Work on biology's 'Guiding Star' wins Nobel Prize in Chemistry

Three US-based scientists have won the 2008 Nobel Prize in Chemistry for their work in identifying and manipulating the Green Fluorescent Protein (GFP). Professor Osamu Shimomura, of the Marine Biological Laboratory, Woods Hole, Massachusetts; Professor Martin Chalfie, of Columbia University, New York; and Professor Roger Tsien, of the University of California San Diego, will jointly receive the prestigious award of ten million Swedish Krona. Their collective efforts to understand GFP have been 'revolutionary to cell biology', and transformed understanding of genes, proteins, and whole tissues in living organisms.

Essentially a fluorescent flag, GFP can be unobtrusively attached to nearly any protein in the cell. When excited under blue light, GFP glows green. This striking phenomenon reveals the (often unexpected) whereabouts of the molecule it has been joined to.

The story started four decades ago, when Shimomura began to purify the protein from the jellyfish Aequorea Victoria, collected off the North West coast of North America. Later, in 1992, Professor Chalfie succeeded in cloning the gene for GFP and inserting it into bacteria. Since then, Professor Tsien has tinkered with the molecule's structure to enhance its brightness and make it available in a plethora of colours. Recent applications include visualising nerve growth in multicolour and watching the evolution of the AIDS (Acquired Immunodeficiency Syndrome) virus at the cell surface.

Sean Sweeney, a researcher in neurodegenerative disease at the University of York, UK, agrees to the importance of the protein. 'Previously the only way to study the developmental fate of cells was to be invasive-label cells with a dye and look at the dead, labelled tissue with a microscope. Now we can label them genetically with GFP and look at cells live, over time'.

The omission of one researcher has not gone unnoticed however. Douglas Prasher, also at Woods Hole, was the first to isolate the DNA sequence for GFP. Prasher searched for the gene for three years, and by the time he had a sequence in his hands the crucial experiment had been left undone - namely, successfully inserting the gene into the bacterium Escherichia coli. Piquing the interest of Professor Chaflie, Prasher sent the sequence to him, and the candidate gene was confirmed.

Prasher no longer works in science, but remains humble about the decision. 'If they're ever in Huntsville', he says of the three men whom he helped, 'they need to take me out to dinner'.