Pluto Bioinformatics

GSE92257: RNA fate determination through co-transcriptional methylation of newely synthesized transcripts

Bulk RNA sequencing

Using murine embryonic stem (mES) cells, here we show that two RNAi factors, Dgcr8 and the RNAseIII Drosha, physically associate with chromatin. We found that these known microRNA-processing factors associate with a subset of actively transcribed genes, as well as non-coding genes, including snoRNA, and lncRNA genes. Dgcr8 recruitment to chromatin was dependent on Methyltransferase-like 3 (Mettl3), which catalyzes N6-methyladenosine (m6A) of RNAs. Chemical inhibition of RNA polymerase II (RNAPII) disrupted the association of Dgcr8 and Mettl3 with chromatin, strongly suggesting RNA methylation and processing events occur co-transcriptionally. We also found that temperature stress causes a radical relocalization of Dgcr8 and Mettl3 to stress-induced genes including Hsp70. Genetic ablation of Dgcr8 or Mettl3 led to the accumulation of Hsp70 mRNA, elongation of its half-life, and increased protein levels only in cells subjected to acute heat stress. This indicates that acute heat-stress co-transcriptionally marks Hsp70 mRNAs by Mettl3 and Dgcr8 for subsequent RNA degradation to control the timing and magnitude of the heat shock response. SOURCE: Fabio Mohn (fabio.mohn@fmi.ch) - Buehler Lab Friedrich Miescher Institute for Biomedical Research