By DAVID WILLIAMSON
UNC-CH News Services
CHAPEL HILL - Research on "whiskered" fruit flies containing proteins named after Groucho Marx has uncovered part of the way signaling mechanisms inside cells control what genes produce during normal development.
Because fruit flies and vertebrates, including humans, use essentially identical signals, the findings are a new and likely important step toward understanding how people and animals develop, scientists say. They also could help explain what goes wrong when cancer cells reproduce wildly and contribute to therapies that might reverse that deadly growth.
The research, conducted at the University of North Carolina at Chapel Hill and elsewhere, shows.
Groucho proteins and another family of proteins called Tcf interact to repress cells' internal signaling activity. That activity determines which genes are turned on, thus selecting what internal machinery cells will make. Normally, the process then informs cells what their role in life will be -- whether they will become part of an arm, for example, or part of a kidney.
"If the signaling pathway we are working on, which in fruit flies is called the 'wingless' pathway, is turned on continuously in humans in any of a variety of cell tissues such as in the colon, prostate or brain, that's the first step toward tumor development," said Dr. Mark Peifer, associate professor of biology at UNC-CH. "Our new work, aimed at learning in detail how genes get turned on and turned off normally, shows the process of controlling signals is a step more complicated than we thought.
"In a series of experiments, we found that Groucho and Tcf proteins act
together to turn genes off like a light switch," Peifer said. "We already knew
from earlier studies that we and others have done that Tcf proteins, when acting
with another molecule called 'Armadillo,' turn genes on. Our hypothesis is that
something very similar is happeni
Contact: David Williamson
University of North Carolina at Chapel Hill