FDDM1 and FDDM2, Two SGS3-like Proteins, Function as a Complex to Affect DNA Methylation in Arabidopsis

Authors

Shengjun Li, Chinese Academy of Sciences; University of Nebraska-LincolnFollow
Weilong Yang, University of Nebraska-LincolnFollow
Yunfeng LiuFollow
Guangyong Li, University of Nebraska-LincolnFollow
Xiang Liu, University of Nebraska-Lincoln; Chinese Academy of SciencesFollow
Yaling Liu, University of Nebraska-Lincoln; Shanxi Agricultural UniversityFollow
James R. Alfano, University of Nebraska-Lincoln
Chi Zhang, University of Nebraska-LincolnFollow
Bin Yu, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2022

Citation

Li, S.; Yang,W.; Liu, Y.; Li, G.; Liu, X.; Liu, Y.; Alfano, J.R.; Zhang, C.; Yu, B. FDDM1 and FDDM2, Two SGS3-like Proteins, Function as a Complex to Affect DNA Methylation in Arabidopsis. Genes 2022, 13, 339. https://doi.org/ 10.3390/genes13020339

Comments

© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Abstract

DNA methylation is an important epigenetic modification required for the specific regulation of gene expression and the maintenance of genome stability in plants and animals. However, the mechanism of DNA demethylation remains largely unknown. Here, we show that two SGS3-like proteins, FACTOR OF DNA DEMETHYLATION 1 (FDDM1) and FDDM2, negatively affect the DNA methylation levels at ROS1-dependend DNA loci in Arabidopsis. FDDM1 binds dsRNAs with 50 overhangs through its XS (rice gene X and SGS3) domain and forms a heterodimer with FDDM2 through its XH (rice gene X Homology) domain. A lack of FDDM1 or FDDM2 increased DNA methylation levels at several ROS1-dependent DNA loci. However, FDDM1 and FDDM2 may not have an additive effect on DNA methylation levels. Moreover, the XS and XH domains are required for the function of FDDM1. Taken together, these results suggest that FDDM1 and FDDM2 act as a heterodimer to positively modulate DNA demethylation. Our finding extends the function of plant-specific SGS3-like proteins.