Cell signaling is part of a complex communication system that governs basic cellular activities and coordinates cell actions including division, differentiation, metabolism and death. Research indicates errors in intracellular processing are responsible for diseases such as cancer, autoimmunity and diabetes.
The initiation of cell signaling pathways typically occurs when a cellular receptor binds cognate ligand. Subsequent pathway activation depends on the type of receptor activated by ligand binding. In some cases, ligand binding itself can result in transformational changes in the receptor whereas protein-to-protein interactions are induced as a result of a cellular receptor binding its cognate ligand. These protein-protein interactions are phosphorylation/dephosphorylation events that cascade associated signaling molecules through kinases and phosphatases. The mitogen-activated protein kinase pathways (MAPK) is one example that is known to alter cellular proliferation as a result of the downstream phosphorylation of signaling molecules.