Proximity-CLIP Provides a Snapshot of Protein-Occupied RNA Elements at Subcellular Resolution and Transcriptome-Wide Scale.

The distribution of messenger RNAs (mRNAs) to specific subcellular locations has been studied for the past two decades. Technically, studies of RNA localization are lagging those related to protein localization. Here we provide a detailed protocol for Proximity-CLIP, a method recently developed by our group, that combines proximity biotinylation of proteins with photoactivatable ribonucleoside-enhanced protein-RNA cross-linking to simultaneously profile the proteome including RNA-binding proteins (RBPs) and the RBP-bound transcriptome in any given subcellular compartment. The approach is fractionation independent and also enables studying localized RNA-processing intermediates, as well as the identification of regulatory cis-acting elements on RNAs occupied by proteins in a cellular compartment-specific manner.