On Sep 8, 2017, Dr. Haijia Yu, Jiangsu Specially Appointed Professor at Nanjing normal University gave us a talk on the topic of "Functional Study of Sec1/Munc18 in intracellular Vesicle Fusion ".
The fusion of intracellular vesicles with the plasma membrane requires two classes of molecules – SNAP receptor (SNARE) and Sec1/Munc18 (SM) protein. In this presentation, Dr. Haijia Yu talked about his contribution to the understanding of the function and mechanisms of SM proteins, which are essential for every vesicle fusion pathway. He introduced macromolecular crowding agents into reconstituted fusion reactions to mimic the crowded cellular environment, and showed that SM proteins strongly promote the SNARE mediated membrane fusion, correlate well with physiology. Through the combined study of synaptic Munc18-1 and non-neuronal Munc18c, he demonstrated that one of the conserved functions of SM proteins is to recognize their individual cognate SNAREs and promote the trans-SNARE zippering. The MUNC18-1 gene is frequently mutated in Ohtahara Syndrome (OS), one of the severest forms of epilepsy. He discussed how OS-associated mutations impair the regulatory functions of Munc18-1 in synaptic vesicle fusion. After the interesting report, Dr. Haijia Yu answered questions raised by attending teachers and students.