Reporting in the current issue of the journal Cell, the
scientists show that a protein called PTEN goes to the back of
the cell when a chemical attractant is sensed, allowing the cell
to move purposefully toward the attractant. Because PTEN "brings
up the rear," the molecules crucial for allowing the cell to
reach out and move forward are restricted to the front of the
cell. "How do cells determine which direction to go to find an
attractant? How do they sense the differences in concentration
of the chemical, alter their membranes and move forward?" asks
Peter Devreotes, Ph.D., professor and director of cell biology
in the school's Institute for Basic Biomedical Sciences. "It's a
very complex puzzle, and we've found another piece."
Postdoctoral fellow Miho Iijima, Ph.D., and Devreotes used
specially labeled versions of PTEN that glowed green to see
where the protein is in the cell during movement of living
amoeba. They also monitored the movement and sensing abilities
of amoeba whose PTEN gene was removed or