title: SUVH2 and SUVH9 Couple Two Essential Steps for Transcriptional Gene Silencing in Arabidopsis.
abstract: In Arabidopsis, an RNA-directed DNA methylation pathway (RdDM) is responsible for de novo establishment of DNA methylation and contributes to transcriptional gene silencing. Recently, the microrchidia (MORC)-type ATPases were shown to play essential roles in enforcing transcriptional gene silencing of a subset of genes and transposons by regulating the formation of higher-order chromatin architecture. However, how MORC proteins cooperate with the RdDM pathway components to regulate gene expression remains largely unclear. In this study, SUVH9 and MORC6 were identified from a screening of suppressors of idm1, which is a mutant defective in active DNA demethylation. SUVH9 and MORC6 are required for silencing of two reporter genes and some endogenous genes without enhancing DNA methylation levels. SUVH9, one of SU(VAR)3-9 homologs involved in RdDM, directly interacts with MORC6 and its two close homologs, MORC1 and MORC2. Similar to MORC6, SUVH9 and its homolog SUVH2 are required for heterochromatin condensation and formation of 3D chromatin architecture at SDC and Solo-LTR loci. We propose that SUVH2 and SUVH9 bind to the methylated DNA and facilitate the recruitment of a chromatin-remodeling complex to the target loci in association with MORC proteins.
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Jing
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Han
authors.initials: H
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Yuan
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Yannan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences, School of Life Sciences, Peking University, Beijing 100871, China. Electronic address: wqqian@pku.edu.cn.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Qian
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D020868:Gene Silencing / Q000502:physiology*; D011495:Histone-Lysine N-Methyltransferase / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D011495:Histone-Lysine N-Methyltransferase; C501526:SUVH2 protein, Arabidopsis; C587137:SUVH9 protein, Arabidopsis; D000251:Adenosine Triphosphatases
keywords: DNA methylation; MORC6 (At1g19100); SUVH9 (At4g13460); chromatin remodeling; epigenetics; transcriptional gene silencing