Overview of signal transduction

Receptor- and ion channel-coupled signal transduction mechanisms are downstream communication processes used by regulatory molecules to modulate the essential cell processes of growth, differentiation and survival. Knowledge of signal transduction processes has dramatically increased in the past decade, and the basic principles of intracellular signaling are now quite well established. Cell signaling in higher organisms is a major, highly complex, phenomena that occupies a central position in current biomedical research. The complex machinery of intracellular signaling also has the potential to provide a wealth of novel drug discovery targets, from protein kinases, adaptor proteins, lipases, and cytoskeletal proteins, to nuclear effectors. This overview describes common features of cellular signaling pathways, including their interactions and responses to environmental stimuli. In particular, the overview focuses on the regulation of signaling pathways by protein functional-domain interactions as well as the intracellular proteins that mediate signal transduction.