WDR5, BRCA1, and BARD1 Co-regulate the DNA Damage Response and Modulate the Mesenchymal-to-Epithelial Transition during Early Reprogramming

Stem Cell Reports. 2019 Apr 9;12(4):743-756. doi: 10.1016/j.stemcr.2019.02.006. Epub 2019 Mar 14.


Differentiated cells are epigenetically stable, but can be reprogrammed to pluripotency by expression of the OSKM transcription factors. Despite significant effort, relatively little is known about the cellular requirements for reprogramming and how they affect the properties of induced pluripotent stem cells. We have performed high-content screening with small interfering RNAs targeting 300 chromatin-associated factors and extracted colony-level quantitative features. This revealed five morphological phenotypes in early reprogramming, including one displaying large round colonies exhibiting an early block of reprogramming. Using RNA sequencing, we identified transcriptional changes associated with these phenotypes. Furthermore, double knockdown epistasis experiments revealed that BRCA1, BARD1, and WDR5 functionally interact and are required for the DNA damage response. In addition, the mesenchymal-to-epithelial transition is affected in Brca1, Bard1, and Wdr5 knockdowns. Our data provide a resource of chromatin-associated factors in early reprogramming and underline colony morphology as an important high-dimensional readout for reprogramming quality.

Keywords: BARD1; BRCA1; DNA damage repair; WDR5; chromatin factors; functional interactions; iPSCs; mesenchymal-to-epithelial transition; reprogramming.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • BRCA1 Protein / genetics*
  • BRCA1 Protein / metabolism
  • Cellular Reprogramming / genetics*
  • Chromatin / genetics
  • Chromatin / metabolism
  • DNA Damage*
  • DNA Repair
  • Epithelial-Mesenchymal Transition / genetics*
  • Gene Expression Profiling
  • Humans
  • Intracellular Signaling Peptides and Proteins / genetics*
  • Intracellular Signaling Peptides and Proteins / metabolism
  • Mice
  • Phenotype
  • Signal Transduction
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Tumor Suppressor Proteins / genetics*
  • Tumor Suppressor Proteins / metabolism
  • Ubiquitin-Protein Ligases / genetics*
  • Ubiquitin-Protein Ligases / metabolism


  • BRCA1 Protein
  • BRCA1 protein, human
  • Chromatin
  • Intracellular Signaling Peptides and Proteins
  • Transcription Factors
  • Tumor Suppressor Proteins
  • WDR5 protein, human
  • BARD1 protein, human
  • Ubiquitin-Protein Ligases