Sir Tim Hunt

Nobel Prize in Physiology or Medicine


Look inside your body and you’ll find millions of cells dividing every second, replacing themselves to keep you healthy. In the 1980s, Tim Hunt discovered that this highly regulated process is controlled by a family of proteins which he named cyclins, after both their behaviour and his love of cycling. 

In 1982, Tim Hunt was studying the development of fertilised sea urchin eggs when he noticed that one of their proteins vanished every time the eggs’ cells divided, only to return, build up and then disappear again during the next division. “I knew that I had stumbled upon something important, because proteins don’t just disappear like that,” he has said.

This protein turned out to control the cells’ growth, duplication and division. Tim Hunt and his students went on to discover cyclins in clams, starfish and frogs, and they were soon found in human beings, too. Working with other scientists, he determined that the cyclins’ destruction allowed cells to proceed into the next phase of the cell cycle, acting like a “go” signal. 

In 2001, Tim Hunt and two other scientists, Lee Hartwell and Paul Nurse were awarded the Nobel Prize in Physiology or Medicine for their discovery of “Key regulators of the cell cycle”. It turned out that cyclins have partners, discovered by Tim Hunt’s fellow laureates. It is the combination of the two, the cyclin-dependent protein kinases or CDKs, that catalyse cell cycle transitions. The prize committee noted that “most biomedical research areas will benefit from these discoveries, which may result in broad applications within many different fields”. 

For example, increased levels of certain CDKs have been found in human tumours, including breast cancer and brain tumours, so Tim Hunt’s discovery could be used for tumour diagnosis, and recently, inhibitors of a particular cyclin-dependent protein kinase have shown promise in the treatment of breast cancer. 

Tim Hunt himself spent two decades investigating why cells turn cancerous. From 1990 to 2010, he was a principal scientist at the Cancer Research UK charity (formerly called the Imperial Cancer Research Fund). 

While he retired in 2010, Tim Hunt now has an office in Japan’s Okinawa Institute of Science and Technology (OIST), where he teaches occasionally. He continues to write problems for ‘Molecular Biology of the Cell’ and is busy converting ‘The Problems Book’, which he co-wrote, into a computer-based ‘formative assessment’ platform with multiple choice questions. 

Today, cyclins are featured in high school biology textbooks all over the world. For his contributions to the field of biology, Tim Hunt was knighted in Britain in 2006 and received a Medal from the U.K. Royal Society that same year. He continues to be an Emeritus Scientist at the Francis Crick Institute in London, U.K., and sits on several scientific councils and committees.