Figure 7. Sp1 and p53 interaction under TPA treatment depends on the phosphorylation status of p53 residue 378.

(A) When C9 cells were subjected to TPA treatment, Sp1 could immunoprecipitate p53 significantly more than the DMSO mock-treated sample. p53 could reciprocally immunoprecipitate Sp1 relative significantly in TPA-treated cells more than the DMSO mock-treated sample. The input samples consisted of 10% of the lysate subjected to IP (B) When H1299 cells were transfected of different p53 mutants, the p53 378D mutant was able to immunoprecipitate Sp1 to a greater extent than the p53 378A mutant. Sp1 could reciprocally immunoprecipitate the p53 378D mutant significantly more than the p53 378A mutant.