Signal transduction and drug development

Extracellular information is translated into the cellular responses by various signal transduction systems such as G protein-coupled receptor-linked and protein tyrosine kinase receptor-mediated pathways. The changes or modifications of theses signaling proteins cause uncontrolled transformation or cell death. One of the features of the signaling molecules is that these proteins contain the domains or motifs for protein-protein or protein-lipid interactions governed by several amino acids. Therefore, these amino acids may become promising targets for the drug design. In contrast with intracellular molecules, the receptors located on cellular surface are still the best candidate for the drugs. The future analysis of cellular signal transduction system allows us to develop new drugs that cannot cause serious side effects in future.