Figure 6.

No functional distinction between L- and S-OPA1 in maintaining respiratory complexes and mtDNA. A, respiratory complexes after starvation assessed by BNGE. Starvation does not significantly affect the complex levels except for complex I. Increased complex I levels were seen after starvation across the cell lines. * in the complex IV blot indicates a potential dimer. B, expression of OPA1 variants in OPA1-KO cells restores mtDNA levels. mtDNA and nuclear DNA were quantified using PCR with primer sets for ATP6 and GAPDH, respectively. OPA1-KO cells contain ∼30% of mtDNA copy number compared with WT cells. All three OPA1 variant cells showed ∼60% of the WT level, indicating partial recovery of mtDNA copy numbers. n = 4. Error bars are S.E. (Student's t test (two-tailed)).