%0 Journal Article
%T DNA Polymerase ¦Á (swi7) and the Flap Endonuclease Fen1 (rad2) Act Together in the S-Phase Alkylation Damage Response in S. pombe
%A Milana Koulintchenko
%A Sonya Vengrova
%A Trevor Eydmann
%A Prakash Arumugam
%A Jacob Z. Dalgaard
%J PLOS ONE
%D 2012
%I Public Library of Science (PLoS)
%R 10.1371/journal.pone.0047091
%X Polymerase ¦Á is an essential enzyme mainly mediating Okazaki fragment synthesis during lagging strand replication. A specific point mutation in Schizosaccharomyces pombe polymerase ¦Á named swi7-1, abolishes imprinting required for mating-type switching. Here we investigate whether this mutation confers any genome-wide defects. We show that the swi7-1 mutation renders cells hypersensitive to the DNA damaging agents methyl methansulfonate (MMS), hydroxyurea (HU) and UV and incapacitates activation of the intra-S checkpoint in response to DNA damage. In addition we show that, in the swi7-1 background, cells are characterized by an elevated level of repair foci and recombination, indicative of increased genetic instability. Furthermore, we detect novel Swi1-, -Swi3- and Pol ¦Á- dependent alkylation damage repair intermediates with mobility on 2D-gel that suggests presence of single-stranded regions. Genetic interaction studies showed that the flap endonuclease Fen1 works in the same pathway as Pol ¦Á in terms of alkylation damage response. Fen1 was also required for formation of alkylation- damage specific repair intermediates. We propose a model to explain how Pol ¦Á, Swi1, Swi3 and Fen1 might act together to detect and repair alkylation damage during S-phase.
%U http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0047091