Proximity chemistries to study RNA biology at the subcellular scale

RNAs preferentially localize across virtually every subcellular compartment, from membrane-bound organelles, membrane-less condensates and even the cell surface, where they perform locale-specific functions in close coordination with RNA-binding proteins (RBPs) and other RNAs. Within the cell, proximity labeling strategies enable selective chemical tagging and covalent encoding of spatial information, converting molecular proximity into chemically tractable readouts for downstream multi-omic analyses. A growing suite of proximity chemistries targeted at RNA have yielded tools to dissect the local organization and interactions of RNAs with high spatiotemporal resolution within the native cellular milieu. Here, we review the recent expansion and emerging themes in proximity chemistries that enable spatially-resolved interrogation of RNA biology at subcellular resolution across the transcriptome.