Cellular "Suicide Weapon" Discovered

An enzyme that acts as the "weapon" with which cells "commit suicide" has been discovered by an Institute team led by Prof. David Wallach of the Membrane Research and Biophysics Department. The finding may lead to treatments for autoimmune disorders caused by abnormal cellular self-destruction, such as juvenile diabetes or multiple sclerosis.

"We've identified a crucial step in the self-annihilation of cells and may now be able to control this process," Wallach says.

All cells have a normal ability to "commit suicide" when they become redundant, but in certain diseases the immune system erroneously commands healthy cells to do so. In these disorders, a cell receives the suicide message through receptor molecules known as Fas/Apo-1 and through tumor necrosis factor receptors.

Wallach's team has now discovered the "weapon" that translates this message into action: an enzyme they call MACH. This enzyme cuts up vital proteins inside a cell, disrupting the cell's normal functions and killing it. The team has also found that the suicide message is transmitted with surprising directness. Unlike many other cellular processes that involve multiple stages, this one goes directly from the receptor to the enzyme.

The new understanding may make it possible to block the suicide mechanism when it causes disease.