PMID- 27325768
OWN - NLM
STAT- MEDLINE
DCOM- 20170814
LR  - 20190806
IS  - 1091-6490 (Electronic)
IS  - 0027-8424 (Print)
IS  - 0027-8424 (Linking)
VI  - 113
IP  - 27
DP  - 2016 Jul 5
TI  - BBX21, an Arabidopsis B-box protein, directly activates HY5 and is targeted by 
      COP1 for 26S proteasome-mediated degradation.
PG  - 7655-60
LID - 10.1073/pnas.1607687113 [doi]
AB  - BBX21 (also known as SALT TOLERANCE HOMOLOG 2), a B-box (BBX)-containing protein, 
      has been previously identified as a positive regulator of light signaling; 
      however, the precise role of BBX21 in regulating seedling photomorphogenesis 
      remains largely unclear. In this study, we report that CONSTITUTIVELY 
      PHOTOMORPHOGENIC 1 (COP1) interacts with BBX21 in vivo and is able to 
      ubiquitinate BBX21 in vitro. Thus, BBX21 is targeted for 26S proteasome-mediated 
      degradation in dark-grown Arabidopsis seedlings in a COP1-dependent manner. 
      Moreover, we show that BBX21 binds to the T/G-box in the ELONGATED HYPOCOTYL 5 
      (HY5) promoter and directly activates HY5 expression in the light. Transgenic 
      seedlings overexpressing BBX21 exhibit dramatically shortened hypocotyls in the 
      light, and this phenotype is dependent on a functional HY5. Taken together, our 
      data suggest a molecular base underlying BBX21-mediated seedling 
      photomorphogenesis, indicating that BBX21 is a pivotal component involved in the 
      COP1-HY5 regulatory hub.
FAU - Xu, Dongqing
AU  - Xu D
AD  - State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center 
      for Life Sciences, School of Advanced Agriculture Sciences and School of Life 
      Sciences, Peking University, Beijing 100871, China;
FAU - Jiang, Yan
AU  - Jiang Y
AD  - State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center 
      for Life Sciences, School of Advanced Agriculture Sciences and School of Life 
      Sciences, Peking University, Beijing 100871, China;
FAU - Li, Jigang
AU  - Li J
AD  - State Key Laboratory of Plant Physiology and Biochemistry, College of Biological 
      Sciences, China Agricultural University, Beijing 100193, China;
FAU - Lin, Fang
AU  - Lin F
AD  - State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center 
      for Life Sciences, School of Advanced Agriculture Sciences and School of Life 
      Sciences, Peking University, Beijing 100871, China;
FAU - Holm, Magnus
AU  - Holm M
AD  - Department of Biological and Environmental Sciences, Gothenburg University, 
      SE-405 30 Gothenburg, Sweden.
FAU - Deng, Xing Wang
AU  - Deng XW
AD  - State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center 
      for Life Sciences, School of Advanced Agriculture Sciences and School of Life 
      Sciences, Peking University, Beijing 100871, China; deng@pku.edu.cn.
LA  - eng
GR  - R01 GM047850/GM/NIGMS NIH HHS/United States
GR  - R37 GM047850/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20160620
PL  - United States
TA  - Proc Natl Acad Sci U S A
JT  - Proceedings of the National Academy of Sciences of the United States of America
JID - 7505876
RN  - 0 (Arabidopsis Proteins)
RN  - 0 (BBX21 protein, Arabidopsis)
RN  - 0 (Basic-Leucine Zipper Transcription Factors)
RN  - 0 (HY5 protein, Arabidopsis)
RN  - 0 (Nuclear Proteins)
RN  - 0 (Transcription Factors)
RN  - EC 2.3.2.27 (AT2G32950 protein, Arabidopsis)
RN  - EC 2.3.2.27 (Ubiquitin-Protein Ligases)
RN  - EC 3.4.25.1 (Proteasome Endopeptidase Complex)
RN  - EC 3.4.99.- (ATP dependent 26S protease)
SB  - IM
MH  - Arabidopsis/growth & development/*metabolism
MH  - Arabidopsis Proteins/*metabolism
MH  - Basic-Leucine Zipper Transcription Factors/*metabolism
MH  - Gene Expression/radiation effects
MH  - Gene Expression Regulation, Plant
MH  - Light
MH  - Nuclear Proteins/*metabolism
MH  - Plants, Genetically Modified
MH  - Proteasome Endopeptidase Complex/*metabolism
MH  - Transcription Factors/*metabolism
MH  - Ubiquitin-Protein Ligases/*metabolism
MH  - Ubiquitination
PMC - PMC4941485
OTO - NOTNLM
OT  - Arabidopsis
OT  - BBX21
OT  - COP1
OT  - HY5
OT  - photomorphogenesis
COIS- The authors declare no conflict of interest.
EDAT- 2016/06/22 06:00
MHDA- 2017/08/15 06:00
PMCR- 2017/01/05
CRDT- 2016/06/22 06:00
PHST- 2016/06/22 06:00 [entrez]
PHST- 2016/06/22 06:00 [pubmed]
PHST- 2017/08/15 06:00 [medline]
PHST- 2017/01/05 00:00 [pmc-release]
AID - 1607687113 [pii]
AID - 201607687 [pii]
AID - 10.1073/pnas.1607687113 [doi]
PST - ppublish
SO  - Proc Natl Acad Sci U S A. 2016 Jul 5;113(27):7655-60. doi: 
      10.1073/pnas.1607687113. Epub 2016 Jun 20.