Luca Dall'Asta — Politecnico di Torino #
Molecular sorting in the cell: self-organization and optimality #
Cell functionality requires continuous internalization of proteins and
other molecular factors that are transported to specialized compartments
(endosomes) by means of vesicles. Vesicle transport is characterized by an
accurate selection of only the desired molecules into the vesicles and
their subsequent transport towards the correct target. We describe the
first stage of this process (“molecular sorting”) using a minimal lattice
gas model for distillation of a single molecular factor on a lipid
membrane. The affinity between similar molecular factors favors the
formation of enriched domains that grow over time following classical
coarsening laws. Enriched domains are then extracted by means of vesicles.
At the steady-state, the efficiency of the sorting process depends on the
incoming flux of molecules and on their affinity. An optimal behavior is
identified, corresponding to the existence of a unique enriched domain.
Preliminary experimental validations of the theoretical (and numerical)
results are provided.