Taz1-Shelterin promotes facultative heterochromatin assembly at chromosome-internal sites containing late replication origins [Taz1]

ABSTRACT: Occupancy profiling of Shelterin components in fission yeast. Facultative heterochromatin regulates gene expression, but its assembly is poorly understood. Previously, we identified facultative heterochromatin islands in the fission yeast genome and found that RNA elimination machinery promotes island assembly at meiotic genes. Here, we report that Taz1, a component of the telomere protection complex Shelterin, is required to assemble heterochromatin islands at regions corresponding to late replication origins that are sites of double-strand break formation during meiosis. The loss of Taz1 and other Shelterin subunits, including Ccq1 that interacts with Clr4/Suv39h, abolishes heterochromatin at late origins and causes defective silencing of associated genes. Moreover, the late origin regulator Rif1 affects heterochromatin at Taz1-dependent islands and subtelomeric regions. We uncover a connection between heterochromatin and replication control, and show that heterochromatin factors affect timing of replication. These analyses implicate Shelterin in facultative heterochromatin assembly at late origins, which has important implications for the maintenance of genome stability and gene regulation. Whole cell extract DNA and DNA recovered from Taz1 or Rif1-immunoprecipitated chromatin of fission yeast were random-prime PCR amplified and labeled with Cy3 (whole cell extract DNA) or with Cy5 (IP DNA) and analyzed using custom 60mer Agilent array that tiles Schizosaccharomyces pombe genome in 300bp intervals alternately on both strands.

ORGANISM(S): Schizosaccharomyces pombe

SUBMITTER: Shiv Grewal 

PROVIDER: E-GEOD-78822 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress