How does local cell curvature influence polar cap size ?

Polarisation in yeast cells consists of an aggregation of proteins (here CdC42) on the membrane which becomes asymmetric. The two main mechanisms involved in the breaking of symmetry in this process seem to be : -reaction-diffusion mechanism -actin mediated transport Experiments have shown that the polar cap size depends on the local curvature of the affected cell and more precisely that it is the actin mediated transport which is crucial to obtain this correlation. The aim of this talk is to give some hypotheses which may explain the mechanisms underlying this correlation. To this, we in particular use a mathematical model in order to test different components in reaction diffusions and actin transport mechanisms which may influence the cap size of cDc42. This work is made in collaboration with D. Bonazzi and N. Minc from the Institut Jacques Monod, part of Université Paris Diderot.