An Effector of RNA-Directed DNA Methylation in Arabidopsis Is an ARGONAUTE 4-and RNA-Binding Protein

被引：208

作者：

He, Xin-Jian ^{[1
,2
]}

Hsu, Yi-Feng ^{[1
,2
,4
]}

Zhu, Shihua ^{[1
,2
,5
]}

Wierzbicki, Andrzej T. ^{[6
]}

Pontes, Olga ^{[6
]}

Pikaard, Craig S. ^{[6
]}

Liu, Hai-Liang ^{[1
,2
]}

Wang, Co-Shine ^{[4
]}

Jin, Hailing ^{[1
,3
]}

Zhu, Jian-Kang ^{[1
,2
]}

机构：

[1] Univ Calif Riverside, Inst Integrat Genome Biol, Riverside, CA 92521 USA

[2] Univ Calif Riverside, Dept Bot & Plant Sci, Riverside, CA 92521 USA

[3] Univ Calif Riverside, Dept Plant Pathol, Riverside, CA 92521 USA

[4] Natl Chung Hsing Univ, Grad Inst Biotechnol, Taichung 40227, Taiwan

[5] Ningbo Univ, Coll Sci & Technol, Ningbo 315211, Zhejiang, Peoples R China

[6] Washington Univ, Dept Biol, St Louis, MO 63130 USA

来源：

CELL | 2009年 / 137卷 / 03期

基金：

美国国家科学基金会; 美国国家卫生研究院;

关键词：

GLYCOSYLASE/LYASE ROS1; POLYMERASE-II; TRANSCRIPTION; HETEROCHROMATIN; ROLES; SPT5; IV; MAINTENANCE; SUBUNIT; RITS;

D O I：

10.1016/j.cell.2009.04.028

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

DNA methylation is a conserved epigenetic mark in plants and mammals. In Arabidopsis, DNA methylation can be triggered by small interfering RNAs (siRNAs) through an RNA-directed DNA methylation (RdDM) pathway. Here, we report the identification of an RdDM effector, KTF1. Loss-of-function mutations in KTF1 reduce DNA methylation and release the silencing of RdDM target loci without abolishing the siRNA triggers. KTF1 has similarity to the transcription elongation factor SPT5 and contains a C-terminal extension rich in GW/WG repeats. KTF1 colocalizes with ARGONAUTE 4 (AGO4) in punctate nuclear foci and binds AGO4 and RNA transcripts. Our results suggest KTF1 as an adaptor protein that binds scaffold transcripts generated by Pol V and recruits AGO4 and AGO4-bound siRNAs to form an RdDM effector complex. The dual interaction of an effector protein with AGO and small RNA target transcripts may be a general feature of RNA-silencing effector complexes.

引用

页码：498 / 508

页数：11

共 43 条

[1] Role of the Arabidopsis DNA glycosylase/lyase ROS1 in active DNA demethylation [J].