Fig. 1.

In vitro motility and binding assay of purified p75-GFP-carrying vesicles. Purified p75-GFP-containing vesicles moved in vitro on rhodamine-labelled microtubules in an ATP-dependent manner. a Isolated vesicles were heated or subjected to protease digestion and the efficiency of vesicle binding to microtubules was compared to that in the control experiment. Asterisks denote statistically significant differences in the number of vesicles bound to microtubules using paired Student’s t tests; *p<0.01; bars standard error. b Selected frames from a live cell time-lapse. Moving vesicles are indicated by arrows and arrowheads. The movement is bidirectional, with a switch of microtubular tracks. The time is indicated in minutes (′) and seconds (′′). Scale bar 1 μm. c The velocity of p75-GFP vesicles was measured in three independent experiments. The mean velocity (mean) was the mean velocity of both types of movement: unidirectional (processive) and bidirectional (diffusive) (n=53). The velocity of only unidirectional (processive) movement was also measured (n=16). Example kymographs of the processive and diffusive movements are shown on the right panel