theoretical model of cellular shape dynamics and motility, coupling curvature and
simple model component : cell membrane deformation / active forces / curved membrane activators.
several convex proteins that recruit actins
linear-stability analysis : limited to small perturbation, no way to tell how the shape will be at finite time
check review in 2018 by him
minimal model for MC simulation (Monte Carlo)
local curvature, spontaneous curvature ⇒ bending energy plus protein-protein binding energy
active forces from cytoskeleton : non-equilibrium
this system doesn’t consider any fluid dynamics it only tells which way the system will lower its energy
case#1
passive, isotropic curved proteins: pearled-chains in2017
pancake shape to minimize bending energy in 2021 from the model, by only applying the protrusion forces, the cells can spread into pancake at , at it is not as effective
but low density of such protein can still promote motility
crescent shape is the leading edge, and cells cannot move into 2 split crescent direction. in simulation, cells will stop, in real, cells have mechanism to repolarize
case#2
cells moving on curved surfaces wave like shapes of substrate
cells like to move in grooves with cells shape smaller than wavelength
if cells are larger, cells like to move across patterns
so they put cells on a rod which has fixed curvature cells will circumferential orientation which allows the leading edge to stretch the membrane sideways along the low curvature direction
supported by 2015 phd thesis also from carsten beta in 2024 PNAS
radius too small → not coiling myelination
case#3
difference of sheet like protrusions or finger like protrusions
filopodia by bundled actin so they mimic it by aligning the force direction of neighbors
put 2 types of force production together, there is traffic issue to inhibit filopodia formation in lamellipodia region