Figure 7.

FTDP-17 missense mutations decrease the binding of tau to MT. Cell lysates from CHO cells stably expressing Wt or mutant tau were separated into cytoskeletal (P) and soluble fractions (S) after MT assembly. The amount of tau and α-tubulin present in each fraction was determine by immunoblot analysis with I¹²⁵-conjugated secondary antibody for quantification (A and C). (B and D) Quantitation of the percentage of tau in the soluble fraction relative to the total amount of tau present. Note that the ΔK and VPR mutations significantly reduce the binding of tau to MT, leaving more of these mutant proteins free in the soluble fraction. (n = 4, *p < 0.01), and that the dramatic loss of MT binding was evident in three different CHO cell clones that expressed the VPR tau mutants (C and D).