The long-term goal of this research is to elucidate molecular mechanisms involved in synaptic vesicles reformation after exocytosis. This is a function essential for sustained synaptic transmission. Understanding mechanisms underlying presynaptic function is important from many perspectives. Various motor and behavioral deficits may result from defects in molecules required for presynaptic functions; excess neurotransmitter release during epileptic seizures may result in excitotoxicity and consequent cell death in the brain; altered activity-dependent regulation of transmitter release may underlie deficits in learning and memory. This proposal exploits the convenience of Drosophila as an experimental organism for incisive experiments on the mechanisms of presynaptic function. Such studies in Drosophila are validated by numerous examples of conservation of neural mechanisms across phylogeny. The rate of progress of the proposed analyses in Drosophila is facilitated not only by its short generation time and facility for genetics, but also by novel resources provided by the Drosophila genome projects, and newly developed technologies for gene disruption, perturbation and replacement in vivo. The proposal seeks to use an integrated, multidisciplinary approach to analyzing mechanisms of synaptic vesicle recycling. Using the facility of Drosophila for transgene manipulation, the first specific aim this grant seeks to understand how novel presynaptic proteins, stonedA and stonedB, accomplish their essential roles in recycling synaptic vesicles. The second and third aims seek to identify novel proteins that function at the nerve terminal for recycling synaptic vesicles, by molecular, genetic, and cell biological analysis of two genetic mutants in Drosophila whose preliminary characterization indicates altered endocytosis at nerve terminals. The last aim of the grant addresses a fundamental question in the cell biology of neurotransmitter release: are there different pathways for transmitter release and synaptic-vesicle reformation? Combining transgene manipulation, genetic screens and molecular genetics, with novel and established cell biological assays for presynaptic functions in Drosophila, the proposed experiments, if successful, should contribute significantly to current knowledge of presynaptic functions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS034889-08
Application #
6722890
Study Section
Special Emphasis Panel (ZRG1-MDCN-1 (01))
Program Officer
Murphy, Diane
Project Start
1997-03-01
Project End
2005-03-31
Budget Start
2004-04-01
Budget End
2005-03-31
Support Year
8
Fiscal Year
2004
Total Cost
$303,000
Indirect Cost
Name
University of Arizona
Department
Microbiology/Immun/Virology
Type
Schools of Arts and Sciences
DUNS #
806345617
City
Tucson
State
AZ
Country
United States
Zip Code
85721
Sanyal, Subhabrata; Jennings, Tricia; Dowse, Harold et al. (2006) Conditional mutations in SERCA, the Sarco-endoplasmic reticulum Ca2+-ATPase, alter heart rate and rhythmicity in Drosophila. J Comp Physiol B 176:253-63
Narayanan, Radhakrishnan; Leonard, Marilyn; Song, Byeong Doo et al. (2005) An internal GAP domain negatively regulates presynaptic dynamin in vivo: a two-step model for dynamin function. J Cell Biol 169:117-26
Sanyal, S; Consoulas, C; Kuromi, H et al. (2005) Analysis of conditional paralytic mutants in Drosophila sarco-endoplasmic reticulum calcium ATPase reveals novel mechanisms for regulating membrane excitability. Genetics 169:737-50
Rikhy, Richa; Ramaswami, Mani; Krishnan, K S (2003) A temperature-sensitive allele of Drosophila sesB reveals acute functions for the mitochondrial adenine nucleotide translocase in synaptic transmission and dynamin regulation. Genetics 165:1243-53
Estes, Patricia S; Jackson, Taryn C; Stimson, Daniel T et al. (2003) Functional dissection of a eukaryotic dicistronic gene: transgenic stonedB, but not stonedA, restores normal synaptic properties to Drosophila stoned mutants. Genetics 165:185-96
Narayanan, Radhakrishnan; Ramaswami, Mani (2003) Regulation of dynamin by nucleoside diphosphate kinase. J Bioenerg Biomembr 35:49-55
Chen, Mai-Lei; Green, David; Liu, Lei et al. (2002) Unique biochemical and behavioral alterations in Drosophila shibire(ts1) mutants imply a conformational state affecting dynamin subcellular distribution and synaptic vesicle cycling. J Neurobiol 53:319-29
Krishnan, K S; Rikhy, R; Rao, S et al. (2001) Nucleoside diphosphate kinase, a source of GTP, is required for dynamin-dependent synaptic vesicle recycling. Neuron 30:197-210
Stimson, D T; Estes, P S; Rao, S et al. (2001) Drosophila stoned proteins regulate the rate and fidelity of synaptic vesicle internalization. J Neurosci 21:3034-44
Sanyal, S; Tolar, L A; Pallanck, L et al. (2001) Genetic interaction between shibire and comatose mutations in Drosophila suggest a role for snap-receptor complex assembly and disassembly for maintenance of synaptic vesicle cycling. Neurosci Lett 311:21-4

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