Wednesday 26 April 2017
Title: “Quantitative analysis of dynamic macromolecular complexes”
Speaker:
Dr. Minjoung Kyoung, UMBC
Abstract:
Neuronal communication occurs by the release of neurotransmitters, which depends on the fusion of neurotransmitter-containing vesicles (i.e. synaptic vesicles) with the plasma membrane at the active zone in axonal terminals. The fusion of synaptic vesicles is triggered by an influx of Ca2+ ions into the neuron in a highly controlled manner via multiple protein-protein interactions through a macromolecular complex formed by three SNARE proteins, synaptotagmin-I and complexin. A number of in vitro assays have been developed to study this process. However, most of them were limited to measuring only the lipid mixing that can occur at the ‘hemifusion’ status without release of neurotransmitter content. We have developed a robust novel single-vesicle fusion assay that simultaneously monitor both the lipid mixing and the content release, further allowing us to dissect individual steps of the fusion process. In this work, we will discuss a mechanism of neuronal communication, which involves a macromolecular complex of neuronal SNARE and its accessory proteins
Our lab is also interested in studying dynamics of other transient macromolecular complexes involved in signaling and metabolic pathways. Investigating dynamics of macromolecular complexes within cells and tissues are critical to the understanding of the development and treatment of various diseases including cancer. However, current methods to dissect transient protein-protein interactions as a basis of macromolecular complex formation and regulation are limited. We have developed a lattice light sheet correlation microscope to tackle the dynamics of macromolecular complexes in signaling and metabolic pathways in live cells. As a complementary in vitro technology, we have developed nano-reaction chambers to dissect transient macromolecular interactions at single molecule level. In this work, we will discuss newly developed technologies and their applications.
Host: Dr. Yantao Li