Grant: Discovery Grants Program - Individual
University of Western Ontario
$35,000.00
The role of phosphorylation on the control of neurosteroid activity on GABA-A receptors
EF 2014-15
Résumé
The regulation of ion channel function is accomplished by a number of differing mechanisms ranging from transcriptional control of expression to covalent modifications of the ion channel protein. The function of GABA-A receptors is controlled by differential expression of a large family of proteins and by the phosphorylation of a number of sites on its constituent subunits. As well GABA-A receptor expression is controlled by naturally occurring steroid molecule metabolites, referred to as neurosteroids. Neurosteroids bind to GABA-A receptors enhancing or reducing the efficacy of GABA activity. Evidence suggests that covalent modifications of GABA-A receptors may also control the activity of neurosteroids. However, it is unclear how this occurs. In particular the phosphorylation sites on GABA receptors are targeted by a number of differing kinases and each may have a differing effect on the function of neurosteroids. The hypothesis that will be explored by this application is that differing phosphorylation sites on GABA-A receptors will either enhance or reduce the activity of GABA-A receptors by altering the activation and desensitiation kinetics of the receptor. This hypothesis will be tested by employing recombinant GABA-A receptors that are either fast or slow desensitizing ""synaptic"" subunit combinations. Site directed mutagenesis will be used to alter the phosphorylation sites to either block phosphorylation or produce phosphomimetic mutants. Altered channel kinetics will be examined by both short (< 2ms) and long (500 ms) application of GABA to mimic synaptic activity and determine desenitization kientics respectively. This project will provide a high level training to graduate students in cellular electrophysiology, biophysics and molecular biology. Overall, the goal of this research is to understand how covalent modifications of GABA-A receptors alter neurosteroid activity and how these changes may ultimately have an impact on the control of neural network activity.
Programme
Discovery Grants Program - Individual
Bénéficiaire
Emplacement
Ontario, Canada
Type de bénéficiaire
Academia
Type
Grant
Source
NSERC's Awards Data
Tel que publié
Application id
RGPIN-2014-05571
Name nom
Poulter, Michael
Department département
Robarts Research Institute
Organization id
36
Institution établissement
University of Western Ontario
Province en
Ontario
Province fr
Ontario
Country en
CANADA
Country fr
CANADA
Fiscal year exercice financier
2014
Competition year année de concours
2014
Award amount
35000
Program id
RGPIN
Program name en
Discovery Grants Program - Individual
Program name fr
Programme de subventions à la découverte - individuelles
Group en
Discovery grants programs
Group fr
Programmes de subventions à la découverte
Committee code
1501
Committee name en
Genes, Cells and Molecules
Committee name fr
Gènes, cellules et molécules
Area of application code
1101
Area of application group en
Health, education and social services
Area of application group fr
Santé publique, éducation et services sociaux
Area of application en
Human health (including medically-related psychological research)
Area of application fr
Santé publique (y compris recherche psychologique liée à la médecine)
Research subject code
5501
Research subject group en
Animal biology
Research subject group fr
Biologie animale
Research subject en
Neurophysiology
Research subject fr
Neurophysiologie
Partie
1
Nb partie
1
Application title
The role of phosphorylation on the control of neurosteroid activity on GABA-A receptors
Keyword
NSERC
Application summary
The regulation of ion channel function is accomplished by a number of differing mechanisms ranging from transcriptional control of expression to covalent modifications of the ion channel protein. The function of GABA-A receptors is controlled by differential expression of a large family of proteins and by the phosphorylation of a number of sites on its constituent subunits. As well GABA-A receptor expression is controlled by naturally occurring steroid molecule metabolites, referred to as neurosteroids. Neurosteroids bind to GABA-A receptors enhancing or reducing the efficacy of GABA activity. Evidence suggests that covalent modifications of GABA-A receptors may also control the activity of neurosteroids. However, it is unclear how this occurs. In particular the phosphorylation sites on GABA receptors are targeted by a number of differing kinases and each may have a differing effect on the function of neurosteroids. The hypothesis that will be explored by this application is that differing phosphorylation sites on GABA-A receptors will either enhance or reduce the activity of GABA-A receptors by altering the activation and desensitiation kinetics of the receptor. This hypothesis will be tested by employing recombinant GABA-A receptors that are either fast or slow desensitizing ""synaptic"" subunit combinations. Site directed mutagenesis will be used to alter the phosphorylation sites to either block phosphorylation or produce phosphomimetic mutants. Altered channel kinetics will be examined by both short (< 2ms) and long (500 ms) application of GABA to mimic synaptic activity and determine desenitization kientics respectively. This project will provide a high level training to graduate students in cellular electrophysiology, biophysics and molecular biology. Overall, the goal of this research is to understand how covalent modifications of GABA-A receptors alter neurosteroid activity and how these changes may ultimately have an impact on the control of neural network activity.
