The goal of this project is to use new advances in cryo-electron microscopy (cryo-EM) technology to elucidate the structures of, at high-resolution, a range of functional states of ionotropic glutamate receptor (iGluR) ion channels, and to use complementary functional and biochemical assays to validate our findings and hypotheses driven by our solved cryo-EM models. iGluRs are responsible for the majority of excitatory neurotransmission, and are implicated in a wide range of pathologies, from neurodegenerative diseases and psychiatric disorders, to epilepsy and stroke-induced trauma. Current design of therapeutics targeting the range of iGluR functional states that dictate these different disease states is hindered by a lack of information describing iGluRs outside of a closed-channel state. This research will directly address the need for new views into these functional states by using cryo-EM based methods, which will allow crystallographic barriers in analyzing iGluR states to be overcome. Using state-of-the-art cryo-EM techniques, high-resolution cryo-EM of iGluRs will be established. With fluorescence-based construct screening strategies, new targets for isolating separate structural states in iGluR function will be identified. Namely, how auxiliary proteins interact with/regulate iGluRs and iGluR gating will be targeted. After cryo-EM analysis, data will be probed using advanced electrophysiological techniques and biochemical interrogation. The methods used in this project will serve as a foundation for investigating functional states across ion channel families, and may provide a much-needed template for structure-based drug design of new molecules targeting iGluR states.

Public Health Relevance

The proposed research targets the elucidation of three-dimensional structures of various functional states in a group of ion channels called ionotropic glutamate receptors (iGluRs). These structures will provide highly detailed information to help better understand how iGluRs function across various disease-related states, such as in neurodegenerative diseases and psychiatric disorders. The outcomes of this project will provide a foundation, from a structural biology perspective, for novel design of therapeutics targeting an array of iGluR functional states across neurological disorders.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31NS093838-01A1
Application #
9121639
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Silberberg, Shai D
Project Start
2016-09-01
Project End
2019-08-31
Budget Start
2016-09-01
Budget End
2017-08-31
Support Year
1
Fiscal Year
2016
Total Cost
Indirect Cost
Name
Columbia University (N.Y.)
Department
Biochemistry
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
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Singh, Appu K; McGoldrick, Luke L; Twomey, Edward C et al. (2018) Mechanism of calmodulin inactivation of the calcium-selective TRP channel TRPV6. Sci Adv 4:eaau6088
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