The Nobel Prize in Physiology or Medicine 2001     

Paul Nurse

Paul Nurse,
born 1949.
Imperial Cancer Research Fund, Lincoln's Inn Fields, London, UK.

Paul Nurse identified the key regulator of the cell cycle, the gene cdc2, during the years 1976-80. He showed that the product of this gene controls cell division (transition from G2 to M). Nurse discovered the gene cdc2 in the fission yeast Schizosaccharomyces pombe. He later showed that cdc2 had the same function as the gene CDC28 in the distantly related baker's yeast.

Thus, cdc2 has more than one function in the cell cycle, controlling both the transition from G1 to S and G2 to M. In 1987 Paul Nurse isolated the corresponding human gene, later called CDK1. These findings showed that the CDK function has been conserved through evolution.

The gene CDK1 encodes a protein that is a member of a family called cyclin dependent kinases (CDK). These molecules function by linking phosphate groups to other proteins (phosphorylation, figure to the left). Today half a dozen different CDK-molecules have been found in humans.

 CDK and cyclin together form an enzyme that activates other proteins by chemical modification (phosphorylation). The amount of CDK molecules is constant during the cell cycle, but their activities vary because of the regulatory function of the cyclins. CDK can be compared with an engine and cyclin with a gear box controlling whether the engine will run in the idling state or drive the cell forward in the cell cycle.
| The Nobel Prize in Physiology or Medicine 2001 | Introduction | Leland HartwellPaul Nurse |
Tim Hunt
| The Implications of the Discoveries |
Play the "Control of the Cell Cycle" game! 
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

Copyright © Nobel Media AB 2014