Compartmentalization of Mammalian Pantothenate Kinases
Figure 11
Human PanK2 migrates from nucleus to mitochondria.
HeLa cells were transfected with the expression plasmid pAA275 encoding full-length hPanK2(1–570) fused to the green-to-red photoswitchable fluorescent protein Dendra2. The red-irreversibly-converted fluorescence was real-time tracked in living cells. The micrographs show two cells (before irradiation, panels a, b, c) expressing hPanK2-Dendra2, one cell showing “nuclear and mitochondrial” fluorescence and a second cell with “mitochondrial only” fluorescence. Dendra2 was selectively photoconverted within the indicated ROIs (white dashed ovals) for each cell (after irradiation, panels d, e, f) using brief illumination with 405 nm irradiation, and the fusion proteins were visualized in the green and red channels thereafter. After 4 hours (panels g, h, i), the photoconverted nuclear fraction of hPanK2 was associated with mitochondria (arrows, panels g, i) whereas the photoconverted mitochondrial hPanK2 in the other cell remained associated with mitochondria during the same time. Co-localization of both magenta and green hPanK2 fusion proteins associated with mitochondria are indicated by white pixels and arrows in the merged image (panel i). Scale bar, 10 µm.