Neuronal nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels that mediate fast synaptic transmission and are important and novel therapeutic targets in neurodegenerative diseases and mental illness. Currently there is no atomic-resolution structure for any nicotinic receptor, and no receptor in this Cys-loop receptor superfamily has been structurally characterized in more than one conformation. The long-term objectives of the research are to better understand the conformational changes that underlie the transitions between different functional states and to develop reliable, atomic-resolution models of nAChRs relevant to structure-guided drug design. Toward these goals the following approach will be used. 1. Through receptor ortholog screening, identify an alpha7 receptor candidate for crystallization, and test conditions to optimize receptor stability in detergent. 2. Using fast-perfusion patch clamp and single channel analysis, test combinations of construct modifications and pharmacological probes to stabilize distinct receptor conformations. 3. Crystallize receptor in different conformational states and determine atomic-resolution structures of (a) a closed-resting receptor, (b) an open-activated receptor and (c) a closed-desensitized receptor. The structural studies will be complemented with functional assays that test new structure-based hypotheses regarding mechanisms of state transitions in the receptor. The results will have broad implications for the Cys-loop receptor family in general and alpha7 nAChRs specifically.

Public Health Relevance

The proposed studies will provide the first reliable structural templates for design of highly selective and innovative therapeutics useful in Alzheimer's and Parkinson's diseases and schizophrenia. Moreover, an understanding of how the structure of this important class of proteins changes upon activation will lend insight into biophysical process of great importance in addiction and other human nervous system health issues.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Career Transition Award (K99)
Project #
1K99NS077983-01
Application #
8276928
Study Section
NST-2 Subcommittee (NST)
Program Officer
Stewart, Randall R
Project Start
2012-04-01
Project End
2012-08-31
Budget Start
2012-04-01
Budget End
2012-08-31
Support Year
1
Fiscal Year
2012
Total Cost
$91,800
Indirect Cost
$6,800
Name
Oregon Health and Science University
Department
Neurosciences
Type
Schools of Medicine
DUNS #
096997515
City
Portland
State
OR
Country
United States
Zip Code
97239