July 6, 2012
Stop And Go
℠Traffic policeman´ protein directs crucial step in cell division
A traffic policeman standing at a busy intersection directing the flow of vehicles may be a rare sight these days, but a similar scene appears to still frequently play out in our cells. A protein called Lem4 directs a crucial step of cell division by preventing the progress of one molecule while waving another through, scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have found.
“This happens in both human cells and in the worm C. elegans, so it seems to be a strategy which evolved long ago,” says Iain Mattaj, director-general of EMBL, who led the work.
Through a combination of genetics and biochemical studies, the scientists found that, even though the worm version of Lem4 is markedly different from the human version, both perform the same double task at the end of cell division. Mattaj and colleagues suspect that this tactic — having a single molecule that prevents tags being added and simultaneously promotes their removal — could be employed in the many cellular processes that involve phosphate tags, such as the growth and division of cells or transmitting signals into cells from the environment.
It would now be interesting to investigate just what prompts Lem4 to start its double-action at the right moment, they say.
On the Net: