Research Seminar: Understanding cell shape: reconstituting the actin-membrane interace.

Dr. Jenny Gallop, Wellcome Trust/Cancer Research UK Gurdon Institute, University of Cambridge

Wednesday 17th December, 4.00 p.m., Stacey Lecture Theatre 1

Membranes are central organizing surfaces for signaling and actin polymerization in the control of cell shape and movement. My work uses artificial membrane systems and frog egg extracts in real time assays to delineate and reconstitute the biochemical events underlying the membrane-localized assembly of actin. By using PI(4,5)P2 containing supported lipid bilayers on glass we were able to form actin structures that resemble filopodia and show that they form by self-assembly of protein networks on a permissive membrane surface. By comparing the lipid specificities of actin polymerization from lipid bilayers of different curvature we have identified how signals from membrane curvature and composition can be combined to recruit different adaptor proteins during endocytosis, which then co-opt more general actin machinery. We are beginning to understand how the cell can form actin structures of different types within a common cytosol.

 SPONSORED BY CAIRN RESEARCH.