Table 2.

Additive versus synergistic cell death induced by co-expression of tau and GSK3β (S9A)

Tau	% Cell death (Additive) = GFP/GSK3β(S9A) + GFP/tau	% Cell death (Actual) = GFP/GSK3β(S9A)/ tau	p value
352tauWT	24.1% ± 1.44	57.3% ± 1.74	p < 0.005
441tauWT	24.7% ± 0.95	29.1% ± 2.77	N.S.
352tauPHP	25.5% ± 1.52	49.8% ± 3.63	p < 0.005
R5H	25.1% ± 1.62	43.4% ± 1.37	p < 0.005
K18	25.9% ± 1.40	46.3% ± 2.44	p < 0.005
K18ΔK280	46.4% ± 1.00	76.4% ± 4.84	p < 0.005
P301L	25.2% ± 1.37	55.3% ± 1.45	p < 0.005
G272V	25.8% ± 2.88	27.8% ± 3.13	N.S.
R406W	24.3% ± 1.14	43.0% ± 3.33	p < 0.005

Values of cell death obtained when GFP/GSK3β (S9A) or GFP/tau transiently expressed were added together and compared to the actual values of cell death obtained when GFP/GSK3β (S9A)/tau were co-expressed. Synergistic cell death (bold entries) was observed when GSK3β (S9A) was co-expressed with 352PHP, R5H, K18, K18ΔK280, P301L, or R406W. Interestingly, cell death in the presence of G272V was not affected by the presence of GSK3β (S9A). N.S. = not significant.