Tuning intermediate filament mechanics by variation of pH and ion charges

Abstract

<p>The mechanical properties of intermediate filaments depend on pH and ion concentration, providing cells with tools to tune their mechanics.</p>

Post-translational modifications soften vimentin intermediate filaments

“…For a lower pH, we expect the same shape of the curve, but slightly shifted to higher forces, as shown recently in Ref. 17. Such a typical curve for our standard condition is shown in Fig.…”

“…An effective way to tune the mechanics of intermediate filaments is the variation of the charges of the amino acids constituting the protein 17 . One cellular mechanism for such charge variation are post-translational modifications (PTMs).…”

Bend, Push, Stretch: Remarkable Structure and Mechanics of Single Intermediate Filaments and Meshworks

“…Interestingly, the tail domain carries four negatively charged residues and two histidines. Ion concentration and also pH may fine-tune the delicate interplay between the complex IF networks in the cell in response to the barrage of forces [115].…”

Optical Tweezers Approaches for Probing Multiscale Protein Mechanics and Assembly

“…Lateral association into higher-order protein fibers produces structures that are stiffer than their individual protein components. The Young’s modulus of such structures is significantly larger than the elastic modulus (proportional to stiffness) of typical optical traps, meaning only high-intensity OT have been used to perform meaningful strain measurements on fibers ( Nabiev et al, 2015 ; Block et al, 2017 , 2018 ; Schepers et al, 2020 ). A disadvantage of high-intensity optical traps is the local heating of the sample that can result ( Neuman and Nagy, 2008 ).…”