Steady state dynamics of a moving model cell.
Crawling cell motility results due to treadmilling of a polymerized actin network at the leading edge. Steady state dynamics of a moving cell are governed by actin concentration profiles across the cell. Branching of new filaments implicating Arp2/3 and capping of existing filaments with capZ or Gelsolin are central to the robust functioning of the actin network. Using computer simulations, steady state concentration profiles of globular actin (G actin) and filamentous actin (F actin) are computed. The profiles are in agreement with experimentally observed ones. Simulations unveil that there is an optimal capping and branching rate for which the velocity of the model cell is maximum. Our simulations also indicate that the capping of actin filaments results in an increase in nucleation of new filaments by Arp2/3-induced branching and is in agreement with a recently observed monomer gating model. We observe that Arp2/3 and capping protein exhibit a functional antagonism with respect to the actin network treadmilling.
Department of Physics, Pondicherry University, Puducherry 605 014, India.
Antony
A
Simon
S V M
SV
Satyanarayana
D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism; D000199:Actins / Q000737:chemistry / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002465:Cell Movement; D004058:Diffusion; D008954:Models, Biological; D009010:Monte Carlo Method; D011336:Probability; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D013997:Time Factors
D051376:Actin-Related Protein 2-3 Complex; D000199:Actins