pARIS-mCherry-httQ23 facilitates BDNF transport through interaction with dynein and HAP1. A) Fast 3D videomicroscopy was performed to analyze the dynamics of BDNF-eGFP-containing vesicles in mouse neuronal cells expressing BDNF-eGFP alone or cotransfected with pARIS-mCherry-httQ23/Q100 or dynein/HAP1 deletion mutants. Overexpression of pARIS-mCherry-httQ23 recapitulates the transport function of wild-type htt and significantly increases the mean velocity of BDNF-containing vesicles compared to controls values (BDNF transfection alone). Nor the polyQ version neither pARIS-htt deletion mutants are able to stimulate the transport of BDNF containing vesicles. The pausing time of moving vesicles is quantified in (B). Mean overall velocity is indicated as μm/sec. Data were obtained from three independent experiments (control: 4805 tracks from 39 cells; pARIS-mCherry-httQ23: 1970 tracks from 20 cells; pARIS-mCherry-httQ100: 1670 tracks from 18 cells; pARIS-mCherry-httQ23-Δdyn: 4603 tracks from 25 cells; pARIS-mCherry-httQ23-ΔHAP1: 4029 tracks from 20 cells). Fisher's analysis: *P < 0.05; **P < 0.01, NS, non significant.