Broad noncoding transcription suggests genome surveillance by RNA polymerase V
| Autor: | M Hafiz Rothi, Shriya Sethuraman, Alan P. Boyle, Masayuki Tsuzuki, Adriana N Coke, Andrzej T. Wierzbicki |
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| Rok vydání: | 2020 |
| Předmět: |
Transposable element
Genetics Small interfering RNA Genome RNA Untranslated Multidisciplinary RNA polymerase V Transcription Genetic Euchromatin Arabidopsis Proteins Base pair Arabidopsis DNA-Directed RNA Polymerases Biological Sciences Biology Non-coding RNA Models Biological Substrate Specificity Gene Expression Regulation Plant Transcription (biology) Multiprotein Complexes DNA Transposable Elements Gene Silencing |
| Zdroj: | Proc Natl Acad Sci U S A |
| ISSN: | 1091-6490 0027-8424 |
| Popis: | Eukaryotic genomes are pervasively transcribed, yet most transcribed sequences lack conservation or known biological functions. In Arabidopsis thaliana, RNA polymerase V (Pol V) produces noncoding transcripts, which base pair with small interfering RNA (siRNA) and allow specific establishment of RNA-directed DNA methylation (RdDM) on transposable elements. Here, we show that Pol V transcribes much more broadly than previously expected, including subsets of both heterochromatic and euchromatic regions. At already established RdDM targets, Pol V and siRNA work together to maintain silencing. In contrast, some euchromatic sequences do not give rise to siRNA but are covered by low levels of Pol V transcription, which is needed to establish RdDM de novo if a transposon is reactivated. We propose a model where Pol V surveils the genome to make it competent to silence newly activated or integrated transposons. This indicates that pervasive transcription of nonconserved sequences may serve an essential role in maintenance of genome integrity. |
| Databáze: | OpenAIRE |
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