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bioRxiv · 10.1101/305169

Biphasic recruitment of TRF2 to DNA damage sites promotes non-sister chromatid homologous recombination repair

Kong, X.·Cruz, G.·Trinh, S.·Zhu, X.-D.·Berns, M.·Yokomori, K.
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Abstract

TRF2 binds to telomeric repeats and is critical for telomere integrity. Evidence suggests that it also localizes to non-telomeric DNA damage sites. However, this recruitment appears to be precarious and functionally controversial. We find that TRF2 recruitment to damage sites occurs by a two-step mechanism: the initial rapid recruitment (phase I) and stable and prolonged association with damage sites (phase II). Phase I is poly(ADP-ribose) polymerase (PARP)-dependent and requires the N-terminal basic domain. The phase II recruitment requires the C-terminal MYB/SANT domain and the iDDR region in the hinge domain, which is mediated by the MRE11 complex and is stimulated by hTERT. PARP-dependent recruitment of intrinsically disordered proteins contributes to transient displacement of TRF2 that separates two phases. TRF2 binds to the I-PpoI-induced DNA double-strand break sites, which is enhanced by the presence of complex damage and is dependent on PARP and the MRE11 complex. TRF2 depletion affects non-sister chromatid homologous recombination (HR) repair, but not HR between sister chromatids or non-homologous endjoining pathways. Our results demonstrate a unique recruitment mechanism and function of TRF2 at non-telomeric DNA damage sites.\n\nSummary StatementTRF2 is recruited to DNA double-strand break damage sites by a two-step mechanism and functions in non-sister chromatid homologous recombination repair

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Kong, X., Cruz, G., Trinh, S., Zhu, X.-D., Berns, M., Yokomori, K.. 2018-04-20. Biphasic recruitment of TRF2 to DNA damage sites promotes non-sister chromatid homologous recombination repair. https://doi.org/10.1101/305169

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