On Monday, 25th of June 2018, Dr. Wenting Zhao, assistant professor at Nanyang Technological University, Singapore will visit us and will talk about
"Nanoscale manipulation of membrane curvature in live cells".
The lecture will take place at 5 pm in Building 605,
I. Med. Clinic, Seminar room 0.361.
Cellular membranes change conformation strikingly during many cellular processes, such as endocytosis, morphogenesis, migration and vesicle trafficking. Despite its crucial role in understanding many cellular behaviors, the molecular mechanism of how cells generate and control such membrane conformation remains unclear. A key features to characterize membrane conformation is membrane curvature. Extensive studies have been carried out to understand how various proteins participate in modulating the plasma membrane curvature. However, the reciprocal relationship of how the plasma membrane curvature affects the activities of proteins is much less explored, despite recent studies suggesting that the curved membrane itself can act as a signal for biochemical reactions and organizing membrane domains. This is largely due to technical challenges in controlling curvatures of the plasma membrane at nanoscale in live cells. In this talk, I will introduce our efforts in developing patterned nanostructures as a unique tool to generate pre-defined membrane curvatures in live cells, and how we use it to study the curvature influence on endocytosis and actin polymerization. A wide range of curvature from +100 nm to -500 nm radius can be generated on plasma membranes in live cells using our platform. We find that the positively curved membranes are preferred hotspots for clathrin- mediated endocytosis (CME) and that the key CME proteins, clathrin and dynamin, show a strong preference to positive membrane curvatures with a radius < 200 nm. Our results indicate that positive membrane curvatures can facilitate endocytosis by recruiting multiple endocytic proteins, which opens up a new angle to decipher endocytosis regulation. In addition to endocytosis, actin polymerization could also be guided by nanostructure guided membrane curvature generated. As a novel tool to manipulate membrane curvature in live cells, nanostructure platforms hold great potentials in studying diverse cellular behaviors beyond endocytosis and actin polymerization.