Naked Science Forum
Life Sciences => Physiology & Medicine => Topic started by: thedoc on 25/09/2012 17:30:01
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ARCC asked the Naked Scientists:
Could anyone explain the structure of the enzyme telomerase? How does it work?
What do you think?
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To be honest, I think this diagram that I found on Wiki pretty much sums up how telomerase works well.
http://en.wikipedia.org/wiki/File:Working_principle_of_telomerase.png (http://en.wikipedia.org/wiki/File:Working_principle_of_telomerase.png)
It's an enzyme with reverse transcriptase activity, and it carries an RNA that serves as a template to extend the shortened end of the DNA. The DNA is shortened each time the cell replicates, due to certain complications within DNA replication. To stop this from causing lots of damage to the cell and triggering all sorts of problems, the ends (telomeres) of the DNA are just lots of repeats, so it doesn't matter what happens to them.
Telomerase is of interest because it's often activated in cancer and results in the cells becoming immortal. Normal cells have a certain limit on the number of times their DNA can be replicated called the Hayflick limit, and this is thought to be strongly related to the ageing process. Cancer cells, by activating telomerase, can bypass this limit and are capable of replicating indefinitely. MCF-7 is a well-known cancer cell line, and the original cells were harvested in 1970.
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Potential telomere therapies will be walking a fine line:
Some experiments have raised questions on whether telomerase can be used as an anti-aging therapy, namely, the fact that mice with elevated levels of telomerase have higher cancer incidence and hence do not live longer.
http://en.wikipedia.org/wiki/Telomerase
Maybe preventing cancer is easier than curing it? This would be a worthwhile first step before telomere therapy...