# Stress relaxation in F-actin solutions by severing

## TL;DR

This paper presents a theoretical model explaining how actin filament severing proteins influence stress relaxation in F-actin solutions, highlighting the roles of assembly, disassembly, and severing kinetics in different relaxation behaviors.

## Contribution

It introduces a novel theoretical framework that captures the effects of severing proteins on the stress relaxation dynamics of actin networks.

## Key findings

- Stress relaxation can be length-dependent or length-independent.
- Kinetic rates of assembly, disassembly, and severing determine relaxation behavior.
- The model aligns with recent rheological experimental observations.

## Abstract

Networks of filamentous actin (F-actin) are important for the mechanics of most animal cells. These cytoskeletal networks are highly dynamic, with a variety of actin-associated proteins that control cross-linking, polymerization and force generation in the cytoskeleton. Inspired by recent rheological experiments on reconstituted solutions of dynamic actin filaments, we report a theoretical model that describes stress relaxation behavior of these solutions in the presence of severing proteins. We show that depending on the kinetic rates of assembly, disassembly, and severing, one can observe both length-dependent and length-independent relaxation behavior.