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Arabidopsis STO/BBX24 negatively regulates UV-B signaling by interacting with COP1 and repressing HY5 transcriptional activity

Jiang, Lei; Wang, Yan; Li, Qian-Feng; Björn, Lars Olof LU ; He, Jun-Xian and Li, Shao-Shan (2012) In Cell Research 22. p.1046-1057
Abstract
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... (More)
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. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Arabidopsis thaliana, HY5, COP1, STO/BBX24, photomorphogenesis, UV-B
in
Cell Research
volume
22
pages
1046 - 1057
publisher
Science Press
external identifiers
  • wos:000304817300011
  • scopus:84862832310
ISSN
1748-7838
DOI
10.1038/cr.2012.34
project
Photobiology
language
English
LU publication?
yes
id
04bc5b46-b7b5-45c0-aa6d-cb29821f6308 (old id 2860496)
date added to LUP
2012-08-30 15:06:03
date last changed
2017-11-19 03:02:10
@article{04bc5b46-b7b5-45c0-aa6d-cb29821f6308,
  abstract     = {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.<br/><br>
BBX24 expression is UV-B-inducible and its accumulation under UV-B requires COP1. Co-immunoprecipitation<br/><br>
experiments indicate that BBX24 interacts with COP1 in planta upon UV-B illumination. Moreover, BBX24 interacts<br/><br>
with HY5 and acts antagonistically with HY5 in UV-B-induced inhibition of hypocotyl elongation. Furthermore,<br/><br>
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.},
  author       = {Jiang, Lei and Wang, Yan and Li, Qian-Feng and Björn, Lars Olof and He, Jun-Xian and Li, Shao-Shan},
  issn         = {1748-7838},
  keyword      = {Arabidopsis thaliana,HY5,COP1,STO/BBX24,photomorphogenesis,UV-B},
  language     = {eng},
  pages        = {1046--1057},
  publisher    = {Science Press},
  series       = {Cell Research},
  title        = {Arabidopsis STO/BBX24 negatively regulates UV-B signaling by interacting with COP1 and repressing HY5 transcriptional activity},
  url          = {http://dx.doi.org/10.1038/cr.2012.34},
  volume       = {22},
  year         = {2012},
}