How the Load and the Nucleotide State Affect the Actin Filament Binding Mode of the Molecular Motor Myosin V
Sergey V Mikhailenko1, Yusuke Oguchi, Takashi Ohki
1Department of Physics, Faculty of Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan.
Abstract:
The interaction between actin and myosin V has been probed by measuring the unbinding force of individual actomyosin complexes using optical tweezers. Surprisingly, we found that in both the nucleotide-free and ADP-bound states single- and double-headed binding occurs with approximately the same probability. Estimation of the spring constant of individual actomyosin complexes confirmed that in each of the nucleotide states two distinct populations exist. These results confirm that optical nanometry can be used to reliably study the mechanism of how cytoskeleton molecular motors interact with their associated polymer lattices under solution conditions more closely resembling the intracellular environment.
Related Concept Videos
Actin and Myosin in Muscle Contraction
Overview of Myosin Structure and Function
Generation of Straight or Branched Actin Filaments
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Introduction to Actin
Actin Filament Depolymerization
In F-actin, the ADF/cofilin proteins...
Actin Polymerization
The nucleation phase involves forming a stable nucleus consisting of three actin monomers to form a new actin filament. Actin-binding proteins such as formins and Arp2/3 complex help filament growth post-nucleation. The Formins form straight actin...


