Wt1^tm2Hst

The insertion of a Leu2/neo cassette resulted in the S395R amino acid substitution and a premature termination within ZF3 by inclusion of a translational stop codon at 396. This would cause a truncation of 7.3 kDa with the loss of 52 amino acids, including the KTS insert and ZF4, and would render ZF3 nonfunctional by removing its alpha-helix. Western blot analysis confirmed truncation of two of the four isoforms. Cell fractionation showed that the low level of mutant protein was not a result of retention in the cytoplasm, therefore, posttranscriptional events must account for the fact that only 5% of the protein is mutant. (J:53585)