Fig. 5. Synapsin I remains associated with the Golgi in cells exposed to cytoskeletal-disrupting agents. (A) Nocodazole treatment causes synapsin I to disperse in punctate structures throughout the cytoplasm, in a similar manner to TGN38. NRK cells were treated with 33 µM nocodazole for 1 hour at 37°C, then fixed and stained for tubulin or double stained for synapsin I and TGN38. Tubulin staining shows complete microtubule depolymerization in nocodazole-treated cells. (B) Cytochalasin D treatment has no effect on synapsin I distribution in NRK cells. NRK cells were treated for 2 hours with 5 µM cytochalasin D. FITC-phalloidin staining reveals F-actin disruption in cytochalasin D-treated cells. Staining for synapsin I reveals punctate staining at cell center, similar to untreated cells. Asterisks mark cell nuclei. Bar, 10 µm.