BioProject

In S. pombe, transcripts derived from the pericentromeric dg and dh repeats promote heterochromatin formation via RNAi as well as an RNAi-independent mechanism involving the RNAPII-associated RNA-binding protein Seb1 and RNA processing activities. More...

In S. pombe, transcripts derived from the pericentromeric dg and dh repeats promote heterochromatin formation via RNAi as well as an RNAi-independent mechanism involving the RNAPII-associated RNA-binding protein Seb1 and RNA processing activities. We show that Seb1 promotes long-lived RNAPII pauses at pericentromeric repeat regions and 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. Overall design: ChIP-Seq was conducted on 70 samples of various strain backgrounds to visualize heterochromatin assembly and RNApolII denisites across the S. pombe genome. Less...