ENU treatment induced a T-to-A mutation, resulting in a valine to aspartic acid substitution at amino acid 26 (p.V26D) in an invariant N-terminal sequence motif. Western blot analysis indicated protein expression was increased 1.6 and 2.2 fold in heterozygous and homozygous embryos, respectively, relative to wild-type mice. Protein half-life is increased in homozygous MEFs relative to wild-type MEFs.