G protein-coupled receptors
Upon ligand binding, a conformational change activates a resting heterotrimeric G protein associated with the cytoplasmic leaf of the plasma membrane. Activation of a single receptor can result in 1, 10, or more active heterotrimeric G proteins, providing amplification as well as transduction of the first messenger.
are intracellular membrane proteins that help to regulate movement within the cell.
are plasma membrane proteins that couple the extracellular binding of primary signaling molecules to activation of small G proteins.
are plasma membrane proteins that couple the extracellular binding of primary signaling molecules to the activation of heterotrimeric G proteins.
are intracellular proteins that couple the binding of primary messenger molecules with transcription.