FIGURE 7:

Myosin Va depletion affects Rab motility and organelle distribution. (A) A HeLa cell line stably expressing GFP-Rab6A′ was transfected with control or myosin Va siRNA for 72 h. Two-minute time-lapse movies were recorded on a spinning disk confocal microscope. Representative frames from Supplemental Movie S1. Black arrows indicate tubules emerging from the Golgi complex. (B) Quantification of the number of Rab6A′-positive tubules connected to the Golgi for each condition (mean ± SEM; n = 11–15 cells). Two independent siRNAs targeting myosin Va were used. **p < 10⁻³. (C) HeLa cells were transfected with control or myosin Va siRNA for 72 h and plasmid DNA encoding GFP-Rab11A for the final 18 h. Two-minute time-lapse movies were recorded on a spinning disk confocal microscope. Representative frames from Supplemental Movie S2. Insets depict zoomed images of the boxed region. Indicated are examples of immobile vesicles (orange arrowheads) and rapidly moving vesicles (blue arrowheads). Closed arrowheads indicate the position of the vesicle in the first frame (recorded at 32 s), and the open arrowheads indicate the position of the same vesicle in the given frame. (D) HeLa cells transfected with control or myosin Va siRNA for 72 h and plasmid DNA encoding GFP-Rab14 for the final 18 h. Two-minute time-lapse movies were recorded on a spinning disk confocal microscope. Representative frames from Supplemental Movie S3.