PT  - JOURNAL ARTICLE
AU  - Brunno R. Levone
AU  - Silvia C. Lenzken
AU  - Marco Antonaci
AU  - Andreas Maiser
AU  - Alexander Rapp
AU  - Francesca Conte
AU  - Stefan Reber
AU  - Antonella E. Ronchi
AU  - Oliver Mühlemann
AU  - Heinrich Leonhardt
AU  - M. Cristina Cardoso
AU  - Marc-David Ruepp
AU  - Silvia M.L. Barabino
TI  - FUS-dependent liquid-liquid phase separation is an early event in double-strand break repair
AID  - 10.1101/798884
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 798884
4099  - http://biorxiv.org/content/early/2020/08/24/798884.short
4100  - http://biorxiv.org/content/early/2020/08/24/798884.full
AB  - RNA-binding proteins (RBPs) are emerging as important effectors of the cellular DNA damage response (DDR). The RBP FUS is implicated in RNA metabolism and DNA repair, and it undergoes reversible liquid-liquid phase separation (LLPS) in vitro. Here, we demonstrate that FUS-dependent LLPS is necessary for the initiation of the DDR. Using laser microirradiation in FUS-knockout cells, we show that FUS is required for the recruitment to DNA damage sites of the DDR factors KU80, NBS1, 53BP1, and of SFPQ, another RBP implicated in the DDR. The relocation of KU80, NBS1, and SFPQ is similarly impaired by LLPS inhibitors, or LLPS-deficient FUS variants. We also show that LLPS is necessary for efficient γH2AX foci formation. Finally, using super-resolution structured illumination microscopy, we demonstrate that the absence of FUS impairs the proper arrangement of γH2AX nano-foci into higher-order clusters. These findings demonstrate the early requirement for FUS-dependent LLPS in the activation of the DDR and the proper assembly of DSBs repair complexes.Competing Interest StatementThe authors have declared no competing interest.