Tuesday, April 13, 2010

Lunch With a Laureate: Dr. Jack Szostak

Nobel Prizes are sometimes awarded years after the research leading to them was conducted. Often the awarded scientist has moved on to other areas of research. Such is the case with Dr. Jack Szostak, a genetics professor at Harvard Medical School and at Massachusetts General Hospital, who received the Nobel Prize in Physiology or Medicine in 2009 for research that he conducted in the 1980s. He won the Prize for his discovery of telomerase, an enzyme which is critical to the replication of DNA.

It turns out that DNA cannot be copied all the way to the end of the strand. So if we had nothing to protect the ends of our chromosomes, they would become smaller and smaller each time they replicate. Thankfully, shrinking chromosomes are avoided by a wonderful protective mechanism called a telomere. A telomere is a non-coding stretch of DNA at the end of a chromosome which protects the chromosome from losing important information each time it is copied. Because the telomere does not code essential information, it is okay that it is not fully replicated. However, if the telomeres were to get shorter and shorter each time DNA was copied, eventually the telomeres themselves would cease to exist and then there would be nothing protecting the important information from being deleted.

This is where Szostak's discovery, telomerase, comes into the picture. Telomerase maintains the length of the telomeres, ensuring that the protective cap at the end of our chromosomes remains strong. It turns out that telomerase is involved in the processes of aging and cancer. When the telomerase breaks down, genes are not copied well, causing aging. Hyperactive telomerase has been shown to be responsible for the rapidly multiplying cells of cancer. The discovery of telomerase is so important that it was even in my introductory biology textbook.

In the almost thirty years since Szostak made his discovery of telomerase, he has moved on to other areas of research. Currently, he is intrigued by how a bunch of chemicals turned into the beginning of life billions of years ago. His lab is developing an artificial cell that can undergo Darwinian evolution, modeling the early development of life. Szostak's model of the evolutionary cell consists of two self-replicating parts: the genetic material inside the cell, and the membrane enclosing the cell. The genetic material needs to allow the current cell to be copied, but it must also allow for variations to evolve into their own unique cells. This research is exciting, as it will allow us to better understand the early stages of life by seeing evolution in action. Szostak also hopes that his research on early cells will further our understanding of how cells work today.

You can meet Jack Szostak on Wednesday, April 28th at the MIT Museum as part of the weeklong Lunch With a Laureate series. He'll be available between 12 Noon and 1pm for an informal discussion about his life, his work, the Nobel Prize, and anything else you want to ask him. Bring your questions about telomerase, cells, aging, and the origin of life. Also, don't forget to bring your lunch!

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