A switch between life and death

August 28, 2006

The breakthrough came as Barry Thompson from Stephen Cohen's group at EMBL looked at a recently discovered signaling pathway called "Hippo."

"Hippo acts as a switch between cell division and death," says Barry Thompson, "If the pathway is too active, tissues overgrow because too many cells divide and too few die. But until now, we hadn't found a connection between the signals and the cellular machinery that drives growth."

Using sophisticated genetic techniques, Thompson and Cohen established that a small molecule, a microRNA called bantam, makes this link. Without bantam, tissues grow too slowly and remain smaller than normal. The amount of bantam produced by the cell directly depends on the amount of traffic on the Hippo signaling pathway, and higher levels of bantam prompt more cell division.

"Bantam is an unusual type of RNA molecule," Thompson says. "Normally, RNAs go on to make protein, but bantam is different. Its job is to regulate other RNAs by attaching itself to them; the result is that they block their expression into proteins. In this case, those proteins would go on to shut down cell division. With bantam around, the brake is off, and they continue to divide."

Cohen and his lab have been studying microRNAs like bantam for some time because of their important role in the regulation of many vital processes across species. The next step will be to identify the RNAs that bantam docks onto to control. This will provide a more complete view of the Hippo pathway and may provide insights into the central role it plays in tissue growth and cancers in humans and other organisms.
-end-
Published in the 25 August, 2006 issue of Cell.

European Molecular Biology Laboratory

Related Cell Division Articles from Brightsurf:

Cell division: Cleaning the nucleus without detergents
A team of researchers, spearheaded by the Gerlich lab at IMBA, has uncovered how cells remove unwanted components from the nucleus following mitosis.

Genetic signature boosts protein production during cell division
A research team has uncovered a genetic signature that enables cells to adapt their protein production according to their state.

Inner 'clockwork' sets the time for cell division in bacteria
Researchers at the Biozentrum of the University of Basel have discovered a 'clockwork' mechanism that controls cell division in bacteria.

Scientists detail how chromosomes reorganize after cell division
Researchers have discovered key mechanisms and structural details of a fundamental biological process--how a cell nucleus and its chromosomal material reorganizes itself after cell division.

Targeting cell division in pancreatic cancer
Study provides new evidence of synergistic effects of drugs that inhibit cell division and support for further clinical trials.

Scientists gain new insights into the mechanisms of cell division
Mitosis is the process by which the genetic information encoded on chromosomes is equally distributed to two daughter cells, a fundamental feature of all life on earth.

Cell division at high speed
When two proteins work together, this worsens the prognosis for lung cancer patients: their chances of survival are particularly poor in this case.

Cell biology: The complexity of division by two
Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have identified a novel protein that plays a crucial role in the formation of the mitotic spindle, which is essential for correct segregation of a full set of chromosomes to each daughter cell during cell division.

Better together: Mitochondrial fusion supports cell division
New research from Washington University in St. Louis shows that when cells divide rapidly, their mitochondria are fused together.

Seeing is believing: Monitoring real time changes during cell division
Scientist have cast new light on the behaviour of tiny hair-like structures called cilia found on almost every cell in the body.

Read More: Cell Division News and Cell Division Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.