A generalized clutch model to explain cell adhesion mechanics

Integrin-based cell adhesion is a key mechanism in a large number of physiological processes and diseases. The composition and nanoscale organization of adhesion complexes have shown that the integrin-talin-actin chain plays a central role in the formation of small nascent adhesion and further maturation into focal adhesions. The role of ligand spacing and substrate rigidity has been also clearly demonstrated. Clutch models have been widely used to describe how cell adhesion works. However, they have not been capable of rationalizing many of the aspects described above; probably, because current clutch models are built under a number of simplifications of the adhesion mechanisms. Here, we extend the classical clutch model with a detail description of the talin rod as well as a space-dependent ligand distribution. We will show the minimal building block and adhesion length of focal adhesion. Following the same computational model, we will also show that focal adhesion forms for stiff substrates for low spacing while they form in soft substrates for large spacing. In summary, we proposed a model that unifies our current understanding of cell adhesion architecture and turnover while replicating previous experimental results.