Fig. 1

The enzymes of the TCA cycle are also found in the nucleus. a Nuclei were isolated from mouse livers using a nuclei-specific, high-sucrose gradient centrifugation protocol. The purity of the nuclei was verified by western blotting analysis of cytoplasmic and mitochondrial proteins. Mitochondria were stained with MitoTracker Red (red), and nuclei were stained with Lamin B1 (green) or DAPI (blue). Bar, 10 μm. b Western blotting analysis of the extracts from nuclei isolated from mouse livers, HepG2 cells, or MCF-7 cells using antibodies against the indicated proteins. c Subcellular localization of the TCA cycle-associated enzymes in HepG2 cells was analyzed by immunofluorescent staining (green). DAPI was used to stain the nucleus (blue), and MitoTracker Red staining was included to visualize the mitochondria (red). Bar, 20 μm. d HepG2 cells were immunostained with antibodies against the TCA cycle-associated enzymes (green) or MitoTracker Red (red) and scanned at a 0.5-μm increment along the Z-axis using confocal microscopy. DAPI staining was used to visualize the nucleus (blue). Bar, 10 μm