Bistability of cell-matrix adhesions resulting from non-linear receptor-ligand dynamics
Thorsten Erdmann 1 and Ulrich S Schwarz 1*
1 Heidelberg University
* To whom correspondence should be addressed. E-mail: ulrich.schwarz{at}iwr.uni-heidelberg.de.
Submitted on June 9, 2006
Revised on June 18, 2006
Accepted on 30 June 2006
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Abstract |
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Bistability is a major mechanism for cellular decision making and usually results from positive feedback in biochemical control systems. Here we show theoretically that bistability between unbound and bound states of adhesion clusters results from positive feedback mediated by structural rather than biochemical processes, namely by receptor-ligand dissociation and association dynamics which depend non-linearly on mechanical force and receptor-ligand separation. For small cell-matrix adhesions, we find rapid switching between unbound and bound states, which in the initial stages of adhesion allows the cell to explore its environment through many transient adhesions.
Key Words:
bifurcation analysis, bond rupture and rebinding, cell-matrix adhesion, integrins, stochastic dynamics
