Clr4^SUV39H1 ubiquitination and non-coding RNA mediate transcriptional silencing of heterochromatin via Swi6 phase separation.

ABSTRACT: Transcriptional silencing by RNAi paradoxically relies on transcription, but how the transition from transcription to silencing is achieved has remained unclear. The Cryptic Loci Regulator complex (CLRC) in Schizosaccharomyces pombe is a cullin-ring E3 ligase required for silencing that is recruited by RNAi. We found that the E2 ubiquitin conjugating enzyme Ubc4 interacts with CLRC and mono-ubiquitinates the histone H3K9 methyltransferase Clr4^SUV39H1, promoting the transition from co-transcriptional gene silencing (H3K9me2) to transcriptional gene silencing (H3K9me3). Ubiquitination of Clr4 occurs in an intrinsically disordered region (Clr4^IDR), which undergoes liquid droplet formation in vitro, along with Swi6^HP1 the effector of transcriptional gene silenc

SUBMITTER: Kim HS 

PROVIDER: S-EPMC11526040 | biostudies-literature | 2024 Oct

REPOSITORIES: biostudies-literature