Rapid assembly of a polar network architecture drives efficient actomyosin contractility

Vlad Costache (1, 2) , Serena Prigent Garcia (1, 2) , Camille N Plancke (1, 2) , Jing Li (3) , Simon Begnaud (1, 2) , Shashi Kumar Suman (1, 2) , Anne-Cécile Reymann (4) , Taeyoon Kim (3) , François B Robin (2, 1)

1 IBPS - Institut de Biologie Paris Seine
2 LBD - Laboratoire de Biologie du Développement [IBPS]
3 Purdue University [West Lafayette]
4 IGBMC - Institut de Génétique et de Biologie Moléculaire et Cellulaire

Actin network architecture and dynamics play a central role in cell contractility and tissue morphogenesis. RhoA-driven pulsed contractions are a generic mode of actomyosin contractility, but the mechanisms underlying how their specific architecture emerges and how this architecture supports the contractile function of the network remain unclear. Here we show that, during pulsed contractions, the actin network is assembled by two subpopulations of formins: a functionally inactive population (recruited) and formins actively participating in actin filament elongation (elongating). We then show that elongating formins assemble a polar actin network, with barbed ends pointing out of the pulse. Numerical simulations demonstrate that this geometry favors rapid network contraction. Our results show that formins convert a local RhoA activity gradient into a polar network architecture, causing efficient network contractility, underlying the key function of kinetic controls in the assembly and mechanics of cortical network architectures.

Mots clés: CP: cell biology; actomyosin; cell mechanics; cytoskeleton; formin; kinetics; live microscopy; mDia; numerical simulations; single-molecule microscopy

Domaines: Sciences du Vivant [q-bio]

Vlad Costache, Serena Prigent Garcia, Camille N Plancke, Jing Li, Simon Begnaud, et al.. Rapid assembly of a polar network architecture drives efficient actomyosin contractility. Cell Reports, 2022, 39 (9), pp.110868. ⟨10.1016/j.celrep.2022.110868⟩. ⟨hal-03874348⟩