Stable nuclear expression ofATP8andATP6genes rescues a mtDNA Complex Vnullmutant

Abstract

We explore the possibility of re-engineering mitochondrial genes and expressing them from the nucleus as an approach to rescue defects arising from mitochondrial DNA mutations. We have used a patient cybrid cell line with a single point mutation in the overlap region of the ATP8 and ATP6 genes of the human mitochondrial genome. These cells are null for the ATP8 protein, have significantly lowered ATP6 protein levels and no Complex V function. Nuclear expression of only the ATP8 gene with the ATP5G1 mitochondrial targeting sequence appended restored viability on Krebs cycle substrates and ATP synthesis capabilities but, failed to restore ATP hydrolysis and was insensitive to various inhibitors of oxidative phosphorylation. Co-expressing both ATP8 and ATP6 genes under similar conditions resulted in stable protein expression leading to successful integration into Complex V of the oxidative phosphorylation machinery. Tests for ATP hydrolysis / synthesis, oxygen consumption, glycolytic metabolism and viability all indicate a significant functional rescue of the mutant phenotype (including re-assembly of Complex V) following stable co-expression of ATP8 and ATP6. Thus, we report the stable allotopic expression, import and function of two mitochondria encoded genes, ATP8 and ATP6, resulting in simultaneous rescue of the loss of both mitochondrial proteins.

Transformation of nad7 into the nuclear genome rescues the slow growth3 mutant in Arabidopsis

“…In addition to plants, allotopic expression of mitochondrial genes in the nucleus was proposed as a potential method for gene therapy [30]. Recently, stable nuclear expression of ATP8 and ATP6 genes was shown to rescue a Complex V null mutant derived from a patient cybrid cell line carrying a mutation in the human mitochondrial genome [31]. Thus far, nad7 is the only mitochondrial gene reported to be successfully expressed in the nucleus in plants.…”

Cellular Mechanisms of Circulating Tumor Cells During Breast Cancer Metastasis

“…Studies have shown an association between breast cancer and mutations on ATP6 and ATP8 genes that encode the a-subunit of the F 1 Fo ATP synthase [ 114 , 115 , 116 ]. The a-subunit is critical in the rotation of F 1 Fo ATP synthase, a necessary process during ATP production; therefore, ATP6 and ATP8 mutations negatively influence mitochondrial energy metabolism [ 117 ]. In addition to mutation, breast cancer pathology alters the abundance of other subunits of the F 1 Fo ATP synthase [ 118 ].…”

Peer Review #2 of "Comparative proteomics analysis reveals the difference during antler regeneration stage between red deer and sika deer (v0.1)"

“…Of these 6 up-regulated proteins, vacuolar-type H-ATPase subunit E (ATP6E) belong to superfamily of related ATP synthases. Co-expression of ATP8 and ATP6 genes provided stable protein expression for complex V assemble of the oxidative phosphorylation complexes (Boominathan et al 2016). The upregulation of V-ATPase gene (ATP6V0D2) was found in the zone of hypertrophic chondrocytes, which was part of the process of endochondral ossification (Ayodele et al 2017).…”