Figure EV1. Dose‐dependent action of PIKK inhibitors.

Western blots of WT (NL‐550) cells treated for 1 h with neocarzinostatin (NCS; 20 ng/ml) or hydroxyurea (HU; 1 mM) in the presence of the indicated inhibitors. The inhibitors were added to the cultures 30 min prior to the addition of NCS or HU.

• A
  ATMi inhibited ATM in a dose‐dependent manner, as demonstrated by the phosphorylation of S824/KAP‐1.
• B
  DNA‐PKi inhibited DNA‐PK in a dose‐dependent manner, as demonstrated by the autophosphorylation of S2056/DNA‐PKcs.
• C, D
  ATRi inhibited ATR in a dose‐dependent manner, as demonstrated by HU‐induced phosphorylation of S345/CHK1.