No, Tsien's group is not giving out fruit baskets; the names describe vibrant new varieties of fluorescent protein that the researchers have created to tag cells and observe a range of cellular processes.

By splicing the genes for the fluorescent proteins into specific genes in the cell, researchers can detect when those genes are switched on to produce proteins. They can then use the telltale fluorescent colors to separate the cells visually. The availability of the new colors will enable scientists to track the effects of multiple genetic alterations in a single cell.

Tsien and his colleagues at the University of California, San Diego, published a research article describing the new fluorescent proteins in the December 2004 issue of the journal Nature Biotechnology. Lead author on the paper was HHMI predoctoral fellow Nathan C. Shaner in Tsien's laboratory. In separate studies, Tsien's team "borrowed" the immune system's machinery for generating antibody diversity and used it to evolve a new red fluorescent protein.

In addition to offering fluorescent proteins in a range of distinctive colors, Tsien's group has improved their design, creating proteins that are "monomers" that consist of only single protein units. Fluorescent proteins found in nature with yellow to red colors are invariably four-unit agglomerations that are often toxic or disruptive when fused to proteins that scientists hope to track.

"The analogy is that if you have a detective who is supposed to be tracking suspects, and that detective has to go around in groups of four
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Contact: Jim Keeley
keeleyj@hhmi.org
301-215-8858
Howard Hughes Medical Institute
22-Dec-2004