1. Daniel Johansen Professor Tory Herman Mentor: Jen Jeffress UO Dept. of Biology and Institute of Molecular Biology Investigating the Role of Syd-1 in Synapse Development

2. Neuronal Communication Requires Proper Synapse Development

3. We are Studying Synapse Development Using Fruit Flies

4. Wild-type Synapses

5. The Protein Syd-1 is Required for Normal Synapse Development Syd-1 Mutant SynapsesWild-type Synapses Sigrist et. al 2010

6. Syd-1 has Sequence Similarity to GAPs Inactive Active Gap proteins “turn off” GTPases GTPase CYTOSKELETON

7. Does Syd-1 have GAP activity? Inactive Active GTPase CYTOSKELETON Over-express GTPase + Defect Worsens Over-express GEF Over-express GTPase Defect in flies Over-express GTPase + Defect Improves Over-express GAP

8. We Used Eye Development as a Read- out of GTPase Activity Wild-type Eye Rough Eye Death Rougher Eye

9. There are Six Different RhoGTPases that Syd-1 Might Regulate Multiple Rho-type GTPases in Drosophila Rac1 Rac2 Mtl Rho1 RhoL Cdc42

10. 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 and Syd-1

11. Syd-1 Appears to Not be Regulating Cdc42 Cdc42Cdc42 and Syd1

12. Syd-1 May be Acting Like a GAP for Rac1 and Rho1 Rho1 Rho1 and Syd1 Rac1 Rac1 and Syd1

13. Syd-1 Acts Upstream of Liprin- α Syd-1 Liprin-α Scaffolding Liprin-α Function Syd-1 Localizes Liprin-α to Synapses Wild-typeSyd-1 Mutant Sigrist et. al 2010

14. Liprin- α Regulates Axon Transport

15. Without Liprin-α, Axon Transport Does Not Occur Normally P value < 0.001

16. Does Syd-1 Help Liprin-α Promote Axon Transport? Syd-1 Liprin-α Scaffolding Axon Transport Liprin-α Functions Liprin-α Syd-1 ?

17. Our Preliminary Data Suggested Syd-1 May Also be Required for Axon Transport P value = 0.0255

18. Vesicle Tracking was Done to Determine Syd-1’s Role in Axon Transport

19. Results Showed Differences Compared to Wild-type Samples Percent Anterograde Movement of Syd-1 Percent Anterograde Movement of Wild-type

20. Bimodal Results Due to Location of Sampling Along the Axon Syd-1 Wild-type

21. Syd-1 Does Not Regulate Liprin-α in Axon Transport Syd-1 Liprin-α Scaffolding Axon Transport Liprin-α Functions Liprin-α

22. 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?

23. Acknowledgements Herman Lab Tory Herman Jennifer Jeffress Sasha Feoktistov Eric Lyons Jon Kniss Alex Whitebirch