Dual-mode of insulin action controls GLUT4 vesicle exocytosis

The stably TUG KD 3T3-L1 adipocyte was electroporated with VAMP2-pHlorin and imaged by TIRFM at 5 Hz under the control of Andor iQ software. The raw 8 bits tiff images were used to make the video 4 and only brightness and contrast were adjusted. Of note: 1) pHlourin’s fluorescence brightens on opening of the fusion pore, and diffuses laterally as the vesicle fully collapses into the plasma membrane; 2) Insulin promoted a transient increase in the fusion rate.