Dr. Mary Munson
UMass Medical School
Host: Arne Gericke
Molecular Architecture and Function of the Exocyst Complex in Vesicle Trafficking
The regulation of vesicular traffic to precise intracellular compartments is essential for cell growth, homeostasis, signaling, cell division, and development. Membrane fusion between vesicles and their target membrane is carried out via SNARE proteins; however, additional regulatory control immediately prior to fusion is essential. The exocyst is a large, multisubunit protein complex implicated in tethering and regulation of the fusion of post-Golgi secretory vesicles with the plasma membrane, but its mechanism of action is poorly understood. We are using a multidisciplinary approach to elucidate its structure and function. Our most recent work demonstrates our groundbreaking purification method for intact yeast exocyst complexes, our genetic and biochemical dissection of the architecture of the exocyst, and the first view of the overall structure of the complex using negative stain EM. We are currently using a combination of cryoEM, crosslinking and mass spectrometry, mapping of subunits and binding partners using negative stain EM, as well as genetic, cell biological and single molecule biochemical analyses, to reveal exocyst structure and function at high resolution.