Histone H2A monoubiquitination marks are targeted to specific sites by cohesin subunits in Arabidopsis

Abstract

Histone H2A monoubiquitination (H2Aub1) functions as a conserved posttranslational modification in eukaryotes to maintain gene expression and guarantee cellular identity. Arabidopsis H2Aub1 is catalyzed by the core components AtRING1s and AtBMI1s of polycomb repressive complex 1 (PRC1). Because PRC1 components lack known DNA binding domains, it is unclear how H2Aub1 is established at specific genomic locations. Here, we show that the Arabidopsis cohesin subunits AtSYN4 and AtSCC3 interact with each other, and AtSCC3 binds to AtBMI1s. H2Aub1 levels are reduced in atsyn4 mutant or AtSCC3 artificial microRNA knockdown plants. ChIP-seq assays indicate that most binding events of AtSYN4 and AtSCC3 are associated with H2Aub1 along the genome where transcription is activated independently of H3K27me3. Finally, we show that AtSYN4 binds directly to the G-box motif and directs H2Aub1 to these sites. Our study thus reveals a mechanism for cohesin-mediated recruitment of AtBMI1s to specific genomic loci to mediate H2Aub1.

Genome-Wide Identification of G-Quadruplex forming regions in Arabidopsis: Unraveling the Role of Pif like Helicase (AtPLH1) in Gene Regulation and Stress Response

“…Further, transcription factor enrichment analysis suggested enrichment of H3AK121ub and H3K27me3, LHP1, WRKY18, WRKY33, BBM, BIM2, RPL, ANAC017, HAT22 and HB6 ( Figure 3c) . Recently, H2AK121ub mark has been found to be associated with less accessible, but permissive chromatin at transcriptional regulation hotspots (Yin et al, 2021; Zhang et al, 2023). The LHP1 interaction with PRC1 catalyzes H2A monoubiquitination and with PRC2 establishes H3K27me3 (Feng and Lu, 2017).…”

Single-Cell RNA Sequencing Reveals Differences in Chromatin Remodeling and Energy Metabolism among In Vivo-Developed, In Vitro-Fertilized, and Parthenogenetically Activated Embryos from the Oocyte to 8-Cell Stages in Pigs

“…First, the key differentially expressed genes in maternal mRNA involve different chromatin remodeling complexes and various chromatin modifications, with a very small intersection evident in the first wave of minor ZGA. In the entire minor ZGA stage, the upregulated genes in all three types of embryos are involved in chromatin remodeling; among these, IVV embryos, compared to in vitro embryos, have more participating genes and a richer variety of regulation in H2A ubiquitination [53] and H4 acetylation, which may control nucleosome accessibility of promoters prior to ZGA [54]. In the major ZGA stage from the 2-to 4-cell stages, IVV further participates in the acetylation regulation of histones independently.…”