FIGURE 5.

Region encoded by amino acids Ala⁷¹³–Asp⁷³⁰ is sufficient for endocytosis but not for TGN localization. Upper panels, Chimeric proteins were constructed composed of the luminal and transmembrane domains of Tac (CD25) and (parts of) the cytoplasmic domain of PC7, and antibody uptake experiments were performed (30 min 4 °C, 15 min 37 °C). When the cytoplasmic tail of Tac was swapped with the cytoplasmic tail of PC7 or only with part of the cytoplasmic tail of PC7 (between Ala⁷¹³ and Asp⁷³⁰), PC7 was still endocytosed. Lower panels, transfected cells were fixed, and Tac was subsequently visualized by immunofluorescent staining. Both Tac-PC7cyt and TaPC7cyt-D⁷³⁰ were found to be concentrated in the TGN, but Tac-PC7cyt-A⁷¹³-D⁷³⁰ was not. Scale bar = 10 μm.