Endocytosis of GLP-1/<i>h</i>IgG2 is via a dynamin dependent manner.

<p>(A) Internalization of GLP-1/hIgG2-Fc in INS-1 cells (A) Cells were incubated with 1 µM GLP-1/<i>h</i>IgG2 at 4°C for 30 minutes, then switched to 37°C for 0, 10, 20 and 60 minutes. After fixation and blocking for non-specific binding, cells were then incubated with goat-anti-human IgG antibody (1∶500) followed by secondary Cy3-conjugated anti-goat antibody (1∶500) and Top3 dye (1∶20,000) for nuclei staining. The images were then visualized by a confocal microscope. (B) The internalization experiments were performed in cells co-transfected with either wild type dynamin or dominant negative dynamin and green fluorescent protein (GFP). 24 hours after transfection, internalization of GLP-1/<i>h</i>IgG2-Fc was conducted as described in (A). DAPI (1∶10,000) was used for nuclei staining and images were taken by a Nikon fluorescent microscope.