CALCINEURIN REGULATION OF SYNAPTIC FUNCTION - FROM ION CHANNELS TO TRANSMITTER RELEASE AND GENE-TRANSCRIPTION

Calcineurin is a calcium (Ca2+)/calmodulin (CaM)-dependent protein pho sphatase that has been shown to regulate the activity of ion channels, neurotransmitter and hormone release, synaptic plasticity and gene tr anscription. At glutamatergic synapses, the inhibition of calcineurin with immunosuppressant drugs has been reported to enhance both the pre synaptic release of glutamate and postsynaptic responsiveness. Several other ligand- and voltage-gated ion channels are negatively regulated by calcineurin. Hormone release in insulin-secreting pancreatic beta cells and pituitary corticotrope tumour (AtT20) cells is also negative ly regulated by calcineurin. In this article, Jerrel Yakel discusses t he evidence that calcineurin plays a vital role in regulating neuronal excitability and hormone release.