Professor Sir Paul Nurse, FRS, who with two colleagues, was awarded the Nobel Prize in Physiology or Medicine in 2001, will deliver a public lecture entitled "Controlling the Cell Cycle," at 8.00 p.m., Friday 28 March 2003, in the O'Flaherty Theatre, NUI Galway.

Director of Cancer Research UK, Paul Nurse, identified, cloned and characterized with genetic and molecular methods, one of the key regulators of the cell cycle, CDK (cyclin dependent kinase). CDK drives the cell through the cell cycle by chemical modification (phosphorylation) of other proteins.

All organisms consist of cells that multiply through cell division. An adult human being has approximately 10,000 billion cells (or 10 trillion cells), all originating from a single cell, the fertilized egg cell. In adults there is also an enormous number of continuously dividing cells that replace dying cells.

Before a cell can divide it has to grow in size, duplicate its chromosomes and separate the chromosomes for exact distribution between the two daughter cells. These different processes are coordinated in the cell cycle.

Nurse and his colleagues, Timothy Hunt and American scientist, Leland Hartwell, made seminal discoveries concerning the control of the cell cycle. They identified key molecules that regulate the cell cycle in all eukaryotic organisms, including yeasts, plants and animals.

These fundamental discoveries have a great impact on all aspects of cell growth. Defects in the regulation of the cell cycle may lead to the type of uncontrolled proliferation observed in cancer cells. Understanding this process may open new possibilities for cancer treatment. In October 2001, Nurse, Hunt and Leland were awarded the Nobel Prize for their discoveries of "Key Regulators of the Cell Cycle."

Using yeast as a model system, Paul Nurse's 'eureka moment' came when he discovered the gene CDC2, which has a key function in the control of cell division. In 1987 Nurse isolated the corresponding gene in humans, and it was later given the name CDK1 (cyclin dependent kinase 1). Nurse showed that activation of CDK1 is dependent on reversible phosphorylation, i.e. that phosphate groups are linked to, or removed from, proteins. On the basis of these findings, half a dozen different CDK molecules have been found in humans.

Nurse was not born with the proverbial 'silver spoon' in his mouth. Brought up in London, where his father worked as a mechanic and his mother as a part-time cleaner, he attended Harrow Grammar School where his classmates came from far more privileged backgrounds. Although naturally gifted at science subjects, Nurse failed O-Level French, thus preventing entry to University. However, an enlightened professor at Birmingham University recognised his talent and arranged entry for the brilliant young student to the School of Biology.

"Apart from being a fantastic scientist, Paul has a tremendous sense of humour, which makes him great company", says Professor Noel Lowndes, of NUI Galway's Department of Biochemistry, who was a colleague of Nurse's for some years at Cancer Research, UK. " He is a child of the Sixties who threw himself into the radical student politics of the time." Even now, Nurse retains that spirit of adventure. The man, with a passing facial resemblance to the actor Robin Williams, can be seen in the environs of Cancer Research UK, weaving in and out of traffic on his 500cc gleaming Kawasaki, purchased with the proceeds of the Nobel Prize.

Information from: Máire Mhic Uidhir, Press Officer, NUI Galway. Tel. 091-750418; 087-2986592