Figure 2.

Phosphorylation of htt increases localization of kinesin-1 to microtubules. (A) Huntingtin-mediated control of BDNF trafficking is MT dependent. Time projection and velocity show that nocodazole treatment of cortical neurons significantly reduces motility of BDNF vesicles, whereas latrunculin B has no marked effect. (B) S421-phosphorylated htt is present on MTs in COS7 cells. Cells are immunostained using anti-phospho-htt-S421–714 and anti-α-tubulin antibodies. (C) Compared with unphosphorylatable htt (htt-S421A), expression of S421 constitutively phosphorylated htt (htt-S421D) in neuronal cells significantly increases the percentage of KHC-positive dots decorating microtubules. The localization of DIC is unchanged in both conditions (^**P<0.01; see Supplementary data for detailed statistical analyses and number of measures).