Project description:The POLYCOMB proteins are required for maintenance of silent chromatin states mediated by H3K27 trimethylation in animals, but POLYCOMB homologues are not found in plant genomes. Using DamID-chip, we found that the Arabidopsis chromodomain-containing protein LHP1 localizes to chromatin associated with H3K27me3 genome-wide. Furthermore, the LHP1 chromodomain binds H3K27me3 with high affinity. These results suggest that LHP1 shares similar functions with POLYCOMB. Keywords: DamID-Chip
Project description:By RNA deep sequencing, around 11,000 genes were found to be differentially expressed in ebs shl lhp1 compared with wild type, and SHL and EBS, together with LHP1 and EMF1, co-regulate the expression of thousands of gene in Arabidopsis
Project description:Transcriptome changes in leaves of PcG protein mutants clf and lhp1. Fully expanded rosette leaf 6 was collected from 10 35-d-old plants grown in short day photoperiods.
Project description:Precise expression patterns of genes in time and space are essential for proper development of multicellular organisms. Dynamic chromatin conformation and spatial organization of the genome constitute a major step in this regulation to modulate developmental outputs. Polycomb repressive complexes (PRCs) mediate stable or flexible gene repression in response to internal and environmental cues. In Arabidopsis thaliana, LHP1 co-localizes with H3K27me3 epigenetic marks throughout the genome and interacts with PRC1 and PRC2 members as well as with a long noncoding RNA. Here, we show that LHP1 is responsible for the spreading of H3K27me3 towards the 3' end of the gene body. We also identified a subset of LHP1-activated genes and demonstrated that LHP1 shapes local chromatin topology in order to control transcriptional co-regulation. Our work reveals a general role of LHP1 from local to higher conformation levels of chromatin configuration to determine its accessibility to define gene expression patterns.
Project description:RNA-seq was performed in order to identify qualitative variation of transcripts in clf-29 lhp1-4 compared to WT, including SNPS, indels, splicing fidelity
Project description:The Polycomb repressive complex 2 (PRC2) is an essential epigenetic regulator that deposits repressive H3K27me3 for transcriptional gene silencing in eukaryotes. The PRC2-mediated gene silencing process occurs in two steps: the initial H3K27me3 deposition at the nucleation region, and the subsequent spreading of H3K27me3 over the entire gene. Lack of H3K27me3 spreading gives rise to a metastable state that could lead to loss of silencing. H3K27me3 spreading is thus a key step critical for the establishment of stable long-term Polycomb silencing in both animals and plants.Here, we uncover that Arabidopsis thaliana PICKLE (PKL), a member of the conserved Chromodomain Helicase DNA-binding (CHD) family of chromatin remodeling ATPase13, is dispensable for the nucleation but especially required for the efficient spreading of H3K27me3 at thousands of Polycomb target genes. PKL localizes to the spreading regions in a non-DNA-sequence-specific manner through its SANT-SILDE domain. PKL then upregulates the chromatin density by its CHROMODOMAIN and ATPase domain , enabling the H3K27me3 methyltransferase CURLY LEAF (CLF) to deposit H3K27me3 on nucleosomes in the spreading regions to facilitate the H3K27me3 spreading.