Today, the Howard Hughes Medical Institute celebrates three visionary scientists—Osamu Shimomura of the Marine Biological Laboratory, Martin Chalfie of Columbia University, and Roger Tsien, an HHMI investigator at the University of California, San Diego—who had the tenacity to follow that notion to its realization. Their perseverance in asking “what if” and extending the limits of what is visible have helped others make remarkable discoveries about how the biological world works. The three were honored in December 2008 with the Nobel Prize in Chemistry for the discovery and development of green fluorescent protein, or GFP, a research tool that has revolutionized the biological sciences.
GFP once existed only in nature’s laboratory. It remained hidden inside the gossamer “umbrella” that girds the jellyfish A. victoria. The path to GFP began in 1962 with Shimomura’s identification of the GFP protein, but it wasn’t until 1984 that Douglas Prasher, a scientist at the Woods Hole Oceanographic Institution, cloned the GFP gene. Two years later, Prasher and Chalfie demonstrated that GFP could be used as a marker for gene expression.
The Story of GFP
The Nobel Foundation recognized Tsien for his work developing GFP markers to watch proteins in action. By manipulating genes from the glowing jellyfish and from corals, Tsien created a set of genes that produce a dazzling array of hues, including cherry, strawberry, tangerine, tomato, orange, banana, and honeydew. These genes allow scientists to tag any of the tens of thousands of proteins at work in the body to observe what they do and, by marking multiple proteins, how they interact.
Today, fluorescent proteins are so ubiquitous that scientists can order them through various catalogs. And GFP’s utility goes far beyond human biology as well; it’s been used to create bacteria that glow in the presence of arsenic, a significant problem in well water in Southeast Asia, and to identify explosives such as TNT.
As Tsien has noted with a certain degree of admiration, A. victoria is a born chemist. Its dazzling iridescent light shows are the product of feats no human chemist can match. “A single jellyfish gene directs 238 ordered condensations, plus one cyclization, plus one oxidation,” Tsien stated in his Nobel speech in Stockholm on December 10, 2008. “It’s all done in a few minutes … with only one slightly toxic byproduct and an essentially 100 percent yield of an extremely useful product that literally glows green.”