| Description |
During neurotransmission, neurons constantly fuse and recycle synaptic vesicles from the presynaptic membrane. Like other organelles, synaptic vesicles and proteins must be removed when damaged or overused. Build-up of damaged proteins may underlie neurodegenerative diseases like Parkinson's Disease. However, a pathway for removal of synaptic material is unknown. Common degradative pathways of neuronal cells include the autophagy, proteasome, and endo-lysosomal systems. Damage within any of these pathways leads to accumulation of waste at synapses. Members of the Jorgensen lab have recently discovered a new organelle in Caenorhabditis elegans called a surveillant. The lysosome-derived organelle is found to probe synaptic spaces and take up synaptic proteins and aggregates. Surveillant numbers doubled when stressed using a 34° C heat shock for 4 hours. Surveillants share important similarities to lysosomes; however, surveillants are transported to and from synapses, unlike lysosomes, which reside in the cell soma. To better understand the origins of surveillants, I aim to answer the question, what is the molecular composition of surveillants? To address this, we have tagged synaptic vesicle proteins as well as autophagy and lysosomal proteins with fluorescent proteins to measure if they colocalize with surveillants. Identifying whether colocalization occurs is important in uncovering what pathway surveillants are involved in and how they can be differentiated from other degradative organelles. This research is important for broadening our understanding of how neurons respond to severe stress, with relevance to human diseases such as stroke, Alzheimer's, and Parkinson's Disease. |
