Polymerase pausing induced by sequence-specific RNA-binding protein drives heterochromatin assembly

Genes Dev. 2018 Jul 1;32(13-14):953-964. doi: 10.1101/gad.310136.117.


In Schizosaccharomyces pombe, transcripts derived from the pericentromeric dg and dh repeats promote heterochromatin formation via RNAi as well as an RNAi-independent mechanism involving the RNA polymerase II (RNAPII)-associated RNA-binding protein Seb1 and RNA processing activities. We show that Seb1 promotes long-lived RNAPII pauses at pericentromeric repeat regions and that their presence correlates with the heterochromatin-triggering activities of the corresponding dg and dh DNA fragments. Globally increasing RNAPII stalling by other means induces the formation of novel large ectopic heterochromatin domains. Such ectopic heterochromatin occurs even in cells lacking RNAi. These results uncover Seb1-mediated polymerase stalling as a signal necessary for heterochromatin nucleation.

Keywords: Seb1; centromere; heterochromatin; polymerase pausing.

Publication types

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

MeSH terms

  • Chromatin Assembly and Disassembly / genetics*
  • Heterochromatin* / genetics
  • Heterochromatin* / metabolism
  • Microsatellite Repeats / genetics
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • RNA Interference
  • RNA Polymerase II / genetics*
  • RNA Polymerase II / metabolism
  • RNA-Binding Proteins / genetics
  • RNA-Binding Proteins / metabolism*
  • Schizosaccharomyces pombe Proteins / genetics
  • Schizosaccharomyces pombe Proteins / metabolism*
  • Schizosaccharomyces* / enzymology
  • Schizosaccharomyces* / genetics


  • Heterochromatin
  • Nuclear Proteins
  • RNA-Binding Proteins
  • Schizosaccharomyces pombe Proteins
  • Seb1 protein, S pombe
  • RNA Polymerase II