Regulation of ectopic heterochromatin-mediated epigenetic diversification by the JmjC family protein Epe1

by Masato Sorida, Takahiro Hirauchi, Hiroaki Ishizaki, Wataru Kaito, Atsushi Shimada, Chie Mori, Yuji Chikashige, Yasushi Hiraoka, Yutaka Suzuki, Yasuyuki Ohkawa, Hiroaki Kato, Shinya Takahata, Yota Murakami

H3K9 methylation (H3K9me) is a conserved marker of heterochromatin, a transcriptionally silent chromatin structure. Knowledge of the mechanisms for regulating heterochromatin distribution is limited. The fission yeast JmjC domain-containing protein Epe1 localizes to heterochromatin mainly through its interaction with Swi6, a homologue of heterochromatin protein 1 (HP1), and directs JmjC-mediated H3K9me demethylationin vivo. Here, we found that loss ofepe1 (epe1Δ) induced a red-white variegated phenotype in a red-pigment accumulation background that generated uniform red colonies. Analysis of isolated red and white colonies revealed that silencing of genes involved in pigment accumulation by stochastic ectopic heterochromatin formation led to white colony formation. In addition, genome-wide analysis of red- and white-isolated clones revealed thatepe1Δ resulted in a heterogeneous heterochromatin distribution among clones. We found that Epe1 had an N-terminal domain distinct from its JmjC domain, which activated transcription in both fission and budding yeasts. The N-terminal transcriptional activation (NTA) domain was involved in suppression of ectopic heterochromatin-mediated red-white variegation. We introduced a single copy of Epe1 intoepe1Δ clones harboring ectopic ...

Source: PLoS Genetics - June 16, 2019 Category: Genetics & Stem Cells Authors: Masato Sorida Source Type: research