Figure 2.

Tau phosphorylation levels increase at Ser262, but not at Ser202 or Thr231, when Chk2 is co-expressed in fly eyes. Fly heads expressing human tau alone (tau) or with Drosophila Chk2 (tau + Chk2) driven by the pan-retinal gmr-GAL4 driver were subjected to western blotting with anti-tau (human tau) or anti-phospho-tau antibodies. The phosphorylation levels at each site in fly heads co-expressing tau and Chk2 are normalized to the tubulin level and shown as a ratio relative to that in fly heads expressing tau alone. Asterisks indicate significant differences from control (n = 4 or 5, P < 0.05, Student's t-test). Representative blots are shown.