Targeting mechanism of H3K27me3 demethylase REF6 and its role in transgenerational thermomemory in Arabidopsis

<p>Xian Deng</p>

Targeting mechanism of H3K27me3 demethylase REF6 and its role in transgenerational thermomemory in Arabidopsis

Xian Deng

Chinese Academy of Sciences, China

: J Plant Physiol Pathol

Abstract

Relative of Early Flowering 6 (Ref6/Jmj12), a Jumonji C (JmjC)-domain-containing H3K27me3 histone demethylase, finds its target loci in Arabidopsis genome by directly recognizing the CTCTGYTY motif via its zinc-finger (ZnF) domains (1, 2). REF6 tends to bind motifs located in active chromatin states and depleted for heterochromatic modifications. However, the underlying mechanism remains unknown. Here, using biochemistry, structural biology, and high-throughput sequencing, we showed that REF6 binding affinity to specific regions is repelled by DNA methylation within CTCTGYTY motif. In addition, we also found that heatinduced Heat Shock Transcription Factor A2 (HSFA2) directly activates REF6, which in turn derepresses HSFA2. REF6 and HSFA2 establish a heritable feedback loop which is involved in transgene rational thermo memory and stress adaptation.