Filamin cross-linked semiflexible networks: fragility under strain.
The semiflexible F-actin network of the cytoskeleton is cross-linked by a variety of proteins including filamin, which contains Ig domains that unfold under applied tension. We examine a simple filament network model cross-linked by such unfolding linkers that captures the main mechanical features of F-actin networks cross-linked by filamin proteins and show that, under sufficient strain, the network spontaneously self-organizes so that an appreciable fraction of the filamin cross-linkers are at the threshold of domain unfolding. We propose and test a mean-field model to account for this effect. We also suggest a qualitative experimental signature of this type of network reorganization under applied strain that may be observable in intracellular microrheology experiments of Crocker et al.
DiDonna
B A
BA
Institute for Mathematics and Its Applications, University of Minnesota, Minneapolis, Minnesota 55455-0436, USA.
Levine
Alex J
AJ
D000199:Actins / Q000737:chemistry*; D003198:Computer Simulation; D003285:Contractile Proteins / Q000737:chemistry*; D004548:Elasticity; D064448:Filamins; D008840:Microfilament Proteins / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D046912:Multiprotein Complexes / Q000737:chemistry / Q000648:ultrastructure; D011487:Protein Conformation; D013314:Stress, Mechanical
D000199:Actins; D003285:Contractile Proteins; D064448:Filamins; D008840:Microfilament Proteins; D046912:Multiprotein Complexes