From Harvard Magazine:
Just about everything the body does depends on the interactions of proteins—the molecules encoded by genes that serve as the primary workers in cells. Without thousands of coordinating proteins, cells wouldn’t function properly; even subtle problems in these interactions can lead to disease.
Spyros Artavanis-Tsakonas, professor of cell biology at Harvard Medical School (HMS), believes that to better grasp what can go wrong with proteins, scientists need to understand how these molecules function together (not just in isolation) in healthy cells. In the October 28 issue of Cell, his team published a large-scale map that tracks the interactions of thousands of proteins in fruit flies (Drosophila melanogaster). Since then, the researchers have continued to expand the map and delve into these connections in more detail. The map was created through a painstaking process that Artavanis-Tsakonas compares to fishing. The scientists first randomly generated thousands of distinct proteins to serve as “bait,” and introduced these proteins into Drosophila cells. When they removed the baits, they could see which proteins had adhered to them, thanks to the application of a highly precise technique, mass spectrometry, carried out by HMS professor of cell biology Steven Gygi. The result: a vast “social network” of proteins.