Fig. 5.

SV40 LT STOP codon mutation and truncated LT expression in DT40 cells.

A. Sequencing chromatogram from clone 11 lined with reference SV40 LT sequence. Deletion of C base at position 1727 results in-frame TAG STOP codon immediately after deletion.

B. SV40 LT, GAPDH and AID protein expression in DT40 cell lines measured with western blot. SV40 LT and GAPDH expression was measured from DT40 wild-type, IgL⁽⁻⁾ and IgL⁽⁻⁾ AID knock-out cell lines. Clones (cl.) 6, 11 and 32 are IgL⁽⁻⁾ cells where SV40 LT expression cassette is integrated in to the deleted Ig light chain locus that lacks endogenous Ig enhancers (described previously in Refs. [31,33]). Protein size is indicated in left. Truncated LT is marked with arrow.