Figure 6.

Different distributions for two forms of Dyn 1-GFP in Clone 9 cells. Stably transfected Clone 9 cells expressing Dyn 1(ab)-GFP were immunostained with antibodies to clathrin (a–a") or labeled with internalized fluorescent dextran (b–b") to identify the endosomal and lysosomal compartments. Whereas the Dyn 1(ab)-GFP appeared to colocalize precisely with clathrin-coated pits at the plasma membrane (boxed regions), there was no colocalization with clathrin at the Golgi apparatus. Large vesiclular structures associated with Dyn 1-GFP patches were seen in these transfected cells and had no colocalization with endocytosed dextran (b–b") suggesting that these structures do not represent a lysosomal compartment. In contrast to Dyn 1(ab)-GFP, Dyn 1(bb)-GFP exhibited a diffuse cytoplasmic distribution in transfected cells with some localization to the Golgi apparatus (arrows), as confirmed by double-immunofluorescence staining for clathrin (c–c") and the trans-Golgi protein TGN38 (d–d"). Bar, 10 μm.