Neto1 and Neto2: auxiliary subunits that determine key properties of native kainate receptors

Kainate receptors (KARs) are a subfamily of ionotropic glutamate receptors (iGluRs) that mediate excitatory synaptic transmission, regulate neurotransmitter release, and show a remarkably selective distribution in the brain. Compared to other iGluRs, the precise contribution of KARs to brain function is less understood. Unlike recombinant KARs, native KARs exhibit characteristically slow channel kinetics. The underlying explanation for this dissimilar kinetics has remained elusive until recently. New research has identified Neto1 and Neto2 as KAR auxiliary subunits that determine unique properties of synaptic KARs, including their slow kinetics and high affinity for agonist. Whether these auxiliary subunits regulate KAR trafficking and targeting at the synapse is less clear. By regulating channel gating, Neto1 and Neto2 can increase the diversity of KAR functional properties. These auxiliary subunits may represent a starting point for a better understanding of the role played by neuronal KARs under normal and pathological conditions, but also, they may provide an alternative target for the development of new drugs regulating KARs and brain function.