Jack Szostak, Ph.D. ’77, Biochemistry
Aging may begin to show on our faces as crow’s feet and liver spots, but on the cellular level, it shows up in our telomeres. Acting something like the aglet at the end of a shoelace, these specialized sequences of DNA protect the chromosome ends from fraying and sticking to each other, which would destroy or scramble an organism’s genetic information.
When cells replicate, small bits of DNA are lost in order to enable the replication process. These bits are taken from the telomeres, rather than another part of the chromosome where they might serve an important function. So as the cells age and divide, the telomeres at the end of the chromosome become shorter and shorter. The telomere DNA is made by telomerase, a specific enzyme found in most cells of the body.
We’ve learned all this thanks to the work of Jack Szostak and his colleagues, Elizabeth Blackburn and Carol Greider. Their work has been so influential, in fact, that they were awarded the 2009 Nobel Prize for Physiology or Medicine for their discoveries of how telomeres function to protect chromosomes.
In addition to helping us better understand how and why cells age, their research may prove to have major implications for the treatment of cancer. Cancer cells have been shown to exhibit increased telomerase activity, which keeps the telomeres from shortening with divisions and the cancer cells from dying off.
Though he was awarded the Nobel Prize in 2009, Szostak’s work on telomeres and telomerase took place over twenty years earlier, in the early 1980s. Since then, he has moved on to studying RNA enzymes. Ultimately, his goal is to develop artificial recreations of cells and their processes that can be used for study in the lab.
Szostak credits his success to being open-minded and taking the time to talk to other researchers working on different sorts of projects. “On multiple occasions, I have been led into these new areas by talking to people working in fields quite different from mine,” he says. “The confluence of ideas from distinct fields seems to create a kind of intellectual turbulence that is both exciting and productive.”
Read Szostak’s popular article “Attempts to Define Life Do Not Help to Understand the Origin of Life“.