Tuesday, July 1, 2025 7/1/2025

Neurosteroid and Cholesterol Binding to Integral Membrane Proteins

Award Number: R35GM149287
ORGANIZATION: NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES
OPDIV: NIH
AWARD CLASS: DISCRETIONARY
AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)
PERIOD OF PERFORMANCE START DATE: 06/01/2023
PERIOD OF PERFORMANCE END DATE: 05/31/2028

Group Awards By:

View Award Description

Neurosteroid and Cholesterol Binding to Integral Membrane Proteins - Project Summary The Evers laboratory studies the binding interactions of neurosteroids and cholesterol with integral membrane proteins, with the aim of identifying the specific binding events underlying sterol modulation of protein function. Our major focus is on neurosteroid (NS) modulation of -aminobutyric acid type A receptors (GABAA- R). Neurosteroids are important modulators of neuronal excitability and nervous system development with enormous therapeutic potential as anesthetics, anti-depressants and neuro-protectants. We have shown that there are multiple, subunit-specific binding sites for neurosteroids on GABAA receptors, each of which contributes to the functional effects of neurosteroids. In the proposed research, we will use photolabeling techniques to define the precise sites at which the major classes of neurosteroids bind on the most abundant forms of synaptic and extra-synaptic GABAA receptors and determine the functional significance of each identified binding site by assessing the effect of targeted amino acid substitutions on NS modulation of GABAA- R currents. To identify photo-labeled residues we will utilize state-of-the-art protein chemistry and expression techniques in conjunction with cutting edge mass spectrometry (MS) methods, including middle-down and intact protein MS. High-resolution cryogenic-electron microscopy structures will be obtained to identify the atomic details of novel NS binding sites and to investigate binding interactions that appear to stabilize conformations not captured in current structures. Fluorescence-based binding assays will then be used to measure the site-specific affinity of various NS for the identified binding sites. These assays will be adapted to stopped-flow fluorimetry to determine the state-dependence of binding and to a plate reader format to screen for site-specific agonists and antagonists. The long term goal of our NS program is to develop and use site-specific NS ligands to probe the role of specific NS binding sites and GABAA-R subtypes in the behavioral effects of endogenous NS and the mechanisms of action of NS sedatives and anesthetics. We have also used cholesterol-analogue photolabeling to identify specific binding sites that mediate cholesterol inhibition of the lipid scramblase, nhTMEM16, and cholesterol modulation of mTOR1 by the lysosomal membrane protein GPR155. Both nhTMEM16 and GPR155 have two specific cholesterol binding sites per protein monomer and we are using targeted amino acid substitution to understand the functional role of each site. We are also developing fluorescence-based binding assays to measure cholesterol affinity and sterol specificity for these sites. Novel cholesterol binding sites present new targets for small molecule allosteric modulators of membrane protein function and the tools we have developed are widely applicable to identifying binding sites on other cholesterol-modulated proteins and screening for site-specific ligands.


Issue Date FY	Funding FY	Legal Entity Name	Legal Entity Address	Legal Entity City	Legal Entity State	Legal Entity Zip Code	Legal Entity COUNTY	Legal Entity COUNTRY	Assistance Listing	Award Code	Budget Year	Action Date	Action Type	Action Amount

Issue Date FY: 2025 ( Subtotal = $552,219 )
2025	2025	WASHINGTON UNIVERSITY, THE	1 BROOKINGS DR	SAINT LOUIS	MO	63130	SAINT LOUIS	USA	Biomedical Research and Research Training	001	3	5/30/2025	NON-COMPETING CONTINUATION	$552,219
2025	2024	WASHINGTON UNIVERSITY, THE	1 BROOKINGS DR	SAINT LOUIS	MO	63130	SAINT LOUIS	USA	Biomedical Research and Research Training	000	2	11/5/2024	NON-COMPETING CONTINUATION	$0
														Subtotal = $552,219

Issue Date FY: 2024 ( Subtotal = $752,219 )
2024	2024	WASHINGTON UNIVERSITY, THE	ONE BROOKINGS DR	SAINT LOUIS	MO	63110	SAINT LOUIS CITY	USA	Biomedical Research and Research Training	001	2	6/6/2024	SUPPLEMENT FOR EXPANSION	$200,000
2024	2024	WASHINGTON UNIVERSITY, THE	ONE BROOKINGS DR	SAINT LOUIS	MO	63110	SAINT LOUIS CITY	USA	Biomedical Research and Research Training	000	2	5/15/2024	NON-COMPETING CONTINUATION	$552,219
														Subtotal = $752,219

Issue Date FY: 2023 ( Subtotal = $552,812 )
2023	2023	WASHINGTON UNIVERSITY, THE	ONE BROOKINGS DR	SAINT LOUIS	MO	63130	SAINT LOUIS	USA	Biomedical Research and Research Training	000	1	5/11/2023	NEW	$552,812
														Subtotal = $552,812

Grand Total All Awards = $1,857,250

Top

All Categories

About

Search

Reports

Data Submission

Award Information

Neurosteroid and Cholesterol Binding to Integral Membrane Proteins

Award Number: R35GM149287

ORGANIZATION: NATIONAL INSTITUTE OF GENERAL MEDICAL SCIENCES

OPDIV: NIH

AWARD CLASS: DISCRETIONARY

AWARD ACTIVITY TYPE: SCIENTIFIC/HEALTH RESEARCH (INCLUDES SURVEYS)

PERIOD OF PERFORMANCE START DATE: 06/01/2023

PERIOD OF PERFORMANCE END DATE: 05/31/2028

Federal Websites

Department of Health & Human Services

HHS Operating Divisions

HHS Staff Divisions

Download A Document Viewer