Figure 3.

TG2 colocalizes with LC3 in the autophagosomes. (a and b) Immunofluorescence microscopy analysis of 2fTGH-GFP-LC3 cells undergoing autophagy. Cells expressing GFP-LC3 protein were cultured in complete medium (a) or subjected to starvation (b) in EBSS for 16 h, stained with an anti-TG2 antibody and analyzed by microscopy. Green dots represent autophagosomes, red dots TG2 protein, and yellow dots sites of overlap of GFP-LC3 with TG2. Scale bar, 6 μm. (c and d) Immuno-gold analysis in human 2fTGH cells double-labeled against TG2 (15-nm gold particles) and p62 (5-nm gold particles). The colloidal gold particles, indicating the presence of TG2 (arrows) and p62 (arrowheads), were detected in typical autophagosome-like structures. Original magnification: × 85 000