GSE70081
Chromatin immunoprecipitation sequencing of heterochromatin-associated proteins in Tetrahymena
In the ciliated protozoan Tetrahymena, de novo heterochromatin body formation is accompanied by programmed DNA elimination. Here, we show that the novel heterochromatin body component Jub1p promotes heterochromatin body formation and dephosphorylation of the Heterochromatin Protein 1 (HP1)-like protein Pdd1p. Through the identification and mutagenesis of the phosphorylated residues of Pdd1p, we demonstrate that Pdd1p dephosphorylation promotes the electrostatic interaction between Pdd1p and RNA in vitro and heterochromatin body formation in vivo. We therefore suggest that heterochromatin bodies are assembled by the Pdd1p-RNA interaction. Jub1p and Pdd1p dephosphorylation are required for heterochromatin body formation and DNA elimination but not for local heterochromatin assembly, indicating that heterochromatin body of itself plays an essential role in DNA elimination. Overall design: New macronuclei (MACs) of exconjugants were isolated from wild-type different mutant cells at 12 hpm, shared chromatin was immunoprecipitated and precipitated DNA was analyzed by high-throughput sequencing.