Weak temporal signals can synchronize and accelerate the transition dynamics of biopolymers under tension

TL;DR

This study demonstrates that weak oscillatory forces can synchronize and accelerate RNA hairpin folding and unfolding transitions under tension, revealing a form of stochastic resonance relevant to cellular biopolymer dynamics.

Contribution

It shows that even weak, specific-frequency oscillations can enhance biopolymer transition rates, illustrating thermally induced resonance phenomena in RNA folding.

Findings

Weak oscillatory forces can synchronize RNA transition dynamics.

RNA can discriminate signals at resonance frequency amidst noise.

Resonant activation enhances transition rates even under high tension.

Abstract

In addition to thermal noise, which is essential to promote conformational transitions in biopolymers, cellular environment is replete with a spectrum of athermal fluctuations that are produced from a plethora of active processes. To understand the effect of athermal noise on biological processes, we studied how a small oscillatory force affects the thermally induced folding and unfolding transition of an RNA hairpin, whose response to constant tension had been investigated extensively in both theory and experiments. Strikingly, our molecular simulations performed under overdamped condition show that even at a high (low) tension that renders the hairpin (un)folding improbable, a weak external oscillatory force at a certain frequency can synchronously enhance the transition dynamics of RNA hairpin and increase the mean transition rate. Furthermore, the RNA dynamics can still discriminate a signal with resonance frequency even when the signal is mixed among other signals with nonresonant frequencies. In fact, our computational demonstration of thermally induced resonance in RNA hairpin dynamics is a direct realization of the phenomena called stochastic resonance (SR) and resonant activation (RA). Our study, amenable to experimental tests using optical tweezers, is of great significance to the folding of biopolymers in vivo that are subject to the broad spectrum of cellular noises.