Please join the Department of Pharmacology, Addiction Science, and Toxicology for our (PHAST) Spring 2026 Seminar

Please, join the Department of Pharmacology, Addiction Science, and Toxicology for a seminar with

Speaker: Dr. Hongkyun Kim, Chicago Medical School, Rosalind Franklin University, Cell Biology & Anatomy Department

Seminar Title: Orchestrating Elegant Movement: Insights from C. elegans synapses

Wednesday, May 6, 2026, 12:00pm - 1:00pm

Hosted by Dr. Changhoon Jee

Brief Summary of presentation: We use C. elegans as a model organism to investigate how the presynaptic active zone is organized and dynamically remodeled in response to changes in activity. Our work focuses on the regulation of CaV2 voltage-gated calcium channels, the primary source of calcium influx that triggers neurotransmitter release. The abundance of CaV2 channels at synapses is a key determinant of synaptic strength and plasticity, yet the molecular mechanisms underlying their trafficking and degradation remain poorly understood. Leveraging the genetic tractability of C. elegans, we identify and characterize proteins that mediate CaV2/UNC-2 channel degradation. Unexpectedly, we discovered that synaptic vesicle fusion efficiency itself regulates CaV2 channel abundance. When fusion frequency is high, CaV2 levels at synapses decrease, reducing calcium influx and dampening subsequent vesicle release. Conversely, low fusion frequency leads to increased CaV2 accumulation. This feedback mechanism represents a cell-autonomous form of presynaptic homeostatic regulation, distinct from the well-characterized trans-synaptic homeostatic pathways. Given the intimate relationship between vesicle fusion and CaV2 regulation, we further examined how specific endocytic pathways influence CaV2 channels and the synaptic vesicle fusion machinery, and how disruption of one endocytic pathway affects others. Together, our findings reveal a bidirectional interplay between synaptic vesicle cycling and calcium channel regulation that fine-tunes presynaptic function.

Zoom details
https://tennesseehipaa.zoom.us/j/82299954759?pwd=THQO75ih3b3A1Db78FUHXpMauhyRzr.1

Meeting ID: 822 9995 4759
Passcode: 099874