LMGP_IMBM_Insuline at triple interface 2022

ERM binding to biomimetic membranes

Contact : Ezrin, member of the ezrin/radixin/moesin (ERM) family, is a membrane cytoskeleton linker involved in the cellular morphogenesis and motility. Ezrin switches dynamically between the cytosol where it is under a dormant state and the membrane, once activated (open conformation). The activation process requires its interaction with a specific lipid, phosphatidylinositol-4,5-bisphophate (PIP2) and/or phosphorylations at specific sites. The membrane-associated ezrin can then interact with the actin cytoskeleton.

The aim of our project is to understand at the molecular level the link between membrane structures and the actin cytoskeleton.

We study in vitro using recombinant proteins the interplay between PIP2, ezrin and actin in biomimetic systems in order to get a better knowledge of the underlying important molecular processes.

The biomimetic systems cover a large range of sizes and shapes  : large unilamelar vesicles (LUVs), supported lipid bilayers (SLBs) and giant unilamellar vesicles (GUVs). Selected Publications  

  • Blin, G., Margeat, E., Carvalho, K., Royer, C.A., Roy, C., Picart, C. Quantitative analysis of the binding of ezrin to large unilamellar vesicles containing phosphatidylinositol(4,5) bisphosphate. Biophys. J. 95(3), 1021-1033, 2008.
  • Carvalho, K., Ramos, L., Roy, C., Picart, C. Giant unilamellar vesicles containing phosphatidylinositol(4,5)bisphosphate : characterization and functionality. Biophys. J. 95(9):4348-60, 2008.
  • Hamard-Péron, E, Hamard-Peron E, Juilliard F, Saad JS, Roy C, Roingeard P, Summers MF, Darlix JL, Picart C, Muriaux D. Targeting of MuLV Gag to the plasma membrane is mediated by PI(4,5)P2/PS and a polybasic region in the Matrix. J. Virol. 84 :503-515, 2010.
  • Carvalho, K., Khalifat, N., Maniti, O., Nicolas, C., Arold, S., Picart, C., Ramos, L. Phosphatidylinositol 4,5-bisphosphate-induced conformational change of ezrin and formation of ezrin oligomers. Biochemistry 49:9318-9327, 2010.
  •  Ben-Aissa, K., Palatino-Lopez, G., Belkina, N.V., Maniti, O., Rosales, T., Hao, J.J., Kruhlak, M.J., Knutson, J.R., Picart, C. and S. Shaw.  ERM protein activation by phosphatidylinositol 4,5-bisphosphates (PIP2): relationship between an auto-inhibitory acidic linker and two PIP2 binding sites required for activation. J. Biol. Chem. 2012, Ehead of print March 23th 2012.             

Collaborations  

  • Dr Laurence Ramos, LCVN, Montpellier, France
  • Dr Laurent Blanchoin, iRSTV-CEA Grenoble, France
  • Dr Delphine Muriaux, ENS Lyon, France
  • Dr Steve Shaw, NIH Bethesda, USA