Arabidopsis ARGONAUTE 1 Binds Chromatin to Promote Gene Transcription in Response to Hormones and Stresses

Publication date: Available online 28 December 2017
Source:Developmental Cell
Author(s): Chang Liu, Ying Xin, Le Xu, Zhaokui Cai, Yuanchao Xue, Yong Liu, Daoxin Xie, Yule Liu, Yijun Qi
Conventional RNA interference (RNAi) pathways suppress eukaryotic gene expression at the transcriptional or post-transcriptional level. At the core of RNAi are small RNAs (sRNAs) and effector Argonaute (AGO) proteins. Arabidopsis AGO1 is known to bind microRNAs (miRNAs) and post-transcriptionally repress target genes in the cytoplasm. Here, we report that AGO1 also binds to the chromatin of active genes and promotes their transcription. We show that sRNAs and SWI/SNF complexes associate with nuclear AGO1 and are required for AGO1 binding to chromatin. Moreover, we show that various stimuli, including plant hormones and stresses, specifically trigger AGO1 binding to stimulus-responsive genes. Finally, we show that AGO1 facilitates the induction of genes in jasmonate (JA) signaling pathways and the activation of JA responses. Our findings suggest that, by binding and facilitating the expression of stimuli-specific genes, AGO1 may regulate diverse signaling pathways and associated biological processes.

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Teaser

Argonaute (AGO) proteins are well known to bind small RNAs and direct post-transcriptional gene silencing. Liu et al. uncover an unsuspected role for Arabidopsis AGO1 in direct chromatin binding to promote gene transcription in responses to stimuli, including hormones and stresses. AGO1 binding requires small RNAs and the SWI/SNF chromatin-remodeling complexes.


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