C. elegans Heterochromatin Factor SET-32 Plays an Essential Role in Transgenerational Establishment of Nuclear RNAi-Mediated Epigenetic Silencing.
Cell Rep
; 25(8): 2273-2284.e3, 2018 11 20.
Article
em En
| MEDLINE
| ID: mdl-30463021
ABSTRACT
The dynamic process by which nuclear RNAi engages a transcriptionally active target, before the repressive state is stably established, remains largely a mystery. Here, we found that the onset of exogenous dsRNA-induced nuclear RNAi in C. elegans is a transgenerational process, and it requires a putative histone methyltransferase (HMT), SET-32. By developing a CRISPR-based genetic approach, we found that silencing establishment at the endogenous targets of germline nuclear RNAi also requires SET-32. Although SET-32 and two H3K9 HMTs, MET-2 and SET-25, are dispensable for the maintenance of silencing, they do contribute to transcriptional repression in mutants that lack the germline nuclear Argonaute protein HRDE-1, suggesting a conditional role of heterochromatin in the maintenance phase. Our study indicates that (1) establishment and maintenance of siRNA-guided transcriptional repression are two distinct processes with different genetic requirements and (2) the rate-limiting step of the establishment phase is a transgenerational, chromatin-based process.
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MEDLINE
Assunto principal:
Heterocromatina
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Caenorhabditis elegans
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Proteínas de Caenorhabditis elegans
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Interferência de RNA
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Epigênese Genética
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Histona Metiltransferases
Limite:
Animals
Idioma:
En
Revista:
Cell Rep
Ano de publicação:
2018
Tipo de documento:
Article