title: Formin mDia1 senses and generates mechanical forces on actin filaments.
abstract: Cytoskeleton assembly is instrumental in the regulation of biological functions by physical forces. In a number of key cellular processes, actin filaments elongated by formins such as mDia are subject to mechanical tension, yet how mechanical forces modulate the assembly of actin filaments is an open question. Here, using the viscous drag of a microfluidic flow, we apply calibrated piconewton pulling forces to individual actin filaments that are being elongated at their barbed end by surface-anchored mDia1 proteins. We show that mDia1 is mechanosensitive and that the elongation rate of filaments is increased up to two-fold by the application of a pulling force. We also show that mDia1 is able to track a depolymerizing barbed end in spite of an opposing pulling force, which means that mDia1 can efficiently put actin filaments under mechanical tension. Our findings suggest that formin function in cells is tightly coupled to the mechanical activity of other machineries.
authors.affiliation: Laboratoire d'Enzymologie et Biochimie Structurales, CNRS, avenue de la Terrasse, 91190 Gif-sur-Yvette, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Jégou
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Carlier
authors.forename: Guillaume
authors.initials: G
authors.lastname: Romet-Lemonne
mesh_terms: D008841:Actin Cytoskeleton / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D001696:Biomechanical Phenomena; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D000080865:Formins; D006801:Humans; D051379:Mice; D044085:Microfluidics; D058105:Polymerization; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D011817:Rabbits; D012212:Rheology; D014783:Viscosity
chemical_list: D002352:Carrier Proteins; C491464:Diap1 protein, mouse; D000080865:Formins; D000244:Adenosine Diphosphate