PMID: 30122377

Authors:

Twomey EC, Yelshanskaya MV, Vassilevski AA, Sobolevsky AI

Title:

Mechanisms of Channel Block in Calcium-Permeable AMPA Receptors.

Journal:

Neuron. 2018 Aug 9. pii: S0896-6273(18)30625-1. doi:, 10.1016/j.neuron.2018.07.027.

Abstract:

AMPA receptors mediate fast excitatory neurotransmission and are critical for CNS development and function. Calcium-permeable subsets of AMPA receptors are strongly implicated in acute and chronic neurological disorders. However, despite the clinical importance, the therapeutic landscape for specifically targeting them, and not the calcium-impermeable AMPA receptors, remains largely undeveloped. To address this problem, we used cryo-electron microscopy and electrophysiology to investigate the mechanisms by which small-molecule blockers selectively inhibit ion channel conductance in calcium-permeable AMPA receptors. We determined the structures of calcium-permeable GluA2 AMPA receptor complexes with the auxiliary subunit stargazin bound to channel blockers, including the orb weaver spider toxin AgTx-636, the spider toxin analog NASPM, and the adamantane derivative IEM-1460. Our structures provide insights into the architecture of the blocker binding site and the mechanism of trapping, which are critical for development of small molecules that specifically target calcium-permeable AMPA receptors.