Dna2 is a DNA helicase-endonuclease mediating DSB resection and Okazaki fragment processing. Dna2 ablation is lethal and rescued by inactivation of Pif1, a helicase assisting Okazaki fragment maturation, Pol32, a DNA polymerase δ subunit, and Rad9, a DNA damage response (DDR) factor. Dna2 counteracts fork reversal and promotes fork restart. Here we show that Dna2 depletion generates lethal DNA structures activating the DDR. While PIF1 deletion rescues the lethality of Dna2 depletion, RAD9 ablation relieves the first cell cycle arrest causing genotoxicity after few cell divisions. Slow fork speed attenuates DDR in Dna2 deprived cells. Electron microscopy shows that Dna2-ablated cells accumulate long ssDNA flaps behind the forks through Pif1 and fork speed. We suggest that Dna2 offsets the strand displacement activity mediated by the lagging strand polymerase and Pif1, processing long ssDNA flaps to prevent DDR activation. We propose that this Dna2 function has been hijacked by Break Induced Replication in DSB processing.
Dna2 processes behind the fork long ssDNA flaps generated by Pif1 and replication-dependent strand displacement / S.E. Rossi, M. Foiani, M. Giannattasio. - In: NATURE COMMUNICATIONS. - ISSN 2041-1723. - 9(2018 Nov 16), pp. 4830.1-4830.11.
|Titolo:||Dna2 processes behind the fork long ssDNA flaps generated by Pif1 and replication-dependent strand displacement|
ROSSI, SILVIA EMMA (Primo)
FOIANI, MARCO (Secondo) (Corresponding)
GIANNATTASIO, MICHELE (Ultimo) (Corresponding)
|Parole Chiave:||cell cycle checkpoints; cell cycle proteins; DNA breaks, single-stranded; DNA helicases; DNA, single-stranded; DNA-directed DNA polymerase; genes, lethal; saccharomyces cerevisiae; saccharomyces cerevisiae proteins; DNA replication; gene expression regulation, fungal; recombinational DNA repair|
|Settore Scientifico Disciplinare:||Settore BIO/11 - Biologia Molecolare|
|Data di pubblicazione:||16-nov-2018|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1038/s41467-018-07378-5|
|Appare nelle tipologie:||01 - Articolo su periodico|