Fig. 3.

Light-induced PIP₃ production promotes GLUT4 translocation in 3T3-L1 adipocytes. 3T3-L1 adipocytes were electroporated with CIBN–CaaX, CRY2–iSH2 and IRAP–pHluorin plasmids. The cells were activated with 500-ms pulses of blue light (488 nm, 10 mW) at 5-s intervals under TIRF illumination, and GLUT4 translocation was evaluated using IRAP–pHluorin signals on the cell surface. (A) TIRF images of a 3T3-L1 adipocyte before and after 10 min of activation with 488-nm light. (B) Kymograph image shows the dynamics of IRAP translocation to the cell surface (ROI from the box in Fig. 3A). (C) Quantification of IRAP translocation under the conditions indicated. ΔF/F₀, image intensities were normalized to the intensity measured before insulin and blue light stimulation. (n=5 cells, data are mean±s.e.m.). Scale bar: 10 μm (A).