AMPA receptors: mechanisms of auxiliary protein action

AMPA receptors are the prime mediators of fast excitatory transmission in the brain. Auxiliary subunits directly interact with AMPA receptors, hustling them to synapses and fine-tuning their responses to glutamate in multiple ways. Recent structural and functional studies have clarified the scope of molecular interactions underlying AMPAR co-assembly with and modulation by auxiliary proteins. Complementary physiological and pharmacological work has expanded our view of what auxiliary proteins are capable of. Here we review how these studies advance a more refined outline of mechanisms of auxiliary protein action, but still leave some tantalizing parts of the puzzle missing.