Abstract：
:The comet motility assay, inspired by Listeria locomotion, has been used extensively as an in vitro model to study the structural and motile properties of the actin cytoskeleton. However, there are no quantitative measurements of the mechanical properties of these actin comets. In this work, we use nanoindentation based on atomic force microscopy to measure the elastic modulus of actin comets grown on 1-μm-diameter beads in an Arp2/3 (actin-related proteins 2 and 3)-complex-dependent fashion in the absence and in the presence of VASP (vasodilator-stimulated phosphoprotein). Recruitment of VASP to the bead surface had no effect on the initial velocity or morphology of the comets. Instead, we observed an improved contact of the comets with the beads and an increased elastic modulus of the comets. The VASP-mediated increase in elastic modulus was dependent on both concentration and ionic strength. In conclusion, we propose that VASP plays a mechanical role in Arp2/3-complex-dependent motility by amplifying the elastic modulus of the thus assembled actin network and, consequently, by strengthening its cohesion for persistent protrusion.
journal_name
J Mol Bioljournal_title
Journal of molecular biologyauthors
Suei S,Seyan R,Noguera P,Manzi J,Plastino J,Kreplak Ldoi
10.1016/j.jmb.2011.08.054subject
Has Abstractpub_date
2011-10-28 00:00:00pages
573-83issue
3eissn
0022-2836issn
1089-8638pii
S0022-2836(11)00966-1journal_volume
413pub_type
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