Download Shape matters in protein mobility within membranes - ICAM

Shape matters in protein mobility within membranes
David Lacoste , Laboratoire de Physico-Chimie Théorique
Lateral Brownian diffusion of proteins in lipid membranes has
been predicted by Saffman and Delbrück to depend only on
protein size and on the viscosity of the membrane and of the
surrounding medium. Using a single-molecule tracking technique
on two transmembrane proteins that bend the membrane
differently and are reconstituted in giant unilamellar
vesicles, we show that the mobility of a membrane protein is
crucially dependent on the local membrane deformation self-generated
around the protein, which can be tuned by adjusting
membrane tension [1]. The feedback between membrane shaping
and mobility is well explained by analytical and numerical
models that include the friction of the deformed membrane
patch with the surrounding medium and the friction internal to
the bilayer. Extensions of this framework to other types of coupling
between the membrane and the protein will be discussed [2].
[1] F. Quemeneur, J.K. Sigurdsson, M. Renner, P.J. Atzberger, P. Bassereau and D.
Lacoste, PNAS 111, 5083 (2014)
[2] V. Démery and D. Lacoste, chapter in book "Physics of biological membranes",
published by Springer Netherlands