The ATM-Chk2 DNA damage response pathway is rapidly deactivated in YAP over-expressing cells
(A) Representative western blot analysis of GFP- or YAP-transduced CGNPs at the indicated time points after irradiation. CGNPs over-expressing YAP at one and three hours post-irradiation showed reduced levels of inhibited (Tyr-15 phosphorylated) Cdk1, and higher levels of cyclin B1 indicating increased entry into mitosis.
(B) Western blot analysis of GFP- or YAP-transduced CGNPs (left) or NeuroD2-SmoA1 cells (MBCs) (right) at the indicated times after irradiation. YAP-transduced CGNPs show lower levels of phosphorylated ATM and Chk2 3 hours after radiation, compared to GFP-transduced cells. Similar results were observed in irradiated MBCs transduced with either GFP or YAP. Quantification of phosphorylated ATM and Chk2 levels are shown at the bottom. YAP expression did not differentially affect chk1 or p53 levels or phosphorylation.