Human THO–Sin3A interaction reveals new mechanisms to prevent R-loops that cause genome instability

R-loops, formed by co-transcriptional DNA–RNA hybrids and a displaced DNA single strand (ssDNA), fulfill certain positive regulatory roles but are also a source of genomic instability. One key cellular mechanism to prevent R-loop accumulation centers on the conserved THO/TREX complex, an RNA-binding...

Descripción completa

Detalles Bibliográficos
Autores: Salas Armenteros, Irene, Pérez Calero, Carmen, Bayona Feliu, Aleix, Tumini, Emanuela, Luna Varo, Rosa María, Aguilera López, Andrés
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2017
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/87419
Acceso en línea:https://hdl.handle.net/11441/87419
https://doi.org/10.15252/embj.201797208
Access Level:acceso abierto
Palabra clave:DNA–RNA hybrids
Genome instability
Histone acetylation
Sin3A deacetylase
THO/TREX
Descripción
Sumario:R-loops, formed by co-transcriptional DNA–RNA hybrids and a displaced DNA single strand (ssDNA), fulfill certain positive regulatory roles but are also a source of genomic instability. One key cellular mechanism to prevent R-loop accumulation centers on the conserved THO/TREX complex, an RNA-binding factor involved in transcription elongation and RNA export that contributes to messenger ribonucleoprotein (mRNP) assembly, but whose precise function is still unclear. To understand how THO restrains harmful R-loops, we searched for new THO-interacting factors. We found that human THO interacts with the Sin3A histone deacetylase complex to suppress co-transcriptional R-loops, DNA damage, and replication impairment. Functional analyses show that histone hypo-acetylation prevents accumulation of harmful R-loops and RNA-mediated genomic instability. Diminished histone deacetylase activity in THO- and Sin3A-depleted cell lines correlates with increased R-loop formation, genomic instability, and replication fork stalling. Our study thus uncovers physical and functional crosstalk between RNA-binding factors and chromatin modifiers with a major role in preventing R-loop formation and RNA-mediated genome instability.