RNA helicase DDX21 mediates nucleotide stress responses in neural crest and melanoma cells

• Published in: Nature cell biology Vol. 22; no. 4; pp. 372 - 379
• Main Authors: Santoriello, Cristina, Sporrij, Audrey, Yang, Song, Flynn, Ryan A., Henriques, Telmo, Dorjsuren, Bilguujin, Custo Greig, Eugenia, McCall, Wyatt, Stanhope, Meredith E., Fazio, Maurizio, Superdock, Michael, Lichtig, Asher, Adatto, Isaac, Abraham, Brian J., Kalocsay, Marian, Jurynec, Michael, Zhou, Yi, Adelman, Karen, Calo, Eliezer, Zon, Leonard I.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.04.2020; Nature Publishing Group
• Subjects: 631/208; 631/80; 64/116; 82; 82/58; Animals; Biomedical and Life Sciences; Cancer cells; Cancer Research; Cell Biology; Cell Line, Tumor; Cellular stress response; Chromatin; Danio rerio; DEAD-box RNA Helicases - genetics; DEAD-box RNA Helicases - metabolism; Depletion; Development and progression; Developmental Biology; Dihydroorotate Dehydrogenase; DNA helicase; Elongation; Embryo, Nonmammalian; Embryos; Gene expression; Gene Expression Regulation, Developmental; Genetic aspects; Genetic transcription; Health aspects; Helicases; Humans; Leflunomide; Leflunomide - pharmacology; Letter; Life Sciences; Melanocytes - drug effects; Melanocytes - metabolism; Melanocytes - pathology; Melanoma; Mutants; Neural crest; Neural Crest - drug effects; Neural Crest - growth & development; Neural Crest - metabolism; Nucleotides; Occupancy; Oxidoreductases Acting on CH-CH Group Donors - genetics; Oxidoreductases Acting on CH-CH Group Donors - metabolism; Phosphoproteins - genetics; Phosphoproteins - metabolism; Physiological aspects; Progesterone; Progesterone - metabolism; Protein Binding; Protein research; Proteomics; Receptors; Receptors, Progesterone - genetics; Receptors, Progesterone - metabolism; Restoration; Ribonucleic acid; RNA; RNA helicase; Signal Transduction; Stem Cells; Stress, Physiological - genetics; Supplements; Transcription elongation; Transcription Elongation, Genetic; Transcription Factors - genetics; Transcription Factors - metabolism; Zebrafish; Zebrafish - embryology; Zebrafish - genetics; Zebrafish - metabolism; Zebrafish Proteins - genetics; Zebrafish Proteins - metabolism; United States
• ISSN: 1465-7392; 1476-4679
• DOI: 10.1038/s41556-020-0493-0

The availability of nucleotides has a direct impact on transcription. The inhibition of dihydroorotate dehydrogenase (DHODH) with leflunomide impacts nucleotide pools by reducing pyrimidine levels. Leflunomide abrogates the effective transcription elongation of genes required for neural crest development and melanoma growth in vivo 1 . To define the mechanism of action, we undertook an in vivo chemical suppressor screen for restoration of neural crest after leflunomide treatment. Surprisingly, we found that alterations in progesterone and progesterone receptor (Pgr) signalling strongly suppressed leflunomide-mediated neural crest effects in zebrafish. In addition, progesterone bypasses the transcriptional elongation block resulting from Paf complex deficiency, rescuing neural crest defects in ctr9 morphant and paf1 ( aln z24 ) mutant embryos. Using proteomics, we found that Pgr binds the RNA helicase protein Ddx21. ddx21 -deficient zebrafish show resistance to leflunomide-induced stress. At a molecular level, nucleotide depletion reduced the chromatin occupancy of DDX21 in human A375 melanoma cells. Nucleotide supplementation reversed the gene expression signature and DDX21 occupancy changes prompted by leflunomide. Together, our results show that DDX21 acts as a sensor and mediator of transcription during nucleotide stress. Santoriello, Sporrij et al. show that the progesterone receptor associates with RNA helicase DDX21 during nucleotide depletion, promotes its binding on chromatin and rescues efficient transcription in melanoma cells.