eLife (Aug 2017)

Major satellite repeat RNA stabilize heterochromatin retention of Suv39h enzymes by RNA-nucleosome association and RNA:DNA hybrid formation

  • Oscar Velazquez Camacho,
  • Carmen Galan,
  • Kalina Swist-Rosowska,
  • Reagan Ching,
  • Michael Gamalinda,
  • Fethullah Karabiber,
  • Inti De La Rosa-Velazquez,
  • Bettina Engist,
  • Birgit Koschorz,
  • Nicholas Shukeir,
  • Megumi Onishi-Seebacher,
  • Suzanne van de Nobelen,
  • Thomas Jenuwein

DOI
https://doi.org/10.7554/eLife.25293
Journal volume & issue
Vol. 6

Abstract

Read online

The Suv39h1 and Suv39h2 histone lysine methyltransferases are hallmark enzymes at mammalian heterochromatin. We show here that the mouse Suv39h2 enzyme differs from Suv39h1 by containing an N-terminal basic domain that facilitates retention at mitotic chromatin and provides an additional affinity for major satellite repeat RNA. To analyze an RNA-dependent interaction with chromatin, we purified native nucleosomes from mouse ES cells and detect that Suv39h1 and Suv39h2 exclusively associate with poly-nucleosomes. This association was attenuated upon RNaseH incubation and entirely lost upon RNaseA digestion of native chromatin. Major satellite repeat transcripts remain chromatin-associated and have a secondary structure that favors RNA:DNA hybrid formation. Together, these data reveal an RNA-mediated mechanism for the stable chromatin interaction of the Suv39h KMT and suggest a function for major satellite non-coding RNA in the organization of an RNA-nucleosome scaffold as the underlying structure of mouse heterochromatin.

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