Fersiynau electronig

Dangosydd eitem ddigidol (DOI)

  • Thomas Caspari
  • Naomi Coulton
    Bangor University
Why the DNA damage checkpoint kinase Chk1 protects the genome of lower and higher eukaryotic cells differentially is still unclear. Mammalian Chk1 regulates replication origins, safeguards DNA replication forks and promotes fork progression. Conversely, yeast Chk1acts only in G1 and G2. We report here that the mutation of serine 173 (S173A) in the activation loop of fission yeast Chk1 abolishes the G1-M and S-M checkpoints without affecting the G2-M arrest. Although Chk1-S173A is fully phosphorylated at serine 345 by the DNA damage sensor Rad3 (ATR) when DNA replication forks break, cells fail to stop the cell cycle. Mutant cells are uniquely sensitive to the DNA alkylation agent methyl-
methanesulfate (MMS). This MMS sensitivity is genetically linked with the lagging strand DNA polymerase delta. Chk1-S173A is also unable to block mitosis when the G1transcription factor Cdc10 is impaired. Serine 173 is equivalent to lysine 166 in human Chk1, an amino acid important for substrate specificity. We conclude that the removal of serine 173 impairs the phosphorylation of a Chk1 target that is important to protect cells from DNA replication stress.
Iaith wreiddiolSaesneg
Rhif yr erthyglJOCES/2017/208652
Tudalennau (o-i)1840-1850
CyfnodolynBiology Open
Cyfrol6
Dynodwyr Gwrthrych Digidol (DOIs)
StatwsCyhoeddwyd - 2017
Gweld graff cysylltiadau