APLF and long non-coding RNA NIHCOLE promote stable DNA synapsis in non-homologous end joining

The synapsis of DNA ends is a critical step for the repair of double-strand breaks by non-homologous end joining (NHEJ). This is performed by a multicomponent protein complex assembled around Ku70-Ku80 heterodimers and regulated by accessory factors, including long non-coding RNAs, through poorly un...

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Detalles Bibliográficos
Autores: Bragança, Sara de, Aicart-Ramos, Clara, Arribas-Bosacoma, Raquel, Rivera-Calzada, Ángel, Unfried, Juan P., Prats-Mari, Laura, Marin-Baquero, Mikel, Fortes, Puri, Llorca, Óscar, Moreno-Herrero, Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/286401
Acceso en línea:http://hdl.handle.net/10261/286401
Access Level:acceso abierto
Palabra clave:Ku70-Ku80
APLF
lncRNA
Single-molecule
Non-homologous end joining
NHEJ
Xrcc4
DNA ligase IV
XLF
Magnetic tweezers
Descripción
Sumario:The synapsis of DNA ends is a critical step for the repair of double-strand breaks by non-homologous end joining (NHEJ). This is performed by a multicomponent protein complex assembled around Ku70-Ku80 heterodimers and regulated by accessory factors, including long non-coding RNAs, through poorly understood mechanisms. Here, we use magnetic tweezers to investigate the contributions of core NHEJ proteins and APLF and lncRNA NIHCOLE to DNA synapsis. APLF stabilizes DNA end bridging and, together with Ku70-Ku80, establishes a minimal complex that supports DNA synapsis for several minutes under piconewton forces. We find the C-terminal acidic region of APLF to be critical for bridging. NIHCOLE increases the dwell time of the synapses by Ku70-Ku80 and APLF. This effect is further enhanced by a small and structured RNA domain within NIHCOLE. We propose a model where Ku70-Ku80 can simultaneously bind DNA, APLF, and structured RNAs to promote the stable joining of DNA ends.