A Stochastic model for dynamics of FtsZ filaments and the formation of Z-ring

TL;DR

This paper introduces a stochastic model that captures the polymerization, ring formation, and depolymerization dynamics of FtsZ filaments, providing insights into bacterial cell division mechanisms.

Contribution

It presents a minimal stochastic model incorporating ring breaking and hydrolysis, offering new understanding of FtsZ filament dynamics and Z-ring stability.

Findings

The model reproduces in vitro FtsZ polymerization and ring formation observations.

Ring breaking dynamics induce rescue and catastrophe events.

Additional regulation mechanisms for FtsZ dynamics are identified.

Abstract

Understanding the mechanisms responsible for the formation and growth of FtsZ polymers and their subsequent formation of the $Z$-ring is important for gaining insight into the cell division in prokaryotic cells. In this work, we present a minimal stochastic model that qualitatively reproduces {\it in vitro} observations of polymerization, formation of dynamic contractile ring that is stable for a long time and depolymerization shown by FtsZ polymer filaments. In this stochastic model, we explore different mechanisms for ring breaking and hydrolysis. In addition to hydrolysis, which is known to regulate the dynamics of other tubulin polymers like microtubules, we find that the presence of the ring allows for an additional mechanism for regulating the dynamics of FtsZ polymers. Ring breaking dynamics in the presence of hydrolysis naturally induce rescue and catastrophe events in this model irrespective of the mechanism of hydrolysis.