Article

Control of actin assembly and disassembly at filament ends

Department of Cell Biology, Washington University, Box 8228, St Louis, MO 631110, USA.
Current Opinion in Cell Biology (Impact Factor: 8.47). 03/2000; 12(1):97-103. DOI: 10.1016/S0955-0674(99)00062-9
Source: PubMed

ABSTRACT

The most important discovery in the field is that the Arp2/3 complex nucleates assembly of actin filaments with free barbed ends. Arp2/3 also binds the sides of actin filaments to create a branched network. Arp2/3's nucleation activity is stimulated by WASP family proteins, some of which mediate signaling from small G-proteins. Listeria movement caused by actin polymerization can be reconstituted in vitro using purified proteins: Arp2/3 complex, capping protein, actin depolymerizing factor/cofilin, and actin. actin depolymerizing factor/cofilin increases the rate at which actin subunits leave pointed ends, and capping protein caps barbed ends.

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Available from: Dorothy A Schafer, Feb 05, 2014
    • "We analyzed the effects of P 4 in cofilin phosphorylation, which is important to induce the formation of plus actin ends [48]. The formation of the plus actin ends is essential in the dynamic remodeling of the actin cytoskeleton, since the polymerization of new actin filaments that lead to the formation of protrusions during the early stages of cell motility occurs in these ends [49]. In some studies, it has been observed that P 4 is capable of modifying cell morphology and that these events are conducted through rearrangements of the actin cytoskeleton through changes in the phosphorylation state of ABPs [25,50]. "
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    • "If G-actin levels fall below the critical concentration, no more polymerization takes place. The maintenance of the actin pool necessitates the depolymerization of existing actin filaments which appears to be facilitated by different supporting proteins such as ADF and cofilin [124] [125]. "
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    • "Cell migration requires a number of changes, e.g. the reorganization of the actin cytoskeleton (Mogilner and Edelstein-Keshet, 2002), changes in cell shape and in activity of various cytokines and growth factors. On the other hand, proper organization of the cell cytoskeleton is essential for a number of fundamental processes in cells including proliferation, migration, differentiation, signal transmission or regeneration (Cooper and Schafer, 2000; Mogilner and Edelstein-Keshet, 2002; Pollard and Borisy, 2003). There are several reports indicating significant disruption of the hepatocyte actin cytoskeleton caused by MC-LR (Runnegar et al., 1995; Toivola and Eriksson, 1999; Batista et al., 2003). "
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