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Geneticist Jack Szostak Shares Nobel Prize in Physiology or Medicine


Jack Szostak

Jack Szostak

Courtesy of Massachusetts General Hospital

Professor of genetics Jack W. Szostak has won the Nobel Prize in Physiology or Medicine with Elizabeth H. Blackburn (University of California, San Francisco) and Carol W. Greider (Johns Hopkins School of Medicine). The three scientists were recognized for their work on how chromosomes are protected by telomeres and the enzyme telomerase. Szostak's home page at Harvard Medical School details his recent work on the synthesis of life on earth: "the related challenges of understanding the origin of life on the early earth, and constructing synthetic cellular life in the laboratory." His lab home page is here; he is also a Howard Hughes Medical Institute investigator, and  has a biographical page there, emphasizing his current work on the origins of life and the re-creation of the first steps in biological synthesis. Harvard's Origins of Life Initiative is described here; Szostak is one of the affiliated faculty members.

According to the Nobel press release, the trio have solved a critical part of a fundamental problem in biology: "how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation. The Nobel Laureates have shown that the solution is to be found in the ends of the chromosomes--the telomeres--and in an enzyme that forms them – telomerase."

The explanation continues:

The long, thread-like DNA molecules that carry our genes are packed into chromosomes, the telomeres being the caps on their ends. Elizabeth Blackburn and Jack Szostak discovered that a unique DNA sequence in the telomeres protects the chromosomes from degradation. Carol Greider and Elizabeth Blackburn identified telomerase, the enzyme that makes telomere DNA. These discoveries explained how the ends of the chromosomes are protected by the telomeres and that they are built by telomerase.

If the telomeres are shortened, cells age. Conversely, if telomerase activity is high, telomere length is maintained, and cellular senescence is delayed. This is the case in cancer cells, which can be considered to have eternal life. Certain inherited diseases, in contrast, are characterized by a defective telomerase, resulting in damaged cells. The award of the Nobel Prize recognizes the discovery of a fundamental mechanism in the cell, a discovery that has stimulated the development of new therapeutic strategies.