Macrohistone Variants Preserve Cell Identity by Preventing the Gain of H3K4me2 during Reprogramming to Pluripotency

María J. Barrero, Borja Sese, Bernd Kuebler, Josipa Bilic, Stephanie Boue, Mercè Martí, Juan Carlos Izpisua Belmonte*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

52 Scopus citations

Abstract

Transcription-factor-induced reprogramming of somatic cells to pluripotency is a very inefficient process, probably due to the existence of important epigenetic barriers that are imposed during differentiation and that contribute to preserving cell identity. In an effort to decipher the molecular nature of these barriers, we followed a genome-wide approach, in which we identified macrohistone variants (macroH2A) as highly expressed in human somatic cells but downregulated after reprogramming to pluripotency, as well as strongly induced during differentiation. Knockdown of macrohistone variants in human keratinocytes increased the efficiency of reprogramming to pluripotency, whereas overexpression had opposite effects. Genome-wide occupancy profiles show that in human keratinocytes, macroH2A.1 preferentially occupies genes that are expressed at low levels and are marked with H3K27me3, including pluripotency-related genes and bivalent developmental regulators. The presence of macroH2A.1 at these genes prevents the regain of H3K4me2 during reprogramming, imposing an additional layer of repression that preserves cell identity.

Original languageEnglish (US)
Pages (from-to)1005-1011
Number of pages7
JournalCell Reports
Volume3
Issue number4
DOIs
StatePublished - Apr 25 2013

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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