Processive acceleration of actin barbed-end assembly by N-WASP.

ABSTRACT: Neuronal Wiskott-Aldrich syndrome protein (N-WASP)-activated actin polymerization drives extension of invadopodia and podosomes into the basement layer. In addition to activating Arp2/3, N-WASP binds actin-filament barbed ends, and both N-WASP and barbed ends are tightly clustered in these invasive structures. We use nanofibers coated with N-WASP WWCA domains as model cell surfaces and single-actin-filament imaging to determine how clustered N-WASP affects Arp2/3-independent barbed-end assembly. Individual barbed ends captured by WWCA domains grow at or below their diffusion-limited assembly rate. At high filament densities, however, overlapping filaments form buckles between their nanofiber tethers and myosin attachment points. These buckles grew ∼3.4-fold faster than the diffusion-limite

SUBMITTER: Khanduja N 

PROVIDER: S-EPMC3873893 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature