Npl3 functions in mRNP assembly by recruitment of mRNP components to the transcription site and their transfer onto the mRNA

Assessing the function of the RNA-binding activity of RNA-binding proteins (RBPs) is challenging. Here, Keil et al. use a targeted XL-ms approach to identify RNA-binding sites in components of nuclear mRNPs in S. cerevisiae. The analysis of RNA-binding mutants of one selected example, the SR-like protein Npl3, uncovers two novel functions of Npl3, namely in the recruitment of mRNP components to transcribed protein-coding genes and their transfer onto the mRNA. This data set applies label-free protein quantification to assess protein abundancies in NPL3 or CBC2 affinity purification experiments from cellular lysates of NPL3-WT and NPL3-P196D/A197D double-mutant expressing cells.