Szostak, << SHAW stak, >> Jack William (1952-…), an English-born American biologist, shared the 2009 Nobel Prize in physiology or medicine for his work with telomeres. Telomeres are protective structures on the ends of chromosomes, the threadlike parts in cells that carry genetic (hereditary) information (see Telomere ). Szostak shared the prize with the American biologists Elizabeth H. Blackburn and Carol W. Greider.
Chromosomes carry genes, which are encoded in the structure of the genetic material DNA (deoxyribonucleic acid). Genes carry the chemical instructions that determine the form and function of each cell in an organism.
Szostak had observed that strands of DNA were rapidly degraded when he inserted them into dividing yeast cells. He later learned of Blackburn’s discovery that the end of each chromosome includes a particular highly repetitive sequence of DNA. This sequence occurs along with specialized proteins that form the telomere. Working together, Szostak and Blackburn extracted strands of telomere DNA from a single-celled organism and inserted them with other DNA into yeast cells. The biologists observed that the DNA was rapidly degraded, except for the parts that ended in telomeres. Thus, they demonstrated that telomeres form a protective “cap” at the ends of chromosomes. Scientists understand that cancer and other diseases associated with aging are marked by chromosome damage. By protecting the chromosomes, telomeres thus play an important role in preventing such disease.
Szostak was born in London on Nov. 9, 1952. His family later moved to Canada, where he graduated from McGill University in Montreal in 1972. He received his Ph.D. degree in biochemistry at Cornell University in Ithaca, New York, in 1977. After conducting research at Cornell, he joined the faculty of Harvard Medical School in Cambridge, Massachusetts, in 1979. He is currently professor in the department of genetics at Harvard and the department of molecular biology at Massachusetts General Hospital in Boston. His research focuses on the origins of life.
See also Blackburn, Elizabeth Helen ; Greider, Carol Widney .
