%0 Journal Article %A Julien Pernier %A Remy Kusters %A Hugo Bousquet %A Thibaut Lagny %A Antoine Morchain %A Jean-François Joanny %A Patricia Bassereau %A Evelyne Coudrier %T A new actin depolymerase: a catch bond Myosin 1 motor %D 2018 %R 10.1101/375923 %J bioRxiv %P 375923 %X The regulation of actin dynamics is essential for various cellular processes. Former evidence suggests a correlation between the function of non-conventional myosin motors and actin dynamics. We investigate the contribution of the catch-bond Myosin1b to actin dynamics using sliding motility assays. We observe that sliding on Myosin1b immobilized or bound to a fluid bilayer enhances actin depolymerization at the barbed end, while sliding on the weak catch-bond MyosinII has no effect. Our theoretical model supports that the catch-bond prolongs the attachment time of the motor at the barbed end due to the friction force exerted by the sliding filament; thereby this motor exerts a sufficient force on this end to promote depolymerization. This work reveals a non-conventional myosin motor as a new type of depolymerase.Sentence summary Due to its catch bond, Myosin 1b depolymerizes sliding actin filaments at their barbed end by exerting a prolonged force. %U https://www.biorxiv.org/content/biorxiv/early/2018/07/24/375923.full.pdf