Maelstrom Represses Canonical Polymerase II Transcription within Bi-directional piRNA Clusters in Drosophila melanogaster.
Mol Cell
; 73(2): 291-303.e6, 2019 01 17.
Article
em En
| MEDLINE
| ID: mdl-30527661
ABSTRACT
In Drosophila, 23-30 nt long PIWI-interacting RNAs (piRNAs) direct the protein Piwi to silence germline transposon transcription. Most germline piRNAs derive from dual-strand piRNA clusters, heterochromatic transposon graveyards that are transcribed from both genomic strands. These piRNA sources are marked by the heterochromatin protein 1 homolog Rhino (Rhi), which facilitates their promoter-independent transcription, suppresses splicing, and inhibits transcriptional termination. Here, we report that the protein Maelstrom (Mael) represses canonical, promoter-dependent transcription in dual-strand clusters, allowing Rhi to initiate piRNA precursor transcription. Mael also represses promoter-dependent transcription at sites outside clusters. At some loci, Mael repression requires the piRNA pathway, while at others, piRNAs play no role. We propose that by repressing canonical transcription of individual transposon mRNAs, Mael helps Rhi drive non-canonical transcription of piRNA precursors without generating mRNAs encoding transposon proteins.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transcrição Gênica
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RNA Polimerase II
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RNA Mensageiro
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Elementos de DNA Transponíveis
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RNA Guia de Cinetoplastídeos
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Proteínas de Drosophila
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RNA Interferente Pequeno
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Drosophila melanogaster
Limite:
Animals
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos