Isacoff said that this same photoswitch could be attached to a variety of proteins to push or pull them into various shapes, even making a protein bend in half like a tweezer.
In 2006, in a cover article in the new journal Nature Chemical Biology, the researchers described for the first time a re-engineered glutamate receptor that is sensitive to light, which complements the SPARK channel because the same color of light will turn one on while turning the other off.
"Now we have photochemical tools for an on switch and an off switch for nerve cells," Kramer said. "This will allow us to simulate the natural activity of the healthy retina, which has on cells and off cells that respond to light in opposite ways."
Isacoff, Kramer, Trauner and their colleagues are experimenting with other molecules that can force shape changes, looking for improved ways to attach shape-changing molecules to proteins, developing means to shuttle these photoswitches into cells, building artificial genes that can be inserted into a cell's DNA to express the photoswitches in the correct cell, and searching for ways to get light into areas of the body not possible to illuminate directly.
"I'm struck by how versatile this approach seems to be," Isacoff said, noting its applications for screening, diagnosing and treating disease. "I'm convinced that we'll come up with a therapy that will work in the clinic."