Myosin-I synergizes with Arp2/3 complex to enhance the pushing forces of branched actin networks

• DOI: 10.1126/sciadv.ado5788
• Publication Date: 2024-09-13T17:59:31Z
• Authors: Mengqi Xu; David M. Rutkowski; Grzegorz Rebowski; Malgorzata Boczko...; Luther W. Pollard; Roberto Dominguez; Dimitrios Vavylonis; E. Michael Ostap
• Keywords: Actin remodeling; Molecular motor

Class I myosins (myosin-Is) colocalize with Arp2/3 complex–nucleated actin networks at sites of membrane protrusion and invagination, but the mechanisms by which myosin-I motor activity coordinates branched assembly to generate force are unknown. We mimicked interplay these proteins using “comet tail” bead motility assay, where nucleated complex on surface beads coated nucleation-promoting factor. observed that increased movement efficiency thinning without affecting growth rates. Myosin-I triggered symmetry breaking comet tail formation in dense resistant spontaneous fracturing. Even arrested assembly, alone could break network. Computational modeling recapitulated observations, suggesting acts as a repulsive shaping network’s architecture boosting its force-generating capacity. propose leverages power stroke amplify forces generated networks.