Analysis of alternative exon-dependent interactome remodelling reveals multitasking functions of gene regulatory factors (iCLIP-Seq)
Alternative splicing is fundamental for the expansion of biological complexity, particularly in the vertebrate nervous system. Increasing evidence indicates that developmental stage and tissue-dependent alternative exons often control protein-protein interactions, yet only a minor fraction of these events has been characterized at the protein level. Using affinity purification-mass spectrometry (AP-MS) we show that approximately 60% of analyzed neural-differential exons in proteins previously implicated in transcriptional regulation result in the gain or loss of interaction partners. Focusing on Chtop and Sap30bp, the neural exons in these proteins unexpectedly remodel interactions with partners associated with mRNA processing and trafficking. Sap30bp additionally controls RNA localization by regulating the splicing of <100 nt 'mini-introns' that contribute to the nuclear retention of transcripts. These activities of Chtop and Sap30bp are linked to programs of transcriptomic regulation associated with development of the nervous system. AP-MS is thus a powerful approach for elucidating multifaceted functions of proteins imparted by context-dependent alternative exons. Overall design: This dataset consists of 9 iCLIP-seq files associated with the manuscript "Analysis of alternative exon-dependent interactome remodelling reveals multitasking functions of gene regulatory factors" comparing RNA-pulldown between Chtop isoforms with or without exon 5 in Neuro2a cell lines. Each isoform (with or without exon 5) was profiled in triplicates and compared to three size-matched input control samples.