Term | Definition |
Signal Transduction | Conversion of an impulse or stimulus from one physical or chemical form to another; the process by which a cell responds to an Extracellular signal |
4 types of cell signaling | paracrine, endocrine, autocrine, direct |
paracrine | Occurs between local cells where quick responses only last a short time |
endocrine | Occurs between distant cells mediated by hormones that travel to target cells producing a slower long lasting response |
autocrine | Produced by signaling cells that can bind to the ligand that is released |
direct | Occurs by transferring signals across the gap junction between neighboring cells |
Functions of intracellular signaling pathways | Relay, amplify, integrate, distribute |
3 classes of cell surface receptors | Ion-channel-coupled, G-Protein-coupled, Enzyme-coupled |
Ion channel coupled | Change the permeability of the plasma membrane to select ions altering the membrane potential and producing an electric current |
G Protein | Activate membrane bound GTP binding proteins which activate or inhibit an ion channel in the plasma membrane |
Enzyme coupled | The binding of an Extracellular ligand causes enzymatic activity on the intracellular side of the membrane |
Map-kinase signaling module | A set of 3 protein linked kinases that allow the cell to respond to Extracellular signals that stimulate proliferation |
Molecular switch | Intracellular signaling protein that toggles between an active and inactive state in response to receiving a signal |
Cyclic AMP (cAMP) | Intracellular signaling molecule generated from ATP in response to hormonal stimulation of cell surface receptors |
Calmodulin | Ca+ binding protein that modifies the activity of many target proteins in response to changes in Ca+ concentration |
Ras | One of a large family of small GTP binding proteins that help relay signals from cell surface receptors to the nucleus |
RTK (receptor tyrosine kinase) | Enzyme coupled receptor in which the intracellular domain has a tyrosine kinase activity that is activated by ligand binding to the receptors Extracellular domain |