SENS 2 Report: Moving Mitochondria
Frank Rummel has another of his SENS 2 reports up for your reading pleasure. This time, the focus is on progress towards copying mitochondrial genes into the cellular nucleus - this is one of biomedical gerontologist Aubrey de Grey's proposed strategies for mitigating age-related cellular damage. Mitochondrial DNA is essential to the functioning of our cells, but is damaged much more readily than nuclear DNA; this damage is implicated as a cause of a range of age-related degenerative conditions.
Dr. de Grey says,"Rather than fixing mitochondrial mutations, we can obviate them. We can make copies of those 13 genes and put these copies into the chromosomes in the nucleus. Then, if and when the mitochondrial DNA gets mutated so that one or more of the 13 proteins are no longer being synthesised inside the mitochondria, it won't matter -- the mitochondria will be getting the same proteins from the nucleus."This is exactly what Dr. Weiner has done; the frst case of one of these 13 mitochondrial proteins in particular having the gene for making it expressed in the nucleus rather than in the mitochondrial DNA. More details can be found in Professor Weiner's abstract of his SENS 2 presentation entitled "Factors that might affect the allotopic replacement of a damaged mitochondrial DNA-encoded protein".
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Professor Weiner cautioned me that they had worked with the easiest case of the 13 mitochondrial component proteins, and that the remaining 12 would be much more difficult to solve because they are so difficult to get at. In very simple terms, working with the 13 is complicated by the fact that simply pulling aside what surrounded what you are trying to get at jeopardized the very thing you were trying to get at due to the complexity of all the interactions involved.
But still, that's a promising step forward. Another strategy for dealing with damaged mitochondrial DNA is to replace it with fresh, new, undamaged DNA - a more conventional task of repair for those of us familiar with everyday machinery. At least one group has achieved early success in developing the tools needed to perform this repair, using a technique called protofection.