Arabidopsis Serrate Coordinates Histone Methyltransferases ATXR5/6 and RNA Processing Factor RDR6 to Regulate Transposon Expression

作者：Ma, Zeyang; Castillo-Gonzalez, Claudia; Wang, Zhiye; Sun, Di; Hu, Xiaomei; Shen, Xuefeng; Potok, Magdalena E.; Zhang, Xiuren^*

来源：Developmental Cell, 2018, 45(6): 769-+.

DOI：10.1016/j.devcel.2018.05.023

• DIRECTED DNA METHYLATION
• CAP-BINDING COMPLEX
• EPIGENETIC PATHWAY
• GENE-EXPRESSION
• QUALITY-CONTROL
• PLANTS
• THALIANA
• REPLICATION
• BIOGENESIS
• PROTEIN

Serrate (SE) is a key component in RNA metabolism. Little is known about whether and how it can regulate epigenetic silencing. Here, we report histone methyl-transferases ATXR5 and ATXR6 (ATXR5/6) as novel partners of SE. ATXR5/6 deposit histone 3 lysine 27 monomethylation (H3K27me1) to promote heterochromatin formation, repress transposable elements (TEs), and control genome stability in Arabidopsis. SE binds to ATXR5/6-regulated TE loci and promotes H3K27me1 accumulation in these regions. Furthermore, SE directly enhances ATXR5 enzymatic activity in vitro. Unexpectedly, se mutation suppresses the TE reactivation and DNA re-replication phenotypes in the atxr5 atxr6 mutant. The suppression of TE expression results from triggering RNA-dependent RNA polymerase 6 (RDR6)-dependent RNA silencing in the se atxr5 atxr6 mutant. We propose that SE facilitates ATXR5/6-mediated deposition of the H3K27me1 mark while inhibiting RDR6-mediated RNA silencing to protect TE transcripts. Hence, SE coordinates epigenetic silencing and RNA processing machineries to fine-tune the TE expression.

• 出版日期2018-6-18
• 单位华南农业大学