Alteration of RNA Splicing by Small-Molecule Inhibitors of the Interaction between NHP2L1 and U4

SLAS Discov. 2018 Feb;23(2):164-173. doi: 10.1177/2472555217735035. Epub 2017 Oct 6.


Splicing is an important eukaryotic mechanism for expanding the transcriptome and proteome, influencing a number of biological processes. Understanding its regulation and identifying small molecules that modulate this process remain a challenge. We developed an assay based on time-resolved fluorescence resonance energy transfer (TR-FRET) to detect the interaction between the protein NHP2L1 and U4 RNA, which are two key components of the spliceosome. We used this assay to identify small molecules that interfere with this interaction in a high-throughput screening (HTS) campaign. Topotecan and other camptothecin derivatives were among the top hits. We confirmed that topotecan disrupts the interaction between NHP2L1 and U4 by binding to U4 and inhibits RNA splicing. Our data reveal new functions of known drugs that could facilitate the development of therapeutic strategies to modify splicing and alter gene function.

Keywords: NHP2L1; Screening; U4; splicing.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Fluorescence Resonance Energy Transfer / methods
  • HEK293 Cells
  • High-Throughput Screening Assays / methods
  • Humans
  • RNA Splicing / drug effects*
  • RNA, Small Nuclear / metabolism*
  • Ribonucleoproteins, Small Nuclear / metabolism*
  • Small Molecule Libraries / pharmacology*
  • Spliceosomes / drug effects
  • Topotecan / pharmacology*


  • RNA, Small Nuclear
  • Ribonucleoproteins, Small Nuclear
  • Small Molecule Libraries
  • Snu13 protein, human
  • U4 small nuclear RNA
  • Topotecan