Binding of HMGN proteins to cell specific enhancers stabilizes cell identity

Nat Commun. 2018 Dec 7;9(1):5240. doi: 10.1038/s41467-018-07687-9.

Abstract

The dynamic nature of the chromatin epigenetic landscape plays a key role in the establishment and maintenance of cell identity, yet the factors that affect the dynamics of the epigenome are not fully known. Here we find that the ubiquitous nucleosome binding proteins HMGN1 and HMGN2 preferentially colocalize with epigenetic marks of active chromatin, and with cell-type specific enhancers. Loss of HMGNs enhances the rate of OSKM induced reprogramming of mouse embryonic fibroblasts (MEFs) into induced pluripotent stem cells (iPSCs), and the ASCL1 induced conversion of fibroblast into neurons. During transcription factor induced reprogramming to pluripotency, loss of HMGNs accelerates the erasure of the MEF-specific epigenetic landscape and the establishment of an iPSCs-specific chromatin landscape, without affecting the pluripotency potential and the differentiation potential of the reprogrammed cells. Thus, HMGN proteins modulate the plasticity of the chromatin epigenetic landscape thereby stabilizing, rather than determining cell identity.

Publication types

  • Research Support, N.I.H., Intramural

MeSH terms

  • Animals
  • Cell Differentiation / genetics
  • Cell Membrane / metabolism*
  • Cells, Cultured
  • Cellular Reprogramming / genetics
  • Chromatin / genetics
  • Chromatin / metabolism
  • Embryo, Mammalian / cytology
  • Epigenesis, Genetic
  • Fibroblasts / cytology
  • Fibroblasts / metabolism*
  • HEK293 Cells
  • HMGN1 Protein / genetics
  • HMGN1 Protein / metabolism*
  • HMGN2 Protein / genetics
  • HMGN2 Protein / metabolism*
  • Humans
  • Induced Pluripotent Stem Cells / metabolism
  • Male
  • Mice, Knockout
  • Mice, Nude
  • Protein Binding

Substances

  • Chromatin
  • HMGN1 Protein
  • HMGN2 Protein