Figure 1: Pulling on actin filaments with the viscous drag of a flowing fluid.
From: Formin mDia1 senses and generates mechanical forces on actin filaments
(a) The force exerted by the flowing fluid on an actin filament is measured with a microbead in an optical trap, a few micrometres above the surface. Data points and error bars show the averages and s.d. of 47 measurements, performed with different filament lengths and different flow velocities. (b) Filaments anchored to the bottom of the microfluidic chamber fluctuate around an average position located 250 nm above the surface, resulting in rapid fluctuations of the force exerted on the anchoring point. Histograms show the force distributions for a 14-μm long filament in a flow velocity gradient of 194 s−1 (red bars, force=0.40±0.16 pN) and for a 20-μm long filament in a flow velocity gradient of 565 s−1 (blue bars, force=1.63±0.53 pN).
