The Nobel Prize in Physiology or Medicine 2001     

Tim Hunt

Tim Hunt,
born 1943.
Imperial Cancer Research Fund, Clare Hall Laboratories,
South Mimms, UK.


Tim Hunt discovered cyclins, proteins that bind to the CDK molecules. Cyclins regulate the CDK activity and select the target proteins to be phosphorylated. The proteins were named cyclins because of their cyclic variation in amount during the cell cycle (figure bottom left). Hunt's discovery that cyclins were degraded during mitosis turned out to be another fundamental control mechanism in the cell cycle.

Tim Hunt discovered the first cyclin molecule in 1982, using eggs from sea urchin, Arbacia, as a model system. He also found that cyclins, like CDK, were conserved during evolution. Today around ten different cyclins have been found in humans.




 The fundamental molecular mechanisms controlling the cell cycle are highly conserved through evolution and operate in the same manner in yeasts, insects, plants, animals and humans.
Cyclins are proteins formed and degraded during each cell cycle. Periodic protein degradation is an important control mechanism of the cell cycle. (D = cell division.)
| The Nobel Prize in Physiology or Medicine 2001 | Introduction | Leland HartwellPaul Nurse |
Tim Hunt
| The Implication of the Discoveries |
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Based on materials from the 2001 Nobel Poster for Physiology or Medicine
Nobel Poster from the Nobel Committee for Physiology or Medicine, web adapted by Nobel Web

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