Stabilization of G-quadruplex DNA structures in Schizosaccharomyces pombe causes single-strand DNA lesions and impedes DNA replication
Artikel i vetenskaplig tidskrift, 2020

G-quadruplex (G4) structures are stable non-canonical DNA structures that are implicated in the regulation of many cellular pathways. We show here that the G4-stabilizing compound PhenDC3 causes growth defects in Schizosaccharomyces pombe cells, especially during S-phase in synchronized cultures. By visualizing individual DNA molecules, we observed shorter DNA fragments of newly replicated DNA in the PhenDC3-treated cells, suggesting that PhenDC3 impedes replication fork progression. Furthermore, a novel single DNA molecule damage assay revealed increased single-strand DNA lesions in the PhenDC3-treated cells. Moreover, chromatin immunoprecipitation showed enrichment of the leading-strand DNA polymerase at sites of predicted G4 structures, suggesting that these structures impede DNA replication. We tested a subset of these sites and showed that they form G4 structures, that they stall DNA synthesis in vitro and that they can be resolved by the breast cancer-associated Pif1 family helicases. Our results thus suggest that G4 structures occur in S. pombe and that stabilized/unresolved G4 structures are obstacles for the replication machinery. The increased levels of DNA damage might further highlight the association of the human Pif1 helicase with familial breast cancer and the onset of other human diseases connected to unresolved G4 structures.

Författare

Ikenna Obi

Umeå universitet

Matilda Rentoft

Umeå universitet

Vandana Singh

Chalmers, Biologi och bioteknik, Kemisk biologi

Jan Jamroskovic

Umeå universitet

Karam Chand

Umeå universitet

E. Chorell

Umeå universitet

Fredrik Westerlund

Chalmers, Biologi och bioteknik, Kemisk biologi

Nasim Sabouri

Umeå universitet

Nucleic Acids Research

0305-1048 (ISSN) 1362-4962 (eISSN)

Vol. 48 19 10998-11015

Ämneskategorier

Biokemi och molekylärbiologi

Annan medicinsk grundvetenskap

Medicinsk bioteknologi (med inriktning mot cellbiologi (inklusive stamcellsbiologi), molekylärbiologi, mikrobiologi, biokemi eller biofarmaci)

Styrkeområden

Hälsa och teknik

DOI

10.1093/nar/gkaa820

PubMed

33045725

Mer information

Senast uppdaterat

2020-11-24