Our long-term goal is to understand how the molecular constituents of synapses are organized during development, and to determine the mechanisms that regulate them during plasticity. During more than a decade, our studies have centered on the role of Discs-Large, a scaffolding protein of the PSD95 family. These studies have been instrumental to understanding the dynamics of synapse growth, how scaffolding proteins are regulated, and what additional proteins are required for synaptic protein assembly. More recently, our studies have centered on the regulation of the synaptic cytoskeleton during synapse growth. We have found that a conserved cassette, consisting of the scaffolding proteins Bazooka/Par-3, Par6, and aPKC, plays a primary role in cytoskeletal rearrangements required for new synapse formation. In epithelial cells this complex is necessary to establish cell polarity, and alterations in these proteins result in loss of cell polarity and cancer. In the present proposal we will center on the molecular mechanism by which microtubule dynamics are regulated during synapse growth.
In aim 1 we use a genetic analysis in fixed and living preparations to test the hypothesis that aPKC regulates pre- and postsynaptic microtubule dynamics, and that this is required for new synapse formation.
In Aim 2 we will investigate the role of Putsch, a microtubule associated protein regulated by aPKC. Finally, in aim 3 we will investigate the role of Baz in synaptic development. We expect that the proposed studies will substantially contribute to an understanding of the role of the cytoskeleton during new synapse formation. Because many of these proteins are highly conserved across diverse phylogenies, our studies in Drosophila will also be relevant to vertebrates and mammals, as we have demonstrated in our previous work. An understanding of the factors involved in building a functional synapse will be essential to decipher the mechanisms underlying a number of neural disorders, as well as to design strategies to repair damage after stroke, trauma, or disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS030072-16
Application #
7175345
Study Section
Special Emphasis Panel (ZRG1-MDCN-A (06))
Program Officer
Porter, John D
Project Start
1992-01-01
Project End
2010-01-31
Budget Start
2007-02-01
Budget End
2008-01-31
Support Year
16
Fiscal Year
2007
Total Cost
$356,308
Indirect Cost
Name
University of Massachusetts Medical School Worcester
Department
Biology
Type
Schools of Medicine
DUNS #
603847393
City
Worcester
State
MA
Country
United States
Zip Code
01655
Ramachandran, Preethi; Barria, Romina; Ashley, James et al. (2009) A critical step for postsynaptic F-actin organization: regulation of Baz/Par-3 localization by aPKC and PTEN. Dev Neurobiol 69:583-602
Chai, Andrea; Withers, James; Koh, Young Ho et al. (2008) hVAPB, the causative gene of a heterogeneous group of motor neuron diseases in humans, is functionally interchangeable with its Drosophila homologue DVAP-33A at the neuromuscular junction. Hum Mol Genet 17:266-80
Griffith, Leslie C; Budnik, Vivian (2006) Plasticity and second messengers during synapse development. Int Rev Neurobiol 75:237-65
Ruiz-Canada, Catalina; Budnik, Vivian (2006) Introduction on the use of the Drosophila embryonic/larval neuromuscular junction as a model system to study synapse development and function, and a brief summary of pathfinding and target recognition. Int Rev Neurobiol 75:1-31
Ruiz-Canada, Catalina; Budnik, Vivian (2006) Synaptic cytoskeleton at the neuromuscular junction. Int Rev Neurobiol 75:217-36
Mathew, Dennis; Popescu, Andrei; Budnik, Vivian (2003) Drosophila amphiphysin functions during synaptic Fasciclin II membrane cycling. J Neurosci 23:10710-6
Packard, Mary; Mathew, Dennis; Budnik, Vivian (2003) FASt remodeling of synapses in Drosophila. Curr Opin Neurobiol 13:527-34
Koh, Young-Ho; Ruiz-Canada, Catalina; Gorczyca, Michael et al. (2002) The Ras1-mitogen-activated protein kinase signal transduction pathway regulates synaptic plasticity through fasciclin II-mediated cell adhesion. J Neurosci 22:2496-504
Park, Demian; Coleman, Melissa J; Hodge, James J L et al. (2002) Regulation of neuronal excitability in Drosophila by constitutively active CaMKII. J Neurobiol 52:24-42
Thomas, U; Ebitsch, S; Gorczyca, M et al. (2000) Synaptic targeting and localization of discs-large is a stepwise process controlled by different domains of the protein. Curr Biol 10:1108-17

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