title: REPRESSOR OF SILENCING5 Encodes a Member of the Small Heat Shock Protein Family and Is Required for DNA Demethylation in Arabidopsis.
abstract: In Arabidopsis thaliana, active DNA demethylation is initiated by the DNA glycosylase REPRESSOR OF SILENCING1 (ROS1) and its paralogs DEMETER, DEMETER-LIKE2 (DML2), and DML3. How these demethylation enzymes are regulated, however, is poorly understood. Here, using a transgenic Arabidopsis line harboring the stress-inducible RESPONSIVE TO DEHYDRATION29A (RD29A) promoter-LUCIFERASE (LUC) reporter gene and the cauliflower mosaic virus 35S promoter (35S)-NEOMYCIN PHOSPHOTRANSFERASE II (NPTII) antibiotic resistance marker gene, we characterize a ROS locus, ROS5, that encodes a protein in the small heat shock protein family. ROS5 mutations lead to the silencing of the 35S-NPTII transgene due to DNA hypermethylation but do not affect the expression of the RD29A-LUC transgene. ROS5 physically interacts with the histone acetyltransferase ROS4/INCREASED DNA METHYLATION1 (IDM1) and is required to prevent the DNA hypermethylation of some genes that are also regulated by ROS1 and IDM1. We propose that ROS5 regulates DNA demethylation by interacting with IDM1, thereby creating a chromatin environment that facilitates the binding of ROS1 to erase DNA methylation.
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Yusheng
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Shaojun
authors.initials: S
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaojie
authors.initials: X
authors.lastname: Li
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China.
authors.forename: Chunlei
authors.initials: C
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China.
authors.forename: Zhongzhou
authors.initials: Z
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Agrobiotechnology, China Agricultural University, Beijing 100193, China National Maize Improvement Center, Department of Plant Genetics and Breeding, China Agricultural University, Beijing 100193, China.
authors.forename: Jinsheng
authors.initials: J
authors.lastname: Lai
authors.affiliation: State Key Laboratory of Plant Physiology and Biochemistry, College of Biological Sciences, China Agricultural University, Beijing 100193, China National Center for Plant Gene Research, Beijing 100193, China gongzz@cau.edu.cn.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Gong