COP1 and ELF3 control circadian function and photoperiodic flowering by regulating GI stability.
Seasonal changes in day length are perceived by plant photoreceptors and transmitted to the circadian clock to modulate developmental responses such as flowering time. Blue-light-sensing cryptochromes, the E3 ubiquitin-ligase COP1, and clock-associated proteins ELF3 and GI regulate this process, although the regulatory link between them is unclear. Here we present data showing that COP1 acts with ELF3 to mediate day length signaling from CRY2 to GI within the photoperiod flowering pathway. We found that COP1 and ELF3 interact in vivo and show that ELF3 allows COP1 to interact with GI in vivo, leading to GI degradation in planta. Accordingly, mutation of COP1 or ELF3 disturbs the pattern of GI cyclic accumulation. We propose a model in which ELF3 acts as a substrate adaptor, enabling COP1 to modulate light input signal to the circadian clock through targeted destabilization of GI.
Yu
Jae-Woong
JW
Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
Rubio
Vicente
V
Lee
Na-Yeoun
NY
Bai
Sulan
S
Lee
Sun-Young
SY
Kim
Sang-Sook
SS
Liu
Lijing
L
Zhang
Yiyue
Y
Irigoyen
María Luisa
ML
Sullivan
James A
JA
Zhang
Yu
Y
Lee
Ilha
I
Xie
Qi
Q
Paek
Nam-Chon
NC
Deng
Xing Wang
XW
D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008954:Models, Biological; D009154:Mutation / Q000235:genetics; D017440:Photoperiod; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D055550:Protein Stability; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination
D029681:Arabidopsis Proteins; D046988:Proteasome Endopeptidase Complex; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases; C432430:At2g25930 protein, Arabidopsis; C121183:GI protein, Arabidopsis; C471983:AT2G32950 protein, Arabidopsis