Abstract
To introduce DNA into mitochondria efficiently, we fused adenoassociated virus capsid VP2 with a mitochondrial targeting sequence to carry the mitochondrial gene encoding the human NADH ubiquinone oxidoreductase subunit 4 (
ND4
). Expression of WT
ND4
in cells with the G11778A mutation in
ND4
led to restoration of defective ATP synthesis. Furthermore, with injection into the rodent eye, human
ND4
DNA levels in mitochondria reached 80% of its mouse homolog. The construct expressed in most inner retinal neurons, and it also suppressed visual loss and optic atrophy induced by a mutant
ND4
homolog. The adenoassociated virus cassette accommodates genes of up to ∼5 kb in length, thus providing a platform for introduction of almost any mitochondrial gene and perhaps even allowing insertion of DNA encompassing large deletions of mtDNA, some associated with aging, into the organelle of adults.
