Figure 4.

rGIIA can reach mitochondria in PC12 cells from the extracellular space independently of its enzymatic inactivity. PC12 cells were incubated with 100 nM ⁵⁴⁶Alexa-rGIIA(D49S) for 3 h and mitochondria were labeled with MitoTracker Green FM dye. Cells were then analyzed with confocal microscopy. Representative confocal fluorescence microscopy image shows ⁵⁴⁶Alexa-rGIIA(D49S) (red) and MitoTracker-labeled mitochondria (green); colocalization in merged image is shown in white. The extent of colocalization of ⁵⁴⁶Alexa-rGIIA(D49S) and mitochondria in PC12 cells, expressed in terms of the Manders’ coefficient, was 0.05 ± 0.01, mean ± S.E.M., as calculated from 7 images. Scale bar, 10 µm.