Fig. 8. The Arm ED to QN mutant protein is stable, compared with the wild-type. (A) Transient expression experiment: 0.2 µg of pAcLacZ, together with 0.2 µg of pMK33 vector or various pMK-Arm-myc constructs were introduced into S2R+ cells, and after 36 h CuSO₄ was added for 12 h. Expression levels of myc-tagged Arm were analyzed by western blotting. Note relative β-galactosidase activities in the cell lysates were almost the same. (B) Stable expression experiments. Stably transfected cells (5 × 10⁶) were plated and expression of various myc-tagged Arm was induced with CuSO₄. Expression levels of myc-tagged Arm and Dα-catenin were analyzed (upper two panels). Total RNAs from these cells were subjected to northern blot analysis with Arm or RP49 probe (lower two panels).