# Single-particle cryo-EM characterization of AMPA receptor functional states

> **NIH NIH R01** · COLUMBIA UNIVERSITY HEALTH SCIENCES · 2021 · $374,088

## Abstract

PROJECT SUMMARY
AMPA-subtype ionotropic glutamate receptors, which mediate fast signaling between neurons and contribute
to high cognitive processes, are also implicated in numerous neurological diseases, including Alzheimer's
disease, amyotropic lateral sclerosis, epilepsy and ischemia. The ability to regulate AMPA receptors is
therefore an important clinical goal. There is, however, an unmet need for drugs to regulate AMPA receptor
activity in pathological conditions that indicates a profound gap in our knowledge of AMPA receptor structure
and function. Our long-term goal is to understand how AMPA receptor molecular machinery works at the
atomic level. We plan to study AMPA receptor structure and function using advances in single-particle cryo-
electron microscopy (cryo-EM). Not only can modern cryo-EM reach similar or better resolution than X-ray
crystallography, it can also be used as a powerful tool to analyze heterogeneous populations of AMPA receptor
particles and extract structural information that belongs to each individual functional conformation. Because of
much more economic sample requirements, cryo-EM can also approach complexes of AMPA receptor with
transmembrane regulatory subunits, which are hard to produce in large quantities and demonstrate high
degree of conformational and stoichiometric heterogeneity and are thus intractable to X-ray crystallography.
Our Specific Aims are to (1) elucidate structural basis of AMPA receptor regulation by auxiliary subunits, (2)
determine molecular bases of AMPA receptor activation, and (3) establish molecular mechanism of AMPA
receptor desensitization. To reach our goals, we will use cryo-EM to obtain structures of rat GluA2 in complex
with different auxiliary subunits in the presence of competitive antagonists, agonists and/or positive allosteric
modulators. We will use Fluorescence-detection Size Exclusion Chromatography (FSEC) and thermostability
assays to assess protein expression, assembly, homogeneity and stability. We will also employ site-directed
mutagenesis and electrophysiological recordings to study functional mechanisms and to critically test our
structural models. Reaching our research goals will have a significant impact on understanding the
mechanisms of excitatory neurotransmission and will provide molecular-level knowledge essential to facilitate
design of new drugs to treat neurological diseases.

## Key facts

- **NIH application ID:** 10166967
- **Project number:** 5R01NS107253-04
- **Recipient organization:** COLUMBIA UNIVERSITY HEALTH SCIENCES
- **Principal Investigator:** Alexander Sobolevsky
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $374,088
- **Award type:** 5
- **Project period:** 2018-08-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10166967

## Citation

> US National Institutes of Health, RePORTER application 10166967, Single-particle cryo-EM characterization of AMPA receptor functional states (5R01NS107253-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10166967. Licensed CC0.

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