Functional modulation of ligand-gated GABAA and NMDA receptor channels by phosphorylation.

Ion channels are ubiquitous membrane proteins that may be organized into different families according to their predicted transmembrane topology. They are concerned with rapid signalling over plasma and intracellular membranes and are activated, depending on their type, by transmembrane voltage, intracellular second messengers or extracellular neurotransmitters. Intracellular activities of protein kinases and phosphatases act to modulate ion channel activity. The modulation of the function of ligand activated, neuronal ion channels, that are crucial for synaptic transmission, may be an important basis for a modulation of a synaptic efficiency. The following review concentrates, due to space limitations, on the postranslational modification, and on the modulation of the function by protein kinase C and protein kinase A, of ligand-gated GABAA channels and NMDA channels on a molecular level.