Volume 21, No 12, Dec 2011
ISSN: 1001-0602
EISSN: 1748-7838 2018
impact factor 17.848*
(Clarivate Analytics, 2019)
Volume 21 Issue 12, December 2011: 1691-1700
ORIGINAL ARTICLES
An atypical component of RNA-directed DNA methylation machinery has both DNA methylation-dependent and -independent roles in locus-specific transcriptional gene silencing
Jun Liu1,*, Ge Bai2,3,*, Cuijun Zhang1,*, Wei Chen2, Jinxing Zhou1, Suwei Zhang1, Qing Chen1, Xin Deng2,4, Xin-Jian He1 and Jian-Kang Zhu2
1National Institute of Biological Sciences, Beijing 102206, China
2Department of Horticulture and Landscape Architecture, Purdue University, West Lafayette, IN 47907, USA
3School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China
4Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
Correspondence: Xin-Jian He,(hexinjian@nibs.ac.cn)
RNA-directed DNA methylation (RdDM) is an important de novo DNA methylation pathway in plants. RdDM mediates the transcriptional silencing of many endogenous genomic loci, most of which are transposon related. A forward genetics screen identified DTF1 (DNA-binding transcription factor 1) as a new component for RdDM in Arabidopsis. Loss-of-function mutations in DTF1 release the transcriptional silencing of RdDM target loci and reduce the accumulation of 24-nt small interfering RNAs (siRNAs) from some of the targets. Interestingly, in the dtf1 mutant plants, the release of transcriptional gene silencing at solo-LTR is accompanied by decreased siRNA accumulation but not by reduced DNA methylation. These results suggest that DTF1 is an atypical component of RdDM and has both DNA methylation-dependent and -independent roles in transcriptional gene silencing. We suggest that besides DNA methylation, siRNAs may cause some other uncharacterized epigenetic modifications that lead to transcriptional gene silencing.
DTF1; siRNA; DNA methylation; transcriptional gene silencing; RdDM
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