IPLS/BioP Seminar: Prof. Padmini Rangamani (University of California)
13 April 2021, 5:00 pm–6:00 pm
Title: Transport phenomena in lipid bilayers: feedback between curvature, protein diffusion, and aggregation
Abstract: Cellular membranes are elastic lipid bilayers that contain a variety of proteins, including ion channels, receptors and scaffolding proteins. These proteins are known to diffuse and aggregate in the plane of the membrane and to influence the bending of the membrane. Experiments have shown that lipid flow in the plane of the membrane is closely coupled with the diffusion and aggregation of proteins. Thus, there is a need for a comprehensive framework that accounts for the interplay between these processes. In this work, I will present a theory for the coupled in-plane viscous flow of lipids, diffusion of transmembrane proteins, aggregation of proteins, and elastic deformation of lipid bilayers. The proteins in the membrane are modeled such that they influence membrane bending by inducing a spontaneous curvature. We formulate the free energy of the membrane with a Helfrich-like curvature elastic energy density function modified to account for the chemical potential energy of proteins. We derive the conservation laws and equations of motion for this system. Finally, we present results from dimensional analysis and numerical simulations and demonstrate the effect of coupled transport processes in governing the dynamics of membrane bending, protein aggregation, and diffusion. We find that feedback between curvature and aggregation results in domains that result in membrane micro domains. This work is in collaboration with David Saintillan (UCSD, MAE).
Host: Andela Saric (email@example.com)
Please join the meeting on Zoom here: https://ucl.zoom.us/j/96499688472?pwd=bGZ6SkRXSzh3OFFOSXZKbHo0MFRnQT09
Meeting ID: 964 9968 8472 Passcode: 916288
For best functionality please ensure when you join the call you turn off your webcam and mute your microphone, to save bandwidth. If you have a question, please use the meeting Chat panel to let the host know, then switch on your camera and microphone on to ask the question when prompted.
About the Speaker
Prof. Padmini Rangamani
at University of California, San Diego
Padmini Rangamani is a Professor in Mechanical Engineering at the University of California, San Diego. She joined the department in July 2014. Earlier, she was a UC Berkeley Chancellor’s Postdoctoral Fellow, where she worked on lipid bilayer mechanics. She obtained her Ph.D. in biological sciences from the Icahn School of Medicine at Mount Sinai. She received her B.S. and M.S. in Chemical Engineering from Osmania University (Hyderabad, India) and Georgia Institute of Technology respectively. She is the recipient of the PECASE, ARO, AFOSR, and ONR Young Investigator Awards, and a Sloan Research Fellowship for Computational and Molecular Evolutionary Biology. She is also the lead PI for a MURI award on Bioinspired low energy information processing from the AFOSR. She was recently elected to the College of Fellows of AIMBE.More about Prof. Padmini Rangamani