"Although scientists understand how a given protein interacts with other proteins, the way they connect with each other as a whole remains mysterious," says Sergei Maslov, a physicist at the U.S. Department of Energy's Brookhaven National Laboratory, one of the study's two authors.
For the last 10 years, Maslov, an expert in statistical physics, has been studying complex systems such as collections of particles, proteins, and networked computers. In the new study, Maslov and physicist Kim Sneppen of the Norwegian University of Science and Technology used computer modeling to look at how proteins interact with each other.
Although scientists know that some proteins are very busy "talking" to many other proteins, Maslov and Sneppen discovered that such highly connected proteins are unlikely to "talk" to each other. To illustrate this intriguing phenomenon, Maslov uses the analogy of airline "hubs."
"Each airline company has a network of flights connecting different cities," he says. "But when a city serves as a hub for one company, the neighboring cities are mostly served by this company. Also, the hub is served mainly by this company and not by another big company. So the two big companies rarely 'talk' to each other."
The scientists think that proteins interact this way to reduce interference among the messages of proteins that crisscross each other in the cell. The other possible advantage of this protein interaction pattern is to make the protein network inside the cell more stable. "Proteins with many connections seem not to want to be disturbed by wrong messages or anything harmful' to thes
Contact: Karen McNulty Walsh
DOE/Brookhaven National Laboratory