Records of RNA localization through covalent tagging

RNA movements and localization pervade biology, from embryonic development to disease. To identify RNAs at specific subcellular locations, we anchored a uridine-adding enzyme at those sites, which then marked RNAs in its vicinity with 3’ terminal uridines. RNAs were tagged independent of their translation status, and included not only mRNAs, but also ncRNAs and ncRNA processing intermediates. A battery of RNAs, including the stress sensor, , were tagged at both ER and mitochondria, and reveal RNAs whose dual localization is conserved from yeast to human cells.