Physics Colloquium - Effective Thermal Equilibrium Induced by Cross-Linking Proteins in Polymer Chromosome Models

Biological systems are a natural place to find far-from-equilibrium dynamics where ATP-mediated forces are at play. I will discuss one such system, the dynamics of yeast chromatin that displays equilibrium-like self-organized clusters despite the presence of crosslinking condensin proteins pushing the system out of equilibrium. Mathematically, different limits concerning the two sources of noise (randomly switching protein binding forces and thermal noise) produce different predictions for the behavior of the system. The one that accurately describes the results of numerical simulations suggests that the biological system may be taking advantage of the switching noise to produce metastable clusters.