Identification of an E3 ligase that targets the catalytic subunit of RNA Polymerase I upon transcription stress

Stephanie Pitts, Hester Liu, Adel Ibrahim, Amit Garg, Catarina Mendes Felgueira, Asma Begum, Wenjun Fan, Selina Teh, Jin Yih Low, Brittany Ford, David A. Schneider, Ronald Hay, Marikki Laiho

Research output: Contribution to journalArticleScientificpeer-review


RNA Polymerase I (Pol I) synthesizes rRNA, which is the first and rate-limiting step in ribosome biogenesis. Factors governing the stability of the polymerase complex are not known. Previous studies characterizing Pol I inhibitor BMH-21 revealed a transcriptional stress-dependent pathway for degradation of the largest subunit of Pol I, RPA194. To identify the E3 ligase(s) involved, we conducted a cell-based RNAi screen for ubiquitin pathway genes. We establish Skp–Cullin–F-box protein complex F-box protein FBXL14 as an E3 ligase for RPA194. We show that FBXL14 binds to RPA194 and mediates RPA194 ubiquitination and degradation in cancer cells treated with BMH-21. Mutation analysis in yeast identified lysines 1150, 1153, and 1156 on Rpa190 relevant for the protein degradation. These results reveal the regulated turnover of Pol I, showing that the stability of the catalytic subunit is controlled by the F-box protein FBXL14 in response to transcription stress.

Original languageEnglish
Article number102690
JournalJournal of Biological Chemistry
Issue number12
Publication statusPublished - Dec 2022
MoE publication typeA1 Journal article-refereed

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Fields of Science

  • cancer
  • proteasome
  • small molecule
  • transcription
  • ubiquitin
  • 3111 Biomedicine
  • 3122 Cancers

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