SNARE proteins form the minimal machinery required for regulated exocytosis, a process that underlies all information transfer within the nervous system. Lipid rafts, which have been implicated in a number of diseases including Alzheimer's and Parkinson's, are dynamic membrane microdomains that serve as platforms to regulate membrane function. While SNARE proteins have been found to localize to lipid rafts, and while disruption of lipid rafts results in the inhibition of regulated exocytosis, the exact role that lipid rafts exert in mediating exocytosis has not yet been determined. This proposal seeks to: 1) identify the specific stages of regulated exocytosis (e.g., core complex formation, priming, and fusion) in which lipid rafts play an important role; 2) determine the function of lipid rafts in modulating fusion pore dynamics; and 3) determine the regulatory elements involved in targeting of the neuronal SNARE protein Syntaxin 1A to lipid raft domains. The experimental approach will utilize a combination of carbon fiber amperometry and membrane capacitance measurements in both intact and cholesterol-depleted chromaffin cells, as well as biochemical lipid raft isolations in HEK cells heterologously expressing various wild-type and mutant SNARE proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
1F31NS053263-01
Application #
6998225
Study Section
Special Emphasis Panel (ZRG1-F03B (20))
Program Officer
Talley, Edmund M
Project Start
2005-09-01
Project End
2007-08-31
Budget Start
2005-09-01
Budget End
2006-08-31
Support Year
1
Fiscal Year
2005
Total Cost
$31,743
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Physiology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Lam, Alice D; Ismail, Sahar; Wu, Ray et al. (2010) Mapping dynamic protein interactions to insulin secretory granule behavior with TIRF-FRET. Biophys J 99:1311-20
Lam, Alice D; Tryoen-Toth, Petra; Tsai, Bill et al. (2008) SNARE-catalyzed fusion events are regulated by Syntaxin1A-lipid interactions. Mol Biol Cell 19:485-97
Gladycheva, Svetlana E; Lam, Alice D; Liu, Jiang et al. (2007) Receptor-mediated regulation of tomosyn-syntaxin 1A interactions in bovine adrenal chromaffin cells. J Biol Chem 282:22887-99