The Upstream Sequence Transcription Complex dictates nucleosome positioning and promoter accessibility at piRNA genes in the C. elegans germ line.
PLoS Genet
; 20(7): e1011345, 2024 Jul.
Article
em En
| MEDLINE
| ID: mdl-38985845
ABSTRACT
The piRNA pathway is a conserved germline-specific small RNA pathway that ensures genomic integrity and continued fertility. In C. elegans and other nematodes, Type-I piRNAs are expressed from >10,000 independently transcribed genes clustered within two discrete domains of 1.5 and 3.5 MB on Chromosome IV. Clustering of piRNA genes contributes to their germline-specific expression, but the underlying mechanisms are unclear. We analyze isolated germ nuclei to demonstrate that the piRNA genomic domains are located in a heterochromatin-like environment. USTC (Upstream Sequence Transcription Complex) promotes strong association of nucleosomes throughout piRNA clusters, yet organizes the local nucleosome environment to direct the exposure of individual piRNA genes. Localization of USTC to the piRNA domains depends upon the ATPase chromatin remodeler ISW-1, which maintains high nucleosome density across piRNA clusters and ongoing production of piRNA precursors. Overall, this work provides insight into how chromatin states coordinate transcriptional regulation over large genomic domains, with implications for global genome organization.
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Base de dados:
MEDLINE
Assunto principal:
Nucleossomos
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Regiões Promotoras Genéticas
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Caenorhabditis elegans
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Proteínas de Caenorhabditis elegans
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RNA Interferente Pequeno
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Células Germinativas
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article