Study of endosomal membrane-interaction with acoustic biosensors
Funding: Human Frontier Science Program (HFSP) 2020-2024
Self-organization and the biomechanical properties of the endosomal membrane is an international collaborative project coordinated by Biosensors lab where, in addition to FORTH, three more international partners participate from Germany (Max Planck Inst.), Japan (Kanazawa Univ.), and the USA (Stanford). Funded by the HFSP, the project uses advanced biophysical techniques, biochemical methods, and simulations to elucidate the mechanism of endosomal membrane-tethering mediated by EEA1, a 200 nm long coiled-coil membrane binding protein.
Figure 1: an example of a QCMD experiment showing the formation of a model lipid membrane followed by binding of EEA1 to the membrane.
The role of our group in the project is to examine the collective behavior or EEA1 on phospholipid membranes so that it can be compared to single molecule studies (Max Plank and Kanazawa Univ.) and simulation results (Stanford). To this end, we are using the Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) to investigate in real time interactions between the coiled-coil protein EEA1 with various lipids and its partner proteins, i.e., small GTPase Rab5s that regulate EEA1 function in vivo. Our results provide real-time monitoring of the EEA1 membrane protein binding to the lipid membrane (Figure 1) from which we can derive information on the structure conformation of the protein and binding affinity to the membrane and/or Rad5.