Hsp70 co-immunoprecipitates with p53-S269D. A, H1299 cells were transiently transfected with p53 wild type, S269A, or S269D, and total p53 was immunoprecipitated (IP) using DO-1. Co-immunoprecipitating Hsp70 was detected by immunoblotting (IB). Bottom panel, equal immunoprecipitation of p53 from lysates was determined by blotting with anti-rabbit p53 (CM-1). Total Hsp70 (B) and Hsp90 (C) levels in H1299 cells following transfection with p53 wild type, S269A, or S269D were determined by immunoblotting.