Journal
CELL ADHESION & MIGRATION
Volume 2, Issue 2, Pages 58-68Publisher
TAYLOR & FRANCIS INC
DOI: 10.4161/cam.2.2.6190
Keywords
actin cytoskeleton; Arp 2/3 complex; cell adhesion; cell spreading; Coronin; Dictyostelium; myosin; self-organization; clathrin
Categories
Funding
- Deutsche Forschungsgemeinschaft
- Max-Planck-Gesellschaft
- Microsoft Corporation
Ask authors/readers for more resources
The spreading of motile cells on a substrate surface is accompanied by reorganization of their actin network. We show that spreading in the highly motile cells of Dictyostelium is non-monotonic, and thus differs from the passage of spreading cells through a regular series of stages. Quantification of the gain and loss of contact area revealed fluctuating forces of protrusion and retraction that dominate the interaction of Dictyostelium cells with a substrate. The molecular basis of these fluctuations is elucidated by dual-fluorescence labeling of filamentous actin together with proteins that highlight specific activities in the actin system. Front-to-tail polarity is established by the sorting out of myosin-II from regions where dense actin assemblies are accumulating. Myosin-IB identifies protruding front regions, and the Arp2/3 complex localizes to lamellipodia protruded from the fronts. Coronin is used as a sensitive indicator of actin disassembly to visualize the delicate balance of polymerization and depolymerization in spreading cells. Short-lived actin patches that co-localize with clathrin suggest that membrane internalization occurs even when the substrate-attached cell surface expands. We conclude that non-monotonic cell spreading is characterized by spatiotemporal patterns formed by motor proteins together with regulatory proteins that either promote or terminate actin polymerization on the scale of seconds.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available