Structural basis for positive allosteric modulation of AMPA and kainate receptors. (18th May 2021)

• Record Type: Journal Article
• Authors: Frydenvang, Karla; Pickering, Darryl S.; Kastrup, Jette Sandholm
• Is Part Of: Journal of physiology. Volume 600:Number 2(2022)
• Page Start: 181
• Page End: 200
• Publication Date: 2021-05-18
• Subjects: GluA2 -- GluA3 -- GluK1 -- ionotropic glutamate receptors -- positive allosteric modulators; Physiology -- Periodicals; 612.005
• DOI: 10.1113/JP280873
• Languages: English
• ISSNs: 0022-3751

Abstract

Abstract: This paper summarizes the present knowledge on how positive allosteric modulators (PAMs) interact with the ligand‐binding domain (LBD) of AMPA and kainate receptors, based on structure determinations. AMPA and kainate receptors belong to the family of ionotropic glutamate receptors that are responsible for mediating the majority of fast excitatory neurotransmission. These receptors have been related to brain disorders, e.g. Alzheimer's disease and attention deficit hyperactivity disorder. PAMs are small molecules that potentiate AMPA and kainate receptor currents by interfering with receptor desensitization. Therefore, PAMs are considered to be of interest for the development of pharmacological tools. Whereas PAMs for AMPA receptors have been known for several years, only recently have PAMs for kainate receptors been reported. Today, >80 structures are available for AMPA receptors with PAMs. These PAMs bind at the interface between two LBD subunits in the vicinity of residue 775, which is important for functional differences between flip and flop isoforms of AMPA receptors. PAMs can be divided into five classes based on their binding mode. The most potent PAM reported to date belongs to class 3, which comprises dimerized PAMs. Three structures of the kainate receptor GluK1 were determined with PAMs belonging to class 2. One PAM enhances kainate receptor currents 5‐ to 59‐fold but shows 100‐fold lower potency compared to AMPA receptors. Selective PAMs for kainate receptors will be of great use as pharmacological tools for functional investigations in vivo and might potentially prove useful as drugs in controlling the activity of neuronal networks. Abstract : Abstract figure legend AMPA and kainate receptors belong to the family of ionotropic glutamate receptors that are responsible for mediating the majority of fast excitatory neurotransmission. This review focuses on positive allosteric modulation of AMPA and kainate receptors and what we have learned from the >80 structures reported so far in the Protein Data Bank.