RNA quality control factors nucleate Clr4/SUV39H and trigger constitutive heterochromatin assembly.
Cell
; 187(13): 3262-3283.e23, 2024 Jun 20.
Article
em En
| MEDLINE
| ID: mdl-38815580
ABSTRACT
In eukaryotes, the Suv39 family of proteins tri-methylate lysine 9 of histone H3 (H3K9me) to form constitutive heterochromatin. However, how Suv39 proteins are nucleated at heterochromatin is not fully described. In the fission yeast, current models posit that Argonaute1-associated small RNAs (sRNAs) nucleate the sole H3K9 methyltransferase, Clr4/SUV39H, to centromeres. Here, we show that in the absence of all sRNAs and H3K9me, the Mtl1 and Red1 core (MTREC)/PAXT complex nucleates Clr4/SUV39H at a heterochromatic long noncoding RNA (lncRNA) at which the two H3K9 deacetylases, Sir2 and Clr3, also accumulate by distinct mechanisms. Iterative cycles of H3K9 deacetylation and methylation spread Clr4/SUV39H from the nucleation center in an sRNA-independent manner, generating a basal H3K9me state. This is acted upon by the RNAi machinery to augment and amplify the Clr4/H3K9me signal at centromeres to establish heterochromatin. Overall, our data reveal that lncRNAs and RNA quality control factors can nucleate heterochromatin and function as epigenetic silencers in eukaryotes.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Schizosaccharomyces
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Heterocromatina
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Histonas
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Histona-Lisina N-Metiltransferase
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Proteínas de Ciclo Celular
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Proteínas de Schizosaccharomyces pombe
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos