TPR Knockdown Frac-Seq

How splicing regulates the nuclear export of mRNAs has been a source of much debate. While splicing has been shown to enhance nuclear export, it has remained unclear whether mRNAs generated from intronless genes use specific machinery to promote their export. Here we investigate the role of the major nuclear pore basket protein, TPR, in regulating mRNA and lncRNA nuclear export. We provide evidence that TPR is required for the nuclear export of mRNAs and lncRNAs that are generated from intronless or intron-poor genes. In contrast, TPR is not required for the nuclear retention of mRNAs that have retained introns, or unused 5' splice site motifs. In summary, our study provides one of the first examples of a factor that is specifically required for the nuclear export of intronless mRNAs. Overall design: Examination of nucleocytoplasmic transcript distribution upon TPR knockdown in U2OS cells