Identification of RNA–Protein Interactions Through In Vitro RNA Pull-Down Assays

Recent advances in next-generation sequencing have revealed that majority of the human genome is transcribed into long and short RNA (ncRNA) transcripts. Many ncRNAs function by interacting with proteins and forming regulatory complexes. RNA-protein interactions are vital in controlling core cellular processes like transcription and translation. Therefore identifying proteins that interact with ncRNAs is central to deciphering ncRNA functions. Here we describe an RNA-protein pull-down assay, which enables the identification of proteins that interact with an RNA under study. As an example we describe pull-down of proteins interacting with ncRNA XIST, which assists in the recruitment of the polycomb-repressive complex-2 (PRC2) and drives X-chromosomal inactivation.