Damage-induced DNA replication stalling relies on MAPK-activated protein kinase 2 activity

• Published in: Proceedings of the National Academy of Sciences - PNAS 2013-10, Vol.110 (42), p.16856-16861
• Main Authors: Köpper, Frederik, Bierwirth, Cathrin, Schön, Margarete, Kunze, Meike, Elvers, Ingegerd, Kranz, Dominique, Saini, Priyanka, Menon, Manoj B., Walter, David, Sørensen, Claus Storgaard, Gaestel, Matthias, Helleday, Thomas, Schön, Michael P., Dobbelstein, Matthias
• Format: Article
• Language: English
• Subjects: Animals; Antimetabolites, Antineoplastic - pharmacology; Apoptosis; Biological Sciences; Cell cycle; Cell Line, Tumor; Cell- och molekylärbiologi; Cells; Checkpoint Kinase 1; Deoxycytidine - analogs & derivatives; Deoxycytidine - pharmacology; DNA; DNA Damage; DNA polymerase; DNA Replication; DNA, Single-Stranded - genetics; DNA, Single-Stranded - metabolism; G2 Phase Cell Cycle Checkpoints; Gene Knockdown Techniques; Histones - genetics; Histones - metabolism; Humans; Interphase; Intracellular Signaling Peptides and Proteins - genetics; Intracellular Signaling Peptides and Proteins - metabolism; Irradiation; Kinases; MAP Kinase Signaling System; Medicin och hälsovetenskap; Medicinska och farmaceutiska grundvetenskaper; Mice; Mice, Knockout; Nucleosides; p38 Mitogen-Activated Protein Kinases - genetics; p38 Mitogen-Activated Protein Kinases - metabolism; Phosphorylation; Protein Kinases - genetics; Protein Kinases - metabolism; Protein-Serine-Threonine Kinases - genetics; Protein-Serine-Threonine Kinases - metabolism; Small interfering RNA; Ultraviolet radiation; Ultraviolet Rays
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1304355110

DNA damage can obstruct replication forks, resulting in replicative stress. By siRNA screening, we identified kinases involved in the accumulation of phosphohistone 2AX (γH2AX) upon UV irradiation-induced replication stress. Surprisingly, the strongest reduction of phosphohistone 2AX followed knockdown of the MAP kinase-activated protein kinase 2 (MK2), a kinase currently implicated in p38 stress signaling and G2 arrest. Depletion or inhibition of MK2 also protected cells from DNA damage-induced cell death, and mice deficient for MK2 displayed decreased apoptosis in the skin upon UV irradiation. Moreover, MK2 activity was required for damage response, accumulation of ssDNA, and decreased survival when cells were treated with the nucleoside analogue gemcitabine or when the checkpoint kinase Chk1 was antagonized. By using DNA fiber assays, we found that MK2 inhibition or knockdown rescued DNA replication impaired by gemcitabine or by Chk1 inhibition. This rescue strictly depended on translesion DNA polymerases. In conclusion, instead of being an unavoidable consequence of DNA damage, alterations of replication speed and origin firing depend on MK2-mediated signaling.