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:Plant BBR/BPC transcription factors contain the conserved Basic-Pentacystein (BPC) DNA-binding domain. Arabidopsis group II BBR/BPC proteins interact with PRC1 component LHP1 in vivo. Microarray experiments with Arabidopsis bpc4 bpc6, lhp1-4 and lhp1-4 bpc4 bpc6 suggest an importance of this interaction in the concerted repression of homeotic genes. In this study, we used the ATH1 GeneChip microarray to investigate transcript abundance in different Arabidopsis thaliana genotypes.
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:Plant BBR/BPC transcription factors contain the conserved Basic-Pentacystein (BPC) DNA-binding domain. Arabidopsis group II BBR/BPC proteins interact with PRC1 component LHP1 in vivo. Microarray experiments with Arabidopsis bpc4 bpc6, lhp1-4 and lhp1-4 bpc4 bpc6 suggest an importance of this interaction in the concerted repression of homeotic genes. In this study, we used the ATH1 GeneChip microarray to investigate transcript abundance in different Arabidopsis thaliana genotypes. Arabidopsis thaliana (accession Columbia) were grown in the greenhouse under constant temperature of 20°C, 35% humidity and a 18-h light period. 18 days old plants were harvested and immediately frozen in liquid nitrogen. Six individual plants were pooled per replicate.
Project description:BACKGROUND: Polycomb group complexes PRC1 and PRC2 repress gene expression at the chromatin level in eukaryotes. The classic recruitment model of Polycomb group complexes in which PRC2-mediated H3K27 trimethylation recruits PRC1 for H2A monoubiquitination was recently challenged by data showing that PRC1 activity can also recruit PRC2. However, the prevalence of these two mechanisms is unknown, especially in plants as H2AK121ub marks were examined at only a handful of Polycomb group targets. RESULTS: By using genome-wide analyses, we show that H2AK121ub marks are surprisingly widespread in Arabidopsis thaliana, often co-localizing with H3K27me3 but also occupying a set of transcriptionally active genes devoid of H3K27me3. Furthermore, by profiling H2AK121ub and H3K27me3 marks in atbmi1a/b/c, clf/swn, and lhp1 mutants we found that PRC2 activity is not required for H2AK121ub marking at most genes. In contrast, loss of AtBMI1 function impacts the incorporation of H3K27me3 marks at most Polycomb group targets. CONCLUSIONS: Our findings show the relationship between H2AK121ub and H3K27me3 marks across the A. thaliana genome and unveil that ubiquitination by PRC1 is largely independent of PRC2 activity in plants, while the inverse is true for H3K27 trimethylation.
Project description:BACKGROUND: Polycomb group complexes PRC1 and PRC2 repress gene expression at the chromatin level in eukaryotes. The classic recruitment model of Polycomb group complexes in which PRC2-mediated H3K27 trimethylation recruits PRC1 for H2A monoubiquitination was recently challenged by data showing that PRC1 activity can also recruit PRC2. However, the prevalence of these two mechanisms is unknown, especially in plants as H2AK121ub marks were examined at only a handful of Polycomb group targets. RESULTS: By using genome-wide analyses, we show that H2AK121ub marks are surprisingly widespread in Arabidopsis thaliana, often co-localizing with H3K27me3 but also occupying a set of transcriptionally active genes devoid of H3K27me3. Furthermore, by profiling H2AK121ub and H3K27me3 marks in atbmi1a/b/c, clf/swn, and lhp1 mutants we found that PRC2 activity is not required for H2AK121ub marking at most genes. In contrast, loss of AtBMI1 function impacts the incorporation of H3K27me3 marks at most Polycomb group targets. CONCLUSIONS: Our findings show the relationship between H2AK121ub and H3K27me3 marks across the A. thaliana genome and unveil that ubiquitination by PRC1 is largely independent of PRC2 activity in plants, while the inverse is true for H3K27 trimethylation.
