Figure 2
From: Brain-derived neurotrophic factor receptor TrkB exists as a preformed dimer in living cells
BiFC assay of TrkB homodimers. (A) HEK 293 cells were transfected with TrkB-VC alone, TrkB-VN alone, TrkB-VN and TrkB-VC, or TrkB-VN and EGFR-VC. Twenty-four hours after the transfection, Venus fluorescence signals were observed by confocal microscopy. This figure represents > 20 similar images observed. (B) HEK 293 cells co-expressing TrkB-VN and TrkB-VC were treated with (+) or without (-) 100 ng/ml of BDNF. The cells were fixed, and immunostained with anti-pTrkB primary antibody and then with fluorescently labeled secondary antibody. Fluorescence signals of Venus (green) and pTrkB (red) were observed by confocal microscopy. Note that the green and red fluorescence images do not completely overlap since TrkB-VN and TrkB-VC can form non-fluorescent homodimers. This figure represents > 20 similar images derived from four independent experiments. Bars, 10 μm. (C, D) HEK 293 cells co-expressing TrkB-VN and TrkB-VC (C), or the fusion receptor pair lacking the intracellular domain, TrkBΔICD-VN and TrkBΔICD-VC (D) were treated with (+) or without (-) 10 μg/ml BFA. The cells were fixed, and immunostained with anti-calnexin antibody and then with fluorescently labeled secondary antibody. These figures represent 15 similar images derived from three independent experiments. Bars, 10 μm.