Enzyme Controlling Ageing Process in Yeast Identified



Scientists working at John Hopkins Institute, along with researchers from National Taiwan University, have identified a protein in the yeast cells which is responsible for controlling its life span. This particular protein is found in young yeast cells but decreases as the age of the yeast cell advances. Removing the protein from the cell shortens its life span, whereas replacing it extends the life of the cell. Thus, the life span of the yeast cell can be manipulated.
The breakthrough has been reported in the journal “Cell."  Earlier, it had been reported that the longevity of a yeast cell depends upon calorie restriction. But the new mechanism is completely different fro the one described earlier. In the latest research, scientists have identified a protein called as Sip2 in the yeast cell. They observed that acetylation of this specific protein affected its life span. A normal yeast cell replicates 25 times in its normal life span. However, when an acetyl group is added to Sip2, it can replicate more than 38 times, which is 50% more of its normal course.
As yeast cells age, they take longer to replicate because of de-acetylation.  The researchers conducted experiment on live yeast cells, using chemicals which resembled acetylated and de-acetylated forms of Sip2. They observed that the normal yeast cells had a lifespan of 25 generations. However, the genetically modified yeast cells with acetylated Sip2 had an extended life span of 38 generations.
According to Dr. Jin- Ying Lu, the first author of the study, from the National Taiwan University, acetylation of the Sip2 protein was an anti- ageing therapy which extended the life span of the yeast cell. This is the first time that a biochemical route of ageing has been discovered. The scientists are interested in knowing whether a similar pathway exists in mammalian cells as well. If that is found to be true, it will be possible to maintain youthfulness in mammals.
Saturday, October 1, 2011