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Cell. 1993 Dec 3;75(5):1007-14.

How profilin promotes actin filament assembly in the presence of thymosin beta 4.

Author information

1
Laboratoire d'Enzymologie Centre National de la Recherche Scientifique, Gif-sur-Yvette, France.

Abstract

The role of profilin in the regulation of actin assembly has been reexamined. The affinity of profilin for ATP-actin appears 10-fold higher than previously thought. In the presence of ATP, the participation of the profilin-actin complex to filament elongation at the barbed end is linked to a decrease in the steady-state concentration of globular actin. This surprising effect is made possible by the involvement of the irreversible ATP hydrolysis accompanying actin polymerization. As a consequence, in the presence of thymosin beta 4 (T beta 4), low amounts of profilin promote extensive actin assembly off of the pool of actin-T beta 4 complex. When barbed ends are capped, profilin simply sequesters globular actin. A model is proposed for the function of profilin in actin-based motility.

PMID:
8252614
DOI:
10.1016/0092-8674(93)90544-z
[Indexed for MEDLINE]

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