HY5 stability and activity in arabidopsis is regulated by phosphorylation in its COP1 binding domain

Détails

ID Serval
serval:BIB_2D96CB4AFD5D
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
HY5 stability and activity in arabidopsis is regulated by phosphorylation in its COP1 binding domain
Périodique
EMBO Journal
Auteur(s)
Hardtke  C. S., Gohda  K., Osterlund  M. T., Oyama  T., Okada  K., Deng  X. W.
ISSN
0261-4189 (Print)
Statut éditorial
Publié
Date de publication
09/2000
Volume
19
Numéro
18
Pages
4997-5006
Notes
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S. --- Old month value: Sep 15
Résumé
Arabidopsis HY5 is a bZIP transcription factor that promotes photomorphogenesis. Previous studies suggested that COP1, a negative regulator of photomorphogenesis, directly interacts with nuclear HY5 and targets it for proteasome-mediated degradation. Light negatively regulates the nuclear level of COP1 and thus permits HY5 accumulation. Here we report that HY5 abundance peaks in early seedling development, consistent with its role in promoting photomorphogenesis. HY5 acts exclusively within a complex and exists in two isoforms, resulting from phosphorylation within its COP1 binding domain by a light- regulated kinase activity. Unphosphorylated HY5 shows stronger interaction with COP1, is the preferred substrate for degradation, has higher affinity to target promoters and is physiologically more active than the phosphorylated version. Therefore, HY5 phosphorylation provides an added level of light-mediated regulation of HY5 stability and activity besides nuclear COP1 levels. Regulated HY5 phosphorylation not only provides abundant and physiologically more active unphosphorylated HY5 in the light, but also helps to maintain a small pool of less active phosphorylated HY5 in the dark, which could be essential for a rapid initial response during dark-to-light transition.
Mots-clé
Amino Acid Sequence Arabidopsis/*chemistry *Arabidopsis Proteins Basic-Leucine Zipper Transcription Factors Binding Sites Blotting, Western Carrier Proteins/chemistry/*metabolism Casein Kinase II Cell Nucleus/metabolism Chromatography, Gel Glutathione Transferase/metabolism Light Molecular Sequence Data Nuclear Proteins/*chemistry/*genetics/*metabolism Phosphorylation Plant Proteins/chemistry/*metabolism Plants, Genetically Modified Precipitin Tests Promoter Regions (Genetics) Protein Isoforms Protein Structure, Tertiary Protein-Serine-Threonine Kinases/metabolism Recombinant Fusion Proteins/chemistry/metabolism Sequence Homology, Amino Acid Time Factors Tissue Distribution Transcription Factors/chemistry/metabolism Transgenes Two-Hybrid System Techniques *Ubiquitin-Protein Ligases
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 20:51
Dernière modification de la notice
08/05/2019 16:28
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