Figure 5. INPP4B loss results in concomitant loss of BRCA1, ATR and ATM protein levels.

A. INPP4B^fl/fl MEFs were infected with increasing amounts of Ad5Cre and blots probed for INPP4B, ATM, ATR, BRCA1 and p42/44 total protein levels. B. Quantitation of percent average protein expression to control treated INPP4B^fl/fl MEFs. C. MG132 proteasome inhibitor treatment of Ovca433 shRNA-Renilla luciferase and shRNA-INPP4B cell pools. Western blots were probed for INPP4B, ATM, ATR and BRCA1. D. Flag-INPP4B interacts with ATR and BRCA1 but not with ATM and PTEN in 293T immunoprecipitation experiments. E. GST-pull down experiments using bacterially expressed INPP4B N-terminal (aa1–460), middle (aa200-aa760) and C-terminal (aa460-aa924) fragments and ATR or BRCA1 overexpressed in unchallenged 293T cells.