The Arabidopsis SWI2/SNF2 chromatin Remodeler BRAHMA regulates polycomb function during vegetative development and directly activates the flowering repressor gene SVP
| Autor: | Katherine A. Siminovitch, Chenlong Li, Keqiang Wu, Chen Chen, Shangzhi Huang, Lei Gao, Songguang Yang, Yuhai Cui, Vi Nguyen, Xuemei Chen, Xuejiang Shi, Susanne E. Kohalmi |
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| Přispěvatelé: | Schubert, Daniel |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Cancer Research
animal structures lcsh:QH426-470 Chromosomal Proteins Non-Histone 1.1 Normal biological development and functioning Arabidopsis Repressor Polycomb-Group Proteins Flowers macromolecular substances Histones Histone H3 Underpinning research Gene Expression Regulation Plant Genetics Polycomb-group proteins Molecular Biology Genetics (clinical) Ecology Evolution Behavior and Systematics Regulation of gene expression Adenosine Triphosphatases Genome biology Arabidopsis Proteins Human Genome fungi Non-Histone Plant biology.organism_classification Chromatin Assembly and Disassembly Chromatin Chromosomal Proteins Plant Leaves lcsh:Genetics Histone Gene Expression Regulation Seedlings biology.protein Chromatin immunoprecipitation Genome Plant Biotechnology Developmental Biology Research Article Transcription Factors |
| Zdroj: | PLoS Genetics, Vol 11, Iss 1, p e1004944 (2015) PLoS Genetics PLoS genetics, vol 11, iss 1 |
| ISSN: | 1553-7404 1553-7390 |
| Popis: | The chromatin remodeler BRAHMA (BRM) is a Trithorax Group (TrxG) protein that antagonizes the functions of Polycomb Group (PcG) proteins in fly and mammals. Recent studies also implicate such a role for Arabidopsis (Arabidopsis thaliana) BRM but the molecular mechanisms underlying the antagonism are unclear. To understand the interplay between BRM and PcG during plant development, we performed a genome-wide analysis of trimethylated histone H3 lysine 27 (H3K27me3) in brm mutant seedlings by chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq). Increased H3K27me3 deposition at several hundred genes was observed in brm mutants and this increase was partially supressed by removal of the H3K27 methyltransferase CURLY LEAF (CLF) or SWINGER (SWN). ChIP experiments demonstrated that BRM directly binds to a subset of the genes and prevents the inappropriate association and/or activity of PcG proteins at these loci. Together, these results indicate a crucial role of BRM in restricting the inappropriate activity of PcG during plant development. The key flowering repressor gene SHORT VEGETATIVE PHASE (SVP) is such a BRM target. In brm mutants, elevated PcG occupancy at SVP accompanies a dramatic increase in H3K27me3 levels at this locus and a concomitant reduction of SVP expression. Further, our gain- and loss-of-function genetic evidence establishes that BRM controls flowering time by directly activating SVP expression. This work reveals a genome-wide functional interplay between BRM and PcG and provides new insights into the impacts of these proteins in plant growth and development. Author Summary In flowering plants, the proper transition from vegetative growth to flowering is critical for their reproductive success and must be controlled precisely. Multiple genes have been shown to regulate the floral transition in response to environmental and endogenous cues. Among them is SHORT VEGETATIVE PHASE (SVP), a key flowering repressor gene in Arabidopsis. SVP is highly expressed during the vegetative phase to promote growth, but the mechanism by which the high expression level of SVP is maintained remains unknown. Here, we report a genome-wide study to examine the functional interplay between the BRM chromatin remodeler and the PcG proteins that catalyze trimethylation of lysine 27 on histone H3 (H3K27me3), a histone mark normally associated with transcriptionally repressed genes. We identify BRM as a direct upstream activator of SVP. BRM acts to keep the levels of H3K27me3 low at the SVP locus by inhibiting the binding and activities of the PcG proteins. Thus, our work identifies a previously unknown mechanism in regulation of flowering time and demonstrates the power of genome-wide approaches in dissecting regulatory networks controlling plant development. |
| Databáze: | OpenAIRE |
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