There is presently no efficient method to produce mutants of mitochondrial genes.
In the present study, for the first time we obtained data, demonstrating that different segments of the aortic intima, both normal and having atherosclerotic lesions of varying severity, may differ in heteroplasmy level of mutant allele of mitochondrial genome.
To detect a heteroplasmy level in the samples investigated, a new original method of quantitative assessment of the mutant allele of mitochondrial genome [ 22, 23], based on pyrosequencing technology, was developed by the authors [ 24].
The above considerations raise an important methodological problem, since quantitative evaluation of a mutant allele of mitochondrial genome may be a keystone for diagnostics of individual genetic predisposition to the disease, including atherosclerosis and oncopathology.
Therefore, quantitative evaluation of a mutant allele of mitochondrial genome is an obvious methodological challenge, since it may be a keystone for diagnostics of individual genetic predisposition to the disease.
Chromosomal breakage of mtDNA near OH and OL, manifested by the presence of a linear ∼11-kb double-stranded mtDNA fragment corresponding to the major arc, has been associated with replication pausing in a mouse model expressing a proofreading-deficient mutant of the mitochondrial DNA polymerase gamma [Polγ, 'mutator mouse', (28, 29)].
In Saccharomyces cerevisiae, vanillin is likely to be converted to vanillyl alcohol and vanillic acid by oxidoreductase enzyme(s) [ 14], and a mutant of the mitochondrial superoxide dismutase (Mn-SOD) gene (SOD2) was shown to exhibit enhanced vanillin-induced growth inhibition [ 15].
Moreover, the activity was demonstrated to be sensitive to nuclease and protease treatment, indicating that it is a ribonucleoprotein that requires nucleus-encoded protein(s) for function, the latter inferred from the fact that yeast mitochondrial DNA (mtDNA) deletion mutants devoid of mitochondrial protein synthesis, but retaining the RNase P RNA locus, still have RNase P activity [60].
However, our present finding on the different Ca2+ sensitivities of the UCP3 mutants and the comparison with the wild-type UCP3, provide important information that can explain the observed differences in the contribution of UCP3 mutants to mitochondrial uptake of Ca2+ supplied varyingly strong from different sources.
Accordingly, the mutation in the 171/172 amino acids results in a mutant with remaining high Ca2+ sensitivity for achieving uptake of entering Ca2+, while the contribution of this UCP3 mutant to mitochondrial uptake under high Ca2+ conditions (i.e. intracellular Ca2+ release) is prevented.
