Cellular systems can be represented in “wiring diagrams” analogous to those of electronic circuits. But the components in the diagram are proteins, nucleic acids, and other biologically active molecules while the wires are interactions among those components.

Lucy Shapiro’s laboratory at the Stanford University School of Medicine chose a simple organism, a bacterium called Caulobacter crescentus, and set out to understand all the integrated processes that this organism needs to function as a living cell. Among these processes are the biochemical circuits that control cell division and differentiation. Four proteins serve as master regulators of these processes, Shapiro and her colleagues have found. Rising and falling quantities of these proteins in particular parts of the cell produce “an exquisite coordination of events in a three-dimensional grid.”

Building these circuit diagrams has allowed researchers to identify nodes that control cellular functions and are attractive targets for drugs designed to alter the functioning of cells. Research in Shapiro’s lab, for example, has led to drug development projects for two new antibiotics and an antifungal agent.

Shapiro’s lab members are about half biologists and half physicists and engineers. Each has had to learn the language of the others so that they can work together. “You put all these people together and amazing things happen,” Shapiro says. “Now we understand in a completely different way how this bacterial cell works.”

SOURCE: Shapiro Lab, Stanford University School of Medicine.