Research groups
 
TEAM VI – Cell biophysics and biomimetism
 
Team leader : Catherine Picart, Associate Professor, UMII
 
Rachel Cerdan, Assistant Professor, UMII
Andrea Parmeggiani, Assistant Professor UMII
 
This new team is working at the interface between physics, biochemistry and cellular biology. The objectives of our work are to understand how components located at the interface between the cytoskeleton and the plasma membrane do interact and how a cell interacts with its environment (cell/substrate interaction). We particularly focus on proteins and lipids involved in cell morphogenesis and cell deformability. We are using biophysical methods such as various types of microscopies (optical, fluorescence, atomic force) and modelization for analysing the role of physical parameters, which play a role in the physico-chemical properties of cell membranes. The choice of the biological systems investigated is based on the results obtained by other teams of the lab.
First, we will investigate interactions between ERM (ezrin, radoxin, moesin) and a key membrane lipid, the phosphatidylinositol 4-5, bisphosphate (PIP2) (see work of team III) and with the hyaluronan receptor CD44. In order to better understand the interactions between these components and to carefully analyze the different steps of these interactions, we will be working on biomimetic vesicles containing a limited number of components and in which parameters will be systematically varied. The vesicle will also be submitted to local deformation by means of aspiration into a micropipette in order to study the components reorganization and dynamics under tension. Stiffness measurements of the cytoskeleton/plasma membrane interface will also be performed. One application is deformability of red blood cells infected by P. Falciparum (team II) and proteins involved in macrophages/red blood cell interactions (team I).
These experiments will be associated to modelizations in order to extract quantitative parameters.
Projects will be done in local collaborations with physicists and biophysicists from the « Laboratoire de Colloides, Verres and Nanomatériaux » and from the “Centre de Biochimie Structurale”.
 
National collaborations
- Jacques Ohayon (Professor at the University of Savoie) : micropipette experiments to investigate mechanical properties of supported gels.
- Bernard Senger (INSERM researcher) : modelling the fluorescence recovery after photobleaching experiments
 
International collaborations
- Dennis Discher (Professeur, University of Pennsylvania, Philadelphie) : “Stem cells sense substrate stiffness : new materials for mechanism and application” with C. Picart in the framework of a NIH-R21 contract (avril 2005- avril 2007)