信号代表了我们对植物如何能够感知其光环境并相应地调整其生长的进一步了解。
Ultraviolet-B radiation (UV-B) is an intrinsic part of sunlight that is accompanied by significant biological effects. Plants are able to perceive UV-B using the UV-B photoreceptor UVR8 which is linked to a specific molecular signaling pathway and leads to UV-B acclimation. Herein we review the biological process in plants from initial UV-B perception and signal transduction through to the known UV-B responses that promote survival in sunlight. The UVR8 UV-B photoreceptor exists as a homodimer that instantly monomerises upon UV-B absorption via specific intrinsic tryptophans which act as UV-B chromophores. The UVR8 monomer interacts with COP1, an E3 ubiquitin ligase, initiating a molecular signaling pathway that leads to gene expression changes. This signaling output leads to UVR8-dependent responses including UV-B-induced photomorphogenesis and the accumulation of UV-B-absorbing flavonols. Negative feedback regulation of the pathway is provided by the WD40-repeat proteins RUP1 and RUP2, which facilitate UVR8 redimerization, disrupting the UVR8-COP1 interaction. Despite rapid advancements in the field of recent years, further components of UVR8 UV-B signaling are constantly emerging, and the precise interplay of these and the established players UVR8, COP1, RUP1, RUP2 and HY5 needs to be defined. UVR8 UV-B signaling represents our further understanding of how plants are able to sense their light environment and adjust their growth accordingly.