Mechanics Matters… For Biological Processes on the Nanoscale

A cell is not just a small test tube in which biochemical reactions take place, but it also has a complex and highly dynamic mechanical structure. I will discuss the underlying physical principles that govern cellular mechanics on the nanoscale, and explore how DNA mechanics, on its own and within the context of a heavily crowded, constrained and perpetually fluctuating cellular environment, affects biological function. For example, forces of less than hundred femtonewtons can mechanically switch genes on and off by preventing the formation of regulatory DNA-protein complexes. Special emphasis will be placed on the role of intracellular fluctuations and noise, as our data indicate that active non-equilibrium fluctuations from molecular motor action, as opposed to purely thermal noise, may play a crucial role in efficiently assembling the genetic machinery.