FIGURE 1.

Myo5a-dependent neuronal vesicle motility requires a Rab GTPase. A, vesicle motility in squid axoplasm was inhibited by 99% at 20 μm GST-RabGDI compared with controls (0 μm). All data are mean ± S.D. of three independent experiments. B, 20 μm GST-RabGDI did not affect actin filament network formation as visualized by fluorescence microscopy after incubation with 0.5 μm rhodamine-phalloidin. Bar, 5 μm. C, GST-RabGDI was used in an affinity column to isolate Rab GTPases from squid brain. Western blots of eluted fractions probed with antibodies to GST (lane 1) and Rab3A (lane 2) revealed the presence of Rab3A. Rab3A was not present if no RabGDI was applied to affinity column (lane 3).