Fig. 4

Host signaling and the stress response as a F. tularensis virulence factor target. F. tularensis proteins target a large number of host proteins involved in signaling (red and blue octagons) and the stress response (yellow diamond). Using the connectivity and Gene Ontology (GO) annotation, we identified two statistically significant signaling interaction modules, one containing eight host proteins and one containing five host proteins (shaded area). The larger one contains proteins related to the immune system response, whereas the smaller one contains proteins related to intracellular signaling. Further annotation assessment of proteins from the largest connected component (LCC) revealed additional proteins associated with signaling (blue octagons) and existing interaction modules. These results suggest that F. tularensis targets host proteins involved in signaling to interfere with cell-to-cell signaling and the immune response but also points toward PPIs among these host proteins as equally important targets