COMPUTATIONAL INVESTIGATION OF DYNAMIC PROPERTIES OF ACTIN NETWORKS WITH CROSSLINKING PROTEINS

摘要

Due to the increasing recognition of the role that force plays in biological processes, a new field, mechanobiology, has recently emerged. One aspect of this is the need to gain a physical understanding of the viscoelastic properties of the cytoskeleton. Numerous studies, both in living cells and in reconstituted actin gels, have been conducted, but important questions still remain. Of these an important issue revolves around the role played by actin crosslinking proteins (ACPs), and whether they undergo unfolding or unbinding under stress. This issue is complicated by the fact that single molecule studies show that both events occur within a similar range of forces, on the order of 20-100 pN.rnWe have taken the approach that greater insight can be gained by the use of a geometrically-realistic three-dimensional (3D) computational model that accurately portrays the elastic properties of the actin filaments and crosslinking proteins, that allows for unbinding and unfolding kinetics of ACPs, and that is thermally active. We have recently published some aspects of this model and extend it here to examine issues related to crosslink dynamics.