• Quasi-TIRFM;
  • live-cell imaging;
  • post-Golgi transport;
  • transforming growth factor β receptor II;
  • green fluorescent protein


Transforming growth factor β receptor II (Tβ RII) is synthesized in the cytoplasm and then transported to the plasma membrane of cells to fulfil its signalling duty. Here, we applied live-cell fluorescence imaging techniques, in particular quasi-total internal reflection fluorescence microscopy, to imaging fluorescent protein-tagged Tβ RII and monitoring its secretion process. We observed punctuate-like Tβ RII-containing post-Golgi vesicles formed in MCF7 cells. Single-particle tracking showed that these vesicles travelled along the microtubules at an average speed of 0.51 μm/s. When stimulated by TGF-β ligand, these receptor-containing vesicles intended to move towards the plasma membrane. We also identified several factors that could inhibit the formation of such post-Golgi vesicles. Although the inhibitory mechanisms still remain unknown, the observed characteristics of Tβ RII-containing vesicles provide new information on intracellular Tβ RII transportation. It also renders Tβ RII a good model system for studying post-Golgi vesicle-trafficking and protein transportation. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)