Fig. 3. Exogenously expressed EGFP-Rab27a localizes with WPB in HUVECs. HUVECs were transfected with expression vectors for either EGFP-Rab27a (A-C) or MYC-Rab1a (D-F) and, 24 hours later, fixed, permeabilized and immunolabelled for VWF (A-C) or VWF and the MYC epitope (D-F). VWF immunoreactivity is shown in (A,D) and is red in (C,F). EGFP fluorescence and MYC immunoreactivity are shown in (B) and (E), respectively, and are green in (C) and (F), respectively. A single EGFP-Rab27a-expressing cell can be seen in (B) and, in green, in (C). The arrows in (C) point to WPBs that are positive for both VWF and EGFP-Rab27a, and the curly bracket in (A) delineates a group of juxtanuclear WPBs that are EGFP-Rab27a negative. Scale bars, 20 µm (C,F).