Western blot analysis of GSK3β levels and tau phosphorylation. HEK293 cells were transiently transfected with equal amounts of plasmid. A. Expression of exogenous AICD increases total GSK3β protein. Expression of CT-GFP in addition to AICD reduces GSK3β to control levels. Expression of tau has no effect on levels of GSK3β. NT = Not Transfected control. B. The presence of exogenous CT-GFP increases phosphorylation of G272V and P301L at Ser199/Ser202 and Thr231. Expression of CT-GFP has no effect on 441WT, R406W, or R5H tau phosphorylation at any epitope probed.