The multi-layered structure of SignaLink 2. Layers are from different sources and contain different types of interactions. The image of an onion is used to illustrate this structure. The core of the database contains the interactions between pathway member proteins. In the first layer these proteins are connected with pathway regulators, such as scaffold and endocytotic proteins. The next two layers contain the first neighbor interactors of these proteins. The interactors have a predicted enzymatic effect (second layer) or a known physical interaction (third layer) to the members of the core or the first layer. The fourth and the fifth layers contain the transcription factors (TFs) and miRNA regulators of the already listed proteins, respectively. The fifth layer also contains the TFs of these miRNAs.
Fazekas et al. BMC Systems Biology 2013 7:7 doi:10.1186/1752-0509-7-7