Co-recognition of histone acetylation and H3K4 trimethylation by GTE4-EML complex in Arabidopsis

Abstract

AbstractAlthough histone acetylation and H3K4 trimethylation (H3K4me3) are well-known histone marks associated with active transcription, how they cooperate to regulate transcription remains largely unclear in plants. Our study revealed that the Bromodomain and Extra-terminal (BET) protein GTE4 binds to acetylated histone and forms a complex with the redundant H3K4me3-binding EMSY-Likeproteins EML1 or EML2 (EML1/2) inArabidopsis thaliana. Theeml1 eml2(eml1/2) double mutant exhibited a morphological phenotype similar to thegte4mutant, and most of thegte4-mediated differentially expressed genes were co-regulated in theeml1/2mutant. Through chromatin immunoprecipitation followed by deep sequencing (ChIP-seq), we found that GTE4 and EML2 co-occupy protein-coding genes enriched with both histone acetylation and H3K4me3, exhibiting a synergistic effect on the association of the GTE4-EML complex with chromatin. The association of GTE4 with chromatin requires both the Bromodomain and the EML-interacting domain. This study identified a previously uncharacterized complex and uncovered how it cooperatively recognizes histone acetylation and H3K4me3 to facilitate gene transcription at the whole-genome level in Arabidopsis.