Fig. 1.

dSirt4 is localized to mitochondria. (A) Subcellular fractionation of dSirt4::Flag cells shows mitochondrial localization. Homogenates from S2 cells expressing dSirt4::Flag were fractionated into mitochondria-enriched heavy membrane (HM), light membrane (LM), and cytosolic (Cyt) fractions, and analyzed by Western blot. The mitochondrial protein MnSOD and cytosolic proteins tubulin and Hsp90α are shown as fractionation controls. (B) Immunofluorescence of dSirt4 constructs confirms mitochondrial localization. dSirt4::Flag (Top) or dSirt4::GFP (Bottom) colocalizes with MitoTracker dye (Top) or MnSOD (Bottom) in mitochondria of S2 cells. (Scale bar, 10 μm.)