CHAPEL HILL - Most people probably think that most cells in the body -- not counting blood cells -- stay in one place their entire lives just as whole plants do, but nothing could be further from the truth.
These microscopic living structures move a little or a lot, healing wounds, developing embryos, scouting and attacking disease-causing invaders and, sometimes, spreading cancer. As a result, the mechanics and chemistry of how cells get themselves from one place to another fascinates researchers around the world.
Now, using a beam of laser light only a few microns in diameter, University of North Carolina at Chapel Hill scientists have succeeded for the first time in getting such light to alter the course of a moving cell. They have accomplished that by having the laser create active proteins from what are called "caged" proteins that they introduced into the cell.
A report on the research appears in the May 28 issue of the Journal of Cell Biology.
The work has begun attracting attention from other scientists internationally.
"We put caging groups on particular amino acids of the protein we were interested in inside single cells and that makes the proteins less active," said Dr. Kenneth A. Jacobson, professor of cell and developmental biology at the UNC School of Medicine. "Then we directed the laser beam into part of the cells to break the bond between the caging group and the amino acid so that the protein became active again. Afterward, depending on where we shined the light, cells turned by as much as 90 degrees."
Their experiments might be likened to putting the breaks on one rear wheel of a car so that the car would tend to pull to one side or another, Jacobson said.
Besides Jacobson, UNC authors are Drs. Partha Roy, a postdoctoral fellow soon to join the research faculty, and Zenon Rajfur, research associate. Drs. Gerard Marriott and Leslie Loew of the universities of Wisconsin and Connecticut, respectively,
Contact: David Williamson
University of North Carolina at Chapel Hill