A histone H3K27me3 reader cooperates with a family of PHD finger‐containing proteins to regulate flowering time in Arabidopsis

Abstract

Trimethylated histone H3 lysine 27 (H3K27me3) is a repressive histone marker that regulates a variety of developmental processes, including those that determine flowering time. However, relatively little is known about the mechanism of how H3K27me3 is recognized to regulate transcription. Here, we identified BAH domain‐containing transcriptional regulator 1 (BDT1) as an H3K27me3 reader. BDT1 is responsible for preventing flowering by suppressing the expression of flowering genes. Mutation of the H3K27me3 recognition sites in the BAH domain disrupted the binding of BDT1 to H3K27me3, leading to de‐repression of H3K27me3‐enriched flowering genes and an early‐flowering phenotype. We also found that BDT1 interacts with a family of PHD finger‐containing proteins, which we named PHD1–6, and with CPL2, a Pol II carboxyl terminal domain (CTD) phosphatase responsible for transcriptional repression. Pull‐down assays showed that the PHD finger‐containing proteins can enhance the binding of BDT1 to the H3K27me3 peptide. Mutations in all of the PHD genes caused increased expression of flowering genes and an early‐flowering phenotype. This study suggests that the binding of BDT1 to the H3K27me3 peptide, which is enhanced by PHD proteins, is critical for preventing early flowering.

The MOM1 complex recruits the RdDM machinery via MORC6 to establishde novoDNA methylation

“…1a and Supplementary Table 1). Previous IP-MS of the AIPP3 protein pulled down other protein components such as PHD2 (also called PAIPP2), PHD3 (also called AIPP2) and CPL2, in addition to PHD1 [44][45][46] . To facilitate the dissection of the interacting components, we performed IP-MS with FLAG tagged MOM2, PIAL2, PHD1 and AIPP3.…”

Dynamics of H3K27me3 Modification on Plant Adaptation to Environmental Cues

“…In contrast, EBS and SHL are dual readers that recognize H3K27me3 and H3K4me2/3 through N-terminal BAH domain and C-terminal PHD domain, respectively [99][100][101]. Similarly, BDT1 and AIPP3 also use the BAH domain to bind to H3K27me3, facilitating the suppression of the expression of flowering genes, thus preventing flowering [102,103]. Therefore, LHP1, EBS, SHL, BDT1, and AIPP3 represent different readers of the H3K27me3 and are relevant for repression of PRC2 targets [9,[97][98][99][100][101][102][103][104].…”

“…Similarly, BDT1 and AIPP3 also use the BAH domain to bind to H3K27me3, facilitating the suppression of the expression of flowering genes, thus preventing flowering [102,103]. Therefore, LHP1, EBS, SHL, BDT1, and AIPP3 represent different readers of the H3K27me3 and are relevant for repression of PRC2 targets [9,[97][98][99][100][101][102][103][104]. Remarkably, homologs of Drosophila Ph are lost in plants, instead EMF1 (phenocopying emf2) has been proposed to be a plant-specific PRC1 component that mediates chromatin compaction [68,105,106].…”

Transcriptomic Insight into Underground Floral Differentiation in Erythronium japonicum

“…Thus, further functional analysis of ELF3 can provide valuable insights into its role in regulating floral differentiation in E. japonicum. Similarly, other DEGs identified with differential expression at early stages of floral differentiation, including PHD [68][69][70], cullin 1 [71], SE14 [72], ZSWIM3 [73], GIGNATEA [74], and SERPIN B [75], have been characterized for their positive role in the regulation of flowering in different plant species with their potential involvement in circadian pathways.…”