Mi-2/NuRD complex protects stem cell progeny from mitogenic Notch signaling

Elife. 2019 Jan 29:8:e41637. doi: 10.7554/eLife.41637.

Abstract

To progress towards differentiation, progeny of stem cells need to extinguish expression of stem-cell maintenance genes. Failures in such mechanisms can drive tumorigenesis. In Drosophila neural stem cell (NSC) lineages, excessive Notch signalling results in supernumerary NSCs causing hyperplasia. However, onset of hyperplasia is considerably delayed implying there are mechanisms that resist the mitogenic signal. Monitoring the live expression of a Notch target gene, E(spl)mγ, revealed that normal attenuation is still initiated in the presence of excess Notch activity so that re-emergence of NSC properties occurs only in older progeny. Screening for factors responsible, we found that depletion of Mi-2/NuRD ATP remodeling complex dramatically enhanced Notch-induced hyperplasia. Under these conditions, E(spl)mγ was no longer extinguished in NSC progeny. We propose that Mi-2 is required for decommissioning stem-cell enhancers in their progeny, enabling the switch towards more differentiated fates and rendering them insensitive to mitogenic factors such as Notch.

Keywords: D. melanogaster; Notch; NuRD Complex; chromosomes; developmental biology; gene expression; stem cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / genetics*
  • Adenosine Triphosphatases / metabolism
  • Animals
  • Autoantigens / genetics*
  • Autoantigens / metabolism
  • Basic Helix-Loop-Helix Transcription Factors / genetics*
  • Basic Helix-Loop-Helix Transcription Factors / metabolism
  • Carcinogenesis / genetics
  • Carcinogenesis / metabolism
  • Carcinogenesis / pathology
  • Cell Differentiation
  • Cell Lineage / genetics
  • Cell Proliferation
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / growth & development
  • Drosophila melanogaster / metabolism
  • Gene Expression Regulation, Developmental
  • Humans
  • Hyperplasia / genetics*
  • Hyperplasia / metabolism
  • Hyperplasia / pathology
  • Models, Biological
  • Neural Stem Cells / cytology
  • Neural Stem Cells / metabolism*
  • Neurons / cytology
  • Neurons / metabolism
  • Protein Binding
  • Receptors, Notch / genetics*
  • Receptors, Notch / metabolism
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Signal Transduction

Substances

  • Autoantigens
  • Basic Helix-Loop-Helix Transcription Factors
  • Drosophila Proteins
  • E(spl)m7-HLH protein, Drosophila
  • Mi-2 protein, Drosophila
  • N protein, Drosophila
  • Receptors, Notch
  • Repressor Proteins
  • Adenosine Triphosphatases