Antagonistic cotranscriptional regulation through ARGONAUTE1 and the THO/TREX complex orchestrates <i>FLC</i> transcriptional output
Congyao Xu, Xiaofeng Fang, Tian-Cong Lu, Caroline Dean
Abstract
Significance RNA processing generally occurs as transcripts are being produced and the concomitant cotranscriptional processes are interconnected with chromatin regulation. These cotranscriptional mechanisms quantitatively influence transcriptional output. At the Arabidopsis gene FLC , repression involves alternative processing of FLC antisense transcripts linked to delivery of a local chromatin environment that determines FLC transcription initiation and elongation rate. Here, we show that AGO1, a factor known predominantly for its role in posttranscriptional gene silencing, is involved in this cotranscriptional repression mechanism. Conserved cotranscriptional regulators, the THO/TREX complex and NTC components of the activated spliceosome, physically associate with AGO1. Our analysis suggests that alternative interactions of cotranscriptional regulators with the RNA Pol II–spliceosome link RNA processing and chromatin modification to quantitatively regulate transcriptional output.