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Physiology & Medicine / Re: What is the structure of telomerase?
« on: 25/09/2012 19:50:11 »
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
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.
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.