Active beating of a reconstituted synthetic minimal axoneme

TL;DR

This paper reports the creation of a minimal synthetic axoneme, called a synthoneme, which mimics ciliary beating through energy-driven rhythmic bending of microtubules using dynein motors.

Contribution

It introduces a bottom-up assembly of a minimal biomolecular machine that reproduces ciliary beating using natural biological components.

Findings

Microtubules undergo rhythmic bending upon ATP energy supply.

Dynein motors drive cyclic association-dissociation leading to oscillatory motion.

The synthoneme mimics key features of natural ciliary beating.

Abstract

Propelling microorganisms through fluids and moving fluids along cellular surfaces are essential biological functions accomplished by long, thin structures called motile cilia and flagella, whose regular, oscillatory beating breaks the time-reversal symmetry required for transport. Although top-down experimental approaches and theoretical models have allowed us to broadly characterize such organelles and propose mechanisms underlying their complex dynamics, constructing minimal systems capable of mimicking ciliary beating and identifying the role of each component remains a challenge. Here we report the bottom-up assembly of a minimal synthetic axoneme, which we call a synthoneme, using biological building blocks from natural organisms, namely pairs of microtubules and cooperatively associated axonemal dynein motors. We show that upon provision of energy by ATP, microtubules undergo rhythmic bending by cyclic association-dissociation of dyneins. Our simple and unique beating minimal synthoneme represents a self-organized nanoscale biomolecular machine that can also help understand the mechanisms underlying ciliary beating.