Publication Date:
2008-12-17
Description:
Cells sense the environment's mechanical stiffness to control their own shape, migration, and fate. To better understand stiffness sensing, we constructed a stochastic model of the "motor-clutch" force transmission system, where molecular clutches link F-actin to the substrate and mechanically resist myosin-driven F-actin retrograde flow. The model predicts two distinct regimes: (i) "frictional slippage," with fast retrograde flow and low traction forces on stiff substrates and (ii) oscillatory "load-and-fail" dynamics, with slower retrograde flow and higher traction forces on soft substrates. We experimentally confirmed these model predictions in embryonic chick forebrain neurons by measuring the nanoscale dynamics of single-growth-cone filopodia. Furthermore, we experimentally observed a model-predicted switch in F-actin dynamics around an elastic modulus of 1 kilopascal. Thus, a motor-clutch system inherently senses and responds to the mechanical stiffness of the local environment.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Chan, Clarence E -- Odde, David J -- R01-GM-76177/GM/NIGMS NIH HHS/ -- New York, N.Y. -- Science. 2008 Dec 12;322(5908):1687-91. doi: 10.1126/science.1163595.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/19074349" target="_blank"〉PubMed〈/a〉
Keywords:
Actin Cytoskeleton/*physiology
;
Actins/*physiology
;
Animals
;
Biomechanical Phenomena
;
Cell Adhesion
;
Cells, Cultured
;
Chick Embryo
;
Compliance
;
Computer Simulation
;
Elastic Modulus
;
Elasticity
;
Growth Cones/*physiology/ultrastructure
;
Models, Biological
;
Myosin Type II/physiology
;
Neurons/physiology
;
Pseudopodia/*physiology
;
Surface Tension
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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