Arabidopsis STO/BBX24 negatively regulates UV-B signaling by interacting with COP1 and repressing HY5 transcriptional activity
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香港中文大學研究人員

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摘要UV-B (280-315 nm) is an integral part of solar radiation and can act either as a stress inducer or as a developmental signal. In recent years, increasing attention has been paid to the low-fluence UV-B-induced photomorphogenic response and several key players in this response have been identified, which include UVR8 (a UV-B-specific photoreceptor), COP1 (a WD40-repeat-containing RING finger protein), HY5 (a basic zipper transcription factor), and RUP1/2 (two UVR8-interacting proteins). Here we report that Arabidopsis SALT TOLERANCE (STO/BBX24), a known regulator for light signaling in plants, defines a new signaling component in UV-B-mediated photomorphogenesis. The bbx24 mutant is hypersensitive to UV-B radiation and becomes extremely dwarfed under UV-B treatment. By contrast, BBX24 overexpression transgenic lines respond much more weakly to UV-B than the bbx24 and wild-type plants. BBX24 expression is UV-B-inducible and its accumulation under UV-B requires COP1. Co-immunoprecipitation experiments indicate that BBX24 interacts with COP1 in planta upon UV-B illumination. Moreover, BBX24 interacts with HY5 and acts antagonistically with HY5 in UV-B-induced inhibition of hypocotyl elongation. Furthermore, BBX24 attenuates UV-B-induced HY5 accumulation and suppresses its transcription-activation activity. Taken together, our results reveal a previously uncharacterized function of the light-regulated BBX24 in UV-B responses and demonstrate that BBX24 functions as a negative regulator of photomorphogenic UV-B responses by interacting with both COP1 and HY5. The UV-B-inducible expression pattern and its suppression of HY5 activity suggest that BBX24 could be a new component of the feedback regulatory module of UV-B signaling in plants.
著者Jiang L, Wang Y, Li QF, Bjorn LO, He JX, Li SS
期刊名稱Cell Research
出版年份2012
月份6
日期1
卷號22
期次6
出版社INST BIOCHEMISTRY & CELL BIOLOGY
頁次1046 - 1057
國際標準期刊號1001-0602
電子國際標準期刊號1748-7838
語言英式英語
關鍵詞Arabidopsis thaliana; COP1; HY5; photomorphogenesis; STO/BBX24; UV-B
Web of Science 學科類別Cell Biology; CELL BIOLOGY

上次更新時間 2020-15-09 於 01:47