The long-term goal of this project is to elucidate structural and functional features of nicotinic acetylcholine receptors containing a7, or8 or or9 subunits (a7-, a8-, or a9-nAChR). a7, a8 and a9 are the most ancient nAChR subunits, and the homomeric complexes that they are postulated to create are perhaps the most simple form of nAChR. Nevertheless, these nAChR, particularly a7-nAChR, are widespread mediators of classical excitatory neurotransmission. They also may play novel physiological roles as modulators of neurotransmitter release, neurite outgrowth, and even neuronal death/survival. a7-nAChR also have been implicated in development, differentiation, and disease of the nervous system and are targets of tobacco nicotine action. The project is founded in preliminary work demonstrating expression of these subunits as homomeric nAChR in the native nAChR-null human epithelial cell line SH-EP1 and revealing startling properties of wild-type and mutant forms of these nAChR.
The specific aims of the project are (1) to generate and characterize mutant forms of a7-nAChR that recognize nicotine as a functional antagonist, (2) to generate and characterize functional forms of truncated a7nAChR, (3) to ascertain whether nAChR containing oc7 subunits can also assemble as heteromers and whether such heteromeric a7-nAChR have distinctive properties, and (4) to characterize heterologously expressed forms of a8nAChR and a9-nACh R. These studies will test hypotheses that selected mutation(s) of ligand binding and/or channel lining domains of nAChR influence whether drugs act as agonists or antagonists. They will test the hypothesis that truncated forms of nAChR subunits can be engineered to nevertheless retain abilities to assemble as ligand-binding, functional ion channels. The project will also test the hypothesis that a7 subunits only assemble as homomers. It will elucidate nAChR function when expressed in the same cellular environment and whether/how ceil environment influences expression of nAChR. The planned studies will help to reveal structural features critical to ligand recognition, assembly, and function of nACh R. Findings in the project are relevant to our understanding of the important roles played by nAChR in nervous system function and disease and in nicotine dependence.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS040417-02
Application #
6394501
Study Section
Special Emphasis Panel (ZRG1-BDCN-2 (01))
Program Officer
Stewart, Randall
Project Start
2000-07-01
Project End
2003-06-30
Budget Start
2001-07-01
Budget End
2002-06-30
Support Year
2
Fiscal Year
2001
Total Cost
$397,174
Indirect Cost
Name
St. Joseph's Hospital and Medical Center
Department
Type
DUNS #
131606022
City
Phoenix
State
AZ
Country
United States
Zip Code
85013
Mulcahy, Matthew J; Blattman, Sydney B; Barrantes, Francisco J et al. (2015) Resistance to Inhibitors of Cholinesterase 3 (Ric-3) Expression Promotes Selective Protein Associations with the Human ?7-Nicotinic Acetylcholine Receptor Interactome. PLoS One 10:e0134409
Wu, Jie; Gao, Ming; Shen, Jian-Xin et al. (2013) Cortical control of VTA function and influence on nicotine reward. Biochem Pharmacol 86:1173-80
Zhang, Die; Gao, Ming; Xu, Dan et al. (2012) Impact of prefrontal cortex in nicotine-induced excitation of ventral tegmental area dopamine neurons in anesthetized rats. J Neurosci 32:12366-75
Yang, Kechun; Buhlman, Lori; Khan, Ghous M et al. (2011) Functional nicotinic acetylcholine receptors containing ?6 subunits are on GABAergic neuronal boutons adherent to ventral tegmental area dopamine neurons. J Neurosci 31:2537-48
Wu, Jie; Lukas, Ronald J (2011) Naturally-expressed nicotinic acetylcholine receptor subtypes. Biochem Pharmacol 82:800-7
Gao, Ming; Jin, Yu; Yang, Kechun et al. (2010) Mechanisms involved in systemic nicotine-induced glutamatergic synaptic plasticity on dopamine neurons in the ventral tegmental area. J Neurosci 30:13814-25
Zheng, Chao; Wang, Meng-Ya; Liu, Qiang et al. (2009) U18666A, a cholesterol-inhibition agent, modulates human neuronal nicotinic acetylcholine receptors heterologously expressed in SH-EP1 cell line. J Neurochem 108:1526-38
Yang, Kechun; Hu, Jun; Lucero, Linda et al. (2009) Distinctive nicotinic acetylcholine receptor functional phenotypes of rat ventral tegmental area dopaminergic neurons. J Physiol 587:345-61
Yu, Kewei D; Liu, Qiang; Wu, Jie et al. (2009) Kinetics of desensitization and recovery from desensitization for human alpha4beta2-nicotinic acetylcholine receptors stably expressed in SH-EP1 cells. Acta Pharmacol Sin 30:805-17
Liu, Qiang; Yu, Ke-wei; Chang, Yong-chang et al. (2008) Agonist-induced hump current production in heterologously-expressed human alpha4beta2-nicotinic acetylcholine receptors. Acta Pharmacol Sin 29:305-19

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