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Principal Investigator: Alexander Sobolevsky
Organization: COLUMBIA UNIVERSITY HEALTH SCIENCES
Fiscal Year: 2024
Award: $398,780
Funding agency: National Institute of Neurological Disorders and Stroke
PROJECT SUMMARY
AMPA-subtype ionotropic glutamate receptors mediate fast signaling between neurons and contribute to high
cognitive processes. Since AMPA receptors are also implicated in numerous neurological disorders, including
Alzheimer’s disease, amyotrophic lateral sclerosis, epilepsy, and ischemia, the ability to regulate them
represents an important clinical goal. However, there is an unmet need for drugs to regulate AMPA receptor
activity in pathological conditions, which highlights a profound gap in our knowledge of AMPA receptor
structure and function. Our long-term goal is to understand how AMPA receptor molecular machinery operates
at the atomic level. We plan to study AMPA receptor structure and function using single-particle cryo-electron
microscopy (cryo-EM). Advances in cryo-EM that were signified by the “resolution revolution” brought us a
number of AMPA receptor structures in different gating conformations and in complex with several small
molecules and regulatory proteins. Nevertheless, only a little fraction of AMPA receptor conformational states
and binding partners have been characterized structurally and the resolution of the reported structures remains
relatively low, limiting our ability to see the atomic details. We, therefore, plan to use cryo-EM advances to fill
up this knowledge gap and to focus on the following Specific Aims: (1) unravel structural principles of AMPA
receptor regulation by auxiliary subunits, (2) reveal molecular determinants of AMPA receptor activation and
conductance, and (3) determine molecular mechanisms of AMPA receptor desensitization. To reach our
research goals, we will use cryo-EM to obtain structures of AMPA receptors alone or in complex with different
auxiliary proteins, in the presence of agonists, competitive antagonists, positive or negative allosteric
modulators, and in conditions favoring various conformational states. 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 combined with single-channel and
whole-cell patch-clamp 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
the design of new drugs for the treatment of neurological disorders.
Terms: <AD dementia><AMPA Receptors><Address><Agonist><Alzheimer Type Dementia><Alzheimer disease dementia><Alzheimer sclerosis><Alzheimer syndrome><Alzheimer's><Alzheimer's Disease><Alzheimers Dementia><Amyotrophic Lateral Sclerosis><Amyotrophic Lateral Sclerosis Motor Neuron Disease><Architecture><Area><Assay><Binding><Binding Site Domain><Binding Sites><Bioassay><Biological Assay><Brain><Brain Nervous System><Cell Body><Cell Communication and Signaling><Cell Signaling><Cells><Clinical><Combining Site><Communication><Complex><Coupling><Cryo-electron Microscopy><Cryoelectron Microscopy><Crystallographies><Crystallography><DLG1><DLG1 gene><Detection><Discs Large, Drosophila, Homolog of, 1><Drug Design><Drugs><Electron Cryomicroscopy><Electrophysiology><Electrophysiology (science)><Encephalon><Engineering / Architecture><Epilepsy><Epileptic Seizures><Epileptics><Family><Fluorescence><Future><Gametes><Gehrig's Disease><GeneHomolog><Generations><Genes><Germ Cells><Germ-Line Cells><Glutamate Receptor><Glutamates><Goals><Homolog><Homologous Gene><Homologue><Individual><Intracellular Communication and Signaling><Ion Channel><Ionic Channels><Ischemia><Knowledge><L-Glutamate><Lateral Sclerosis><Length><Ligand Binding Domain><Lou Gehrig Disease><Mediating><Medication><Membrane><Membrane Channels><Molecular><Molecular Configuration><Molecular Conformation><Molecular Interaction><Molecular Sieve Chromatography><Molecular Stereochemistry><Nerve Cells><Nerve Impulse Transmission><Nerve Transmission><Nerve Unit><Nervous System Diseases><Nervous System Disorder><Neural Cell><Neural Transmission><Neurocyte><Neurologic Disorders><Neurological Disorders><Neuronal Transmission><Neurons><Neurophysiology / Electrophysiology><O3><Ozone><Pathologic><Pharmaceutical Preparations><Primary Lateral Sclerosis><Primary Senile Degenerative Dementia><Process><Protein Biochemistry><Protein Engineering><Protein/Amino Acid Biochemistry><Proteins><Reactive Site><Receptor Activation><Receptor Protein><Regulation><Regulatory Protein><Reporting><Reproductive Cells><Research><Resolution><Rest><Role><SAP97><SAP97 protein><Seizure Disorder><Sex Cell><Signal Transduction><Signal Transduction Systems><Signaling><Single Crystal Diffraction><Site-Directed Mutagenesis><Site-Specific Mutagenesis><Size Exclusion Chromatography><Structural Models><Structure><Synapses><Synaptic><Synaptic Receptors><Synaptic Transmission><Targeted DNA Modification><Targeted Modification><Technology><Testing><Transmission><Work><X Ray Crystallographies><X-Ray Crystallography><X-Ray Diffraction Crystallography><X-Ray/Neutron Crystallography><Xray Crystallography><antagonism><antagonist><axon signaling><axon-glial signaling><axonal signaling><biological signal transduction><cognitive function><cognitive process><conformation><conformational><conformational state><conformationally><conformations><cryo-EM><cryoEM><cryogenic electron microscopy><desensitization><design><designing><drug/agent><electrophysiological><epilepsia><epileptogenic><genetic protein engineering><genetic regulatory protein><glia signaling><glial signaling><glutamate signaling><glutamatergic><glutamatergic dendrodendritic synapses><glutamatergic signaling><initial cell><member><membrane structure><nerve signaling><nervous system development><neural signaling><neurological disease><neuronal><neuronal signaling><neurotransmission><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel therapeutics><novel therapy><particle><patch clamp><positive allosteric modulator><postsynaptic><primary degenerative dementia><protein design><protein expression><receptor><receptor binding><receptor bound><receptor function><regulatory gene product><resolutions><response><senile dementia of the Alzheimer type><sexual cell><small molecule><social role><structural determinants><structural factors><success><synapse><synapse-associated protein 97><thermolability><thermostability><trafficking><transmission process>