In vivo VPS-39 Expression
Since joining the Richmond lab in 2009, I have been examining molecular components that regulate synaptic vesicle release in Caenorhabditis elegans. Our lab has established that a highly conserved protein, tomosyn, is a potent inhibitor of vesicle release. However, little is known about how tomosyn itself is trafficked or regulated. I have identified a protein, VPS-39, which regulates the expression of a tomosyn reporter construct and has a functional role in synaptic vesicle release. VPS-39 has never been studied in our model system and so a critical experiment was to determine where this protein is endogenously expressed. To this end, I cloned the VPS-39 gene under its own promoter and fused it with a mCherry tag. By taking advantage of standard C. elegans techniques, I was able to visualize the expression pattern of VPS-39 in a living organism. The image was acquired on a laser-scanning confocal microscope (Olympus). VPS-39 appears to be expressed in many tissues, including but not limited to neurons and muscles, both of which are important for synaptic transmission. Now that I have established the expression pattern of this novel protein, we plan to fully characterize VPS-39 by conducting behavioral, pharmacological, electrophysiological, and ultra-structural analysis.