Asymmetrical nucleosomal DNA signatures regulate transcriptional directionality.

[EN]Despite the symmetrical structure of nucleosomes, in vitro studies have shown that transcription proceeds with different efficiency depending on the orientation of the DNA sequence around them. However, it is unclear whether this functional asymmetry is present in vivo and whether it could regul...

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Bibliographic Details
Authors: García Martínez, Alicia, Durán, Laura, Sánchez, Mar, González, Sara, Santamaría Vicente, Rodrigo, Antequera Márquez, Francisco
Format: article
Status:Published version
Publication Date:2023
Country:España
Institution:Universidad de Salamanca (USAL)
Repository:GREDOS. Repositorio Institucional de la Universidad de Salamanca
OAI Identifier:oai:gredos.usal.es:10366/154334
Online Access:http://hdl.handle.net/10366/154334
Access Level:Open access
Keyword:Nucleosomes
Transcription
Transcription directionality
Transcriptomics
Genomics
DNA Sequence analysis
DNA Nucleosome signature
Description
Summary:[EN]Despite the symmetrical structure of nucleosomes, in vitro studies have shown that transcription proceeds with different efficiency depending on the orientation of the DNA sequence around them. However, it is unclear whether this functional asymmetry is present in vivo and whether it could regulate transcriptional directionality. Here, we report that the proximal and distal halves of nucleosomal DNA contribute differentially to nucleosome stability in the genome. In +1 nucleosomes, this asymmetry facilitates or hinders transcription depending on the orientation of its underlying DNA, and this difference is associated with an asymmetrical interaction between DNA and histones. These properties are encoded in the DNA signature of +1 nucleosomes, since its incorporation in the two orientations into downstream nucleosomes renders them asymmetrically accessible to MNase and inverts the balance between sense and antisense transcription. Altogether, our results show that nucleosomal DNA endows nucleosomes with asymmetrical properties that modulate the directionality of transcription.