TRRAP is a central regulator of human multiciliated cell formation

J Cell Biol. 2018 Jun 4;217(6):1941-1955. doi: 10.1083/jcb.201706106. Epub 2018 Mar 27.

Abstract

The multiciliated cell (MCC) is an evolutionarily conserved cell type, which in vertebrates functions to promote directional fluid flow across epithelial tissues. In the conducting airway, MCCs are generated by basal stem/progenitor cells and act in concert with secretory cells to perform mucociliary clearance to expel pathogens from the lung. Studies in multiple systems, including Xenopus laevis epidermis, murine trachea, and zebrafish kidney, have uncovered a transcriptional network that regulates multiple steps of multiciliogenesis, ultimately leading to an MCC with hundreds of motile cilia extended from their apical surface, which beat in a coordinated fashion. Here, we used a pool-based short hairpin RNA screening approach and identified TRRAP, an essential component of multiple histone acetyltransferase complexes, as a central regulator of MCC formation. Using a combination of immunofluorescence, signaling pathway modulation, and genomic approaches, we show that (a) TRRAP acts downstream of the Notch2-mediated basal progenitor cell fate decision and upstream of Multicilin to control MCC differentiation; and (b) TRRAP binds to the promoters and regulates the expression of a network of genes involved in MCC differentiation and function, including several genes associated with human ciliopathies.

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism*
  • Cell Cycle Proteins / metabolism
  • Cell Line
  • Cell Lineage
  • Cilia / metabolism*
  • Epigenesis, Genetic
  • Epithelial Cells / metabolism
  • Forkhead Transcription Factors / metabolism
  • Gene Expression Regulation
  • Humans
  • Lung / cytology
  • Nuclear Proteins / metabolism*
  • RNA, Small Interfering / metabolism
  • Receptor, Notch2
  • Signal Transduction
  • Transcription Factors

Substances

  • Adaptor Proteins, Signal Transducing
  • Cell Cycle Proteins
  • FOXJ1 protein, human
  • Forkhead Transcription Factors
  • IDAS protein, human
  • Nuclear Proteins
  • RNA, Small Interfering
  • Receptor, Notch2
  • Transcription Factors
  • transformation-transcription domain-associated protein