Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Investigating the Role of Syd-1 in Synapse Development Daniel Johansen Professor Tory Herman Mentor: Jen Jeffress UO Dept. of Biology and Institute of Molecular Biology Neuronal Communication Requires Proper Synapse Development We are Studying Synapse Development Using Fruit Flies We are Studying Synapse Development Using Fruit Flies Wild-type Synapses The Protein Syd-1 is Required for Normal Synapse Development Wild-type Synapses Syd-1 Mutant Synapses Sigrist et. al 2010 Syd-1 has Sequence Similarity to GAPs GTPase Inactive GTPase Active CYTOSKELETON Gap proteins “turn off” GTPases Does Syd-1 have GAP activity? GTPase Inactive GTPase Active CYTOSKELETON Over-express GTPase Defect in flies Over-express GTPase + Over-express GEF Defect Worsens Over-express GTPase + Over-express GAP Defect Improves We Used Eye Development as a Readout of GTPase Activity Wild-type Eye Rough Eye Rougher Eye Death There are Six Different RhoGTPases that Syd-1 Might Regulate Multiple Rho-type GTPases in Drosophila Rac1 Rac2 Mtl Rho1 RhoL Cdc42 Genetic Crosses Were Done to Test the Interaction of Syd-1 with Some RhoGTPases Over-express Rac1 Over-express Rho1 + Syd-1 ??? Over-express Cdc42 OE GTPase OE GTPase and Syd-1 Syd-1 Appears to Not be Regulating Cdc42 Cdc42 Cdc42 and Syd1 Syd-1 May be Acting Like a GAP for Rac1 and Rho1 Rho1 Rac1 Rho1 and Syd1 Rac1 and Syd1 Syd-1 Acts Upstream of Liprin-α Liprin-α Function Syd-1 Liprin-α Scaffolding Syd-1 Localizes Liprin-α to Synapses Wild-type Syd-1 Mutant Sigrist et. al 2010 Liprin-α Regulates Axon Transport Without Liprin-α, Axon Transport Does Not Occur Normally P value < 0.001 Does Syd-1 Help Liprin-α Promote Axon Transport? Liprin-α Functions Syd-1 Syd-1 ? Liprin-α Scaffolding Liprin-α Axon Transport Our Preliminary Data Suggested Syd-1 May Also be Required for Axon Transport P value = 0.0255 Vesicle Tracking was Done to Determine Syd-1’s Role in Axon Transport Results Showed Differences Compared to Wild-type Samples Percent Anterograde Movement of Wild-type Percent Anterograde Movement of Syd-1 Bimodal Results Due to Location of Sampling Along the Axon Syd-1 Wild-type Syd-1 Does Not Regulate Liprin-α in Axon Transport Liprin-α Functions Syd-1 Liprin-α Scaffolding Liprin-α Axon Transport Future Study • Confirm the GAP activity of Syd-1 with the GTPases in vitro • Mutated Syd-1 that affects its GAP domain • Is the GAP domain necessary for synapse development? • Why is there a difference in movement speed between the location of sampling in the axon? Acknowledgements Herman Lab Tory Herman Jennifer Jeffress Sasha Feoktistov Eric Lyons Jon Kniss Alex Whitebirch