STOCKHOLM, Sweden (AP) - Two Americans and one Japanese won the Nobel Prize in chemistry on Wednesday for the discovery and development of a brightly glowing protein first seen in jellyfish, work that has helped scientists study how cancer cells spread.
Japan's Osamu Shimomura and Americans Martin Chalfie and Roger Tsien shared the prize for their research on green fluorescent protein, or GFP, the Royal Swedish Academy of Sciences said.
The protein is a widely used laboratory tool to illuminate processes in living organisms, such as development of brain cells or the spread of cancer cells.
Shimomura first isolated GFP from a jellyfish found off the west coast of North America in 1962 and discovered that it glowed bright green under ultraviolet light.
In the 1990s, Chalfie showed GFP's value "as a luminous genetic tag," while Tsien contributed "to our general understanding of how GFP fluoresces," the academy said in its citation.
It said that their work has enabled "scientists to follow several different biological processes at the same time."
That means that researchers have been able to use GFP to track nerve cell damage from Alzheimer's disease or see how insulin-producing beta-cells are created in the pancreas of a growing embryo.
"In one spectacular experiment, researchers succeeded in tagging different nerve cells in the brain of a mouse with a kaleidoscope of colors," the citation said.
Shimomura, born in 1928, works at the Marine Biological Laboratory in Woods Hole, Massachusetts, and the Boston University Medical School.
Chalfie, born in 1947, is a professor at Columbia University in New York, while Tsien, born in 1952, is a professor at the University of California, San Diego.
The trio will split the 10 million kronor (US$1.4 million) award.
Shimomura began his work in the mid 1950s while still in Japan. In 1962, he was able to isolate a protein from jellyfish that was slightly greenish in the sunlight. In the 1970s, he showed that the protein, GFP, contained a chemical group that absorbed and emitted light.
In 1988, Chalfie heard about the protein and decided it would be an excellent tool for mapping the roundworm, acting as a glowing green signal for various activities in the roundworm's cells. He and others were able to prove that no other proteins were needed to control the chemical production to create the glowing green in GPF.
Tsien's work helped extend GFP's usefulness by adding more colors to the palette that glowed longer with more intensity, the academy said.
By exchanging various amino acids in different parts of GFP, he was able to get it to absorb and emit different colors, including blue, cyan and yellow.
"That is how researchers today can mark different proteins in different colors to see their interactions," the academy said in its citation.
The winners of the Nobel Prizes in medicine and physics were presented earlier this week. The prizes for literature, peace and economics are due to be announced Thursday, Friday and Monday.
The awards include the money, a diploma and an invitation to the prize ceremonies in Stockholm and Oslo on Dec. 10, the anniversary of prize founder Alfred Nobel's death in 1896.