Fig. 4

FOXO3 truncation mutant proteins retain the DNA binding domain. a Disruption of the FOXO3 gene as described in “Methods” led to a truncated protein that was 349 amino acids in length. This mutant protein retained the FOXO3 DNA binding domain, but lacked the transactivation domain. b Total protein lysates prepared from FOXO3 mutant-containing cells and control cells were examined by western blot analysis; employed antibodies are indicated. Wild-type FOXO3 was approximately 80 kDa, whereas, mutant FOXO3 protein was approximately 45 kDa. Out of 77 putative mutants screened, only four were homozygous mutant (confirmed by Sanger sequencing)