Figure 1. MTS AAV-capsid localizes within mitochondria where the delivered wild-type human ND4 is translated in cultured cells. A: Illustration of the COX8 MTS fused in frame with GFP and inserted into the VP2 capsid of AAV. B: Illustration of the mitochondrial heavy strand promoter (HSP) driving expression of the mitochondrial mutant human ND4 subunit of complex I to which is appended a FLAG epitope. C: Fluorescence microscopy of live cultured cells infected with the COX8GFP VP2 MTS AAV revealed punctate and perinuclear expression of GFP suggestive of mitochondrial localization. D: MitoTracker Green staining of mitochondria surrounds nuclei labeled with DAPI. E: Transmission electron microscopy shows silver enhanced GFP immunogold inside mitochondria as well as within the nucleus. F: ND4FLAG immunogold is evident only within the mitochondria. Abbreviations m=mitochondria and n=nucleus.