All cells use signaling networks to process information and respond appropriately to rapidly changing environments. The structure of these networks varies widely across evolution: eukaryotes, like humans, tend to have incredibly complex networks, with abundant "crosstalk" between particular inputs and the set of possible downstream responses. Bacteria, on the other hand, have very simple signaling networks, with almost no crosstalk.
Recent research from the Deeds lab in the Center for Bioinformatics at KU has shed light onto the evolutionary pressures that have shaped these widely divergent architectures. In 2012, they published a paper in Biophysical Journal showing that the basic "building blocks" of eukaryotic signaling networks readily allows for the evolution of crosstalk between the kinases and phosphatases in the network. The Deeds lab recently published a paper in the Proceedings of the National Academy of Sciences USA showing that the building blocks of bacterial signaling networks behave quite differently, and cannot tolerate a large number of crosstalk interactions. Using a combination of mathematical models and an extensive analysis of bacterial genome sequences, they showed that this inherent feature of bacterial signaling motifs has had a dramatic influence on the evolution of protein interactions and interfaces in a wide variety of species.
To learn more about this work, see the PNAS article itself or read the KU today article entitled "Research reveals evolution of signaling networks in diverse organisms."