Flap endonuclease overexpression drives genome instability and DNA damage hypersensitivity in a PCNA-dependent manner

Jordan R. Becker, David Gallo, Wendy Leung, Taylor Croissant, Yee Mon Thu, Hai Dang Nguyen, Timothy K. Starr, Grant W. Brown, Anja Katrin Bielinsky

Research output: Contribution to journalArticlepeer-review

9 Scopus citations

Abstract

Overexpression of the flap endonuclease FEN1 has been observed in a variety of cancer types and is a marker for poor prognosis. To better understand the cellular consequences of FEN1 overexpression we utilized a model of its Saccharomyces cerevisiae homolog, RAD27. In this system, we discovered that flap endonuclease overexpression impedes replication fork progression and leads to an accumulation of cells in mid-S phase. This was accompanied by increased phosphorylation of the checkpoint kinase Rad53 and histone H2A-S129. RAD27 overexpressing cells were hypersensitive to treatment with DNA damaging agents, and defective in ubiquitinating the replication clamp proliferating cell nuclear antigen (PCNA) at lysine 164. These effects were reversed when the interaction between overexpressed Rad27 and PCNA was ablated, suggesting that the observed phenotypes were linked to problems in DNA replication. RAD27 overexpressing cells also exhibited an unexpected dependence on the SUMO ligases SIZ1 and MMS21 for viability. Importantly, we found that overexpression of FEN1 in human cells also led to phosphorylation of CHK1, CHK2, RPA32 and histone H2AX, all markers of genome instability. Our data indicate that flap endonuclease overexpression is a driver of genome instability in yeast and human cells that impairs DNA replication in a manner dependent on its interaction with PCNA.

Original languageEnglish (US)
Pages (from-to)5634-5650
Number of pages17
JournalNucleic acids research
Volume46
Issue number11
DOIs
StatePublished - Jun 20 2018

Bibliographical note

Funding Information:
National Institutes of Health (NIH) [GM074917 to A.K.B.]; Canadian Cancer Society Research Institute, Impact Grant [702310 to G.W.B.]; Masonic Cancer Center at the University of Minnesota, Brainstorm Award (to A.K.B.); The Graduate School at the University of Minnesota Doctoral Dissertation Fellowship (to J.R.B.); Natural Sciences and Engineering Research Council of Canada PGS-D Award (to D.G.). Funding for open access charge: NIH [R01GM074917]. Conflict of interest statement. None declared.

Publisher Copyright:
© The Author(s) 2018. Published by Oxford University Press on behalf of Nucleic Acids Research.

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