Project Summary
While a growing body of work has contributed to our understanding of synapse
assembly, less is known about how synapses are maintained throughout life. This long life of
synapses is crucial for the sustained function of neural circuits, including those supporting
cognition, movement, and other vital functions. However, maintaining long-lived synaptic
connections presents a cell biological challenge, as synaptic proteins have finite lifetimes,
synaptic vesicles turnover rapidly, and protein synthesis is scarce in the presynaptic
compartment. This project will study the mechanisms of presynaptic maintenance, using C.
elegans as a model system. In Aim 1, I will investigate the proteins involved in maintaining
synaptic structures, using the auxin-inducible degron system to remove the candidate proteins
SYD-2, SYD-1, SAD-1, CDK-5, and PCT-1 from the mature nervous system. Changes in
synapse organization will be assessed using endogenous, cell-type specific markers of synaptic
vesicles and active zone proteins. In Aim 2, I will identify regulators of the presynaptic
scaffolding protein SYD-2. I will implement a visual forward genetic screen to identify candidates
that regulate SYD-2 stability, using a pulse-chase SYD-2 HaloTag approach to visualize SYD-2
turnover. In Aim 3, I will identify regulators of SYD-2 through the use of Split-TurboID proximity
biotinylation to detect interacting partners of SYD-2 in the presynaptic compartment. Candidate
regulators of SYD-2 turnover will be assessed using the SYD-2 HaloTag system. This work will
identify key synaptic maintenance proteins and their regulators. Understanding the mechanisms
that maintain stable synapses provides therapeutic avenues for preserving synapses in aging
and neurodegenerative diseases. This project, performed in the laboratory of Dr. Kang Shen at
Stanford University, provides a strong training opportunity for me in the fields of cell biology and
neuroscience, and I will gain new experience with the C. elegans model system, genetic
manipulations, and microscopy.