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TOC1 clock protein phosphorylation controls complex formation with NF-YB/C to repress hypocotyl growth
- Source :
- EMBO J, EMBO Journal
- Publication Year :
- 2021
-
Abstract
- Plant photoperiodic growth is coordinated by interactions between circadian clock and light signaling networks. How post-translational modifications of clock proteins affect these interactions to mediate rhythmic growth remains unclear. Here, we identify five phosphorylation sites in the Arabidopsis core clock protein TIMING OF CAB EXPRESSION 1 (TOC1) which when mutated to alanine eliminate detectable phosphorylation. The TOC1 phospho-mutant fails to fully rescue the clock, growth, and flowering phenotypes of the toc1 mutant. Further, the TOC1 phospho-mutant shows advanced phase, a faster degradation rate, reduced interactions with PHYTOCHROME-INTERACTING FACTOR 3 (PIF3) and HISTONE DEACETYLASE 15 (HDA15), and poor binding at pre-dawn hypocotyl growth-related genes (PHGs), leading to a net de-repression of hypocotyl growth. NUCLEAR FACTOR Y subunits B and C (NF-YB/C) stabilize TOC1 at target promoters, and this novel trimeric complex (NF-TOC1) acts as a transcriptional co-repressor with HDA15 to inhibit PIF-mediated hypocotyl elongation. Collectively, we identify a molecular mechanism suggesting how phosphorylation of TOC1 alters its phase, stability, and physical interactions with co-regulators to precisely phase PHG expression to control photoperiodic hypocotyl growth.
- Subjects :
- Circadian clock
TOC1
Arabidopsis
General Biochemistry, Genetics and Molecular Biology
Histone Deacetylases
Hypocotyl
Gene Expression Regulation, Plant
Basic Helix-Loop-Helix Transcription Factors
Protein phosphorylation
CLOCK Proteins
Phosphorylation
Molecular Biology
General Immunology and Microbiology
biology
Arabidopsis Proteins
General Neuroscience
fungi
food and beverages
Articles
biology.organism_classification
Cell biology
CCAAT-Binding Factor
Mutation
Proteolysis
Histone deacetylase
Signal Transduction
Transcription Factors
Subjects
Details
- ISSN :
- 14602075
- Volume :
- 40
- Issue :
- 24
- Database :
- OpenAIRE
- Journal :
- The EMBO journal
- Accession number :
- edsair.doi.dedup.....9c9b0540683fc1a1e788c7c4e6b4e0ef