The degradation of HFR1, a putative bHLH class transcription factor involved in light signaling, is regulated by phosphorylation and requires COP1.

Details

Serval ID
serval:BIB_1F398A440B22
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The degradation of HFR1, a putative bHLH class transcription factor involved in light signaling, is regulated by phosphorylation and requires COP1.
Journal
Current Biology
Author(s)
Duek P.D., Elmer M.V., van Oosten V.R., Fankhauser C.
ISSN
0960-9822[print], 0960-9822[linking]
Publication state
Published
Issued date
2004
Peer-reviewed
Oui
Volume
14
Number
24
Pages
2296-2301
Language
english
Abstract
All developmental transitions throughout the life cycle of a plant are influenced by light. In Arabidopsis, multiple photoreceptors including the UV-A/blue-sensing cryptochromes (cry1-2) and the red/far-red responsive phytochromes (phyA-E) monitor the ambient light conditions. Light-regulated protein stability is a major control point of photomorphogenesis. The ubiquitin E3 ligase COP1 (constitutively photomorphogenic 1) regulates the stability of several light-signaling components. HFR1 (long hypocotyl in far-red light) is a putative transcription factor with a bHLH domain acting downstream of both phyA and the cryptochromes. HFR1 is closely related to PIF1, PIF3, and PIF4 (phytochrome interacting factor 1, 3 and 4), but in contrast to the latter three, there is no evidence for a direct interaction between HFR1 and the phytochromes. Here, we show that the protein abundance of HFR1 is tightly controlled by light. HFR1 is an unstable phosphoprotein, particularly in the dark. The proteasome and COP1 are required in vivo to degrade phosphorylated HFR1. In addition, HFR1 can interact with COP1, consistent with the idea of COP1 directly mediating HFR1 degradation. We identify a domain, conserved among several bHLH class proteins involved in light signaling , as a determinant of HFR1 stability. Our physiological experiments indicate that the control of HFR1 protein abundance is important for a normal de-etiolation response.
Keywords
Arabidopsis/metabolism, Arabidopsis Proteins/genetics, Arabidopsis Proteins/metabolism, Blotting, Western, Cryptochromes, DNA Primers, DNA, Complementary/genetics, DNA-Binding Proteins/genetics, DNA-Binding Proteins/metabolism, Flavoproteins/physiology, Genetic Vectors, Immunoprecipitation, Light, Nuclear Proteins/genetics, Nuclear Proteins/metabolism, Phosphorylation, Phytochrome/physiology, Plants, Genetically Modified, Rhizobium radiobacter, Signal Transduction, Transcription Factors/metabolism, Two-Hybrid System Techniques
Pubmed
Web of science
Open Access
Yes
Create date
24/01/2008 15:29
Last modification date
20/08/2019 12:55
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