CAMBRIDGE, Mass. Since the 1990s, a green fluorescent protein known simply as GFP has revolutionized cell biology. Originally found in a Pacific Northwest jellyfish, GFP allows scientists to visualize proteins inside of cells and track them as they go about their business. Two years ago, biologists who discovered and developed the protein as a laboratory tool won a Nobel Prize for their work.
However, using GFP as a fluorescent probe has one major drawback the protein is so bulky that it can interfere with the proteins it's labeling, preventing them from doing their normal tasks or reaching their intended destinations.
"For a long time, people have been trying to find better ways to label proteins," says Katharine White, an MIT graduate student in the lab of Alice Ting, associate professor of chemistry.
Ting, White and their colleagues have now come up with a new way to overcome the disadvantages of GFP, by tagging proteins with a much smaller probe. Their probe allows proteins to carry out their normal functions, offering scientists the chance to glimpse never-before-seen activity.
The researchers describe the new technique, dubbed PRIME (PRobe Incorporation Mediated by Enzymes), in the Proceedings of the National Academy of Sciences this week.
First isolated from a jellyfish in 1962, GFP allows scientists to track otherwise invisible proteins as they move about the cell, orchestrating processes such as cell division and metabolism. To achieve this, scientists tack the gene for GFP onto the gene for the protein they want to study. After the engineered gene is introduced into cells, it will produce proteins that glow fluorescent green.
However, GFP's large size (238 amino acids) can interfere with some proteins, such as actin, a molecule that helps give cells their structure and is involved in cell division, motility and communication with other cells.
"People use fluorescent proteins to st
|Contact: Jennifer Hirsch|
Massachusetts Institute of Technology