NEU 301 Lecture Notes - Lecture 19: Cell Adhesion Molecule, Signal Transduction, Cell Signaling
Document Summary
Receptors are specific to a given signal: name the three types of signals and what receptors they act on. Cell-impermeant molecules - (ex: most neurotransmitters) ionotropic and metabotropic receptors. Cell permeant molecules - (ex: cholesterol derived hormones) intracellular receptors. Receptors that have direct contact with the pre-synaptic cell. Channel-linked receptors: signal molecule binds directly to channel, opens channel, ions flow through. Enzyme-linked receptors: signal molecule binds, activates enzyme, enzyme generates product. G-protein coupled receptors: signal molecules bind, g-protein binds to receptor, g- protein is activated. Intracellular receptors: signaling molecule cross post-synaptic membrane and binds to intracellular receptor, activates receptor, receptor regulates transcription. They are metabotropic receptors consisting of 7 transmembrane domains. 2, 3, 6, and 7 make up the neurotransmitter binding region. G-proteins bind to both the loop between domains 5 and 6 and the c-terminus. Rgs proteins (regulators of g-protein signaling, aka gaps) stimulate gtp hydrolysis via gtpases.
