PT - JOURNAL ARTICLE AU - Charlotta Lorenz AU - Johanna Forsting AU - Anna V. Schepers AU - Julia Kraxner AU - Susanne Bauch AU - Hannes Witt AU - Stefan Klumpp AU - Sarah Köster TI - Lateral Subunit Coupling Determines Intermediate Filament Mechanics AID - 10.1101/676197 DP - 2019 Jan 01 TA - bioRxiv PG - 676197 4099 - http://biorxiv.org/content/early/2019/06/19/676197.short 4100 - http://biorxiv.org/content/early/2019/06/19/676197.full AB - The cytoskeleton is a composite network of three types of protein filaments, among which in-termediate filaments (IFs) are the most extensible ones. Two very important IFs are keratin and vimentin, which have similar molecular architectures, but different mechanical behaviors. Here we compare the mechanical response of single keratin and vimentin filaments using optical tweezers. We show that the mechanics of vimentin strongly depends on the ionic strength of the buffer and that its force-strain curve suggests a high degree of cooperativity between subunits. Indeed, a computational model indicates that in contrast to keratin, vimentin is characterized by strong lateral subunit coupling of its charged monomers during unfolding of α-helices. We conclude that cells can tune their mechanics by differential use of keratin versus vimentin.