Figure 3.

OGA-mBirA fusion proteins localize to and biotinylate proteins in the nucleus, cytoplasm, and mitochondria of U2OS cells. U2OS cells were transfected with pcDNA3.1 (A), OGA-mBirA-HA (B–D), or Myc-mBirA-OGA (E–G), treated with (A, C, D, F, and G) or without (B and E) biotin (25 μm, 16 h), and treated with (D and G) or without (A–C, E, and F) H₂O₂ (2.5 mm, 2 h). Cells were fixed, permeabilized, and stained for BirA and biotin. Nuclei and mitochondria were stained with Hoechst 33342 and MitoTracker Orange CMTMRos, respectively. White triangles indicate co-localization (orange) of MitoTracker and OGA (B and E). Images were acquired at ×63 magnification on a Zeiss Axio Examiner 710NLO-Meta multiphoton microscope. n = 3. Scale bar, 15 μm.