DNA methylation mediated by a microRNA pathway.
In plants, the known microRNAs (miRNAs) are produced as approximately 21 nucleotide (nt) duplexes from their precursors by Dicer-like 1 (DCL1). They are incorporated into Argonaute 1 (AGO1) protein to regulate target gene expression primarily through mRNA cleavage. We report here the discovery of a class of miRNAs in the model monocot rice (Oryza sativa). These are 24 nt in length and require another member of the Dicer family, DCL3, for their biogenesis. The 24 nt long miRNAs (lmiRNAs) are loaded into AGO4 clade proteins according to hierarchical rules, depending on the upstream biogenesis machinery and the 5'-terminal nucleotide. We demonstrated that lmiRNAs direct DNA methylation at loci from which they are produced as well as in trans at their target genes and play roles in gene regulation. Considered together, our findings define a miRNA pathway that mediates DNA methylation.
Wu
Liang
L
National Institute of Biological Sciences, Zhongguancun Life Science Park, Beijing 102206, China; College of Life Sciences, Beijing Normal University, Beijing 100875, China.
Zhou
Huanyu
H
Zhang
Qingqing
Q
Zhang
Jianguang
J
Ni
Fangrui
F
Liu
Chang
C
Qi
Yijun
Y
D042002:Chromatin Assembly and Disassembly; D003596:Cytosine; D019175:DNA Methylation; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D021381:Protein Transport; D034622:RNA Interference; D012322:RNA Precursors / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism
D035683:MicroRNAs; D010940:Plant Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D018749:RNA, Plant; D003596:Cytosine; D043244:Ribonuclease III